1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26 /* Copyright (c) 1990 Mentat Inc. */
  27 
  28 #pragma ident   "%Z%%M% %I%     %E% SMI"
  29 const char tcp_version[] = "%Z%%M%      %I%     %E% SMI";
  30 
  31 
  32 #include <sys/types.h>
  33 #include <sys/stream.h>
  34 #include <sys/strsun.h>
  35 #include <sys/strsubr.h>
  36 #include <sys/stropts.h>
  37 #include <sys/strlog.h>
  38 #include <sys/strsun.h>
  39 #define _SUN_TPI_VERSION 2
  40 #include <sys/tihdr.h>
  41 #include <sys/timod.h>
  42 #include <sys/ddi.h>
  43 #include <sys/sunddi.h>
  44 #include <sys/suntpi.h>
  45 #include <sys/xti_inet.h>
  46 #include <sys/cmn_err.h>
  47 #include <sys/debug.h>
  48 #include <sys/sdt.h>
  49 #include <sys/vtrace.h>
  50 #include <sys/kmem.h>
  51 #include <sys/ethernet.h>
  52 #include <sys/cpuvar.h>
  53 #include <sys/dlpi.h>
  54 #include <sys/multidata.h>
  55 #include <sys/multidata_impl.h>
  56 #include <sys/pattr.h>
  57 #include <sys/policy.h>
  58 #include <sys/priv.h>
  59 #include <sys/zone.h>
  60 #include <sys/sunldi.h>
  61 
  62 #include <sys/errno.h>
  63 #include <sys/signal.h>
  64 #include <sys/socket.h>
  65 #include <sys/sockio.h>
  66 #include <sys/isa_defs.h>
  67 #include <sys/md5.h>
  68 #include <sys/random.h>
  69 #include <sys/sodirect.h>
  70 #include <sys/uio.h>
  71 #include <netinet/in.h>
  72 #include <netinet/tcp.h>
  73 #include <netinet/ip6.h>
  74 #include <netinet/icmp6.h>
  75 #include <net/if.h>
  76 #include <net/route.h>
  77 #include <inet/ipsec_impl.h>
  78 
  79 #include <inet/common.h>
  80 #include <inet/ip.h>
  81 #include <inet/ip_impl.h>
  82 #include <inet/ip6.h>
  83 #include <inet/ip_ndp.h>
  84 #include <inet/mi.h>
  85 #include <inet/mib2.h>
  86 #include <inet/nd.h>
  87 #include <inet/optcom.h>
  88 #include <inet/snmpcom.h>
  89 #include <inet/kstatcom.h>
  90 #include <inet/tcp.h>
  91 #include <inet/tcp_impl.h>
  92 #include <net/pfkeyv2.h>
  93 #include <inet/ipsec_info.h>
  94 #include <inet/ipdrop.h>
  95 #include <inet/tcp_trace.h>
  96 
  97 #include <inet/ipclassifier.h>
  98 #include <inet/ip_ire.h>
  99 #include <inet/ip_ftable.h>
 100 #include <inet/ip_if.h>
 101 #include <inet/ipp_common.h>
 102 #include <inet/ip_netinfo.h>
 103 #include <sys/squeue.h>
 104 #include <inet/kssl/ksslapi.h>
 105 #include <sys/tsol/label.h>
 106 #include <sys/tsol/tnet.h>
 107 #include <rpc/pmap_prot.h>
 108 
 109 /*
 110  * TCP Notes: aka FireEngine Phase I (PSARC 2002/433)
 111  *
 112  * (Read the detailed design doc in PSARC case directory)
 113  *
 114  * The entire tcp state is contained in tcp_t and conn_t structure
 115  * which are allocated in tandem using ipcl_conn_create() and passing
 116  * IPCL_CONNTCP as a flag. We use 'conn_ref' and 'conn_lock' to protect
 117  * the references on the tcp_t. The tcp_t structure is never compressed
 118  * and packets always land on the correct TCP perimeter from the time
 119  * eager is created till the time tcp_t dies (as such the old mentat
 120  * TCP global queue is not used for detached state and no IPSEC checking
 121  * is required). The global queue is still allocated to send out resets
 122  * for connection which have no listeners and IP directly calls
 123  * tcp_xmit_listeners_reset() which does any policy check.
 124  *
 125  * Protection and Synchronisation mechanism:
 126  *
 127  * The tcp data structure does not use any kind of lock for protecting
 128  * its state but instead uses 'squeues' for mutual exclusion from various
 129  * read and write side threads. To access a tcp member, the thread should
 130  * always be behind squeue (via squeue_enter, squeue_enter_nodrain, or
 131  * squeue_fill). Since the squeues allow a direct function call, caller
 132  * can pass any tcp function having prototype of edesc_t as argument
 133  * (different from traditional STREAMs model where packets come in only
 134  * designated entry points). The list of functions that can be directly
 135  * called via squeue are listed before the usual function prototype.
 136  *
 137  * Referencing:
 138  *
 139  * TCP is MT-Hot and we use a reference based scheme to make sure that the
 140  * tcp structure doesn't disappear when its needed. When the application
 141  * creates an outgoing connection or accepts an incoming connection, we
 142  * start out with 2 references on 'conn_ref'. One for TCP and one for IP.
 143  * The IP reference is just a symbolic reference since ip_tcpclose()
 144  * looks at tcp structure after tcp_close_output() returns which could
 145  * have dropped the last TCP reference. So as long as the connection is
 146  * in attached state i.e. !TCP_IS_DETACHED, we have 2 references on the
 147  * conn_t. The classifier puts its own reference when the connection is
 148  * inserted in listen or connected hash. Anytime a thread needs to enter
 149  * the tcp connection perimeter, it retrieves the conn/tcp from q->ptr
 150  * on write side or by doing a classify on read side and then puts a
 151  * reference on the conn before doing squeue_enter/tryenter/fill. For
 152  * read side, the classifier itself puts the reference under fanout lock
 153  * to make sure that tcp can't disappear before it gets processed. The
 154  * squeue will drop this reference automatically so the called function
 155  * doesn't have to do a DEC_REF.
 156  *
 157  * Opening a new connection:
 158  *
 159  * The outgoing connection open is pretty simple. tcp_open() does the
 160  * work in creating the conn/tcp structure and initializing it. The
 161  * squeue assignment is done based on the CPU the application
 162  * is running on. So for outbound connections, processing is always done
 163  * on application CPU which might be different from the incoming CPU
 164  * being interrupted by the NIC. An optimal way would be to figure out
 165  * the NIC <-> CPU binding at listen time, and assign the outgoing
 166  * connection to the squeue attached to the CPU that will be interrupted
 167  * for incoming packets (we know the NIC based on the bind IP address).
 168  * This might seem like a problem if more data is going out but the
 169  * fact is that in most cases the transmit is ACK driven transmit where
 170  * the outgoing data normally sits on TCP's xmit queue waiting to be
 171  * transmitted.
 172  *
 173  * Accepting a connection:
 174  *
 175  * This is a more interesting case because of various races involved in
 176  * establishing a eager in its own perimeter. Read the meta comment on
 177  * top of tcp_conn_request(). But briefly, the squeue is picked by
 178  * ip_tcp_input()/ip_fanout_tcp_v6() based on the interrupted CPU.
 179  *
 180  * Closing a connection:
 181  *
 182  * The close is fairly straight forward. tcp_close() calls tcp_close_output()
 183  * via squeue to do the close and mark the tcp as detached if the connection
 184  * was in state TCPS_ESTABLISHED or greater. In the later case, TCP keep its
 185  * reference but tcp_close() drop IP's reference always. So if tcp was
 186  * not killed, it is sitting in time_wait list with 2 reference - 1 for TCP
 187  * and 1 because it is in classifier's connected hash. This is the condition
 188  * we use to determine that its OK to clean up the tcp outside of squeue
 189  * when time wait expires (check the ref under fanout and conn_lock and
 190  * if it is 2, remove it from fanout hash and kill it).
 191  *
 192  * Although close just drops the necessary references and marks the
 193  * tcp_detached state, tcp_close needs to know the tcp_detached has been
 194  * set (under squeue) before letting the STREAM go away (because a
 195  * inbound packet might attempt to go up the STREAM while the close
 196  * has happened and tcp_detached is not set). So a special lock and
 197  * flag is used along with a condition variable (tcp_closelock, tcp_closed,
 198  * and tcp_closecv) to signal tcp_close that tcp_close_out() has marked
 199  * tcp_detached.
 200  *
 201  * Special provisions and fast paths:
 202  *
 203  * We make special provision for (AF_INET, SOCK_STREAM) sockets which
 204  * can't have 'ipv6_recvpktinfo' set and for these type of sockets, IP
 205  * will never send a M_CTL to TCP. As such, ip_tcp_input() which handles
 206  * all TCP packets from the wire makes a IPCL_IS_TCP4_CONNECTED_NO_POLICY
 207  * check to send packets directly to tcp_rput_data via squeue. Everyone
 208  * else comes through tcp_input() on the read side.
 209  *
 210  * We also make special provisions for sockfs by marking tcp_issocket
 211  * whenever we have only sockfs on top of TCP. This allows us to skip
 212  * putting the tcp in acceptor hash since a sockfs listener can never
 213  * become acceptor and also avoid allocating a tcp_t for acceptor STREAM
 214  * since eager has already been allocated and the accept now happens
 215  * on acceptor STREAM. There is a big blob of comment on top of
 216  * tcp_conn_request explaining the new accept. When socket is POP'd,
 217  * sockfs sends us an ioctl to mark the fact and we go back to old
 218  * behaviour. Once tcp_issocket is unset, its never set for the
 219  * life of that connection.
 220  *
 221  * In support of on-board asynchronous DMA hardware (e.g. Intel I/OAT)
 222  * two consoldiation private KAPIs are used to enqueue M_DATA mblk_t's
 223  * directly to the socket (sodirect) and start an asynchronous copyout
 224  * to a user-land receive-side buffer (uioa) when a blocking socket read
 225  * (e.g. read, recv, ...) is pending.
 226  *
 227  * This is accomplished when tcp_issocket is set and tcp_sodirect is not
 228  * NULL so points to an sodirect_t and if marked enabled then we enqueue
 229  * all mblk_t's directly to the socket.
 230  *
 231  * Further, if the sodirect_t sod_uioa and if marked enabled (due to a
 232  * blocking socket read, e.g. user-land read, recv, ...) then an asynchronous
 233  * copyout will be started directly to the user-land uio buffer. Also, as we
 234  * have a pending read, TCP's push logic can take into account the number of
 235  * bytes to be received and only awake the blocked read()er when the uioa_t
 236  * byte count has been satisfied.
 237  *
 238  * IPsec notes :
 239  *
 240  * Since a packet is always executed on the correct TCP perimeter
 241  * all IPsec processing is defered to IP including checking new
 242  * connections and setting IPSEC policies for new connection. The
 243  * only exception is tcp_xmit_listeners_reset() which is called
 244  * directly from IP and needs to policy check to see if TH_RST
 245  * can be sent out.
 246  *
 247  * PFHooks notes :
 248  *
 249  * For mdt case, one meta buffer contains multiple packets. Mblks for every
 250  * packet are assembled and passed to the hooks. When packets are blocked,
 251  * or boundary of any packet is changed, the mdt processing is stopped, and
 252  * packets of the meta buffer are send to the IP path one by one.
 253  */
 254 
 255 /*
 256  * Values for squeue switch:
 257  * 1: squeue_enter_nodrain
 258  * 2: squeue_enter
 259  * 3: squeue_fill
 260  */
 261 int tcp_squeue_close = 2;       /* Setable in /etc/system */
 262 int tcp_squeue_wput = 2;
 263 
 264 squeue_func_t tcp_squeue_close_proc;
 265 squeue_func_t tcp_squeue_wput_proc;
 266 
 267 /*
 268  * Macros for sodirect:
 269  *
 270  * SOD_PTR_ENTER(tcp, sodp) - for the tcp_t pointer "tcp" set the
 271  * sodirect_t pointer "sodp" to the socket/tcp shared sodirect_t
 272  * if it exists and is enabled, else to NULL. Note, in the current
 273  * sodirect implementation the sod_lock must not be held across any
 274  * STREAMS call (e.g. putnext) else a "recursive mutex_enter" PANIC
 275  * will result as sod_lock is the streamhead stdata.sd_lock.
 276  *
 277  * SOD_NOT_ENABLED(tcp) - return true if not a sodirect tcp_t or the
 278  * sodirect_t isn't enabled, usefull for ASSERT()ing that a recieve
 279  * side tcp code path dealing with a tcp_rcv_list or putnext() isn't
 280  * being used when sodirect code paths should be.
 281  */
 282 
 283 #define SOD_PTR_ENTER(tcp, sodp)                                        \
 284         (sodp) = (tcp)->tcp_sodirect;                                        \
 285                                                                         \
 286         if ((sodp) != NULL) {                                           \
 287                 mutex_enter((sodp)->sod_lock);                               \
 288                 if (!((sodp)->sod_state & SOD_ENABLED)) {                \
 289                         mutex_exit((sodp)->sod_lock);                        \
 290                         (sodp) = NULL;                                  \
 291                 }                                                       \
 292         }
 293 
 294 #define SOD_NOT_ENABLED(tcp)                                            \
 295         ((tcp)->tcp_sodirect == NULL ||                                      \
 296             !((tcp)->tcp_sodirect->sod_state & SOD_ENABLED))
 297 
 298 /*
 299  * This controls how tiny a write must be before we try to copy it
 300  * into the the mblk on the tail of the transmit queue.  Not much
 301  * speedup is observed for values larger than sixteen.  Zero will
 302  * disable the optimisation.
 303  */
 304 int tcp_tx_pull_len = 16;
 305 
 306 /*
 307  * TCP Statistics.
 308  *
 309  * How TCP statistics work.
 310  *
 311  * There are two types of statistics invoked by two macros.
 312  *
 313  * TCP_STAT(name) does non-atomic increment of a named stat counter. It is
 314  * supposed to be used in non MT-hot paths of the code.
 315  *
 316  * TCP_DBGSTAT(name) does atomic increment of a named stat counter. It is
 317  * supposed to be used for DEBUG purposes and may be used on a hot path.
 318  *
 319  * Both TCP_STAT and TCP_DBGSTAT counters are available using kstat
 320  * (use "kstat tcp" to get them).
 321  *
 322  * There is also additional debugging facility that marks tcp_clean_death()
 323  * instances and saves them in tcp_t structure. It is triggered by
 324  * TCP_TAG_CLEAN_DEATH define. Also, there is a global array of counters for
 325  * tcp_clean_death() calls that counts the number of times each tag was hit. It
 326  * is triggered by TCP_CLD_COUNTERS define.
 327  *
 328  * How to add new counters.
 329  *
 330  * 1) Add a field in the tcp_stat structure describing your counter.
 331  * 2) Add a line in the template in tcp_kstat2_init() with the name
 332  *    of the counter.
 333  *
 334  *    IMPORTANT!! - make sure that both are in sync !!
 335  * 3) Use either TCP_STAT or TCP_DBGSTAT with the name.
 336  *
 337  * Please avoid using private counters which are not kstat-exported.
 338  *
 339  * TCP_TAG_CLEAN_DEATH set to 1 enables tagging of tcp_clean_death() instances
 340  * in tcp_t structure.
 341  *
 342  * TCP_MAX_CLEAN_DEATH_TAG is the maximum number of possible clean death tags.
 343  */
 344 
 345 #ifndef TCP_DEBUG_COUNTER
 346 #ifdef DEBUG
 347 #define TCP_DEBUG_COUNTER 1
 348 #else
 349 #define TCP_DEBUG_COUNTER 0
 350 #endif
 351 #endif
 352 
 353 #define TCP_CLD_COUNTERS 0
 354 
 355 #define TCP_TAG_CLEAN_DEATH 1
 356 #define TCP_MAX_CLEAN_DEATH_TAG 32
 357 
 358 #ifdef lint
 359 static int _lint_dummy_;
 360 #endif
 361 
 362 #if TCP_CLD_COUNTERS
 363 static uint_t tcp_clean_death_stat[TCP_MAX_CLEAN_DEATH_TAG];
 364 #define TCP_CLD_STAT(x) tcp_clean_death_stat[x]++
 365 #elif defined(lint)
 366 #define TCP_CLD_STAT(x) ASSERT(_lint_dummy_ == 0);
 367 #else
 368 #define TCP_CLD_STAT(x)
 369 #endif
 370 
 371 #if TCP_DEBUG_COUNTER
 372 #define TCP_DBGSTAT(tcps, x)    \
 373         atomic_add_64(&((tcps)->tcps_statistics.x.value.ui64), 1)
 374 #define TCP_G_DBGSTAT(x)        \
 375         atomic_add_64(&(tcp_g_statistics.x.value.ui64), 1)
 376 #elif defined(lint)
 377 #define TCP_DBGSTAT(tcps, x) ASSERT(_lint_dummy_ == 0);
 378 #define TCP_G_DBGSTAT(x) ASSERT(_lint_dummy_ == 0);
 379 #else
 380 #define TCP_DBGSTAT(tcps, x)
 381 #define TCP_G_DBGSTAT(x)
 382 #endif
 383 
 384 #define TCP_G_STAT(x)   (tcp_g_statistics.x.value.ui64++)
 385 
 386 tcp_g_stat_t    tcp_g_statistics;
 387 kstat_t         *tcp_g_kstat;
 388 
 389 /*
 390  * Call either ip_output or ip_output_v6. This replaces putnext() calls on the
 391  * tcp write side.
 392  */
 393 #define CALL_IP_WPUT(connp, q, mp) {                                    \
 394         tcp_stack_t     *tcps;                                          \
 395                                                                         \
 396         tcps = connp->conn_netstack->netstack_tcp;                        \
 397         ASSERT(((q)->q_flag & QREADR) == 0);                             \
 398         TCP_DBGSTAT(tcps, tcp_ip_output);                               \
 399         connp->conn_send(connp, (mp), (q), IP_WPUT);                 \
 400 }
 401 
 402 /* Macros for timestamp comparisons */
 403 #define TSTMP_GEQ(a, b) ((int32_t)((a)-(b)) >= 0)
 404 #define TSTMP_LT(a, b)  ((int32_t)((a)-(b)) < 0)
 405 
 406 /*
 407  * Parameters for TCP Initial Send Sequence number (ISS) generation.  When
 408  * tcp_strong_iss is set to 1, which is the default, the ISS is calculated
 409  * by adding three components: a time component which grows by 1 every 4096
 410  * nanoseconds (versus every 4 microseconds suggested by RFC 793, page 27);
 411  * a per-connection component which grows by 125000 for every new connection;
 412  * and an "extra" component that grows by a random amount centered
 413  * approximately on 64000.  This causes the the ISS generator to cycle every
 414  * 4.89 hours if no TCP connections are made, and faster if connections are
 415  * made.
 416  *
 417  * When tcp_strong_iss is set to 0, ISS is calculated by adding two
 418  * components: a time component which grows by 250000 every second; and
 419  * a per-connection component which grows by 125000 for every new connections.
 420  *
 421  * A third method, when tcp_strong_iss is set to 2, for generating ISS is
 422  * prescribed by Steve Bellovin.  This involves adding time, the 125000 per
 423  * connection, and a one-way hash (MD5) of the connection ID <sport, dport,
 424  * src, dst>, a "truly" random (per RFC 1750) number, and a console-entered
 425  * password.
 426  */
 427 #define ISS_INCR        250000
 428 #define ISS_NSEC_SHT    12
 429 
 430 static sin_t    sin_null;       /* Zero address for quick clears */
 431 static sin6_t   sin6_null;      /* Zero address for quick clears */
 432 
 433 /*
 434  * This implementation follows the 4.3BSD interpretation of the urgent
 435  * pointer and not RFC 1122. Switching to RFC 1122 behavior would cause
 436  * incompatible changes in protocols like telnet and rlogin.
 437  */
 438 #define TCP_OLD_URP_INTERPRETATION      1
 439 
 440 #define TCP_IS_DETACHED_NONEAGER(tcp)   \
 441         (TCP_IS_DETACHED(tcp) && \
 442             (!(tcp)->tcp_hard_binding))
 443 
 444 /*
 445  * TCP reassembly macros.  We hide starting and ending sequence numbers in
 446  * b_next and b_prev of messages on the reassembly queue.  The messages are
 447  * chained using b_cont.  These macros are used in tcp_reass() so we don't
 448  * have to see the ugly casts and assignments.
 449  */
 450 #define TCP_REASS_SEQ(mp)               ((uint32_t)(uintptr_t)((mp)->b_next))
 451 #define TCP_REASS_SET_SEQ(mp, u)        ((mp)->b_next = \
 452                                         (mblk_t *)(uintptr_t)(u))
 453 #define TCP_REASS_END(mp)               ((uint32_t)(uintptr_t)((mp)->b_prev))
 454 #define TCP_REASS_SET_END(mp, u)        ((mp)->b_prev = \
 455                                         (mblk_t *)(uintptr_t)(u))
 456 
 457 /*
 458  * Implementation of TCP Timers.
 459  * =============================
 460  *
 461  * INTERFACE:
 462  *
 463  * There are two basic functions dealing with tcp timers:
 464  *
 465  *      timeout_id_t    tcp_timeout(connp, func, time)
 466  *      clock_t         tcp_timeout_cancel(connp, timeout_id)
 467  *      TCP_TIMER_RESTART(tcp, intvl)
 468  *
 469  * tcp_timeout() starts a timer for the 'tcp' instance arranging to call 'func'
 470  * after 'time' ticks passed. The function called by timeout() must adhere to
 471  * the same restrictions as a driver soft interrupt handler - it must not sleep
 472  * or call other functions that might sleep. The value returned is the opaque
 473  * non-zero timeout identifier that can be passed to tcp_timeout_cancel() to
 474  * cancel the request. The call to tcp_timeout() may fail in which case it
 475  * returns zero. This is different from the timeout(9F) function which never
 476  * fails.
 477  *
 478  * The call-back function 'func' always receives 'connp' as its single
 479  * argument. It is always executed in the squeue corresponding to the tcp
 480  * structure. The tcp structure is guaranteed to be present at the time the
 481  * call-back is called.
 482  *
 483  * NOTE: The call-back function 'func' is never called if tcp is in
 484  *      the TCPS_CLOSED state.
 485  *
 486  * tcp_timeout_cancel() attempts to cancel a pending tcp_timeout()
 487  * request. locks acquired by the call-back routine should not be held across
 488  * the call to tcp_timeout_cancel() or a deadlock may result.
 489  *
 490  * tcp_timeout_cancel() returns -1 if it can not cancel the timeout request.
 491  * Otherwise, it returns an integer value greater than or equal to 0. In
 492  * particular, if the call-back function is already placed on the squeue, it can
 493  * not be canceled.
 494  *
 495  * NOTE: both tcp_timeout() and tcp_timeout_cancel() should always be called
 496  *      within squeue context corresponding to the tcp instance. Since the
 497  *      call-back is also called via the same squeue, there are no race
 498  *      conditions described in untimeout(9F) manual page since all calls are
 499  *      strictly serialized.
 500  *
 501  *      TCP_TIMER_RESTART() is a macro that attempts to cancel a pending timeout
 502  *      stored in tcp_timer_tid and starts a new one using
 503  *      MSEC_TO_TICK(intvl). It always uses tcp_timer() function as a call-back
 504  *      and stores the return value of tcp_timeout() in the tcp->tcp_timer_tid
 505  *      field.
 506  *
 507  * NOTE: since the timeout cancellation is not guaranteed, the cancelled
 508  *      call-back may still be called, so it is possible tcp_timer() will be
 509  *      called several times. This should not be a problem since tcp_timer()
 510  *      should always check the tcp instance state.
 511  *
 512  *
 513  * IMPLEMENTATION:
 514  *
 515  * TCP timers are implemented using three-stage process. The call to
 516  * tcp_timeout() uses timeout(9F) function to call tcp_timer_callback() function
 517  * when the timer expires. The tcp_timer_callback() arranges the call of the
 518  * tcp_timer_handler() function via squeue corresponding to the tcp
 519  * instance. The tcp_timer_handler() calls actual requested timeout call-back
 520  * and passes tcp instance as an argument to it. Information is passed between
 521  * stages using the tcp_timer_t structure which contains the connp pointer, the
 522  * tcp call-back to call and the timeout id returned by the timeout(9F).
 523  *
 524  * The tcp_timer_t structure is not used directly, it is embedded in an mblk_t -
 525  * like structure that is used to enter an squeue. The mp->b_rptr of this pseudo
 526  * mblk points to the beginning of tcp_timer_t structure. The tcp_timeout()
 527  * returns the pointer to this mblk.
 528  *
 529  * The pseudo mblk is allocated from a special tcp_timer_cache kmem cache. It
 530  * looks like a normal mblk without actual dblk attached to it.
 531  *
 532  * To optimize performance each tcp instance holds a small cache of timer
 533  * mblocks. In the current implementation it caches up to two timer mblocks per
 534  * tcp instance. The cache is preserved over tcp frees and is only freed when
 535  * the whole tcp structure is destroyed by its kmem destructor. Since all tcp
 536  * timer processing happens on a corresponding squeue, the cache manipulation
 537  * does not require any locks. Experiments show that majority of timer mblocks
 538  * allocations are satisfied from the tcp cache and do not involve kmem calls.
 539  *
 540  * The tcp_timeout() places a refhold on the connp instance which guarantees
 541  * that it will be present at the time the call-back function fires. The
 542  * tcp_timer_handler() drops the reference after calling the call-back, so the
 543  * call-back function does not need to manipulate the references explicitly.
 544  */
 545 
 546 typedef struct tcp_timer_s {
 547         conn_t  *connp;
 548         void    (*tcpt_proc)(void *);
 549         timeout_id_t   tcpt_tid;
 550 } tcp_timer_t;
 551 
 552 static kmem_cache_t *tcp_timercache;
 553 kmem_cache_t    *tcp_sack_info_cache;
 554 kmem_cache_t    *tcp_iphc_cache;
 555 
 556 /*
 557  * For scalability, we must not run a timer for every TCP connection
 558  * in TIME_WAIT state.  To see why, consider (for time wait interval of
 559  * 4 minutes):
 560  *      1000 connections/sec * 240 seconds/time wait = 240,000 active conn's
 561  *
 562  * This list is ordered by time, so you need only delete from the head
 563  * until you get to entries which aren't old enough to delete yet.
 564  * The list consists of only the detached TIME_WAIT connections.
 565  *
 566  * Note that the timer (tcp_time_wait_expire) is started when the tcp_t
 567  * becomes detached TIME_WAIT (either by changing the state and already
 568  * being detached or the other way around). This means that the TIME_WAIT
 569  * state can be extended (up to doubled) if the connection doesn't become
 570  * detached for a long time.
 571  *
 572  * The list manipulations (including tcp_time_wait_next/prev)
 573  * are protected by the tcp_time_wait_lock. The content of the
 574  * detached TIME_WAIT connections is protected by the normal perimeters.
 575  *
 576  * This list is per squeue and squeues are shared across the tcp_stack_t's.
 577  * Things on tcp_time_wait_head remain associated with the tcp_stack_t
 578  * and conn_netstack.
 579  * The tcp_t's that are added to tcp_free_list are disassociated and
 580  * have NULL tcp_tcps and conn_netstack pointers.
 581  */
 582 typedef struct tcp_squeue_priv_s {
 583         kmutex_t        tcp_time_wait_lock;
 584         timeout_id_t    tcp_time_wait_tid;
 585         tcp_t           *tcp_time_wait_head;
 586         tcp_t           *tcp_time_wait_tail;
 587         tcp_t           *tcp_free_list;
 588         uint_t          tcp_free_list_cnt;
 589 } tcp_squeue_priv_t;
 590 
 591 /*
 592  * TCP_TIME_WAIT_DELAY governs how often the time_wait_collector runs.
 593  * Running it every 5 seconds seems to give the best results.
 594  */
 595 #define TCP_TIME_WAIT_DELAY drv_usectohz(5000000)
 596 
 597 /*
 598  * To prevent memory hog, limit the number of entries in tcp_free_list
 599  * to 1% of available memory / number of cpus
 600  */
 601 uint_t tcp_free_list_max_cnt = 0;
 602 
 603 #define TCP_XMIT_LOWATER        4096
 604 #define TCP_XMIT_HIWATER        49152
 605 #define TCP_RECV_LOWATER        2048
 606 #define TCP_RECV_HIWATER        49152
 607 
 608 /*
 609  *  PAWS needs a timer for 24 days.  This is the number of ticks in 24 days
 610  */
 611 #define PAWS_TIMEOUT    ((clock_t)(24*24*60*60*hz))
 612 
 613 #define TIDUSZ  4096    /* transport interface data unit size */
 614 
 615 /*
 616  * Bind hash list size and has function.  It has to be a power of 2 for
 617  * hashing.
 618  */
 619 #define TCP_BIND_FANOUT_SIZE    512
 620 #define TCP_BIND_HASH(lport) (ntohs(lport) & (TCP_BIND_FANOUT_SIZE - 1))
 621 /*
 622  * Size of listen and acceptor hash list.  It has to be a power of 2 for
 623  * hashing.
 624  */
 625 #define TCP_FANOUT_SIZE         256
 626 
 627 #ifdef  _ILP32
 628 #define TCP_ACCEPTOR_HASH(accid)                                        \
 629                 (((uint_t)(accid) >> 8) & (TCP_FANOUT_SIZE - 1))
 630 #else
 631 #define TCP_ACCEPTOR_HASH(accid)                                        \
 632                 ((uint_t)(accid) & (TCP_FANOUT_SIZE - 1))
 633 #endif  /* _ILP32 */
 634 
 635 #define IP_ADDR_CACHE_SIZE      2048
 636 #define IP_ADDR_CACHE_HASH(faddr)                                       \
 637         (ntohl(faddr) & (IP_ADDR_CACHE_SIZE -1))
 638 
 639 /* Hash for HSPs uses all 32 bits, since both networks and hosts are in table */
 640 #define TCP_HSP_HASH_SIZE 256
 641 
 642 #define TCP_HSP_HASH(addr)                                      \
 643         (((addr>>24) ^ (addr >>16) ^                        \
 644             (addr>>8) ^ (addr)) % TCP_HSP_HASH_SIZE)
 645 
 646 /*
 647  * TCP options struct returned from tcp_parse_options.
 648  */
 649 typedef struct tcp_opt_s {
 650         uint32_t        tcp_opt_mss;
 651         uint32_t        tcp_opt_wscale;
 652         uint32_t        tcp_opt_ts_val;
 653         uint32_t        tcp_opt_ts_ecr;
 654         tcp_t           *tcp;
 655 } tcp_opt_t;
 656 
 657 /*
 658  * RFC1323-recommended phrasing of TSTAMP option, for easier parsing
 659  */
 660 
 661 #ifdef _BIG_ENDIAN
 662 #define TCPOPT_NOP_NOP_TSTAMP ((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | \
 663         (TCPOPT_TSTAMP << 8) | 10)
 664 #else
 665 #define TCPOPT_NOP_NOP_TSTAMP ((10 << 24) | (TCPOPT_TSTAMP << 16) | \
 666         (TCPOPT_NOP << 8) | TCPOPT_NOP)
 667 #endif
 668 
 669 /*
 670  * Flags returned from tcp_parse_options.
 671  */
 672 #define TCP_OPT_MSS_PRESENT     1
 673 #define TCP_OPT_WSCALE_PRESENT  2
 674 #define TCP_OPT_TSTAMP_PRESENT  4
 675 #define TCP_OPT_SACK_OK_PRESENT 8
 676 #define TCP_OPT_SACK_PRESENT    16
 677 
 678 /* TCP option length */
 679 #define TCPOPT_NOP_LEN          1
 680 #define TCPOPT_MAXSEG_LEN       4
 681 #define TCPOPT_WS_LEN           3
 682 #define TCPOPT_REAL_WS_LEN      (TCPOPT_WS_LEN+1)
 683 #define TCPOPT_TSTAMP_LEN       10
 684 #define TCPOPT_REAL_TS_LEN      (TCPOPT_TSTAMP_LEN+2)
 685 #define TCPOPT_SACK_OK_LEN      2
 686 #define TCPOPT_REAL_SACK_OK_LEN (TCPOPT_SACK_OK_LEN+2)
 687 #define TCPOPT_REAL_SACK_LEN    4
 688 #define TCPOPT_MAX_SACK_LEN     36
 689 #define TCPOPT_HEADER_LEN       2
 690 
 691 /* TCP cwnd burst factor. */
 692 #define TCP_CWND_INFINITE       65535
 693 #define TCP_CWND_SS             3
 694 #define TCP_CWND_NORMAL         5
 695 
 696 /* Maximum TCP initial cwin (start/restart). */
 697 #define TCP_MAX_INIT_CWND       8
 698 
 699 /*
 700  * Initialize cwnd according to RFC 3390.  def_max_init_cwnd is
 701  * either tcp_slow_start_initial or tcp_slow_start_after idle
 702  * depending on the caller.  If the upper layer has not used the
 703  * TCP_INIT_CWND option to change the initial cwnd, tcp_init_cwnd
 704  * should be 0 and we use the formula in RFC 3390 to set tcp_cwnd.
 705  * If the upper layer has changed set the tcp_init_cwnd, just use
 706  * it to calculate the tcp_cwnd.
 707  */
 708 #define SET_TCP_INIT_CWND(tcp, mss, def_max_init_cwnd)                  \
 709 {                                                                       \
 710         if ((tcp)->tcp_init_cwnd == 0) {                             \
 711                 (tcp)->tcp_cwnd = MIN(def_max_init_cwnd * (mss),     \
 712                     MIN(4 * (mss), MAX(2 * (mss), 4380 / (mss) * (mss)))); \
 713         } else {                                                        \
 714                 (tcp)->tcp_cwnd = (tcp)->tcp_init_cwnd * (mss);           \
 715         }                                                               \
 716         tcp->tcp_cwnd_cnt = 0;                                               \
 717 }
 718 
 719 /* TCP Timer control structure */
 720 typedef struct tcpt_s {
 721         pfv_t   tcpt_pfv;       /* The routine we are to call */
 722         tcp_t   *tcpt_tcp;      /* The parameter we are to pass in */
 723 } tcpt_t;
 724 
 725 /* Host Specific Parameter structure */
 726 typedef struct tcp_hsp {
 727         struct tcp_hsp  *tcp_hsp_next;
 728         in6_addr_t      tcp_hsp_addr_v6;
 729         in6_addr_t      tcp_hsp_subnet_v6;
 730         uint_t          tcp_hsp_vers;   /* IPV4_VERSION | IPV6_VERSION */
 731         int32_t         tcp_hsp_sendspace;
 732         int32_t         tcp_hsp_recvspace;
 733         int32_t         tcp_hsp_tstamp;
 734 } tcp_hsp_t;
 735 #define tcp_hsp_addr    V4_PART_OF_V6(tcp_hsp_addr_v6)
 736 #define tcp_hsp_subnet  V4_PART_OF_V6(tcp_hsp_subnet_v6)
 737 
 738 /*
 739  * Functions called directly via squeue having a prototype of edesc_t.
 740  */
 741 void            tcp_conn_request(void *arg, mblk_t *mp, void *arg2);
 742 static void     tcp_wput_nondata(void *arg, mblk_t *mp, void *arg2);
 743 void            tcp_accept_finish(void *arg, mblk_t *mp, void *arg2);
 744 static void     tcp_wput_ioctl(void *arg, mblk_t *mp, void *arg2);
 745 static void     tcp_wput_proto(void *arg, mblk_t *mp, void *arg2);
 746 void            tcp_input(void *arg, mblk_t *mp, void *arg2);
 747 void            tcp_rput_data(void *arg, mblk_t *mp, void *arg2);
 748 static void     tcp_close_output(void *arg, mblk_t *mp, void *arg2);
 749 void            tcp_output(void *arg, mblk_t *mp, void *arg2);
 750 static void     tcp_rsrv_input(void *arg, mblk_t *mp, void *arg2);
 751 static void     tcp_timer_handler(void *arg, mblk_t *mp, void *arg2);
 752 static void     tcp_linger_interrupted(void *arg, mblk_t *mp, void *arg2);
 753 
 754 
 755 /* Prototype for TCP functions */
 756 static void     tcp_random_init(void);
 757 int             tcp_random(void);
 758 static void     tcp_accept(tcp_t *tcp, mblk_t *mp);
 759 static void     tcp_accept_swap(tcp_t *listener, tcp_t *acceptor,
 760                     tcp_t *eager);
 761 static int      tcp_adapt_ire(tcp_t *tcp, mblk_t *ire_mp);
 762 static in_port_t tcp_bindi(tcp_t *tcp, in_port_t port, const in6_addr_t *laddr,
 763     int reuseaddr, boolean_t quick_connect, boolean_t bind_to_req_port_only,
 764     boolean_t user_specified);
 765 static void     tcp_closei_local(tcp_t *tcp);
 766 static void     tcp_close_detached(tcp_t *tcp);
 767 static boolean_t tcp_conn_con(tcp_t *tcp, uchar_t *iphdr, tcph_t *tcph,
 768                         mblk_t *idmp, mblk_t **defermp);
 769 static void     tcp_connect(tcp_t *tcp, mblk_t *mp);
 770 static void     tcp_connect_ipv4(tcp_t *tcp, mblk_t *mp, ipaddr_t *dstaddrp,
 771                     in_port_t dstport, uint_t srcid);
 772 static void     tcp_connect_ipv6(tcp_t *tcp, mblk_t *mp, in6_addr_t *dstaddrp,
 773                     in_port_t dstport, uint32_t flowinfo, uint_t srcid,
 774                     uint32_t scope_id);
 775 static int      tcp_clean_death(tcp_t *tcp, int err, uint8_t tag);
 776 static void     tcp_def_q_set(tcp_t *tcp, mblk_t *mp);
 777 static void     tcp_disconnect(tcp_t *tcp, mblk_t *mp);
 778 static char     *tcp_display(tcp_t *tcp, char *, char);
 779 static boolean_t tcp_eager_blowoff(tcp_t *listener, t_scalar_t seqnum);
 780 static void     tcp_eager_cleanup(tcp_t *listener, boolean_t q0_only);
 781 static void     tcp_eager_unlink(tcp_t *tcp);
 782 static void     tcp_err_ack(tcp_t *tcp, mblk_t *mp, int tlierr,
 783                     int unixerr);
 784 static void     tcp_err_ack_prim(tcp_t *tcp, mblk_t *mp, int primitive,
 785                     int tlierr, int unixerr);
 786 static int      tcp_extra_priv_ports_get(queue_t *q, mblk_t *mp, caddr_t cp,
 787                     cred_t *cr);
 788 static int      tcp_extra_priv_ports_add(queue_t *q, mblk_t *mp,
 789                     char *value, caddr_t cp, cred_t *cr);
 790 static int      tcp_extra_priv_ports_del(queue_t *q, mblk_t *mp,
 791                     char *value, caddr_t cp, cred_t *cr);
 792 static int      tcp_tpistate(tcp_t *tcp);
 793 static void     tcp_bind_hash_insert(tf_t *tf, tcp_t *tcp,
 794     int caller_holds_lock);
 795 static void     tcp_bind_hash_remove(tcp_t *tcp);
 796 static tcp_t    *tcp_acceptor_hash_lookup(t_uscalar_t id, tcp_stack_t *);
 797 void            tcp_acceptor_hash_insert(t_uscalar_t id, tcp_t *tcp);
 798 static void     tcp_acceptor_hash_remove(tcp_t *tcp);
 799 static void     tcp_capability_req(tcp_t *tcp, mblk_t *mp);
 800 static void     tcp_info_req(tcp_t *tcp, mblk_t *mp);
 801 static void     tcp_addr_req(tcp_t *tcp, mblk_t *mp);
 802 static void     tcp_addr_req_ipv6(tcp_t *tcp, mblk_t *mp);
 803 void            tcp_g_q_setup(tcp_stack_t *);
 804 void            tcp_g_q_create(tcp_stack_t *);
 805 void            tcp_g_q_destroy(tcp_stack_t *);
 806 static int      tcp_header_init_ipv4(tcp_t *tcp);
 807 static int      tcp_header_init_ipv6(tcp_t *tcp);
 808 int             tcp_init(tcp_t *tcp, queue_t *q);
 809 static int      tcp_init_values(tcp_t *tcp);
 810 static mblk_t   *tcp_ip_advise_mblk(void *addr, int addr_len, ipic_t **ipic);
 811 static mblk_t   *tcp_ip_bind_mp(tcp_t *tcp, t_scalar_t bind_prim,
 812                     t_scalar_t addr_length);
 813 static void     tcp_ip_ire_mark_advice(tcp_t *tcp);
 814 static void     tcp_ip_notify(tcp_t *tcp);
 815 static mblk_t   *tcp_ire_mp(mblk_t *mp);
 816 static void     tcp_iss_init(tcp_t *tcp);
 817 static void     tcp_keepalive_killer(void *arg);
 818 static int      tcp_parse_options(tcph_t *tcph, tcp_opt_t *tcpopt);
 819 static void     tcp_mss_set(tcp_t *tcp, uint32_t size, boolean_t do_ss);
 820 static int      tcp_conprim_opt_process(tcp_t *tcp, mblk_t *mp,
 821                     int *do_disconnectp, int *t_errorp, int *sys_errorp);
 822 static boolean_t tcp_allow_connopt_set(int level, int name);
 823 int             tcp_opt_default(queue_t *q, int level, int name, uchar_t *ptr);
 824 int             tcp_opt_get(queue_t *q, int level, int name, uchar_t *ptr);
 825 int             tcp_opt_set(queue_t *q, uint_t optset_context, int level,
 826                     int name, uint_t inlen, uchar_t *invalp, uint_t *outlenp,
 827                     uchar_t *outvalp, void *thisdg_attrs, cred_t *cr,
 828                     mblk_t *mblk);
 829 static void     tcp_opt_reverse(tcp_t *tcp, ipha_t *ipha);
 830 static int      tcp_opt_set_header(tcp_t *tcp, boolean_t checkonly,
 831                     uchar_t *ptr, uint_t len);
 832 static int      tcp_param_get(queue_t *q, mblk_t *mp, caddr_t cp, cred_t *cr);
 833 static boolean_t tcp_param_register(IDP *ndp, tcpparam_t *tcppa, int cnt,
 834     tcp_stack_t *);
 835 static int      tcp_param_set(queue_t *q, mblk_t *mp, char *value,
 836                     caddr_t cp, cred_t *cr);
 837 static int      tcp_param_set_aligned(queue_t *q, mblk_t *mp, char *value,
 838                     caddr_t cp, cred_t *cr);
 839 static void     tcp_iss_key_init(uint8_t *phrase, int len, tcp_stack_t *);
 840 static int      tcp_1948_phrase_set(queue_t *q, mblk_t *mp, char *value,
 841                     caddr_t cp, cred_t *cr);
 842 static void     tcp_process_shrunk_swnd(tcp_t *tcp, uint32_t shrunk_cnt);
 843 static mblk_t   *tcp_reass(tcp_t *tcp, mblk_t *mp, uint32_t start);
 844 static void     tcp_reass_elim_overlap(tcp_t *tcp, mblk_t *mp);
 845 static void     tcp_reinit(tcp_t *tcp);
 846 static void     tcp_reinit_values(tcp_t *tcp);
 847 static void     tcp_report_item(mblk_t *mp, tcp_t *tcp, int hashval,
 848                     tcp_t *thisstream, cred_t *cr);
 849 
 850 static uint_t   tcp_rcv_drain(queue_t *q, tcp_t *tcp);
 851 static void     tcp_sack_rxmit(tcp_t *tcp, uint_t *flags);
 852 static boolean_t tcp_send_rst_chk(tcp_stack_t *);
 853 static void     tcp_ss_rexmit(tcp_t *tcp);
 854 static mblk_t   *tcp_rput_add_ancillary(tcp_t *tcp, mblk_t *mp, ip6_pkt_t *ipp);
 855 static void     tcp_process_options(tcp_t *, tcph_t *);
 856 static void     tcp_rput_common(tcp_t *tcp, mblk_t *mp);
 857 static void     tcp_rsrv(queue_t *q);
 858 static int      tcp_rwnd_set(tcp_t *tcp, uint32_t rwnd);
 859 static int      tcp_snmp_state(tcp_t *tcp);
 860 static int      tcp_status_report(queue_t *q, mblk_t *mp, caddr_t cp,
 861                     cred_t *cr);
 862 static int      tcp_bind_hash_report(queue_t *q, mblk_t *mp, caddr_t cp,
 863                     cred_t *cr);
 864 static int      tcp_listen_hash_report(queue_t *q, mblk_t *mp, caddr_t cp,
 865                     cred_t *cr);
 866 static int      tcp_conn_hash_report(queue_t *q, mblk_t *mp, caddr_t cp,
 867                     cred_t *cr);
 868 static int      tcp_acceptor_hash_report(queue_t *q, mblk_t *mp, caddr_t cp,
 869                     cred_t *cr);
 870 static int      tcp_host_param_set(queue_t *q, mblk_t *mp, char *value,
 871                     caddr_t cp, cred_t *cr);
 872 static int      tcp_host_param_set_ipv6(queue_t *q, mblk_t *mp, char *value,
 873                     caddr_t cp, cred_t *cr);
 874 static int      tcp_host_param_report(queue_t *q, mblk_t *mp, caddr_t cp,
 875                     cred_t *cr);
 876 static void     tcp_timer(void *arg);
 877 static void     tcp_timer_callback(void *);
 878 static in_port_t tcp_update_next_port(in_port_t port, const tcp_t *tcp,
 879     boolean_t random);
 880 static in_port_t tcp_get_next_priv_port(const tcp_t *);
 881 static void     tcp_wput_sock(queue_t *q, mblk_t *mp);
 882 void            tcp_wput_accept(queue_t *q, mblk_t *mp);
 883 static void     tcp_wput_data(tcp_t *tcp, mblk_t *mp, boolean_t urgent);
 884 static void     tcp_wput_flush(tcp_t *tcp, mblk_t *mp);
 885 static void     tcp_wput_iocdata(tcp_t *tcp, mblk_t *mp);
 886 static int      tcp_send(queue_t *q, tcp_t *tcp, const int mss,
 887                     const int tcp_hdr_len, const int tcp_tcp_hdr_len,
 888                     const int num_sack_blk, int *usable, uint_t *snxt,
 889                     int *tail_unsent, mblk_t **xmit_tail, mblk_t *local_time,
 890                     const int mdt_thres);
 891 static int      tcp_multisend(queue_t *q, tcp_t *tcp, const int mss,
 892                     const int tcp_hdr_len, const int tcp_tcp_hdr_len,
 893                     const int num_sack_blk, int *usable, uint_t *snxt,
 894                     int *tail_unsent, mblk_t **xmit_tail, mblk_t *local_time,
 895                     const int mdt_thres);
 896 static void     tcp_fill_header(tcp_t *tcp, uchar_t *rptr, clock_t now,
 897                     int num_sack_blk);
 898 static void     tcp_wsrv(queue_t *q);
 899 static int      tcp_xmit_end(tcp_t *tcp);
 900 static void     tcp_ack_timer(void *arg);
 901 static mblk_t   *tcp_ack_mp(tcp_t *tcp);
 902 static void     tcp_xmit_early_reset(char *str, mblk_t *mp,
 903                     uint32_t seq, uint32_t ack, int ctl, uint_t ip_hdr_len,
 904                     zoneid_t zoneid, tcp_stack_t *, conn_t *connp);
 905 static void     tcp_xmit_ctl(char *str, tcp_t *tcp, uint32_t seq,
 906                     uint32_t ack, int ctl);
 907 static tcp_hsp_t *tcp_hsp_lookup(ipaddr_t addr, tcp_stack_t *);
 908 static tcp_hsp_t *tcp_hsp_lookup_ipv6(in6_addr_t *addr, tcp_stack_t *);
 909 static int      setmaxps(queue_t *q, int maxpsz);
 910 static void     tcp_set_rto(tcp_t *, time_t);
 911 static boolean_t tcp_check_policy(tcp_t *, mblk_t *, ipha_t *, ip6_t *,
 912                     boolean_t, boolean_t);
 913 static void     tcp_icmp_error_ipv6(tcp_t *tcp, mblk_t *mp,
 914                     boolean_t ipsec_mctl);
 915 static mblk_t   *tcp_setsockopt_mp(int level, int cmd,
 916                     char *opt, int optlen);
 917 static int      tcp_build_hdrs(queue_t *, tcp_t *);
 918 static void     tcp_time_wait_processing(tcp_t *tcp, mblk_t *mp,
 919                     uint32_t seg_seq, uint32_t seg_ack, int seg_len,
 920                     tcph_t *tcph);
 921 boolean_t       tcp_paws_check(tcp_t *tcp, tcph_t *tcph, tcp_opt_t *tcpoptp);
 922 boolean_t       tcp_reserved_port_add(int, in_port_t *, in_port_t *);
 923 boolean_t       tcp_reserved_port_del(in_port_t, in_port_t);
 924 boolean_t       tcp_reserved_port_check(in_port_t, tcp_stack_t *);
 925 static tcp_t    *tcp_alloc_temp_tcp(in_port_t, tcp_stack_t *);
 926 static int      tcp_reserved_port_list(queue_t *, mblk_t *, caddr_t, cred_t *);
 927 static mblk_t   *tcp_mdt_info_mp(mblk_t *);
 928 static void     tcp_mdt_update(tcp_t *, ill_mdt_capab_t *, boolean_t);
 929 static int      tcp_mdt_add_attrs(multidata_t *, const mblk_t *,
 930                     const boolean_t, const uint32_t, const uint32_t,
 931                     const uint32_t, const uint32_t, tcp_stack_t *);
 932 static void     tcp_multisend_data(tcp_t *, ire_t *, const ill_t *, mblk_t *,
 933                     const uint_t, const uint_t, boolean_t *);
 934 static mblk_t   *tcp_lso_info_mp(mblk_t *);
 935 static void     tcp_lso_update(tcp_t *, ill_lso_capab_t *);
 936 static void     tcp_send_data(tcp_t *, queue_t *, mblk_t *);
 937 extern mblk_t   *tcp_timermp_alloc(int);
 938 extern void     tcp_timermp_free(tcp_t *);
 939 static void     tcp_timer_free(tcp_t *tcp, mblk_t *mp);
 940 static void     tcp_stop_lingering(tcp_t *tcp);
 941 static void     tcp_close_linger_timeout(void *arg);
 942 static void     *tcp_stack_init(netstackid_t stackid, netstack_t *ns);
 943 static void     tcp_stack_shutdown(netstackid_t stackid, void *arg);
 944 static void     tcp_stack_fini(netstackid_t stackid, void *arg);
 945 static void     *tcp_g_kstat_init(tcp_g_stat_t *);
 946 static void     tcp_g_kstat_fini(kstat_t *);
 947 static void     *tcp_kstat_init(netstackid_t, tcp_stack_t *);
 948 static void     tcp_kstat_fini(netstackid_t, kstat_t *);
 949 static void     *tcp_kstat2_init(netstackid_t, tcp_stat_t *);
 950 static void     tcp_kstat2_fini(netstackid_t, kstat_t *);
 951 static int      tcp_kstat_update(kstat_t *kp, int rw);
 952 void            tcp_reinput(conn_t *connp, mblk_t *mp, squeue_t *sqp);
 953 static int      tcp_conn_create_v6(conn_t *lconnp, conn_t *connp, mblk_t *mp,
 954                         tcph_t *tcph, uint_t ipvers, mblk_t *idmp);
 955 static int      tcp_conn_create_v4(conn_t *lconnp, conn_t *connp, ipha_t *ipha,
 956                         tcph_t *tcph, mblk_t *idmp);
 957 static squeue_func_t tcp_squeue_switch(int);
 958 
 959 static int      tcp_open(queue_t *, dev_t *, int, int, cred_t *, boolean_t);
 960 static int      tcp_openv4(queue_t *, dev_t *, int, int, cred_t *);
 961 static int      tcp_openv6(queue_t *, dev_t *, int, int, cred_t *);
 962 static int      tcp_close(queue_t *, int);
 963 static int      tcpclose_accept(queue_t *);
 964 
 965 static void     tcp_squeue_add(squeue_t *);
 966 static boolean_t tcp_zcopy_check(tcp_t *);
 967 static void     tcp_zcopy_notify(tcp_t *);
 968 static mblk_t   *tcp_zcopy_disable(tcp_t *, mblk_t *);
 969 static mblk_t   *tcp_zcopy_backoff(tcp_t *, mblk_t *, int);
 970 static void     tcp_ire_ill_check(tcp_t *, ire_t *, ill_t *, boolean_t);
 971 
 972 extern void     tcp_kssl_input(tcp_t *, mblk_t *);
 973 
 974 void tcp_eager_kill(void *arg, mblk_t *mp, void *arg2);
 975 void tcp_clean_death_wrapper(void *arg, mblk_t *mp, void *arg2);
 976 
 977 /*
 978  * Routines related to the TCP_IOC_ABORT_CONN ioctl command.
 979  *
 980  * TCP_IOC_ABORT_CONN is a non-transparent ioctl command used for aborting
 981  * TCP connections. To invoke this ioctl, a tcp_ioc_abort_conn_t structure
 982  * (defined in tcp.h) needs to be filled in and passed into the kernel
 983  * via an I_STR ioctl command (see streamio(7I)). The tcp_ioc_abort_conn_t
 984  * structure contains the four-tuple of a TCP connection and a range of TCP
 985  * states (specified by ac_start and ac_end). The use of wildcard addresses
 986  * and ports is allowed. Connections with a matching four tuple and a state
 987  * within the specified range will be aborted. The valid states for the
 988  * ac_start and ac_end fields are in the range TCPS_SYN_SENT to TCPS_TIME_WAIT,
 989  * inclusive.
 990  *
 991  * An application which has its connection aborted by this ioctl will receive
 992  * an error that is dependent on the connection state at the time of the abort.
 993  * If the connection state is < TCPS_TIME_WAIT, an application should behave as
 994  * though a RST packet has been received.  If the connection state is equal to
 995  * TCPS_TIME_WAIT, the 2MSL timeout will immediately be canceled by the kernel
 996  * and all resources associated with the connection will be freed.
 997  */
 998 static mblk_t   *tcp_ioctl_abort_build_msg(tcp_ioc_abort_conn_t *, tcp_t *);
 999 static void     tcp_ioctl_abort_dump(tcp_ioc_abort_conn_t *);
1000 static void     tcp_ioctl_abort_handler(tcp_t *, mblk_t *);
1001 static int      tcp_ioctl_abort(tcp_ioc_abort_conn_t *, tcp_stack_t *tcps);
1002 static void     tcp_ioctl_abort_conn(queue_t *, mblk_t *);
1003 static int      tcp_ioctl_abort_bucket(tcp_ioc_abort_conn_t *, int, int *,
1004     boolean_t, tcp_stack_t *);
1005 
1006 static struct module_info tcp_rinfo =  {
1007         TCP_MOD_ID, TCP_MOD_NAME, 0, INFPSZ, TCP_RECV_HIWATER, TCP_RECV_LOWATER
1008 };
1009 
1010 static struct module_info tcp_winfo =  {
1011         TCP_MOD_ID, TCP_MOD_NAME, 0, INFPSZ, 127, 16
1012 };
1013 
1014 /*
1015  * Entry points for TCP as a device. The normal case which supports
1016  * the TCP functionality.
1017  * We have separate open functions for the /dev/tcp and /dev/tcp6 devices.
1018  */
1019 struct qinit tcp_rinitv4 = {
1020         NULL, (pfi_t)tcp_rsrv, tcp_openv4, tcp_close, NULL, &tcp_rinfo
1021 };
1022 
1023 struct qinit tcp_rinitv6 = {
1024         NULL, (pfi_t)tcp_rsrv, tcp_openv6, tcp_close, NULL, &tcp_rinfo
1025 };
1026 
1027 struct qinit tcp_winit = {
1028         (pfi_t)tcp_wput, (pfi_t)tcp_wsrv, NULL, NULL, NULL, &tcp_winfo
1029 };
1030 
1031 /* Initial entry point for TCP in socket mode. */
1032 struct qinit tcp_sock_winit = {
1033         (pfi_t)tcp_wput_sock, (pfi_t)tcp_wsrv, NULL, NULL, NULL, &tcp_winfo
1034 };
1035 
1036 /*
1037  * Entry points for TCP as a acceptor STREAM opened by sockfs when doing
1038  * an accept. Avoid allocating data structures since eager has already
1039  * been created.
1040  */
1041 struct qinit tcp_acceptor_rinit = {
1042         NULL, (pfi_t)tcp_rsrv, NULL, tcpclose_accept, NULL, &tcp_winfo
1043 };
1044 
1045 struct qinit tcp_acceptor_winit = {
1046         (pfi_t)tcp_wput_accept, NULL, NULL, NULL, NULL, &tcp_winfo
1047 };
1048 
1049 /*
1050  * Entry points for TCP loopback (read side only)
1051  * The open routine is only used for reopens, thus no need to
1052  * have a separate one for tcp_openv6.
1053  */
1054 struct qinit tcp_loopback_rinit = {
1055         (pfi_t)0, (pfi_t)tcp_rsrv, tcp_openv4, tcp_close, (pfi_t)0,
1056         &tcp_rinfo, NULL, tcp_fuse_rrw, tcp_fuse_rinfop, STRUIOT_STANDARD
1057 };
1058 
1059 /* For AF_INET aka /dev/tcp */
1060 struct streamtab tcpinfov4 = {
1061         &tcp_rinitv4, &tcp_winit
1062 };
1063 
1064 /* For AF_INET6 aka /dev/tcp6 */
1065 struct streamtab tcpinfov6 = {
1066         &tcp_rinitv6, &tcp_winit
1067 };
1068 
1069 /*
1070  * Have to ensure that tcp_g_q_close is not done by an
1071  * interrupt thread.
1072  */
1073 static taskq_t *tcp_taskq;
1074 
1075 /*
1076  * TCP has a private interface for other kernel modules to reserve a
1077  * port range for them to use.  Once reserved, TCP will not use any ports
1078  * in the range.  This interface relies on the TCP_EXCLBIND feature.  If
1079  * the semantics of TCP_EXCLBIND is changed, implementation of this interface
1080  * has to be verified.
1081  *
1082  * There can be TCP_RESERVED_PORTS_ARRAY_MAX_SIZE port ranges.  Each port
1083  * range can cover at most TCP_RESERVED_PORTS_RANGE_MAX ports.  A port
1084  * range is [port a, port b] inclusive.  And each port range is between
1085  * TCP_LOWESET_RESERVED_PORT and TCP_LARGEST_RESERVED_PORT inclusive.
1086  *
1087  * Note that the default anonymous port range starts from 32768.  There is
1088  * no port "collision" between that and the reserved port range.  If there
1089  * is port collision (because the default smallest anonymous port is lowered
1090  * or some apps specifically bind to ports in the reserved port range), the
1091  * system may not be able to reserve a port range even there are enough
1092  * unbound ports as a reserved port range contains consecutive ports .
1093  */
1094 #define TCP_RESERVED_PORTS_ARRAY_MAX_SIZE       5
1095 #define TCP_RESERVED_PORTS_RANGE_MAX            1000
1096 #define TCP_SMALLEST_RESERVED_PORT              10240
1097 #define TCP_LARGEST_RESERVED_PORT               20480
1098 
1099 /* Structure to represent those reserved port ranges. */
1100 typedef struct tcp_rport_s {
1101         in_port_t       lo_port;
1102         in_port_t       hi_port;
1103         tcp_t           **temp_tcp_array;
1104 } tcp_rport_t;
1105 
1106 /* Setable only in /etc/system. Move to ndd? */
1107 boolean_t tcp_icmp_source_quench = B_FALSE;
1108 
1109 /*
1110  * Following assumes TPI alignment requirements stay along 32 bit
1111  * boundaries
1112  */
1113 #define ROUNDUP32(x) \
1114         (((x) + (sizeof (int32_t) - 1)) & ~(sizeof (int32_t) - 1))
1115 
1116 /* Template for response to info request. */
1117 static struct T_info_ack tcp_g_t_info_ack = {
1118         T_INFO_ACK,             /* PRIM_type */
1119         0,                      /* TSDU_size */
1120         T_INFINITE,             /* ETSDU_size */
1121         T_INVALID,              /* CDATA_size */
1122         T_INVALID,              /* DDATA_size */
1123         sizeof (sin_t),         /* ADDR_size */
1124         0,                      /* OPT_size - not initialized here */
1125         TIDUSZ,                 /* TIDU_size */
1126         T_COTS_ORD,             /* SERV_type */
1127         TCPS_IDLE,              /* CURRENT_state */
1128         (XPG4_1|EXPINLINE)      /* PROVIDER_flag */
1129 };
1130 
1131 static struct T_info_ack tcp_g_t_info_ack_v6 = {
1132         T_INFO_ACK,             /* PRIM_type */
1133         0,                      /* TSDU_size */
1134         T_INFINITE,             /* ETSDU_size */
1135         T_INVALID,              /* CDATA_size */
1136         T_INVALID,              /* DDATA_size */
1137         sizeof (sin6_t),        /* ADDR_size */
1138         0,                      /* OPT_size - not initialized here */
1139         TIDUSZ,         /* TIDU_size */
1140         T_COTS_ORD,             /* SERV_type */
1141         TCPS_IDLE,              /* CURRENT_state */
1142         (XPG4_1|EXPINLINE)      /* PROVIDER_flag */
1143 };
1144 
1145 #define MS      1L
1146 #define SECONDS (1000 * MS)
1147 #define MINUTES (60 * SECONDS)
1148 #define HOURS   (60 * MINUTES)
1149 #define DAYS    (24 * HOURS)
1150 
1151 #define PARAM_MAX (~(uint32_t)0)
1152 
1153 /* Max size IP datagram is 64k - 1 */
1154 #define TCP_MSS_MAX_IPV4 (IP_MAXPACKET - (sizeof (ipha_t) + sizeof (tcph_t)))
1155 #define TCP_MSS_MAX_IPV6 (IP_MAXPACKET - (sizeof (ip6_t) + sizeof (tcph_t)))
1156 /* Max of the above */
1157 #define TCP_MSS_MAX     TCP_MSS_MAX_IPV4
1158 
1159 /* Largest TCP port number */
1160 #define TCP_MAX_PORT    (64 * 1024 - 1)
1161 
1162 /*
1163  * tcp_wroff_xtra is the extra space in front of TCP/IP header for link
1164  * layer header.  It has to be a multiple of 4.
1165  */
1166 static tcpparam_t lcl_tcp_wroff_xtra_param = { 0, 256, 32, "tcp_wroff_xtra" };
1167 #define tcps_wroff_xtra tcps_wroff_xtra_param->tcp_param_val
1168 
1169 /*
1170  * All of these are alterable, within the min/max values given, at run time.
1171  * Note that the default value of "tcp_time_wait_interval" is four minutes,
1172  * per the TCP spec.
1173  */
1174 /* BEGIN CSTYLED */
1175 static tcpparam_t       lcl_tcp_param_arr[] = {
1176  /*min          max             value           name */
1177  { 1*SECONDS,   10*MINUTES,     1*MINUTES,      "tcp_time_wait_interval"},
1178  { 1,           PARAM_MAX,      128,            "tcp_conn_req_max_q" },
1179  { 0,           PARAM_MAX,      1024,           "tcp_conn_req_max_q0" },
1180  { 1,           1024,           1,              "tcp_conn_req_min" },
1181  { 0*MS,        20*SECONDS,     0*MS,           "tcp_conn_grace_period" },
1182  { 128,         (1<<30),  1024*1024,      "tcp_cwnd_max" },
1183  { 0,           10,             0,              "tcp_debug" },
1184  { 1024,        (32*1024),      1024,           "tcp_smallest_nonpriv_port"},
1185  { 1*SECONDS,   PARAM_MAX,      3*MINUTES,      "tcp_ip_abort_cinterval"},
1186  { 1*SECONDS,   PARAM_MAX,      3*MINUTES,      "tcp_ip_abort_linterval"},
1187  { 500*MS,      PARAM_MAX,      8*MINUTES,      "tcp_ip_abort_interval"},
1188  { 1*SECONDS,   PARAM_MAX,      10*SECONDS,     "tcp_ip_notify_cinterval"},
1189  { 500*MS,      PARAM_MAX,      10*SECONDS,     "tcp_ip_notify_interval"},
1190  { 1,           255,            64,             "tcp_ipv4_ttl"},
1191  { 10*SECONDS,  10*DAYS,        2*HOURS,        "tcp_keepalive_interval"},
1192  { 0,           100,            10,             "tcp_maxpsz_multiplier" },
1193  { 1,           TCP_MSS_MAX_IPV4, 536,          "tcp_mss_def_ipv4"},
1194  { 1,           TCP_MSS_MAX_IPV4, TCP_MSS_MAX_IPV4, "tcp_mss_max_ipv4"},
1195  { 1,           TCP_MSS_MAX,    108,            "tcp_mss_min"},
1196  { 1,           (64*1024)-1,    (4*1024)-1,     "tcp_naglim_def"},
1197  { 1*MS,        20*SECONDS,     3*SECONDS,      "tcp_rexmit_interval_initial"},
1198  { 1*MS,        2*HOURS,        60*SECONDS,     "tcp_rexmit_interval_max"},
1199  { 1*MS,        2*HOURS,        400*MS,         "tcp_rexmit_interval_min"},
1200  { 1*MS,        1*MINUTES,      100*MS,         "tcp_deferred_ack_interval" },
1201  { 0,           16,             0,              "tcp_snd_lowat_fraction" },
1202  { 0,           128000,         0,              "tcp_sth_rcv_hiwat" },
1203  { 0,           128000,         0,              "tcp_sth_rcv_lowat" },
1204  { 1,           10000,          3,              "tcp_dupack_fast_retransmit" },
1205  { 0,           1,              0,              "tcp_ignore_path_mtu" },
1206  { 1024,        TCP_MAX_PORT,   32*1024,        "tcp_smallest_anon_port"},
1207  { 1024,        TCP_MAX_PORT,   TCP_MAX_PORT,   "tcp_largest_anon_port"},
1208  { TCP_XMIT_LOWATER, (1<<30), TCP_XMIT_HIWATER,"tcp_xmit_hiwat"},
1209  { TCP_XMIT_LOWATER, (1<<30), TCP_XMIT_LOWATER,"tcp_xmit_lowat"},
1210  { TCP_RECV_LOWATER, (1<<30), TCP_RECV_HIWATER,"tcp_recv_hiwat"},
1211  { 1,           65536,          4,              "tcp_recv_hiwat_minmss"},
1212  { 1*SECONDS,   PARAM_MAX,      675*SECONDS,    "tcp_fin_wait_2_flush_interval"},
1213  { 0,           TCP_MSS_MAX,    64,             "tcp_co_min"},
1214  { 8192,        (1<<30),  1024*1024,      "tcp_max_buf"},
1215 /*
1216  * Question:  What default value should I set for tcp_strong_iss?
1217  */
1218  { 0,           2,              1,              "tcp_strong_iss"},
1219  { 0,           65536,          20,             "tcp_rtt_updates"},
1220  { 0,           1,              1,              "tcp_wscale_always"},
1221  { 0,           1,              0,              "tcp_tstamp_always"},
1222  { 0,           1,              1,              "tcp_tstamp_if_wscale"},
1223  { 0*MS,        2*HOURS,        0*MS,           "tcp_rexmit_interval_extra"},
1224  { 0,           16,             2,              "tcp_deferred_acks_max"},
1225  { 1,           16384,          4,              "tcp_slow_start_after_idle"},
1226  { 1,           4,              4,              "tcp_slow_start_initial"},
1227  { 10*MS,       50*MS,          20*MS,          "tcp_co_timer_interval"},
1228  { 0,           2,              2,              "tcp_sack_permitted"},
1229  { 0,           1,              0,              "tcp_trace"},
1230  { 0,           1,              1,              "tcp_compression_enabled"},
1231  { 0,           IPV6_MAX_HOPS,  IPV6_DEFAULT_HOPS,      "tcp_ipv6_hoplimit"},
1232  { 1,           TCP_MSS_MAX_IPV6, 1220,         "tcp_mss_def_ipv6"},
1233  { 1,           TCP_MSS_MAX_IPV6, TCP_MSS_MAX_IPV6, "tcp_mss_max_ipv6"},
1234  { 0,           1,              0,              "tcp_rev_src_routes"},
1235  { 10*MS,       500*MS,         50*MS,          "tcp_local_dack_interval"},
1236  { 100*MS,      60*SECONDS,     1*SECONDS,      "tcp_ndd_get_info_interval"},
1237  { 0,           16,             8,              "tcp_local_dacks_max"},
1238  { 0,           2,              1,              "tcp_ecn_permitted"},
1239  { 0,           1,              1,              "tcp_rst_sent_rate_enabled"},
1240  { 0,           PARAM_MAX,      40,             "tcp_rst_sent_rate"},
1241  { 0,           100*MS,         50*MS,          "tcp_push_timer_interval"},
1242  { 0,           1,              0,              "tcp_use_smss_as_mss_opt"},
1243  { 0,           PARAM_MAX,      8*MINUTES,      "tcp_keepalive_abort_interval"},
1244 };
1245 /* END CSTYLED */
1246 
1247 /*
1248  * tcp_mdt_hdr_{head,tail}_min are the leading and trailing spaces of
1249  * each header fragment in the header buffer.  Each parameter value has
1250  * to be a multiple of 4 (32-bit aligned).
1251  */
1252 static tcpparam_t lcl_tcp_mdt_head_param =
1253         { 32, 256, 32, "tcp_mdt_hdr_head_min" };
1254 static tcpparam_t lcl_tcp_mdt_tail_param =
1255         { 0,  256, 32, "tcp_mdt_hdr_tail_min" };
1256 #define tcps_mdt_hdr_head_min   tcps_mdt_head_param->tcp_param_val
1257 #define tcps_mdt_hdr_tail_min   tcps_mdt_tail_param->tcp_param_val
1258 
1259 /*
1260  * tcp_mdt_max_pbufs is the upper limit value that tcp uses to figure out
1261  * the maximum number of payload buffers associated per Multidata.
1262  */
1263 static tcpparam_t lcl_tcp_mdt_max_pbufs_param =
1264         { 1, MULTIDATA_MAX_PBUFS, MULTIDATA_MAX_PBUFS, "tcp_mdt_max_pbufs" };
1265 #define tcps_mdt_max_pbufs      tcps_mdt_max_pbufs_param->tcp_param_val
1266 
1267 /* Round up the value to the nearest mss. */
1268 #define MSS_ROUNDUP(value, mss)         ((((value) - 1) / (mss) + 1) * (mss))
1269 
1270 /*
1271  * Set ECN capable transport (ECT) code point in IP header.
1272  *
1273  * Note that there are 2 ECT code points '01' and '10', which are called
1274  * ECT(1) and ECT(0) respectively.  Here we follow the original ECT code
1275  * point ECT(0) for TCP as described in RFC 2481.
1276  */
1277 #define SET_ECT(tcp, iph) \
1278         if ((tcp)->tcp_ipversion == IPV4_VERSION) { \
1279                 /* We need to clear the code point first. */ \
1280                 ((ipha_t *)(iph))->ipha_type_of_service &= 0xFC; \
1281                 ((ipha_t *)(iph))->ipha_type_of_service |= IPH_ECN_ECT0; \
1282         } else { \
1283                 ((ip6_t *)(iph))->ip6_vcf &= htonl(0xFFCFFFFF); \
1284                 ((ip6_t *)(iph))->ip6_vcf |= htonl(IPH_ECN_ECT0 << 20); \
1285         }
1286 
1287 /*
1288  * The format argument to pass to tcp_display().
1289  * DISP_PORT_ONLY means that the returned string has only port info.
1290  * DISP_ADDR_AND_PORT means that the returned string also contains the
1291  * remote and local IP address.
1292  */
1293 #define DISP_PORT_ONLY          1
1294 #define DISP_ADDR_AND_PORT      2
1295 
1296 #define NDD_TOO_QUICK_MSG \
1297         "ndd get info rate too high for non-privileged users, try again " \
1298         "later.\n"
1299 #define NDD_OUT_OF_BUF_MSG      "<< Out of buffer >>\n"
1300 
1301 #define IS_VMLOANED_MBLK(mp) \
1302         (((mp)->b_datap->db_struioflag & STRUIO_ZC) != 0)
1303 
1304 
1305 /* Enable or disable b_cont M_MULTIDATA chaining for MDT. */
1306 boolean_t tcp_mdt_chain = B_TRUE;
1307 
1308 /*
1309  * MDT threshold in the form of effective send MSS multiplier; we take
1310  * the MDT path if the amount of unsent data exceeds the threshold value
1311  * (default threshold is 1*SMSS).
1312  */
1313 uint_t tcp_mdt_smss_threshold = 1;
1314 
1315 uint32_t do_tcpzcopy = 1;               /* 0: disable, 1: enable, 2: force */
1316 
1317 /*
1318  * Forces all connections to obey the value of the tcps_maxpsz_multiplier
1319  * tunable settable via NDD.  Otherwise, the per-connection behavior is
1320  * determined dynamically during tcp_adapt_ire(), which is the default.
1321  */
1322 boolean_t tcp_static_maxpsz = B_FALSE;
1323 
1324 /* Setable in /etc/system */
1325 /* If set to 0, pick ephemeral port sequentially; otherwise randomly. */
1326 uint32_t tcp_random_anon_port = 1;
1327 
1328 /*
1329  * To reach to an eager in Q0 which can be dropped due to an incoming
1330  * new SYN request when Q0 is full, a new doubly linked list is
1331  * introduced. This list allows to select an eager from Q0 in O(1) time.
1332  * This is needed to avoid spending too much time walking through the
1333  * long list of eagers in Q0 when tcp_drop_q0() is called. Each member of
1334  * this new list has to be a member of Q0.
1335  * This list is headed by listener's tcp_t. When the list is empty,
1336  * both the pointers - tcp_eager_next_drop_q0 and tcp_eager_prev_drop_q0,
1337  * of listener's tcp_t point to listener's tcp_t itself.
1338  *
1339  * Given an eager in Q0 and a listener, MAKE_DROPPABLE() puts the eager
1340  * in the list. MAKE_UNDROPPABLE() takes the eager out of the list.
1341  * These macros do not affect the eager's membership to Q0.
1342  */
1343 
1344 
1345 #define MAKE_DROPPABLE(listener, eager)                                 \
1346         if ((eager)->tcp_eager_next_drop_q0 == NULL) {                       \
1347                 (listener)->tcp_eager_next_drop_q0->tcp_eager_prev_drop_q0\
1348                     = (eager);                                          \
1349                 (eager)->tcp_eager_prev_drop_q0 = (listener);                \
1350                 (eager)->tcp_eager_next_drop_q0 =                    \
1351                     (listener)->tcp_eager_next_drop_q0;                      \
1352                 (listener)->tcp_eager_next_drop_q0 = (eager);                \
1353         }
1354 
1355 #define MAKE_UNDROPPABLE(eager)                                         \
1356         if ((eager)->tcp_eager_next_drop_q0 != NULL) {                       \
1357                 (eager)->tcp_eager_next_drop_q0->tcp_eager_prev_drop_q0   \
1358                     = (eager)->tcp_eager_prev_drop_q0;                       \
1359                 (eager)->tcp_eager_prev_drop_q0->tcp_eager_next_drop_q0   \
1360                     = (eager)->tcp_eager_next_drop_q0;                       \
1361                 (eager)->tcp_eager_prev_drop_q0 = NULL;                      \
1362                 (eager)->tcp_eager_next_drop_q0 = NULL;                      \
1363         }
1364 
1365 /*
1366  * If tcp_drop_ack_unsent_cnt is greater than 0, when TCP receives more
1367  * than tcp_drop_ack_unsent_cnt number of ACKs which acknowledge unsent
1368  * data, TCP will not respond with an ACK.  RFC 793 requires that
1369  * TCP responds with an ACK for such a bogus ACK.  By not following
1370  * the RFC, we prevent TCP from getting into an ACK storm if somehow
1371  * an attacker successfully spoofs an acceptable segment to our
1372  * peer; or when our peer is "confused."
1373  */
1374 uint32_t tcp_drop_ack_unsent_cnt = 10;
1375 
1376 /*
1377  * Hook functions to enable cluster networking
1378  * On non-clustered systems these vectors must always be NULL.
1379  */
1380 
1381 void (*cl_inet_listen)(uint8_t protocol, sa_family_t addr_family,
1382                             uint8_t *laddrp, in_port_t lport) = NULL;
1383 void (*cl_inet_unlisten)(uint8_t protocol, sa_family_t addr_family,
1384                             uint8_t *laddrp, in_port_t lport) = NULL;
1385 void (*cl_inet_connect)(uint8_t protocol, sa_family_t addr_family,
1386                             uint8_t *laddrp, in_port_t lport,
1387                             uint8_t *faddrp, in_port_t fport) = NULL;
1388 void (*cl_inet_disconnect)(uint8_t protocol, sa_family_t addr_family,
1389                             uint8_t *laddrp, in_port_t lport,
1390                             uint8_t *faddrp, in_port_t fport) = NULL;
1391 
1392 /*
1393  * The following are defined in ip.c
1394  */
1395 extern int (*cl_inet_isclusterwide)(uint8_t protocol, sa_family_t addr_family,
1396                                 uint8_t *laddrp);
1397 extern uint32_t (*cl_inet_ipident)(uint8_t protocol, sa_family_t addr_family,
1398                                 uint8_t *laddrp, uint8_t *faddrp);
1399 
1400 #define CL_INET_CONNECT(tcp)            {                       \
1401         if (cl_inet_connect != NULL) {                          \
1402                 /*                                              \
1403                  * Running in cluster mode - register active connection \
1404                  * information                                          \
1405                  */                                                     \
1406                 if ((tcp)->tcp_ipversion == IPV4_VERSION) {          \
1407                         if ((tcp)->tcp_ipha->ipha_src != 0) {             \
1408                                 (*cl_inet_connect)(IPPROTO_TCP, AF_INET,\
1409                                     (uint8_t *)(&((tcp)->tcp_ipha->ipha_src)),\
1410                                     (in_port_t)(tcp)->tcp_lport,     \
1411                                     (uint8_t *)(&((tcp)->tcp_ipha->ipha_dst)),\
1412                                     (in_port_t)(tcp)->tcp_fport);    \
1413                         }                                               \
1414                 } else {                                                \
1415                         if (!IN6_IS_ADDR_UNSPECIFIED(                   \
1416                             &(tcp)->tcp_ip6h->ip6_src)) {\
1417                                 (*cl_inet_connect)(IPPROTO_TCP, AF_INET6,\
1418                                     (uint8_t *)(&((tcp)->tcp_ip6h->ip6_src)),\
1419                                     (in_port_t)(tcp)->tcp_lport,     \
1420                                     (uint8_t *)(&((tcp)->tcp_ip6h->ip6_dst)),\
1421                                     (in_port_t)(tcp)->tcp_fport);    \
1422                         }                                               \
1423                 }                                                       \
1424         }                                                               \
1425 }
1426 
1427 #define CL_INET_DISCONNECT(tcp) {                               \
1428         if (cl_inet_disconnect != NULL) {                               \
1429                 /*                                                      \
1430                  * Running in cluster mode - deregister active          \
1431                  * connection information                               \
1432                  */                                                     \
1433                 if ((tcp)->tcp_ipversion == IPV4_VERSION) {          \
1434                         if ((tcp)->tcp_ip_src != 0) {                        \
1435                                 (*cl_inet_disconnect)(IPPROTO_TCP,      \
1436                                     AF_INET,                            \
1437                                     (uint8_t *)(&((tcp)->tcp_ip_src)),\
1438                                     (in_port_t)(tcp)->tcp_lport,     \
1439                                     (uint8_t *)                         \
1440                                     (&((tcp)->tcp_ipha->ipha_dst)),\
1441                                     (in_port_t)(tcp)->tcp_fport);    \
1442                         }                                               \
1443                 } else {                                                \
1444                         if (!IN6_IS_ADDR_UNSPECIFIED(                   \
1445                             &(tcp)->tcp_ip_src_v6)) {                    \
1446                                 (*cl_inet_disconnect)(IPPROTO_TCP, AF_INET6,\
1447                                     (uint8_t *)(&((tcp)->tcp_ip_src_v6)),\
1448                                     (in_port_t)(tcp)->tcp_lport,     \
1449                                     (uint8_t *)                         \
1450                                     (&((tcp)->tcp_ip6h->ip6_dst)),\
1451                                     (in_port_t)(tcp)->tcp_fport);    \
1452                         }                                               \
1453                 }                                                       \
1454         }                                                               \
1455 }
1456 
1457 /*
1458  * Cluster networking hook for traversing current connection list.
1459  * This routine is used to extract the current list of live connections
1460  * which must continue to to be dispatched to this node.
1461  */
1462 int cl_tcp_walk_list(int (*callback)(cl_tcp_info_t *, void *), void *arg);
1463 
1464 static int cl_tcp_walk_list_stack(int (*callback)(cl_tcp_info_t *, void *),
1465     void *arg, tcp_stack_t *tcps);
1466 
1467 #define DTRACE_IP_FASTPATH(mp, iph, ill, ipha, ip6h)                    \
1468         DTRACE_IP7(send, mblk_t *, mp, conn_t *, NULL, void_ip_t *,     \
1469             iph, __dtrace_ipsr_ill_t *, ill, ipha_t *, ipha,            \
1470             ip6_t *, ip6h, int, 0);
1471 
1472 /*
1473  * Figure out the value of window scale opton.  Note that the rwnd is
1474  * ASSUMED to be rounded up to the nearest MSS before the calculation.
1475  * We cannot find the scale value and then do a round up of tcp_rwnd
1476  * because the scale value may not be correct after that.
1477  *
1478  * Set the compiler flag to make this function inline.
1479  */
1480 static void
1481 tcp_set_ws_value(tcp_t *tcp)
1482 {
1483         int i;
1484         uint32_t rwnd = tcp->tcp_rwnd;
1485 
1486         for (i = 0; rwnd > TCP_MAXWIN && i < TCP_MAX_WINSHIFT;
1487             i++, rwnd >>= 1)
1488                 ;
1489         tcp->tcp_rcv_ws = i;
1490 }
1491 
1492 /*
1493  * Remove a connection from the list of detached TIME_WAIT connections.
1494  * It returns B_FALSE if it can't remove the connection from the list
1495  * as the connection has already been removed from the list due to an
1496  * earlier call to tcp_time_wait_remove(); otherwise it returns B_TRUE.
1497  */
1498 static boolean_t
1499 tcp_time_wait_remove(tcp_t *tcp, tcp_squeue_priv_t *tcp_time_wait)
1500 {
1501         boolean_t       locked = B_FALSE;
1502 
1503         if (tcp_time_wait == NULL) {
1504                 tcp_time_wait = *((tcp_squeue_priv_t **)
1505                     squeue_getprivate(tcp->tcp_connp->conn_sqp, SQPRIVATE_TCP));
1506                 mutex_enter(&tcp_time_wait->tcp_time_wait_lock);
1507                 locked = B_TRUE;
1508         } else {
1509                 ASSERT(MUTEX_HELD(&tcp_time_wait->tcp_time_wait_lock));
1510         }
1511 
1512         if (tcp->tcp_time_wait_expire == 0) {
1513                 ASSERT(tcp->tcp_time_wait_next == NULL);
1514                 ASSERT(tcp->tcp_time_wait_prev == NULL);
1515                 if (locked)
1516                         mutex_exit(&tcp_time_wait->tcp_time_wait_lock);
1517                 return (B_FALSE);
1518         }
1519         ASSERT(TCP_IS_DETACHED(tcp));
1520         ASSERT(tcp->tcp_state == TCPS_TIME_WAIT);
1521 
1522         if (tcp == tcp_time_wait->tcp_time_wait_head) {
1523                 ASSERT(tcp->tcp_time_wait_prev == NULL);
1524                 tcp_time_wait->tcp_time_wait_head = tcp->tcp_time_wait_next;
1525                 if (tcp_time_wait->tcp_time_wait_head != NULL) {
1526                         tcp_time_wait->tcp_time_wait_head->tcp_time_wait_prev =
1527                             NULL;
1528                 } else {
1529                         tcp_time_wait->tcp_time_wait_tail = NULL;
1530                 }
1531         } else if (tcp == tcp_time_wait->tcp_time_wait_tail) {
1532                 ASSERT(tcp != tcp_time_wait->tcp_time_wait_head);
1533                 ASSERT(tcp->tcp_time_wait_next == NULL);
1534                 tcp_time_wait->tcp_time_wait_tail = tcp->tcp_time_wait_prev;
1535                 ASSERT(tcp_time_wait->tcp_time_wait_tail != NULL);
1536                 tcp_time_wait->tcp_time_wait_tail->tcp_time_wait_next = NULL;
1537         } else {
1538                 ASSERT(tcp->tcp_time_wait_prev->tcp_time_wait_next == tcp);
1539                 ASSERT(tcp->tcp_time_wait_next->tcp_time_wait_prev == tcp);
1540                 tcp->tcp_time_wait_prev->tcp_time_wait_next =
1541                     tcp->tcp_time_wait_next;
1542                 tcp->tcp_time_wait_next->tcp_time_wait_prev =
1543                     tcp->tcp_time_wait_prev;
1544         }
1545         tcp->tcp_time_wait_next = NULL;
1546         tcp->tcp_time_wait_prev = NULL;
1547         tcp->tcp_time_wait_expire = 0;
1548 
1549         if (locked)
1550                 mutex_exit(&tcp_time_wait->tcp_time_wait_lock);
1551         return (B_TRUE);
1552 }
1553 
1554 /*
1555  * Add a connection to the list of detached TIME_WAIT connections
1556  * and set its time to expire.
1557  */
1558 static void
1559 tcp_time_wait_append(tcp_t *tcp)
1560 {
1561         tcp_stack_t     *tcps = tcp->tcp_tcps;
1562         tcp_squeue_priv_t *tcp_time_wait =
1563             *((tcp_squeue_priv_t **)squeue_getprivate(tcp->tcp_connp->conn_sqp,
1564             SQPRIVATE_TCP));
1565 
1566         tcp_timers_stop(tcp);
1567 
1568         /* Freed above */
1569         ASSERT(tcp->tcp_timer_tid == 0);
1570         ASSERT(tcp->tcp_ack_tid == 0);
1571 
1572         /* must have happened at the time of detaching the tcp */
1573         ASSERT(tcp->tcp_ptpahn == NULL);
1574         ASSERT(tcp->tcp_flow_stopped == 0);
1575         ASSERT(tcp->tcp_time_wait_next == NULL);
1576         ASSERT(tcp->tcp_time_wait_prev == NULL);
1577         ASSERT(tcp->tcp_time_wait_expire == NULL);
1578         ASSERT(tcp->tcp_listener == NULL);
1579 
1580         tcp->tcp_time_wait_expire = ddi_get_lbolt();
1581         /*
1582          * The value computed below in tcp->tcp_time_wait_expire may
1583          * appear negative or wrap around. That is ok since our
1584          * interest is only in the difference between the current lbolt
1585          * value and tcp->tcp_time_wait_expire. But the value should not
1586          * be zero, since it means the tcp is not in the TIME_WAIT list.
1587          * The corresponding comparison in tcp_time_wait_collector() uses
1588          * modular arithmetic.
1589          */
1590         tcp->tcp_time_wait_expire +=
1591             drv_usectohz(tcps->tcps_time_wait_interval * 1000);
1592         if (tcp->tcp_time_wait_expire == 0)
1593                 tcp->tcp_time_wait_expire = 1;
1594 
1595         ASSERT(TCP_IS_DETACHED(tcp));
1596         ASSERT(tcp->tcp_state == TCPS_TIME_WAIT);
1597         ASSERT(tcp->tcp_time_wait_next == NULL);
1598         ASSERT(tcp->tcp_time_wait_prev == NULL);
1599         TCP_DBGSTAT(tcps, tcp_time_wait);
1600 
1601         mutex_enter(&tcp_time_wait->tcp_time_wait_lock);
1602         if (tcp_time_wait->tcp_time_wait_head == NULL) {
1603                 ASSERT(tcp_time_wait->tcp_time_wait_tail == NULL);
1604                 tcp_time_wait->tcp_time_wait_head = tcp;
1605         } else {
1606                 ASSERT(tcp_time_wait->tcp_time_wait_tail != NULL);
1607                 ASSERT(tcp_time_wait->tcp_time_wait_tail->tcp_state ==
1608                     TCPS_TIME_WAIT);
1609                 tcp_time_wait->tcp_time_wait_tail->tcp_time_wait_next = tcp;
1610                 tcp->tcp_time_wait_prev = tcp_time_wait->tcp_time_wait_tail;
1611         }
1612         tcp_time_wait->tcp_time_wait_tail = tcp;
1613         mutex_exit(&tcp_time_wait->tcp_time_wait_lock);
1614 }
1615 
1616 /* ARGSUSED */
1617 void
1618 tcp_timewait_output(void *arg, mblk_t *mp, void *arg2)
1619 {
1620         conn_t  *connp = (conn_t *)arg;
1621         tcp_t   *tcp = connp->conn_tcp;
1622         tcp_stack_t     *tcps = tcp->tcp_tcps;
1623 
1624         ASSERT(tcp != NULL);
1625         if (tcp->tcp_state == TCPS_CLOSED) {
1626                 return;
1627         }
1628 
1629         ASSERT((tcp->tcp_family == AF_INET &&
1630             tcp->tcp_ipversion == IPV4_VERSION) ||
1631             (tcp->tcp_family == AF_INET6 &&
1632             (tcp->tcp_ipversion == IPV4_VERSION ||
1633             tcp->tcp_ipversion == IPV6_VERSION)));
1634         ASSERT(!tcp->tcp_listener);
1635 
1636         TCP_STAT(tcps, tcp_time_wait_reap);
1637         ASSERT(TCP_IS_DETACHED(tcp));
1638 
1639         /*
1640          * Because they have no upstream client to rebind or tcp_close()
1641          * them later, we axe the connection here and now.
1642          */
1643         tcp_close_detached(tcp);
1644 }
1645 
1646 /*
1647  * Remove cached/latched IPsec references.
1648  */
1649 void
1650 tcp_ipsec_cleanup(tcp_t *tcp)
1651 {
1652         conn_t          *connp = tcp->tcp_connp;
1653 
1654         ASSERT(connp->conn_flags & IPCL_TCPCONN);
1655 
1656         if (connp->conn_latch != NULL) {
1657                 IPLATCH_REFRELE(connp->conn_latch,
1658                     connp->conn_netstack);
1659                 connp->conn_latch = NULL;
1660         }
1661         if (connp->conn_policy != NULL) {
1662                 IPPH_REFRELE(connp->conn_policy, connp->conn_netstack);
1663                 connp->conn_policy = NULL;
1664         }
1665 }
1666 
1667 /*
1668  * Cleaup before placing on free list.
1669  * Disassociate from the netstack/tcp_stack_t since the freelist
1670  * is per squeue and not per netstack.
1671  */
1672 void
1673 tcp_cleanup(tcp_t *tcp)
1674 {
1675         mblk_t          *mp;
1676         char            *tcp_iphc;
1677         int             tcp_iphc_len;
1678         int             tcp_hdr_grown;
1679         tcp_sack_info_t *tcp_sack_info;
1680         conn_t          *connp = tcp->tcp_connp;
1681         tcp_stack_t     *tcps = tcp->tcp_tcps;
1682         netstack_t      *ns = tcps->tcps_netstack;
1683 
1684         tcp_bind_hash_remove(tcp);
1685 
1686         /* Cleanup that which needs the netstack first */
1687         tcp_ipsec_cleanup(tcp);
1688 
1689         tcp_free(tcp);
1690 
1691         /* Release any SSL context */
1692         if (tcp->tcp_kssl_ent != NULL) {
1693                 kssl_release_ent(tcp->tcp_kssl_ent, NULL, KSSL_NO_PROXY);
1694                 tcp->tcp_kssl_ent = NULL;
1695         }
1696 
1697         if (tcp->tcp_kssl_ctx != NULL) {
1698                 kssl_release_ctx(tcp->tcp_kssl_ctx);
1699                 tcp->tcp_kssl_ctx = NULL;
1700         }
1701         tcp->tcp_kssl_pending = B_FALSE;
1702 
1703         conn_delete_ire(connp, NULL);
1704 
1705         /*
1706          * Since we will bzero the entire structure, we need to
1707          * remove it and reinsert it in global hash list. We
1708          * know the walkers can't get to this conn because we
1709          * had set CONDEMNED flag earlier and checked reference
1710          * under conn_lock so walker won't pick it and when we
1711          * go the ipcl_globalhash_remove() below, no walker
1712          * can get to it.
1713          */
1714         ipcl_globalhash_remove(connp);
1715 
1716         /*
1717          * Now it is safe to decrement the reference counts.
1718          * This might be the last reference on the netstack and TCPS
1719          * in which case it will cause the tcp_g_q_close and
1720          * the freeing of the IP Instance.
1721          */
1722         connp->conn_netstack = NULL;
1723         netstack_rele(ns);
1724         ASSERT(tcps != NULL);
1725         tcp->tcp_tcps = NULL;
1726         TCPS_REFRELE(tcps);
1727 
1728         /* Save some state */
1729         mp = tcp->tcp_timercache;
1730 
1731         tcp_sack_info = tcp->tcp_sack_info;
1732         tcp_iphc = tcp->tcp_iphc;
1733         tcp_iphc_len = tcp->tcp_iphc_len;
1734         tcp_hdr_grown = tcp->tcp_hdr_grown;
1735 
1736         if (connp->conn_cred != NULL) {
1737                 crfree(connp->conn_cred);
1738                 connp->conn_cred = NULL;
1739         }
1740         if (connp->conn_peercred != NULL) {
1741                 crfree(connp->conn_peercred);
1742                 connp->conn_peercred = NULL;
1743         }
1744         ipcl_conn_cleanup(connp);
1745         connp->conn_flags = IPCL_TCPCONN;
1746         bzero(tcp, sizeof (tcp_t));
1747 
1748         /* restore the state */
1749         tcp->tcp_timercache = mp;
1750 
1751         tcp->tcp_sack_info = tcp_sack_info;
1752         tcp->tcp_iphc = tcp_iphc;
1753         tcp->tcp_iphc_len = tcp_iphc_len;
1754         tcp->tcp_hdr_grown = tcp_hdr_grown;
1755 
1756         tcp->tcp_connp = connp;
1757 
1758         ASSERT(connp->conn_tcp == tcp);
1759         ASSERT(connp->conn_flags & IPCL_TCPCONN);
1760         connp->conn_state_flags = CONN_INCIPIENT;
1761         ASSERT(connp->conn_ulp == IPPROTO_TCP);
1762         ASSERT(connp->conn_ref == 1);
1763 }
1764 
1765 /*
1766  * Blows away all tcps whose TIME_WAIT has expired. List traversal
1767  * is done forwards from the head.
1768  * This walks all stack instances since
1769  * tcp_time_wait remains global across all stacks.
1770  */
1771 /* ARGSUSED */
1772 void
1773 tcp_time_wait_collector(void *arg)
1774 {
1775         tcp_t *tcp;
1776         clock_t now;
1777         mblk_t *mp;
1778         conn_t *connp;
1779         kmutex_t *lock;
1780         boolean_t removed;
1781 
1782         squeue_t *sqp = (squeue_t *)arg;
1783         tcp_squeue_priv_t *tcp_time_wait =
1784             *((tcp_squeue_priv_t **)squeue_getprivate(sqp, SQPRIVATE_TCP));
1785 
1786         mutex_enter(&tcp_time_wait->tcp_time_wait_lock);
1787         tcp_time_wait->tcp_time_wait_tid = 0;
1788 
1789         if (tcp_time_wait->tcp_free_list != NULL &&
1790             tcp_time_wait->tcp_free_list->tcp_in_free_list == B_TRUE) {
1791                 TCP_G_STAT(tcp_freelist_cleanup);
1792                 while ((tcp = tcp_time_wait->tcp_free_list) != NULL) {
1793                         tcp_time_wait->tcp_free_list = tcp->tcp_time_wait_next;
1794                         tcp->tcp_time_wait_next = NULL;
1795                         tcp_time_wait->tcp_free_list_cnt--;
1796                         ASSERT(tcp->tcp_tcps == NULL);
1797                         CONN_DEC_REF(tcp->tcp_connp);
1798                 }
1799                 ASSERT(tcp_time_wait->tcp_free_list_cnt == 0);
1800         }
1801 
1802         /*
1803          * In order to reap time waits reliably, we should use a
1804          * source of time that is not adjustable by the user -- hence
1805          * the call to ddi_get_lbolt().
1806          */
1807         now = ddi_get_lbolt();
1808         while ((tcp = tcp_time_wait->tcp_time_wait_head) != NULL) {
1809                 /*
1810                  * Compare times using modular arithmetic, since
1811                  * lbolt can wrapover.
1812                  */
1813                 if ((now - tcp->tcp_time_wait_expire) < 0) {
1814                         break;
1815                 }
1816 
1817                 removed = tcp_time_wait_remove(tcp, tcp_time_wait);
1818                 ASSERT(removed);
1819 
1820                 connp = tcp->tcp_connp;
1821                 ASSERT(connp->conn_fanout != NULL);
1822                 lock = &connp->conn_fanout->connf_lock;
1823                 /*
1824                  * This is essentially a TW reclaim fast path optimization for
1825                  * performance where the timewait collector checks under the
1826                  * fanout lock (so that no one else can get access to the
1827                  * conn_t) that the refcnt is 2 i.e. one for TCP and one for
1828                  * the classifier hash list. If ref count is indeed 2, we can
1829                  * just remove the conn under the fanout lock and avoid
1830                  * cleaning up the conn under the squeue, provided that
1831                  * clustering callbacks are not enabled. If clustering is
1832                  * enabled, we need to make the clustering callback before
1833                  * setting the CONDEMNED flag and after dropping all locks and
1834                  * so we forego this optimization and fall back to the slow
1835                  * path. Also please see the comments in tcp_closei_local
1836                  * regarding the refcnt logic.
1837                  *
1838                  * Since we are holding the tcp_time_wait_lock, its better
1839                  * not to block on the fanout_lock because other connections
1840                  * can't add themselves to time_wait list. So we do a
1841                  * tryenter instead of mutex_enter.
1842                  */
1843                 if (mutex_tryenter(lock)) {
1844                         mutex_enter(&connp->conn_lock);
1845                         if ((connp->conn_ref == 2) &&
1846                             (cl_inet_disconnect == NULL)) {
1847                                 ipcl_hash_remove_locked(connp,
1848                                     connp->conn_fanout);
1849                                 /*
1850                                  * Set the CONDEMNED flag now itself so that
1851                                  * the refcnt cannot increase due to any
1852                                  * walker. But we have still not cleaned up
1853                                  * conn_ire_cache. This is still ok since
1854                                  * we are going to clean it up in tcp_cleanup
1855                                  * immediately and any interface unplumb
1856                                  * thread will wait till the ire is blown away
1857                                  */
1858                                 connp->conn_state_flags |= CONN_CONDEMNED;
1859                                 mutex_exit(lock);
1860                                 mutex_exit(&connp->conn_lock);
1861                                 if (tcp_time_wait->tcp_free_list_cnt <
1862                                     tcp_free_list_max_cnt) {
1863                                         /* Add to head of tcp_free_list */
1864                                         mutex_exit(
1865                                             &tcp_time_wait->tcp_time_wait_lock);
1866                                         tcp_cleanup(tcp);
1867                                         ASSERT(connp->conn_latch == NULL);
1868                                         ASSERT(connp->conn_policy == NULL);
1869                                         ASSERT(tcp->tcp_tcps == NULL);
1870                                         ASSERT(connp->conn_netstack == NULL);
1871 
1872                                         mutex_enter(
1873                                             &tcp_time_wait->tcp_time_wait_lock);
1874                                         tcp->tcp_time_wait_next =
1875                                             tcp_time_wait->tcp_free_list;
1876                                         tcp_time_wait->tcp_free_list = tcp;
1877                                         tcp_time_wait->tcp_free_list_cnt++;
1878                                         continue;
1879                                 } else {
1880                                         /* Do not add to tcp_free_list */
1881                                         mutex_exit(
1882                                             &tcp_time_wait->tcp_time_wait_lock);
1883                                         tcp_bind_hash_remove(tcp);
1884                                         conn_delete_ire(tcp->tcp_connp, NULL);
1885                                         tcp_ipsec_cleanup(tcp);
1886                                         CONN_DEC_REF(tcp->tcp_connp);
1887                                 }
1888                         } else {
1889                                 CONN_INC_REF_LOCKED(connp);
1890                                 mutex_exit(lock);
1891                                 mutex_exit(&tcp_time_wait->tcp_time_wait_lock);
1892                                 mutex_exit(&connp->conn_lock);
1893                                 /*
1894                                  * We can reuse the closemp here since conn has
1895                                  * detached (otherwise we wouldn't even be in
1896                                  * time_wait list). tcp_closemp_used can safely
1897                                  * be changed without taking a lock as no other
1898                                  * thread can concurrently access it at this
1899                                  * point in the connection lifecycle.
1900                                  */
1901 
1902                                 if (tcp->tcp_closemp.b_prev == NULL)
1903                                         tcp->tcp_closemp_used = B_TRUE;
1904                                 else
1905                                         cmn_err(CE_PANIC,
1906                                             "tcp_timewait_collector: "
1907                                             "concurrent use of tcp_closemp: "
1908                                             "connp %p tcp %p\n", (void *)connp,
1909                                             (void *)tcp);
1910 
1911                                 TCP_DEBUG_GETPCSTACK(tcp->tcmp_stk, 15);
1912                                 mp = &tcp->tcp_closemp;
1913                                 squeue_fill(connp->conn_sqp, mp,
1914                                     tcp_timewait_output, connp,
1915                                     SQTAG_TCP_TIMEWAIT);
1916                         }
1917                 } else {
1918                         mutex_enter(&connp->conn_lock);
1919                         CONN_INC_REF_LOCKED(connp);
1920                         mutex_exit(&tcp_time_wait->tcp_time_wait_lock);
1921                         mutex_exit(&connp->conn_lock);
1922                         /*
1923                          * We can reuse the closemp here since conn has
1924                          * detached (otherwise we wouldn't even be in
1925                          * time_wait list). tcp_closemp_used can safely
1926                          * be changed without taking a lock as no other
1927                          * thread can concurrently access it at this
1928                          * point in the connection lifecycle.
1929                          */
1930 
1931                         if (tcp->tcp_closemp.b_prev == NULL)
1932                                 tcp->tcp_closemp_used = B_TRUE;
1933                         else
1934                                 cmn_err(CE_PANIC, "tcp_timewait_collector: "
1935                                     "concurrent use of tcp_closemp: "
1936                                     "connp %p tcp %p\n", (void *)connp,
1937                                     (void *)tcp);
1938 
1939                         TCP_DEBUG_GETPCSTACK(tcp->tcmp_stk, 15);
1940                         mp = &tcp->tcp_closemp;
1941                         squeue_fill(connp->conn_sqp, mp,
1942                             tcp_timewait_output, connp, 0);
1943                 }
1944                 mutex_enter(&tcp_time_wait->tcp_time_wait_lock);
1945         }
1946 
1947         if (tcp_time_wait->tcp_free_list != NULL)
1948                 tcp_time_wait->tcp_free_list->tcp_in_free_list = B_TRUE;
1949 
1950         tcp_time_wait->tcp_time_wait_tid =
1951             timeout(tcp_time_wait_collector, sqp, TCP_TIME_WAIT_DELAY);
1952         mutex_exit(&tcp_time_wait->tcp_time_wait_lock);
1953 }
1954 /*
1955  * Reply to a clients T_CONN_RES TPI message. This function
1956  * is used only for TLI/XTI listener. Sockfs sends T_CONN_RES
1957  * on the acceptor STREAM and processed in tcp_wput_accept().
1958  * Read the block comment on top of tcp_conn_request().
1959  */
1960 static void
1961 tcp_accept(tcp_t *listener, mblk_t *mp)
1962 {
1963         tcp_t   *acceptor;
1964         tcp_t   *eager;
1965         tcp_t   *tcp;
1966         struct T_conn_res       *tcr;
1967         t_uscalar_t     acceptor_id;
1968         t_scalar_t      seqnum;
1969         mblk_t  *opt_mp = NULL; /* T_OPTMGMT_REQ messages */
1970         mblk_t  *ok_mp;
1971         mblk_t  *mp1;
1972         tcp_stack_t     *tcps = listener->tcp_tcps;
1973 
1974         if ((mp->b_wptr - mp->b_rptr) < sizeof (*tcr)) {
1975                 tcp_err_ack(listener, mp, TPROTO, 0);
1976                 return;
1977         }
1978         tcr = (struct T_conn_res *)mp->b_rptr;
1979 
1980         /*
1981          * Under ILP32 the stream head points tcr->ACCEPTOR_id at the
1982          * read side queue of the streams device underneath us i.e. the
1983          * read side queue of 'ip'. Since we can't deference QUEUE_ptr we
1984          * look it up in the queue_hash.  Under LP64 it sends down the
1985          * minor_t of the accepting endpoint.
1986          *
1987          * Once the acceptor/eager are modified (in tcp_accept_swap) the
1988          * fanout hash lock is held.
1989          * This prevents any thread from entering the acceptor queue from
1990          * below (since it has not been hard bound yet i.e. any inbound
1991          * packets will arrive on the listener or default tcp queue and
1992          * go through tcp_lookup).
1993          * The CONN_INC_REF will prevent the acceptor from closing.
1994          *
1995          * XXX It is still possible for a tli application to send down data
1996          * on the accepting stream while another thread calls t_accept.
1997          * This should not be a problem for well-behaved applications since
1998          * the T_OK_ACK is sent after the queue swapping is completed.
1999          *
2000          * If the accepting fd is the same as the listening fd, avoid
2001          * queue hash lookup since that will return an eager listener in a
2002          * already established state.
2003          */
2004         acceptor_id = tcr->ACCEPTOR_id;
2005         mutex_enter(&listener->tcp_eager_lock);
2006         if (listener->tcp_acceptor_id == acceptor_id) {
2007                 eager = listener->tcp_eager_next_q;
2008                 /* only count how many T_CONN_INDs so don't count q0 */
2009                 if ((listener->tcp_conn_req_cnt_q != 1) ||
2010                     (eager->tcp_conn_req_seqnum != tcr->SEQ_number)) {
2011                         mutex_exit(&listener->tcp_eager_lock);
2012                         tcp_err_ack(listener, mp, TBADF, 0);
2013                         return;
2014                 }
2015                 if (listener->tcp_conn_req_cnt_q0 != 0) {
2016                         /* Throw away all the eagers on q0. */
2017                         tcp_eager_cleanup(listener, 1);
2018                 }
2019                 if (listener->tcp_syn_defense) {
2020                         listener->tcp_syn_defense = B_FALSE;
2021                         if (listener->tcp_ip_addr_cache != NULL) {
2022                                 kmem_free(listener->tcp_ip_addr_cache,
2023                                     IP_ADDR_CACHE_SIZE * sizeof (ipaddr_t));
2024                                 listener->tcp_ip_addr_cache = NULL;
2025                         }
2026                 }
2027                 /*
2028                  * Transfer tcp_conn_req_max to the eager so that when
2029                  * a disconnect occurs we can revert the endpoint to the
2030                  * listen state.
2031                  */
2032                 eager->tcp_conn_req_max = listener->tcp_conn_req_max;
2033                 ASSERT(listener->tcp_conn_req_cnt_q0 == 0);
2034                 /*
2035                  * Get a reference on the acceptor just like the
2036                  * tcp_acceptor_hash_lookup below.
2037                  */
2038                 acceptor = listener;
2039                 CONN_INC_REF(acceptor->tcp_connp);
2040         } else {
2041                 acceptor = tcp_acceptor_hash_lookup(acceptor_id, tcps);
2042                 if (acceptor == NULL) {
2043                         if (listener->tcp_debug) {
2044                                 (void) strlog(TCP_MOD_ID, 0, 1,
2045                                     SL_ERROR|SL_TRACE,
2046                                     "tcp_accept: did not find acceptor 0x%x\n",
2047                                     acceptor_id);
2048                         }
2049                         mutex_exit(&listener->tcp_eager_lock);
2050                         tcp_err_ack(listener, mp, TPROVMISMATCH, 0);
2051                         return;
2052                 }
2053                 /*
2054                  * Verify acceptor state. The acceptable states for an acceptor
2055                  * include TCPS_IDLE and TCPS_BOUND.
2056                  */
2057                 switch (acceptor->tcp_state) {
2058                 case TCPS_IDLE:
2059                         /* FALLTHRU */
2060                 case TCPS_BOUND:
2061                         break;
2062                 default:
2063                         CONN_DEC_REF(acceptor->tcp_connp);
2064                         mutex_exit(&listener->tcp_eager_lock);
2065                         tcp_err_ack(listener, mp, TOUTSTATE, 0);
2066                         return;
2067                 }
2068         }
2069 
2070         /* The listener must be in TCPS_LISTEN */
2071         if (listener->tcp_state != TCPS_LISTEN) {
2072                 CONN_DEC_REF(acceptor->tcp_connp);
2073                 mutex_exit(&listener->tcp_eager_lock);
2074                 tcp_err_ack(listener, mp, TOUTSTATE, 0);
2075                 return;
2076         }
2077 
2078         /*
2079          * Rendezvous with an eager connection request packet hanging off
2080          * 'tcp' that has the 'seqnum' tag.  We tagged the detached open
2081          * tcp structure when the connection packet arrived in
2082          * tcp_conn_request().
2083          */
2084         seqnum = tcr->SEQ_number;
2085         eager = listener;
2086         do {
2087                 eager = eager->tcp_eager_next_q;
2088                 if (eager == NULL) {
2089                         CONN_DEC_REF(acceptor->tcp_connp);
2090                         mutex_exit(&listener->tcp_eager_lock);
2091                         tcp_err_ack(listener, mp, TBADSEQ, 0);
2092                         return;
2093                 }
2094         } while (eager->tcp_conn_req_seqnum != seqnum);
2095         mutex_exit(&listener->tcp_eager_lock);
2096 
2097         /*
2098          * At this point, both acceptor and listener have 2 ref
2099          * that they begin with. Acceptor has one additional ref
2100          * we placed in lookup while listener has 3 additional
2101          * ref for being behind the squeue (tcp_accept() is
2102          * done on listener's squeue); being in classifier hash;
2103          * and eager's ref on listener.
2104          */
2105         ASSERT(listener->tcp_connp->conn_ref >= 5);
2106         ASSERT(acceptor->tcp_connp->conn_ref >= 3);
2107 
2108         /*
2109          * The eager at this point is set in its own squeue and
2110          * could easily have been killed (tcp_accept_finish will
2111          * deal with that) because of a TH_RST so we can only
2112          * ASSERT for a single ref.
2113          */
2114         ASSERT(eager->tcp_connp->conn_ref >= 1);
2115 
2116         /* Pre allocate the stroptions mblk also */
2117         opt_mp = allocb(sizeof (struct stroptions), BPRI_HI);
2118         if (opt_mp == NULL) {
2119                 CONN_DEC_REF(acceptor->tcp_connp);
2120                 CONN_DEC_REF(eager->tcp_connp);
2121                 tcp_err_ack(listener, mp, TSYSERR, ENOMEM);
2122                 return;
2123         }
2124         DB_TYPE(opt_mp) = M_SETOPTS;
2125         opt_mp->b_wptr += sizeof (struct stroptions);
2126 
2127         /*
2128          * Prepare for inheriting IPV6_BOUND_IF and IPV6_RECVPKTINFO
2129          * from listener to acceptor. The message is chained on opt_mp
2130          * which will be sent onto eager's squeue.
2131          */
2132         if (listener->tcp_bound_if != 0) {
2133                 /* allocate optmgmt req */
2134                 mp1 = tcp_setsockopt_mp(IPPROTO_IPV6,
2135                     IPV6_BOUND_IF, (char *)&listener->tcp_bound_if,
2136                     sizeof (int));
2137                 if (mp1 != NULL)
2138                         linkb(opt_mp, mp1);
2139         }
2140         if (listener->tcp_ipv6_recvancillary & TCP_IPV6_RECVPKTINFO) {
2141                 uint_t on = 1;
2142 
2143                 /* allocate optmgmt req */
2144                 mp1 = tcp_setsockopt_mp(IPPROTO_IPV6,
2145                     IPV6_RECVPKTINFO, (char *)&on, sizeof (on));
2146                 if (mp1 != NULL)
2147                         linkb(opt_mp, mp1);
2148         }
2149 
2150         /* Re-use mp1 to hold a copy of mp, in case reallocb fails */
2151         if ((mp1 = copymsg(mp)) == NULL) {
2152                 CONN_DEC_REF(acceptor->tcp_connp);
2153                 CONN_DEC_REF(eager->tcp_connp);
2154                 freemsg(opt_mp);
2155                 tcp_err_ack(listener, mp, TSYSERR, ENOMEM);
2156                 return;
2157         }
2158 
2159         tcr = (struct T_conn_res *)mp1->b_rptr;
2160 
2161         /*
2162          * This is an expanded version of mi_tpi_ok_ack_alloc()
2163          * which allocates a larger mblk and appends the new
2164          * local address to the ok_ack.  The address is copied by
2165          * soaccept() for getsockname().
2166          */
2167         {
2168                 int extra;
2169 
2170                 extra = (eager->tcp_family == AF_INET) ?
2171                     sizeof (sin_t) : sizeof (sin6_t);
2172 
2173                 /*
2174                  * Try to re-use mp, if possible.  Otherwise, allocate
2175                  * an mblk and return it as ok_mp.  In any case, mp
2176                  * is no longer usable upon return.
2177                  */
2178                 if ((ok_mp = mi_tpi_ok_ack_alloc_extra(mp, extra)) == NULL) {
2179                         CONN_DEC_REF(acceptor->tcp_connp);
2180                         CONN_DEC_REF(eager->tcp_connp);
2181                         freemsg(opt_mp);
2182                         /* Original mp has been freed by now, so use mp1 */
2183                         tcp_err_ack(listener, mp1, TSYSERR, ENOMEM);
2184                         return;
2185                 }
2186 
2187                 mp = NULL;      /* We should never use mp after this point */
2188 
2189                 switch (extra) {
2190                 case sizeof (sin_t): {
2191                                 sin_t *sin = (sin_t *)ok_mp->b_wptr;
2192 
2193                                 ok_mp->b_wptr += extra;
2194                                 sin->sin_family = AF_INET;
2195                                 sin->sin_port = eager->tcp_lport;
2196                                 sin->sin_addr.s_addr =
2197                                     eager->tcp_ipha->ipha_src;
2198                                 break;
2199                         }
2200                 case sizeof (sin6_t): {
2201                                 sin6_t *sin6 = (sin6_t *)ok_mp->b_wptr;
2202 
2203                                 ok_mp->b_wptr += extra;
2204                                 sin6->sin6_family = AF_INET6;
2205                                 sin6->sin6_port = eager->tcp_lport;
2206                                 if (eager->tcp_ipversion == IPV4_VERSION) {
2207                                         sin6->sin6_flowinfo = 0;
2208                                         IN6_IPADDR_TO_V4MAPPED(
2209                                             eager->tcp_ipha->ipha_src,
2210                                             &sin6->sin6_addr);
2211                                 } else {
2212                                         ASSERT(eager->tcp_ip6h != NULL);
2213                                         sin6->sin6_flowinfo =
2214                                             eager->tcp_ip6h->ip6_vcf &
2215                                             ~IPV6_VERS_AND_FLOW_MASK;
2216                                         sin6->sin6_addr =
2217                                             eager->tcp_ip6h->ip6_src;
2218                                 }
2219                                 sin6->sin6_scope_id = 0;
2220                                 sin6->__sin6_src_id = 0;
2221                                 break;
2222                         }
2223                 default:
2224                         break;
2225                 }
2226                 ASSERT(ok_mp->b_wptr <= ok_mp->b_datap->db_lim);
2227         }
2228 
2229         /*
2230          * If there are no options we know that the T_CONN_RES will
2231          * succeed. However, we can't send the T_OK_ACK upstream until
2232          * the tcp_accept_swap is done since it would be dangerous to
2233          * let the application start using the new fd prior to the swap.
2234          */
2235         tcp_accept_swap(listener, acceptor, eager);
2236 
2237         /*
2238          * tcp_accept_swap unlinks eager from listener but does not drop
2239          * the eager's reference on the listener.
2240          */
2241         ASSERT(eager->tcp_listener == NULL);
2242         ASSERT(listener->tcp_connp->conn_ref >= 5);
2243 
2244         /*
2245          * The eager is now associated with its own queue. Insert in
2246          * the hash so that the connection can be reused for a future
2247          * T_CONN_RES.
2248          */
2249         tcp_acceptor_hash_insert(acceptor_id, eager);
2250 
2251         /*
2252          * We now do the processing of options with T_CONN_RES.
2253          * We delay till now since we wanted to have queue to pass to
2254          * option processing routines that points back to the right
2255          * instance structure which does not happen until after
2256          * tcp_accept_swap().
2257          *
2258          * Note:
2259          * The sanity of the logic here assumes that whatever options
2260          * are appropriate to inherit from listner=>eager are done
2261          * before this point, and whatever were to be overridden (or not)
2262          * in transfer logic from eager=>acceptor in tcp_accept_swap().
2263          * [ Warning: acceptor endpoint can have T_OPTMGMT_REQ done to it
2264          *   before its ACCEPTOR_id comes down in T_CONN_RES ]
2265          * This may not be true at this point in time but can be fixed
2266          * independently. This option processing code starts with
2267          * the instantiated acceptor instance and the final queue at
2268          * this point.
2269          */
2270 
2271         if (tcr->OPT_length != 0) {
2272                 /* Options to process */
2273                 int t_error = 0;
2274                 int sys_error = 0;
2275                 int do_disconnect = 0;
2276 
2277                 if (tcp_conprim_opt_process(eager, mp1,
2278                     &do_disconnect, &t_error, &sys_error) < 0) {
2279                         eager->tcp_accept_error = 1;
2280                         if (do_disconnect) {
2281                                 /*
2282                                  * An option failed which does not allow
2283                                  * connection to be accepted.
2284                                  *
2285                                  * We allow T_CONN_RES to succeed and
2286                                  * put a T_DISCON_IND on the eager queue.
2287                                  */
2288                                 ASSERT(t_error == 0 && sys_error == 0);
2289                                 eager->tcp_send_discon_ind = 1;
2290                         } else {
2291                                 ASSERT(t_error != 0);
2292                                 freemsg(ok_mp);
2293                                 /*
2294                                  * Original mp was either freed or set
2295                                  * to ok_mp above, so use mp1 instead.
2296                                  */
2297                                 tcp_err_ack(listener, mp1, t_error, sys_error);
2298                                 goto finish;
2299                         }
2300                 }
2301                 /*
2302                  * Most likely success in setting options (except if
2303                  * eager->tcp_send_discon_ind set).
2304                  * mp1 option buffer represented by OPT_length/offset
2305                  * potentially modified and contains results of setting
2306                  * options at this point
2307                  */
2308         }
2309 
2310         /* We no longer need mp1, since all options processing has passed */
2311         freemsg(mp1);
2312 
2313         putnext(listener->tcp_rq, ok_mp);
2314 
2315         mutex_enter(&listener->tcp_eager_lock);
2316         if (listener->tcp_eager_prev_q0->tcp_conn_def_q0) {
2317                 tcp_t   *tail;
2318                 mblk_t  *conn_ind;
2319 
2320                 /*
2321                  * This path should not be executed if listener and
2322                  * acceptor streams are the same.
2323                  */
2324                 ASSERT(listener != acceptor);
2325 
2326                 tcp = listener->tcp_eager_prev_q0;
2327                 /*
2328                  * listener->tcp_eager_prev_q0 points to the TAIL of the
2329                  * deferred T_conn_ind queue. We need to get to the head of
2330                  * the queue in order to send up T_conn_ind the same order as
2331                  * how the 3WHS is completed.
2332                  */
2333                 while (tcp != listener) {
2334                         if (!tcp->tcp_eager_prev_q0->tcp_conn_def_q0)
2335                                 break;
2336                         else
2337                                 tcp = tcp->tcp_eager_prev_q0;
2338                 }
2339                 ASSERT(tcp != listener);
2340                 conn_ind = tcp->tcp_conn.tcp_eager_conn_ind;
2341                 ASSERT(conn_ind != NULL);
2342                 tcp->tcp_conn.tcp_eager_conn_ind = NULL;
2343 
2344                 /* Move from q0 to q */
2345                 ASSERT(listener->tcp_conn_req_cnt_q0 > 0);
2346                 listener->tcp_conn_req_cnt_q0--;
2347                 listener->tcp_conn_req_cnt_q++;
2348                 tcp->tcp_eager_next_q0->tcp_eager_prev_q0 =
2349                     tcp->tcp_eager_prev_q0;
2350                 tcp->tcp_eager_prev_q0->tcp_eager_next_q0 =
2351                     tcp->tcp_eager_next_q0;
2352                 tcp->tcp_eager_prev_q0 = NULL;
2353                 tcp->tcp_eager_next_q0 = NULL;
2354                 tcp->tcp_conn_def_q0 = B_FALSE;
2355 
2356                 /* Make sure the tcp isn't in the list of droppables */
2357                 ASSERT(tcp->tcp_eager_next_drop_q0 == NULL &&
2358                     tcp->tcp_eager_prev_drop_q0 == NULL);
2359 
2360                 /*
2361                  * Insert at end of the queue because sockfs sends
2362                  * down T_CONN_RES in chronological order. Leaving
2363                  * the older conn indications at front of the queue
2364                  * helps reducing search time.
2365                  */
2366                 tail = listener->tcp_eager_last_q;
2367                 if (tail != NULL)
2368                         tail->tcp_eager_next_q = tcp;
2369                 else
2370                         listener->tcp_eager_next_q = tcp;
2371                 listener->tcp_eager_last_q = tcp;
2372                 tcp->tcp_eager_next_q = NULL;
2373                 mutex_exit(&listener->tcp_eager_lock);
2374                 putnext(tcp->tcp_rq, conn_ind);
2375         } else {
2376                 mutex_exit(&listener->tcp_eager_lock);
2377         }
2378 
2379         /*
2380          * Done with the acceptor - free it
2381          *
2382          * Note: from this point on, no access to listener should be made
2383          * as listener can be equal to acceptor.
2384          */
2385 finish:
2386         ASSERT(acceptor->tcp_detached);
2387         ASSERT(tcps->tcps_g_q != NULL);
2388         acceptor->tcp_rq = tcps->tcps_g_q;
2389         acceptor->tcp_wq = WR(tcps->tcps_g_q);
2390         (void) tcp_clean_death(acceptor, 0, 2);
2391         CONN_DEC_REF(acceptor->tcp_connp);
2392 
2393         /*
2394          * In case we already received a FIN we have to make tcp_rput send
2395          * the ordrel_ind. This will also send up a window update if the window
2396          * has opened up.
2397          *
2398          * In the normal case of a successful connection acceptance
2399          * we give the O_T_BIND_REQ to the read side put procedure as an
2400          * indication that this was just accepted. This tells tcp_rput to
2401          * pass up any data queued in tcp_rcv_list.
2402          *
2403          * In the fringe case where options sent with T_CONN_RES failed and
2404          * we required, we would be indicating a T_DISCON_IND to blow
2405          * away this connection.
2406          */
2407 
2408         /*
2409          * XXX: we currently have a problem if XTI application closes the
2410          * acceptor stream in between. This problem exists in on10-gate also
2411          * and is well know but nothing can be done short of major rewrite
2412          * to fix it. Now it is possible to take care of it by assigning TLI/XTI
2413          * eager same squeue as listener (we can distinguish non socket
2414          * listeners at the time of handling a SYN in tcp_conn_request)
2415          * and do most of the work that tcp_accept_finish does here itself
2416          * and then get behind the acceptor squeue to access the acceptor
2417          * queue.
2418          */
2419         /*
2420          * We already have a ref on tcp so no need to do one before squeue_fill
2421          */
2422         squeue_fill(eager->tcp_connp->conn_sqp, opt_mp,
2423             tcp_accept_finish, eager->tcp_connp, SQTAG_TCP_ACCEPT_FINISH);
2424 }
2425 
2426 /*
2427  * Swap information between the eager and acceptor for a TLI/XTI client.
2428  * The sockfs accept is done on the acceptor stream and control goes
2429  * through tcp_wput_accept() and tcp_accept()/tcp_accept_swap() is not
2430  * called. In either case, both the eager and listener are in their own
2431  * perimeter (squeue) and the code has to deal with potential race.
2432  *
2433  * See the block comment on top of tcp_accept() and tcp_wput_accept().
2434  */
2435 static void
2436 tcp_accept_swap(tcp_t *listener, tcp_t *acceptor, tcp_t *eager)
2437 {
2438         conn_t  *econnp, *aconnp;
2439 
2440         ASSERT(eager->tcp_rq == listener->tcp_rq);
2441         ASSERT(eager->tcp_detached && !acceptor->tcp_detached);
2442         ASSERT(!eager->tcp_hard_bound);
2443         ASSERT(!TCP_IS_SOCKET(acceptor));
2444         ASSERT(!TCP_IS_SOCKET(eager));
2445         ASSERT(!TCP_IS_SOCKET(listener));
2446 
2447         acceptor->tcp_detached = B_TRUE;
2448         /*
2449          * To permit stream re-use by TLI/XTI, the eager needs a copy of
2450          * the acceptor id.
2451          */
2452         eager->tcp_acceptor_id = acceptor->tcp_acceptor_id;
2453 
2454         /* remove eager from listen list... */
2455         mutex_enter(&listener->tcp_eager_lock);
2456         tcp_eager_unlink(eager);
2457         ASSERT(eager->tcp_eager_next_q == NULL &&
2458             eager->tcp_eager_last_q == NULL);
2459         ASSERT(eager->tcp_eager_next_q0 == NULL &&
2460             eager->tcp_eager_prev_q0 == NULL);
2461         mutex_exit(&listener->tcp_eager_lock);
2462         eager->tcp_rq = acceptor->tcp_rq;
2463         eager->tcp_wq = acceptor->tcp_wq;
2464 
2465         econnp = eager->tcp_connp;
2466         aconnp = acceptor->tcp_connp;
2467 
2468         eager->tcp_rq->q_ptr = econnp;
2469         eager->tcp_wq->q_ptr = econnp;
2470 
2471         /*
2472          * In the TLI/XTI loopback case, we are inside the listener's squeue,
2473          * which might be a different squeue from our peer TCP instance.
2474          * For TCP Fusion, the peer expects that whenever tcp_detached is
2475          * clear, our TCP queues point to the acceptor's queues.  Thus, use
2476          * membar_producer() to ensure that the assignments of tcp_rq/tcp_wq
2477          * above reach global visibility prior to the clearing of tcp_detached.
2478          */
2479         membar_producer();
2480         eager->tcp_detached = B_FALSE;
2481 
2482         ASSERT(eager->tcp_ack_tid == 0);
2483 
2484         econnp->conn_dev = aconnp->conn_dev;
2485         econnp->conn_minor_arena = aconnp->conn_minor_arena;
2486         ASSERT(econnp->conn_minor_arena != NULL);
2487         if (eager->tcp_cred != NULL)
2488                 crfree(eager->tcp_cred);
2489         eager->tcp_cred = econnp->conn_cred = aconnp->conn_cred;
2490         ASSERT(econnp->conn_netstack == aconnp->conn_netstack);
2491         ASSERT(eager->tcp_tcps == acceptor->tcp_tcps);
2492 
2493         aconnp->conn_cred = NULL;
2494 
2495         econnp->conn_zoneid = aconnp->conn_zoneid;
2496         econnp->conn_allzones = aconnp->conn_allzones;
2497 
2498         econnp->conn_mac_exempt = aconnp->conn_mac_exempt;
2499         aconnp->conn_mac_exempt = B_FALSE;
2500 
2501         ASSERT(aconnp->conn_peercred == NULL);
2502 
2503         /* Do the IPC initialization */
2504         CONN_INC_REF(econnp);
2505 
2506         econnp->conn_multicast_loop = aconnp->conn_multicast_loop;
2507         econnp->conn_af_isv6 = aconnp->conn_af_isv6;
2508         econnp->conn_pkt_isv6 = aconnp->conn_pkt_isv6;
2509 
2510         /* Done with old IPC. Drop its ref on its connp */
2511         CONN_DEC_REF(aconnp);
2512 }
2513 
2514 
2515 /*
2516  * Adapt to the information, such as rtt and rtt_sd, provided from the
2517  * ire cached in conn_cache_ire. If no ire cached, do a ire lookup.
2518  *
2519  * Checks for multicast and broadcast destination address.
2520  * Returns zero on failure; non-zero if ok.
2521  *
2522  * Note that the MSS calculation here is based on the info given in
2523  * the IRE.  We do not do any calculation based on TCP options.  They
2524  * will be handled in tcp_rput_other() and tcp_rput_data() when TCP
2525  * knows which options to use.
2526  *
2527  * Note on how TCP gets its parameters for a connection.
2528  *
2529  * When a tcp_t structure is allocated, it gets all the default parameters.
2530  * In tcp_adapt_ire(), it gets those metric parameters, like rtt, rtt_sd,
2531  * spipe, rpipe, ... from the route metrics.  Route metric overrides the
2532  * default.  But if there is an associated tcp_host_param, it will override
2533  * the metrics.
2534  *
2535  * An incoming SYN with a multicast or broadcast destination address, is dropped
2536  * in 1 of 2 places.
2537  *
2538  * 1. If the packet was received over the wire it is dropped in
2539  * ip_rput_process_broadcast()
2540  *
2541  * 2. If the packet was received through internal IP loopback, i.e. the packet
2542  * was generated and received on the same machine, it is dropped in
2543  * ip_wput_local()
2544  *
2545  * An incoming SYN with a multicast or broadcast source address is always
2546  * dropped in tcp_adapt_ire. The same logic in tcp_adapt_ire also serves to
2547  * reject an attempt to connect to a broadcast or multicast (destination)
2548  * address.
2549  */
2550 static int
2551 tcp_adapt_ire(tcp_t *tcp, mblk_t *ire_mp)
2552 {
2553         tcp_hsp_t       *hsp;
2554         ire_t           *ire;
2555         ire_t           *sire = NULL;
2556         iulp_t          *ire_uinfo = NULL;
2557         uint32_t        mss_max;
2558         uint32_t        mss;
2559         boolean_t       tcp_detached = TCP_IS_DETACHED(tcp);
2560         conn_t          *connp = tcp->tcp_connp;
2561         boolean_t       ire_cacheable = B_FALSE;
2562         zoneid_t        zoneid = connp->conn_zoneid;
2563         int             match_flags = MATCH_IRE_RECURSIVE | MATCH_IRE_DEFAULT |
2564             MATCH_IRE_SECATTR;
2565         ts_label_t      *tsl = crgetlabel(CONN_CRED(connp));
2566         ill_t           *ill = NULL;
2567         boolean_t       incoming = (ire_mp == NULL);
2568         tcp_stack_t     *tcps = tcp->tcp_tcps;
2569         ip_stack_t      *ipst = tcps->tcps_netstack->netstack_ip;
2570 
2571         ASSERT(connp->conn_ire_cache == NULL);
2572 
2573         if (tcp->tcp_ipversion == IPV4_VERSION) {
2574 
2575                 if (CLASSD(tcp->tcp_connp->conn_rem)) {
2576                         BUMP_MIB(&ipst->ips_ip_mib, ipIfStatsInDiscards);
2577                         return (0);
2578                 }
2579                 /*
2580                  * If IP_NEXTHOP is set, then look for an IRE_CACHE
2581                  * for the destination with the nexthop as gateway.
2582                  * ire_ctable_lookup() is used because this particular
2583                  * ire, if it exists, will be marked private.
2584                  * If that is not available, use the interface ire
2585                  * for the nexthop.
2586                  *
2587                  * TSol: tcp_update_label will detect label mismatches based
2588                  * only on the destination's label, but that would not
2589                  * detect label mismatches based on the security attributes
2590                  * of routes or next hop gateway. Hence we need to pass the
2591                  * label to ire_ftable_lookup below in order to locate the
2592                  * right prefix (and/or) ire cache. Similarly we also need
2593                  * pass the label to the ire_cache_lookup below to locate
2594                  * the right ire that also matches on the label.
2595                  */
2596                 if (tcp->tcp_connp->conn_nexthop_set) {
2597                         ire = ire_ctable_lookup(tcp->tcp_connp->conn_rem,
2598                             tcp->tcp_connp->conn_nexthop_v4, 0, NULL, zoneid,
2599                             tsl, MATCH_IRE_MARK_PRIVATE_ADDR | MATCH_IRE_GW,
2600                             ipst);
2601                         if (ire == NULL) {
2602                                 ire = ire_ftable_lookup(
2603                                     tcp->tcp_connp->conn_nexthop_v4,
2604                                     0, 0, IRE_INTERFACE, NULL, NULL, zoneid, 0,
2605                                     tsl, match_flags, ipst);
2606                                 if (ire == NULL)
2607                                         return (0);
2608                         } else {
2609                                 ire_uinfo = &ire->ire_uinfo;
2610                         }
2611                 } else {
2612                         ire = ire_cache_lookup(tcp->tcp_connp->conn_rem,
2613                             zoneid, tsl, ipst);
2614                         if (ire != NULL) {
2615                                 ire_cacheable = B_TRUE;
2616                                 ire_uinfo = (ire_mp != NULL) ?
2617                                     &((ire_t *)ire_mp->b_rptr)->ire_uinfo:
2618                                     &ire->ire_uinfo;
2619 
2620                         } else {
2621                                 if (ire_mp == NULL) {
2622                                         ire = ire_ftable_lookup(
2623                                             tcp->tcp_connp->conn_rem,
2624                                             0, 0, 0, NULL, &sire, zoneid, 0,
2625                                             tsl, (MATCH_IRE_RECURSIVE |
2626                                             MATCH_IRE_DEFAULT), ipst);
2627                                         if (ire == NULL)
2628                                                 return (0);
2629                                         ire_uinfo = (sire != NULL) ?
2630                                             &sire->ire_uinfo :
2631                                             &ire->ire_uinfo;
2632                                 } else {
2633                                         ire = (ire_t *)ire_mp->b_rptr;
2634                                         ire_uinfo =
2635                                             &((ire_t *)
2636                                             ire_mp->b_rptr)->ire_uinfo;
2637                                 }
2638                         }
2639                 }
2640                 ASSERT(ire != NULL);
2641 
2642                 if ((ire->ire_src_addr == INADDR_ANY) ||
2643                     (ire->ire_type & IRE_BROADCAST)) {
2644                         /*
2645                          * ire->ire_mp is non null when ire_mp passed in is used
2646                          * ire->ire_mp is set in ip_bind_insert_ire[_v6]().
2647                          */
2648                         if (ire->ire_mp == NULL)
2649                                 ire_refrele(ire);
2650                         if (sire != NULL)
2651                                 ire_refrele(sire);
2652                         return (0);
2653                 }
2654 
2655                 if (tcp->tcp_ipha->ipha_src == INADDR_ANY) {
2656                         ipaddr_t src_addr;
2657 
2658                         /*
2659                          * ip_bind_connected() has stored the correct source
2660                          * address in conn_src.
2661                          */
2662                         src_addr = tcp->tcp_connp->conn_src;
2663                         tcp->tcp_ipha->ipha_src = src_addr;
2664                         /*
2665                          * Copy of the src addr. in tcp_t is needed
2666                          * for the lookup funcs.
2667                          */
2668                         IN6_IPADDR_TO_V4MAPPED(src_addr, &tcp->tcp_ip_src_v6);
2669                 }
2670                 /*
2671                  * Set the fragment bit so that IP will tell us if the MTU
2672                  * should change. IP tells us the latest setting of
2673                  * ip_path_mtu_discovery through ire_frag_flag.
2674                  */
2675                 if (ipst->ips_ip_path_mtu_discovery) {
2676                         tcp->tcp_ipha->ipha_fragment_offset_and_flags =
2677                             htons(IPH_DF);
2678                 }
2679                 /*
2680                  * If ire_uinfo is NULL, this is the IRE_INTERFACE case
2681                  * for IP_NEXTHOP. No cache ire has been found for the
2682                  * destination and we are working with the nexthop's
2683                  * interface ire. Since we need to forward all packets
2684                  * to the nexthop first, we "blindly" set tcp_localnet
2685                  * to false, eventhough the destination may also be
2686                  * onlink.
2687                  */
2688                 if (ire_uinfo == NULL)
2689                         tcp->tcp_localnet = 0;
2690                 else
2691                         tcp->tcp_localnet = (ire->ire_gateway_addr == 0);
2692         } else {
2693                 /*
2694                  * For incoming connection ire_mp = NULL
2695                  * For outgoing connection ire_mp != NULL
2696                  * Technically we should check conn_incoming_ill
2697                  * when ire_mp is NULL and conn_outgoing_ill when
2698                  * ire_mp is non-NULL. But this is performance
2699                  * critical path and for IPV*_BOUND_IF, outgoing
2700                  * and incoming ill are always set to the same value.
2701                  */
2702                 ill_t   *dst_ill = NULL;
2703                 ipif_t  *dst_ipif = NULL;
2704 
2705                 ASSERT(connp->conn_outgoing_ill == connp->conn_incoming_ill);
2706 
2707                 if (connp->conn_outgoing_ill != NULL) {
2708                         /* Outgoing or incoming path */
2709                         int   err;
2710 
2711                         dst_ill = conn_get_held_ill(connp,
2712                             &connp->conn_outgoing_ill, &err);
2713                         if (err == ILL_LOOKUP_FAILED || dst_ill == NULL) {
2714                                 ip1dbg(("tcp_adapt_ire: ill_lookup failed\n"));
2715                                 return (0);
2716                         }
2717                         match_flags |= MATCH_IRE_ILL;
2718                         dst_ipif = dst_ill->ill_ipif;
2719                 }
2720                 ire = ire_ctable_lookup_v6(&tcp->tcp_connp->conn_remv6,
2721                     0, 0, dst_ipif, zoneid, tsl, match_flags, ipst);
2722 
2723                 if (ire != NULL) {
2724                         ire_cacheable = B_TRUE;
2725                         ire_uinfo = (ire_mp != NULL) ?
2726                             &((ire_t *)ire_mp->b_rptr)->ire_uinfo:
2727                             &ire->ire_uinfo;
2728                 } else {
2729                         if (ire_mp == NULL) {
2730                                 ire = ire_ftable_lookup_v6(
2731                                     &tcp->tcp_connp->conn_remv6,
2732                                     0, 0, 0, dst_ipif, &sire, zoneid,
2733                                     0, tsl, match_flags, ipst);
2734                                 if (ire == NULL) {
2735                                         if (dst_ill != NULL)
2736                                                 ill_refrele(dst_ill);
2737                                         return (0);
2738                                 }
2739                                 ire_uinfo = (sire != NULL) ? &sire->ire_uinfo :
2740                                     &ire->ire_uinfo;
2741                         } else {
2742                                 ire = (ire_t *)ire_mp->b_rptr;
2743                                 ire_uinfo =
2744                                     &((ire_t *)ire_mp->b_rptr)->ire_uinfo;
2745                         }
2746                 }
2747                 if (dst_ill != NULL)
2748                         ill_refrele(dst_ill);
2749 
2750                 ASSERT(ire != NULL);
2751                 ASSERT(ire_uinfo != NULL);
2752 
2753                 if (IN6_IS_ADDR_UNSPECIFIED(&ire->ire_src_addr_v6) ||
2754                     IN6_IS_ADDR_MULTICAST(&ire->ire_addr_v6)) {
2755                         /*
2756                          * ire->ire_mp is non null when ire_mp passed in is used
2757                          * ire->ire_mp is set in ip_bind_insert_ire[_v6]().
2758                          */
2759                         if (ire->ire_mp == NULL)
2760                                 ire_refrele(ire);
2761                         if (sire != NULL)
2762                                 ire_refrele(sire);
2763                         return (0);
2764                 }
2765 
2766                 if (IN6_IS_ADDR_UNSPECIFIED(&tcp->tcp_ip6h->ip6_src)) {
2767                         in6_addr_t      src_addr;
2768 
2769                         /*
2770                          * ip_bind_connected_v6() has stored the correct source
2771                          * address per IPv6 addr. selection policy in
2772                          * conn_src_v6.
2773                          */
2774                         src_addr = tcp->tcp_connp->conn_srcv6;
2775 
2776                         tcp->tcp_ip6h->ip6_src = src_addr;
2777                         /*
2778                          * Copy of the src addr. in tcp_t is needed
2779                          * for the lookup funcs.
2780                          */
2781                         tcp->tcp_ip_src_v6 = src_addr;
2782                         ASSERT(IN6_ARE_ADDR_EQUAL(&tcp->tcp_ip6h->ip6_src,
2783                             &connp->conn_srcv6));
2784                 }
2785                 tcp->tcp_localnet =
2786                     IN6_IS_ADDR_UNSPECIFIED(&ire->ire_gateway_addr_v6);
2787         }
2788 
2789         /*
2790          * This allows applications to fail quickly when connections are made
2791          * to dead hosts. Hosts can be labeled dead by adding a reject route
2792          * with both the RTF_REJECT and RTF_PRIVATE flags set.
2793          */
2794         if ((ire->ire_flags & RTF_REJECT) &&
2795             (ire->ire_flags & RTF_PRIVATE))
2796                 goto error;
2797 
2798         /*
2799          * Make use of the cached rtt and rtt_sd values to calculate the
2800          * initial RTO.  Note that they are already initialized in
2801          * tcp_init_values().
2802          * If ire_uinfo is NULL, i.e., we do not have a cache ire for
2803          * IP_NEXTHOP, but instead are using the interface ire for the
2804          * nexthop, then we do not use the ire_uinfo from that ire to
2805          * do any initializations.
2806          */
2807         if (ire_uinfo != NULL) {
2808                 if (ire_uinfo->iulp_rtt != 0) {
2809                         clock_t rto;
2810 
2811                         tcp->tcp_rtt_sa = ire_uinfo->iulp_rtt;
2812                         tcp->tcp_rtt_sd = ire_uinfo->iulp_rtt_sd;
2813                         rto = (tcp->tcp_rtt_sa >> 3) + tcp->tcp_rtt_sd +
2814                             tcps->tcps_rexmit_interval_extra +
2815                             (tcp->tcp_rtt_sa >> 5);
2816 
2817                         if (rto > tcps->tcps_rexmit_interval_max) {
2818                                 tcp->tcp_rto = tcps->tcps_rexmit_interval_max;
2819                         } else if (rto < tcps->tcps_rexmit_interval_min) {
2820                                 tcp->tcp_rto = tcps->tcps_rexmit_interval_min;
2821                         } else {
2822                                 tcp->tcp_rto = rto;
2823                         }
2824                 }
2825                 if (ire_uinfo->iulp_ssthresh != 0)
2826                         tcp->tcp_cwnd_ssthresh = ire_uinfo->iulp_ssthresh;
2827                 else
2828                         tcp->tcp_cwnd_ssthresh = TCP_MAX_LARGEWIN;
2829                 if (ire_uinfo->iulp_spipe > 0) {
2830                         tcp->tcp_xmit_hiwater = MIN(ire_uinfo->iulp_spipe,
2831                             tcps->tcps_max_buf);
2832                         if (tcps->tcps_snd_lowat_fraction != 0)
2833                                 tcp->tcp_xmit_lowater = tcp->tcp_xmit_hiwater /
2834                                     tcps->tcps_snd_lowat_fraction;
2835                         (void) tcp_maxpsz_set(tcp, B_TRUE);
2836                 }
2837                 /*
2838                  * Note that up till now, acceptor always inherits receive
2839                  * window from the listener.  But if there is a metrics
2840                  * associated with a host, we should use that instead of
2841                  * inheriting it from listener. Thus we need to pass this
2842                  * info back to the caller.
2843                  */
2844                 if (ire_uinfo->iulp_rpipe > 0) {
2845                         tcp->tcp_rwnd = MIN(ire_uinfo->iulp_rpipe,
2846                             tcps->tcps_max_buf);
2847                 }
2848 
2849                 if (ire_uinfo->iulp_rtomax > 0) {
2850                         tcp->tcp_second_timer_threshold =
2851                             ire_uinfo->iulp_rtomax;
2852                 }
2853 
2854                 /*
2855                  * Use the metric option settings, iulp_tstamp_ok and
2856                  * iulp_wscale_ok, only for active open. What this means
2857                  * is that if the other side uses timestamp or window
2858                  * scale option, TCP will also use those options. That
2859                  * is for passive open.  If the application sets a
2860                  * large window, window scale is enabled regardless of
2861                  * the value in iulp_wscale_ok.  This is the behavior
2862                  * since 2.6.  So we keep it.
2863                  * The only case left in passive open processing is the
2864                  * check for SACK.
2865                  * For ECN, it should probably be like SACK.  But the
2866                  * current value is binary, so we treat it like the other
2867                  * cases.  The metric only controls active open.For passive
2868                  * open, the ndd param, tcp_ecn_permitted, controls the
2869                  * behavior.
2870                  */
2871                 if (!tcp_detached) {
2872                         /*
2873                          * The if check means that the following can only
2874                          * be turned on by the metrics only IRE, but not off.
2875                          */
2876                         if (ire_uinfo->iulp_tstamp_ok)
2877                                 tcp->tcp_snd_ts_ok = B_TRUE;
2878                         if (ire_uinfo->iulp_wscale_ok)
2879                                 tcp->tcp_snd_ws_ok = B_TRUE;
2880                         if (ire_uinfo->iulp_sack == 2)
2881                                 tcp->tcp_snd_sack_ok = B_TRUE;
2882                         if (ire_uinfo->iulp_ecn_ok)
2883                                 tcp->tcp_ecn_ok = B_TRUE;
2884                 } else {
2885                         /*
2886                          * Passive open.
2887                          *
2888                          * As above, the if check means that SACK can only be
2889                          * turned on by the metric only IRE.
2890                          */
2891                         if (ire_uinfo->iulp_sack > 0) {
2892                                 tcp->tcp_snd_sack_ok = B_TRUE;
2893                         }
2894                 }
2895         }
2896 
2897 
2898         /*
2899          * XXX: Note that currently, ire_max_frag can be as small as 68
2900          * because of PMTUd.  So tcp_mss may go to negative if combined
2901          * length of all those options exceeds 28 bytes.  But because
2902          * of the tcp_mss_min check below, we may not have a problem if
2903          * tcp_mss_min is of a reasonable value.  The default is 1 so
2904          * the negative problem still exists.  And the check defeats PMTUd.
2905          * In fact, if PMTUd finds that the MSS should be smaller than
2906          * tcp_mss_min, TCP should turn off PMUTd and use the tcp_mss_min
2907          * value.
2908          *
2909          * We do not deal with that now.  All those problems related to
2910          * PMTUd will be fixed later.
2911          */
2912         ASSERT(ire->ire_max_frag != 0);
2913         mss = tcp->tcp_if_mtu = ire->ire_max_frag;
2914         if (tcp->tcp_ipp_fields & IPPF_USE_MIN_MTU) {
2915                 if (tcp->tcp_ipp_use_min_mtu == IPV6_USE_MIN_MTU_NEVER) {
2916                         mss = MIN(mss, IPV6_MIN_MTU);
2917                 }
2918         }
2919 
2920         /* Sanity check for MSS value. */
2921         if (tcp->tcp_ipversion == IPV4_VERSION)
2922                 mss_max = tcps->tcps_mss_max_ipv4;
2923         else
2924                 mss_max = tcps->tcps_mss_max_ipv6;
2925 
2926         if (tcp->tcp_ipversion == IPV6_VERSION &&
2927             (ire->ire_frag_flag & IPH_FRAG_HDR)) {
2928                 /*
2929                  * After receiving an ICMPv6 "packet too big" message with a
2930                  * MTU < 1280, and for multirouted IPv6 packets, the IP layer
2931                  * will insert a 8-byte fragment header in every packet; we
2932                  * reduce the MSS by that amount here.
2933                  */
2934                 mss -= sizeof (ip6_frag_t);
2935         }
2936 
2937         if (tcp->tcp_ipsec_overhead == 0)
2938                 tcp->tcp_ipsec_overhead = conn_ipsec_length(connp);
2939 
2940         mss -= tcp->tcp_ipsec_overhead;
2941 
2942         if (mss < tcps->tcps_mss_min)
2943                 mss = tcps->tcps_mss_min;
2944         if (mss > mss_max)
2945                 mss = mss_max;
2946 
2947         /* Note that this is the maximum MSS, excluding all options. */
2948         tcp->tcp_mss = mss;
2949 
2950         /*
2951          * Initialize the ISS here now that we have the full connection ID.
2952          * The RFC 1948 method of initial sequence number generation requires
2953          * knowledge of the full connection ID before setting the ISS.
2954          */
2955 
2956         tcp_iss_init(tcp);
2957 
2958         if (ire->ire_type & (IRE_LOOPBACK | IRE_LOCAL))
2959                 tcp->tcp_loopback = B_TRUE;
2960 
2961         if (tcp->tcp_ipversion == IPV4_VERSION) {
2962                 hsp = tcp_hsp_lookup(tcp->tcp_remote, tcps);
2963         } else {
2964                 hsp = tcp_hsp_lookup_ipv6(&tcp->tcp_remote_v6, tcps);
2965         }
2966 
2967         if (hsp != NULL) {
2968                 /* Only modify if we're going to make them bigger */
2969                 if (hsp->tcp_hsp_sendspace > tcp->tcp_xmit_hiwater) {
2970                         tcp->tcp_xmit_hiwater = hsp->tcp_hsp_sendspace;
2971                         if (tcps->tcps_snd_lowat_fraction != 0)
2972                                 tcp->tcp_xmit_lowater = tcp->tcp_xmit_hiwater /
2973                                     tcps->tcps_snd_lowat_fraction;
2974                 }
2975 
2976                 if (hsp->tcp_hsp_recvspace > tcp->tcp_rwnd) {
2977                         tcp->tcp_rwnd = hsp->tcp_hsp_recvspace;
2978                 }
2979 
2980                 /* Copy timestamp flag only for active open */
2981                 if (!tcp_detached)
2982                         tcp->tcp_snd_ts_ok = hsp->tcp_hsp_tstamp;
2983         }
2984 
2985         if (sire != NULL)
2986                 IRE_REFRELE(sire);
2987 
2988         /*
2989          * If we got an IRE_CACHE and an ILL, go through their properties;
2990          * otherwise, this is deferred until later when we have an IRE_CACHE.
2991          */
2992         if (tcp->tcp_loopback ||
2993             (ire_cacheable && (ill = ire_to_ill(ire)) != NULL)) {
2994                 /*
2995                  * For incoming, see if this tcp may be MDT-capable.  For
2996                  * outgoing, this process has been taken care of through
2997                  * tcp_rput_other.
2998                  */
2999                 tcp_ire_ill_check(tcp, ire, ill, incoming);
3000                 tcp->tcp_ire_ill_check_done = B_TRUE;
3001         }
3002 
3003         mutex_enter(&connp->conn_lock);
3004         /*
3005          * Make sure that conn is not marked incipient
3006          * for incoming connections. A blind
3007          * removal of incipient flag is cheaper than
3008          * check and removal.
3009          */
3010         connp->conn_state_flags &= ~CONN_INCIPIENT;
3011 
3012         /*
3013          * Must not cache forwarding table routes
3014          * or recache an IRE after the conn_t has
3015          * had conn_ire_cache cleared and is flagged
3016          * unusable, (see the CONN_CACHE_IRE() macro).
3017          */
3018         if (ire_cacheable && CONN_CACHE_IRE(connp)) {
3019                 rw_enter(&ire->ire_bucket->irb_lock, RW_READER);
3020                 if (!(ire->ire_marks & IRE_MARK_CONDEMNED)) {
3021                         connp->conn_ire_cache = ire;
3022                         IRE_UNTRACE_REF(ire);
3023                         rw_exit(&ire->ire_bucket->irb_lock);
3024                         mutex_exit(&connp->conn_lock);
3025                         return (1);
3026                 }
3027                 rw_exit(&ire->ire_bucket->irb_lock);
3028         }
3029         mutex_exit(&connp->conn_lock);
3030 
3031         if (ire->ire_mp == NULL)
3032                 ire_refrele(ire);
3033         return (1);
3034 
3035 error:
3036         if (ire->ire_mp == NULL)
3037                 ire_refrele(ire);
3038         if (sire != NULL)
3039                 ire_refrele(sire);
3040         return (0);
3041 }
3042 
3043 /*
3044  * tcp_bind is called (holding the writer lock) by tcp_wput_proto to process a
3045  * O_T_BIND_REQ/T_BIND_REQ message.
3046  */
3047 static void
3048 tcp_bind(tcp_t *tcp, mblk_t *mp)
3049 {
3050         sin_t   *sin;
3051         sin6_t  *sin6;
3052         mblk_t  *mp1;
3053         in_port_t requested_port;
3054         in_port_t allocated_port;
3055         struct T_bind_req *tbr;
3056         boolean_t       bind_to_req_port_only;
3057         boolean_t       backlog_update = B_FALSE;
3058         boolean_t       user_specified;
3059         in6_addr_t      v6addr;
3060         ipaddr_t        v4addr;
3061         uint_t  origipversion;
3062         int     err;
3063         queue_t *q = tcp->tcp_wq;
3064         conn_t  *connp = tcp->tcp_connp;
3065         mlp_type_t addrtype, mlptype;
3066         zone_t  *zone;
3067         cred_t  *cr;
3068         in_port_t mlp_port;
3069         tcp_stack_t     *tcps = tcp->tcp_tcps;
3070 
3071         ASSERT((uintptr_t)(mp->b_wptr - mp->b_rptr) <= (uintptr_t)INT_MAX);
3072         if ((mp->b_wptr - mp->b_rptr) < sizeof (*tbr)) {
3073                 if (tcp->tcp_debug) {
3074                         (void) strlog(TCP_MOD_ID, 0, 1, SL_ERROR|SL_TRACE,
3075                             "tcp_bind: bad req, len %u",
3076                             (uint_t)(mp->b_wptr - mp->b_rptr));
3077                 }
3078                 tcp_err_ack(tcp, mp, TPROTO, 0);
3079                 return;
3080         }
3081         /* Make sure the largest address fits */
3082         mp1 = reallocb(mp, sizeof (struct T_bind_ack) + sizeof (sin6_t) + 1, 1);
3083         if (mp1 == NULL) {
3084                 tcp_err_ack(tcp, mp, TSYSERR, ENOMEM);
3085                 return;
3086         }
3087         mp = mp1;
3088         tbr = (struct T_bind_req *)mp->b_rptr;
3089         if (tcp->tcp_state >= TCPS_BOUND) {
3090                 if ((tcp->tcp_state == TCPS_BOUND ||
3091                     tcp->tcp_state == TCPS_LISTEN) &&
3092                     tcp->tcp_conn_req_max != tbr->CONIND_number &&
3093                     tbr->CONIND_number > 0) {
3094                         /*
3095                          * Handle listen() increasing CONIND_number.
3096                          * This is more "liberal" then what the TPI spec
3097                          * requires but is needed to avoid a t_unbind
3098                          * when handling listen() since the port number
3099                          * might be "stolen" between the unbind and bind.
3100                          */
3101                         backlog_update = B_TRUE;
3102                         goto do_bind;
3103                 }
3104                 if (tcp->tcp_debug) {
3105                         (void) strlog(TCP_MOD_ID, 0, 1, SL_ERROR|SL_TRACE,
3106                             "tcp_bind: bad state, %d", tcp->tcp_state);
3107                 }
3108                 tcp_err_ack(tcp, mp, TOUTSTATE, 0);
3109                 return;
3110         }
3111         origipversion = tcp->tcp_ipversion;
3112 
3113         switch (tbr->ADDR_length) {
3114         case 0:                 /* request for a generic port */
3115                 tbr->ADDR_offset = sizeof (struct T_bind_req);
3116                 if (tcp->tcp_family == AF_INET) {
3117                         tbr->ADDR_length = sizeof (sin_t);
3118                         sin = (sin_t *)&tbr[1];
3119                         *sin = sin_null;
3120                         sin->sin_family = AF_INET;
3121                         mp->b_wptr = (uchar_t *)&sin[1];
3122                         tcp->tcp_ipversion = IPV4_VERSION;
3123                         IN6_IPADDR_TO_V4MAPPED(INADDR_ANY, &v6addr);
3124                 } else {
3125                         ASSERT(tcp->tcp_family == AF_INET6);
3126                         tbr->ADDR_length = sizeof (sin6_t);
3127                         sin6 = (sin6_t *)&tbr[1];
3128                         *sin6 = sin6_null;
3129                         sin6->sin6_family = AF_INET6;
3130                         mp->b_wptr = (uchar_t *)&sin6[1];
3131                         tcp->tcp_ipversion = IPV6_VERSION;
3132                         V6_SET_ZERO(v6addr);
3133                 }
3134                 requested_port = 0;
3135                 break;
3136 
3137         case sizeof (sin_t):    /* Complete IPv4 address */
3138                 sin = (sin_t *)mi_offset_param(mp, tbr->ADDR_offset,
3139                     sizeof (sin_t));
3140                 if (sin == NULL || !OK_32PTR((char *)sin)) {
3141                         if (tcp->tcp_debug) {
3142                                 (void) strlog(TCP_MOD_ID, 0, 1,
3143                                     SL_ERROR|SL_TRACE,
3144                                     "tcp_bind: bad address parameter, "
3145                                     "offset %d, len %d",
3146                                     tbr->ADDR_offset, tbr->ADDR_length);
3147                         }
3148                         tcp_err_ack(tcp, mp, TPROTO, 0);
3149                         return;
3150                 }
3151                 /*
3152                  * With sockets sockfs will accept bogus sin_family in
3153                  * bind() and replace it with the family used in the socket
3154                  * call.
3155                  */
3156                 if (sin->sin_family != AF_INET ||
3157                     tcp->tcp_family != AF_INET) {
3158                         tcp_err_ack(tcp, mp, TSYSERR, EAFNOSUPPORT);
3159                         return;
3160                 }
3161                 requested_port = ntohs(sin->sin_port);
3162                 tcp->tcp_ipversion = IPV4_VERSION;
3163                 v4addr = sin->sin_addr.s_addr;
3164                 IN6_IPADDR_TO_V4MAPPED(v4addr, &v6addr);
3165                 break;
3166 
3167         case sizeof (sin6_t): /* Complete IPv6 address */
3168                 sin6 = (sin6_t *)mi_offset_param(mp,
3169                     tbr->ADDR_offset, sizeof (sin6_t));
3170                 if (sin6 == NULL || !OK_32PTR((char *)sin6)) {
3171                         if (tcp->tcp_debug) {
3172                                 (void) strlog(TCP_MOD_ID, 0, 1,
3173                                     SL_ERROR|SL_TRACE,
3174                                     "tcp_bind: bad IPv6 address parameter, "
3175                                     "offset %d, len %d", tbr->ADDR_offset,
3176                                     tbr->ADDR_length);
3177                         }
3178                         tcp_err_ack(tcp, mp, TSYSERR, EINVAL);
3179                         return;
3180                 }
3181                 if (sin6->sin6_family != AF_INET6 ||
3182                     tcp->tcp_family != AF_INET6) {
3183                         tcp_err_ack(tcp, mp, TSYSERR, EAFNOSUPPORT);
3184                         return;
3185                 }
3186                 requested_port = ntohs(sin6->sin6_port);
3187                 tcp->tcp_ipversion = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr) ?
3188                     IPV4_VERSION : IPV6_VERSION;
3189                 v6addr = sin6->sin6_addr;
3190                 break;
3191 
3192         default:
3193                 if (tcp->tcp_debug) {
3194                         (void) strlog(TCP_MOD_ID, 0, 1, SL_ERROR|SL_TRACE,
3195                             "tcp_bind: bad address length, %d",
3196                             tbr->ADDR_length);
3197                 }
3198                 tcp_err_ack(tcp, mp, TBADADDR, 0);
3199                 return;
3200         }
3201         tcp->tcp_bound_source_v6 = v6addr;
3202 
3203         /* Check for change in ipversion */
3204         if (origipversion != tcp->tcp_ipversion) {
3205                 ASSERT(tcp->tcp_family == AF_INET6);
3206                 err = tcp->tcp_ipversion == IPV6_VERSION ?
3207                     tcp_header_init_ipv6(tcp) : tcp_header_init_ipv4(tcp);
3208                 if (err) {
3209                         tcp_err_ack(tcp, mp, TSYSERR, ENOMEM);
3210                         return;
3211                 }
3212         }
3213 
3214         /*
3215          * Initialize family specific fields. Copy of the src addr.
3216          * in tcp_t is needed for the lookup funcs.
3217          */
3218         if (tcp->tcp_ipversion == IPV6_VERSION) {
3219                 tcp->tcp_ip6h->ip6_src = v6addr;
3220         } else {
3221                 IN6_V4MAPPED_TO_IPADDR(&v6addr, tcp->tcp_ipha->ipha_src);
3222         }
3223         tcp->tcp_ip_src_v6 = v6addr;
3224 
3225         /*
3226          * For O_T_BIND_REQ:
3227          * Verify that the target port/addr is available, or choose
3228          * another.
3229          * For  T_BIND_REQ:
3230          * Verify that the target port/addr is available or fail.
3231          * In both cases when it succeeds the tcp is inserted in the
3232          * bind hash table. This ensures that the operation is atomic
3233          * under the lock on the hash bucket.
3234          */
3235         bind_to_req_port_only = requested_port != 0 &&
3236             tbr->PRIM_type != O_T_BIND_REQ;
3237         /*
3238          * Get a valid port (within the anonymous range and should not
3239          * be a privileged one) to use if the user has not given a port.
3240          * If multiple threads are here, they may all start with
3241          * with the same initial port. But, it should be fine as long as
3242          * tcp_bindi will ensure that no two threads will be assigned
3243          * the same port.
3244          *
3245          * NOTE: XXX If a privileged process asks for an anonymous port, we
3246          * still check for ports only in the range > tcp_smallest_non_priv_port,
3247          * unless TCP_ANONPRIVBIND option is set.
3248          */
3249         mlptype = mlptSingle;
3250         mlp_port = requested_port;
3251         if (requested_port == 0) {
3252                 requested_port = tcp->tcp_anon_priv_bind ?
3253                     tcp_get_next_priv_port(tcp) :
3254                     tcp_update_next_port(tcps->tcps_next_port_to_try,
3255                     tcp, B_TRUE);
3256                 if (requested_port == 0) {
3257                         tcp_err_ack(tcp, mp, TNOADDR, 0);
3258                         return;
3259                 }
3260                 user_specified = B_FALSE;
3261 
3262                 /*
3263                  * If the user went through one of the RPC interfaces to create
3264                  * this socket and RPC is MLP in this zone, then give him an
3265                  * anonymous MLP.
3266                  */
3267                 cr = DB_CREDDEF(mp, tcp->tcp_cred);
3268                 if (connp->conn_anon_mlp && is_system_labeled()) {
3269                         zone = crgetzone(cr);
3270                         addrtype = tsol_mlp_addr_type(zone->zone_id,
3271                             IPV6_VERSION, &v6addr,
3272                             tcps->tcps_netstack->netstack_ip);
3273                         if (addrtype == mlptSingle) {
3274                                 tcp_err_ack(tcp, mp, TNOADDR, 0);
3275                                 return;
3276                         }
3277                         mlptype = tsol_mlp_port_type(zone, IPPROTO_TCP,
3278                             PMAPPORT, addrtype);
3279                         mlp_port = PMAPPORT;
3280                 }
3281         } else {
3282                 int i;
3283                 boolean_t priv = B_FALSE;
3284 
3285                 /*
3286                  * If the requested_port is in the well-known privileged range,
3287                  * verify that the stream was opened by a privileged user.
3288                  * Note: No locks are held when inspecting tcp_g_*epriv_ports
3289                  * but instead the code relies on:
3290                  * - the fact that the address of the array and its size never
3291                  *   changes
3292                  * - the atomic assignment of the elements of the array
3293                  */
3294                 cr = DB_CREDDEF(mp, tcp->tcp_cred);
3295                 if (requested_port < tcps->tcps_smallest_nonpriv_port) {
3296                         priv = B_TRUE;
3297                 } else {
3298                         for (i = 0; i < tcps->tcps_g_num_epriv_ports; i++) {
3299                                 if (requested_port ==
3300                                     tcps->tcps_g_epriv_ports[i]) {
3301                                         priv = B_TRUE;
3302                                         break;
3303                                 }
3304                         }
3305                 }
3306                 if (priv) {
3307                         if (secpolicy_net_privaddr(cr, requested_port,
3308                             IPPROTO_TCP) != 0) {
3309                                 if (tcp->tcp_debug) {
3310                                         (void) strlog(TCP_MOD_ID, 0, 1,
3311                                             SL_ERROR|SL_TRACE,
3312                                             "tcp_bind: no priv for port %d",
3313                                             requested_port);
3314                                 }
3315                                 tcp_err_ack(tcp, mp, TACCES, 0);
3316                                 return;
3317                         }
3318                 }
3319                 user_specified = B_TRUE;
3320 
3321                 if (is_system_labeled()) {
3322                         zone = crgetzone(cr);
3323                         addrtype = tsol_mlp_addr_type(zone->zone_id,
3324                             IPV6_VERSION, &v6addr,
3325                             tcps->tcps_netstack->netstack_ip);
3326                         if (addrtype == mlptSingle) {
3327                                 tcp_err_ack(tcp, mp, TNOADDR, 0);
3328                                 return;
3329                         }
3330                         mlptype = tsol_mlp_port_type(zone, IPPROTO_TCP,
3331                             requested_port, addrtype);
3332                 }
3333         }
3334 
3335         if (mlptype != mlptSingle) {
3336                 if (secpolicy_net_bindmlp(cr) != 0) {
3337                         if (tcp->tcp_debug) {
3338                                 (void) strlog(TCP_MOD_ID, 0, 1,
3339                                     SL_ERROR|SL_TRACE,
3340                                     "tcp_bind: no priv for multilevel port %d",
3341                                     requested_port);
3342                         }
3343                         tcp_err_ack(tcp, mp, TACCES, 0);
3344                         return;
3345                 }
3346 
3347                 /*
3348                  * If we're specifically binding a shared IP address and the
3349                  * port is MLP on shared addresses, then check to see if this
3350                  * zone actually owns the MLP.  Reject if not.
3351                  */
3352                 if (mlptype == mlptShared && addrtype == mlptShared) {
3353                         /*
3354                          * No need to handle exclusive-stack zones since
3355                          * ALL_ZONES only applies to the shared stack.
3356                          */
3357                         zoneid_t mlpzone;
3358 
3359                         mlpzone = tsol_mlp_findzone(IPPROTO_TCP,
3360                             htons(mlp_port));
3361                         if (connp->conn_zoneid != mlpzone) {
3362                                 if (tcp->tcp_debug) {
3363                                         (void) strlog(TCP_MOD_ID, 0, 1,
3364                                             SL_ERROR|SL_TRACE,
3365                                             "tcp_bind: attempt to bind port "
3366                                             "%d on shared addr in zone %d "
3367                                             "(should be %d)",
3368                                             mlp_port, connp->conn_zoneid,
3369                                             mlpzone);
3370                                 }
3371                                 tcp_err_ack(tcp, mp, TACCES, 0);
3372                                 return;
3373                         }
3374                 }
3375 
3376                 if (!user_specified) {
3377                         err = tsol_mlp_anon(zone, mlptype, connp->conn_ulp,
3378                             requested_port, B_TRUE);
3379                         if (err != 0) {
3380                                 if (tcp->tcp_debug) {
3381                                         (void) strlog(TCP_MOD_ID, 0, 1,
3382                                             SL_ERROR|SL_TRACE,
3383                                             "tcp_bind: cannot establish anon "
3384                                             "MLP for port %d",
3385                                             requested_port);
3386                                 }
3387                                 tcp_err_ack(tcp, mp, TSYSERR, err);
3388                                 return;
3389                         }
3390                         connp->conn_anon_port = B_TRUE;
3391                 }
3392                 connp->conn_mlp_type = mlptype;
3393         }
3394 
3395         allocated_port = tcp_bindi(tcp, requested_port, &v6addr,
3396             tcp->tcp_reuseaddr, B_FALSE, bind_to_req_port_only, user_specified);
3397 
3398         if (allocated_port == 0) {
3399                 connp->conn_mlp_type = mlptSingle;
3400                 if (connp->conn_anon_port) {
3401                         connp->conn_anon_port = B_FALSE;
3402                         (void) tsol_mlp_anon(zone, mlptype, connp->conn_ulp,
3403                             requested_port, B_FALSE);
3404                 }
3405                 if (bind_to_req_port_only) {
3406                         if (tcp->tcp_debug) {
3407                                 (void) strlog(TCP_MOD_ID, 0, 1,
3408                                     SL_ERROR|SL_TRACE,
3409                                     "tcp_bind: requested addr busy");
3410                         }
3411                         tcp_err_ack(tcp, mp, TADDRBUSY, 0);
3412                 } else {
3413                         /* If we are out of ports, fail the bind. */
3414                         if (tcp->tcp_debug) {
3415                                 (void) strlog(TCP_MOD_ID, 0, 1,
3416                                     SL_ERROR|SL_TRACE,
3417                                     "tcp_bind: out of ports?");
3418                         }
3419                         tcp_err_ack(tcp, mp, TNOADDR, 0);
3420                 }
3421                 return;
3422         }
3423         ASSERT(tcp->tcp_state == TCPS_BOUND);
3424 do_bind:
3425         if (!backlog_update) {
3426                 if (tcp->tcp_family == AF_INET)
3427                         sin->sin_port = htons(allocated_port);
3428                 else
3429                         sin6->sin6_port = htons(allocated_port);
3430         }
3431         if (tcp->tcp_family == AF_INET) {
3432                 if (tbr->CONIND_number != 0) {
3433                         mp1 = tcp_ip_bind_mp(tcp, tbr->PRIM_type,
3434                             sizeof (sin_t));
3435                 } else {
3436                         /* Just verify the local IP address */
3437                         mp1 = tcp_ip_bind_mp(tcp, tbr->PRIM_type, IP_ADDR_LEN);
3438                 }
3439         } else {
3440                 if (tbr->CONIND_number != 0) {
3441                         mp1 = tcp_ip_bind_mp(tcp, tbr->PRIM_type,
3442                             sizeof (sin6_t));
3443                 } else {
3444                         /* Just verify the local IP address */
3445                         mp1 = tcp_ip_bind_mp(tcp, tbr->PRIM_type,
3446                             IPV6_ADDR_LEN);
3447                 }
3448         }
3449         if (mp1 == NULL) {
3450                 if (connp->conn_anon_port) {
3451                         connp->conn_anon_port = B_FALSE;
3452                         (void) tsol_mlp_anon(zone, mlptype, connp->conn_ulp,
3453                             requested_port, B_FALSE);
3454                 }
3455                 connp->conn_mlp_type = mlptSingle;
3456                 tcp_err_ack(tcp, mp, TSYSERR, ENOMEM);
3457                 return;
3458         }
3459 
3460         tbr->PRIM_type = T_BIND_ACK;
3461         mp->b_datap->db_type = M_PCPROTO;
3462 
3463         /* Chain in the reply mp for tcp_rput() */
3464         mp1->b_cont = mp;
3465         mp = mp1;
3466 
3467         tcp->tcp_conn_req_max = tbr->CONIND_number;
3468         if (tcp->tcp_conn_req_max) {
3469                 if (tcp->tcp_conn_req_max < tcps->tcps_conn_req_min)
3470                         tcp->tcp_conn_req_max = tcps->tcps_conn_req_min;
3471                 if (tcp->tcp_conn_req_max > tcps->tcps_conn_req_max_q)
3472                         tcp->tcp_conn_req_max = tcps->tcps_conn_req_max_q;
3473                 /*
3474                  * If this is a listener, do not reset the eager list
3475                  * and other stuffs.  Note that we don't check if the
3476                  * existing eager list meets the new tcp_conn_req_max
3477                  * requirement.
3478                  */
3479                 if (tcp->tcp_state != TCPS_LISTEN) {
3480                         tcp->tcp_state = TCPS_LISTEN;
3481                         /* Initialize the chain. Don't need the eager_lock */
3482                         tcp->tcp_eager_next_q0 = tcp->tcp_eager_prev_q0 = tcp;
3483                         tcp->tcp_eager_next_drop_q0 = tcp;
3484                         tcp->tcp_eager_prev_drop_q0 = tcp;
3485                         tcp->tcp_second_ctimer_threshold =
3486                             tcps->tcps_ip_abort_linterval;
3487                 }
3488         }
3489 
3490         /*
3491          * We can call ip_bind directly which returns a T_BIND_ACK mp. The
3492          * processing continues in tcp_rput_other().
3493          *
3494          * We need to make sure that the conn_recv is set to a non-null
3495          * value before we insert the conn into the classifier table.
3496          * This is to avoid a race with an incoming packet which does an
3497          * ipcl_classify().
3498          */
3499         connp->conn_recv = tcp_conn_request;
3500         if (tcp->tcp_family == AF_INET6) {
3501                 ASSERT(tcp->tcp_connp->conn_af_isv6);
3502                 mp = ip_bind_v6(q, mp, tcp->tcp_connp, &tcp->tcp_sticky_ipp);
3503         } else {
3504                 ASSERT(!tcp->tcp_connp->conn_af_isv6);
3505                 mp = ip_bind_v4(q, mp, tcp->tcp_connp);
3506         }
3507         /*
3508          * If the bind cannot complete immediately
3509          * IP will arrange to call tcp_rput_other
3510          * when the bind completes.
3511          */
3512         if (mp != NULL) {
3513                 tcp_rput_other(tcp, mp);
3514         } else {
3515                 /*
3516                  * Bind will be resumed later. Need to ensure
3517                  * that conn doesn't disappear when that happens.
3518                  * This will be decremented in ip_resume_tcp_bind().
3519                  */
3520                 CONN_INC_REF(tcp->tcp_connp);
3521         }
3522 }
3523 
3524 
3525 /*
3526  * If the "bind_to_req_port_only" parameter is set, if the requested port
3527  * number is available, return it, If not return 0
3528  *
3529  * If "bind_to_req_port_only" parameter is not set and
3530  * If the requested port number is available, return it.  If not, return
3531  * the first anonymous port we happen across.  If no anonymous ports are
3532  * available, return 0. addr is the requested local address, if any.
3533  *
3534  * In either case, when succeeding update the tcp_t to record the port number
3535  * and insert it in the bind hash table.
3536  *
3537  * Note that TCP over IPv4 and IPv6 sockets can use the same port number
3538  * without setting SO_REUSEADDR. This is needed so that they
3539  * can be viewed as two independent transport protocols.
3540  */
3541 static in_port_t
3542 tcp_bindi(tcp_t *tcp, in_port_t port, const in6_addr_t *laddr,
3543     int reuseaddr, boolean_t quick_connect,
3544     boolean_t bind_to_req_port_only, boolean_t user_specified)
3545 {
3546         /* number of times we have run around the loop */
3547         int count = 0;
3548         /* maximum number of times to run around the loop */
3549         int loopmax;
3550         conn_t *connp = tcp->tcp_connp;
3551         zoneid_t zoneid = connp->conn_zoneid;
3552         tcp_stack_t     *tcps = tcp->tcp_tcps;
3553 
3554         /*
3555          * Lookup for free addresses is done in a loop and "loopmax"
3556          * influences how long we spin in the loop
3557          */
3558         if (bind_to_req_port_only) {
3559                 /*
3560                  * If the requested port is busy, don't bother to look
3561                  * for a new one. Setting loop maximum count to 1 has
3562                  * that effect.
3563                  */
3564                 loopmax = 1;
3565         } else {
3566                 /*
3567                  * If the requested port is busy, look for a free one
3568                  * in the anonymous port range.
3569                  * Set loopmax appropriately so that one does not look
3570                  * forever in the case all of the anonymous ports are in use.
3571                  */
3572                 if (tcp->tcp_anon_priv_bind) {
3573                         /*
3574                          * loopmax =
3575                          *      (IPPORT_RESERVED-1) - tcp_min_anonpriv_port + 1
3576                          */
3577                         loopmax = IPPORT_RESERVED -
3578                             tcps->tcps_min_anonpriv_port;
3579                 } else {
3580                         loopmax = (tcps->tcps_largest_anon_port -
3581                             tcps->tcps_smallest_anon_port + 1);
3582                 }
3583         }
3584         do {
3585                 uint16_t        lport;
3586                 tf_t            *tbf;
3587                 tcp_t           *ltcp;
3588                 conn_t          *lconnp;
3589 
3590                 lport = htons(port);
3591 
3592                 /*
3593                  * Ensure that the tcp_t is not currently in the bind hash.
3594                  * Hold the lock on the hash bucket to ensure that
3595                  * the duplicate check plus the insertion is an atomic
3596                  * operation.
3597                  *
3598                  * This function does an inline lookup on the bind hash list
3599                  * Make sure that we access only members of tcp_t
3600                  * and that we don't look at tcp_tcp, since we are not
3601                  * doing a CONN_INC_REF.
3602                  */
3603                 tcp_bind_hash_remove(tcp);
3604                 tbf = &tcps->tcps_bind_fanout[TCP_BIND_HASH(lport)];
3605                 mutex_enter(&tbf->tf_lock);
3606                 for (ltcp = tbf->tf_tcp; ltcp != NULL;
3607                     ltcp = ltcp->tcp_bind_hash) {
3608                         boolean_t not_socket;
3609                         boolean_t exclbind;
3610 
3611                         if (lport != ltcp->tcp_lport)
3612                                 continue;
3613 
3614                         lconnp = ltcp->tcp_connp;
3615 
3616                         /*
3617                          * On a labeled system, we must treat bindings to ports
3618                          * on shared IP addresses by sockets with MAC exemption
3619                          * privilege as being in all zones, as there's
3620                          * otherwise no way to identify the right receiver.
3621                          */
3622                         if (!(IPCL_ZONE_MATCH(ltcp->tcp_connp, zoneid) ||
3623                             IPCL_ZONE_MATCH(connp,
3624                             ltcp->tcp_connp->conn_zoneid)) &&
3625                             !lconnp->conn_mac_exempt &&
3626                             !connp->conn_mac_exempt)
3627                                 continue;
3628 
3629                         /*
3630                          * If TCP_EXCLBIND is set for either the bound or
3631                          * binding endpoint, the semantics of bind
3632                          * is changed according to the following.
3633                          *
3634                          * spec = specified address (v4 or v6)
3635                          * unspec = unspecified address (v4 or v6)
3636                          * A = specified addresses are different for endpoints
3637                          *
3638                          * bound        bind to         allowed
3639                          * -------------------------------------
3640                          * unspec       unspec          no
3641                          * unspec       spec            no
3642                          * spec         unspec          no
3643                          * spec         spec            yes if A
3644                          *
3645                          * For labeled systems, SO_MAC_EXEMPT behaves the same
3646                          * as TCP_EXCLBIND, except that zoneid is ignored.
3647                          *
3648                          * Note:
3649                          *
3650                          * 1. Because of TLI semantics, an endpoint can go
3651                          * back from, say TCP_ESTABLISHED to TCPS_LISTEN or
3652                          * TCPS_BOUND, depending on whether it is originally
3653                          * a listener or not.  That is why we need to check
3654                          * for states greater than or equal to TCPS_BOUND
3655                          * here.
3656                          *
3657                          * 2. Ideally, we should only check for state equals
3658                          * to TCPS_LISTEN. And the following check should be
3659                          * added.
3660                          *
3661                          * if (ltcp->tcp_state == TCPS_LISTEN ||
3662                          *      !reuseaddr || !ltcp->tcp_reuseaddr) {
3663                          *              ...
3664                          * }
3665                          *
3666                          * The semantics will be changed to this.  If the
3667                          * endpoint on the list is in state not equal to
3668                          * TCPS_LISTEN and both endpoints have SO_REUSEADDR
3669                          * set, let the bind succeed.
3670                          *
3671                          * Because of (1), we cannot do that for TLI
3672                          * endpoints.  But we can do that for socket endpoints.
3673                          * If in future, we can change this going back
3674                          * semantics, we can use the above check for TLI also.
3675                          */
3676                         not_socket = !(TCP_IS_SOCKET(ltcp) &&
3677                             TCP_IS_SOCKET(tcp));
3678                         exclbind = ltcp->tcp_exclbind || tcp->tcp_exclbind;
3679 
3680                         if (lconnp->conn_mac_exempt || connp->conn_mac_exempt ||
3681                             (exclbind && (not_socket ||
3682                             ltcp->tcp_state <= TCPS_ESTABLISHED))) {
3683                                 if (V6_OR_V4_INADDR_ANY(
3684                                     ltcp->tcp_bound_source_v6) ||
3685                                     V6_OR_V4_INADDR_ANY(*laddr) ||
3686                                     IN6_ARE_ADDR_EQUAL(laddr,
3687                                     &ltcp->tcp_bound_source_v6)) {
3688                                         break;
3689                                 }
3690                                 continue;
3691                         }
3692 
3693                         /*
3694                          * Check ipversion to allow IPv4 and IPv6 sockets to
3695                          * have disjoint port number spaces, if *_EXCLBIND
3696                          * is not set and only if the application binds to a
3697                          * specific port. We use the same autoassigned port
3698                          * number space for IPv4 and IPv6 sockets.
3699                          */
3700                         if (tcp->tcp_ipversion != ltcp->tcp_ipversion &&
3701                             bind_to_req_port_only)
3702                                 continue;
3703 
3704                         /*
3705                          * Ideally, we should make sure that the source
3706                          * address, remote address, and remote port in the
3707                          * four tuple for this tcp-connection is unique.
3708                          * However, trying to find out the local source
3709                          * address would require too much code duplication
3710                          * with IP, since IP needs needs to have that code
3711                          * to support userland TCP implementations.
3712                          */
3713                         if (quick_connect &&
3714                             (ltcp->tcp_state > TCPS_LISTEN) &&
3715                             ((tcp->tcp_fport != ltcp->tcp_fport) ||
3716                             !IN6_ARE_ADDR_EQUAL(&tcp->tcp_remote_v6,
3717                             &ltcp->tcp_remote_v6)))
3718                                 continue;
3719 
3720                         if (!reuseaddr) {
3721                                 /*
3722                                  * No socket option SO_REUSEADDR.
3723                                  * If existing port is bound to
3724                                  * a non-wildcard IP address
3725                                  * and the requesting stream is
3726                                  * bound to a distinct
3727                                  * different IP addresses
3728                                  * (non-wildcard, also), keep
3729                                  * going.
3730                                  */
3731                                 if (!V6_OR_V4_INADDR_ANY(*laddr) &&
3732                                     !V6_OR_V4_INADDR_ANY(
3733                                     ltcp->tcp_bound_source_v6) &&
3734                                     !IN6_ARE_ADDR_EQUAL(laddr,
3735                                     &ltcp->tcp_bound_source_v6))
3736                                         continue;
3737                                 if (ltcp->tcp_state >= TCPS_BOUND) {
3738                                         /*
3739                                          * This port is being used and
3740                                          * its state is >= TCPS_BOUND,
3741                                          * so we can't bind to it.
3742                                          */
3743                                         break;
3744                                 }
3745                         } else {
3746                                 /*
3747                                  * socket option SO_REUSEADDR is set on the
3748                                  * binding tcp_t.
3749                                  *
3750                                  * If two streams are bound to
3751                                  * same IP address or both addr
3752                                  * and bound source are wildcards
3753                                  * (INADDR_ANY), we want to stop
3754                                  * searching.
3755                                  * We have found a match of IP source
3756                                  * address and source port, which is
3757                                  * refused regardless of the
3758                                  * SO_REUSEADDR setting, so we break.
3759                                  */
3760                                 if (IN6_ARE_ADDR_EQUAL(laddr,
3761                                     &ltcp->tcp_bound_source_v6) &&
3762                                     (ltcp->tcp_state == TCPS_LISTEN ||
3763                                     ltcp->tcp_state == TCPS_BOUND))
3764                                         break;
3765                         }
3766                 }
3767                 if (ltcp != NULL) {
3768                         /* The port number is busy */
3769                         mutex_exit(&tbf->tf_lock);
3770                 } else {
3771                         /*
3772                          * This port is ours. Insert in fanout and mark as
3773                          * bound to prevent others from getting the port
3774                          * number.
3775                          */
3776                         tcp->tcp_state = TCPS_BOUND;
3777                         tcp->tcp_lport = htons(port);
3778                         *(uint16_t *)tcp->tcp_tcph->th_lport = tcp->tcp_lport;
3779 
3780                         ASSERT(&tcps->tcps_bind_fanout[TCP_BIND_HASH(
3781                             tcp->tcp_lport)] == tbf);
3782                         tcp_bind_hash_insert(tbf, tcp, 1);
3783 
3784                         mutex_exit(&tbf->tf_lock);
3785 
3786                         /*
3787                          * We don't want tcp_next_port_to_try to "inherit"
3788                          * a port number supplied by the user in a bind.
3789                          */
3790                         if (user_specified)
3791                                 return (port);
3792 
3793                         /*
3794                          * This is the only place where tcp_next_port_to_try
3795                          * is updated. After the update, it may or may not
3796                          * be in the valid range.
3797                          */
3798                         if (!tcp->tcp_anon_priv_bind)
3799                                 tcps->tcps_next_port_to_try = port + 1;
3800                         return (port);
3801                 }
3802 
3803                 if (tcp->tcp_anon_priv_bind) {
3804                         port = tcp_get_next_priv_port(tcp);
3805                 } else {
3806                         if (count == 0 && user_specified) {
3807                                 /*
3808                                  * We may have to return an anonymous port. So
3809                                  * get one to start with.
3810                                  */
3811                                 port =
3812                                     tcp_update_next_port(
3813                                     tcps->tcps_next_port_to_try,
3814                                     tcp, B_TRUE);
3815                                 user_specified = B_FALSE;
3816                         } else {
3817                                 port = tcp_update_next_port(port + 1, tcp,
3818                                     B_FALSE);
3819                         }
3820                 }
3821                 if (port == 0)
3822                         break;
3823 
3824                 /*
3825                  * Don't let this loop run forever in the case where
3826                  * all of the anonymous ports are in use.
3827                  */
3828         } while (++count < loopmax);
3829         return (0);
3830 }
3831 
3832 /*
3833  * tcp_clean_death / tcp_close_detached must not be called more than once
3834  * on a tcp. Thus every function that potentially calls tcp_clean_death
3835  * must check for the tcp state before calling tcp_clean_death.
3836  * Eg. tcp_input, tcp_rput_data, tcp_eager_kill, tcp_clean_death_wrapper,
3837  * tcp_timer_handler, all check for the tcp state.
3838  */
3839 /* ARGSUSED */
3840 void
3841 tcp_clean_death_wrapper(void *arg, mblk_t *mp, void *arg2)
3842 {
3843         tcp_t   *tcp = ((conn_t *)arg)->conn_tcp;
3844 
3845         freemsg(mp);
3846         if (tcp->tcp_state > TCPS_BOUND)
3847                 (void) tcp_clean_death(((conn_t *)arg)->conn_tcp,
3848                     ETIMEDOUT, 5);
3849 }
3850 
3851 /*
3852  * We are dying for some reason.  Try to do it gracefully.  (May be called
3853  * as writer.)
3854  *
3855  * Return -1 if the structure was not cleaned up (if the cleanup had to be
3856  * done by a service procedure).
3857  * TBD - Should the return value distinguish between the tcp_t being
3858  * freed and it being reinitialized?
3859  */
3860 static int
3861 tcp_clean_death(tcp_t *tcp, int err, uint8_t tag)
3862 {
3863         mblk_t  *mp;
3864         queue_t *q;
3865         tcp_stack_t     *tcps = tcp->tcp_tcps;
3866         sodirect_t      *sodp;
3867 
3868         TCP_CLD_STAT(tag);
3869 
3870 #if TCP_TAG_CLEAN_DEATH
3871         tcp->tcp_cleandeathtag = tag;
3872 #endif
3873 
3874         if (tcp->tcp_fused)
3875                 tcp_unfuse(tcp);
3876 
3877         if (tcp->tcp_linger_tid != 0 &&
3878             TCP_TIMER_CANCEL(tcp, tcp->tcp_linger_tid) >= 0) {
3879                 tcp_stop_lingering(tcp);
3880         }
3881 
3882         ASSERT(tcp != NULL);
3883         ASSERT((tcp->tcp_family == AF_INET &&
3884             tcp->tcp_ipversion == IPV4_VERSION) ||
3885             (tcp->tcp_family == AF_INET6 &&
3886             (tcp->tcp_ipversion == IPV4_VERSION ||
3887             tcp->tcp_ipversion == IPV6_VERSION)));
3888 
3889         if (TCP_IS_DETACHED(tcp)) {
3890                 if (tcp->tcp_hard_binding) {
3891                         /*
3892                          * Its an eager that we are dealing with. We close the
3893                          * eager but in case a conn_ind has already gone to the
3894                          * listener, let tcp_accept_finish() send a discon_ind
3895                          * to the listener and drop the last reference. If the
3896                          * listener doesn't even know about the eager i.e. the
3897                          * conn_ind hasn't gone up, blow away the eager and drop
3898                          * the last reference as well. If the conn_ind has gone
3899                          * up, state should be BOUND. tcp_accept_finish
3900                          * will figure out that the connection has received a
3901                          * RST and will send a DISCON_IND to the application.
3902                          */
3903                         tcp_closei_local(tcp);
3904                         if (!tcp->tcp_tconnind_started) {
3905                                 CONN_DEC_REF(tcp->tcp_connp);
3906                         } else {
3907                                 tcp->tcp_state = TCPS_BOUND;
3908                         }
3909                 } else {
3910                         tcp_close_detached(tcp);
3911                 }
3912                 return (0);
3913         }
3914 
3915         TCP_STAT(tcps, tcp_clean_death_nondetached);
3916 
3917         /*
3918          * If T_ORDREL_IND has not been sent yet (done when service routine
3919          * is run) postpone cleaning up the endpoint until service routine
3920          * has sent up the T_ORDREL_IND. Avoid clearing out an existing
3921          * client_errno since tcp_close uses the client_errno field.
3922          */
3923         if (tcp->tcp_fin_rcvd && !tcp->tcp_ordrel_done) {
3924                 if (err != 0)
3925                         tcp->tcp_client_errno = err;
3926 
3927                 tcp->tcp_deferred_clean_death = B_TRUE;
3928                 return (-1);
3929         }
3930 
3931         /* If sodirect, not anymore */
3932         SOD_PTR_ENTER(tcp, sodp);
3933         if (sodp != NULL) {
3934                 tcp->tcp_sodirect = NULL;
3935                 mutex_exit(sodp->sod_lock);
3936         }
3937 
3938         q = tcp->tcp_rq;
3939 
3940         /* Trash all inbound data */
3941         flushq(q, FLUSHALL);
3942 
3943         /*
3944          * If we are at least part way open and there is error
3945          * (err==0 implies no error)
3946          * notify our client by a T_DISCON_IND.
3947          */
3948         if ((tcp->tcp_state >= TCPS_SYN_SENT) && err) {
3949                 if (tcp->tcp_state >= TCPS_ESTABLISHED &&
3950                     !TCP_IS_SOCKET(tcp)) {
3951                         /*
3952                          * Send M_FLUSH according to TPI. Because sockets will
3953                          * (and must) ignore FLUSHR we do that only for TPI
3954                          * endpoints and sockets in STREAMS mode.
3955                          */
3956                         (void) putnextctl1(q, M_FLUSH, FLUSHR);
3957                 }
3958                 if (tcp->tcp_debug) {
3959                         (void) strlog(TCP_MOD_ID, 0, 1, SL_TRACE|SL_ERROR,
3960                             "tcp_clean_death: discon err %d", err);
3961                 }
3962                 mp = mi_tpi_discon_ind(NULL, err, 0);
3963                 if (mp != NULL) {
3964                         putnext(q, mp);
3965                 } else {
3966                         if (tcp->tcp_debug) {
3967                                 (void) strlog(TCP_MOD_ID, 0, 1,
3968                                     SL_ERROR|SL_TRACE,
3969                                     "tcp_clean_death, sending M_ERROR");
3970                         }
3971                         (void) putnextctl1(q, M_ERROR, EPROTO);
3972                 }
3973                 if (tcp->tcp_state <= TCPS_SYN_RCVD) {
3974                         /* SYN_SENT or SYN_RCVD */
3975                         BUMP_MIB(&tcps->tcps_mib, tcpAttemptFails);
3976                 } else if (tcp->tcp_state <= TCPS_CLOSE_WAIT) {
3977                         /* ESTABLISHED or CLOSE_WAIT */
3978                         BUMP_MIB(&tcps->tcps_mib, tcpEstabResets);
3979                 }
3980         }
3981 
3982         tcp_reinit(tcp);
3983         return (-1);
3984 }
3985 
3986 /*
3987  * In case tcp is in the "lingering state" and waits for the SO_LINGER timeout
3988  * to expire, stop the wait and finish the close.
3989  */
3990 static void
3991 tcp_stop_lingering(tcp_t *tcp)
3992 {
3993         clock_t delta = 0;
3994         tcp_stack_t     *tcps = tcp->tcp_tcps;
3995 
3996         tcp->tcp_linger_tid = 0;
3997         if (tcp->tcp_state > TCPS_LISTEN) {
3998                 tcp_acceptor_hash_remove(tcp);
3999                 mutex_enter(&tcp->tcp_non_sq_lock);
4000                 if (tcp->tcp_flow_stopped) {
4001                         tcp_clrqfull(tcp);
4002                 }
4003                 mutex_exit(&tcp->tcp_non_sq_lock);
4004 
4005                 if (tcp->tcp_timer_tid != 0) {
4006                         delta = TCP_TIMER_CANCEL(tcp, tcp->tcp_timer_tid);
4007                         tcp->tcp_timer_tid = 0;
4008                 }
4009                 /*
4010                  * Need to cancel those timers which will not be used when
4011                  * TCP is detached.  This has to be done before the tcp_wq
4012                  * is set to the global queue.
4013                  */
4014                 tcp_timers_stop(tcp);
4015 
4016 
4017                 tcp->tcp_detached = B_TRUE;
4018                 ASSERT(tcps->tcps_g_q != NULL);
4019                 tcp->tcp_rq = tcps->tcps_g_q;
4020                 tcp->tcp_wq = WR(tcps->tcps_g_q);
4021 
4022                 if (tcp->tcp_state == TCPS_TIME_WAIT) {
4023                         tcp_time_wait_append(tcp);
4024                         TCP_DBGSTAT(tcps, tcp_detach_time_wait);
4025                         goto finish;
4026                 }
4027 
4028                 /*
4029                  * If delta is zero the timer event wasn't executed and was
4030                  * successfully canceled. In this case we need to restart it
4031                  * with the minimal delta possible.
4032                  */
4033                 if (delta >= 0) {
4034                         tcp->tcp_timer_tid = TCP_TIMER(tcp, tcp_timer,
4035                             delta ? delta : 1);
4036                 }
4037         } else {
4038                 tcp_closei_local(tcp);
4039                 CONN_DEC_REF(tcp->tcp_connp);
4040         }
4041 finish:
4042         /* Signal closing thread that it can complete close */
4043         mutex_enter(&tcp->tcp_closelock);
4044         tcp->tcp_detached = B_TRUE;
4045         ASSERT(tcps->tcps_g_q != NULL);
4046         tcp->tcp_rq = tcps->tcps_g_q;
4047         tcp->tcp_wq = WR(tcps->tcps_g_q);
4048         tcp->tcp_closed = 1;
4049         cv_signal(&tcp->tcp_closecv);
4050         mutex_exit(&tcp->tcp_closelock);
4051 }
4052 
4053 /*
4054  * Handle lingering timeouts. This function is called when the SO_LINGER timeout
4055  * expires.
4056  */
4057 static void
4058 tcp_close_linger_timeout(void *arg)
4059 {
4060         conn_t  *connp = (conn_t *)arg;
4061         tcp_t   *tcp = connp->conn_tcp;
4062 
4063         tcp->tcp_client_errno = ETIMEDOUT;
4064         tcp_stop_lingering(tcp);
4065 }
4066 
4067 static int
4068 tcp_close(queue_t *q, int flags)
4069 {
4070         conn_t          *connp = Q_TO_CONN(q);
4071         tcp_t           *tcp = connp->conn_tcp;
4072         mblk_t          *mp = &tcp->tcp_closemp;
4073         boolean_t       conn_ioctl_cleanup_reqd = B_FALSE;
4074         mblk_t          *bp;
4075 
4076         ASSERT(WR(q)->q_next == NULL);
4077         ASSERT(connp->conn_ref >= 2);
4078 
4079         /*
4080          * We are being closed as /dev/tcp or /dev/tcp6.
4081          *
4082          * Mark the conn as closing. ill_pending_mp_add will not
4083          * add any mp to the pending mp list, after this conn has
4084          * started closing. Same for sq_pending_mp_add
4085          */
4086         mutex_enter(&connp->conn_lock);
4087         connp->conn_state_flags |= CONN_CLOSING;
4088         if (connp->conn_oper_pending_ill != NULL)
4089                 conn_ioctl_cleanup_reqd = B_TRUE;
4090         CONN_INC_REF_LOCKED(connp);
4091         mutex_exit(&connp->conn_lock);
4092         tcp->tcp_closeflags = (uint8_t)flags;
4093         ASSERT(connp->conn_ref >= 3);
4094 
4095         /*
4096          * tcp_closemp_used is used below without any protection of a lock
4097          * as we don't expect any one else to use it concurrently at this
4098          * point otherwise it would be a major defect.
4099          */
4100 
4101         if (mp->b_prev == NULL)
4102                 tcp->tcp_closemp_used = B_TRUE;
4103         else
4104                 cmn_err(CE_PANIC, "tcp_close: concurrent use of tcp_closemp: "
4105                     "connp %p tcp %p\n", (void *)connp, (void *)tcp);
4106 
4107         TCP_DEBUG_GETPCSTACK(tcp->tcmp_stk, 15);
4108 
4109         (*tcp_squeue_close_proc)(connp->conn_sqp, mp,
4110             tcp_close_output, connp, SQTAG_IP_TCP_CLOSE);
4111 
4112         mutex_enter(&tcp->tcp_closelock);
4113         while (!tcp->tcp_closed) {
4114                 if (!cv_wait_sig(&tcp->tcp_closecv, &tcp->tcp_closelock)) {
4115                         /*
4116                          * The cv_wait_sig() was interrupted. We now do the
4117                          * following:
4118                          *
4119                          * 1) If the endpoint was lingering, we allow this
4120                          * to be interrupted by cancelling the linger timeout
4121                          * and closing normally.
4122                          *
4123                          * 2) Revert to calling cv_wait()
4124                          *
4125                          * We revert to using cv_wait() to avoid an
4126                          * infinite loop which can occur if the calling
4127                          * thread is higher priority than the squeue worker
4128                          * thread and is bound to the same cpu.
4129                          */
4130                         if (tcp->tcp_linger && tcp->tcp_lingertime > 0) {
4131                                 mutex_exit(&tcp->tcp_closelock);
4132                                 /* Entering squeue, bump ref count. */
4133                                 CONN_INC_REF(connp);
4134                                 bp = allocb_wait(0, BPRI_HI, STR_NOSIG, NULL);
4135                                 squeue_enter(connp->conn_sqp, bp,
4136                                     tcp_linger_interrupted, connp,
4137                                     SQTAG_IP_TCP_CLOSE);
4138                                 mutex_enter(&tcp->tcp_closelock);
4139                         }
4140                         break;
4141                 }
4142         }
4143         while (!tcp->tcp_closed)
4144                 cv_wait(&tcp->tcp_closecv, &tcp->tcp_closelock);
4145         mutex_exit(&tcp->tcp_closelock);
4146 
4147         /*
4148          * In the case of listener streams that have eagers in the q or q0
4149          * we wait for the eagers to drop their reference to us. tcp_rq and
4150          * tcp_wq of the eagers point to our queues. By waiting for the
4151          * refcnt to drop to 1, we are sure that the eagers have cleaned
4152          * up their queue pointers and also dropped their references to us.
4153          */
4154         if (tcp->tcp_wait_for_eagers) {
4155                 mutex_enter(&connp->conn_lock);
4156                 while (connp->conn_ref != 1) {
4157                         cv_wait(&connp->conn_cv, &connp->conn_lock);
4158                 }
4159                 mutex_exit(&connp->conn_lock);
4160         }
4161         /*
4162          * ioctl cleanup. The mp is queued in the
4163          * ill_pending_mp or in the sq_pending_mp.
4164          */
4165         if (conn_ioctl_cleanup_reqd)
4166                 conn_ioctl_cleanup(connp);
4167 
4168         qprocsoff(q);
4169         inet_minor_free(connp->conn_minor_arena, connp->conn_dev);
4170 
4171         tcp->tcp_cpid = -1;
4172 
4173         /*
4174          * Drop IP's reference on the conn. This is the last reference
4175          * on the connp if the state was less than established. If the
4176          * connection has gone into timewait state, then we will have
4177          * one ref for the TCP and one more ref (total of two) for the
4178          * classifier connected hash list (a timewait connections stays
4179          * in connected hash till closed).
4180          *
4181          * We can't assert the references because there might be other
4182          * transient reference places because of some walkers or queued
4183          * packets in squeue for the timewait state.
4184          */
4185         CONN_DEC_REF(connp);
4186         q->q_ptr = WR(q)->q_ptr = NULL;
4187         return (0);
4188 }
4189 
4190 static int
4191 tcpclose_accept(queue_t *q)
4192 {
4193         vmem_t  *minor_arena;
4194         dev_t   conn_dev;
4195 
4196         ASSERT(WR(q)->q_qinfo == &tcp_acceptor_winit);
4197 
4198         /*
4199          * We had opened an acceptor STREAM for sockfs which is
4200          * now being closed due to some error.
4201          */
4202         qprocsoff(q);
4203 
4204         minor_arena = (vmem_t *)WR(q)->q_ptr;
4205         conn_dev = (dev_t)RD(q)->q_ptr;
4206         ASSERT(minor_arena != NULL);
4207         ASSERT(conn_dev != 0);
4208         inet_minor_free(minor_arena, conn_dev);
4209         q->q_ptr = WR(q)->q_ptr = NULL;
4210         return (0);
4211 }
4212 
4213 /*
4214  * Called by tcp_close() routine via squeue when lingering is
4215  * interrupted by a signal.
4216  */
4217 
4218 /* ARGSUSED */
4219 static void
4220 tcp_linger_interrupted(void *arg, mblk_t *mp, void *arg2)
4221 {
4222         conn_t  *connp = (conn_t *)arg;
4223         tcp_t   *tcp = connp->conn_tcp;
4224 
4225         freeb(mp);
4226         if (tcp->tcp_linger_tid != 0 &&
4227             TCP_TIMER_CANCEL(tcp, tcp->tcp_linger_tid) >= 0) {
4228                 tcp_stop_lingering(tcp);
4229                 tcp->tcp_client_errno = EINTR;
4230         }
4231 }
4232 
4233 /*
4234  * Called by streams close routine via squeues when our client blows off her
4235  * descriptor, we take this to mean: "close the stream state NOW, close the tcp
4236  * connection politely" When SO_LINGER is set (with a non-zero linger time and
4237  * it is not a nonblocking socket) then this routine sleeps until the FIN is
4238  * acked.
4239  *
4240  * NOTE: tcp_close potentially returns error when lingering.
4241  * However, the stream head currently does not pass these errors
4242  * to the application. 4.4BSD only returns EINTR and EWOULDBLOCK
4243  * errors to the application (from tsleep()) and not errors
4244  * like ECONNRESET caused by receiving a reset packet.
4245  */
4246 
4247 /* ARGSUSED */
4248 static void
4249 tcp_close_output(void *arg, mblk_t *mp, void *arg2)
4250 {
4251         char    *msg;
4252         conn_t  *connp = (conn_t *)arg;
4253         tcp_t   *tcp = connp->conn_tcp;
4254         clock_t delta = 0;
4255         tcp_stack_t     *tcps = tcp->tcp_tcps;
4256 
4257         ASSERT((connp->conn_fanout != NULL && connp->conn_ref >= 4) ||
4258             (connp->conn_fanout == NULL && connp->conn_ref >= 3));
4259 
4260         /* Cancel any pending timeout */
4261         if (tcp->tcp_ordrelid != 0) {
4262                 if (tcp->tcp_timeout) {
4263                         (void) TCP_TIMER_CANCEL(tcp, tcp->tcp_ordrelid);
4264                 }
4265                 tcp->tcp_ordrelid = 0;
4266                 tcp->tcp_timeout = B_FALSE;
4267         }
4268 
4269         mutex_enter(&tcp->tcp_eager_lock);
4270         if (tcp->tcp_conn_req_cnt_q0 != 0 || tcp->tcp_conn_req_cnt_q != 0) {
4271                 /* Cleanup for listener */
4272                 tcp_eager_cleanup(tcp, 0);
4273                 tcp->tcp_wait_for_eagers = 1;
4274         }
4275         mutex_exit(&tcp->tcp_eager_lock);
4276 
4277         connp->conn_mdt_ok = B_FALSE;
4278         tcp->tcp_mdt = B_FALSE;
4279 
4280         connp->conn_lso_ok = B_FALSE;
4281         tcp->tcp_lso = B_FALSE;
4282 
4283         msg = NULL;
4284         switch (tcp->tcp_state) {
4285         case TCPS_CLOSED:
4286         case TCPS_IDLE:
4287         case TCPS_BOUND:
4288         case TCPS_LISTEN:
4289                 break;
4290         case TCPS_SYN_SENT:
4291                 msg = "tcp_close, during connect";
4292                 break;
4293         case TCPS_SYN_RCVD:
4294                 /*
4295                  * Close during the connect 3-way handshake
4296                  * but here there may or may not be pending data
4297                  * already on queue. Process almost same as in
4298                  * the ESTABLISHED state.
4299                  */
4300                 /* FALLTHRU */
4301         default:
4302                 if (tcp->tcp_sodirect != NULL) {
4303                         /* Ok, no more sodirect */
4304                         tcp->tcp_sodirect = NULL;
4305                 }
4306 
4307                 if (tcp->tcp_fused)
4308                         tcp_unfuse(tcp);
4309 
4310                 /*
4311                  * If SO_LINGER has set a zero linger time, abort the
4312                  * connection with a reset.
4313                  */
4314                 if (tcp->tcp_linger && tcp->tcp_lingertime == 0) {
4315                         msg = "tcp_close, zero lingertime";
4316                         break;
4317                 }
4318 
4319                 ASSERT(tcp->tcp_hard_bound || tcp->tcp_hard_binding);
4320                 /*
4321                  * Abort connection if there is unread data queued.
4322                  */
4323                 if (tcp->tcp_rcv_list || tcp->tcp_reass_head) {
4324                         msg = "tcp_close, unread data";
4325                         break;
4326                 }
4327                 /*
4328                  * tcp_hard_bound is now cleared thus all packets go through
4329                  * tcp_lookup. This fact is used by tcp_detach below.
4330                  *
4331                  * We have done a qwait() above which could have possibly
4332                  * drained more messages in turn causing transition to a
4333                  * different state. Check whether we have to do the rest
4334                  * of the processing or not.
4335                  */
4336                 if (tcp->tcp_state <= TCPS_LISTEN)
4337                         break;
4338 
4339                 /*
4340                  * Transmit the FIN before detaching the tcp_t.
4341                  * After tcp_detach returns this queue/perimeter
4342                  * no longer owns the tcp_t thus others can modify it.
4343                  */
4344                 (void) tcp_xmit_end(tcp);
4345 
4346                 /*
4347                  * If lingering on close then wait until the fin is acked,
4348                  * the SO_LINGER time passes, or a reset is sent/received.
4349                  */
4350                 if (tcp->tcp_linger && tcp->tcp_lingertime > 0 &&
4351                     !(tcp->tcp_fin_acked) &&
4352                     tcp->tcp_state >= TCPS_ESTABLISHED) {
4353                         if (tcp->tcp_closeflags & (FNDELAY|FNONBLOCK)) {
4354                                 tcp->tcp_client_errno = EWOULDBLOCK;
4355                         } else if (tcp->tcp_client_errno == 0) {
4356 
4357                                 ASSERT(tcp->tcp_linger_tid == 0);
4358 
4359                                 tcp->tcp_linger_tid = TCP_TIMER(tcp,
4360                                     tcp_close_linger_timeout,
4361                                     tcp->tcp_lingertime * hz);
4362 
4363                                 /* tcp_close_linger_timeout will finish close */
4364                                 if (tcp->tcp_linger_tid == 0)
4365                                         tcp->tcp_client_errno = ENOSR;
4366                                 else
4367                                         return;
4368                         }
4369 
4370                         /*
4371                          * Check if we need to detach or just close
4372                          * the instance.
4373                          */
4374                         if (tcp->tcp_state <= TCPS_LISTEN)
4375                                 break;
4376                 }
4377 
4378                 /*
4379                  * Make sure that no other thread will access the tcp_rq of
4380                  * this instance (through lookups etc.) as tcp_rq will go
4381                  * away shortly.
4382                  */
4383                 tcp_acceptor_hash_remove(tcp);
4384 
4385                 mutex_enter(&tcp->tcp_non_sq_lock);
4386                 if (tcp->tcp_flow_stopped) {
4387                         tcp_clrqfull(tcp);
4388                 }
4389                 mutex_exit(&tcp->tcp_non_sq_lock);
4390 
4391                 if (tcp->tcp_timer_tid != 0) {
4392                         delta = TCP_TIMER_CANCEL(tcp, tcp->tcp_timer_tid);
4393                         tcp->tcp_timer_tid = 0;
4394                 }
4395                 /*
4396                  * Need to cancel those timers which will not be used when
4397                  * TCP is detached.  This has to be done before the tcp_wq
4398                  * is set to the global queue.
4399                  */
4400                 tcp_timers_stop(tcp);
4401 
4402                 tcp->tcp_detached = B_TRUE;
4403                 if (tcp->tcp_state == TCPS_TIME_WAIT) {
4404                         tcp_time_wait_append(tcp);
4405                         TCP_DBGSTAT(tcps, tcp_detach_time_wait);
4406                         ASSERT(connp->conn_ref >= 3);
4407                         goto finish;
4408                 }
4409 
4410                 /*
4411                  * If delta is zero the timer event wasn't executed and was
4412                  * successfully canceled. In this case we need to restart it
4413                  * with the minimal delta possible.
4414                  */
4415                 if (delta >= 0)
4416                         tcp->tcp_timer_tid = TCP_TIMER(tcp, tcp_timer,
4417                             delta ? delta : 1);
4418 
4419                 ASSERT(connp->conn_ref >= 3);
4420                 goto finish;
4421         }
4422 
4423         /* Detach did not complete. Still need to remove q from stream. */
4424         if (msg) {
4425                 if (tcp->tcp_state == TCPS_ESTABLISHED ||
4426                     tcp->tcp_state == TCPS_CLOSE_WAIT)
4427                         BUMP_MIB(&tcps->tcps_mib, tcpEstabResets);
4428                 if (tcp->tcp_state == TCPS_SYN_SENT ||
4429                     tcp->tcp_state == TCPS_SYN_RCVD)
4430                         BUMP_MIB(&tcps->tcps_mib, tcpAttemptFails);
4431                 tcp_xmit_ctl(msg, tcp,  tcp->tcp_snxt, 0, TH_RST);
4432         }
4433 
4434         tcp_closei_local(tcp);
4435         CONN_DEC_REF(connp);
4436         ASSERT(connp->conn_ref >= 2);
4437 
4438 finish:
4439         /*
4440          * Although packets are always processed on the correct
4441          * tcp's perimeter and access is serialized via squeue's,
4442          * IP still needs a queue when sending packets in time_wait
4443          * state so use WR(tcps_g_q) till ip_output() can be
4444          * changed to deal with just connp. For read side, we
4445          * could have set tcp_rq to NULL but there are some cases
4446          * in tcp_rput_data() from early days of this code which
4447          * do a putnext without checking if tcp is closed. Those
4448          * need to be identified before both tcp_rq and tcp_wq
4449          * can be set to NULL and tcps_g_q can disappear forever.
4450          */
4451         mutex_enter(&tcp->tcp_closelock);
4452         /*
4453          * Don't change the queues in the case of a listener that has
4454          * eagers in its q or q0. It could surprise the eagers.
4455          * Instead wait for the eagers outside the squeue.
4456          */
4457         if (!tcp->tcp_wait_for_eagers) {
4458                 tcp->tcp_detached = B_TRUE;
4459                 /*
4460                  * When default queue is closing we set tcps_g_q to NULL
4461                  * after the close is done.
4462                  */
4463                 ASSERT(tcps->tcps_g_q != NULL);
4464                 tcp->tcp_rq = tcps->tcps_g_q;
4465                 tcp->tcp_wq = WR(tcps->tcps_g_q);
4466         }
4467 
4468         /* Signal tcp_close() to finish closing. */
4469         tcp->tcp_closed = 1;
4470         cv_signal(&tcp->tcp_closecv);
4471         mutex_exit(&tcp->tcp_closelock);
4472 }
4473 
4474 
4475 /*
4476  * Clean up the b_next and b_prev fields of every mblk pointed at by *mpp.
4477  * Some stream heads get upset if they see these later on as anything but NULL.
4478  */
4479 static void
4480 tcp_close_mpp(mblk_t **mpp)
4481 {
4482         mblk_t  *mp;
4483 
4484         if ((mp = *mpp) != NULL) {
4485                 do {
4486                         mp->b_next = NULL;
4487                         mp->b_prev = NULL;
4488                 } while ((mp = mp->b_cont) != NULL);
4489 
4490                 mp = *mpp;
4491                 *mpp = NULL;
4492                 freemsg(mp);
4493         }
4494 }
4495 
4496 /* Do detached close. */
4497 static void
4498 tcp_close_detached(tcp_t *tcp)
4499 {
4500         if (tcp->tcp_fused)
4501                 tcp_unfuse(tcp);
4502 
4503         /*
4504          * Clustering code serializes TCP disconnect callbacks and
4505          * cluster tcp list walks by blocking a TCP disconnect callback
4506          * if a cluster tcp list walk is in progress. This ensures
4507          * accurate accounting of TCPs in the cluster code even though
4508          * the TCP list walk itself is not atomic.
4509          */
4510         tcp_closei_local(tcp);
4511         CONN_DEC_REF(tcp->tcp_connp);
4512 }
4513 
4514 /*
4515  * Stop all TCP timers, and free the timer mblks if requested.
4516  */
4517 void
4518 tcp_timers_stop(tcp_t *tcp)
4519 {
4520         if (tcp->tcp_timer_tid != 0) {
4521                 (void) TCP_TIMER_CANCEL(tcp, tcp->tcp_timer_tid);
4522                 tcp->tcp_timer_tid = 0;
4523         }
4524         if (tcp->tcp_ka_tid != 0) {
4525                 (void) TCP_TIMER_CANCEL(tcp, tcp->tcp_ka_tid);
4526                 tcp->tcp_ka_tid = 0;
4527         }
4528         if (tcp->tcp_ack_tid != 0) {
4529                 (void) TCP_TIMER_CANCEL(tcp, tcp->tcp_ack_tid);
4530                 tcp->tcp_ack_tid = 0;
4531         }
4532         if (tcp->tcp_push_tid != 0) {
4533                 (void) TCP_TIMER_CANCEL(tcp, tcp->tcp_push_tid);
4534                 tcp->tcp_push_tid = 0;
4535         }
4536 }
4537 
4538 /*
4539  * The tcp_t is going away. Remove it from all lists and set it
4540  * to TCPS_CLOSED. The freeing up of memory is deferred until
4541  * tcp_inactive. This is needed since a thread in tcp_rput might have
4542  * done a CONN_INC_REF on this structure before it was removed from the
4543  * hashes.
4544  */
4545 static void
4546 tcp_closei_local(tcp_t *tcp)
4547 {
4548         ire_t   *ire;
4549         conn_t  *connp = tcp->tcp_connp;
4550         tcp_stack_t     *tcps = tcp->tcp_tcps;
4551 
4552         if (!TCP_IS_SOCKET(tcp))
4553                 tcp_acceptor_hash_remove(tcp);
4554 
4555         UPDATE_MIB(&tcps->tcps_mib, tcpHCInSegs, tcp->tcp_ibsegs);
4556         tcp->tcp_ibsegs = 0;
4557         UPDATE_MIB(&tcps->tcps_mib, tcpHCOutSegs, tcp->tcp_obsegs);
4558         tcp->tcp_obsegs = 0;
4559 
4560         /*
4561          * If we are an eager connection hanging off a listener that
4562          * hasn't formally accepted the connection yet, get off his
4563          * list and blow off any data that we have accumulated.
4564          */
4565         if (tcp->tcp_listener != NULL) {
4566                 tcp_t   *listener = tcp->tcp_listener;
4567                 mutex_enter(&listener->tcp_eager_lock);
4568                 /*
4569                  * tcp_tconnind_started == B_TRUE means that the
4570                  * conn_ind has already gone to listener. At
4571                  * this point, eager will be closed but we
4572                  * leave it in listeners eager list so that
4573                  * if listener decides to close without doing
4574                  * accept, we can clean this up. In tcp_wput_accept
4575                  * we take care of the case of accept on closed
4576                  * eager.
4577                  */
4578                 if (!tcp->tcp_tconnind_started) {
4579                         tcp_eager_unlink(tcp);
4580                         mutex_exit(&listener->tcp_eager_lock);
4581                         /*
4582                          * We don't want to have any pointers to the
4583                          * listener queue, after we have released our
4584                          * reference on the listener
4585                          */
4586                         ASSERT(tcps->tcps_g_q != NULL);
4587                         tcp->tcp_rq = tcps->tcps_g_q;
4588                         tcp->tcp_wq = WR(tcps->tcps_g_q);
4589                         CONN_DEC_REF(listener->tcp_connp);
4590                 } else {
4591                         mutex_exit(&listener->tcp_eager_lock);
4592                 }
4593         }
4594 
4595         /* Stop all the timers */
4596         tcp_timers_stop(tcp);
4597 
4598         if (tcp->tcp_state == TCPS_LISTEN) {
4599                 if (tcp->tcp_ip_addr_cache) {
4600                         kmem_free((void *)tcp->tcp_ip_addr_cache,
4601                             IP_ADDR_CACHE_SIZE * sizeof (ipaddr_t));
4602                         tcp->tcp_ip_addr_cache = NULL;
4603                 }
4604         }
4605         mutex_enter(&tcp->tcp_non_sq_lock);
4606         if (tcp->tcp_flow_stopped)
4607                 tcp_clrqfull(tcp);
4608         mutex_exit(&tcp->tcp_non_sq_lock);
4609 
4610         tcp_bind_hash_remove(tcp);
4611         /*
4612          * If the tcp_time_wait_collector (which runs outside the squeue)
4613          * is trying to remove this tcp from the time wait list, we will
4614          * block in tcp_time_wait_remove while trying to acquire the
4615          * tcp_time_wait_lock. The logic in tcp_time_wait_collector also
4616          * requires the ipcl_hash_remove to be ordered after the
4617          * tcp_time_wait_remove for the refcnt checks to work correctly.
4618          */
4619         if (tcp->tcp_state == TCPS_TIME_WAIT)
4620                 (void) tcp_time_wait_remove(tcp, NULL);
4621         CL_INET_DISCONNECT(tcp);
4622         ipcl_hash_remove(connp);
4623 
4624         /*
4625          * Delete the cached ire in conn_ire_cache and also mark
4626          * the conn as CONDEMNED
4627          */
4628         mutex_enter(&connp->conn_lock);
4629         connp->conn_state_flags |= CONN_CONDEMNED;
4630         ire = connp->conn_ire_cache;
4631         connp->conn_ire_cache = NULL;
4632         mutex_exit(&connp->conn_lock);
4633         if (ire != NULL)
4634                 IRE_REFRELE_NOTR(ire);
4635 
4636         /* Need to cleanup any pending ioctls */
4637         ASSERT(tcp->tcp_time_wait_next == NULL);
4638         ASSERT(tcp->tcp_time_wait_prev == NULL);
4639         ASSERT(tcp->tcp_time_wait_expire == 0);
4640         tcp->tcp_state = TCPS_CLOSED;
4641 
4642         /* Release any SSL context */
4643         if (tcp->tcp_kssl_ent != NULL) {
4644                 kssl_release_ent(tcp->tcp_kssl_ent, NULL, KSSL_NO_PROXY);
4645                 tcp->tcp_kssl_ent = NULL;
4646         }
4647         if (tcp->tcp_kssl_ctx != NULL) {
4648                 kssl_release_ctx(tcp->tcp_kssl_ctx);
4649                 tcp->tcp_kssl_ctx = NULL;
4650         }
4651         tcp->tcp_kssl_pending = B_FALSE;
4652 
4653         tcp_ipsec_cleanup(tcp);
4654 }
4655 
4656 /*
4657  * tcp is dying (called from ipcl_conn_destroy and error cases).
4658  * Free the tcp_t in either case.
4659  */
4660 void
4661 tcp_free(tcp_t *tcp)
4662 {
4663         mblk_t  *mp;
4664         ip6_pkt_t       *ipp;
4665 
4666         ASSERT(tcp != NULL);
4667         ASSERT(tcp->tcp_ptpahn == NULL && tcp->tcp_acceptor_hash == NULL);
4668 
4669         tcp->tcp_rq = NULL;
4670         tcp->tcp_wq = NULL;
4671 
4672         tcp_close_mpp(&tcp->tcp_xmit_head);
4673         tcp_close_mpp(&tcp->tcp_reass_head);
4674         if (tcp->tcp_rcv_list != NULL) {
4675                 /* Free b_next chain */
4676                 tcp_close_mpp(&tcp->tcp_rcv_list);
4677         }
4678         if ((mp = tcp->tcp_urp_mp) != NULL) {
4679                 freemsg(mp);
4680         }
4681         if ((mp = tcp->tcp_urp_mark_mp) != NULL) {
4682                 freemsg(mp);
4683         }
4684 
4685         if (tcp->tcp_fused_sigurg_mp != NULL) {
4686                 freeb(tcp->tcp_fused_sigurg_mp);
4687                 tcp->tcp_fused_sigurg_mp = NULL;
4688         }
4689 
4690         if (tcp->tcp_sack_info != NULL) {
4691                 if (tcp->tcp_notsack_list != NULL) {
4692                         TCP_NOTSACK_REMOVE_ALL(tcp->tcp_notsack_list);
4693                 }
4694                 bzero(tcp->tcp_sack_info, sizeof (tcp_sack_info_t));
4695         }
4696 
4697         if (tcp->tcp_hopopts != NULL) {
4698                 mi_free(tcp->tcp_hopopts);
4699                 tcp->tcp_hopopts = NULL;
4700                 tcp->tcp_hopoptslen = 0;
4701         }
4702         ASSERT(tcp->tcp_hopoptslen == 0);
4703         if (tcp->tcp_dstopts != NULL) {
4704                 mi_free(tcp->tcp_dstopts);
4705                 tcp->tcp_dstopts = NULL;
4706                 tcp->tcp_dstoptslen = 0;
4707         }
4708         ASSERT(tcp->tcp_dstoptslen == 0);
4709         if (tcp->tcp_rtdstopts != NULL) {
4710                 mi_free(tcp->tcp_rtdstopts);
4711                 tcp->tcp_rtdstopts = NULL;
4712                 tcp->tcp_rtdstoptslen = 0;
4713         }
4714         ASSERT(tcp->tcp_rtdstoptslen == 0);
4715         if (tcp->tcp_rthdr != NULL) {
4716                 mi_free(tcp->tcp_rthdr);
4717                 tcp->tcp_rthdr = NULL;
4718                 tcp->tcp_rthdrlen = 0;
4719         }
4720         ASSERT(tcp->tcp_rthdrlen == 0);
4721 
4722         ipp = &tcp->tcp_sticky_ipp;
4723         if (ipp->ipp_fields & (IPPF_HOPOPTS | IPPF_RTDSTOPTS | IPPF_DSTOPTS |
4724             IPPF_RTHDR))
4725                 ip6_pkt_free(ipp);
4726 
4727         /*
4728          * Free memory associated with the tcp/ip header template.
4729          */
4730 
4731         if (tcp->tcp_iphc != NULL)
4732                 bzero(tcp->tcp_iphc, tcp->tcp_iphc_len);
4733 
4734         /*
4735          * Following is really a blowing away a union.
4736          * It happens to have exactly two members of identical size
4737          * the following code is enough.
4738          */
4739         tcp_close_mpp(&tcp->tcp_conn.tcp_eager_conn_ind);
4740 
4741         if (tcp->tcp_tracebuf != NULL) {
4742                 kmem_free(tcp->tcp_tracebuf, sizeof (tcptrch_t));
4743                 tcp->tcp_tracebuf = NULL;
4744         }
4745 }
4746 
4747 
4748 /*
4749  * Put a connection confirmation message upstream built from the
4750  * address information within 'iph' and 'tcph'.  Report our success or failure.
4751  */
4752 static boolean_t
4753 tcp_conn_con(tcp_t *tcp, uchar_t *iphdr, tcph_t *tcph, mblk_t *idmp,
4754     mblk_t **defermp)
4755 {
4756         sin_t   sin;
4757         sin6_t  sin6;
4758         mblk_t  *mp;
4759         char    *optp = NULL;
4760         int     optlen = 0;
4761         cred_t  *cr;
4762 
4763         if (defermp != NULL)
4764                 *defermp = NULL;
4765 
4766         if (tcp->tcp_conn.tcp_opts_conn_req != NULL) {
4767                 /*
4768                  * Return in T_CONN_CON results of option negotiation through
4769                  * the T_CONN_REQ. Note: If there is an real end-to-end option
4770                  * negotiation, then what is received from remote end needs
4771                  * to be taken into account but there is no such thing (yet?)
4772                  * in our TCP/IP.
4773                  * Note: We do not use mi_offset_param() here as
4774                  * tcp_opts_conn_req contents do not directly come from
4775                  * an application and are either generated in kernel or
4776                  * from user input that was already verified.
4777                  */
4778                 mp = tcp->tcp_conn.tcp_opts_conn_req;
4779                 optp = (char *)(mp->b_rptr +
4780                     ((struct T_conn_req *)mp->b_rptr)->OPT_offset);
4781                 optlen = (int)
4782                     ((struct T_conn_req *)mp->b_rptr)->OPT_length;
4783         }
4784 
4785         if (IPH_HDR_VERSION(iphdr) == IPV4_VERSION) {
4786                 ipha_t *ipha = (ipha_t *)iphdr;
4787 
4788                 /* packet is IPv4 */
4789                 if (tcp->tcp_family == AF_INET) {
4790                         sin = sin_null;
4791                         sin.sin_addr.s_addr = ipha->ipha_src;
4792                         sin.sin_port = *(uint16_t *)tcph->th_lport;
4793                         sin.sin_family = AF_INET;
4794                         mp = mi_tpi_conn_con(NULL, (char *)&sin,
4795                             (int)sizeof (sin_t), optp, optlen);
4796                 } else {
4797                         sin6 = sin6_null;
4798                         IN6_IPADDR_TO_V4MAPPED(ipha->ipha_src, &sin6.sin6_addr);
4799                         sin6.sin6_port = *(uint16_t *)tcph->th_lport;
4800                         sin6.sin6_family = AF_INET6;
4801                         mp = mi_tpi_conn_con(NULL, (char *)&sin6,
4802                             (int)sizeof (sin6_t), optp, optlen);
4803 
4804                 }
4805         } else {
4806                 ip6_t   *ip6h = (ip6_t *)iphdr;
4807 
4808                 ASSERT(IPH_HDR_VERSION(iphdr) == IPV6_VERSION);
4809                 ASSERT(tcp->tcp_family == AF_INET6);
4810                 sin6 = sin6_null;
4811                 sin6.sin6_addr = ip6h->ip6_src;
4812                 sin6.sin6_port = *(uint16_t *)tcph->th_lport;
4813                 sin6.sin6_family = AF_INET6;
4814                 sin6.sin6_flowinfo = ip6h->ip6_vcf & ~IPV6_VERS_AND_FLOW_MASK;
4815                 mp = mi_tpi_conn_con(NULL, (char *)&sin6,
4816                     (int)sizeof (sin6_t), optp, optlen);
4817         }
4818 
4819         if (!mp)
4820                 return (B_FALSE);
4821 
4822         if ((cr = DB_CRED(idmp)) != NULL) {
4823                 mblk_setcred(mp, cr);
4824                 DB_CPID(mp) = DB_CPID(idmp);
4825         }
4826 
4827         if (defermp == NULL)
4828                 putnext(tcp->tcp_rq, mp);
4829         else
4830                 *defermp = mp;
4831 
4832         if (tcp->tcp_conn.tcp_opts_conn_req != NULL)
4833                 tcp_close_mpp(&tcp->tcp_conn.tcp_opts_conn_req);
4834         return (B_TRUE);
4835 }
4836 
4837 /*
4838  * Defense for the SYN attack -
4839  * 1. When q0 is full, drop from the tail (tcp_eager_prev_drop_q0) the oldest
4840  *    one from the list of droppable eagers. This list is a subset of q0.
4841  *    see comments before the definition of MAKE_DROPPABLE().
4842  * 2. Don't drop a SYN request before its first timeout. This gives every
4843  *    request at least til the first timeout to complete its 3-way handshake.
4844  * 3. Maintain tcp_syn_rcvd_timeout as an accurate count of how many
4845  *    requests currently on the queue that has timed out. This will be used
4846  *    as an indicator of whether an attack is under way, so that appropriate
4847  *    actions can be taken. (It's incremented in tcp_timer() and decremented
4848  *    either when eager goes into ESTABLISHED, or gets freed up.)
4849  * 4. The current threshold is - # of timeout > q0len/4 => SYN alert on
4850  *    # of timeout drops back to <= q0len/32 => SYN alert off
4851  */
4852 static boolean_t
4853 tcp_drop_q0(tcp_t *tcp)
4854 {
4855         tcp_t   *eager;
4856         mblk_t  *mp;
4857         tcp_stack_t     *tcps = tcp->tcp_tcps;
4858 
4859         ASSERT(MUTEX_HELD(&tcp->tcp_eager_lock));
4860         ASSERT(tcp->tcp_eager_next_q0 != tcp->tcp_eager_prev_q0);
4861 
4862         /* Pick oldest eager from the list of droppable eagers */
4863         eager = tcp->tcp_eager_prev_drop_q0;
4864 
4865         /* If list is empty. return B_FALSE */
4866         if (eager == tcp) {
4867                 return (B_FALSE);
4868         }
4869 
4870         /* If allocated, the mp will be freed in tcp_clean_death_wrapper() */
4871         if ((mp = allocb(0, BPRI_HI)) == NULL)
4872                 return (B_FALSE);
4873 
4874         /*
4875          * Take this eager out from the list of droppable eagers since we are
4876          * going to drop it.
4877          */
4878         MAKE_UNDROPPABLE(eager);
4879 
4880         if (tcp->tcp_debug) {
4881                 (void) strlog(TCP_MOD_ID, 0, 3, SL_TRACE,
4882                     "tcp_drop_q0: listen half-open queue (max=%d) overflow"
4883                     " (%d pending) on %s, drop one", tcps->tcps_conn_req_max_q0,
4884                     tcp->tcp_conn_req_cnt_q0,
4885                     tcp_display(tcp, NULL, DISP_PORT_ONLY));
4886         }
4887 
4888         BUMP_MIB(&tcps->tcps_mib, tcpHalfOpenDrop);
4889 
4890         /* Put a reference on the conn as we are enqueueing it in the sqeue */
4891         CONN_INC_REF(eager->tcp_connp);
4892 
4893         /* Mark the IRE created for this SYN request temporary */
4894         tcp_ip_ire_mark_advice(eager);
4895         squeue_fill(eager->tcp_connp->conn_sqp, mp,
4896             tcp_clean_death_wrapper, eager->tcp_connp, SQTAG_TCP_DROP_Q0);
4897 
4898         return (B_TRUE);
4899 }
4900 
4901 int
4902 tcp_conn_create_v6(conn_t *lconnp, conn_t *connp, mblk_t *mp,
4903     tcph_t *tcph, uint_t ipvers, mblk_t *idmp)
4904 {
4905         tcp_t           *ltcp = lconnp->conn_tcp;
4906         tcp_t           *tcp = connp->conn_tcp;
4907         mblk_t          *tpi_mp;
4908         ipha_t          *ipha;
4909         ip6_t           *ip6h;
4910         sin6_t          sin6;
4911         in6_addr_t      v6dst;
4912         int             err;
4913         int             ifindex = 0;
4914         cred_t          *cr;
4915         tcp_stack_t     *tcps = tcp->tcp_tcps;
4916 
4917         if (ipvers == IPV4_VERSION) {
4918                 ipha = (ipha_t *)mp->b_rptr;
4919 
4920                 connp->conn_send = ip_output;
4921                 connp->conn_recv = tcp_input;
4922 
4923                 IN6_IPADDR_TO_V4MAPPED(ipha->ipha_dst, &connp->conn_srcv6);
4924                 IN6_IPADDR_TO_V4MAPPED(ipha->ipha_src, &connp->conn_remv6);
4925 
4926                 sin6 = sin6_null;
4927                 IN6_IPADDR_TO_V4MAPPED(ipha->ipha_src, &sin6.sin6_addr);
4928                 IN6_IPADDR_TO_V4MAPPED(ipha->ipha_dst, &v6dst);
4929                 sin6.sin6_port = *(uint16_t *)tcph->th_lport;
4930                 sin6.sin6_family = AF_INET6;
4931                 sin6.__sin6_src_id = ip_srcid_find_addr(&v6dst,
4932                     lconnp->conn_zoneid, tcps->tcps_netstack);
4933                 if (tcp->tcp_recvdstaddr) {
4934                         sin6_t  sin6d;
4935 
4936                         sin6d = sin6_null;
4937                         IN6_IPADDR_TO_V4MAPPED(ipha->ipha_dst,
4938                             &sin6d.sin6_addr);
4939                         sin6d.sin6_port = *(uint16_t *)tcph->th_fport;
4940                         sin6d.sin6_family = AF_INET;
4941                         tpi_mp = mi_tpi_extconn_ind(NULL,
4942                             (char *)&sin6d, sizeof (sin6_t),
4943                             (char *)&tcp,
4944                             (t_scalar_t)sizeof (intptr_t),
4945                             (char *)&sin6d, sizeof (sin6_t),
4946                             (t_scalar_t)ltcp->tcp_conn_req_seqnum);
4947                 } else {
4948                         tpi_mp = mi_tpi_conn_ind(NULL,
4949                             (char *)&sin6, sizeof (sin6_t),
4950                             (char *)&tcp, (t_scalar_t)sizeof (intptr_t),
4951                             (t_scalar_t)ltcp->tcp_conn_req_seqnum);
4952                 }
4953         } else {
4954                 ip6h = (ip6_t *)mp->b_rptr;
4955 
4956                 connp->conn_send = ip_output_v6;
4957                 connp->conn_recv = tcp_input;
4958 
4959                 connp->conn_srcv6 = ip6h->ip6_dst;
4960                 connp->conn_remv6 = ip6h->ip6_src;
4961 
4962                 /* db_cksumstuff is set at ip_fanout_tcp_v6 */
4963                 ifindex = (int)DB_CKSUMSTUFF(mp);
4964                 DB_CKSUMSTUFF(mp) = 0;
4965 
4966                 sin6 = sin6_null;
4967                 sin6.sin6_addr = ip6h->ip6_src;
4968                 sin6.sin6_port = *(uint16_t *)tcph->th_lport;
4969                 sin6.sin6_family = AF_INET6;
4970                 sin6.sin6_flowinfo = ip6h->ip6_vcf & ~IPV6_VERS_AND_FLOW_MASK;
4971                 sin6.__sin6_src_id = ip_srcid_find_addr(&ip6h->ip6_dst,
4972                     lconnp->conn_zoneid, tcps->tcps_netstack);
4973 
4974                 if (IN6_IS_ADDR_LINKSCOPE(&ip6h->ip6_src)) {
4975                         /* Pass up the scope_id of remote addr */
4976                         sin6.sin6_scope_id = ifindex;
4977                 } else {
4978                         sin6.sin6_scope_id = 0;
4979                 }
4980                 if (tcp->tcp_recvdstaddr) {
4981                         sin6_t  sin6d;
4982 
4983                         sin6d = sin6_null;
4984                         sin6.sin6_addr = ip6h->ip6_dst;
4985                         sin6d.sin6_port = *(uint16_t *)tcph->th_fport;
4986                         sin6d.sin6_family = AF_INET;
4987                         tpi_mp = mi_tpi_extconn_ind(NULL,
4988                             (char *)&sin6d, sizeof (sin6_t),
4989                             (char *)&tcp, (t_scalar_t)sizeof (intptr_t),
4990                             (char *)&sin6d, sizeof (sin6_t),
4991                             (t_scalar_t)ltcp->tcp_conn_req_seqnum);
4992                 } else {
4993                         tpi_mp = mi_tpi_conn_ind(NULL,
4994                             (char *)&sin6, sizeof (sin6_t),
4995                             (char *)&tcp, (t_scalar_t)sizeof (intptr_t),
4996                             (t_scalar_t)ltcp->tcp_conn_req_seqnum);
4997                 }
4998         }
4999 
5000         if (tpi_mp == NULL)
5001                 return (ENOMEM);
5002 
5003         connp->conn_fport = *(uint16_t *)tcph->th_lport;
5004         connp->conn_lport = *(uint16_t *)tcph->th_fport;
5005         connp->conn_flags |= (IPCL_TCP6|IPCL_EAGER);
5006         connp->conn_fully_bound = B_FALSE;
5007 
5008         if (tcps->tcps_trace)
5009                 tcp->tcp_tracebuf = kmem_zalloc(sizeof (tcptrch_t), KM_NOSLEEP);
5010 
5011         /* Inherit information from the "parent" */
5012         tcp->tcp_ipversion = ltcp->tcp_ipversion;
5013         tcp->tcp_family = ltcp->tcp_family;
5014         tcp->tcp_wq = ltcp->tcp_wq;
5015         tcp->tcp_rq = ltcp->tcp_rq;
5016         tcp->tcp_mss = tcps->tcps_mss_def_ipv6;
5017         tcp->tcp_detached = B_TRUE;
5018         if ((err = tcp_init_values(tcp)) != 0) {
5019                 freemsg(tpi_mp);
5020                 return (err);
5021         }
5022 
5023         if (ipvers == IPV4_VERSION) {
5024                 if ((err = tcp_header_init_ipv4(tcp)) != 0) {
5025                         freemsg(tpi_mp);
5026                         return (err);
5027                 }
5028                 ASSERT(tcp->tcp_ipha != NULL);
5029         } else {
5030                 /* ifindex must be already set */
5031                 ASSERT(ifindex != 0);
5032 
5033                 if (ltcp->tcp_bound_if != 0) {
5034                         /*
5035                          * Set newtcp's bound_if equal to
5036                          * listener's value. If ifindex is
5037                          * not the same as ltcp->tcp_bound_if,
5038                          * it must be a packet for the ipmp group
5039                          * of interfaces
5040                          */
5041                         tcp->tcp_bound_if = ltcp->tcp_bound_if;
5042                 } else if (IN6_IS_ADDR_LINKSCOPE(&ip6h->ip6_src)) {
5043                         tcp->tcp_bound_if = ifindex;
5044                 }
5045 
5046                 tcp->tcp_ipv6_recvancillary = ltcp->tcp_ipv6_recvancillary;
5047                 tcp->tcp_recvifindex = 0;
5048                 tcp->tcp_recvhops = 0xffffffffU;
5049                 ASSERT(tcp->tcp_ip6h != NULL);
5050         }
5051 
5052         tcp->tcp_lport = ltcp->tcp_lport;
5053 
5054         if (ltcp->tcp_ipversion == tcp->tcp_ipversion) {
5055                 if (tcp->tcp_iphc_len != ltcp->tcp_iphc_len) {
5056                         /*
5057                          * Listener had options of some sort; eager inherits.
5058                          * Free up the eager template and allocate one
5059                          * of the right size.
5060                          */
5061                         if (tcp->tcp_hdr_grown) {
5062                                 kmem_free(tcp->tcp_iphc, tcp->tcp_iphc_len);
5063                         } else {
5064                                 bzero(tcp->tcp_iphc, tcp->tcp_iphc_len);
5065                                 kmem_cache_free(tcp_iphc_cache, tcp->tcp_iphc);
5066                         }
5067                         tcp->tcp_iphc = kmem_zalloc(ltcp->tcp_iphc_len,
5068                             KM_NOSLEEP);
5069                         if (tcp->tcp_iphc == NULL) {
5070                                 tcp->tcp_iphc_len = 0;
5071                                 freemsg(tpi_mp);
5072                                 return (ENOMEM);
5073                         }
5074                         tcp->tcp_iphc_len = ltcp->tcp_iphc_len;
5075                         tcp->tcp_hdr_grown = B_TRUE;
5076                 }
5077                 tcp->tcp_hdr_len = ltcp->tcp_hdr_len;
5078                 tcp->tcp_ip_hdr_len = ltcp->tcp_ip_hdr_len;
5079                 tcp->tcp_tcp_hdr_len = ltcp->tcp_tcp_hdr_len;
5080                 tcp->tcp_ip6_hops = ltcp->tcp_ip6_hops;
5081                 tcp->tcp_ip6_vcf = ltcp->tcp_ip6_vcf;
5082 
5083                 /*
5084                  * Copy the IP+TCP header template from listener to eager
5085                  */
5086                 bcopy(ltcp->tcp_iphc, tcp->tcp_iphc, ltcp->tcp_hdr_len);
5087                 if (tcp->tcp_ipversion == IPV6_VERSION) {
5088                         if (((ip6i_t *)(tcp->tcp_iphc))->ip6i_nxt ==
5089                             IPPROTO_RAW) {
5090                                 tcp->tcp_ip6h =
5091                                     (ip6_t *)(tcp->tcp_iphc +
5092                                     sizeof (ip6i_t));
5093                         } else {
5094                                 tcp->tcp_ip6h =
5095                                     (ip6_t *)(tcp->tcp_iphc);
5096                         }
5097                         tcp->tcp_ipha = NULL;
5098                 } else {
5099                         tcp->tcp_ipha = (ipha_t *)tcp->tcp_iphc;
5100                         tcp->tcp_ip6h = NULL;
5101                 }
5102                 tcp->tcp_tcph = (tcph_t *)(tcp->tcp_iphc +
5103                     tcp->tcp_ip_hdr_len);
5104         } else {
5105                 /*
5106                  * only valid case when ipversion of listener and
5107                  * eager differ is when listener is IPv6 and
5108                  * eager is IPv4.
5109                  * Eager header template has been initialized to the
5110                  * maximum v4 header sizes, which includes space for
5111                  * TCP and IP options.
5112                  */
5113                 ASSERT((ltcp->tcp_ipversion == IPV6_VERSION) &&
5114                     (tcp->tcp_ipversion == IPV4_VERSION));
5115                 ASSERT(tcp->tcp_iphc_len >=
5116                     TCP_MAX_COMBINED_HEADER_LENGTH);
5117                 tcp->tcp_tcp_hdr_len = ltcp->tcp_tcp_hdr_len;
5118                 /* copy IP header fields individually */
5119                 tcp->tcp_ipha->ipha_ttl =
5120                     ltcp->tcp_ip6h->ip6_hops;
5121                 bcopy(ltcp->tcp_tcph->th_lport,
5122                     tcp->tcp_tcph->th_lport, sizeof (ushort_t));
5123         }
5124 
5125         bcopy(tcph->th_lport, tcp->tcp_tcph->th_fport, sizeof (in_port_t));
5126         bcopy(tcp->tcp_tcph->th_fport, &tcp->tcp_fport,
5127             sizeof (in_port_t));
5128 
5129         if (ltcp->tcp_lport == 0) {
5130                 tcp->tcp_lport = *(in_port_t *)tcph->th_fport;
5131                 bcopy(tcph->th_fport, tcp->tcp_tcph->th_lport,
5132                     sizeof (in_port_t));
5133         }
5134 
5135         if (tcp->tcp_ipversion == IPV4_VERSION) {
5136                 ASSERT(ipha != NULL);
5137                 tcp->tcp_ipha->ipha_dst = ipha->ipha_src;
5138                 tcp->tcp_ipha->ipha_src = ipha->ipha_dst;
5139 
5140                 /* Source routing option copyover (reverse it) */
5141                 if (tcps->tcps_rev_src_routes)
5142                         tcp_opt_reverse(tcp, ipha);
5143         } else {
5144                 ASSERT(ip6h != NULL);
5145                 tcp->tcp_ip6h->ip6_dst = ip6h->ip6_src;
5146                 tcp->tcp_ip6h->ip6_src = ip6h->ip6_dst;
5147         }
5148 
5149         ASSERT(tcp->tcp_conn.tcp_eager_conn_ind == NULL);
5150         ASSERT(!tcp->tcp_tconnind_started);
5151         /*
5152          * If the SYN contains a credential, it's a loopback packet; attach
5153          * the credential to the TPI message.
5154          */
5155         if ((cr = DB_CRED(idmp)) != NULL) {
5156                 mblk_setcred(tpi_mp, cr);
5157                 DB_CPID(tpi_mp) = DB_CPID(idmp);
5158         }
5159         tcp->tcp_conn.tcp_eager_conn_ind = tpi_mp;
5160 
5161         /* Inherit the listener's SSL protection state */
5162 
5163         if ((tcp->tcp_kssl_ent = ltcp->tcp_kssl_ent) != NULL) {
5164                 kssl_hold_ent(tcp->tcp_kssl_ent);
5165                 tcp->tcp_kssl_pending = B_TRUE;
5166         }
5167 
5168         return (0);
5169 }
5170 
5171 
5172 int
5173 tcp_conn_create_v4(conn_t *lconnp, conn_t *connp, ipha_t *ipha,
5174     tcph_t *tcph, mblk_t *idmp)
5175 {
5176         tcp_t           *ltcp = lconnp->conn_tcp;
5177         tcp_t           *tcp = connp->conn_tcp;
5178         sin_t           sin;
5179         mblk_t          *tpi_mp = NULL;
5180         int             err;
5181         cred_t          *cr;
5182         tcp_stack_t     *tcps = tcp->tcp_tcps;
5183 
5184         sin = sin_null;
5185         sin.sin_addr.s_addr = ipha->ipha_src;
5186         sin.sin_port = *(uint16_t *)tcph->th_lport;
5187         sin.sin_family = AF_INET;
5188         if (ltcp->tcp_recvdstaddr) {
5189                 sin_t   sind;
5190 
5191                 sind = sin_null;
5192                 sind.sin_addr.s_addr = ipha->ipha_dst;
5193                 sind.sin_port = *(uint16_t *)tcph->th_fport;
5194                 sind.sin_family = AF_INET;
5195                 tpi_mp = mi_tpi_extconn_ind(NULL,
5196                     (char *)&sind, sizeof (sin_t), (char *)&tcp,
5197                     (t_scalar_t)sizeof (intptr_t), (char *)&sind,
5198                     sizeof (sin_t), (t_scalar_t)ltcp->tcp_conn_req_seqnum);
5199         } else {
5200                 tpi_mp = mi_tpi_conn_ind(NULL,
5201                     (char *)&sin, sizeof (sin_t),
5202                     (char *)&tcp, (t_scalar_t)sizeof (intptr_t),
5203                     (t_scalar_t)ltcp->tcp_conn_req_seqnum);
5204         }
5205 
5206         if (tpi_mp == NULL) {
5207                 return (ENOMEM);
5208         }
5209 
5210         connp->conn_flags |= (IPCL_TCP4|IPCL_EAGER);
5211         connp->conn_send = ip_output;
5212         connp->conn_recv = tcp_input;
5213         connp->conn_fully_bound = B_FALSE;
5214 
5215         IN6_IPADDR_TO_V4MAPPED(ipha->ipha_dst, &connp->conn_srcv6);
5216         IN6_IPADDR_TO_V4MAPPED(ipha->ipha_src, &connp->conn_remv6);
5217         connp->conn_fport = *(uint16_t *)tcph->th_lport;
5218         connp->conn_lport = *(uint16_t *)tcph->th_fport;
5219 
5220         if (tcps->tcps_trace) {
5221                 tcp->tcp_tracebuf = kmem_zalloc(sizeof (tcptrch_t), KM_NOSLEEP);
5222         }
5223 
5224         /* Inherit information from the "parent" */
5225         tcp->tcp_ipversion = ltcp->tcp_ipversion;
5226         tcp->tcp_family = ltcp->tcp_family;
5227         tcp->tcp_wq = ltcp->tcp_wq;
5228         tcp->tcp_rq = ltcp->tcp_rq;
5229         tcp->tcp_mss = tcps->tcps_mss_def_ipv4;
5230         tcp->tcp_detached = B_TRUE;
5231         if ((err = tcp_init_values(tcp)) != 0) {
5232                 freemsg(tpi_mp);
5233                 return (err);
5234         }
5235 
5236         /*
5237          * Let's make sure that eager tcp template has enough space to
5238          * copy IPv4 listener's tcp template. Since the conn_t structure is
5239          * preserved and tcp_iphc_len is also preserved, an eager conn_t may
5240          * have a tcp_template of total len TCP_MAX_COMBINED_HEADER_LENGTH or
5241          * more (in case of re-allocation of conn_t with tcp-IPv6 template with
5242          * extension headers or with ip6i_t struct). Note that bcopy() below
5243          * copies listener tcp's hdr_len which cannot be greater than TCP_MAX_
5244          * COMBINED_HEADER_LENGTH as this listener must be a IPv4 listener.
5245          */
5246         ASSERT(tcp->tcp_iphc_len >= TCP_MAX_COMBINED_HEADER_LENGTH);
5247         ASSERT(ltcp->tcp_hdr_len <= TCP_MAX_COMBINED_HEADER_LENGTH);
5248 
5249         tcp->tcp_hdr_len = ltcp->tcp_hdr_len;
5250         tcp->tcp_ip_hdr_len = ltcp->tcp_ip_hdr_len;
5251         tcp->tcp_tcp_hdr_len = ltcp->tcp_tcp_hdr_len;
5252         tcp->tcp_ttl = ltcp->tcp_ttl;
5253         tcp->tcp_tos = ltcp->tcp_tos;
5254 
5255         /* Copy the IP+TCP header template from listener to eager */
5256         bcopy(ltcp->tcp_iphc, tcp->tcp_iphc, ltcp->tcp_hdr_len);
5257         tcp->tcp_ipha = (ipha_t *)tcp->tcp_iphc;
5258         tcp->tcp_ip6h = NULL;
5259         tcp->tcp_tcph = (tcph_t *)(tcp->tcp_iphc +
5260             tcp->tcp_ip_hdr_len);
5261 
5262         /* Initialize the IP addresses and Ports */
5263         tcp->tcp_ipha->ipha_dst = ipha->ipha_src;
5264         tcp->tcp_ipha->ipha_src = ipha->ipha_dst;
5265         bcopy(tcph->th_lport, tcp->tcp_tcph->th_fport, sizeof (in_port_t));
5266         bcopy(tcph->th_fport, tcp->tcp_tcph->th_lport, sizeof (in_port_t));
5267 
5268         /* Source routing option copyover (reverse it) */
5269         if (tcps->tcps_rev_src_routes)
5270                 tcp_opt_reverse(tcp, ipha);
5271 
5272         ASSERT(tcp->tcp_conn.tcp_eager_conn_ind == NULL);
5273         ASSERT(!tcp->tcp_tconnind_started);
5274 
5275         /*
5276          * If the SYN contains a credential, it's a loopback packet; attach
5277          * the credential to the TPI message.
5278          */
5279         if ((cr = DB_CRED(idmp)) != NULL) {
5280                 mblk_setcred(tpi_mp, cr);
5281                 DB_CPID(tpi_mp) = DB_CPID(idmp);
5282         }
5283         tcp->tcp_conn.tcp_eager_conn_ind = tpi_mp;
5284 
5285         /* Inherit the listener's SSL protection state */
5286         if ((tcp->tcp_kssl_ent = ltcp->tcp_kssl_ent) != NULL) {
5287                 kssl_hold_ent(tcp->tcp_kssl_ent);
5288                 tcp->tcp_kssl_pending = B_TRUE;
5289         }
5290 
5291         return (0);
5292 }
5293 
5294 /*
5295  * sets up conn for ipsec.
5296  * if the first mblk is M_CTL it is consumed and mpp is updated.
5297  * in case of error mpp is freed.
5298  */
5299 conn_t *
5300 tcp_get_ipsec_conn(tcp_t *tcp, squeue_t *sqp, mblk_t **mpp)
5301 {
5302         conn_t          *connp = tcp->tcp_connp;
5303         conn_t          *econnp;
5304         squeue_t        *new_sqp;
5305         mblk_t          *first_mp = *mpp;
5306         mblk_t          *mp = *mpp;
5307         boolean_t       mctl_present = B_FALSE;
5308         uint_t          ipvers;
5309 
5310         econnp = tcp_get_conn(sqp, tcp->tcp_tcps);
5311         if (econnp == NULL) {
5312                 freemsg(first_mp);
5313                 return (NULL);
5314         }
5315         if (DB_TYPE(mp) == M_CTL) {
5316                 if (mp->b_cont == NULL ||
5317                     mp->b_cont->b_datap->db_type != M_DATA) {
5318                         freemsg(first_mp);
5319                         return (NULL);
5320                 }
5321                 mp = mp->b_cont;
5322                 if ((mp->b_datap->db_struioflag & STRUIO_EAGER) == 0) {
5323                         freemsg(first_mp);
5324                         return (NULL);
5325                 }
5326 
5327                 mp->b_datap->db_struioflag &= ~STRUIO_EAGER;
5328                 first_mp->b_datap->db_struioflag &= ~STRUIO_POLICY;
5329                 mctl_present = B_TRUE;
5330         } else {
5331                 ASSERT(mp->b_datap->db_struioflag & STRUIO_POLICY);
5332                 mp->b_datap->db_struioflag &= ~STRUIO_POLICY;
5333         }
5334 
5335         new_sqp = (squeue_t *)DB_CKSUMSTART(mp);
5336         DB_CKSUMSTART(mp) = 0;
5337 
5338         ASSERT(OK_32PTR(mp->b_rptr));
5339         ipvers = IPH_HDR_VERSION(mp->b_rptr);
5340         if (ipvers == IPV4_VERSION) {
5341                 uint16_t        *up;
5342                 uint32_t        ports;
5343                 ipha_t          *ipha;
5344 
5345                 ipha = (ipha_t *)mp->b_rptr;
5346                 up = (uint16_t *)((uchar_t *)ipha +
5347                     IPH_HDR_LENGTH(ipha) + TCP_PORTS_OFFSET);
5348                 ports = *(uint32_t *)up;
5349                 IPCL_TCP_EAGER_INIT(econnp, IPPROTO_TCP,
5350                     ipha->ipha_dst, ipha->ipha_src, ports);
5351         } else {
5352                 uint16_t        *up;
5353                 uint32_t        ports;
5354                 uint16_t        ip_hdr_len;
5355                 uint8_t         *nexthdrp;
5356                 ip6_t           *ip6h;
5357                 tcph_t          *tcph;
5358 
5359                 ip6h = (ip6_t *)mp->b_rptr;
5360                 if (ip6h->ip6_nxt == IPPROTO_TCP) {
5361                         ip_hdr_len = IPV6_HDR_LEN;
5362                 } else if (!ip_hdr_length_nexthdr_v6(mp, ip6h, &ip_hdr_len,
5363                     &nexthdrp) || *nexthdrp != IPPROTO_TCP) {
5364                         CONN_DEC_REF(econnp);
5365                         freemsg(first_mp);
5366                         return (NULL);
5367                 }
5368                 tcph = (tcph_t *)&mp->b_rptr[ip_hdr_len];
5369                 up = (uint16_t *)tcph->th_lport;
5370                 ports = *(uint32_t *)up;
5371                 IPCL_TCP_EAGER_INIT_V6(econnp, IPPROTO_TCP,
5372                     ip6h->ip6_dst, ip6h->ip6_src, ports);
5373         }
5374 
5375         /*
5376          * The caller already ensured that there is a sqp present.
5377          */
5378         econnp->conn_sqp = new_sqp;
5379 
5380         if (connp->conn_policy != NULL) {
5381                 ipsec_in_t *ii;
5382                 ii = (ipsec_in_t *)(first_mp->b_rptr);
5383                 ASSERT(ii->ipsec_in_policy == NULL);
5384                 IPPH_REFHOLD(connp->conn_policy);
5385                 ii->ipsec_in_policy = connp->conn_policy;
5386 
5387                 first_mp->b_datap->db_type = IPSEC_POLICY_SET;
5388                 if (!ip_bind_ipsec_policy_set(econnp, first_mp)) {
5389                         CONN_DEC_REF(econnp);
5390                         freemsg(first_mp);
5391                         return (NULL);
5392                 }
5393         }
5394 
5395         if (ipsec_conn_cache_policy(econnp, ipvers == IPV4_VERSION) != 0) {
5396                 CONN_DEC_REF(econnp);
5397                 freemsg(first_mp);
5398                 return (NULL);
5399         }
5400 
5401         /*
5402          * If we know we have some policy, pass the "IPSEC"
5403          * options size TCP uses this adjust the MSS.
5404          */
5405         econnp->conn_tcp->tcp_ipsec_overhead = conn_ipsec_length(econnp);
5406         if (mctl_present) {
5407                 freeb(first_mp);
5408                 *mpp = mp;
5409         }
5410 
5411         return (econnp);
5412 }
5413 
5414 /*
5415  * tcp_get_conn/tcp_free_conn
5416  *
5417  * tcp_get_conn is used to get a clean tcp connection structure.
5418  * It tries to reuse the connections put on the freelist by the
5419  * time_wait_collector failing which it goes to kmem_cache. This
5420  * way has two benefits compared to just allocating from and
5421  * freeing to kmem_cache.
5422  * 1) The time_wait_collector can free (which includes the cleanup)
5423  * outside the squeue. So when the interrupt comes, we have a clean
5424  * connection sitting in the freelist. Obviously, this buys us
5425  * performance.
5426  *
5427  * 2) Defence against DOS attack. Allocating a tcp/conn in tcp_conn_request
5428  * has multiple disadvantages - tying up the squeue during alloc, and the
5429  * fact that IPSec policy initialization has to happen here which
5430  * requires us sending a M_CTL and checking for it i.e. real ugliness.
5431  * But allocating the conn/tcp in IP land is also not the best since
5432  * we can't check the 'q' and 'q0' which are protected by squeue and
5433  * blindly allocate memory which might have to be freed here if we are
5434  * not allowed to accept the connection. By using the freelist and
5435  * putting the conn/tcp back in freelist, we don't pay a penalty for
5436  * allocating memory without checking 'q/q0' and freeing it if we can't
5437  * accept the connection.
5438  *
5439  * Care should be taken to put the conn back in the same squeue's freelist
5440  * from which it was allocated. Best results are obtained if conn is
5441  * allocated from listener's squeue and freed to the same. Time wait
5442  * collector will free up the freelist is the connection ends up sitting
5443  * there for too long.
5444  */
5445 void *
5446 tcp_get_conn(void *arg, tcp_stack_t *tcps)
5447 {
5448         tcp_t                   *tcp = NULL;
5449         conn_t                  *connp = NULL;
5450         squeue_t                *sqp = (squeue_t *)arg;
5451         tcp_squeue_priv_t       *tcp_time_wait;
5452         netstack_t              *ns;
5453 
5454         tcp_time_wait =
5455             *((tcp_squeue_priv_t **)squeue_getprivate(sqp, SQPRIVATE_TCP));
5456 
5457         mutex_enter(&tcp_time_wait->tcp_time_wait_lock);
5458         tcp = tcp_time_wait->tcp_free_list;
5459         ASSERT((tcp != NULL) ^ (tcp_time_wait->tcp_free_list_cnt == 0));
5460         if (tcp != NULL) {
5461                 tcp_time_wait->tcp_free_list = tcp->tcp_time_wait_next;
5462                 tcp_time_wait->tcp_free_list_cnt--;
5463                 mutex_exit(&tcp_time_wait->tcp_time_wait_lock);
5464                 tcp->tcp_time_wait_next = NULL;
5465                 connp = tcp->tcp_connp;
5466                 connp->conn_flags |= IPCL_REUSED;
5467 
5468                 ASSERT(tcp->tcp_tcps == NULL);
5469                 ASSERT(connp->conn_netstack == NULL);
5470                 ns = tcps->tcps_netstack;
5471                 netstack_hold(ns);
5472                 connp->conn_netstack = ns;
5473                 tcp->tcp_tcps = tcps;
5474                 TCPS_REFHOLD(tcps);
5475                 ipcl_globalhash_insert(connp);
5476                 return ((void *)connp);
5477         }
5478         mutex_exit(&tcp_time_wait->tcp_time_wait_lock);
5479         if ((connp = ipcl_conn_create(IPCL_TCPCONN, KM_NOSLEEP,
5480             tcps->tcps_netstack)) == NULL)
5481                 return (NULL);
5482         tcp = connp->conn_tcp;
5483         tcp->tcp_tcps = tcps;
5484         TCPS_REFHOLD(tcps);
5485         return ((void *)connp);
5486 }
5487 
5488 /*
5489  * Update the cached label for the given tcp_t.  This should be called once per
5490  * connection, and before any packets are sent or tcp_process_options is
5491  * invoked.  Returns B_FALSE if the correct label could not be constructed.
5492  */
5493 static boolean_t
5494 tcp_update_label(tcp_t *tcp, const cred_t *cr)
5495 {
5496         conn_t *connp = tcp->tcp_connp;
5497 
5498         if (tcp->tcp_ipversion == IPV4_VERSION) {
5499                 uchar_t optbuf[IP_MAX_OPT_LENGTH];
5500                 int added;
5501 
5502                 if (tsol_compute_label(cr, tcp->tcp_remote, optbuf,
5503                     connp->conn_mac_exempt,
5504                     tcp->tcp_tcps->tcps_netstack->netstack_ip) != 0)
5505                         return (B_FALSE);
5506 
5507                 added = tsol_remove_secopt(tcp->tcp_ipha, tcp->tcp_hdr_len);
5508                 if (added == -1)
5509                         return (B_FALSE);
5510                 tcp->tcp_hdr_len += added;
5511                 tcp->tcp_tcph = (tcph_t *)((uchar_t *)tcp->tcp_tcph + added);
5512                 tcp->tcp_ip_hdr_len += added;
5513                 if ((tcp->tcp_label_len = optbuf[IPOPT_OLEN]) != 0) {
5514                         tcp->tcp_label_len = (tcp->tcp_label_len + 3) & ~3;
5515                         added = tsol_prepend_option(optbuf, tcp->tcp_ipha,
5516                             tcp->tcp_hdr_len);
5517                         if (added == -1)
5518                                 return (B_FALSE);
5519                         tcp->tcp_hdr_len += added;
5520                         tcp->tcp_tcph = (tcph_t *)
5521                             ((uchar_t *)tcp->tcp_tcph + added);
5522                         tcp->tcp_ip_hdr_len += added;
5523                 }
5524         } else {
5525                 uchar_t optbuf[TSOL_MAX_IPV6_OPTION];
5526 
5527                 if (tsol_compute_label_v6(cr, &tcp->tcp_remote_v6, optbuf,
5528                     connp->conn_mac_exempt,
5529                     tcp->tcp_tcps->tcps_netstack->netstack_ip) != 0)
5530                         return (B_FALSE);
5531                 if (tsol_update_sticky(&tcp->tcp_sticky_ipp,
5532                     &tcp->tcp_label_len, optbuf) != 0)
5533                         return (B_FALSE);
5534                 if (tcp_build_hdrs(tcp->tcp_rq, tcp) != 0)
5535                         return (B_FALSE);
5536         }
5537 
5538         connp->conn_ulp_labeled = 1;
5539 
5540         return (B_TRUE);
5541 }
5542 
5543 /* BEGIN CSTYLED */
5544 /*
5545  *
5546  * The sockfs ACCEPT path:
5547  * =======================
5548  *
5549  * The eager is now established in its own perimeter as soon as SYN is
5550  * received in tcp_conn_request(). When sockfs receives conn_ind, it
5551  * completes the accept processing on the acceptor STREAM. The sending
5552  * of conn_ind part is common for both sockfs listener and a TLI/XTI
5553  * listener but a TLI/XTI listener completes the accept processing
5554  * on the listener perimeter.
5555  *
5556  * Common control flow for 3 way handshake:
5557  * ----------------------------------------
5558  *
5559  * incoming SYN (listener perimeter)    -> tcp_rput_data()
5560  *                                      -> tcp_conn_request()
5561  *
5562  * incoming SYN-ACK-ACK (eager perim)   -> tcp_rput_data()
5563  * send T_CONN_IND (listener perim)     -> tcp_send_conn_ind()
5564  *
5565  * Sockfs ACCEPT Path:
5566  * -------------------
5567  *
5568  * open acceptor stream (tcp_open allocates tcp_wput_accept()
5569  * as STREAM entry point)
5570  *
5571  * soaccept() sends T_CONN_RES on the acceptor STREAM to tcp_wput_accept()
5572  *
5573  * tcp_wput_accept() extracts the eager and makes the q->q_ptr <-> eager
5574  * association (we are not behind eager's squeue but sockfs is protecting us
5575  * and no one knows about this stream yet. The STREAMS entry point q->q_info
5576  * is changed to point at tcp_wput().
5577  *
5578  * tcp_wput_accept() sends any deferred eagers via tcp_send_pending() to
5579  * listener (done on listener's perimeter).
5580  *
5581  * tcp_wput_accept() calls tcp_accept_finish() on eagers perimeter to finish
5582  * accept.
5583  *
5584  * TLI/XTI client ACCEPT path:
5585  * ---------------------------
5586  *
5587  * soaccept() sends T_CONN_RES on the listener STREAM.
5588  *
5589  * tcp_accept() -> tcp_accept_swap() complete the processing and send
5590  * the bind_mp to eager perimeter to finish accept (tcp_rput_other()).
5591  *
5592  * Locks:
5593  * ======
5594  *
5595  * listener->tcp_eager_lock protects the listeners->tcp_eager_next_q0 and
5596  * and listeners->tcp_eager_next_q.
5597  *
5598  * Referencing:
5599  * ============
5600  *
5601  * 1) We start out in tcp_conn_request by eager placing a ref on
5602  * listener and listener adding eager to listeners->tcp_eager_next_q0.
5603  *
5604  * 2) When a SYN-ACK-ACK arrives, we send the conn_ind to listener. Before
5605  * doing so we place a ref on the eager. This ref is finally dropped at the
5606  * end of tcp_accept_finish() while unwinding from the squeue, i.e. the
5607  * reference is dropped by the squeue framework.
5608  *
5609  * 3) The ref on listener placed in 1 above is dropped in tcp_accept_finish
5610  *
5611  * The reference must be released by the same entity that added the reference
5612  * In the above scheme, the eager is the entity that adds and releases the
5613  * references. Note that tcp_accept_finish executes in the squeue of the eager
5614  * (albeit after it is attached to the acceptor stream). Though 1. executes
5615  * in the listener's squeue, the eager is nascent at this point and the
5616  * reference can be considered to have been added on behalf of the eager.
5617  *
5618  * Eager getting a Reset or listener closing:
5619  * ==========================================
5620  *
5621  * Once the listener and eager are linked, the listener never does the unlink.
5622  * If the listener needs to close, tcp_eager_cleanup() is called which queues
5623  * a message on all eager perimeter. The eager then does the unlink, clears
5624  * any pointers to the listener's queue and drops the reference to the
5625  * listener. The listener waits in tcp_close outside the squeue until its
5626  * refcount has dropped to 1. This ensures that the listener has waited for
5627  * all eagers to clear their association with the listener.
5628  *
5629  * Similarly, if eager decides to go away, it can unlink itself and close.
5630  * When the T_CONN_RES comes down, we check if eager has closed. Note that
5631  * the reference to eager is still valid because of the extra ref we put
5632  * in tcp_send_conn_ind.
5633  *
5634  * Listener can always locate the eager under the protection
5635  * of the listener->tcp_eager_lock, and then do a refhold
5636  * on the eager during the accept processing.
5637  *
5638  * The acceptor stream accesses the eager in the accept processing
5639  * based on the ref placed on eager before sending T_conn_ind.
5640  * The only entity that can negate this refhold is a listener close
5641  * which is mutually exclusive with an active acceptor stream.
5642  *
5643  * Eager's reference on the listener
5644  * ===================================
5645  *
5646  * If the accept happens (even on a closed eager) the eager drops its
5647  * reference on the listener at the start of tcp_accept_finish. If the
5648  * eager is killed due to an incoming RST before the T_conn_ind is sent up,
5649  * the reference is dropped in tcp_closei_local. If the listener closes,
5650  * the reference is dropped in tcp_eager_kill. In all cases the reference
5651  * is dropped while executing in the eager's context (squeue).
5652  */
5653 /* END CSTYLED */
5654 
5655 /* Process the SYN packet, mp, directed at the listener 'tcp' */
5656 
5657 /*
5658  * THIS FUNCTION IS DIRECTLY CALLED BY IP VIA SQUEUE FOR SYN.
5659  * tcp_rput_data will not see any SYN packets.
5660  */
5661 /* ARGSUSED */
5662 void
5663 tcp_conn_request(void *arg, mblk_t *mp, void *arg2)
5664 {
5665         tcph_t          *tcph;
5666         uint32_t        seg_seq;
5667         tcp_t           *eager;
5668         uint_t          ipvers;
5669         ipha_t          *ipha;
5670         ip6_t           *ip6h;
5671         int             err;
5672         conn_t          *econnp = NULL;
5673         squeue_t        *new_sqp;
5674         mblk_t          *mp1;
5675         uint_t          ip_hdr_len;
5676         conn_t          *connp = (conn_t *)arg;
5677         tcp_t           *tcp = connp->conn_tcp;
5678         cred_t          *credp;
5679         tcp_stack_t     *tcps = tcp->tcp_tcps;
5680         ip_stack_t      *ipst;
5681 
5682         if (tcp->tcp_state != TCPS_LISTEN)
5683                 goto error2;
5684 
5685         ASSERT((tcp->tcp_connp->conn_flags & IPCL_BOUND) != 0);
5686 
5687         mutex_enter(&tcp->tcp_eager_lock);
5688         if (tcp->tcp_conn_req_cnt_q >= tcp->tcp_conn_req_max) {
5689                 mutex_exit(&tcp->tcp_eager_lock);
5690                 TCP_STAT(tcps, tcp_listendrop);
5691                 BUMP_MIB(&tcps->tcps_mib, tcpListenDrop);
5692                 if (tcp->tcp_debug) {
5693                         (void) strlog(TCP_MOD_ID, 0, 1, SL_TRACE|SL_ERROR,
5694                             "tcp_conn_request: listen backlog (max=%d) "
5695                             "overflow (%d pending) on %s",
5696                             tcp->tcp_conn_req_max, tcp->tcp_conn_req_cnt_q,
5697                             tcp_display(tcp, NULL, DISP_PORT_ONLY));
5698                 }
5699                 goto error2;
5700         }
5701 
5702         if (tcp->tcp_conn_req_cnt_q0 >=
5703             tcp->tcp_conn_req_max + tcps->tcps_conn_req_max_q0) {
5704                 /*
5705                  * Q0 is full. Drop a pending half-open req from the queue
5706                  * to make room for the new SYN req. Also mark the time we
5707                  * drop a SYN.
5708                  *
5709                  * A more aggressive defense against SYN attack will
5710                  * be to set the "tcp_syn_defense" flag now.
5711                  */
5712                 TCP_STAT(tcps, tcp_listendropq0);
5713                 tcp->tcp_last_rcv_lbolt = lbolt64;
5714                 if (!tcp_drop_q0(tcp)) {
5715                         mutex_exit(&tcp->tcp_eager_lock);
5716                         BUMP_MIB(&tcps->tcps_mib, tcpListenDropQ0);
5717                         if (tcp->tcp_debug) {
5718                                 (void) strlog(TCP_MOD_ID, 0, 3, SL_TRACE,
5719                                     "tcp_conn_request: listen half-open queue "
5720                                     "(max=%d) full (%d pending) on %s",
5721                                     tcps->tcps_conn_req_max_q0,
5722                                     tcp->tcp_conn_req_cnt_q0,
5723                                     tcp_display(tcp, NULL,
5724                                     DISP_PORT_ONLY));
5725                         }
5726                         goto error2;
5727                 }
5728         }
5729         mutex_exit(&tcp->tcp_eager_lock);
5730 
5731         /*
5732          * IP adds STRUIO_EAGER and ensures that the received packet is
5733          * M_DATA even if conn_ipv6_recvpktinfo is enabled or for ip6
5734          * link local address.  If IPSec is enabled, db_struioflag has
5735          * STRUIO_POLICY set (mutually exclusive from STRUIO_EAGER);
5736          * otherwise an error case if neither of them is set.
5737          */
5738         if ((mp->b_datap->db_struioflag & STRUIO_EAGER) != 0) {
5739                 new_sqp = (squeue_t *)DB_CKSUMSTART(mp);
5740                 DB_CKSUMSTART(mp) = 0;
5741                 mp->b_datap->db_struioflag &= ~STRUIO_EAGER;
5742                 econnp = (conn_t *)tcp_get_conn(arg2, tcps);
5743                 if (econnp == NULL)
5744                         goto error2;
5745                 ASSERT(econnp->conn_netstack == connp->conn_netstack);
5746                 econnp->conn_sqp = new_sqp;
5747         } else if ((mp->b_datap->db_struioflag & STRUIO_POLICY) != 0) {
5748                 /*
5749                  * mp is updated in tcp_get_ipsec_conn().
5750                  */
5751                 econnp = tcp_get_ipsec_conn(tcp, arg2, &mp);
5752                 if (econnp == NULL) {
5753                         /*
5754                          * mp freed by tcp_get_ipsec_conn.
5755                          */
5756                         return;
5757                 }
5758                 ASSERT(econnp->conn_netstack == connp->conn_netstack);
5759         } else {
5760                 goto error2;
5761         }
5762 
5763         ASSERT(DB_TYPE(mp) == M_DATA);
5764 
5765         ipvers = IPH_HDR_VERSION(mp->b_rptr);
5766         ASSERT(ipvers == IPV6_VERSION || ipvers == IPV4_VERSION);
5767         ASSERT(OK_32PTR(mp->b_rptr));
5768         if (ipvers == IPV4_VERSION) {
5769                 ipha = (ipha_t *)mp->b_rptr;
5770                 ip_hdr_len = IPH_HDR_LENGTH(ipha);
5771                 tcph = (tcph_t *)&mp->b_rptr[ip_hdr_len];
5772         } else {
5773                 ip6h = (ip6_t *)mp->b_rptr;
5774                 ip_hdr_len = ip_hdr_length_v6(mp, ip6h);
5775                 tcph = (tcph_t *)&mp->b_rptr[ip_hdr_len];
5776         }
5777 
5778         if (tcp->tcp_family == AF_INET) {
5779                 ASSERT(ipvers == IPV4_VERSION);
5780                 err = tcp_conn_create_v4(connp, econnp, ipha, tcph, mp);
5781         } else {
5782                 err = tcp_conn_create_v6(connp, econnp, mp, tcph, ipvers, mp);
5783         }
5784 
5785         if (err)
5786                 goto error3;
5787 
5788         eager = econnp->conn_tcp;
5789 
5790         /* Inherit various TCP parameters from the listener */
5791         eager->tcp_naglim = tcp->tcp_naglim;
5792         eager->tcp_first_timer_threshold =
5793             tcp->tcp_first_timer_threshold;
5794         eager->tcp_second_timer_threshold =
5795             tcp->tcp_second_timer_threshold;
5796 
5797         eager->tcp_first_ctimer_threshold =
5798             tcp->tcp_first_ctimer_threshold;
5799         eager->tcp_second_ctimer_threshold =
5800             tcp->tcp_second_ctimer_threshold;
5801 
5802         /*
5803          * tcp_adapt_ire() may change tcp_rwnd according to the ire metrics.
5804          * If it does not, the eager's receive window will be set to the
5805          * listener's receive window later in this function.
5806          */
5807         eager->tcp_rwnd = 0;
5808 
5809         /*
5810          * Inherit listener's tcp_init_cwnd.  Need to do this before
5811          * calling tcp_process_options() where tcp_mss_set() is called
5812          * to set the initial cwnd.
5813          */
5814         eager->tcp_init_cwnd = tcp->tcp_init_cwnd;
5815 
5816         /*
5817          * Zones: tcp_adapt_ire() and tcp_send_data() both need the
5818          * zone id before the accept is completed in tcp_wput_accept().
5819          */
5820         econnp->conn_zoneid = connp->conn_zoneid;
5821         econnp->conn_allzones = connp->conn_allzones;
5822 
5823         /* Copy nexthop information from listener to eager */
5824         if (connp->conn_nexthop_set) {
5825                 econnp->conn_nexthop_set = connp->conn_nexthop_set;
5826                 econnp->conn_nexthop_v4 = connp->conn_nexthop_v4;
5827         }
5828 
5829         /*
5830          * TSOL: tsol_input_proc() needs the eager's cred before the
5831          * eager is accepted
5832          */
5833         econnp->conn_cred = eager->tcp_cred = credp = connp->conn_cred;
5834         crhold(credp);
5835 
5836         /*
5837          * If the caller has the process-wide flag set, then default to MAC
5838          * exempt mode.  This allows read-down to unlabeled hosts.
5839          */
5840         if (getpflags(NET_MAC_AWARE, credp) != 0)
5841                 econnp->conn_mac_exempt = B_TRUE;
5842 
5843         if (is_system_labeled()) {
5844                 cred_t *cr;
5845 
5846                 if (connp->conn_mlp_type != mlptSingle) {
5847                         cr = econnp->conn_peercred = DB_CRED(mp);
5848                         if (cr != NULL)
5849                                 crhold(cr);
5850                         else
5851                                 cr = econnp->conn_cred;
5852                         DTRACE_PROBE2(mlp_syn_accept, conn_t *,
5853                             econnp, cred_t *, cr)
5854                 } else {
5855                         cr = econnp->conn_cred;
5856                         DTRACE_PROBE2(syn_accept, conn_t *,
5857                             econnp, cred_t *, cr)
5858                 }
5859 
5860                 if (!tcp_update_label(eager, cr)) {
5861                         DTRACE_PROBE3(
5862                             tx__ip__log__error__connrequest__tcp,
5863                             char *, "eager connp(1) label on SYN mp(2) failed",
5864                             conn_t *, econnp, mblk_t *, mp);
5865                         goto error3;
5866                 }
5867         }
5868 
5869         eager->tcp_hard_binding = B_TRUE;
5870 
5871         tcp_bind_hash_insert(&tcps->tcps_bind_fanout[
5872             TCP_BIND_HASH(eager->tcp_lport)], eager, 0);
5873 
5874         CL_INET_CONNECT(eager);
5875 
5876         /*
5877          * No need to check for multicast destination since ip will only pass
5878          * up multicasts to those that have expressed interest
5879          * TODO: what about rejecting broadcasts?
5880          * Also check that source is not a multicast or broadcast address.
5881          */
5882         eager->tcp_state = TCPS_SYN_RCVD;
5883 
5884 
5885         /*
5886          * There should be no ire in the mp as we are being called after
5887          * receiving the SYN.
5888          */
5889         ASSERT(tcp_ire_mp(mp) == NULL);
5890 
5891         /*
5892          * Adapt our mss, ttl, ... according to information provided in IRE.
5893          */
5894 
5895         if (tcp_adapt_ire(eager, NULL) == 0) {
5896                 /* Undo the bind_hash_insert */
5897                 tcp_bind_hash_remove(eager);
5898                 goto error3;
5899         }
5900 
5901         /* Process all TCP options. */
5902         tcp_process_options(eager, tcph);
5903 
5904         /* Is the other end ECN capable? */
5905         if (tcps->tcps_ecn_permitted >= 1 &&
5906             (tcph->th_flags[0] & (TH_ECE|TH_CWR)) == (TH_ECE|TH_CWR)) {
5907                 eager->tcp_ecn_ok = B_TRUE;
5908         }
5909 
5910         /*
5911          * listener->tcp_rq->q_hiwat should be the default window size or a
5912          * window size changed via SO_RCVBUF option.  First round up the
5913          * eager's tcp_rwnd to the nearest MSS.  Then find out the window
5914          * scale option value if needed.  Call tcp_rwnd_set() to finish the
5915          * setting.
5916          *
5917          * Note if there is a rpipe metric associated with the remote host,
5918          * we should not inherit receive window size from listener.
5919          */
5920         eager->tcp_rwnd = MSS_ROUNDUP(
5921             (eager->tcp_rwnd == 0 ? tcp->tcp_rq->q_hiwat :
5922             eager->tcp_rwnd), eager->tcp_mss);
5923         if (eager->tcp_snd_ws_ok)
5924                 tcp_set_ws_value(eager);
5925         /*
5926          * Note that this is the only place tcp_rwnd_set() is called for
5927          * accepting a connection.  We need to call it here instead of
5928          * after the 3-way handshake because we need to tell the other
5929          * side our rwnd in the SYN-ACK segment.
5930          */
5931         (void) tcp_rwnd_set(eager, eager->tcp_rwnd);
5932 
5933         /*
5934          * We eliminate the need for sockfs to send down a T_SVR4_OPTMGMT_REQ
5935          * via soaccept()->soinheritoptions() which essentially applies
5936          * all the listener options to the new STREAM. The options that we
5937          * need to take care of are:
5938          * SO_DEBUG, SO_REUSEADDR, SO_KEEPALIVE, SO_DONTROUTE, SO_BROADCAST,
5939          * SO_USELOOPBACK, SO_OOBINLINE, SO_DGRAM_ERRIND, SO_LINGER,
5940          * SO_SNDBUF, SO_RCVBUF.
5941          *
5942          * SO_RCVBUF:   tcp_rwnd_set() above takes care of it.
5943          * SO_SNDBUF:   Set the tcp_xmit_hiwater for the eager. When
5944          *              tcp_maxpsz_set() gets called later from
5945          *              tcp_accept_finish(), the option takes effect.
5946          *
5947          */
5948         /* Set the TCP options */
5949         eager->tcp_xmit_hiwater = tcp->tcp_xmit_hiwater;
5950         eager->tcp_dgram_errind = tcp->tcp_dgram_errind;
5951         eager->tcp_oobinline = tcp->tcp_oobinline;
5952         eager->tcp_reuseaddr = tcp->tcp_reuseaddr;
5953         eager->tcp_broadcast = tcp->tcp_broadcast;
5954         eager->tcp_useloopback = tcp->tcp_useloopback;
5955         eager->tcp_dontroute = tcp->tcp_dontroute;
5956         eager->tcp_linger = tcp->tcp_linger;
5957         eager->tcp_lingertime = tcp->tcp_lingertime;
5958         if (tcp->tcp_ka_enabled)
5959                 eager->tcp_ka_enabled = 1;
5960 
5961         /* Set the IP options */
5962         econnp->conn_broadcast = connp->conn_broadcast;
5963         econnp->conn_loopback = connp->conn_loopback;
5964         econnp->conn_dontroute = connp->conn_dontroute;
5965         econnp->conn_reuseaddr = connp->conn_reuseaddr;
5966 
5967         /* Put a ref on the listener for the eager. */
5968         CONN_INC_REF(connp);
5969         mutex_enter(&tcp->tcp_eager_lock);
5970         tcp->tcp_eager_next_q0->tcp_eager_prev_q0 = eager;
5971         eager->tcp_eager_next_q0 = tcp->tcp_eager_next_q0;
5972         tcp->tcp_eager_next_q0 = eager;
5973         eager->tcp_eager_prev_q0 = tcp;
5974 
5975         /* Set tcp_listener before adding it to tcp_conn_fanout */
5976         eager->tcp_listener = tcp;
5977         eager->tcp_saved_listener = tcp;
5978 
5979         /*
5980          * Tag this detached tcp vector for later retrieval
5981          * by our listener client in tcp_accept().
5982          */
5983         eager->tcp_conn_req_seqnum = tcp->tcp_conn_req_seqnum;
5984         tcp->tcp_conn_req_cnt_q0++;
5985         if (++tcp->tcp_conn_req_seqnum == -1) {
5986                 /*
5987                  * -1 is "special" and defined in TPI as something
5988                  * that should never be used in T_CONN_IND
5989                  */
5990                 ++tcp->tcp_conn_req_seqnum;
5991         }
5992         mutex_exit(&tcp->tcp_eager_lock);
5993 
5994         if (tcp->tcp_syn_defense) {
5995                 /* Don't drop the SYN that comes from a good IP source */
5996                 ipaddr_t *addr_cache = (ipaddr_t *)(tcp->tcp_ip_addr_cache);
5997                 if (addr_cache != NULL && eager->tcp_remote ==
5998                     addr_cache[IP_ADDR_CACHE_HASH(eager->tcp_remote)]) {
5999                         eager->tcp_dontdrop = B_TRUE;
6000                 }
6001         }
6002 
6003         /*
6004          * We need to insert the eager in its own perimeter but as soon
6005          * as we do that, we expose the eager to the classifier and
6006          * should not touch any field outside the eager's perimeter.
6007          * So do all the work necessary before inserting the eager
6008          * in its own perimeter. Be optimistic that ipcl_conn_insert()
6009          * will succeed but undo everything if it fails.
6010          */
6011         seg_seq = ABE32_TO_U32(tcph->th_seq);
6012         eager->tcp_irs = seg_seq;
6013         eager->tcp_rack = seg_seq;
6014         eager->tcp_rnxt = seg_seq + 1;
6015         U32_TO_ABE32(eager->tcp_rnxt, eager->tcp_tcph->th_ack);
6016         BUMP_MIB(&tcps->tcps_mib, tcpPassiveOpens);
6017         eager->tcp_state = TCPS_SYN_RCVD;
6018         mp1 = tcp_xmit_mp(eager, eager->tcp_xmit_head, eager->tcp_mss,
6019             NULL, NULL, eager->tcp_iss, B_FALSE, NULL, B_FALSE);
6020         if (mp1 == NULL) {
6021                 /*
6022                  * Increment the ref count as we are going to
6023                  * enqueueing an mp in squeue
6024                  */
6025                 CONN_INC_REF(econnp);
6026                 goto error;
6027         }
6028         DB_CPID(mp1) = tcp->tcp_cpid;
6029         eager->tcp_cpid = tcp->tcp_cpid;
6030         eager->tcp_open_time = lbolt64;
6031 
6032         /*
6033          * We need to start the rto timer. In normal case, we start
6034          * the timer after sending the packet on the wire (or at
6035          * least believing that packet was sent by waiting for
6036          * CALL_IP_WPUT() to return). Since this is the first packet
6037          * being sent on the wire for the eager, our initial tcp_rto
6038          * is at least tcp_rexmit_interval_min which is a fairly
6039          * large value to allow the algorithm to adjust slowly to large
6040          * fluctuations of RTT during first few transmissions.
6041          *
6042          * Starting the timer first and then sending the packet in this
6043          * case shouldn't make much difference since tcp_rexmit_interval_min
6044          * is of the order of several 100ms and starting the timer
6045          * first and then sending the packet will result in difference
6046          * of few micro seconds.
6047          *
6048          * Without this optimization, we are forced to hold the fanout
6049          * lock across the ipcl_bind_insert() and sending the packet
6050          * so that we don't race against an incoming packet (maybe RST)
6051          * for this eager.
6052          *
6053          * It is necessary to acquire an extra reference on the eager
6054          * at this point and hold it until after tcp_send_data() to
6055          * ensure against an eager close race.
6056          */
6057 
6058         CONN_INC_REF(eager->tcp_connp);
6059 
6060         TCP_RECORD_TRACE(eager, mp1, TCP_TRACE_SEND_PKT);
6061         TCP_TIMER_RESTART(eager, eager->tcp_rto);
6062 
6063 
6064         /*
6065          * Insert the eager in its own perimeter now. We are ready to deal
6066          * with any packets on eager.
6067          */
6068         if (eager->tcp_ipversion == IPV4_VERSION) {
6069                 if (ipcl_conn_insert(econnp, IPPROTO_TCP, 0, 0, 0) != 0) {
6070                         goto error;
6071                 }
6072         } else {
6073                 if (ipcl_conn_insert_v6(econnp, IPPROTO_TCP, 0, 0, 0, 0) != 0) {
6074                         goto error;
6075                 }
6076         }
6077 
6078         /* mark conn as fully-bound */
6079         econnp->conn_fully_bound = B_TRUE;
6080 
6081         /* Send the SYN-ACK */
6082         tcp_send_data(eager, eager->tcp_wq, mp1);
6083         CONN_DEC_REF(eager->tcp_connp);
6084         freemsg(mp);
6085 
6086         return;
6087 error:
6088         freemsg(mp1);
6089         eager->tcp_closemp_used = B_TRUE;
6090         TCP_DEBUG_GETPCSTACK(eager->tcmp_stk, 15);
6091         squeue_fill(econnp->conn_sqp, &eager->tcp_closemp, tcp_eager_kill,
6092             econnp, SQTAG_TCP_CONN_REQ_2);
6093 
6094         /*
6095          * If a connection already exists, send the mp to that connections so
6096          * that it can be appropriately dealt with.
6097          */
6098         ipst = tcps->tcps_netstack->netstack_ip;
6099 
6100         if ((econnp = ipcl_classify(mp, connp->conn_zoneid, ipst)) != NULL) {
6101                 if (!IPCL_IS_CONNECTED(econnp)) {
6102                         /*
6103                          * Something bad happened. ipcl_conn_insert()
6104                          * failed because a connection already existed
6105                          * in connected hash but we can't find it
6106                          * anymore (someone blew it away). Just
6107                          * free this message and hopefully remote
6108                          * will retransmit at which time the SYN can be
6109                          * treated as a new connection or dealth with
6110                          * a TH_RST if a connection already exists.
6111                          */
6112                         CONN_DEC_REF(econnp);
6113                         freemsg(mp);
6114                 } else {
6115                         squeue_fill(econnp->conn_sqp, mp, tcp_input,
6116                             econnp, SQTAG_TCP_CONN_REQ_1);
6117                 }
6118         } else {
6119                 /* Nobody wants this packet */
6120                 freemsg(mp);
6121         }
6122         return;
6123 error3:
6124         CONN_DEC_REF(econnp);
6125 error2:
6126         freemsg(mp);
6127 }
6128 
6129 /*
6130  * In an ideal case of vertical partition in NUMA architecture, its
6131  * beneficial to have the listener and all the incoming connections
6132  * tied to the same squeue. The other constraint is that incoming
6133  * connections should be tied to the squeue attached to interrupted
6134  * CPU for obvious locality reason so this leaves the listener to
6135  * be tied to the same squeue. Our only problem is that when listener
6136  * is binding, the CPU that will get interrupted by the NIC whose
6137  * IP address the listener is binding to is not even known. So
6138  * the code below allows us to change that binding at the time the
6139  * CPU is interrupted by virtue of incoming connection's squeue.
6140  *
6141  * This is usefull only in case of a listener bound to a specific IP
6142  * address. For other kind of listeners, they get bound the
6143  * very first time and there is no attempt to rebind them.
6144  */
6145 void
6146 tcp_conn_request_unbound(void *arg, mblk_t *mp, void *arg2)
6147 {
6148         conn_t          *connp = (conn_t *)arg;
6149         squeue_t        *sqp = (squeue_t *)arg2;
6150         squeue_t        *new_sqp;
6151         uint32_t        conn_flags;
6152 
6153         if ((mp->b_datap->db_struioflag & STRUIO_EAGER) != 0) {
6154                 new_sqp = (squeue_t *)DB_CKSUMSTART(mp);
6155         } else {
6156                 goto done;
6157         }
6158 
6159         if (connp->conn_fanout == NULL)
6160                 goto done;
6161 
6162         if (!(connp->conn_flags & IPCL_FULLY_BOUND)) {
6163                 mutex_enter(&connp->conn_fanout->connf_lock);
6164                 mutex_enter(&connp->conn_lock);
6165                 /*
6166                  * No one from read or write side can access us now
6167                  * except for already queued packets on this squeue.
6168                  * But since we haven't changed the squeue yet, they
6169                  * can't execute. If they are processed after we have
6170                  * changed the squeue, they are sent back to the
6171                  * correct squeue down below.
6172                  * But a listner close can race with processing of
6173                  * incoming SYN. If incoming SYN processing changes
6174                  * the squeue then the listener close which is waiting
6175                  * to enter the squeue would operate on the wrong
6176                  * squeue. Hence we don't change the squeue here unless
6177                  * the refcount is exactly the minimum refcount. The
6178                  * minimum refcount of 4 is counted as - 1 each for
6179                  * TCP and IP, 1 for being in the classifier hash, and
6180                  * 1 for the mblk being processed.
6181                  */
6182 
6183                 if (connp->conn_ref != 4 ||
6184                     connp->conn_tcp->tcp_state != TCPS_LISTEN) {
6185                         mutex_exit(&connp->conn_lock);
6186                         mutex_exit(&connp->conn_fanout->connf_lock);
6187                         goto done;
6188                 }
6189                 if (connp->conn_sqp != new_sqp) {
6190                         while (connp->conn_sqp != new_sqp)
6191                                 (void) casptr(&connp->conn_sqp, sqp, new_sqp);
6192                 }
6193 
6194                 do {
6195                         conn_flags = connp->conn_flags;
6196                         conn_flags |= IPCL_FULLY_BOUND;
6197                         (void) cas32(&connp->conn_flags, connp->conn_flags,
6198                             conn_flags);
6199                 } while (!(connp->conn_flags & IPCL_FULLY_BOUND));
6200 
6201                 mutex_exit(&connp->conn_fanout->connf_lock);
6202                 mutex_exit(&connp->conn_lock);
6203         }
6204 
6205 done:
6206         if (connp->conn_sqp != sqp) {
6207                 CONN_INC_REF(connp);
6208                 squeue_fill(connp->conn_sqp, mp,
6209                     connp->conn_recv, connp, SQTAG_TCP_CONN_REQ_UNBOUND);
6210         } else {
6211                 tcp_conn_request(connp, mp, sqp);
6212         }
6213 }
6214 
6215 /*
6216  * Successful connect request processing begins when our client passes
6217  * a T_CONN_REQ message into tcp_wput() and ends when tcp_rput() passes
6218  * our T_OK_ACK reply message upstream.  The control flow looks like this:
6219  *   upstream -> tcp_wput() -> tcp_wput_proto() -> tcp_connect() -> IP
6220  *   upstream <- tcp_rput()                <- IP
6221  * After various error checks are completed, tcp_connect() lays
6222  * the target address and port into the composite header template,
6223  * preallocates the T_OK_ACK reply message, construct a full 12 byte bind
6224  * request followed by an IRE request, and passes the three mblk message
6225  * down to IP looking like this:
6226  *   O_T_BIND_REQ for IP  --> IRE req --> T_OK_ACK for our client
6227  * Processing continues in tcp_rput() when we receive the following message:
6228  *   T_BIND_ACK from IP --> IRE ack --> T_OK_ACK for our client
6229  * After consuming the first two mblks, tcp_rput() calls tcp_timer(),
6230  * to fire off the connection request, and then passes the T_OK_ACK mblk
6231  * upstream that we filled in below.  There are, of course, numerous
6232  * error conditions along the way which truncate the processing described
6233  * above.
6234  */
6235 static void
6236 tcp_connect(tcp_t *tcp, mblk_t *mp)
6237 {
6238         sin_t           *sin;
6239         sin6_t          *sin6;
6240         queue_t         *q = tcp->tcp_wq;
6241         struct T_conn_req       *tcr;
6242         ipaddr_t        *dstaddrp;
6243         in_port_t       dstport;
6244         uint_t          srcid;
6245 
6246         tcr = (struct T_conn_req *)mp->b_rptr;
6247 
6248         ASSERT((uintptr_t)(mp->b_wptr - mp->b_rptr) <= (uintptr_t)INT_MAX);
6249         if ((mp->b_wptr - mp->b_rptr) < sizeof (*tcr)) {
6250                 tcp_err_ack(tcp, mp, TPROTO, 0);
6251                 return;
6252         }
6253 
6254         /*
6255          * Determine packet type based on type of address passed in
6256          * the request should contain an IPv4 or IPv6 address.
6257          * Make sure that address family matches the type of
6258          * family of the the address passed down
6259          */
6260         switch (tcr->DEST_length) {
6261         default:
6262                 tcp_err_ack(tcp, mp, TBADADDR, 0);
6263                 return;
6264 
6265         case (sizeof (sin_t) - sizeof (sin->sin_zero)): {
6266                 /*
6267                  * XXX: The check for valid DEST_length was not there
6268                  * in earlier releases and some buggy
6269                  * TLI apps (e.g Sybase) got away with not feeding
6270                  * in sin_zero part of address.
6271                  * We allow that bug to keep those buggy apps humming.
6272                  * Test suites require the check on DEST_length.
6273                  * We construct a new mblk with valid DEST_length
6274                  * free the original so the rest of the code does
6275                  * not have to keep track of this special shorter
6276                  * length address case.
6277                  */
6278                 mblk_t *nmp;
6279                 struct T_conn_req *ntcr;
6280                 sin_t *nsin;
6281 
6282                 nmp = allocb(sizeof (struct T_conn_req) + sizeof (sin_t) +
6283                     tcr->OPT_length, BPRI_HI);
6284                 if (nmp == NULL) {
6285                         tcp_err_ack(tcp, mp, TSYSERR, ENOMEM);
6286                         return;
6287                 }
6288                 ntcr = (struct T_conn_req *)nmp->b_rptr;
6289                 bzero(ntcr, sizeof (struct T_conn_req)); /* zero fill */
6290                 ntcr->PRIM_type = T_CONN_REQ;
6291                 ntcr->DEST_length = sizeof (sin_t);
6292                 ntcr->DEST_offset = sizeof (struct T_conn_req);
6293 
6294                 nsin = (sin_t *)((uchar_t *)ntcr + ntcr->DEST_offset);
6295                 *nsin = sin_null;
6296                 /* Get pointer to shorter address to copy from original mp */
6297                 sin = (sin_t *)mi_offset_param(mp, tcr->DEST_offset,
6298                     tcr->DEST_length); /* extract DEST_length worth of sin_t */
6299                 if (sin == NULL || !OK_32PTR((char *)sin)) {
6300                         freemsg(nmp);
6301                         tcp_err_ack(tcp, mp, TSYSERR, EINVAL);
6302                         return;
6303                 }
6304                 nsin->sin_family = sin->sin_family;
6305                 nsin->sin_port = sin->sin_port;
6306                 nsin->sin_addr = sin->sin_addr;
6307                 /* Note:nsin->sin_zero zero-fill with sin_null assign above */
6308                 nmp->b_wptr = (uchar_t *)&nsin[1];
6309                 if (tcr->OPT_length != 0) {
6310                         ntcr->OPT_length = tcr->OPT_length;
6311                         ntcr->OPT_offset = nmp->b_wptr - nmp->b_rptr;
6312                         bcopy((uchar_t *)tcr + tcr->OPT_offset,
6313                             (uchar_t *)ntcr + ntcr->OPT_offset,
6314                             tcr->OPT_length);
6315                         nmp->b_wptr += tcr->OPT_length;
6316                 }
6317                 freemsg(mp);    /* original mp freed */
6318                 mp = nmp;       /* re-initialize original variables */
6319                 tcr = ntcr;
6320         }
6321         /* FALLTHRU */
6322 
6323         case sizeof (sin_t):
6324                 sin = (sin_t *)mi_offset_param(mp, tcr->DEST_offset,
6325                     sizeof (sin_t));
6326                 if (sin == NULL || !OK_32PTR((char *)sin)) {
6327                         tcp_err_ack(tcp, mp, TSYSERR, EINVAL);
6328                         return;
6329                 }
6330                 if (tcp->tcp_family != AF_INET ||
6331                     sin->sin_family != AF_INET) {
6332                         tcp_err_ack(tcp, mp, TSYSERR, EAFNOSUPPORT);
6333                         return;
6334                 }
6335                 if (sin->sin_port == 0) {
6336                         tcp_err_ack(tcp, mp, TBADADDR, 0);
6337                         return;
6338                 }
6339                 if (tcp->tcp_connp && tcp->tcp_connp->conn_ipv6_v6only) {
6340                         tcp_err_ack(tcp, mp, TSYSERR, EAFNOSUPPORT);
6341                         return;
6342                 }
6343 
6344                 break;
6345 
6346         case sizeof (sin6_t):
6347                 sin6 = (sin6_t *)mi_offset_param(mp, tcr->DEST_offset,
6348                     sizeof (sin6_t));
6349                 if (sin6 == NULL || !OK_32PTR((char *)sin6)) {
6350                         tcp_err_ack(tcp, mp, TSYSERR, EINVAL);
6351                         return;
6352                 }
6353                 if (tcp->tcp_family != AF_INET6 ||
6354                     sin6->sin6_family != AF_INET6) {
6355                         tcp_err_ack(tcp, mp, TSYSERR, EAFNOSUPPORT);
6356                         return;
6357                 }
6358                 if (sin6->sin6_port == 0) {
6359                         tcp_err_ack(tcp, mp, TBADADDR, 0);
6360                         return;
6361                 }
6362                 break;
6363         }
6364         /*
6365          * TODO: If someone in TCPS_TIME_WAIT has this dst/port we
6366          * should key on their sequence number and cut them loose.
6367          */
6368 
6369         /*
6370          * If options passed in, feed it for verification and handling
6371          */
6372         if (tcr->OPT_length != 0) {
6373                 mblk_t  *ok_mp;
6374                 mblk_t  *discon_mp;
6375                 mblk_t  *conn_opts_mp;
6376                 int t_error, sys_error, do_disconnect;
6377 
6378                 conn_opts_mp = NULL;
6379 
6380                 if (tcp_conprim_opt_process(tcp, mp,
6381                     &do_disconnect, &t_error, &sys_error) < 0) {
6382                         if (do_disconnect) {
6383                                 ASSERT(t_error == 0 && sys_error == 0);
6384                                 discon_mp = mi_tpi_discon_ind(NULL,
6385                                     ECONNREFUSED, 0);
6386                                 if (!discon_mp) {
6387                                         tcp_err_ack_prim(tcp, mp, T_CONN_REQ,
6388                                             TSYSERR, ENOMEM);
6389                                         return;
6390                                 }
6391                                 ok_mp = mi_tpi_ok_ack_alloc(mp);
6392                                 if (!ok_mp) {
6393                                         tcp_err_ack_prim(tcp, NULL, T_CONN_REQ,
6394                                             TSYSERR, ENOMEM);
6395                                         return;
6396                                 }
6397                                 qreply(q, ok_mp);
6398                                 qreply(q, discon_mp); /* no flush! */
6399                         } else {
6400                                 ASSERT(t_error != 0);
6401                                 tcp_err_ack_prim(tcp, mp, T_CONN_REQ, t_error,
6402                                     sys_error);
6403                         }
6404                         return;
6405                 }
6406                 /*
6407                  * Success in setting options, the mp option buffer represented
6408                  * by OPT_length/offset has been potentially modified and
6409                  * contains results of option processing. We copy it in
6410                  * another mp to save it for potentially influencing returning
6411                  * it in T_CONN_CONN.
6412                  */
6413                 if (tcr->OPT_length != 0) { /* there are resulting options */
6414                         conn_opts_mp = copyb(mp);
6415                         if (!conn_opts_mp) {
6416                                 tcp_err_ack_prim(tcp, mp, T_CONN_REQ,
6417                                     TSYSERR, ENOMEM);
6418                                 return;
6419                         }
6420                         ASSERT(tcp->tcp_conn.tcp_opts_conn_req == NULL);
6421                         tcp->tcp_conn.tcp_opts_conn_req = conn_opts_mp;
6422                         /*
6423                          * Note:
6424                          * These resulting option negotiation can include any
6425                          * end-to-end negotiation options but there no such
6426                          * thing (yet?) in our TCP/IP.
6427                          */
6428                 }
6429         }
6430 
6431         /*
6432          * If we're connecting to an IPv4-mapped IPv6 address, we need to
6433          * make sure that the template IP header in the tcp structure is an
6434          * IPv4 header, and that the tcp_ipversion is IPV4_VERSION.  We
6435          * need to this before we call tcp_bindi() so that the port lookup
6436          * code will look for ports in the correct port space (IPv4 and
6437          * IPv6 have separate port spaces).
6438          */
6439         if (tcp->tcp_family == AF_INET6 && tcp->tcp_ipversion == IPV6_VERSION &&
6440             IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
6441                 int err = 0;
6442 
6443                 err = tcp_header_init_ipv4(tcp);
6444                 if (err != 0) {
6445                         mp = mi_tpi_err_ack_alloc(mp, TSYSERR, ENOMEM);
6446                         goto connect_failed;
6447                 }
6448                 if (tcp->tcp_lport != 0)
6449                         *(uint16_t *)tcp->tcp_tcph->th_lport = tcp->tcp_lport;
6450         }
6451 
6452         if (tcp->tcp_issocket) {
6453                 /*
6454                  * TCP is _D_SODIRECT and sockfs is directly above so save
6455                  * the shared sonode sodirect_t pointer (if any) to enable
6456                  * TCP sodirect.
6457                  */
6458                 tcp->tcp_sodirect = SOD_QTOSODP(tcp->tcp_rq);
6459         }
6460 
6461         switch (tcp->tcp_state) {
6462         case TCPS_IDLE:
6463                 /*
6464                  * We support quick connect, refer to comments in
6465                  * tcp_connect_*()
6466                  */
6467                 /* FALLTHRU */
6468         case TCPS_BOUND:
6469         case TCPS_LISTEN:
6470                 if (tcp->tcp_family == AF_INET6) {
6471                         if (!IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
6472                                 tcp_connect_ipv6(tcp, mp,
6473                                     &sin6->sin6_addr,
6474                                     sin6->sin6_port, sin6->sin6_flowinfo,
6475                                     sin6->__sin6_src_id, sin6->sin6_scope_id);
6476                                 return;
6477                         }
6478                         /*
6479                          * Destination adress is mapped IPv6 address.
6480                          * Source bound address should be unspecified or
6481                          * IPv6 mapped address as well.
6482                          */
6483                         if (!IN6_IS_ADDR_UNSPECIFIED(
6484                             &tcp->tcp_bound_source_v6) &&
6485                             !IN6_IS_ADDR_V4MAPPED(&tcp->tcp_bound_source_v6)) {
6486                                 mp = mi_tpi_err_ack_alloc(mp, TSYSERR,
6487                                     EADDRNOTAVAIL);
6488                                 break;
6489                         }
6490                         dstaddrp = &V4_PART_OF_V6((sin6->sin6_addr));
6491                         dstport = sin6->sin6_port;
6492                         srcid = sin6->__sin6_src_id;
6493                 } else {
6494                         dstaddrp = &sin->sin_addr.s_addr;
6495                         dstport = sin->sin_port;
6496                         srcid = 0;
6497                 }
6498 
6499                 tcp_connect_ipv4(tcp, mp, dstaddrp, dstport, srcid);
6500                 return;
6501         default:
6502                 mp = mi_tpi_err_ack_alloc(mp, TOUTSTATE, 0);
6503                 break;
6504         }
6505         /*
6506          * Note: Code below is the "failure" case
6507          */
6508         /* return error ack and blow away saved option results if any */
6509 connect_failed:
6510         if (mp != NULL)
6511                 putnext(tcp->tcp_rq, mp);
6512         else {
6513                 tcp_err_ack_prim(tcp, NULL, T_CONN_REQ,
6514                     TSYSERR, ENOMEM);
6515         }
6516         if (tcp->tcp_conn.tcp_opts_conn_req != NULL)
6517                 tcp_close_mpp(&tcp->tcp_conn.tcp_opts_conn_req);
6518 }
6519 
6520 /*
6521  * Handle connect to IPv4 destinations, including connections for AF_INET6
6522  * sockets connecting to IPv4 mapped IPv6 destinations.
6523  */
6524 static void
6525 tcp_connect_ipv4(tcp_t *tcp, mblk_t *mp, ipaddr_t *dstaddrp, in_port_t dstport,
6526     uint_t srcid)
6527 {
6528         tcph_t  *tcph;
6529         mblk_t  *mp1;
6530         ipaddr_t dstaddr = *dstaddrp;
6531         int32_t oldstate;
6532         uint16_t lport;
6533         tcp_stack_t     *tcps = tcp->tcp_tcps;
6534 
6535         ASSERT(tcp->tcp_ipversion == IPV4_VERSION);
6536 
6537         /* Check for attempt to connect to INADDR_ANY */
6538         if (dstaddr == INADDR_ANY)  {
6539                 /*
6540                  * SunOS 4.x and 4.3 BSD allow an application
6541                  * to connect a TCP socket to INADDR_ANY.
6542                  * When they do this, the kernel picks the
6543                  * address of one interface and uses it
6544                  * instead.  The kernel usually ends up
6545                  * picking the address of the loopback
6546                  * interface.  This is an undocumented feature.
6547                  * However, we provide the same thing here
6548                  * in order to have source and binary
6549                  * compatibility with SunOS 4.x.
6550                  * Update the T_CONN_REQ (sin/sin6) since it is used to
6551                  * generate the T_CONN_CON.
6552                  */
6553                 dstaddr = htonl(INADDR_LOOPBACK);
6554                 *dstaddrp = dstaddr;
6555         }
6556 
6557         /* Handle __sin6_src_id if socket not bound to an IP address */
6558         if (srcid != 0 && tcp->tcp_ipha->ipha_src == INADDR_ANY) {
6559                 ip_srcid_find_id(srcid, &tcp->tcp_ip_src_v6,
6560                     tcp->tcp_connp->conn_zoneid, tcps->tcps_netstack);
6561                 IN6_V4MAPPED_TO_IPADDR(&tcp->tcp_ip_src_v6,
6562                     tcp->tcp_ipha->ipha_src);
6563         }
6564 
6565         /*
6566          * Don't let an endpoint connect to itself.  Note that
6567          * the test here does not catch the case where the
6568          * source IP addr was left unspecified by the user. In
6569          * this case, the source addr is set in tcp_adapt_ire()
6570          * using the reply to the T_BIND message that we send
6571          * down to IP here and the check is repeated in tcp_rput_other.
6572          */
6573         if (dstaddr == tcp->tcp_ipha->ipha_src &&
6574             dstport == tcp->tcp_lport) {
6575                 mp = mi_tpi_err_ack_alloc(mp, TBADADDR, 0);
6576                 goto failed;
6577         }
6578 
6579         tcp->tcp_ipha->ipha_dst = dstaddr;
6580         IN6_IPADDR_TO_V4MAPPED(dstaddr, &tcp->tcp_remote_v6);
6581 
6582         /*
6583          * Massage a source route if any putting the first hop
6584          * in iph_dst. Compute a starting value for the checksum which
6585          * takes into account that the original iph_dst should be
6586          * included in the checksum but that ip will include the
6587          * first hop in the source route in the tcp checksum.
6588          */
6589         tcp->tcp_sum = ip_massage_options(tcp->tcp_ipha, tcps->tcps_netstack);
6590         tcp->tcp_sum = (tcp->tcp_sum & 0xFFFF) + (tcp->tcp_sum >> 16);
6591         tcp->tcp_sum -= ((tcp->tcp_ipha->ipha_dst >> 16) +
6592             (tcp->tcp_ipha->ipha_dst & 0xffff));
6593         if ((int)tcp->tcp_sum < 0)
6594                 tcp->tcp_sum--;
6595         tcp->tcp_sum = (tcp->tcp_sum & 0xFFFF) + (tcp->tcp_sum >> 16);
6596         tcp->tcp_sum = ntohs((tcp->tcp_sum & 0xFFFF) +
6597             (tcp->tcp_sum >> 16));
6598         tcph = tcp->tcp_tcph;
6599         *(uint16_t *)tcph->th_fport = dstport;
6600         tcp->tcp_fport = dstport;
6601 
6602         oldstate = tcp->tcp_state;
6603         /*
6604          * At this point the remote destination address and remote port fields
6605          * in the tcp-four-tuple have been filled in the tcp structure. Now we
6606          * have to see which state tcp was in so we can take apropriate action.
6607          */
6608         if (oldstate == TCPS_IDLE) {
6609                 /*
6610                  * We support a quick connect capability here, allowing
6611                  * clients to transition directly from IDLE to SYN_SENT
6612                  * tcp_bindi will pick an unused port, insert the connection
6613                  * in the bind hash and transition to BOUND state.
6614                  */
6615                 lport = tcp_update_next_port(tcps->tcps_next_port_to_try,
6616                     tcp, B_TRUE);
6617                 lport = tcp_bindi(tcp, lport, &tcp->tcp_ip_src_v6, 0, B_TRUE,
6618                     B_FALSE, B_FALSE);
6619                 if (lport == 0) {
6620                         mp = mi_tpi_err_ack_alloc(mp, TNOADDR, 0);
6621                         goto failed;
6622                 }
6623         }
6624         tcp->tcp_state = TCPS_SYN_SENT;
6625 
6626         /*
6627          * TODO: allow data with connect requests
6628          * by unlinking M_DATA trailers here and
6629          * linking them in behind the T_OK_ACK mblk.
6630          * The tcp_rput() bind ack handler would then
6631          * feed them to tcp_wput_data() rather than call
6632          * tcp_timer().
6633          */
6634         mp = mi_tpi_ok_ack_alloc(mp);
6635         if (!mp) {
6636                 tcp->tcp_state = oldstate;
6637                 goto failed;
6638         }
6639         if (tcp->tcp_family == AF_INET) {
6640                 mp1 = tcp_ip_bind_mp(tcp, O_T_BIND_REQ,
6641                     sizeof (ipa_conn_t));
6642         } else {
6643                 mp1 = tcp_ip_bind_mp(tcp, O_T_BIND_REQ,
6644                     sizeof (ipa6_conn_t));
6645         }
6646         if (mp1) {
6647                 /*
6648                  * We need to make sure that the conn_recv is set to a non-null
6649                  * value before we insert the conn_t into the classifier table.
6650                  * This is to avoid a race with an incoming packet which does
6651                  * an ipcl_classify().
6652                  */
6653                 tcp->tcp_connp->conn_recv = tcp_input;
6654 
6655                 /* Hang onto the T_OK_ACK for later. */
6656                 linkb(mp1, mp);
6657                 mblk_setcred(mp1, tcp->tcp_cred);
6658                 if (tcp->tcp_family == AF_INET)
6659                         mp1 = ip_bind_v4(tcp->tcp_wq, mp1, tcp->tcp_connp);
6660                 else {
6661                         mp1 = ip_bind_v6(tcp->tcp_wq, mp1, tcp->tcp_connp,
6662                             &tcp->tcp_sticky_ipp);
6663                 }
6664                 BUMP_MIB(&tcps->tcps_mib, tcpActiveOpens);
6665                 tcp->tcp_active_open = 1;
6666                 /*
6667                  * If the bind cannot complete immediately
6668                  * IP will arrange to call tcp_rput_other
6669                  * when the bind completes.
6670                  */
6671                 if (mp1 != NULL)
6672                         tcp_rput_other(tcp, mp1);
6673                 return;
6674         }
6675         /* Error case */
6676         tcp->tcp_state = oldstate;
6677         mp = mi_tpi_err_ack_alloc(mp, TSYSERR, ENOMEM);
6678 
6679 failed:
6680         /* return error ack and blow away saved option results if any */
6681         if (mp != NULL)
6682                 putnext(tcp->tcp_rq, mp);
6683         else {
6684                 tcp_err_ack_prim(tcp, NULL, T_CONN_REQ,
6685                     TSYSERR, ENOMEM);
6686         }
6687         if (tcp->tcp_conn.tcp_opts_conn_req != NULL)
6688                 tcp_close_mpp(&tcp->tcp_conn.tcp_opts_conn_req);
6689 
6690 }
6691 
6692 /*
6693  * Handle connect to IPv6 destinations.
6694  */
6695 static void
6696 tcp_connect_ipv6(tcp_t *tcp, mblk_t *mp, in6_addr_t *dstaddrp,
6697     in_port_t dstport, uint32_t flowinfo, uint_t srcid, uint32_t scope_id)
6698 {
6699         tcph_t  *tcph;
6700         mblk_t  *mp1;
6701         ip6_rthdr_t *rth;
6702         int32_t  oldstate;
6703         uint16_t lport;
6704         tcp_stack_t     *tcps = tcp->tcp_tcps;
6705 
6706         ASSERT(tcp->tcp_family == AF_INET6);
6707 
6708         /*
6709          * If we're here, it means that the destination address is a native
6710          * IPv6 address.  Return an error if tcp_ipversion is not IPv6.  A
6711          * reason why it might not be IPv6 is if the socket was bound to an
6712          * IPv4-mapped IPv6 address.
6713          */
6714         if (tcp->tcp_ipversion != IPV6_VERSION) {
6715                 mp = mi_tpi_err_ack_alloc(mp, TBADADDR, 0);
6716                 goto failed;
6717         }
6718 
6719         /*
6720          * Interpret a zero destination to mean loopback.
6721          * Update the T_CONN_REQ (sin/sin6) since it is used to
6722          * generate the T_CONN_CON.
6723          */
6724         if (IN6_IS_ADDR_UNSPECIFIED(dstaddrp)) {
6725                 *dstaddrp = ipv6_loopback;
6726         }
6727 
6728         /* Handle __sin6_src_id if socket not bound to an IP address */
6729         if (srcid != 0 && IN6_IS_ADDR_UNSPECIFIED(&tcp->tcp_ip6h->ip6_src)) {
6730                 ip_srcid_find_id(srcid, &tcp->tcp_ip6h->ip6_src,
6731                     tcp->tcp_connp->conn_zoneid, tcps->tcps_netstack);
6732                 tcp->tcp_ip_src_v6 = tcp->tcp_ip6h->ip6_src;
6733         }
6734 
6735         /*
6736          * Take care of the scope_id now and add ip6i_t
6737          * if ip6i_t is not already allocated through TCP
6738          * sticky options. At this point tcp_ip6h does not
6739          * have dst info, thus use dstaddrp.
6740          */
6741         if (scope_id != 0 &&
6742             IN6_IS_ADDR_LINKSCOPE(dstaddrp)) {
6743                 ip6_pkt_t *ipp = &tcp->tcp_sticky_ipp;
6744                 ip6i_t  *ip6i;
6745 
6746                 ipp->ipp_ifindex = scope_id;
6747                 ip6i = (ip6i_t *)tcp->tcp_iphc;
6748 
6749                 if ((ipp->ipp_fields & IPPF_HAS_IP6I) &&
6750                     ip6i != NULL && (ip6i->ip6i_nxt == IPPROTO_RAW)) {
6751                         /* Already allocated */
6752                         ip6i->ip6i_flags |= IP6I_IFINDEX;
6753                         ip6i->ip6i_ifindex = ipp->ipp_ifindex;
6754                         ipp->ipp_fields |= IPPF_SCOPE_ID;
6755                 } else {
6756                         int reterr;
6757 
6758                         ipp->ipp_fields |= IPPF_SCOPE_ID;
6759                         if (ipp->ipp_fields & IPPF_HAS_IP6I)
6760                                 ip2dbg(("tcp_connect_v6: SCOPE_ID set\n"));
6761                         reterr = tcp_build_hdrs(tcp->tcp_rq, tcp);
6762                         if (reterr != 0)
6763                                 goto failed;
6764                         ip1dbg(("tcp_connect_ipv6: tcp_bld_hdrs returned\n"));
6765                 }
6766         }
6767 
6768         /*
6769          * Don't let an endpoint connect to itself.  Note that
6770          * the test here does not catch the case where the
6771          * source IP addr was left unspecified by the user. In
6772          * this case, the source addr is set in tcp_adapt_ire()
6773          * using the reply to the T_BIND message that we send
6774          * down to IP here and the check is repeated in tcp_rput_other.
6775          */
6776         if (IN6_ARE_ADDR_EQUAL(dstaddrp, &tcp->tcp_ip6h->ip6_src) &&
6777             (dstport == tcp->tcp_lport)) {
6778                 mp = mi_tpi_err_ack_alloc(mp, TBADADDR, 0);
6779                 goto failed;
6780         }
6781 
6782         tcp->tcp_ip6h->ip6_dst = *dstaddrp;
6783         tcp->tcp_remote_v6 = *dstaddrp;
6784         tcp->tcp_ip6h->ip6_vcf =
6785             (IPV6_DEFAULT_VERS_AND_FLOW & IPV6_VERS_AND_FLOW_MASK) |
6786             (flowinfo & ~IPV6_VERS_AND_FLOW_MASK);
6787 
6788 
6789         /*
6790          * Massage a routing header (if present) putting the first hop
6791          * in ip6_dst. Compute a starting value for the checksum which
6792          * takes into account that the original ip6_dst should be
6793          * included in the checksum but that ip will include the
6794          * first hop in the source route in the tcp checksum.
6795          */
6796         rth = ip_find_rthdr_v6(tcp->tcp_ip6h, (uint8_t *)tcp->tcp_tcph);
6797         if (rth != NULL) {
6798                 tcp->tcp_sum = ip_massage_options_v6(tcp->tcp_ip6h, rth,
6799                     tcps->tcps_netstack);
6800                 tcp->tcp_sum = ntohs((tcp->tcp_sum & 0xFFFF) +
6801                     (tcp->tcp_sum >> 16));
6802         } else {
6803                 tcp->tcp_sum = 0;
6804         }
6805 
6806         tcph = tcp->tcp_tcph;
6807         *(uint16_t *)tcph->th_fport = dstport;
6808         tcp->tcp_fport = dstport;
6809 
6810         oldstate = tcp->tcp_state;
6811         /*
6812          * At this point the remote destination address and remote port fields
6813          * in the tcp-four-tuple have been filled in the tcp structure. Now we
6814          * have to see which state tcp was in so we can take apropriate action.
6815          */
6816         if (oldstate == TCPS_IDLE) {
6817                 /*
6818                  * We support a quick connect capability here, allowing
6819                  * clients to transition directly from IDLE to SYN_SENT
6820                  * tcp_bindi will pick an unused port, insert the connection
6821                  * in the bind hash and transition to BOUND state.
6822                  */
6823                 lport = tcp_update_next_port(tcps->tcps_next_port_to_try,
6824                     tcp, B_TRUE);
6825                 lport = tcp_bindi(tcp, lport, &tcp->tcp_ip_src_v6, 0, B_TRUE,
6826                     B_FALSE, B_FALSE);
6827                 if (lport == 0) {
6828                         mp = mi_tpi_err_ack_alloc(mp, TNOADDR, 0);
6829                         goto failed;
6830                 }
6831         }
6832         tcp->tcp_state = TCPS_SYN_SENT;
6833         /*
6834          * TODO: allow data with connect requests
6835          * by unlinking M_DATA trailers here and
6836          * linking them in behind the T_OK_ACK mblk.
6837          * The tcp_rput() bind ack handler would then
6838          * feed them to tcp_wput_data() rather than call
6839          * tcp_timer().
6840          */
6841         mp = mi_tpi_ok_ack_alloc(mp);
6842         if (!mp) {
6843                 tcp->tcp_state = oldstate;
6844                 goto failed;
6845         }
6846         mp1 = tcp_ip_bind_mp(tcp, O_T_BIND_REQ, sizeof (ipa6_conn_t));
6847         if (mp1) {
6848                 /*
6849                  * We need to make sure that the conn_recv is set to a non-null
6850                  * value before we insert the conn_t into the classifier table.
6851                  * This is to avoid a race with an incoming packet which does
6852                  * an ipcl_classify().
6853                  */
6854                 tcp->tcp_connp->conn_recv = tcp_input;
6855 
6856                 /* Hang onto the T_OK_ACK for later. */
6857                 linkb(mp1, mp);
6858                 mblk_setcred(mp1, tcp->tcp_cred);
6859                 mp1 = ip_bind_v6(tcp->tcp_wq, mp1, tcp->tcp_connp,
6860                     &tcp->tcp_sticky_ipp);
6861                 BUMP_MIB(&tcps->tcps_mib, tcpActiveOpens);
6862                 tcp->tcp_active_open = 1;
6863                 /* ip_bind_v6() may return ACK or ERROR */
6864                 if (mp1 != NULL)
6865                         tcp_rput_other(tcp, mp1);
6866                 return;
6867         }
6868         /* Error case */
6869         tcp->tcp_state = oldstate;
6870         mp = mi_tpi_err_ack_alloc(mp, TSYSERR, ENOMEM);
6871 
6872 failed:
6873         /* return error ack and blow away saved option results if any */
6874         if (mp != NULL)
6875                 putnext(tcp->tcp_rq, mp);
6876         else {
6877                 tcp_err_ack_prim(tcp, NULL, T_CONN_REQ,
6878                     TSYSERR, ENOMEM);
6879         }
6880         if (tcp->tcp_conn.tcp_opts_conn_req != NULL)
6881                 tcp_close_mpp(&tcp->tcp_conn.tcp_opts_conn_req);
6882 }
6883 
6884 /*
6885  * We need a stream q for detached closing tcp connections
6886  * to use.  Our client hereby indicates that this q is the
6887  * one to use.
6888  */
6889 static void
6890 tcp_def_q_set(tcp_t *tcp, mblk_t *mp)
6891 {
6892         struct iocblk *iocp = (struct iocblk *)mp->b_rptr;
6893         queue_t *q = tcp->tcp_wq;
6894         tcp_stack_t     *tcps = tcp->tcp_tcps;
6895 
6896 #ifdef NS_DEBUG
6897         (void) printf("TCP_IOC_DEFAULT_Q for stack %d\n",
6898             tcps->tcps_netstack->netstack_stackid);
6899 #endif
6900         mp->b_datap->db_type = M_IOCACK;
6901         iocp->ioc_count = 0;
6902         mutex_enter(&tcps->tcps_g_q_lock);
6903         if (tcps->tcps_g_q != NULL) {
6904                 mutex_exit(&tcps->tcps_g_q_lock);
6905                 iocp->ioc_error = EALREADY;
6906         } else {
6907                 mblk_t *mp1;
6908 
6909                 mp1 = tcp_ip_bind_mp(tcp, O_T_BIND_REQ, 0);
6910                 if (mp1 == NULL) {
6911                         mutex_exit(&tcps->tcps_g_q_lock);
6912                         iocp->ioc_error = ENOMEM;
6913                 } else {
6914                         tcps->tcps_g_q = tcp->tcp_rq;
6915                         mutex_exit(&tcps->tcps_g_q_lock);
6916                         iocp->ioc_error = 0;
6917                         iocp->ioc_rval = 0;
6918                         /*
6919                          * We are passing tcp_sticky_ipp as NULL
6920                          * as it is not useful for tcp_default queue
6921                          *
6922                          * Set conn_recv just in case.
6923                          */
6924                         tcp->tcp_connp->conn_recv = tcp_conn_request;
6925 
6926                         mp1 = ip_bind_v6(q, mp1, tcp->tcp_connp, NULL);
6927                         if (mp1 != NULL)
6928                                 tcp_rput_other(tcp, mp1);
6929                 }
6930         }
6931         qreply(q, mp);
6932 }
6933 
6934 /*
6935  * Our client hereby directs us to reject the connection request
6936  * that tcp_conn_request() marked with 'seqnum'.  Rejection consists
6937  * of sending the appropriate RST, not an ICMP error.
6938  */
6939 static void
6940 tcp_disconnect(tcp_t *tcp, mblk_t *mp)
6941 {
6942         tcp_t   *ltcp = NULL;
6943         t_scalar_t seqnum;
6944         conn_t  *connp;
6945         tcp_stack_t     *tcps = tcp->tcp_tcps;
6946 
6947         ASSERT((uintptr_t)(mp->b_wptr - mp->b_rptr) <= (uintptr_t)INT_MAX);
6948         if ((mp->b_wptr - mp->b_rptr) < sizeof (struct T_discon_req)) {
6949                 tcp_err_ack(tcp, mp, TPROTO, 0);
6950                 return;
6951         }
6952 
6953         /*
6954          * Right now, upper modules pass down a T_DISCON_REQ to TCP,
6955          * when the stream is in BOUND state. Do not send a reset,
6956          * since the destination IP address is not valid, and it can
6957          * be the initialized value of all zeros (broadcast address).
6958          *
6959          * If TCP has sent down a bind request to IP and has not
6960          * received the reply, reject the request.  Otherwise, TCP
6961          * will be confused.
6962          */
6963         if (tcp->tcp_state <= TCPS_BOUND || tcp->tcp_hard_binding) {
6964                 if (tcp->tcp_debug) {
6965                         (void) strlog(TCP_MOD_ID, 0, 1, SL_ERROR|SL_TRACE,
6966                             "tcp_disconnect: bad state, %d", tcp->tcp_state);
6967                 }
6968                 tcp_err_ack(tcp, mp, TOUTSTATE, 0);
6969                 return;
6970         }
6971 
6972         seqnum = ((struct T_discon_req *)mp->b_rptr)->SEQ_number;
6973 
6974         if (seqnum == -1 || tcp->tcp_conn_req_max == 0) {
6975 
6976                 /*
6977                  * According to TPI, for non-listeners, ignore seqnum
6978                  * and disconnect.
6979                  * Following interpretation of -1 seqnum is historical
6980                  * and implied TPI ? (TPI only states that for T_CONN_IND,
6981                  * a valid seqnum should not be -1).
6982                  *
6983                  *      -1 means disconnect everything
6984                  *      regardless even on a listener.
6985                  */
6986 
6987                 int old_state = tcp->tcp_state;
6988                 ip_stack_t *ipst = tcps->tcps_netstack->netstack_ip;
6989 
6990                 /*
6991                  * The connection can't be on the tcp_time_wait_head list
6992                  * since it is not detached.
6993                  */
6994                 ASSERT(tcp->tcp_time_wait_next == NULL);
6995                 ASSERT(tcp->tcp_time_wait_prev == NULL);
6996                 ASSERT(tcp->tcp_time_wait_expire == 0);
6997                 ltcp = NULL;
6998                 /*
6999                  * If it used to be a listener, check to make sure no one else
7000                  * has taken the port before switching back to LISTEN state.
7001                  */
7002                 if (tcp->tcp_ipversion == IPV4_VERSION) {
7003                         connp = ipcl_lookup_listener_v4(tcp->tcp_lport,
7004                             tcp->tcp_ipha->ipha_src,
7005                             tcp->tcp_connp->conn_zoneid, ipst);
7006                         if (connp != NULL)
7007                                 ltcp = connp->conn_tcp;
7008                 } else {
7009                         /* Allow tcp_bound_if listeners? */
7010                         connp = ipcl_lookup_listener_v6(tcp->tcp_lport,
7011                             &tcp->tcp_ip6h->ip6_src, 0,
7012                             tcp->tcp_connp->conn_zoneid, ipst);
7013                         if (connp != NULL)
7014                                 ltcp = connp->conn_tcp;
7015                 }
7016                 if (tcp->tcp_conn_req_max && ltcp == NULL) {
7017                         tcp->tcp_state = TCPS_LISTEN;
7018                 } else if (old_state > TCPS_BOUND) {
7019                         tcp->tcp_conn_req_max = 0;
7020                         tcp->tcp_state = TCPS_BOUND;
7021                 }
7022                 if (ltcp != NULL)
7023                         CONN_DEC_REF(ltcp->tcp_connp);
7024                 if (old_state == TCPS_SYN_SENT || old_state == TCPS_SYN_RCVD) {
7025                         BUMP_MIB(&tcps->tcps_mib, tcpAttemptFails);
7026                 } else if (old_state == TCPS_ESTABLISHED ||
7027                     old_state == TCPS_CLOSE_WAIT) {
7028                         BUMP_MIB(&tcps->tcps_mib, tcpEstabResets);
7029                 }
7030 
7031                 if (tcp->tcp_fused)
7032                         tcp_unfuse(tcp);
7033 
7034                 mutex_enter(&tcp->tcp_eager_lock);
7035                 if ((tcp->tcp_conn_req_cnt_q0 != 0) ||
7036                     (tcp->tcp_conn_req_cnt_q != 0)) {
7037                         tcp_eager_cleanup(tcp, 0);
7038                 }
7039                 mutex_exit(&tcp->tcp_eager_lock);
7040 
7041                 tcp_xmit_ctl("tcp_disconnect", tcp, tcp->tcp_snxt,
7042                     tcp->tcp_rnxt, TH_RST | TH_ACK);
7043 
7044                 tcp_reinit(tcp);
7045 
7046                 if (old_state >= TCPS_ESTABLISHED) {
7047                         /* Send M_FLUSH according to TPI */
7048                         (void) putnextctl1(tcp->tcp_rq, M_FLUSH, FLUSHRW);
7049                 }
7050                 mp = mi_tpi_ok_ack_alloc(mp);
7051                 if (mp)
7052                         putnext(tcp->tcp_rq, mp);
7053                 return;
7054         } else if (!tcp_eager_blowoff(tcp, seqnum)) {
7055                 tcp_err_ack(tcp, mp, TBADSEQ, 0);
7056                 return;
7057         }
7058         if (tcp->tcp_state >= TCPS_ESTABLISHED) {
7059                 /* Send M_FLUSH according to TPI */
7060                 (void) putnextctl1(tcp->tcp_rq, M_FLUSH, FLUSHRW);
7061         }
7062         mp = mi_tpi_ok_ack_alloc(mp);
7063         if (mp)
7064                 putnext(tcp->tcp_rq, mp);
7065 }
7066 
7067 /*
7068  * Diagnostic routine used to return a string associated with the tcp state.
7069  * Note that if the caller does not supply a buffer, it will use an internal
7070  * static string.  This means that if multiple threads call this function at
7071  * the same time, output can be corrupted...  Note also that this function
7072  * does not check the size of the supplied buffer.  The caller has to make
7073  * sure that it is big enough.
7074  */
7075 static char *
7076 tcp_display(tcp_t *tcp, char *sup_buf, char format)
7077 {
7078         char            buf1[30];
7079         static char     priv_buf[INET6_ADDRSTRLEN * 2 + 80];
7080         char            *buf;
7081         char            *cp;
7082         in6_addr_t      local, remote;
7083         char            local_addrbuf[INET6_ADDRSTRLEN];
7084         char            remote_addrbuf[INET6_ADDRSTRLEN];
7085 
7086         if (sup_buf != NULL)
7087                 buf = sup_buf;
7088         else
7089                 buf = priv_buf;
7090 
7091         if (tcp == NULL)
7092                 return ("NULL_TCP");
7093         switch (tcp->tcp_state) {
7094         case TCPS_CLOSED:
7095                 cp = "TCP_CLOSED";
7096                 break;
7097         case TCPS_IDLE:
7098                 cp = "TCP_IDLE";
7099                 break;
7100         case TCPS_BOUND:
7101                 cp = "TCP_BOUND";
7102                 break;
7103         case TCPS_LISTEN:
7104                 cp = "TCP_LISTEN";
7105                 break;
7106         case TCPS_SYN_SENT:
7107                 cp = "TCP_SYN_SENT";
7108                 break;
7109         case TCPS_SYN_RCVD:
7110                 cp = "TCP_SYN_RCVD";
7111                 break;
7112         case TCPS_ESTABLISHED:
7113                 cp = "TCP_ESTABLISHED";
7114                 break;
7115         case TCPS_CLOSE_WAIT:
7116                 cp = "TCP_CLOSE_WAIT";
7117                 break;
7118         case TCPS_FIN_WAIT_1:
7119                 cp = "TCP_FIN_WAIT_1";
7120                 break;
7121         case TCPS_CLOSING:
7122                 cp = "TCP_CLOSING";
7123                 break;
7124         case TCPS_LAST_ACK:
7125                 cp = "TCP_LAST_ACK";
7126                 break;
7127         case TCPS_FIN_WAIT_2:
7128                 cp = "TCP_FIN_WAIT_2";
7129                 break;
7130         case TCPS_TIME_WAIT:
7131                 cp = "TCP_TIME_WAIT";
7132                 break;
7133         default:
7134                 (void) mi_sprintf(buf1, "TCPUnkState(%d)", tcp->tcp_state);
7135                 cp = buf1;
7136                 break;
7137         }
7138         switch (format) {
7139         case DISP_ADDR_AND_PORT:
7140                 if (tcp->tcp_ipversion == IPV4_VERSION) {
7141                         /*
7142                          * Note that we use the remote address in the tcp_b
7143                          * structure.  This means that it will print out
7144                          * the real destination address, not the next hop's
7145                          * address if source routing is used.
7146                          */
7147                         IN6_IPADDR_TO_V4MAPPED(tcp->tcp_ip_src, &local);
7148                         IN6_IPADDR_TO_V4MAPPED(tcp->tcp_remote, &remote);
7149 
7150                 } else {
7151                         local = tcp->tcp_ip_src_v6;
7152                         remote = tcp->tcp_remote_v6;
7153                 }
7154                 (void) inet_ntop(AF_INET6, &local, local_addrbuf,
7155                     sizeof (local_addrbuf));
7156                 (void) inet_ntop(AF_INET6, &remote, remote_addrbuf,
7157                     sizeof (remote_addrbuf));
7158                 (void) mi_sprintf(buf, "[%s.%u, %s.%u] %s",
7159                     local_addrbuf, ntohs(tcp->tcp_lport), remote_addrbuf,
7160                     ntohs(tcp->tcp_fport), cp);
7161                 break;
7162         case DISP_PORT_ONLY:
7163         default:
7164                 (void) mi_sprintf(buf, "[%u, %u] %s",
7165                     ntohs(tcp->tcp_lport), ntohs(tcp->tcp_fport), cp);
7166                 break;
7167         }
7168 
7169         return (buf);
7170 }
7171 
7172 /*
7173  * Called via squeue to get on to eager's perimeter. It sends a
7174  * TH_RST if eager is in the fanout table. The listener wants the
7175  * eager to disappear either by means of tcp_eager_blowoff() or
7176  * tcp_eager_cleanup() being called. tcp_eager_kill() can also be
7177  * called (via squeue) if the eager cannot be inserted in the
7178  * fanout table in tcp_conn_request().
7179  */
7180 /* ARGSUSED */
7181 void
7182 tcp_eager_kill(void *arg, mblk_t *mp, void *arg2)
7183 {
7184         conn_t  *econnp = (conn_t *)arg;
7185         tcp_t   *eager = econnp->conn_tcp;
7186         tcp_t   *listener = eager->tcp_listener;
7187         tcp_stack_t     *tcps = eager->tcp_tcps;
7188 
7189         /*
7190          * We could be called because listener is closing. Since
7191          * the eager is using listener's queue's, its not safe.
7192          * Better use the default queue just to send the TH_RST
7193          * out.
7194          */
7195         ASSERT(tcps->tcps_g_q != NULL);
7196         eager->tcp_rq = tcps->tcps_g_q;
7197         eager->tcp_wq = WR(tcps->tcps_g_q);
7198 
7199         /*
7200          * An eager's conn_fanout will be NULL if it's a duplicate
7201          * for an existing 4-tuples in the conn fanout table.
7202          * We don't want to send an RST out in such case.
7203          */
7204         if (econnp->conn_fanout != NULL && eager->tcp_state > TCPS_LISTEN) {
7205                 tcp_xmit_ctl("tcp_eager_kill, can't wait",
7206                     eager, eager->tcp_snxt, 0, TH_RST);
7207         }
7208 
7209         /* We are here because listener wants this eager gone */
7210         if (listener != NULL) {
7211                 mutex_enter(&listener->tcp_eager_lock);
7212                 tcp_eager_unlink(eager);
7213                 if (eager->tcp_tconnind_started) {
7214                         /*
7215                          * The eager has sent a conn_ind up to the
7216                          * listener but listener decides to close
7217                          * instead. We need to drop the extra ref
7218                          * placed on eager in tcp_rput_data() before
7219                          * sending the conn_ind to listener.
7220                          */
7221                         CONN_DEC_REF(econnp);
7222                 }
7223                 mutex_exit(&listener->tcp_eager_lock);
7224                 CONN_DEC_REF(listener->tcp_connp);
7225         }
7226 
7227         if (eager->tcp_state > TCPS_BOUND)
7228                 tcp_close_detached(eager);
7229 }
7230 
7231 /*
7232  * Reset any eager connection hanging off this listener marked
7233  * with 'seqnum' and then reclaim it's resources.
7234  */
7235 static boolean_t
7236 tcp_eager_blowoff(tcp_t *listener, t_scalar_t seqnum)
7237 {
7238         tcp_t   *eager;
7239         mblk_t  *mp;
7240         tcp_stack_t     *tcps = listener->tcp_tcps;
7241 
7242         TCP_STAT(tcps, tcp_eager_blowoff_calls);
7243         eager = listener;
7244         mutex_enter(&listener->tcp_eager_lock);
7245         do {
7246                 eager = eager->tcp_eager_next_q;
7247                 if (eager == NULL) {
7248                         mutex_exit(&listener->tcp_eager_lock);
7249                         return (B_FALSE);
7250                 }
7251         } while (eager->tcp_conn_req_seqnum != seqnum);
7252 
7253         if (eager->tcp_closemp_used) {
7254                 mutex_exit(&listener->tcp_eager_lock);
7255                 return (B_TRUE);
7256         }
7257         eager->tcp_closemp_used = B_TRUE;
7258         TCP_DEBUG_GETPCSTACK(eager->tcmp_stk, 15);
7259         CONN_INC_REF(eager->tcp_connp);
7260         mutex_exit(&listener->tcp_eager_lock);
7261         mp = &eager->tcp_closemp;
7262         squeue_fill(eager->tcp_connp->conn_sqp, mp, tcp_eager_kill,
7263             eager->tcp_connp, SQTAG_TCP_EAGER_BLOWOFF);
7264         return (B_TRUE);
7265 }
7266 
7267 /*
7268  * Reset any eager connection hanging off this listener
7269  * and then reclaim it's resources.
7270  */
7271 static void
7272 tcp_eager_cleanup(tcp_t *listener, boolean_t q0_only)
7273 {
7274         tcp_t   *eager;
7275         mblk_t  *mp;
7276         tcp_stack_t     *tcps = listener->tcp_tcps;
7277 
7278         ASSERT(MUTEX_HELD(&listener->tcp_eager_lock));
7279 
7280         if (!q0_only) {
7281                 /* First cleanup q */
7282                 TCP_STAT(tcps, tcp_eager_blowoff_q);
7283                 eager = listener->tcp_eager_next_q;
7284                 while (eager != NULL) {
7285                         if (!eager->tcp_closemp_used) {
7286                                 eager->tcp_closemp_used = B_TRUE;
7287                                 TCP_DEBUG_GETPCSTACK(eager->tcmp_stk, 15);
7288                                 CONN_INC_REF(eager->tcp_connp);
7289                                 mp = &eager->tcp_closemp;
7290                                 squeue_fill(eager->tcp_connp->conn_sqp, mp,
7291                                     tcp_eager_kill, eager->tcp_connp,
7292                                     SQTAG_TCP_EAGER_CLEANUP);
7293                         }
7294                         eager = eager->tcp_eager_next_q;
7295                 }
7296         }
7297         /* Then cleanup q0 */
7298         TCP_STAT(tcps, tcp_eager_blowoff_q0);
7299         eager = listener->tcp_eager_next_q0;
7300         while (eager != listener) {
7301                 if (!eager->tcp_closemp_used) {
7302                         eager->tcp_closemp_used = B_TRUE;
7303                         TCP_DEBUG_GETPCSTACK(eager->tcmp_stk, 15);
7304                         CONN_INC_REF(eager->tcp_connp);
7305                         mp = &eager->tcp_closemp;
7306                         squeue_fill(eager->tcp_connp->conn_sqp, mp,
7307                             tcp_eager_kill, eager->tcp_connp,
7308                             SQTAG_TCP_EAGER_CLEANUP_Q0);
7309                 }
7310                 eager = eager->tcp_eager_next_q0;
7311         }
7312 }
7313 
7314 /*
7315  * If we are an eager connection hanging off a listener that hasn't
7316  * formally accepted the connection yet, get off his list and blow off
7317  * any data that we have accumulated.
7318  */
7319 static void
7320 tcp_eager_unlink(tcp_t *tcp)
7321 {
7322         tcp_t   *listener = tcp->tcp_listener;
7323 
7324         ASSERT(MUTEX_HELD(&listener->tcp_eager_lock));
7325         ASSERT(listener != NULL);
7326         if (tcp->tcp_eager_next_q0 != NULL) {
7327                 ASSERT(tcp->tcp_eager_prev_q0 != NULL);
7328 
7329                 /* Remove the eager tcp from q0 */
7330                 tcp->tcp_eager_next_q0->tcp_eager_prev_q0 =
7331                     tcp->tcp_eager_prev_q0;
7332                 tcp->tcp_eager_prev_q0->tcp_eager_next_q0 =
7333                     tcp->tcp_eager_next_q0;
7334                 ASSERT(listener->tcp_conn_req_cnt_q0 > 0);
7335                 listener->tcp_conn_req_cnt_q0--;
7336 
7337                 tcp->tcp_eager_next_q0 = NULL;
7338                 tcp->tcp_eager_prev_q0 = NULL;
7339 
7340                 /*
7341                  * Take the eager out, if it is in the list of droppable
7342                  * eagers.
7343                  */
7344                 MAKE_UNDROPPABLE(tcp);
7345 
7346                 if (tcp->tcp_syn_rcvd_timeout != 0) {
7347                         /* we have timed out before */
7348                         ASSERT(listener->tcp_syn_rcvd_timeout > 0);
7349                         listener->tcp_syn_rcvd_timeout--;
7350                 }
7351         } else {
7352                 tcp_t   **tcpp = &listener->tcp_eager_next_q;
7353                 tcp_t   *prev = NULL;
7354 
7355                 for (; tcpp[0]; tcpp = &tcpp[0]->tcp_eager_next_q) {
7356                         if (tcpp[0] == tcp) {
7357                                 if (listener->tcp_eager_last_q == tcp) {
7358                                         /*
7359                                          * If we are unlinking the last
7360                                          * element on the list, adjust
7361                                          * tail pointer. Set tail pointer
7362                                          * to nil when list is empty.
7363                                          */
7364                                         ASSERT(tcp->tcp_eager_next_q == NULL);
7365                                         if (listener->tcp_eager_last_q ==
7366                                             listener->tcp_eager_next_q) {
7367                                                 listener->tcp_eager_last_q =
7368                                                     NULL;
7369                                         } else {
7370                                                 /*
7371                                                  * We won't get here if there
7372                                                  * is only one eager in the
7373                                                  * list.
7374                                                  */
7375                                                 ASSERT(prev != NULL);
7376                                                 listener->tcp_eager_last_q =
7377                                                     prev;
7378                                         }
7379                                 }
7380                                 tcpp[0] = tcp->tcp_eager_next_q;
7381                                 tcp->tcp_eager_next_q = NULL;
7382                                 tcp->tcp_eager_last_q = NULL;
7383                                 ASSERT(listener->tcp_conn_req_cnt_q > 0);
7384                                 listener->tcp_conn_req_cnt_q--;
7385                                 break;
7386                         }
7387                         prev = tcpp[0];
7388                 }
7389         }
7390         tcp->tcp_listener = NULL;
7391 }
7392 
7393 /* Shorthand to generate and send TPI error acks to our client */
7394 static void
7395 tcp_err_ack(tcp_t *tcp, mblk_t *mp, int t_error, int sys_error)
7396 {
7397         if ((mp = mi_tpi_err_ack_alloc(mp, t_error, sys_error)) != NULL)
7398                 putnext(tcp->tcp_rq, mp);
7399 }
7400 
7401 /* Shorthand to generate and send TPI error acks to our client */
7402 static void
7403 tcp_err_ack_prim(tcp_t *tcp, mblk_t *mp, int primitive,
7404     int t_error, int sys_error)
7405 {
7406         struct T_error_ack      *teackp;
7407 
7408         if ((mp = tpi_ack_alloc(mp, sizeof (struct T_error_ack),
7409             M_PCPROTO, T_ERROR_ACK)) != NULL) {
7410                 teackp = (struct T_error_ack *)mp->b_rptr;
7411                 teackp->ERROR_prim = primitive;
7412                 teackp->TLI_error = t_error;
7413                 teackp->UNIX_error = sys_error;
7414                 putnext(tcp->tcp_rq, mp);
7415         }
7416 }
7417 
7418 /*
7419  * Note: No locks are held when inspecting tcp_g_*epriv_ports
7420  * but instead the code relies on:
7421  * - the fact that the address of the array and its size never changes
7422  * - the atomic assignment of the elements of the array
7423  */
7424 /* ARGSUSED */
7425 static int
7426 tcp_extra_priv_ports_get(queue_t *q, mblk_t *mp, caddr_t cp, cred_t *cr)
7427 {
7428         int i;
7429         tcp_stack_t     *tcps = Q_TO_TCP(q)->tcp_tcps;
7430 
7431         for (i = 0; i < tcps->tcps_g_num_epriv_ports; i++) {
7432                 if (tcps->tcps_g_epriv_ports[i] != 0)
7433                         (void) mi_mpprintf(mp, "%d ",
7434                             tcps->tcps_g_epriv_ports[i]);
7435         }
7436         return (0);
7437 }
7438 
7439 /*
7440  * Hold a lock while changing tcp_g_epriv_ports to prevent multiple
7441  * threads from changing it at the same time.
7442  */
7443 /* ARGSUSED */
7444 static int
7445 tcp_extra_priv_ports_add(queue_t *q, mblk_t *mp, char *value, caddr_t cp,
7446     cred_t *cr)
7447 {
7448         long    new_value;
7449         int     i;
7450         tcp_stack_t     *tcps = Q_TO_TCP(q)->tcp_tcps;
7451 
7452         /*
7453          * Fail the request if the new value does not lie within the
7454          * port number limits.
7455          */
7456         if (ddi_strtol(value, NULL, 10, &new_value) != 0 ||
7457             new_value <= 0 || new_value >= 65536) {
7458                 return (EINVAL);
7459         }
7460 
7461         mutex_enter(&tcps->tcps_epriv_port_lock);
7462         /* Check if the value is already in the list */
7463         for (i = 0; i < tcps->tcps_g_num_epriv_ports; i++) {
7464                 if (new_value == tcps->tcps_g_epriv_ports[i]) {
7465                         mutex_exit(&tcps->tcps_epriv_port_lock);
7466                         return (EEXIST);
7467                 }
7468         }
7469         /* Find an empty slot */
7470         for (i = 0; i < tcps->tcps_g_num_epriv_ports; i++) {
7471                 if (tcps->tcps_g_epriv_ports[i] == 0)
7472                         break;
7473         }
7474         if (i == tcps->tcps_g_num_epriv_ports) {
7475                 mutex_exit(&tcps->tcps_epriv_port_lock);
7476                 return (EOVERFLOW);
7477         }
7478         /* Set the new value */
7479         tcps->tcps_g_epriv_ports[i] = (uint16_t)new_value;
7480         mutex_exit(&tcps->tcps_epriv_port_lock);
7481         return (0);
7482 }
7483 
7484 /*
7485  * Hold a lock while changing tcp_g_epriv_ports to prevent multiple
7486  * threads from changing it at the same time.
7487  */
7488 /* ARGSUSED */
7489 static int
7490 tcp_extra_priv_ports_del(queue_t *q, mblk_t *mp, char *value, caddr_t cp,
7491     cred_t *cr)
7492 {
7493         long    new_value;
7494         int     i;
7495         tcp_stack_t     *tcps = Q_TO_TCP(q)->tcp_tcps;
7496 
7497         /*
7498          * Fail the request if the new value does not lie within the
7499          * port number limits.
7500          */
7501         if (ddi_strtol(value, NULL, 10, &new_value) != 0 || new_value <= 0 ||
7502             new_value >= 65536) {
7503                 return (EINVAL);
7504         }
7505 
7506         mutex_enter(&tcps->tcps_epriv_port_lock);
7507         /* Check that the value is already in the list */
7508         for (i = 0; i < tcps->tcps_g_num_epriv_ports; i++) {
7509                 if (tcps->tcps_g_epriv_ports[i] == new_value)
7510                         break;
7511         }
7512         if (i == tcps->tcps_g_num_epriv_ports) {
7513                 mutex_exit(&tcps->tcps_epriv_port_lock);
7514                 return (ESRCH);
7515         }
7516         /* Clear the value */
7517         tcps->tcps_g_epriv_ports[i] = 0;
7518         mutex_exit(&tcps->tcps_epriv_port_lock);
7519         return (0);
7520 }
7521 
7522 /* Return the TPI/TLI equivalent of our current tcp_state */
7523 static int
7524 tcp_tpistate(tcp_t *tcp)
7525 {
7526         switch (tcp->tcp_state) {
7527         case TCPS_IDLE:
7528                 return (TS_UNBND);
7529         case TCPS_LISTEN:
7530                 /*
7531                  * Return whether there are outstanding T_CONN_IND waiting
7532                  * for the matching T_CONN_RES. Therefore don't count q0.
7533                  */
7534                 if (tcp->tcp_conn_req_cnt_q > 0)
7535                         return (TS_WRES_CIND);
7536                 else
7537                         return (TS_IDLE);
7538         case TCPS_BOUND:
7539                 return (TS_IDLE);
7540         case TCPS_SYN_SENT:
7541                 return (TS_WCON_CREQ);
7542         case TCPS_SYN_RCVD:
7543                 /*
7544                  * Note: assumption: this has to the active open SYN_RCVD.
7545                  * The passive instance is detached in SYN_RCVD stage of
7546                  * incoming connection processing so we cannot get request
7547                  * for T_info_ack on it.
7548                  */
7549                 return (TS_WACK_CRES);
7550         case TCPS_ESTABLISHED:
7551                 return (TS_DATA_XFER);
7552         case TCPS_CLOSE_WAIT:
7553                 return (TS_WREQ_ORDREL);
7554         case TCPS_FIN_WAIT_1:
7555                 return (TS_WIND_ORDREL);
7556         case TCPS_FIN_WAIT_2:
7557                 return (TS_WIND_ORDREL);
7558 
7559         case TCPS_CLOSING:
7560         case TCPS_LAST_ACK:
7561         case TCPS_TIME_WAIT:
7562         case TCPS_CLOSED:
7563                 /*
7564                  * Following TS_WACK_DREQ7 is a rendition of "not
7565                  * yet TS_IDLE" TPI state. There is no best match to any
7566                  * TPI state for TCPS_{CLOSING, LAST_ACK, TIME_WAIT} but we
7567                  * choose a value chosen that will map to TLI/XTI level
7568                  * state of TSTATECHNG (state is process of changing) which
7569                  * captures what this dummy state represents.
7570                  */
7571                 return (TS_WACK_DREQ7);
7572         default:
7573                 cmn_err(CE_WARN, "tcp_tpistate: strange state (%d) %s",
7574                     tcp->tcp_state, tcp_display(tcp, NULL,
7575                     DISP_PORT_ONLY));
7576                 return (TS_UNBND);
7577         }
7578 }
7579 
7580 static void
7581 tcp_copy_info(struct T_info_ack *tia, tcp_t *tcp)
7582 {
7583         tcp_stack_t     *tcps = tcp->tcp_tcps;
7584 
7585         if (tcp->tcp_family == AF_INET6)
7586                 *tia = tcp_g_t_info_ack_v6;
7587         else
7588                 *tia = tcp_g_t_info_ack;
7589         tia->CURRENT_state = tcp_tpistate(tcp);
7590         tia->OPT_size = tcp_max_optsize;
7591         if (tcp->tcp_mss == 0) {
7592                 /* Not yet set - tcp_open does not set mss */
7593                 if (tcp->tcp_ipversion == IPV4_VERSION)
7594                         tia->TIDU_size = tcps->tcps_mss_def_ipv4;
7595                 else
7596                         tia->TIDU_size = tcps->tcps_mss_def_ipv6;
7597         } else {
7598                 tia->TIDU_size = tcp->tcp_mss;
7599         }
7600         /* TODO: Default ETSDU is 1.  Is that correct for tcp? */
7601 }
7602 
7603 /*
7604  * This routine responds to T_CAPABILITY_REQ messages.  It is called by
7605  * tcp_wput.  Much of the T_CAPABILITY_ACK information is copied from
7606  * tcp_g_t_info_ack.  The current state of the stream is copied from
7607  * tcp_state.
7608  */
7609 static void
7610 tcp_capability_req(tcp_t *tcp, mblk_t *mp)
7611 {
7612         t_uscalar_t             cap_bits1;
7613         struct T_capability_ack *tcap;
7614 
7615         if (MBLKL(mp) < sizeof (struct T_capability_req)) {
7616                 freemsg(mp);
7617                 return;
7618         }
7619 
7620         cap_bits1 = ((struct T_capability_req *)mp->b_rptr)->CAP_bits1;
7621 
7622         mp = tpi_ack_alloc(mp, sizeof (struct T_capability_ack),
7623             mp->b_datap->db_type, T_CAPABILITY_ACK);
7624         if (mp == NULL)
7625                 return;
7626 
7627         tcap = (struct T_capability_ack *)mp->b_rptr;
7628         tcap->CAP_bits1 = 0;
7629 
7630         if (cap_bits1 & TC1_INFO) {
7631                 tcp_copy_info(&tcap->INFO_ack, tcp);
7632                 tcap->CAP_bits1 |= TC1_INFO;
7633         }
7634 
7635         if (cap_bits1 & TC1_ACCEPTOR_ID) {
7636                 tcap->ACCEPTOR_id = tcp->tcp_acceptor_id;
7637                 tcap->CAP_bits1 |= TC1_ACCEPTOR_ID;
7638         }
7639 
7640         putnext(tcp->tcp_rq, mp);
7641 }
7642 
7643 /*
7644  * This routine responds to T_INFO_REQ messages.  It is called by tcp_wput.
7645  * Most of the T_INFO_ACK information is copied from tcp_g_t_info_ack.
7646  * The current state of the stream is copied from tcp_state.
7647  */
7648 static void
7649 tcp_info_req(tcp_t *tcp, mblk_t *mp)
7650 {
7651         mp = tpi_ack_alloc(mp, sizeof (struct T_info_ack), M_PCPROTO,
7652             T_INFO_ACK);
7653         if (!mp) {
7654                 tcp_err_ack(tcp, mp, TSYSERR, ENOMEM);
7655                 return;
7656         }
7657         tcp_copy_info((struct T_info_ack *)mp->b_rptr, tcp);
7658         putnext(tcp->tcp_rq, mp);
7659 }
7660 
7661 /* Respond to the TPI addr request */
7662 static void
7663 tcp_addr_req(tcp_t *tcp, mblk_t *mp)
7664 {
7665         sin_t   *sin;
7666         mblk_t  *ackmp;
7667         struct T_addr_ack *taa;
7668 
7669         /* Make it large enough for worst case */
7670         ackmp = reallocb(mp, sizeof (struct T_addr_ack) +
7671             2 * sizeof (sin6_t), 1);
7672         if (ackmp == NULL) {
7673                 tcp_err_ack(tcp, mp, TSYSERR, ENOMEM);
7674                 return;
7675         }
7676 
7677         if (tcp->tcp_ipversion == IPV6_VERSION) {
7678                 tcp_addr_req_ipv6(tcp, ackmp);
7679                 return;
7680         }
7681         taa = (struct T_addr_ack *)ackmp->b_rptr;
7682 
7683         bzero(taa, sizeof (struct T_addr_ack));
7684         ackmp->b_wptr = (uchar_t *)&taa[1];
7685 
7686         taa->PRIM_type = T_ADDR_ACK;
7687         ackmp->b_datap->db_type = M_PCPROTO;
7688 
7689         /*
7690          * Note: Following code assumes 32 bit alignment of basic
7691          * data structures like sin_t and struct T_addr_ack.
7692          */
7693         if (tcp->tcp_state >= TCPS_BOUND) {
7694                 /*
7695                  * Fill in local address
7696                  */
7697                 taa->LOCADDR_length = sizeof (sin_t);
7698                 taa->LOCADDR_offset = sizeof (*taa);
7699 
7700                 sin = (sin_t *)&taa[1];
7701 
7702                 /* Fill zeroes and then intialize non-zero fields */
7703                 *sin = sin_null;
7704 
7705                 sin->sin_family = AF_INET;
7706 
7707                 sin->sin_addr.s_addr = tcp->tcp_ipha->ipha_src;
7708                 sin->sin_port = *(uint16_t *)tcp->tcp_tcph->th_lport;
7709 
7710                 ackmp->b_wptr = (uchar_t *)&sin[1];
7711 
7712                 if (tcp->tcp_state >= TCPS_SYN_RCVD) {
7713                         /*
7714                          * Fill in Remote address
7715                          */
7716                         taa->REMADDR_length = sizeof (sin_t);
7717                         taa->REMADDR_offset = ROUNDUP32(taa->LOCADDR_offset +
7718                             taa->LOCADDR_length);
7719 
7720                         sin = (sin_t *)(ackmp->b_rptr + taa->REMADDR_offset);
7721                         *sin = sin_null;
7722                         sin->sin_family = AF_INET;
7723                         sin->sin_addr.s_addr = tcp->tcp_remote;
7724                         sin->sin_port = tcp->tcp_fport;
7725 
7726                         ackmp->b_wptr = (uchar_t *)&sin[1];
7727                 }
7728         }
7729         putnext(tcp->tcp_rq, ackmp);
7730 }
7731 
7732 /* Assumes that tcp_addr_req gets enough space and alignment */
7733 static void
7734 tcp_addr_req_ipv6(tcp_t *tcp, mblk_t *ackmp)
7735 {
7736         sin6_t  *sin6;
7737         struct T_addr_ack *taa;
7738 
7739         ASSERT(tcp->tcp_ipversion == IPV6_VERSION);
7740         ASSERT(OK_32PTR(ackmp->b_rptr));
7741         ASSERT(ackmp->b_wptr - ackmp->b_rptr >= sizeof (struct T_addr_ack) +
7742             2 * sizeof (sin6_t));
7743 
7744         taa = (struct T_addr_ack *)ackmp->b_rptr;
7745 
7746         bzero(taa, sizeof (struct T_addr_ack));
7747         ackmp->b_wptr = (uchar_t *)&taa[1];
7748 
7749         taa->PRIM_type = T_ADDR_ACK;
7750         ackmp->b_datap->db_type = M_PCPROTO;
7751 
7752         /*
7753          * Note: Following code assumes 32 bit alignment of basic
7754          * data structures like sin6_t and struct T_addr_ack.
7755          */
7756         if (tcp->tcp_state >= TCPS_BOUND) {
7757                 /*
7758                  * Fill in local address
7759                  */
7760                 taa->LOCADDR_length = sizeof (sin6_t);
7761                 taa->LOCADDR_offset = sizeof (*taa);
7762 
7763                 sin6 = (sin6_t *)&taa[1];
7764                 *sin6 = sin6_null;
7765 
7766                 sin6->sin6_family = AF_INET6;
7767                 sin6->sin6_addr = tcp->tcp_ip6h->ip6_src;
7768                 sin6->sin6_port = tcp->tcp_lport;
7769 
7770                 ackmp->b_wptr = (uchar_t *)&sin6[1];
7771 
7772                 if (tcp->tcp_state >= TCPS_SYN_RCVD) {
7773                         /*
7774                          * Fill in Remote address
7775                          */
7776                         taa->REMADDR_length = sizeof (sin6_t);
7777                         taa->REMADDR_offset = ROUNDUP32(taa->LOCADDR_offset +
7778                             taa->LOCADDR_length);
7779 
7780                         sin6 = (sin6_t *)(ackmp->b_rptr + taa->REMADDR_offset);
7781                         *sin6 = sin6_null;
7782                         sin6->sin6_family = AF_INET6;
7783                         sin6->sin6_flowinfo =
7784                             tcp->tcp_ip6h->ip6_vcf &
7785                             ~IPV6_VERS_AND_FLOW_MASK;
7786                         sin6->sin6_addr = tcp->tcp_remote_v6;
7787                         sin6->sin6_port = tcp->tcp_fport;
7788 
7789                         ackmp->b_wptr = (uchar_t *)&sin6[1];
7790                 }
7791         }
7792         putnext(tcp->tcp_rq, ackmp);
7793 }
7794 
7795 /*
7796  * Handle reinitialization of a tcp structure.
7797  * Maintain "binding state" resetting the state to BOUND, LISTEN, or IDLE.
7798  */
7799 static void
7800 tcp_reinit(tcp_t *tcp)
7801 {
7802         mblk_t  *mp;
7803         int     err;
7804         tcp_stack_t     *tcps = tcp->tcp_tcps;
7805 
7806         TCP_STAT(tcps, tcp_reinit_calls);
7807 
7808         /* tcp_reinit should never be called for detached tcp_t's */
7809         ASSERT(tcp->tcp_listener == NULL);
7810         ASSERT((tcp->tcp_family == AF_INET &&
7811             tcp->tcp_ipversion == IPV4_VERSION) ||
7812             (tcp->tcp_family == AF_INET6 &&
7813             (tcp->tcp_ipversion == IPV4_VERSION ||
7814             tcp->tcp_ipversion == IPV6_VERSION)));
7815 
7816         /* Cancel outstanding timers */
7817         tcp_timers_stop(tcp);
7818 
7819         /*
7820          * Reset everything in the state vector, after updating global
7821          * MIB data from instance counters.
7822          */
7823         UPDATE_MIB(&tcps->tcps_mib, tcpHCInSegs, tcp->tcp_ibsegs);
7824         tcp->tcp_ibsegs = 0;
7825         UPDATE_MIB(&tcps->tcps_mib, tcpHCOutSegs, tcp->tcp_obsegs);
7826         tcp->tcp_obsegs = 0;
7827 
7828         tcp_close_mpp(&tcp->tcp_xmit_head);
7829         if (tcp->tcp_snd_zcopy_aware)
7830                 tcp_zcopy_notify(tcp);
7831         tcp->tcp_xmit_last = tcp->tcp_xmit_tail = NULL;
7832         tcp->tcp_unsent = tcp->tcp_xmit_tail_unsent = 0;
7833         mutex_enter(&tcp->tcp_non_sq_lock);
7834         if (tcp->tcp_flow_stopped &&
7835             TCP_UNSENT_BYTES(tcp) <= tcp->tcp_xmit_lowater) {
7836                 tcp_clrqfull(tcp);
7837         }
7838         mutex_exit(&tcp->tcp_non_sq_lock);
7839         tcp_close_mpp(&tcp->tcp_reass_head);
7840         tcp->tcp_reass_tail = NULL;
7841         if (tcp->tcp_rcv_list != NULL) {
7842                 /* Free b_next chain */
7843                 tcp_close_mpp(&tcp->tcp_rcv_list);
7844                 tcp->tcp_rcv_last_head = NULL;
7845                 tcp->tcp_rcv_last_tail = NULL;
7846                 tcp->tcp_rcv_cnt = 0;
7847         }
7848         tcp->tcp_rcv_last_tail = NULL;
7849 
7850         if ((mp = tcp->tcp_urp_mp) != NULL) {
7851                 freemsg(mp);
7852                 tcp->tcp_urp_mp = NULL;
7853         }
7854         if ((mp = tcp->tcp_urp_mark_mp) != NULL) {
7855                 freemsg(mp);
7856                 tcp->tcp_urp_mark_mp = NULL;
7857         }
7858         if (tcp->tcp_fused_sigurg_mp != NULL) {
7859                 freeb(tcp->tcp_fused_sigurg_mp);
7860                 tcp->tcp_fused_sigurg_mp = NULL;
7861         }
7862 
7863         /*
7864          * Following is a union with two members which are
7865          * identical types and size so the following cleanup
7866          * is enough.
7867          */
7868         tcp_close_mpp(&tcp->tcp_conn.tcp_eager_conn_ind);
7869 
7870         CL_INET_DISCONNECT(tcp);
7871 
7872         /*
7873          * The connection can't be on the tcp_time_wait_head list
7874          * since it is not detached.
7875          */
7876         ASSERT(tcp->tcp_time_wait_next == NULL);
7877         ASSERT(tcp->tcp_time_wait_prev == NULL);
7878         ASSERT(tcp->tcp_time_wait_expire == 0);
7879 
7880         if (tcp->tcp_kssl_pending) {
7881                 tcp->tcp_kssl_pending = B_FALSE;
7882 
7883                 /* Don't reset if the initialized by bind. */
7884                 if (tcp->tcp_kssl_ent != NULL) {
7885                         kssl_release_ent(tcp->tcp_kssl_ent, NULL,
7886                             KSSL_NO_PROXY);
7887                 }
7888         }
7889         if (tcp->tcp_kssl_ctx != NULL) {
7890                 kssl_release_ctx(tcp->tcp_kssl_ctx);
7891                 tcp->tcp_kssl_ctx = NULL;
7892         }
7893 
7894         /*
7895          * Reset/preserve other values
7896          */
7897         tcp_reinit_values(tcp);
7898         ipcl_hash_remove(tcp->tcp_connp);
7899         conn_delete_ire(tcp->tcp_connp, NULL);
7900         tcp_ipsec_cleanup(tcp);
7901 
7902         if (tcp->tcp_conn_req_max != 0) {
7903                 /*
7904                  * This is the case when a TLI program uses the same
7905                  * transport end point to accept a connection.  This
7906                  * makes the TCP both a listener and acceptor.  When
7907                  * this connection is closed, we need to set the state
7908                  * back to TCPS_LISTEN.  Make sure that the eager list
7909                  * is reinitialized.
7910                  *
7911                  * Note that this stream is still bound to the four
7912                  * tuples of the previous connection in IP.  If a new
7913                  * SYN with different foreign address comes in, IP will
7914                  * not find it and will send it to the global queue.  In
7915                  * the global queue, TCP will do a tcp_lookup_listener()
7916                  * to find this stream.  This works because this stream
7917                  * is only removed from connected hash.
7918                  *
7919                  */
7920                 tcp->tcp_state = TCPS_LISTEN;
7921                 tcp->tcp_eager_next_q0 = tcp->tcp_eager_prev_q0 = tcp;
7922                 tcp->tcp_eager_next_drop_q0 = tcp;
7923                 tcp->tcp_eager_prev_drop_q0 = tcp;
7924                 tcp->tcp_connp->conn_recv = tcp_conn_request;
7925                 if (tcp->tcp_family == AF_INET6) {
7926                         ASSERT(tcp->tcp_connp->conn_af_isv6);
7927                         (void) ipcl_bind_insert_v6(tcp->tcp_connp, IPPROTO_TCP,
7928                             &tcp->tcp_ip6h->ip6_src, tcp->tcp_lport);
7929                 } else {
7930                         ASSERT(!tcp->tcp_connp->conn_af_isv6);
7931                         (void) ipcl_bind_insert(tcp->tcp_connp, IPPROTO_TCP,
7932                             tcp->tcp_ipha->ipha_src, tcp->tcp_lport);
7933                 }
7934         } else {
7935                 tcp->tcp_state = TCPS_BOUND;
7936         }
7937 
7938         /*
7939          * Initialize to default values
7940          * Can't fail since enough header template space already allocated
7941          * at open().
7942          */
7943         err = tcp_init_values(tcp);
7944         ASSERT(err == 0);
7945         /* Restore state in tcp_tcph */
7946         bcopy(&tcp->tcp_lport, tcp->tcp_tcph->th_lport, TCP_PORT_LEN);
7947         if (tcp->tcp_ipversion == IPV4_VERSION)
7948                 tcp->tcp_ipha->ipha_src = tcp->tcp_bound_source;
7949         else
7950                 tcp->tcp_ip6h->ip6_src = tcp->tcp_bound_source_v6;
7951         /*
7952          * Copy of the src addr. in tcp_t is needed in tcp_t
7953          * since the lookup funcs can only lookup on tcp_t
7954          */
7955         tcp->tcp_ip_src_v6 = tcp->tcp_bound_source_v6;
7956 
7957         ASSERT(tcp->tcp_ptpbhn != NULL);
7958         tcp->tcp_rq->q_hiwat = tcps->tcps_recv_hiwat;
7959         tcp->tcp_rwnd = tcps->tcps_recv_hiwat;
7960         tcp->tcp_mss = tcp->tcp_ipversion != IPV4_VERSION ?
7961             tcps->tcps_mss_def_ipv6 : tcps->tcps_mss_def_ipv4;
7962 }
7963 
7964 /*
7965  * Force values to zero that need be zero.
7966  * Do not touch values asociated with the BOUND or LISTEN state
7967  * since the connection will end up in that state after the reinit.
7968  * NOTE: tcp_reinit_values MUST have a line for each field in the tcp_t
7969  * structure!
7970  */
7971 static void
7972 tcp_reinit_values(tcp)
7973         tcp_t *tcp;
7974 {
7975         tcp_stack_t     *tcps = tcp->tcp_tcps;
7976 
7977 #ifndef lint
7978 #define DONTCARE(x)
7979 #define PRESERVE(x)
7980 #else
7981 #define DONTCARE(x)     ((x) = (x))
7982 #define PRESERVE(x)     ((x) = (x))
7983 #endif  /* lint */
7984 
7985         PRESERVE(tcp->tcp_bind_hash);
7986         PRESERVE(tcp->tcp_ptpbhn);
7987         PRESERVE(tcp->tcp_acceptor_hash);
7988         PRESERVE(tcp->tcp_ptpahn);
7989 
7990         /* Should be ASSERT NULL on these with new code! */
7991         ASSERT(tcp->tcp_time_wait_next == NULL);
7992         ASSERT(tcp->tcp_time_wait_prev == NULL);
7993         ASSERT(tcp->tcp_time_wait_expire == 0);
7994         PRESERVE(tcp->tcp_state);
7995         PRESERVE(tcp->tcp_rq);
7996         PRESERVE(tcp->tcp_wq);
7997 
7998         ASSERT(tcp->tcp_xmit_head == NULL);
7999         ASSERT(tcp->tcp_xmit_last == NULL);
8000         ASSERT(tcp->tcp_unsent == 0);
8001         ASSERT(tcp->tcp_xmit_tail == NULL);
8002         ASSERT(tcp->tcp_xmit_tail_unsent == 0);
8003 
8004         tcp->tcp_snxt = 0;                   /* Displayed in mib */
8005         tcp->tcp_suna = 0;                   /* Displayed in mib */
8006         tcp->tcp_swnd = 0;
8007         DONTCARE(tcp->tcp_cwnd);             /* Init in tcp_mss_set */
8008 
8009         ASSERT(tcp->tcp_ibsegs == 0);
8010         ASSERT(tcp->tcp_obsegs == 0);
8011 
8012         if (tcp->tcp_iphc != NULL) {
8013                 ASSERT(tcp->tcp_iphc_len >= TCP_MAX_COMBINED_HEADER_LENGTH);
8014                 bzero(tcp->tcp_iphc, tcp->tcp_iphc_len);
8015         }
8016 
8017         DONTCARE(tcp->tcp_naglim);           /* Init in tcp_init_values */
8018         DONTCARE(tcp->tcp_hdr_len);          /* Init in tcp_init_values */
8019         DONTCARE(tcp->tcp_ipha);
8020         DONTCARE(tcp->tcp_ip6h);
8021         DONTCARE(tcp->tcp_ip_hdr_len);
8022         DONTCARE(tcp->tcp_tcph);
8023         DONTCARE(tcp->tcp_tcp_hdr_len);              /* Init in tcp_init_values */
8024         tcp->tcp_valid_bits = 0;
8025 
8026         DONTCARE(tcp->tcp_xmit_hiwater);     /* Init in tcp_init_values */
8027         DONTCARE(tcp->tcp_timer_backoff);    /* Init in tcp_init_values */
8028         DONTCARE(tcp->tcp_last_recv_time);   /* Init in tcp_init_values */
8029         tcp->tcp_last_rcv_lbolt = 0;
8030 
8031         tcp->tcp_init_cwnd = 0;
8032 
8033         tcp->tcp_urp_last_valid = 0;
8034         tcp->tcp_hard_binding = 0;
8035         tcp->tcp_hard_bound = 0;
8036         PRESERVE(tcp->tcp_cred);
8037         PRESERVE(tcp->tcp_cpid);
8038         PRESERVE(tcp->tcp_open_time);
8039         PRESERVE(tcp->tcp_exclbind);
8040 
8041         tcp->tcp_fin_acked = 0;
8042         tcp->tcp_fin_rcvd = 0;
8043         tcp->tcp_fin_sent = 0;
8044         tcp->tcp_ordrel_done = 0;
8045 
8046         tcp->tcp_debug = 0;
8047         tcp->tcp_dontroute = 0;
8048         tcp->tcp_broadcast = 0;
8049 
8050         tcp->tcp_useloopback = 0;
8051         tcp->tcp_reuseaddr = 0;
8052         tcp->tcp_oobinline = 0;
8053         tcp->tcp_dgram_errind = 0;
8054 
8055         tcp->tcp_detached = 0;
8056         tcp->tcp_bind_pending = 0;
8057         tcp->tcp_unbind_pending = 0;
8058         tcp->tcp_deferred_clean_death = 0;
8059 
8060         tcp->tcp_snd_ws_ok = B_FALSE;
8061         tcp->tcp_snd_ts_ok = B_FALSE;
8062         tcp->tcp_linger = 0;
8063         tcp->tcp_ka_enabled = 0;
8064         tcp->tcp_zero_win_probe = 0;
8065 
8066         tcp->tcp_loopback = 0;
8067         tcp->tcp_localnet = 0;
8068         tcp->tcp_syn_defense = 0;
8069         tcp->tcp_set_timer = 0;
8070 
8071         tcp->tcp_active_open = 0;
8072         ASSERT(tcp->tcp_timeout == B_FALSE);
8073         tcp->tcp_rexmit = B_FALSE;
8074         tcp->tcp_xmit_zc_clean = B_FALSE;
8075 
8076         tcp->tcp_snd_sack_ok = B_FALSE;
8077         PRESERVE(tcp->tcp_recvdstaddr);
8078         tcp->tcp_hwcksum = B_FALSE;
8079 
8080         tcp->tcp_ire_ill_check_done = B_FALSE;
8081         DONTCARE(tcp->tcp_maxpsz);           /* Init in tcp_init_values */
8082 
8083         tcp->tcp_mdt = B_FALSE;
8084         tcp->tcp_mdt_hdr_head = 0;
8085         tcp->tcp_mdt_hdr_tail = 0;
8086 
8087         tcp->tcp_conn_def_q0 = 0;
8088         tcp->tcp_ip_forward_progress = B_FALSE;
8089         tcp->tcp_anon_priv_bind = 0;
8090         tcp->tcp_ecn_ok = B_FALSE;
8091 
8092         tcp->tcp_cwr = B_FALSE;
8093         tcp->tcp_ecn_echo_on = B_FALSE;
8094 
8095         if (tcp->tcp_sack_info != NULL) {
8096                 if (tcp->tcp_notsack_list != NULL) {
8097                         TCP_NOTSACK_REMOVE_ALL(tcp->tcp_notsack_list);
8098                 }
8099                 kmem_cache_free(tcp_sack_info_cache, tcp->tcp_sack_info);
8100                 tcp->tcp_sack_info = NULL;
8101         }
8102 
8103         tcp->tcp_rcv_ws = 0;
8104         tcp->tcp_snd_ws = 0;
8105         tcp->tcp_ts_recent = 0;
8106         tcp->tcp_rnxt = 0;                   /* Displayed in mib */
8107         DONTCARE(tcp->tcp_rwnd);             /* Set in tcp_reinit() */
8108         tcp->tcp_if_mtu = 0;
8109 
8110         ASSERT(tcp->tcp_reass_head == NULL);
8111         ASSERT(tcp->tcp_reass_tail == NULL);
8112 
8113         tcp->tcp_cwnd_cnt = 0;
8114 
8115         ASSERT(tcp->tcp_rcv_list == NULL);
8116         ASSERT(tcp->tcp_rcv_last_head == NULL);
8117         ASSERT(tcp->tcp_rcv_last_tail == NULL);
8118         ASSERT(tcp->tcp_rcv_cnt == 0);
8119 
8120         DONTCARE(tcp->tcp_cwnd_ssthresh);    /* Init in tcp_adapt_ire */
8121         DONTCARE(tcp->tcp_cwnd_max);         /* Init in tcp_init_values */
8122         tcp->tcp_csuna = 0;
8123 
8124         tcp->tcp_rto = 0;                    /* Displayed in MIB */
8125         DONTCARE(tcp->tcp_rtt_sa);           /* Init in tcp_init_values */
8126         DONTCARE(tcp->tcp_rtt_sd);           /* Init in tcp_init_values */
8127         tcp->tcp_rtt_update = 0;
8128 
8129         DONTCARE(tcp->tcp_swl1); /* Init in case TCPS_LISTEN/TCPS_SYN_SENT */
8130         DONTCARE(tcp->tcp_swl2); /* Init in case TCPS_LISTEN/TCPS_SYN_SENT */
8131 
8132         tcp->tcp_rack = 0;                   /* Displayed in mib */
8133         tcp->tcp_rack_cnt = 0;
8134         tcp->tcp_rack_cur_max = 0;
8135         tcp->tcp_rack_abs_max = 0;
8136 
8137         tcp->tcp_max_swnd = 0;
8138 
8139         ASSERT(tcp->tcp_listener == NULL);
8140 
8141         DONTCARE(tcp->tcp_xmit_lowater);     /* Init in tcp_init_values */
8142 
8143         DONTCARE(tcp->tcp_irs);                      /* tcp_valid_bits cleared */
8144         DONTCARE(tcp->tcp_iss);                      /* tcp_valid_bits cleared */
8145         DONTCARE(tcp->tcp_fss);                      /* tcp_valid_bits cleared */
8146         DONTCARE(tcp->tcp_urg);                      /* tcp_valid_bits cleared */
8147 
8148         ASSERT(tcp->tcp_conn_req_cnt_q == 0);
8149         ASSERT(tcp->tcp_conn_req_cnt_q0 == 0);
8150         PRESERVE(tcp->tcp_conn_req_max);
8151         PRESERVE(tcp->tcp_conn_req_seqnum);
8152 
8153         DONTCARE(tcp->tcp_ip_hdr_len);               /* Init in tcp_init_values */
8154         DONTCARE(tcp->tcp_first_timer_threshold); /* Init in tcp_init_values */
8155         DONTCARE(tcp->tcp_second_timer_threshold); /* Init in tcp_init_values */
8156         DONTCARE(tcp->tcp_first_ctimer_threshold); /* Init in tcp_init_values */
8157         DONTCARE(tcp->tcp_second_ctimer_threshold); /* in tcp_init_values */
8158 
8159         tcp->tcp_lingertime = 0;
8160 
8161         DONTCARE(tcp->tcp_urp_last); /* tcp_urp_last_valid is cleared */
8162         ASSERT(tcp->tcp_urp_mp == NULL);
8163         ASSERT(tcp->tcp_urp_mark_mp == NULL);
8164         ASSERT(tcp->tcp_fused_sigurg_mp == NULL);
8165 
8166         ASSERT(tcp->tcp_eager_next_q == NULL);
8167         ASSERT(tcp->tcp_eager_last_q == NULL);
8168         ASSERT((tcp->tcp_eager_next_q0 == NULL &&
8169             tcp->tcp_eager_prev_q0 == NULL) ||
8170             tcp->tcp_eager_next_q0 == tcp->tcp_eager_prev_q0);
8171         ASSERT(tcp->tcp_conn.tcp_eager_conn_ind == NULL);
8172 
8173         ASSERT((tcp->tcp_eager_next_drop_q0 == NULL &&
8174             tcp->tcp_eager_prev_drop_q0 == NULL) ||
8175             tcp->tcp_eager_next_drop_q0 == tcp->tcp_eager_prev_drop_q0);
8176 
8177         tcp->tcp_client_errno = 0;
8178 
8179         DONTCARE(tcp->tcp_sum);                      /* Init in tcp_init_values */
8180 
8181         tcp->tcp_remote_v6 = ipv6_all_zeros; /* Displayed in MIB */
8182 
8183         PRESERVE(tcp->tcp_bound_source_v6);
8184         tcp->tcp_last_sent_len = 0;
8185         tcp->tcp_dupack_cnt = 0;
8186 
8187         tcp->tcp_fport = 0;                  /* Displayed in MIB */
8188         PRESERVE(tcp->tcp_lport);
8189 
8190         PRESERVE(tcp->tcp_acceptor_lockp);
8191 
8192         ASSERT(tcp->tcp_ordrelid == 0);
8193         PRESERVE(tcp->tcp_acceptor_id);
8194         DONTCARE(tcp->tcp_ipsec_overhead);
8195 
8196         /*
8197          * If tcp_tracing flag is ON (i.e. We have a trace buffer
8198          * in tcp structure and now tracing), Re-initialize all
8199          * members of tcp_traceinfo.
8200          */
8201         if (tcp->tcp_tracebuf != NULL) {
8202                 bzero(tcp->tcp_tracebuf, sizeof (tcptrch_t));
8203         }
8204 
8205         PRESERVE(tcp->tcp_family);
8206         if (tcp->tcp_family == AF_INET6) {
8207                 tcp->tcp_ipversion = IPV6_VERSION;
8208                 tcp->tcp_mss = tcps->tcps_mss_def_ipv6;
8209         } else {
8210                 tcp->tcp_ipversion = IPV4_VERSION;
8211                 tcp->tcp_mss = tcps->tcps_mss_def_ipv4;
8212         }
8213 
8214         tcp->tcp_bound_if = 0;
8215         tcp->tcp_ipv6_recvancillary = 0;
8216         tcp->tcp_recvifindex = 0;
8217         tcp->tcp_recvhops = 0;
8218         tcp->tcp_closed = 0;
8219         tcp->tcp_cleandeathtag = 0;
8220         if (tcp->tcp_hopopts != NULL) {
8221                 mi_free(tcp->tcp_hopopts);
8222                 tcp->tcp_hopopts = NULL;
8223                 tcp->tcp_hopoptslen = 0;
8224         }
8225         ASSERT(tcp->tcp_hopoptslen == 0);
8226         if (tcp->tcp_dstopts != NULL) {
8227                 mi_free(tcp->tcp_dstopts);
8228                 tcp->tcp_dstopts = NULL;
8229                 tcp->tcp_dstoptslen = 0;
8230         }
8231         ASSERT(tcp->tcp_dstoptslen == 0);
8232         if (tcp->tcp_rtdstopts != NULL) {
8233                 mi_free(tcp->tcp_rtdstopts);
8234                 tcp->tcp_rtdstopts = NULL;
8235                 tcp->tcp_rtdstoptslen = 0;
8236         }
8237         ASSERT(tcp->tcp_rtdstoptslen == 0);
8238         if (tcp->tcp_rthdr != NULL) {
8239                 mi_free(tcp->tcp_rthdr);
8240                 tcp->tcp_rthdr = NULL;
8241                 tcp->tcp_rthdrlen = 0;
8242         }
8243         ASSERT(tcp->tcp_rthdrlen == 0);
8244         PRESERVE(tcp->tcp_drop_opt_ack_cnt);
8245 
8246         /* Reset fusion-related fields */
8247         tcp->tcp_fused = B_FALSE;
8248         tcp->tcp_unfusable = B_FALSE;
8249         tcp->tcp_fused_sigurg = B_FALSE;
8250         tcp->tcp_direct_sockfs = B_FALSE;
8251         tcp->tcp_fuse_syncstr_stopped = B_FALSE;
8252         tcp->tcp_fuse_syncstr_plugged = B_FALSE;
8253         tcp->tcp_loopback_peer = NULL;
8254         tcp->tcp_fuse_rcv_hiwater = 0;
8255         tcp->tcp_fuse_rcv_unread_hiwater = 0;
8256         tcp->tcp_fuse_rcv_unread_cnt = 0;
8257 
8258         tcp->tcp_lso = B_FALSE;
8259 
8260         tcp->tcp_in_ack_unsent = 0;
8261         tcp->tcp_cork = B_FALSE;
8262         tcp->tcp_tconnind_started = B_FALSE;
8263 
8264         PRESERVE(tcp->tcp_squeue_bytes);
8265 
8266         ASSERT(tcp->tcp_kssl_ctx == NULL);
8267         ASSERT(!tcp->tcp_kssl_pending);
8268         PRESERVE(tcp->tcp_kssl_ent);
8269 
8270         /* Sodirect */
8271         tcp->tcp_sodirect = NULL;
8272 
8273         tcp->tcp_closemp_used = B_FALSE;
8274 
8275 #ifdef DEBUG
8276         DONTCARE(tcp->tcmp_stk[0]);
8277 #endif
8278 
8279 
8280 #undef  DONTCARE
8281 #undef  PRESERVE
8282 }
8283 
8284 /*
8285  * Allocate necessary resources and initialize state vector.
8286  * Guaranteed not to fail so that when an error is returned,
8287  * the caller doesn't need to do any additional cleanup.
8288  */
8289 int
8290 tcp_init(tcp_t *tcp, queue_t *q)
8291 {
8292         int     err;
8293 
8294         tcp->tcp_rq = q;
8295         tcp->tcp_wq = WR(q);
8296         tcp->tcp_state = TCPS_IDLE;
8297         if ((err = tcp_init_values(tcp)) != 0)
8298                 tcp_timers_stop(tcp);
8299         return (err);
8300 }
8301 
8302 static int
8303 tcp_init_values(tcp_t *tcp)
8304 {
8305         int     err;
8306         tcp_stack_t     *tcps = tcp->tcp_tcps;
8307 
8308         ASSERT((tcp->tcp_family == AF_INET &&
8309             tcp->tcp_ipversion == IPV4_VERSION) ||
8310             (tcp->tcp_family == AF_INET6 &&
8311             (tcp->tcp_ipversion == IPV4_VERSION ||
8312             tcp->tcp_ipversion == IPV6_VERSION)));
8313 
8314         /*
8315          * Initialize tcp_rtt_sa and tcp_rtt_sd so that the calculated RTO
8316          * will be close to tcp_rexmit_interval_initial.  By doing this, we
8317          * allow the algorithm to adjust slowly to large fluctuations of RTT
8318          * during first few transmissions of a connection as seen in slow
8319          * links.
8320          */
8321         tcp->tcp_rtt_sa = tcps->tcps_rexmit_interval_initial << 2;
8322         tcp->tcp_rtt_sd = tcps->tcps_rexmit_interval_initial >> 1;
8323         tcp->tcp_rto = (tcp->tcp_rtt_sa >> 3) + tcp->tcp_rtt_sd +
8324             tcps->tcps_rexmit_interval_extra + (tcp->tcp_rtt_sa >> 5) +
8325             tcps->tcps_conn_grace_period;
8326         if (tcp->tcp_rto < tcps->tcps_rexmit_interval_min)
8327                 tcp->tcp_rto = tcps->tcps_rexmit_interval_min;
8328         tcp->tcp_timer_backoff = 0;
8329         tcp->tcp_ms_we_have_waited = 0;
8330         tcp->tcp_last_recv_time = lbolt;
8331         tcp->tcp_cwnd_max = tcps->tcps_cwnd_max_;
8332         tcp->tcp_cwnd_ssthresh = TCP_MAX_LARGEWIN;
8333         tcp->tcp_snd_burst = TCP_CWND_INFINITE;
8334 
8335         tcp->tcp_maxpsz = tcps->tcps_maxpsz_multiplier;
8336 
8337         tcp->tcp_first_timer_threshold = tcps->tcps_ip_notify_interval;
8338         tcp->tcp_first_ctimer_threshold = tcps->tcps_ip_notify_cinterval;
8339         tcp->tcp_second_timer_threshold = tcps->tcps_ip_abort_interval;
8340         /*
8341          * Fix it to tcp_ip_abort_linterval later if it turns out to be a
8342          * passive open.
8343          */
8344         tcp->tcp_second_ctimer_threshold = tcps->tcps_ip_abort_cinterval;
8345 
8346         tcp->tcp_naglim = tcps->tcps_naglim_def;
8347 
8348         /* NOTE:  ISS is now set in tcp_adapt_ire(). */
8349 
8350         tcp->tcp_mdt_hdr_head = 0;
8351         tcp->tcp_mdt_hdr_tail = 0;
8352 
8353         /* Reset fusion-related fields */
8354         tcp->tcp_fused = B_FALSE;
8355         tcp->tcp_unfusable = B_FALSE;
8356         tcp->tcp_fused_sigurg = B_FALSE;
8357         tcp->tcp_direct_sockfs = B_FALSE;
8358         tcp->tcp_fuse_syncstr_stopped = B_FALSE;
8359         tcp->tcp_fuse_syncstr_plugged = B_FALSE;
8360         tcp->tcp_loopback_peer = NULL;
8361         tcp->tcp_fuse_rcv_hiwater = 0;
8362         tcp->tcp_fuse_rcv_unread_hiwater = 0;
8363         tcp->tcp_fuse_rcv_unread_cnt = 0;
8364 
8365         /* Sodirect */
8366         tcp->tcp_sodirect = NULL;
8367 
8368         /* Initialize the header template */
8369         if (tcp->tcp_ipversion == IPV4_VERSION) {
8370                 err = tcp_header_init_ipv4(tcp);
8371         } else {
8372                 err = tcp_header_init_ipv6(tcp);
8373         }
8374         if (err)
8375                 return (err);
8376 
8377         /*
8378          * Init the window scale to the max so tcp_rwnd_set() won't pare
8379          * down tcp_rwnd. tcp_adapt_ire() will set the right value later.
8380          */
8381         tcp->tcp_rcv_ws = TCP_MAX_WINSHIFT;
8382         tcp->tcp_xmit_lowater = tcps->tcps_xmit_lowat;
8383         tcp->tcp_xmit_hiwater = tcps->tcps_xmit_hiwat;
8384 
8385         tcp->tcp_cork = B_FALSE;
8386         /*
8387          * Init the tcp_debug option.  This value determines whether TCP
8388          * calls strlog() to print out debug messages.  Doing this
8389          * initialization here means that this value is not inherited thru
8390          * tcp_reinit().
8391          */
8392         tcp->tcp_debug = tcps->tcps_dbg;
8393 
8394         tcp->tcp_ka_interval = tcps->tcps_keepalive_interval;
8395         tcp->tcp_ka_abort_thres = tcps->tcps_keepalive_abort_interval;
8396 
8397         return (0);
8398 }
8399 
8400 /*
8401  * Initialize the IPv4 header. Loses any record of any IP options.
8402  */
8403 static int
8404 tcp_header_init_ipv4(tcp_t *tcp)
8405 {
8406         tcph_t          *tcph;
8407         uint32_t        sum;
8408         conn_t          *connp;
8409         tcp_stack_t     *tcps = tcp->tcp_tcps;
8410 
8411         /*
8412          * This is a simple initialization. If there's
8413          * already a template, it should never be too small,
8414          * so reuse it.  Otherwise, allocate space for the new one.
8415          */
8416         if (tcp->tcp_iphc == NULL) {
8417                 ASSERT(tcp->tcp_iphc_len == 0);
8418                 tcp->tcp_iphc_len = TCP_MAX_COMBINED_HEADER_LENGTH;
8419                 tcp->tcp_iphc = kmem_cache_alloc(tcp_iphc_cache, KM_NOSLEEP);
8420                 if (tcp->tcp_iphc == NULL) {
8421                         tcp->tcp_iphc_len = 0;
8422                         return (ENOMEM);
8423                 }
8424         }
8425 
8426         /* options are gone; may need a new label */
8427         connp = tcp->tcp_connp;
8428         connp->conn_mlp_type = mlptSingle;
8429         connp->conn_ulp_labeled = !is_system_labeled();
8430         ASSERT(tcp->tcp_iphc_len >= TCP_MAX_COMBINED_HEADER_LENGTH);
8431         tcp->tcp_ipha = (ipha_t *)tcp->tcp_iphc;
8432         tcp->tcp_ip6h = NULL;
8433         tcp->tcp_ipversion = IPV4_VERSION;
8434         tcp->tcp_hdr_len = sizeof (ipha_t) + sizeof (tcph_t);
8435         tcp->tcp_tcp_hdr_len = sizeof (tcph_t);
8436         tcp->tcp_ip_hdr_len = sizeof (ipha_t);
8437         tcp->tcp_ipha->ipha_length = htons(sizeof (ipha_t) + sizeof (tcph_t));
8438         tcp->tcp_ipha->ipha_version_and_hdr_length
8439             = (IP_VERSION << 4) | IP_SIMPLE_HDR_LENGTH_IN_WORDS;
8440         tcp->tcp_ipha->ipha_ident = 0;
8441 
8442         tcp->tcp_ttl = (uchar_t)tcps->tcps_ipv4_ttl;
8443         tcp->tcp_tos = 0;
8444         tcp->tcp_ipha->ipha_fragment_offset_and_flags = 0;
8445         tcp->tcp_ipha->ipha_ttl = (uchar_t)tcps->tcps_ipv4_ttl;
8446         tcp->tcp_ipha->ipha_protocol = IPPROTO_TCP;
8447 
8448         tcph = (tcph_t *)(tcp->tcp_iphc + sizeof (ipha_t));
8449         tcp->tcp_tcph = tcph;
8450         tcph->th_offset_and_rsrvd[0] = (5 << 4);
8451         /*
8452          * IP wants our header length in the checksum field to
8453          * allow it to perform a single pseudo-header+checksum
8454          * calculation on behalf of TCP.
8455          * Include the adjustment for a source route once IP_OPTIONS is set.
8456          */
8457         sum = sizeof (tcph_t) + tcp->tcp_sum;
8458         sum = (sum >> 16) + (sum & 0xFFFF);
8459         U16_TO_ABE16(sum, tcph->th_sum);
8460         return (0);
8461 }
8462 
8463 /*
8464  * Initialize the IPv6 header. Loses any record of any IPv6 extension headers.
8465  */
8466 static int
8467 tcp_header_init_ipv6(tcp_t *tcp)
8468 {
8469         tcph_t  *tcph;
8470         uint32_t        sum;
8471         conn_t  *connp;
8472         tcp_stack_t     *tcps = tcp->tcp_tcps;
8473 
8474         /*
8475          * This is a simple initialization. If there's
8476          * already a template, it should never be too small,
8477          * so reuse it. Otherwise, allocate space for the new one.
8478          * Ensure that there is enough space to "downgrade" the tcp_t
8479          * to an IPv4 tcp_t. This requires having space for a full load
8480          * of IPv4 options, as well as a full load of TCP options
8481          * (TCP_MAX_COMBINED_HEADER_LENGTH, 120 bytes); this is more space
8482          * than a v6 header and a TCP header with a full load of TCP options
8483          * (IPV6_HDR_LEN is 40 bytes; TCP_MAX_HDR_LENGTH is 60 bytes).
8484          * We want to avoid reallocation in the "downgraded" case when
8485          * processing outbound IPv4 options.
8486          */
8487         if (tcp->tcp_iphc == NULL) {
8488                 ASSERT(tcp->tcp_iphc_len == 0);
8489                 tcp->tcp_iphc_len = TCP_MAX_COMBINED_HEADER_LENGTH;
8490                 tcp->tcp_iphc = kmem_cache_alloc(tcp_iphc_cache, KM_NOSLEEP);
8491                 if (tcp->tcp_iphc == NULL) {
8492                         tcp->tcp_iphc_len = 0;
8493                         return (ENOMEM);
8494                 }
8495         }
8496 
8497         /* options are gone; may need a new label */
8498         connp = tcp->tcp_connp;
8499         connp->conn_mlp_type = mlptSingle;
8500         connp->conn_ulp_labeled = !is_system_labeled();
8501 
8502         ASSERT(tcp->tcp_iphc_len >= TCP_MAX_COMBINED_HEADER_LENGTH);
8503         tcp->tcp_ipversion = IPV6_VERSION;
8504         tcp->tcp_hdr_len = IPV6_HDR_LEN + sizeof (tcph_t);
8505         tcp->tcp_tcp_hdr_len = sizeof (tcph_t);
8506         tcp->tcp_ip_hdr_len = IPV6_HDR_LEN;
8507         tcp->tcp_ip6h = (ip6_t *)tcp->tcp_iphc;
8508         tcp->tcp_ipha = NULL;
8509 
8510         /* Initialize the header template */
8511 
8512         tcp->tcp_ip6h->ip6_vcf = IPV6_DEFAULT_VERS_AND_FLOW;
8513         tcp->tcp_ip6h->ip6_plen = ntohs(sizeof (tcph_t));
8514         tcp->tcp_ip6h->ip6_nxt = IPPROTO_TCP;
8515         tcp->tcp_ip6h->ip6_hops = (uint8_t)tcps->tcps_ipv6_hoplimit;
8516 
8517         tcph = (tcph_t *)(tcp->tcp_iphc + IPV6_HDR_LEN);
8518         tcp->tcp_tcph = tcph;
8519         tcph->th_offset_and_rsrvd[0] = (5 << 4);
8520         /*
8521          * IP wants our header length in the checksum field to
8522          * allow it to perform a single psuedo-header+checksum
8523          * calculation on behalf of TCP.
8524          * Include the adjustment for a source route when IPV6_RTHDR is set.
8525          */
8526         sum = sizeof (tcph_t) + tcp->tcp_sum;
8527         sum = (sum >> 16) + (sum & 0xFFFF);
8528         U16_TO_ABE16(sum, tcph->th_sum);
8529         return (0);
8530 }
8531 
8532 /* At minimum we need 8 bytes in the TCP header for the lookup */
8533 #define ICMP_MIN_TCP_HDR        8
8534 
8535 /*
8536  * tcp_icmp_error is called by tcp_rput_other to process ICMP error messages
8537  * passed up by IP. The message is always received on the correct tcp_t.
8538  * Assumes that IP has pulled up everything up to and including the ICMP header.
8539  */
8540 void
8541 tcp_icmp_error(tcp_t *tcp, mblk_t *mp)
8542 {
8543         icmph_t *icmph;
8544         ipha_t  *ipha;
8545         int     iph_hdr_length;
8546         tcph_t  *tcph;
8547         boolean_t ipsec_mctl = B_FALSE;
8548         boolean_t secure;
8549         mblk_t *first_mp = mp;
8550         uint32_t new_mss;
8551         uint32_t ratio;
8552         size_t mp_size = MBLKL(mp);
8553         uint32_t seg_seq;
8554         tcp_stack_t     *tcps = tcp->tcp_tcps;
8555 
8556         /* Assume IP provides aligned packets - otherwise toss */
8557         if (!OK_32PTR(mp->b_rptr)) {
8558                 freemsg(mp);
8559                 return;
8560         }
8561 
8562         /*
8563          * Since ICMP errors are normal data marked with M_CTL when sent
8564          * to TCP or UDP, we have to look for a IPSEC_IN value to identify
8565          * packets starting with an ipsec_info_t, see ipsec_info.h.
8566          */
8567         if ((mp_size == sizeof (ipsec_info_t)) &&
8568             (((ipsec_info_t *)mp->b_rptr)->ipsec_info_type == IPSEC_IN)) {
8569                 ASSERT(mp->b_cont != NULL);
8570                 mp = mp->b_cont;
8571                 /* IP should have done this */
8572                 ASSERT(OK_32PTR(mp->b_rptr));
8573                 mp_size = MBLKL(mp);
8574                 ipsec_mctl = B_TRUE;
8575         }
8576 
8577         /*
8578          * Verify that we have a complete outer IP header. If not, drop it.
8579          */
8580         if (mp_size < sizeof (ipha_t)) {
8581 noticmpv4:
8582                 freemsg(first_mp);
8583                 return;
8584         }
8585 
8586         ipha = (ipha_t *)mp->b_rptr;
8587         /*
8588          * Verify IP version. Anything other than IPv4 or IPv6 packet is sent
8589          * upstream. ICMPv6 is handled in tcp_icmp_error_ipv6.
8590          */
8591         switch (IPH_HDR_VERSION(ipha)) {
8592         case IPV6_VERSION:
8593                 tcp_icmp_error_ipv6(tcp, first_mp, ipsec_mctl);
8594                 return;
8595         case IPV4_VERSION:
8596                 break;
8597         default:
8598                 goto noticmpv4;
8599         }
8600 
8601         /* Skip past the outer IP and ICMP headers */
8602         iph_hdr_length = IPH_HDR_LENGTH(ipha);
8603         icmph = (icmph_t *)&mp->b_rptr[iph_hdr_length];
8604         /*
8605          * If we don't have the correct outer IP header length or if the ULP
8606          * is not IPPROTO_ICMP or if we don't have a complete inner IP header
8607          * send it upstream.
8608          */
8609         if (iph_hdr_length < sizeof (ipha_t) ||
8610             ipha->ipha_protocol != IPPROTO_ICMP ||
8611             (ipha_t *)&icmph[1] + 1 > (ipha_t *)mp->b_wptr) {
8612                 goto noticmpv4;
8613         }
8614         ipha = (ipha_t *)&icmph[1];
8615 
8616         /* Skip past the inner IP and find the ULP header */
8617         iph_hdr_length = IPH_HDR_LENGTH(ipha);
8618         tcph = (tcph_t *)((char *)ipha + iph_hdr_length);
8619         /*
8620          * If we don't have the correct inner IP header length or if the ULP
8621          * is not IPPROTO_TCP or if we don't have at least ICMP_MIN_TCP_HDR
8622          * bytes of TCP header, drop it.
8623          */
8624         if (iph_hdr_length < sizeof (ipha_t) ||
8625             ipha->ipha_protocol != IPPROTO_TCP ||
8626             (uchar_t *)tcph + ICMP_MIN_TCP_HDR > mp->b_wptr) {
8627                 goto noticmpv4;
8628         }
8629 
8630         if (TCP_IS_DETACHED_NONEAGER(tcp)) {
8631                 if (ipsec_mctl) {
8632                         secure = ipsec_in_is_secure(first_mp);
8633                 } else {
8634                         secure = B_FALSE;
8635                 }
8636                 if (secure) {
8637                         /*
8638                          * If we are willing to accept this in clear
8639                          * we don't have to verify policy.
8640                          */
8641                         if (!ipsec_inbound_accept_clear(mp, ipha, NULL)) {
8642                                 if (!tcp_check_policy(tcp, first_mp,
8643                                     ipha, NULL, secure, ipsec_mctl)) {
8644                                         /*
8645                                          * tcp_check_policy called
8646                                          * ip_drop_packet() on failure.
8647                                          */
8648                                         return;
8649                                 }
8650                         }
8651                 }
8652         } else if (ipsec_mctl) {
8653                 /*
8654                  * This is a hard_bound connection. IP has already
8655                  * verified policy. We don't have to do it again.
8656                  */
8657                 freeb(first_mp);
8658                 first_mp = mp;
8659                 ipsec_mctl = B_FALSE;
8660         }
8661 
8662         seg_seq = ABE32_TO_U32(tcph->th_seq);
8663         /*
8664          * TCP SHOULD check that the TCP sequence number contained in
8665          * payload of the ICMP error message is within the range
8666          * SND.UNA <= SEG.SEQ < SND.NXT.
8667          */
8668         if (SEQ_LT(seg_seq, tcp->tcp_suna) || SEQ_GEQ(seg_seq, tcp->tcp_snxt)) {
8669                 /*
8670                  * If the ICMP message is bogus, should we kill the
8671                  * connection, or should we just drop the bogus ICMP
8672                  * message? It would probably make more sense to just
8673                  * drop the message so that if this one managed to get
8674                  * in, the real connection should not suffer.
8675                  */
8676                 goto noticmpv4;
8677         }
8678 
8679         switch (icmph->icmph_type) {
8680         case ICMP_DEST_UNREACHABLE:
8681                 switch (icmph->icmph_code) {
8682                 case ICMP_FRAGMENTATION_NEEDED:
8683                         /*
8684                          * Reduce the MSS based on the new MTU.  This will
8685                          * eliminate any fragmentation locally.
8686                          * N.B.  There may well be some funny side-effects on
8687                          * the local send policy and the remote receive policy.
8688                          * Pending further research, we provide
8689                          * tcp_ignore_path_mtu just in case this proves
8690                          * disastrous somewhere.
8691                          *
8692                          * After updating the MSS, retransmit part of the
8693                          * dropped segment using the new mss by calling
8694                          * tcp_wput_data().  Need to adjust all those
8695                          * params to make sure tcp_wput_data() work properly.
8696                          */
8697                         if (tcps->tcps_ignore_path_mtu)
8698                                 break;
8699 
8700                         /*
8701                          * Decrease the MSS by time stamp options
8702                          * IP options and IPSEC options. tcp_hdr_len
8703                          * includes time stamp option and IP option
8704                          * length.
8705                          */
8706 
8707                         new_mss = ntohs(icmph->icmph_du_mtu) -
8708                             tcp->tcp_hdr_len - tcp->tcp_ipsec_overhead;
8709 
8710                         /*
8711                          * Only update the MSS if the new one is
8712                          * smaller than the previous one.  This is
8713                          * to avoid problems when getting multiple
8714                          * ICMP errors for the same MTU.
8715                          */
8716                         if (new_mss >= tcp->tcp_mss)
8717                                 break;
8718 
8719                         /*
8720                          * Stop doing PMTU if new_mss is less than 68
8721                          * or less than tcp_mss_min.
8722                          * The value 68 comes from rfc 1191.
8723                          */
8724                         if (new_mss < MAX(68, tcps->tcps_mss_min))
8725                                 tcp->tcp_ipha->ipha_fragment_offset_and_flags =
8726                                     0;
8727 
8728                         ratio = tcp->tcp_cwnd / tcp->tcp_mss;
8729                         ASSERT(ratio >= 1);
8730                         tcp_mss_set(tcp, new_mss, B_TRUE);
8731 
8732                         /*
8733                          * Make sure we have something to
8734                          * send.
8735                          */
8736                         if (SEQ_LT(tcp->tcp_suna, tcp->tcp_snxt) &&
8737                             (tcp->tcp_xmit_head != NULL)) {
8738                                 /*
8739                                  * Shrink tcp_cwnd in
8740                                  * proportion to the old MSS/new MSS.
8741                                  */
8742                                 tcp->tcp_cwnd = ratio * tcp->tcp_mss;
8743                                 if ((tcp->tcp_valid_bits & TCP_FSS_VALID) &&
8744                                     (tcp->tcp_unsent == 0)) {
8745                                         tcp->tcp_rexmit_max = tcp->tcp_fss;
8746                                 } else {
8747                                         tcp->tcp_rexmit_max = tcp->tcp_snxt;
8748                                 }
8749                                 tcp->tcp_rexmit_nxt = tcp->tcp_suna;
8750                                 tcp->tcp_rexmit = B_TRUE;
8751                                 tcp->tcp_dupack_cnt = 0;
8752                                 tcp->tcp_snd_burst = TCP_CWND_SS;
8753                                 tcp_ss_rexmit(tcp);
8754                         }
8755                         break;
8756                 case ICMP_PORT_UNREACHABLE:
8757                 case ICMP_PROTOCOL_UNREACHABLE:
8758                         switch (tcp->tcp_state) {
8759                         case TCPS_SYN_SENT:
8760                         case TCPS_SYN_RCVD:
8761                                 /*
8762                                  * ICMP can snipe away incipient
8763                                  * TCP connections as long as
8764                                  * seq number is same as initial
8765                                  * send seq number.
8766                                  */
8767                                 if (seg_seq == tcp->tcp_iss) {
8768                                         (void) tcp_clean_death(tcp,
8769                                             ECONNREFUSED, 6);
8770                                 }
8771                                 break;
8772                         }
8773                         break;
8774                 case ICMP_HOST_UNREACHABLE:
8775                 case ICMP_NET_UNREACHABLE:
8776                         /* Record the error in case we finally time out. */
8777                         if (icmph->icmph_code == ICMP_HOST_UNREACHABLE)
8778                                 tcp->tcp_client_errno = EHOSTUNREACH;
8779                         else
8780                                 tcp->tcp_client_errno = ENETUNREACH;
8781                         if (tcp->tcp_state == TCPS_SYN_RCVD) {
8782                                 if (tcp->tcp_listener != NULL &&
8783                                     tcp->tcp_listener->tcp_syn_defense) {
8784                                         /*
8785                                          * Ditch the half-open connection if we
8786                                          * suspect a SYN attack is under way.
8787                                          */
8788                                         tcp_ip_ire_mark_advice(tcp);
8789                                         (void) tcp_clean_death(tcp,
8790                                             tcp->tcp_client_errno, 7);
8791                                 }
8792                         }
8793                         break;
8794                 default:
8795                         break;
8796                 }
8797                 break;
8798         case ICMP_SOURCE_QUENCH: {
8799                 /*
8800                  * use a global boolean to control
8801                  * whether TCP should respond to ICMP_SOURCE_QUENCH.
8802                  * The default is false.
8803                  */
8804                 if (tcp_icmp_source_quench) {
8805                         /*
8806                          * Reduce the sending rate as if we got a
8807                          * retransmit timeout
8808                          */
8809                         uint32_t npkt;
8810 
8811                         npkt = ((tcp->tcp_snxt - tcp->tcp_suna) >> 1) /
8812                             tcp->tcp_mss;
8813                         tcp->tcp_cwnd_ssthresh = MAX(npkt, 2) * tcp->tcp_mss;
8814                         tcp->tcp_cwnd = tcp->tcp_mss;
8815                         tcp->tcp_cwnd_cnt = 0;
8816                 }
8817                 break;
8818         }
8819         }
8820         freemsg(first_mp);
8821 }
8822 
8823 /*
8824  * tcp_icmp_error_ipv6 is called by tcp_rput_other to process ICMPv6
8825  * error messages passed up by IP.
8826  * Assumes that IP has pulled up all the extension headers as well
8827  * as the ICMPv6 header.
8828  */
8829 static void
8830 tcp_icmp_error_ipv6(tcp_t *tcp, mblk_t *mp, boolean_t ipsec_mctl)
8831 {
8832         icmp6_t *icmp6;
8833         ip6_t   *ip6h;
8834         uint16_t        iph_hdr_length;
8835         tcpha_t *tcpha;
8836         uint8_t *nexthdrp;
8837         uint32_t new_mss;
8838         uint32_t ratio;
8839         boolean_t secure;
8840         mblk_t *first_mp = mp;
8841         size_t mp_size;
8842         uint32_t seg_seq;
8843         tcp_stack_t     *tcps = tcp->tcp_tcps;
8844 
8845         /*
8846          * The caller has determined if this is an IPSEC_IN packet and
8847          * set ipsec_mctl appropriately (see tcp_icmp_error).
8848          */
8849         if (ipsec_mctl)
8850                 mp = mp->b_cont;
8851 
8852         mp_size = MBLKL(mp);
8853 
8854         /*
8855          * Verify that we have a complete IP header. If not, send it upstream.
8856          */
8857         if (mp_size < sizeof (ip6_t)) {
8858 noticmpv6:
8859                 freemsg(first_mp);
8860                 return;
8861         }
8862 
8863         /*
8864          * Verify this is an ICMPV6 packet, else send it upstream.
8865          */
8866         ip6h = (ip6_t *)mp->b_rptr;
8867         if (ip6h->ip6_nxt == IPPROTO_ICMPV6) {
8868                 iph_hdr_length = IPV6_HDR_LEN;
8869         } else if (!ip_hdr_length_nexthdr_v6(mp, ip6h, &iph_hdr_length,
8870             &nexthdrp) ||
8871             *nexthdrp != IPPROTO_ICMPV6) {
8872                 goto noticmpv6;
8873         }
8874         icmp6 = (icmp6_t *)&mp->b_rptr[iph_hdr_length];
8875         ip6h = (ip6_t *)&icmp6[1];
8876         /*
8877          * Verify if we have a complete ICMP and inner IP header.
8878          */
8879         if ((uchar_t *)&ip6h[1] > mp->b_wptr)
8880                 goto noticmpv6;
8881 
8882         if (!ip_hdr_length_nexthdr_v6(mp, ip6h, &iph_hdr_length, &nexthdrp))
8883                 goto noticmpv6;
8884         tcpha = (tcpha_t *)((char *)ip6h + iph_hdr_length);
8885         /*
8886          * Validate inner header. If the ULP is not IPPROTO_TCP or if we don't
8887          * have at least ICMP_MIN_TCP_HDR bytes of  TCP header drop the
8888          * packet.
8889          */
8890         if ((*nexthdrp != IPPROTO_TCP) ||
8891             ((uchar_t *)tcpha + ICMP_MIN_TCP_HDR) > mp->b_wptr) {
8892                 goto noticmpv6;
8893         }
8894 
8895         /*
8896          * ICMP errors come on the right queue or come on
8897          * listener/global queue for detached connections and
8898          * get switched to the right queue. If it comes on the
8899          * right queue, policy check has already been done by IP
8900          * and thus free the first_mp without verifying the policy.
8901          * If it has come for a non-hard bound connection, we need
8902          * to verify policy as IP may not have done it.
8903          */
8904         if (!tcp->tcp_hard_bound) {
8905                 if (ipsec_mctl) {
8906                         secure = ipsec_in_is_secure(first_mp);
8907                 } else {
8908                         secure = B_FALSE;
8909                 }
8910                 if (secure) {
8911                         /*
8912                          * If we are willing to accept this in clear
8913                          * we don't have to verify policy.
8914                          */
8915                         if (!ipsec_inbound_accept_clear(mp, NULL, ip6h)) {
8916                                 if (!tcp_check_policy(tcp, first_mp,
8917                                     NULL, ip6h, secure, ipsec_mctl)) {
8918                                         /*
8919                                          * tcp_check_policy called
8920                                          * ip_drop_packet() on failure.
8921                                          */
8922                                         return;
8923                                 }
8924                         }
8925                 }
8926         } else if (ipsec_mctl) {
8927                 /*
8928                  * This is a hard_bound connection. IP has already
8929                  * verified policy. We don't have to do it again.
8930                  */
8931                 freeb(first_mp);
8932                 first_mp = mp;
8933                 ipsec_mctl = B_FALSE;
8934         }
8935 
8936         seg_seq = ntohl(tcpha->tha_seq);
8937         /*
8938          * TCP SHOULD check that the TCP sequence number contained in
8939          * payload of the ICMP error message is within the range
8940          * SND.UNA <= SEG.SEQ < SND.NXT.
8941          */
8942         if (SEQ_LT(seg_seq, tcp->tcp_suna) || SEQ_GEQ(seg_seq, tcp->tcp_snxt)) {
8943                 /*
8944                  * If the ICMP message is bogus, should we kill the
8945                  * connection, or should we just drop the bogus ICMP
8946                  * message? It would probably make more sense to just
8947                  * drop the message so that if this one managed to get
8948                  * in, the real connection should not suffer.
8949                  */
8950                 goto noticmpv6;
8951         }
8952 
8953         switch (icmp6->icmp6_type) {
8954         case ICMP6_PACKET_TOO_BIG:
8955                 /*
8956                  * Reduce the MSS based on the new MTU.  This will
8957                  * eliminate any fragmentation locally.
8958                  * N.B.  There may well be some funny side-effects on
8959                  * the local send policy and the remote receive policy.
8960                  * Pending further research, we provide
8961                  * tcp_ignore_path_mtu just in case this proves
8962                  * disastrous somewhere.
8963                  *
8964                  * After updating the MSS, retransmit part of the
8965                  * dropped segment using the new mss by calling
8966                  * tcp_wput_data().  Need to adjust all those
8967                  * params to make sure tcp_wput_data() work properly.
8968                  */
8969                 if (tcps->tcps_ignore_path_mtu)
8970                         break;
8971 
8972                 /*
8973                  * Decrease the MSS by time stamp options
8974                  * IP options and IPSEC options. tcp_hdr_len
8975                  * includes time stamp option and IP option
8976                  * length.
8977                  */
8978                 new_mss = ntohs(icmp6->icmp6_mtu) - tcp->tcp_hdr_len -
8979                     tcp->tcp_ipsec_overhead;
8980 
8981                 /*
8982                  * Only update the MSS if the new one is
8983                  * smaller than the previous one.  This is
8984                  * to avoid problems when getting multiple
8985                  * ICMP errors for the same MTU.
8986                  */
8987                 if (new_mss >= tcp->tcp_mss)
8988                         break;
8989 
8990                 ratio = tcp->tcp_cwnd / tcp->tcp_mss;
8991                 ASSERT(ratio >= 1);
8992                 tcp_mss_set(tcp, new_mss, B_TRUE);
8993 
8994                 /*
8995                  * Make sure we have something to
8996                  * send.
8997                  */
8998                 if (SEQ_LT(tcp->tcp_suna, tcp->tcp_snxt) &&
8999                     (tcp->tcp_xmit_head != NULL)) {
9000                         /*
9001                          * Shrink tcp_cwnd in
9002                          * proportion to the old MSS/new MSS.
9003                          */
9004                         tcp->tcp_cwnd = ratio * tcp->tcp_mss;
9005                         if ((tcp->tcp_valid_bits & TCP_FSS_VALID) &&
9006                             (tcp->tcp_unsent == 0)) {
9007                                 tcp->tcp_rexmit_max = tcp->tcp_fss;
9008                         } else {
9009                                 tcp->tcp_rexmit_max = tcp->tcp_snxt;
9010                         }
9011                         tcp->tcp_rexmit_nxt = tcp->tcp_suna;
9012                         tcp->tcp_rexmit = B_TRUE;
9013                         tcp->tcp_dupack_cnt = 0;
9014                         tcp->tcp_snd_burst = TCP_CWND_SS;
9015                         tcp_ss_rexmit(tcp);
9016                 }
9017                 break;
9018 
9019         case ICMP6_DST_UNREACH:
9020                 switch (icmp6->icmp6_code) {
9021                 case ICMP6_DST_UNREACH_NOPORT:
9022                         if (((tcp->tcp_state == TCPS_SYN_SENT) ||
9023                             (tcp->tcp_state == TCPS_SYN_RCVD)) &&
9024                             (seg_seq == tcp->tcp_iss)) {
9025                                 (void) tcp_clean_death(tcp,
9026                                     ECONNREFUSED, 8);
9027                         }
9028                         break;
9029 
9030                 case ICMP6_DST_UNREACH_ADMIN:
9031                 case ICMP6_DST_UNREACH_NOROUTE:
9032                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
9033                 case ICMP6_DST_UNREACH_ADDR:
9034                         /* Record the error in case we finally time out. */
9035                         tcp->tcp_client_errno = EHOSTUNREACH;
9036                         if (((tcp->tcp_state == TCPS_SYN_SENT) ||
9037                             (tcp->tcp_state == TCPS_SYN_RCVD)) &&
9038                             (seg_seq == tcp->tcp_iss)) {
9039                                 if (tcp->tcp_listener != NULL &&
9040                                     tcp->tcp_listener->tcp_syn_defense) {
9041                                         /*
9042                                          * Ditch the half-open connection if we
9043                                          * suspect a SYN attack is under way.
9044                                          */
9045                                         tcp_ip_ire_mark_advice(tcp);
9046                                         (void) tcp_clean_death(tcp,
9047                                             tcp->tcp_client_errno, 9);
9048                                 }
9049                         }
9050 
9051 
9052                         break;
9053                 default:
9054                         break;
9055                 }
9056                 break;
9057 
9058         case ICMP6_PARAM_PROB:
9059                 /* If this corresponds to an ICMP_PROTOCOL_UNREACHABLE */
9060                 if (icmp6->icmp6_code == ICMP6_PARAMPROB_NEXTHEADER &&
9061                     (uchar_t *)ip6h + icmp6->icmp6_pptr ==
9062                     (uchar_t *)nexthdrp) {
9063                         if (tcp->tcp_state == TCPS_SYN_SENT ||
9064                             tcp->tcp_state == TCPS_SYN_RCVD) {
9065                                 (void) tcp_clean_death(tcp,
9066                                     ECONNREFUSED, 10);
9067                         }
9068                         break;
9069                 }
9070                 break;
9071 
9072         case ICMP6_TIME_EXCEEDED:
9073         default:
9074                 break;
9075         }
9076         freemsg(first_mp);
9077 }
9078 
9079 /*
9080  * IP recognizes seven kinds of bind requests:
9081  *
9082  * - A zero-length address binds only to the protocol number.
9083  *
9084  * - A 4-byte address is treated as a request to
9085  * validate that the address is a valid local IPv4
9086  * address, appropriate for an application to bind to.
9087  * IP does the verification, but does not make any note
9088  * of the address at this time.
9089  *
9090  * - A 16-byte address contains is treated as a request
9091  * to validate a local IPv6 address, as the 4-byte
9092  * address case above.
9093  *
9094  * - A 16-byte sockaddr_in to validate the local IPv4 address and also
9095  * use it for the inbound fanout of packets.
9096  *
9097  * - A 24-byte sockaddr_in6 to validate the local IPv6 address and also
9098  * use it for the inbound fanout of packets.
9099  *
9100  * - A 12-byte address (ipa_conn_t) containing complete IPv4 fanout
9101  * information consisting of local and remote addresses
9102  * and ports.  In this case, the addresses are both
9103  * validated as appropriate for this operation, and, if
9104  * so, the information is retained for use in the
9105  * inbound fanout.
9106  *
9107  * - A 36-byte address address (ipa6_conn_t) containing complete IPv6
9108  * fanout information, like the 12-byte case above.
9109  *
9110  * IP will also fill in the IRE request mblk with information
9111  * regarding our peer.  In all cases, we notify IP of our protocol
9112  * type by appending a single protocol byte to the bind request.
9113  */
9114 static mblk_t *
9115 tcp_ip_bind_mp(tcp_t *tcp, t_scalar_t bind_prim, t_scalar_t addr_length)
9116 {
9117         char    *cp;
9118         mblk_t  *mp;
9119         struct T_bind_req *tbr;
9120         ipa_conn_t      *ac;
9121         ipa6_conn_t     *ac6;
9122         sin_t           *sin;
9123         sin6_t          *sin6;
9124 
9125         ASSERT(bind_prim == O_T_BIND_REQ || bind_prim == T_BIND_REQ);
9126         ASSERT((tcp->tcp_family == AF_INET &&
9127             tcp->tcp_ipversion == IPV4_VERSION) ||
9128             (tcp->tcp_family == AF_INET6 &&
9129             (tcp->tcp_ipversion == IPV4_VERSION ||
9130             tcp->tcp_ipversion == IPV6_VERSION)));
9131 
9132         mp = allocb(sizeof (*tbr) + addr_length + 1, BPRI_HI);
9133         if (!mp)
9134                 return (mp);
9135         mp->b_datap->db_type = M_PROTO;
9136         tbr = (struct T_bind_req *)mp->b_rptr;
9137         tbr->PRIM_type = bind_prim;
9138         tbr->ADDR_offset = sizeof (*tbr);
9139         tbr->CONIND_number = 0;
9140         tbr->ADDR_length = addr_length;
9141         cp = (char *)&tbr[1];
9142         switch (addr_length) {
9143         case sizeof (ipa_conn_t):
9144                 ASSERT(tcp->tcp_family == AF_INET);
9145                 ASSERT(tcp->tcp_ipversion == IPV4_VERSION);
9146 
9147                 mp->b_cont = allocb(sizeof (ire_t), BPRI_HI);
9148                 if (mp->b_cont == NULL) {
9149                         freemsg(mp);
9150                         return (NULL);
9151                 }
9152                 mp->b_cont->b_wptr += sizeof (ire_t);
9153                 mp->b_cont->b_datap->db_type = IRE_DB_REQ_TYPE;
9154 
9155                 /* cp known to be 32 bit aligned */
9156                 ac = (ipa_conn_t *)cp;
9157                 ac->ac_laddr = tcp->tcp_ipha->ipha_src;
9158                 ac->ac_faddr = tcp->tcp_remote;
9159                 ac->ac_fport = tcp->tcp_fport;
9160                 ac->ac_lport = tcp->tcp_lport;
9161                 tcp->tcp_hard_binding = 1;
9162                 break;
9163 
9164         case sizeof (ipa6_conn_t):
9165                 ASSERT(tcp->tcp_family == AF_INET6);
9166 
9167                 mp->b_cont = allocb(sizeof (ire_t), BPRI_HI);
9168                 if (mp->b_cont == NULL) {
9169                         freemsg(mp);
9170                         return (NULL);
9171                 }
9172                 mp->b_cont->b_wptr += sizeof (ire_t);
9173                 mp->b_cont->b_datap->db_type = IRE_DB_REQ_TYPE;
9174 
9175                 /* cp known to be 32 bit aligned */
9176                 ac6 = (ipa6_conn_t *)cp;
9177                 if (tcp->tcp_ipversion == IPV4_VERSION) {
9178                         IN6_IPADDR_TO_V4MAPPED(tcp->tcp_ipha->ipha_src,
9179                             &ac6->ac6_laddr);
9180                 } else {
9181                         ac6->ac6_laddr = tcp->tcp_ip6h->ip6_src;
9182                 }
9183                 ac6->ac6_faddr = tcp->tcp_remote_v6;
9184                 ac6->ac6_fport = tcp->tcp_fport;
9185                 ac6->ac6_lport = tcp->tcp_lport;
9186                 tcp->tcp_hard_binding = 1;
9187                 break;
9188 
9189         case sizeof (sin_t):
9190                 /*
9191                  * NOTE: IPV6_ADDR_LEN also has same size.
9192                  * Use family to discriminate.
9193                  */
9194                 if (tcp->tcp_family == AF_INET) {
9195                         sin = (sin_t *)cp;
9196 
9197                         *sin = sin_null;
9198                         sin->sin_family = AF_INET;
9199                         sin->sin_addr.s_addr = tcp->tcp_bound_source;
9200                         sin->sin_port = tcp->tcp_lport;
9201                         break;
9202                 } else {
9203                         *(in6_addr_t *)cp = tcp->tcp_bound_source_v6;
9204                 }
9205                 break;
9206 
9207         case sizeof (sin6_t):
9208                 ASSERT(tcp->tcp_family == AF_INET6);
9209                 sin6 = (sin6_t *)cp;
9210 
9211                 *sin6 = sin6_null;
9212                 sin6->sin6_family = AF_INET6;
9213                 sin6->sin6_addr = tcp->tcp_bound_source_v6;
9214                 sin6->sin6_port = tcp->tcp_lport;
9215                 break;
9216 
9217         case IP_ADDR_LEN:
9218                 ASSERT(tcp->tcp_ipversion == IPV4_VERSION);
9219                 *(uint32_t *)cp = tcp->tcp_ipha->ipha_src;
9220                 break;
9221 
9222         }
9223         /* Add protocol number to end */
9224         cp[addr_length] = (char)IPPROTO_TCP;
9225         mp->b_wptr = (uchar_t *)&cp[addr_length + 1];
9226         return (mp);
9227 }
9228 
9229 /*
9230  * Notify IP that we are having trouble with this connection.  IP should
9231  * blow the IRE away and start over.
9232  */
9233 static void
9234 tcp_ip_notify(tcp_t *tcp)
9235 {
9236         struct iocblk   *iocp;
9237         ipid_t  *ipid;
9238         mblk_t  *mp;
9239 
9240         /* IPv6 has NUD thus notification to delete the IRE is not needed */
9241         if (tcp->tcp_ipversion == IPV6_VERSION)
9242                 return;
9243 
9244         mp = mkiocb(IP_IOCTL);
9245         if (mp == NULL)
9246                 return;
9247 
9248         iocp = (struct iocblk *)mp->b_rptr;
9249         iocp->ioc_count = sizeof (ipid_t) + sizeof (tcp->tcp_ipha->ipha_dst);
9250 
9251         mp->b_cont = allocb(iocp->ioc_count, BPRI_HI);
9252         if (!mp->b_cont) {
9253                 freeb(mp);
9254                 return;
9255         }
9256 
9257         ipid = (ipid_t *)mp->b_cont->b_rptr;
9258         mp->b_cont->b_wptr += iocp->ioc_count;
9259         bzero(ipid, sizeof (*ipid));
9260         ipid->ipid_cmd = IP_IOC_IRE_DELETE_NO_REPLY;
9261         ipid->ipid_ire_type = IRE_CACHE;
9262         ipid->ipid_addr_offset = sizeof (ipid_t);
9263         ipid->ipid_addr_length = sizeof (tcp->tcp_ipha->ipha_dst);
9264         /*
9265          * Note: in the case of source routing we want to blow away the
9266          * route to the first source route hop.
9267          */
9268         bcopy(&tcp->tcp_ipha->ipha_dst, &ipid[1],
9269             sizeof (tcp->tcp_ipha->ipha_dst));
9270 
9271         CALL_IP_WPUT(tcp->tcp_connp, tcp->tcp_wq, mp);
9272 }
9273 
9274 /* Unlink and return any mblk that looks like it contains an ire */
9275 static mblk_t *
9276 tcp_ire_mp(mblk_t *mp)
9277 {
9278         mblk_t  *prev_mp;
9279 
9280         for (;;) {
9281                 prev_mp = mp;
9282                 mp = mp->b_cont;
9283                 if (mp == NULL)
9284                         break;
9285                 switch (DB_TYPE(mp)) {
9286                 case IRE_DB_TYPE:
9287                 case IRE_DB_REQ_TYPE:
9288                         if (prev_mp != NULL)
9289                                 prev_mp->b_cont = mp->b_cont;
9290                         mp->b_cont = NULL;
9291                         return (mp);
9292                 default:
9293                         break;
9294                 }
9295         }
9296         return (mp);
9297 }
9298 
9299 /*
9300  * Timer callback routine for keepalive probe.  We do a fake resend of
9301  * last ACKed byte.  Then set a timer using RTO.  When the timer expires,
9302  * check to see if we have heard anything from the other end for the last
9303  * RTO period.  If we have, set the timer to expire for another
9304  * tcp_keepalive_intrvl and check again.  If we have not, set a timer using
9305  * RTO << 1 and check again when it expires.  Keep exponentially increasing
9306  * the timeout if we have not heard from the other side.  If for more than
9307  * (tcp_ka_interval + tcp_ka_abort_thres) we have not heard anything,
9308  * kill the connection unless the keepalive abort threshold is 0.  In
9309  * that case, we will probe "forever."
9310  */
9311 static void
9312 tcp_keepalive_killer(void *arg)
9313 {
9314         mblk_t  *mp;
9315         conn_t  *connp = (conn_t *)arg;
9316         tcp_t   *tcp = connp->conn_tcp;
9317         int32_t firetime;
9318         int32_t idletime;
9319         int32_t ka_intrvl;
9320         tcp_stack_t     *tcps = tcp->tcp_tcps;
9321 
9322         tcp->tcp_ka_tid = 0;
9323 
9324         if (tcp->tcp_fused)
9325                 return;
9326 
9327         BUMP_MIB(&tcps->tcps_mib, tcpTimKeepalive);
9328         ka_intrvl = tcp->tcp_ka_interval;
9329 
9330         /*
9331          * Keepalive probe should only be sent if the application has not
9332          * done a close on the connection.
9333          */
9334         if (tcp->tcp_state > TCPS_CLOSE_WAIT) {
9335                 return;
9336         }
9337         /* Timer fired too early, restart it. */
9338         if (tcp->tcp_state < TCPS_ESTABLISHED) {
9339                 tcp->tcp_ka_tid = TCP_TIMER(tcp, tcp_keepalive_killer,
9340                     MSEC_TO_TICK(ka_intrvl));
9341                 return;
9342         }
9343 
9344         idletime = TICK_TO_MSEC(lbolt - tcp->tcp_last_recv_time);
9345         /*
9346          * If we have not heard from the other side for a long
9347          * time, kill the connection unless the keepalive abort
9348          * threshold is 0.  In that case, we will probe "forever."
9349          */
9350         if (tcp->tcp_ka_abort_thres != 0 &&
9351             idletime > (ka_intrvl + tcp->tcp_ka_abort_thres)) {
9352                 BUMP_MIB(&tcps->tcps_mib, tcpTimKeepaliveDrop);
9353                 (void) tcp_clean_death(tcp, tcp->tcp_client_errno ?
9354                     tcp->tcp_client_errno : ETIMEDOUT, 11);
9355                 return;
9356         }
9357 
9358         if (tcp->tcp_snxt == tcp->tcp_suna &&
9359             idletime >= ka_intrvl) {
9360                 /* Fake resend of last ACKed byte. */
9361                 mblk_t  *mp1 = allocb(1, BPRI_LO);
9362 
9363                 if (mp1 != NULL) {
9364                         *mp1->b_wptr++ = '\0';
9365                         mp = tcp_xmit_mp(tcp, mp1, 1, NULL, NULL,
9366                             tcp->tcp_suna - 1, B_FALSE, NULL, B_TRUE);
9367                         freeb(mp1);
9368                         /*
9369                          * if allocation failed, fall through to start the
9370                          * timer back.
9371                          */
9372                         if (mp != NULL) {
9373                                 TCP_RECORD_TRACE(tcp, mp,
9374                                     TCP_TRACE_SEND_PKT);
9375                                 tcp_send_data(tcp, tcp->tcp_wq, mp);
9376                                 BUMP_MIB(&tcps->tcps_mib,
9377                                     tcpTimKeepaliveProbe);
9378                                 if (tcp->tcp_ka_last_intrvl != 0) {
9379                                         int max;
9380                                         /*
9381                                          * We should probe again at least
9382                                          * in ka_intrvl, but not more than
9383                                          * tcp_rexmit_interval_max.
9384                                          */
9385                                         max = tcps->tcps_rexmit_interval_max;
9386                                         firetime = MIN(ka_intrvl - 1,
9387                                             tcp->tcp_ka_last_intrvl << 1);
9388                                         if (firetime > max)
9389                                                 firetime = max;
9390                                 } else {
9391                                         firetime = tcp->tcp_rto;
9392                                 }
9393                                 tcp->tcp_ka_tid = TCP_TIMER(tcp,
9394                                     tcp_keepalive_killer,
9395                                     MSEC_TO_TICK(firetime));
9396                                 tcp->tcp_ka_last_intrvl = firetime;
9397                                 return;
9398                         }
9399                 }
9400         } else {
9401                 tcp->tcp_ka_last_intrvl = 0;
9402         }
9403 
9404         /* firetime can be negative if (mp1 == NULL || mp == NULL) */
9405         if ((firetime = ka_intrvl - idletime) < 0) {
9406                 firetime = ka_intrvl;
9407         }
9408         tcp->tcp_ka_tid = TCP_TIMER(tcp, tcp_keepalive_killer,
9409             MSEC_TO_TICK(firetime));
9410 }
9411 
9412 int
9413 tcp_maxpsz_set(tcp_t *tcp, boolean_t set_maxblk)
9414 {
9415         queue_t *q = tcp->tcp_rq;
9416         int32_t mss = tcp->tcp_mss;
9417         int     maxpsz;
9418 
9419         if (TCP_IS_DETACHED(tcp))
9420                 return (mss);
9421 
9422         if (tcp->tcp_fused) {
9423                 maxpsz = tcp_fuse_maxpsz_set(tcp);
9424                 mss = INFPSZ;
9425         } else if (tcp->tcp_mdt || tcp->tcp_lso || tcp->tcp_maxpsz == 0) {
9426                 /*
9427                  * Set the sd_qn_maxpsz according to the socket send buffer
9428                  * size, and sd_maxblk to INFPSZ (-1).  This will essentially
9429                  * instruct the stream head to copyin user data into contiguous
9430                  * kernel-allocated buffers without breaking it up into smaller
9431                  * chunks.  We round up the buffer size to the nearest SMSS.
9432                  */
9433                 maxpsz = MSS_ROUNDUP(tcp->tcp_xmit_hiwater, mss);
9434                 if (tcp->tcp_kssl_ctx == NULL)
9435                         mss = INFPSZ;
9436                 else
9437                         mss = SSL3_MAX_RECORD_LEN;
9438         } else {
9439                 /*
9440                  * Set sd_qn_maxpsz to approx half the (receivers) buffer
9441                  * (and a multiple of the mss).  This instructs the stream
9442                  * head to break down larger than SMSS writes into SMSS-
9443                  * size mblks, up to tcp_maxpsz_multiplier mblks at a time.
9444                  */
9445                 maxpsz = tcp->tcp_maxpsz * mss;
9446                 if (maxpsz > tcp->tcp_xmit_hiwater/2) {
9447                         maxpsz = tcp->tcp_xmit_hiwater/2;
9448                         /* Round up to nearest mss */
9449                         maxpsz = MSS_ROUNDUP(maxpsz, mss);
9450                 }
9451         }
9452         (void) setmaxps(q, maxpsz);
9453         tcp->tcp_wq->q_maxpsz = maxpsz;
9454 
9455         if (set_maxblk)
9456                 (void) mi_set_sth_maxblk(q, mss);
9457 
9458         return (mss);
9459 }
9460 
9461 /*
9462  * Extract option values from a tcp header.  We put any found values into the
9463  * tcpopt struct and return a bitmask saying which options were found.
9464  */
9465 static int
9466 tcp_parse_options(tcph_t *tcph, tcp_opt_t *tcpopt)
9467 {
9468         uchar_t         *endp;
9469         int             len;
9470         uint32_t        mss;
9471         uchar_t         *up = (uchar_t *)tcph;
9472         int             found = 0;
9473         int32_t         sack_len;
9474         tcp_seq         sack_begin, sack_end;
9475         tcp_t           *tcp;
9476 
9477         endp = up + TCP_HDR_LENGTH(tcph);
9478         up += TCP_MIN_HEADER_LENGTH;
9479         while (up < endp) {
9480                 len = endp - up;
9481                 switch (*up) {
9482                 case TCPOPT_EOL:
9483                         break;
9484 
9485                 case TCPOPT_NOP:
9486                         up++;
9487                         continue;
9488 
9489                 case TCPOPT_MAXSEG:
9490                         if (len < TCPOPT_MAXSEG_LEN ||
9491                             up[1] != TCPOPT_MAXSEG_LEN)
9492                                 break;
9493 
9494                         mss = BE16_TO_U16(up+2);
9495                         /* Caller must handle tcp_mss_min and tcp_mss_max_* */
9496                         tcpopt->tcp_opt_mss = mss;
9497                         found |= TCP_OPT_MSS_PRESENT;
9498 
9499                         up += TCPOPT_MAXSEG_LEN;
9500                         continue;
9501 
9502                 case TCPOPT_WSCALE:
9503                         if (len < TCPOPT_WS_LEN || up[1] != TCPOPT_WS_LEN)
9504                                 break;
9505 
9506                         if (up[2] > TCP_MAX_WINSHIFT)
9507                                 tcpopt->tcp_opt_wscale = TCP_MAX_WINSHIFT;
9508                         else
9509                                 tcpopt->tcp_opt_wscale = up[2];
9510                         found |= TCP_OPT_WSCALE_PRESENT;
9511 
9512                         up += TCPOPT_WS_LEN;
9513                         continue;
9514 
9515                 case TCPOPT_SACK_PERMITTED:
9516                         if (len < TCPOPT_SACK_OK_LEN ||
9517                             up[1] != TCPOPT_SACK_OK_LEN)
9518                                 break;
9519                         found |= TCP_OPT_SACK_OK_PRESENT;
9520                         up += TCPOPT_SACK_OK_LEN;
9521                         continue;
9522 
9523                 case TCPOPT_SACK:
9524                         if (len <= 2 || up[1] <= 2 || len < up[1])
9525                                 break;
9526 
9527                         /* If TCP is not interested in SACK blks... */
9528                         if ((tcp = tcpopt->tcp) == NULL) {
9529                                 up += up[1];
9530                                 continue;
9531                         }
9532                         sack_len = up[1] - TCPOPT_HEADER_LEN;
9533                         up += TCPOPT_HEADER_LEN;
9534 
9535                         /*
9536                          * If the list is empty, allocate one and assume
9537                          * nothing is sack'ed.
9538                          */
9539                         ASSERT(tcp->tcp_sack_info != NULL);
9540                         if (tcp->tcp_notsack_list == NULL) {
9541                                 tcp_notsack_update(&(tcp->tcp_notsack_list),
9542                                     tcp->tcp_suna, tcp->tcp_snxt,
9543                                     &(tcp->tcp_num_notsack_blk),
9544                                     &(tcp->tcp_cnt_notsack_list));
9545 
9546                                 /*
9547                                  * Make sure tcp_notsack_list is not NULL.
9548                                  * This happens when kmem_alloc(KM_NOSLEEP)
9549                                  * returns NULL.
9550                                  */
9551                                 if (tcp->tcp_notsack_list == NULL) {
9552                                         up += sack_len;
9553                                         continue;
9554                                 }
9555                                 tcp->tcp_fack = tcp->tcp_suna;
9556                         }
9557 
9558                         while (sack_len > 0) {
9559                                 if (up + 8 > endp) {
9560                                         up = endp;
9561                                         break;
9562                                 }
9563                                 sack_begin = BE32_TO_U32(up);
9564                                 up += 4;
9565                                 sack_end = BE32_TO_U32(up);
9566                                 up += 4;
9567                                 sack_len -= 8;
9568                                 /*
9569                                  * Bounds checking.  Make sure the SACK
9570                                  * info is within tcp_suna and tcp_snxt.
9571                                  * If this SACK blk is out of bound, ignore
9572                                  * it but continue to parse the following
9573                                  * blks.
9574                                  */
9575                                 if (SEQ_LEQ(sack_end, sack_begin) ||
9576                                     SEQ_LT(sack_begin, tcp->tcp_suna) ||
9577                                     SEQ_GT(sack_end, tcp->tcp_snxt)) {
9578                                         continue;
9579                                 }
9580                                 tcp_notsack_insert(&(tcp->tcp_notsack_list),
9581                                     sack_begin, sack_end,
9582                                     &(tcp->tcp_num_notsack_blk),
9583                                     &(tcp->tcp_cnt_notsack_list));
9584                                 if (SEQ_GT(sack_end, tcp->tcp_fack)) {
9585                                         tcp->tcp_fack = sack_end;
9586                                 }
9587                         }
9588                         found |= TCP_OPT_SACK_PRESENT;
9589                         continue;
9590 
9591                 case TCPOPT_TSTAMP:
9592                         if (len < TCPOPT_TSTAMP_LEN ||
9593                             up[1] != TCPOPT_TSTAMP_LEN)
9594                                 break;
9595 
9596                         tcpopt->tcp_opt_ts_val = BE32_TO_U32(up+2);
9597                         tcpopt->tcp_opt_ts_ecr = BE32_TO_U32(up+6);
9598 
9599                         found |= TCP_OPT_TSTAMP_PRESENT;
9600 
9601                         up += TCPOPT_TSTAMP_LEN;
9602                         continue;
9603 
9604                 default:
9605                         if (len <= 1 || len < (int)up[1] || up[1] == 0)
9606                                 break;
9607                         up += up[1];
9608                         continue;
9609                 }
9610                 break;
9611         }
9612         return (found);
9613 }
9614 
9615 /*
9616  * Set the mss associated with a particular tcp based on its current value,
9617  * and a new one passed in. Observe minimums and maximums, and reset
9618  * other state variables that we want to view as multiples of mss.
9619  *
9620  * This function is called mainly because values like tcp_mss, tcp_cwnd,
9621  * highwater marks etc. need to be initialized or adjusted.
9622  * 1) From tcp_process_options() when the other side's SYN/SYN-ACK
9623  *    packet arrives.
9624  * 2) We need to set a new MSS when ICMP_FRAGMENTATION_NEEDED or
9625  *    ICMP6_PACKET_TOO_BIG arrives.
9626  * 3) From tcp_paws_check() if the other side stops sending the timestamp,
9627  *    to increase the MSS to use the extra bytes available.
9628  *
9629  * Callers except tcp_paws_check() ensure that they only reduce mss.
9630  */
9631 static void
9632 tcp_mss_set(tcp_t *tcp, uint32_t mss, boolean_t do_ss)
9633 {
9634         uint32_t        mss_max;
9635         tcp_stack_t     *tcps = tcp->tcp_tcps;
9636 
9637         if (tcp->tcp_ipversion == IPV4_VERSION)
9638                 mss_max = tcps->tcps_mss_max_ipv4;
9639         else
9640                 mss_max = tcps->tcps_mss_max_ipv6;
9641 
9642         if (mss < tcps->tcps_mss_min)
9643                 mss = tcps->tcps_mss_min;
9644         if (mss > mss_max)
9645                 mss = mss_max;
9646         /*
9647          * Unless naglim has been set by our client to
9648          * a non-mss value, force naglim to track mss.
9649          * This can help to aggregate small writes.
9650          */
9651         if (mss < tcp->tcp_naglim || tcp->tcp_mss == tcp->tcp_naglim)
9652                 tcp->tcp_naglim = mss;
9653         /*
9654          * TCP should be able to buffer at least 4 MSS data for obvious
9655          * performance reason.
9656          */
9657         if ((mss << 2) > tcp->tcp_xmit_hiwater)
9658                 tcp->tcp_xmit_hiwater = mss << 2;
9659 
9660         if (do_ss) {
9661                 /*
9662                  * Either the tcp_cwnd is as yet uninitialized, or mss is
9663                  * changing due to a reduction in MTU, presumably as a
9664                  * result of a new path component, reset cwnd to its
9665                  * "initial" value, as a multiple of the new mss.
9666                  */
9667                 SET_TCP_INIT_CWND(tcp, mss, tcps->tcps_slow_start_initial);
9668         } else {
9669                 /*
9670                  * Called by tcp_paws_check(), the mss increased
9671                  * marginally to allow use of space previously taken
9672                  * by the timestamp option. It would be inappropriate
9673                  * to apply slow start or tcp_init_cwnd values to
9674                  * tcp_cwnd, simply adjust to a multiple of the new mss.
9675                  */
9676                 tcp->tcp_cwnd = (tcp->tcp_cwnd / tcp->tcp_mss) * mss;
9677                 tcp->tcp_cwnd_cnt = 0;
9678         }
9679         tcp->tcp_mss = mss;
9680         (void) tcp_maxpsz_set(tcp, B_TRUE);
9681 }
9682 
9683 /* For /dev/tcp aka AF_INET open */
9684 static int
9685 tcp_openv4(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp)
9686 {
9687         return (tcp_open(q, devp, flag, sflag, credp, B_FALSE));
9688 }
9689 
9690 /* For /dev/tcp6 aka AF_INET6 open */
9691 static int
9692 tcp_openv6(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp)
9693 {
9694         return (tcp_open(q, devp, flag, sflag, credp, B_TRUE));
9695 }
9696 
9697 static int
9698 tcp_open(queue_t *q, dev_t *devp, int flag, int sflag, cred_t *credp,
9699     boolean_t isv6)
9700 {
9701         tcp_t           *tcp = NULL;
9702         conn_t          *connp;
9703         int             err;
9704         vmem_t          *minor_arena = NULL;
9705         dev_t           conn_dev;
9706         zoneid_t        zoneid;
9707         tcp_stack_t     *tcps = NULL;
9708 
9709         if (q->q_ptr != NULL)
9710                 return (0);
9711 
9712         if (sflag == MODOPEN)
9713                 return (EINVAL);
9714 
9715         if (!(flag & SO_ACCEPTOR)) {
9716                 /*
9717                  * Special case for install: miniroot needs to be able to
9718                  * access files via NFS as though it were always in the
9719                  * global zone.
9720                  */
9721                 if (credp == kcred && nfs_global_client_only != 0) {
9722                         zoneid = GLOBAL_ZONEID;
9723                         tcps = netstack_find_by_stackid(GLOBAL_NETSTACKID)->
9724                             netstack_tcp;
9725                         ASSERT(tcps != NULL);
9726                 } else {
9727                         netstack_t *ns;
9728 
9729                         ns = netstack_find_by_cred(credp);
9730                         ASSERT(ns != NULL);
9731                         tcps = ns->netstack_tcp;
9732                         ASSERT(tcps != NULL);
9733 
9734                         /*
9735                          * For exclusive stacks we set the zoneid to zero
9736                          * to make TCP operate as if in the global zone.
9737                          */
9738                         if (tcps->tcps_netstack->netstack_stackid !=
9739                             GLOBAL_NETSTACKID)
9740                                 zoneid = GLOBAL_ZONEID;
9741                         else
9742                                 zoneid = crgetzoneid(credp);
9743                 }
9744                 /*
9745                  * For stackid zero this is done from strplumb.c, but
9746                  * non-zero stackids are handled here.
9747                  */
9748                 if (tcps->tcps_g_q == NULL &&
9749                     tcps->tcps_netstack->netstack_stackid !=
9750                     GLOBAL_NETSTACKID) {
9751                         tcp_g_q_setup(tcps);
9752                 }
9753         }
9754 
9755         if ((ip_minor_arena_la != NULL) && (flag & SO_SOCKSTR) &&
9756             ((conn_dev = inet_minor_alloc(ip_minor_arena_la)) != 0)) {
9757                 minor_arena = ip_minor_arena_la;
9758         } else {
9759                 /*
9760                  * Either minor numbers in the large arena were exhausted
9761                  * or a non socket application is doing the open.
9762                  * Try to allocate from the small arena.
9763                  */
9764                 if ((conn_dev = inet_minor_alloc(ip_minor_arena_sa)) == 0) {
9765                         if (tcps != NULL)
9766                                 netstack_rele(tcps->tcps_netstack);
9767                         return (EBUSY);
9768                 }
9769                 minor_arena = ip_minor_arena_sa;
9770         }
9771         ASSERT(minor_arena != NULL);
9772 
9773         *devp = makedevice(getemajor(*devp), (minor_t)conn_dev);
9774 
9775         if (flag & SO_ACCEPTOR) {
9776                 /* No netstack_find_by_cred, hence no netstack_rele needed */
9777                 ASSERT(tcps == NULL);
9778                 q->q_qinfo = &tcp_acceptor_rinit;
9779                 /*
9780                  * the conn_dev and minor_arena will be subsequently used by
9781                  * tcp_wput_accept() and tcpclose_accept() to figure out the
9782                  * minor device number for this connection from the q_ptr.
9783                  */
9784                 RD(q)->q_ptr = (void *)conn_dev;
9785                 WR(q)->q_qinfo = &tcp_acceptor_winit;
9786                 WR(q)->q_ptr = (void *)minor_arena;
9787                 qprocson(q);
9788                 return (0);
9789         }
9790 
9791         connp = (conn_t *)tcp_get_conn(IP_SQUEUE_GET(lbolt), tcps);
9792         /*
9793          * Both tcp_get_conn and netstack_find_by_cred incremented refcnt,
9794          * so we drop it by one.
9795          */
9796         netstack_rele(tcps->tcps_netstack);
9797         if (connp == NULL) {
9798                 inet_minor_free(minor_arena, conn_dev);
9799                 q->q_ptr = NULL;
9800                 return (ENOSR);
9801         }
9802         connp->conn_sqp = IP_SQUEUE_GET(lbolt);
9803         tcp = connp->conn_tcp;
9804 
9805         q->q_ptr = WR(q)->q_ptr = connp;
9806         if (isv6) {
9807                 connp->conn_flags |= (IPCL_TCP6|IPCL_ISV6);
9808                 connp->conn_send = ip_output_v6;
9809                 connp->conn_af_isv6 = B_TRUE;
9810                 connp->conn_pkt_isv6 = B_TRUE;
9811                 connp->conn_src_preferences = IPV6_PREFER_SRC_DEFAULT;
9812                 tcp->tcp_ipversion = IPV6_VERSION;
9813                 tcp->tcp_family = AF_INET6;
9814                 tcp->tcp_mss = tcps->tcps_mss_def_ipv6;
9815         } else {
9816                 connp->conn_flags |= IPCL_TCP4;
9817                 connp->conn_send = ip_output;
9818                 connp->conn_af_isv6 = B_FALSE;
9819                 connp->conn_pkt_isv6 = B_FALSE;
9820                 tcp->tcp_ipversion = IPV4_VERSION;
9821                 tcp->tcp_family = AF_INET;
9822                 tcp->tcp_mss = tcps->tcps_mss_def_ipv4;
9823         }
9824 
9825         /*
9826          * TCP keeps a copy of cred for cache locality reasons but
9827          * we put a reference only once. If connp->conn_cred
9828          * becomes invalid, tcp_cred should also be set to NULL.
9829          */
9830         tcp->tcp_cred = connp->conn_cred = credp;
9831         crhold(connp->conn_cred);
9832         tcp->tcp_cpid = curproc->p_pid;
9833         tcp->tcp_open_time = lbolt64;
9834         connp->conn_zoneid = zoneid;
9835         connp->conn_mlp_type = mlptSingle;
9836         connp->conn_ulp_labeled = !is_system_labeled();
9837         ASSERT(connp->conn_netstack == tcps->tcps_netstack);
9838         ASSERT(tcp->tcp_tcps == tcps);
9839 
9840         /*
9841          * If the caller has the process-wide flag set, then default to MAC
9842          * exempt mode.  This allows read-down to unlabeled hosts.
9843          */
9844         if (getpflags(NET_MAC_AWARE, credp) != 0)
9845                 connp->conn_mac_exempt = B_TRUE;
9846 
9847         connp->conn_dev = conn_dev;
9848         connp->conn_minor_arena = minor_arena;
9849 
9850         ASSERT(q->q_qinfo == &tcp_rinitv4 || q->q_qinfo == &tcp_rinitv6);
9851         ASSERT(WR(q)->q_qinfo == &tcp_winit);
9852 
9853         if (flag & SO_SOCKSTR) {
9854                 /*
9855                  * No need to insert a socket in tcp acceptor hash.
9856                  * If it was a socket acceptor stream, we dealt with
9857                  * it above. A socket listener can never accept a
9858                  * connection and doesn't need acceptor_id.
9859                  */
9860                 connp->conn_flags |= IPCL_SOCKET;
9861                 tcp->tcp_issocket = 1;
9862                 WR(q)->q_qinfo = &tcp_sock_winit;
9863         } else {
9864 #ifdef  _ILP32
9865                 tcp->tcp_acceptor_id = (t_uscalar_t)RD(q);
9866 #else
9867                 tcp->tcp_acceptor_id = conn_dev;
9868 #endif  /* _ILP32 */
9869                 tcp_acceptor_hash_insert(tcp->tcp_acceptor_id, tcp);
9870         }
9871 
9872         if (tcps->tcps_trace)
9873                 tcp->tcp_tracebuf = kmem_zalloc(sizeof (tcptrch_t), KM_SLEEP);
9874 
9875         err = tcp_init(tcp, q);
9876         if (err != 0) {
9877                 inet_minor_free(connp->conn_minor_arena, connp->conn_dev);
9878                 tcp_acceptor_hash_remove(tcp);
9879                 CONN_DEC_REF(connp);
9880                 q->q_ptr = WR(q)->q_ptr = NULL;
9881                 return (err);
9882         }
9883 
9884         RD(q)->q_hiwat = tcps->tcps_recv_hiwat;
9885         tcp->tcp_rwnd = tcps->tcps_recv_hiwat;
9886 
9887         /* Non-zero default values */
9888         connp->conn_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
9889         /*
9890          * Put the ref for TCP. Ref for IP was already put
9891          * by ipcl_conn_create. Also Make the conn_t globally
9892          * visible to walkers
9893          */
9894         mutex_enter(&connp->conn_lock);
9895         CONN_INC_REF_LOCKED(connp);
9896         ASSERT(connp->conn_ref == 2);
9897         connp->conn_state_flags &= ~CONN_INCIPIENT;
9898         mutex_exit(&connp->conn_lock);
9899 
9900         qprocson(q);
9901         return (0);
9902 }
9903 
9904 /*
9905  * Some TCP options can be "set" by requesting them in the option
9906  * buffer. This is needed for XTI feature test though we do not
9907  * allow it in general. We interpret that this mechanism is more
9908  * applicable to OSI protocols and need not be allowed in general.
9909  * This routine filters out options for which it is not allowed (most)
9910  * and lets through those (few) for which it is. [ The XTI interface
9911  * test suite specifics will imply that any XTI_GENERIC level XTI_* if
9912  * ever implemented will have to be allowed here ].
9913  */
9914 static boolean_t
9915 tcp_allow_connopt_set(int level, int name)
9916 {
9917 
9918         switch (level) {
9919         case IPPROTO_TCP:
9920                 switch (name) {
9921                 case TCP_NODELAY:
9922                         return (B_TRUE);
9923                 default:
9924                         return (B_FALSE);
9925                 }
9926                 /*NOTREACHED*/
9927         default:
9928                 return (B_FALSE);
9929         }
9930         /*NOTREACHED*/
9931 }
9932 
9933 /*
9934  * This routine gets default values of certain options whose default
9935  * values are maintained by protocol specific code
9936  */
9937 /* ARGSUSED */
9938 int
9939 tcp_opt_default(queue_t *q, int level, int name, uchar_t *ptr)
9940 {
9941         int32_t *i1 = (int32_t *)ptr;
9942         tcp_stack_t     *tcps = Q_TO_TCP(q)->tcp_tcps;
9943 
9944         switch (level) {
9945         case IPPROTO_TCP:
9946                 switch (name) {
9947                 case TCP_NOTIFY_THRESHOLD:
9948                         *i1 = tcps->tcps_ip_notify_interval;
9949                         break;
9950                 case TCP_ABORT_THRESHOLD:
9951                         *i1 = tcps->tcps_ip_abort_interval;
9952                         break;
9953                 case TCP_CONN_NOTIFY_THRESHOLD:
9954                         *i1 = tcps->tcps_ip_notify_cinterval;
9955                         break;
9956                 case TCP_CONN_ABORT_THRESHOLD:
9957                         *i1 = tcps->tcps_ip_abort_cinterval;
9958                         break;
9959                 default:
9960                         return (-1);
9961                 }
9962                 break;
9963         case IPPROTO_IP:
9964                 switch (name) {
9965                 case IP_TTL:
9966                         *i1 = tcps->tcps_ipv4_ttl;
9967                         break;
9968                 default:
9969                         return (-1);
9970                 }
9971                 break;
9972         case IPPROTO_IPV6:
9973                 switch (name) {
9974                 case IPV6_UNICAST_HOPS:
9975                         *i1 = tcps->tcps_ipv6_hoplimit;
9976                         break;
9977                 default:
9978                         return (-1);
9979                 }
9980                 break;
9981         default:
9982                 return (-1);
9983         }
9984         return (sizeof (int));
9985 }
9986 
9987 
9988 /*
9989  * TCP routine to get the values of options.
9990  */
9991 int
9992 tcp_opt_get(queue_t *q, int level, int  name, uchar_t *ptr)
9993 {
9994         int             *i1 = (int *)ptr;
9995         conn_t          *connp = Q_TO_CONN(q);
9996         tcp_t           *tcp = connp->conn_tcp;
9997         ip6_pkt_t       *ipp = &tcp->tcp_sticky_ipp;
9998 
9999         switch (level) {
10000         case SOL_SOCKET:
10001                 switch (name) {
10002                 case SO_LINGER: {
10003                         struct linger *lgr = (struct linger *)ptr;
10004 
10005                         lgr->l_onoff = tcp->tcp_linger ? SO_LINGER : 0;
10006                         lgr->l_linger = tcp->tcp_lingertime;
10007                         }
10008                         return (sizeof (struct linger));
10009                 case SO_DEBUG:
10010                         *i1 = tcp->tcp_debug ? SO_DEBUG : 0;
10011                         break;
10012                 case SO_KEEPALIVE:
10013                         *i1 = tcp->tcp_ka_enabled ? SO_KEEPALIVE : 0;
10014                         break;
10015                 case SO_DONTROUTE:
10016                         *i1 = tcp->tcp_dontroute ? SO_DONTROUTE : 0;
10017                         break;
10018                 case SO_USELOOPBACK:
10019                         *i1 = tcp->tcp_useloopback ? SO_USELOOPBACK : 0;
10020                         break;
10021                 case SO_BROADCAST:
10022                         *i1 = tcp->tcp_broadcast ? SO_BROADCAST : 0;
10023                         break;
10024                 case SO_REUSEADDR:
10025                         *i1 = tcp->tcp_reuseaddr ? SO_REUSEADDR : 0;
10026                         break;
10027                 case SO_OOBINLINE:
10028                         *i1 = tcp->tcp_oobinline ? SO_OOBINLINE : 0;
10029                         break;
10030                 case SO_DGRAM_ERRIND:
10031                         *i1 = tcp->tcp_dgram_errind ? SO_DGRAM_ERRIND : 0;
10032                         break;
10033                 case SO_TYPE:
10034                         *i1 = SOCK_STREAM;
10035                         break;
10036                 case SO_SNDBUF:
10037                         *i1 = tcp->tcp_xmit_hiwater;
10038                         break;
10039                 case SO_RCVBUF:
10040                         *i1 = RD(q)->q_hiwat;
10041                         break;
10042                 case SO_SND_COPYAVOID:
10043                         *i1 = tcp->tcp_snd_zcopy_on ?
10044                             SO_SND_COPYAVOID : 0;
10045                         break;
10046                 case SO_ALLZONES:
10047                         *i1 = connp->conn_allzones ? 1 : 0;
10048                         break;
10049                 case SO_ANON_MLP:
10050                         *i1 = connp->conn_anon_mlp;
10051                         break;
10052                 case SO_MAC_EXEMPT:
10053                         *i1 = connp->conn_mac_exempt;
10054                         break;
10055                 case SO_EXCLBIND:
10056                         *i1 = tcp->tcp_exclbind ? SO_EXCLBIND : 0;
10057                         break;
10058                 case SO_PROTOTYPE:
10059                         *i1 = IPPROTO_TCP;
10060                         break;
10061                 case SO_DOMAIN:
10062                         *i1 = tcp->tcp_family;
10063                         break;
10064                 default:
10065                         return (-1);
10066                 }
10067                 break;
10068         case IPPROTO_TCP:
10069                 switch (name) {
10070                 case TCP_NODELAY:
10071                         *i1 = (tcp->tcp_naglim == 1) ? TCP_NODELAY : 0;
10072                         break;
10073                 case TCP_MAXSEG:
10074                         *i1 = tcp->tcp_mss;
10075                         break;
10076                 case TCP_NOTIFY_THRESHOLD:
10077                         *i1 = (int)tcp->tcp_first_timer_threshold;
10078                         break;
10079                 case TCP_ABORT_THRESHOLD:
10080                         *i1 = tcp->tcp_second_timer_threshold;
10081                         break;
10082                 case TCP_CONN_NOTIFY_THRESHOLD:
10083                         *i1 = tcp->tcp_first_ctimer_threshold;
10084                         break;
10085                 case TCP_CONN_ABORT_THRESHOLD:
10086                         *i1 = tcp->tcp_second_ctimer_threshold;
10087                         break;
10088                 case TCP_RECVDSTADDR:
10089                         *i1 = tcp->tcp_recvdstaddr;
10090                         break;
10091                 case TCP_ANONPRIVBIND:
10092                         *i1 = tcp->tcp_anon_priv_bind;
10093                         break;
10094                 case TCP_EXCLBIND:
10095                         *i1 = tcp->tcp_exclbind ? TCP_EXCLBIND : 0;
10096                         break;
10097                 case TCP_INIT_CWND:
10098                         *i1 = tcp->tcp_init_cwnd;
10099                         break;
10100                 case TCP_KEEPALIVE_THRESHOLD:
10101                         *i1 = tcp->tcp_ka_interval;
10102                         break;
10103                 case TCP_KEEPALIVE_ABORT_THRESHOLD:
10104                         *i1 = tcp->tcp_ka_abort_thres;
10105                         break;
10106                 case TCP_CORK:
10107                         *i1 = tcp->tcp_cork;
10108                         break;
10109                 default:
10110                         return (-1);
10111                 }
10112                 break;
10113         case IPPROTO_IP:
10114                 if (tcp->tcp_family != AF_INET)
10115                         return (-1);
10116                 switch (name) {
10117                 case IP_OPTIONS:
10118                 case T_IP_OPTIONS: {
10119                         /*
10120                          * This is compatible with BSD in that in only return
10121                          * the reverse source route with the final destination
10122                          * as the last entry. The first 4 bytes of the option
10123                          * will contain the final destination.
10124                          */
10125                         int     opt_len;
10126 
10127                         opt_len = (char *)tcp->tcp_tcph - (char *)tcp->tcp_ipha;
10128                         opt_len -= tcp->tcp_label_len + IP_SIMPLE_HDR_LENGTH;
10129                         ASSERT(opt_len >= 0);
10130                         /* Caller ensures enough space */
10131                         if (opt_len > 0) {
10132                                 /*
10133                                  * TODO: Do we have to handle getsockopt on an
10134                                  * initiator as well?
10135                                  */
10136                                 return (ip_opt_get_user(tcp->tcp_ipha, ptr));
10137                         }
10138                         return (0);
10139                         }
10140                 case IP_TOS:
10141                 case T_IP_TOS:
10142                         *i1 = (int)tcp->tcp_ipha->ipha_type_of_service;
10143                         break;
10144                 case IP_TTL:
10145                         *i1 = (int)tcp->tcp_ipha->ipha_ttl;
10146                         break;
10147                 case IP_NEXTHOP:
10148                         /* Handled at IP level */
10149                         return (-EINVAL);
10150                 default:
10151                         return (-1);
10152                 }
10153                 break;
10154         case IPPROTO_IPV6:
10155                 /*
10156                  * IPPROTO_IPV6 options are only supported for sockets
10157                  * that are using IPv6 on the wire.
10158                  */
10159                 if (tcp->tcp_ipversion != IPV6_VERSION) {
10160                         return (-1);
10161                 }
10162                 switch (name) {
10163                 case IPV6_UNICAST_HOPS:
10164                         *i1 = (unsigned int) tcp->tcp_ip6h->ip6_hops;
10165                         break;  /* goto sizeof (int) option return */
10166                 case IPV6_BOUND_IF:
10167                         /* Zero if not set */
10168                         *i1 = tcp->tcp_bound_if;
10169                         break;  /* goto sizeof (int) option return */
10170                 case IPV6_RECVPKTINFO:
10171                         if (tcp->tcp_ipv6_recvancillary & TCP_IPV6_RECVPKTINFO)
10172                                 *i1 = 1;
10173                         else
10174                                 *i1 = 0;
10175                         break;  /* goto sizeof (int) option return */
10176                 case IPV6_RECVTCLASS:
10177                         if (tcp->tcp_ipv6_recvancillary & TCP_IPV6_RECVTCLASS)
10178                                 *i1 = 1;
10179                         else
10180                                 *i1 = 0;
10181                         break;  /* goto sizeof (int) option return */
10182                 case IPV6_RECVHOPLIMIT:
10183                         if (tcp->tcp_ipv6_recvancillary &
10184                             TCP_IPV6_RECVHOPLIMIT)
10185                                 *i1 = 1;
10186                         else
10187                                 *i1 = 0;
10188                         break;  /* goto sizeof (int) option return */
10189                 case IPV6_RECVHOPOPTS:
10190                         if (tcp->tcp_ipv6_recvancillary & TCP_IPV6_RECVHOPOPTS)
10191                                 *i1 = 1;
10192                         else
10193                                 *i1 = 0;
10194                         break;  /* goto sizeof (int) option return */
10195                 case IPV6_RECVDSTOPTS:
10196                         if (tcp->tcp_ipv6_recvancillary & TCP_IPV6_RECVDSTOPTS)
10197                                 *i1 = 1;
10198                         else
10199                                 *i1 = 0;
10200                         break;  /* goto sizeof (int) option return */
10201                 case _OLD_IPV6_RECVDSTOPTS:
10202                         if (tcp->tcp_ipv6_recvancillary &
10203                             TCP_OLD_IPV6_RECVDSTOPTS)
10204                                 *i1 = 1;
10205                         else
10206                                 *i1 = 0;
10207                         break;  /* goto sizeof (int) option return */
10208                 case IPV6_RECVRTHDR:
10209                         if (tcp->tcp_ipv6_recvancillary & TCP_IPV6_RECVRTHDR)
10210                                 *i1 = 1;
10211                         else
10212                                 *i1 = 0;
10213                         break;  /* goto sizeof (int) option return */
10214                 case IPV6_RECVRTHDRDSTOPTS:
10215                         if (tcp->tcp_ipv6_recvancillary &
10216                             TCP_IPV6_RECVRTDSTOPTS)
10217                                 *i1 = 1;
10218                         else
10219                                 *i1 = 0;
10220                         break;  /* goto sizeof (int) option return */
10221                 case IPV6_PKTINFO: {
10222                         /* XXX assumes that caller has room for max size! */
10223                         struct in6_pktinfo *pkti;
10224 
10225                         pkti = (struct in6_pktinfo *)ptr;
10226                         if (ipp->ipp_fields & IPPF_IFINDEX)
10227                                 pkti->ipi6_ifindex = ipp->ipp_ifindex;
10228                         else
10229                                 pkti->ipi6_ifindex = 0;
10230                         if (ipp->ipp_fields & IPPF_ADDR)
10231                                 pkti->ipi6_addr = ipp->ipp_addr;
10232                         else
10233                                 pkti->ipi6_addr = ipv6_all_zeros;
10234                         return (sizeof (struct in6_pktinfo));
10235                 }
10236                 case IPV6_TCLASS:
10237                         if (ipp->ipp_fields & IPPF_TCLASS)
10238                                 *i1 = ipp->ipp_tclass;
10239                         else
10240                                 *i1 = IPV6_FLOW_TCLASS(
10241                                     IPV6_DEFAULT_VERS_AND_FLOW);
10242                         break;  /* goto sizeof (int) option return */
10243                 case IPV6_NEXTHOP: {
10244                         sin6_t *sin6 = (sin6_t *)ptr;
10245 
10246                         if (!(ipp->ipp_fields & IPPF_NEXTHOP))
10247                                 return (0);
10248                         *sin6 = sin6_null;
10249                         sin6->sin6_family = AF_INET6;
10250                         sin6->sin6_addr = ipp->ipp_nexthop;
10251                         return (sizeof (sin6_t));
10252                 }
10253                 case IPV6_HOPOPTS:
10254                         if (!(ipp->ipp_fields & IPPF_HOPOPTS))
10255                                 return (0);
10256                         if (ipp->ipp_hopoptslen <= tcp->tcp_label_len)
10257                                 return (0);
10258                         bcopy((char *)ipp->ipp_hopopts + tcp->tcp_label_len,
10259                             ptr, ipp->ipp_hopoptslen - tcp->tcp_label_len);
10260                         if (tcp->tcp_label_len > 0) {
10261                                 ptr[0] = ((char *)ipp->ipp_hopopts)[0];
10262                                 ptr[1] = (ipp->ipp_hopoptslen -
10263                                     tcp->tcp_label_len + 7) / 8 - 1;
10264                         }
10265                         return (ipp->ipp_hopoptslen - tcp->tcp_label_len);
10266                 case IPV6_RTHDRDSTOPTS:
10267                         if (!(ipp->ipp_fields & IPPF_RTDSTOPTS))
10268                                 return (0);
10269                         bcopy(ipp->ipp_rtdstopts, ptr, ipp->ipp_rtdstoptslen);
10270                         return (ipp->ipp_rtdstoptslen);
10271                 case IPV6_RTHDR:
10272                         if (!(ipp->ipp_fields & IPPF_RTHDR))
10273                                 return (0);
10274                         bcopy(ipp->ipp_rthdr, ptr, ipp->ipp_rthdrlen);
10275                         return (ipp->ipp_rthdrlen);
10276                 case IPV6_DSTOPTS:
10277                         if (!(ipp->ipp_fields & IPPF_DSTOPTS))
10278                                 return (0);
10279                         bcopy(ipp->ipp_dstopts, ptr, ipp->ipp_dstoptslen);
10280                         return (ipp->ipp_dstoptslen);
10281                 case IPV6_SRC_PREFERENCES:
10282                         return (ip6_get_src_preferences(connp,
10283                             (uint32_t *)ptr));
10284                 case IPV6_PATHMTU: {
10285                         struct ip6_mtuinfo *mtuinfo = (struct ip6_mtuinfo *)ptr;
10286 
10287                         if (tcp->tcp_state < TCPS_ESTABLISHED)
10288                                 return (-1);
10289 
10290                         return (ip_fill_mtuinfo(&connp->conn_remv6,
10291                             connp->conn_fport, mtuinfo,
10292                             connp->conn_netstack));
10293                 }
10294                 default:
10295                         return (-1);
10296                 }
10297                 break;
10298         default:
10299                 return (-1);
10300         }
10301         return (sizeof (int));
10302 }
10303 
10304 /*
10305  * We declare as 'int' rather than 'void' to satisfy pfi_t arg requirements.
10306  * Parameters are assumed to be verified by the caller.
10307  */
10308 /* ARGSUSED */
10309 int
10310 tcp_opt_set(queue_t *q, uint_t optset_context, int level, int name,
10311     uint_t inlen, uchar_t *invalp, uint_t *outlenp, uchar_t *outvalp,
10312     void *thisdg_attrs, cred_t *cr, mblk_t *mblk)
10313 {
10314         conn_t  *connp = Q_TO_CONN(q);
10315         tcp_t   *tcp = connp->conn_tcp;
10316         int     *i1 = (int *)invalp;
10317         boolean_t onoff = (*i1 == 0) ? 0 : 1;
10318         boolean_t checkonly;
10319         int     reterr;
10320         tcp_stack_t     *tcps = Q_TO_TCP(q)->tcp_tcps;
10321 
10322         switch (optset_context) {
10323         case SETFN_OPTCOM_CHECKONLY:
10324                 checkonly = B_TRUE;
10325                 /*
10326                  * Note: Implies T_CHECK semantics for T_OPTCOM_REQ
10327                  * inlen != 0 implies value supplied and
10328                  *      we have to "pretend" to set it.
10329                  * inlen == 0 implies that there is no
10330                  *      value part in T_CHECK request and just validation
10331                  * done elsewhere should be enough, we just return here.
10332                  */
10333                 if (inlen == 0) {
10334                         *outlenp = 0;
10335                         return (0);
10336                 }
10337                 break;
10338         case SETFN_OPTCOM_NEGOTIATE:
10339                 checkonly = B_FALSE;
10340                 break;
10341         case SETFN_UD_NEGOTIATE: /* error on conn-oriented transports ? */
10342         case SETFN_CONN_NEGOTIATE:
10343                 checkonly = B_FALSE;
10344                 /*
10345                  * Negotiating local and "association-related" options
10346                  * from other (T_CONN_REQ, T_CONN_RES,T_UNITDATA_REQ)
10347                  * primitives is allowed by XTI, but we choose
10348                  * to not implement this style negotiation for Internet
10349                  * protocols (We interpret it is a must for OSI world but
10350                  * optional for Internet protocols) for all options.
10351                  * [ Will do only for the few options that enable test
10352                  * suites that our XTI implementation of this feature
10353                  * works for transports that do allow it ]
10354                  */
10355                 if (!tcp_allow_connopt_set(level, name)) {
10356                         *outlenp = 0;
10357                         return (EINVAL);
10358                 }
10359                 break;
10360         default:
10361                 /*
10362                  * We should never get here
10363                  */
10364                 *outlenp = 0;
10365                 return (EINVAL);
10366         }
10367 
10368         ASSERT((optset_context != SETFN_OPTCOM_CHECKONLY) ||
10369             (optset_context == SETFN_OPTCOM_CHECKONLY && inlen != 0));
10370 
10371         /*
10372          * For TCP, we should have no ancillary data sent down
10373          * (sendmsg isn't supported for SOCK_STREAM), so thisdg_attrs
10374          * has to be zero.
10375          */
10376         ASSERT(thisdg_attrs == NULL);
10377 
10378         /*
10379          * For fixed length options, no sanity check
10380          * of passed in length is done. It is assumed *_optcom_req()
10381          * routines do the right thing.
10382          */
10383 
10384         switch (level) {
10385         case SOL_SOCKET:
10386                 switch (name) {
10387                 case SO_LINGER: {
10388                         struct linger *lgr = (struct linger *)invalp;
10389 
10390                         if (!checkonly) {
10391                                 if (lgr->l_onoff) {
10392                                         tcp->tcp_linger = 1;
10393                                         tcp->tcp_lingertime = lgr->l_linger;
10394                                 } else {
10395                                         tcp->tcp_linger = 0;
10396                                         tcp->tcp_lingertime = 0;
10397                                 }
10398                                 /* struct copy */
10399                                 *(struct linger *)outvalp = *lgr;
10400                         } else {
10401                                 if (!lgr->l_onoff) {
10402                                         ((struct linger *)
10403                                             outvalp)->l_onoff = 0;
10404                                         ((struct linger *)
10405                                             outvalp)->l_linger = 0;
10406                                 } else {
10407                                         /* struct copy */
10408                                         *(struct linger *)outvalp = *lgr;
10409                                 }
10410                         }
10411                         *outlenp = sizeof (struct linger);
10412                         return (0);
10413                 }
10414                 case SO_DEBUG:
10415                         if (!checkonly)
10416                                 tcp->tcp_debug = onoff;
10417                         break;
10418                 case SO_KEEPALIVE:
10419                         if (checkonly) {
10420                                 /* T_CHECK case */
10421                                 break;
10422                         }
10423 
10424                         if (!onoff) {
10425                                 if (tcp->tcp_ka_enabled) {
10426                                         if (tcp->tcp_ka_tid != 0) {
10427                                                 (void) TCP_TIMER_CANCEL(tcp,
10428                                                     tcp->tcp_ka_tid);
10429                                                 tcp->tcp_ka_tid = 0;
10430                                         }
10431                                         tcp->tcp_ka_enabled = 0;
10432                                 }
10433                                 break;
10434                         }
10435                         if (!tcp->tcp_ka_enabled) {
10436                                 /* Crank up the keepalive timer */
10437                                 tcp->tcp_ka_last_intrvl = 0;
10438                                 tcp->tcp_ka_tid = TCP_TIMER(tcp,
10439                                     tcp_keepalive_killer,
10440                                     MSEC_TO_TICK(tcp->tcp_ka_interval));
10441                                 tcp->tcp_ka_enabled = 1;
10442                         }
10443                         break;
10444                 case SO_DONTROUTE:
10445                         /*
10446                          * SO_DONTROUTE, SO_USELOOPBACK, and SO_BROADCAST are
10447                          * only of interest to IP.  We track them here only so
10448                          * that we can report their current value.
10449                          */
10450                         if (!checkonly) {
10451                                 tcp->tcp_dontroute = onoff;
10452                                 tcp->tcp_connp->conn_dontroute = onoff;
10453                         }
10454                         break;
10455                 case SO_USELOOPBACK:
10456                         if (!checkonly) {
10457                                 tcp->tcp_useloopback = onoff;
10458                                 tcp->tcp_connp->conn_loopback = onoff;
10459                         }
10460                         break;
10461                 case SO_BROADCAST:
10462                         if (!checkonly) {
10463                                 tcp->tcp_broadcast = onoff;
10464                                 tcp->tcp_connp->conn_broadcast = onoff;
10465                         }
10466                         break;
10467                 case SO_REUSEADDR:
10468                         if (!checkonly) {
10469                                 tcp->tcp_reuseaddr = onoff;
10470                                 tcp->tcp_connp->conn_reuseaddr = onoff;
10471                         }
10472                         break;
10473                 case SO_OOBINLINE:
10474                         if (!checkonly)
10475                                 tcp->tcp_oobinline = onoff;
10476                         break;
10477                 case SO_DGRAM_ERRIND:
10478                         if (!checkonly)
10479                                 tcp->tcp_dgram_errind = onoff;
10480                         break;
10481                 case SO_SNDBUF: {
10482                         if (*i1 > tcps->tcps_max_buf) {
10483                                 *outlenp = 0;
10484                                 return (ENOBUFS);
10485                         }
10486                         if (checkonly)
10487                                 break;
10488 
10489                         tcp->tcp_xmit_hiwater = *i1;
10490                         if (tcps->tcps_snd_lowat_fraction != 0)
10491                                 tcp->tcp_xmit_lowater =
10492                                     tcp->tcp_xmit_hiwater /
10493                                     tcps->tcps_snd_lowat_fraction;
10494                         (void) tcp_maxpsz_set(tcp, B_TRUE);
10495                         /*
10496                          * If we are flow-controlled, recheck the condition.
10497                          * There are apps that increase SO_SNDBUF size when
10498                          * flow-controlled (EWOULDBLOCK), and expect the flow
10499                          * control condition to be lifted right away.
10500                          */
10501                         mutex_enter(&tcp->tcp_non_sq_lock);
10502                         if (tcp->tcp_flow_stopped &&
10503                             TCP_UNSENT_BYTES(tcp) < tcp->tcp_xmit_hiwater) {
10504                                 tcp_clrqfull(tcp);
10505                         }
10506                         mutex_exit(&tcp->tcp_non_sq_lock);
10507                         break;
10508                 }
10509                 case SO_RCVBUF:
10510                         if (*i1 > tcps->tcps_max_buf) {
10511                                 *outlenp = 0;
10512                                 return (ENOBUFS);
10513                         }
10514                         /* Silently ignore zero */
10515                         if (!checkonly && *i1 != 0) {
10516                                 *i1 = MSS_ROUNDUP(*i1, tcp->tcp_mss);
10517                                 (void) tcp_rwnd_set(tcp, *i1);
10518                         }
10519                         /*
10520                          * XXX should we return the rwnd here
10521                          * and tcp_opt_get ?
10522                          */
10523                         break;
10524                 case SO_SND_COPYAVOID:
10525                         if (!checkonly) {
10526                                 /* we only allow enable at most once for now */
10527                                 if (tcp->tcp_loopback ||
10528                                     (tcp->tcp_kssl_ctx != NULL) ||
10529                                     (!tcp->tcp_snd_zcopy_aware &&
10530                                     (onoff != 1 || !tcp_zcopy_check(tcp)))) {
10531                                         *outlenp = 0;
10532                                         return (EOPNOTSUPP);
10533                                 }
10534                                 tcp->tcp_snd_zcopy_aware = 1;
10535                         }
10536                         break;
10537                 case SO_ALLZONES:
10538                         /* Pass option along to IP level for handling */
10539                         return (-EINVAL);
10540                 case SO_ANON_MLP:
10541                         /* Pass option along to IP level for handling */
10542                         return (-EINVAL);
10543                 case SO_MAC_EXEMPT:
10544                         /* Pass option along to IP level for handling */
10545                         return (-EINVAL);
10546                 case SO_EXCLBIND:
10547                         if (!checkonly)
10548                                 tcp->tcp_exclbind = onoff;
10549                         break;
10550                 default:
10551                         *outlenp = 0;
10552                         return (EINVAL);
10553                 }
10554                 break;
10555         case IPPROTO_TCP:
10556                 switch (name) {
10557                 case TCP_NODELAY:
10558                         if (!checkonly)
10559                                 tcp->tcp_naglim = *i1 ? 1 : tcp->tcp_mss;
10560                         break;
10561                 case TCP_NOTIFY_THRESHOLD:
10562                         if (!checkonly)
10563                                 tcp->tcp_first_timer_threshold = *i1;
10564                         break;
10565                 case TCP_ABORT_THRESHOLD:
10566                         if (!checkonly)
10567                                 tcp->tcp_second_timer_threshold = *i1;
10568                         break;
10569                 case TCP_CONN_NOTIFY_THRESHOLD:
10570                         if (!checkonly)
10571                                 tcp->tcp_first_ctimer_threshold = *i1;
10572                         break;
10573                 case TCP_CONN_ABORT_THRESHOLD:
10574                         if (!checkonly)
10575                                 tcp->tcp_second_ctimer_threshold = *i1;
10576                         break;
10577                 case TCP_RECVDSTADDR:
10578                         if (tcp->tcp_state > TCPS_LISTEN)
10579                                 return (EOPNOTSUPP);
10580                         if (!checkonly)
10581                                 tcp->tcp_recvdstaddr = onoff;
10582                         break;
10583                 case TCP_ANONPRIVBIND:
10584                         if ((reterr = secpolicy_net_privaddr(cr, 0,
10585                             IPPROTO_TCP)) != 0) {
10586                                 *outlenp = 0;
10587                                 return (reterr);
10588                         }
10589                         if (!checkonly) {
10590                                 tcp->tcp_anon_priv_bind = onoff;
10591                         }
10592                         break;
10593                 case TCP_EXCLBIND:
10594                         if (!checkonly)
10595                                 tcp->tcp_exclbind = onoff;
10596                         break;  /* goto sizeof (int) option return */
10597                 case TCP_INIT_CWND: {
10598                         uint32_t init_cwnd = *((uint32_t *)invalp);
10599 
10600                         if (checkonly)
10601                                 break;
10602 
10603                         /*
10604                          * Only allow socket with network configuration
10605                          * privilege to set the initial cwnd to be larger
10606                          * than allowed by RFC 3390.
10607                          */
10608                         if (init_cwnd <= MIN(4, MAX(2, 4380 / tcp->tcp_mss))) {
10609                                 tcp->tcp_init_cwnd = init_cwnd;
10610                                 break;
10611                         }
10612                         if ((reterr = secpolicy_ip_config(cr, B_TRUE)) != 0) {
10613                                 *outlenp = 0;
10614                                 return (reterr);
10615                         }
10616                         if (init_cwnd > TCP_MAX_INIT_CWND) {
10617                                 *outlenp = 0;
10618                                 return (EINVAL);
10619                         }
10620                         tcp->tcp_init_cwnd = init_cwnd;
10621                         break;
10622                 }
10623                 case TCP_KEEPALIVE_THRESHOLD:
10624                         if (checkonly)
10625                                 break;
10626 
10627                         if (*i1 < tcps->tcps_keepalive_interval_low ||
10628                             *i1 > tcps->tcps_keepalive_interval_high) {
10629                                 *outlenp = 0;
10630                                 return (EINVAL);
10631                         }
10632                         if (*i1 != tcp->tcp_ka_interval) {
10633                                 tcp->tcp_ka_interval = *i1;
10634                                 /*
10635                                  * Check if we need to restart the
10636                                  * keepalive timer.
10637                                  */
10638                                 if (tcp->tcp_ka_tid != 0) {
10639                                         ASSERT(tcp->tcp_ka_enabled);
10640                                         (void) TCP_TIMER_CANCEL(tcp,
10641                                             tcp->tcp_ka_tid);
10642                                         tcp->tcp_ka_last_intrvl = 0;
10643                                         tcp->tcp_ka_tid = TCP_TIMER(tcp,
10644                                             tcp_keepalive_killer,
10645                                             MSEC_TO_TICK(tcp->tcp_ka_interval));
10646                                 }
10647                         }
10648                         break;
10649                 case TCP_KEEPALIVE_ABORT_THRESHOLD:
10650                         if (!checkonly) {
10651                                 if (*i1 <
10652                                     tcps->tcps_keepalive_abort_interval_low ||
10653                                     *i1 >
10654                                     tcps->tcps_keepalive_abort_interval_high) {
10655                                         *outlenp = 0;
10656                                         return (EINVAL);
10657                                 }
10658                                 tcp->tcp_ka_abort_thres = *i1;
10659                         }
10660                         break;
10661                 case TCP_CORK:
10662                         if (!checkonly) {
10663                                 /*
10664                                  * if tcp->tcp_cork was set and is now
10665                                  * being unset, we have to make sure that
10666                                  * the remaining data gets sent out. Also
10667                                  * unset tcp->tcp_cork so that tcp_wput_data()
10668                                  * can send data even if it is less than mss
10669                                  */
10670                                 if (tcp->tcp_cork && onoff == 0 &&
10671                                     tcp->tcp_unsent > 0) {
10672                                         tcp->tcp_cork = B_FALSE;
10673                                         tcp_wput_data(tcp, NULL, B_FALSE);
10674                                 }
10675                                 tcp->tcp_cork = onoff;
10676                         }
10677                         break;
10678                 default:
10679                         *outlenp = 0;
10680                         return (EINVAL);
10681                 }
10682                 break;
10683         case IPPROTO_IP:
10684                 if (tcp->tcp_family != AF_INET) {
10685                         *outlenp = 0;
10686                         return (ENOPROTOOPT);
10687                 }
10688                 switch (name) {
10689                 case IP_OPTIONS:
10690                 case T_IP_OPTIONS:
10691                         reterr = tcp_opt_set_header(tcp, checkonly,
10692                             invalp, inlen);
10693                         if (reterr) {
10694                                 *outlenp = 0;
10695                                 return (reterr);
10696                         }
10697                         /* OK return - copy input buffer into output buffer */
10698                         if (invalp != outvalp) {
10699                                 /* don't trust bcopy for identical src/dst */
10700                                 bcopy(invalp, outvalp, inlen);
10701                         }
10702                         *outlenp = inlen;
10703                         return (0);
10704                 case IP_TOS:
10705                 case T_IP_TOS:
10706                         if (!checkonly) {
10707                                 tcp->tcp_ipha->ipha_type_of_service =
10708                                     (uchar_t)*i1;
10709                                 tcp->tcp_tos = (uchar_t)*i1;
10710                         }
10711                         break;
10712                 case IP_TTL:
10713                         if (!checkonly) {
10714                                 tcp->tcp_ipha->ipha_ttl = (uchar_t)*i1;
10715                                 tcp->tcp_ttl = (uchar_t)*i1;
10716                         }
10717                         break;
10718                 case IP_BOUND_IF:
10719                 case IP_NEXTHOP:
10720                         /* Handled at the IP level */
10721                         return (-EINVAL);
10722                 case IP_SEC_OPT:
10723                         /*
10724                          * We should not allow policy setting after
10725                          * we start listening for connections.
10726                          */
10727                         if (tcp->tcp_state == TCPS_LISTEN) {
10728                                 return (EINVAL);
10729                         } else {
10730                                 /* Handled at the IP level */
10731                                 return (-EINVAL);
10732                         }
10733                 default:
10734                         *outlenp = 0;
10735                         return (EINVAL);
10736                 }
10737                 break;
10738         case IPPROTO_IPV6: {
10739                 ip6_pkt_t               *ipp;
10740 
10741                 /*
10742                  * IPPROTO_IPV6 options are only supported for sockets
10743                  * that are using IPv6 on the wire.
10744                  */
10745                 if (tcp->tcp_ipversion != IPV6_VERSION) {
10746                         *outlenp = 0;
10747                         return (ENOPROTOOPT);
10748                 }
10749                 /*
10750                  * Only sticky options; no ancillary data
10751                  */
10752                 ASSERT(thisdg_attrs == NULL);
10753                 ipp = &tcp->tcp_sticky_ipp;
10754 
10755                 switch (name) {
10756                 case IPV6_UNICAST_HOPS:
10757                         /* -1 means use default */
10758                         if (*i1 < -1 || *i1 > IPV6_MAX_HOPS) {
10759                                 *outlenp = 0;
10760                                 return (EINVAL);
10761                         }
10762                         if (!checkonly) {
10763                                 if (*i1 == -1) {
10764                                         tcp->tcp_ip6h->ip6_hops =
10765                                             ipp->ipp_unicast_hops =
10766                                             (uint8_t)tcps->tcps_ipv6_hoplimit;
10767                                         ipp->ipp_fields &= ~IPPF_UNICAST_HOPS;
10768                                         /* Pass modified value to IP. */
10769                                         *i1 = tcp->tcp_ip6h->ip6_hops;
10770                                 } else {
10771                                         tcp->tcp_ip6h->ip6_hops =
10772                                             ipp->ipp_unicast_hops =
10773                                             (uint8_t)*i1;
10774                                         ipp->ipp_fields |= IPPF_UNICAST_HOPS;
10775                                 }
10776                                 reterr = tcp_build_hdrs(q, tcp);
10777                                 if (reterr != 0)
10778                                         return (reterr);
10779                         }
10780                         break;
10781                 case IPV6_BOUND_IF:
10782                         if (!checkonly) {
10783                                 int error = 0;
10784 
10785                                 tcp->tcp_bound_if = *i1;
10786                                 error = ip_opt_set_ill(tcp->tcp_connp, *i1,
10787                                     B_TRUE, checkonly, level, name, mblk);
10788                                 if (error != 0) {
10789                                         *outlenp = 0;
10790                                         return (error);
10791                                 }
10792                         }
10793                         break;
10794                 /*
10795                  * Set boolean switches for ancillary data delivery
10796                  */
10797                 case IPV6_RECVPKTINFO:
10798                         if (!checkonly) {
10799                                 if (onoff)
10800                                         tcp->tcp_ipv6_recvancillary |=
10801                                             TCP_IPV6_RECVPKTINFO;
10802                                 else
10803                                         tcp->tcp_ipv6_recvancillary &=
10804                                             ~TCP_IPV6_RECVPKTINFO;
10805                                 /* Force it to be sent up with the next msg */
10806                                 tcp->tcp_recvifindex = 0;
10807                         }
10808                         break;
10809                 case IPV6_RECVTCLASS:
10810                         if (!checkonly) {
10811                                 if (onoff)
10812                                         tcp->tcp_ipv6_recvancillary |=
10813                                             TCP_IPV6_RECVTCLASS;
10814                                 else
10815                                         tcp->tcp_ipv6_recvancillary &=
10816                                             ~TCP_IPV6_RECVTCLASS;
10817                         }
10818                         break;
10819                 case IPV6_RECVHOPLIMIT:
10820                         if (!checkonly) {
10821                                 if (onoff)
10822                                         tcp->tcp_ipv6_recvancillary |=
10823                                             TCP_IPV6_RECVHOPLIMIT;
10824                                 else
10825                                         tcp->tcp_ipv6_recvancillary &=
10826                                             ~TCP_IPV6_RECVHOPLIMIT;
10827                                 /* Force it to be sent up with the next msg */
10828                                 tcp->tcp_recvhops = 0xffffffffU;
10829                         }
10830                         break;
10831                 case IPV6_RECVHOPOPTS:
10832                         if (!checkonly) {
10833                                 if (onoff)
10834                                         tcp->tcp_ipv6_recvancillary |=
10835                                             TCP_IPV6_RECVHOPOPTS;
10836                                 else
10837                                         tcp->tcp_ipv6_recvancillary &=
10838                                             ~TCP_IPV6_RECVHOPOPTS;
10839                         }
10840                         break;
10841                 case IPV6_RECVDSTOPTS:
10842                         if (!checkonly) {
10843                                 if (onoff)
10844                                         tcp->tcp_ipv6_recvancillary |=
10845                                             TCP_IPV6_RECVDSTOPTS;
10846                                 else
10847                                         tcp->tcp_ipv6_recvancillary &=
10848                                             ~TCP_IPV6_RECVDSTOPTS;
10849                         }
10850                         break;
10851                 case _OLD_IPV6_RECVDSTOPTS:
10852                         if (!checkonly) {
10853                                 if (onoff)
10854                                         tcp->tcp_ipv6_recvancillary |=
10855                                             TCP_OLD_IPV6_RECVDSTOPTS;
10856                                 else
10857                                         tcp->tcp_ipv6_recvancillary &=
10858                                             ~TCP_OLD_IPV6_RECVDSTOPTS;
10859                         }
10860                         break;
10861                 case IPV6_RECVRTHDR:
10862                         if (!checkonly) {
10863                                 if (onoff)
10864                                         tcp->tcp_ipv6_recvancillary |=
10865                                             TCP_IPV6_RECVRTHDR;
10866                                 else
10867                                         tcp->tcp_ipv6_recvancillary &=
10868                                             ~TCP_IPV6_RECVRTHDR;
10869                         }
10870                         break;
10871                 case IPV6_RECVRTHDRDSTOPTS:
10872                         if (!checkonly) {
10873                                 if (onoff)
10874                                         tcp->tcp_ipv6_recvancillary |=
10875                                             TCP_IPV6_RECVRTDSTOPTS;
10876                                 else
10877                                         tcp->tcp_ipv6_recvancillary &=
10878                                             ~TCP_IPV6_RECVRTDSTOPTS;
10879                         }
10880                         break;
10881                 case IPV6_PKTINFO:
10882                         if (inlen != 0 && inlen != sizeof (struct in6_pktinfo))
10883                                 return (EINVAL);
10884                         if (checkonly)
10885                                 break;
10886 
10887                         if (inlen == 0) {
10888                                 ipp->ipp_fields &= ~(IPPF_IFINDEX|IPPF_ADDR);
10889                         } else {
10890                                 struct in6_pktinfo *pkti;
10891 
10892                                 pkti = (struct in6_pktinfo *)invalp;
10893                                 /*
10894                                  * RFC 3542 states that ipi6_addr must be
10895                                  * the unspecified address when setting the
10896                                  * IPV6_PKTINFO sticky socket option on a
10897                                  * TCP socket.
10898                                  */
10899                                 if (!IN6_IS_ADDR_UNSPECIFIED(&pkti->ipi6_addr))
10900                                         return (EINVAL);
10901                                 /*
10902                                  * ip6_set_pktinfo() validates the source
10903                                  * address and interface index.
10904                                  */
10905                                 reterr = ip6_set_pktinfo(cr, tcp->tcp_connp,
10906                                     pkti, mblk);
10907                                 if (reterr != 0)
10908                                         return (reterr);
10909                                 ipp->ipp_ifindex = pkti->ipi6_ifindex;
10910                                 ipp->ipp_addr = pkti->ipi6_addr;
10911                                 if (ipp->ipp_ifindex != 0)
10912                                         ipp->ipp_fields |= IPPF_IFINDEX;
10913                                 else
10914                                         ipp->ipp_fields &= ~IPPF_IFINDEX;
10915                                 if (!IN6_IS_ADDR_UNSPECIFIED(&ipp->ipp_addr))
10916                                         ipp->ipp_fields |= IPPF_ADDR;
10917                                 else
10918                                         ipp->ipp_fields &= ~IPPF_ADDR;
10919                         }
10920                         reterr = tcp_build_hdrs(q, tcp);
10921                         if (reterr != 0)
10922                                 return (reterr);
10923                         break;
10924                 case IPV6_TCLASS:
10925                         if (inlen != 0 && inlen != sizeof (int))
10926                                 return (EINVAL);
10927                         if (checkonly)
10928                                 break;
10929 
10930                         if (inlen == 0) {
10931                                 ipp->ipp_fields &= ~IPPF_TCLASS;
10932                         } else {
10933                                 if (*i1 > 255 || *i1 < -1)
10934                                         return (EINVAL);
10935                                 if (*i1 == -1) {
10936                                         ipp->ipp_tclass = 0;
10937                                         *i1 = 0;
10938                                 } else {
10939                                         ipp->ipp_tclass = *i1;
10940                                 }
10941                                 ipp->ipp_fields |= IPPF_TCLASS;
10942                         }
10943                         reterr = tcp_build_hdrs(q, tcp);
10944                         if (reterr != 0)
10945                                 return (reterr);
10946                         break;
10947                 case IPV6_NEXTHOP:
10948                         /*
10949                          * IP will verify that the nexthop is reachable
10950                          * and fail for sticky options.
10951                          */
10952                         if (inlen != 0 && inlen != sizeof (sin6_t))
10953                                 return (EINVAL);
10954                         if (checkonly)
10955                                 break;
10956 
10957                         if (inlen == 0) {
10958                                 ipp->ipp_fields &= ~IPPF_NEXTHOP;
10959                         } else {
10960                                 sin6_t *sin6 = (sin6_t *)invalp;
10961 
10962                                 if (sin6->sin6_family != AF_INET6)
10963                                         return (EAFNOSUPPORT);
10964                                 if (IN6_IS_ADDR_V4MAPPED(
10965                                     &sin6->sin6_addr))
10966                                         return (EADDRNOTAVAIL);
10967                                 ipp->ipp_nexthop = sin6->sin6_addr;
10968                                 if (!IN6_IS_ADDR_UNSPECIFIED(
10969                                     &ipp->ipp_nexthop))
10970                                         ipp->ipp_fields |= IPPF_NEXTHOP;
10971                                 else
10972                                         ipp->ipp_fields &= ~IPPF_NEXTHOP;
10973                         }
10974                         reterr = tcp_build_hdrs(q, tcp);
10975                         if (reterr != 0)
10976                                 return (reterr);
10977                         break;
10978                 case IPV6_HOPOPTS: {
10979                         ip6_hbh_t *hopts = (ip6_hbh_t *)invalp;
10980 
10981                         /*
10982                          * Sanity checks - minimum size, size a multiple of
10983                          * eight bytes, and matching size passed in.
10984                          */
10985                         if (inlen != 0 &&
10986                             inlen != (8 * (hopts->ip6h_len + 1)))
10987                                 return (EINVAL);
10988 
10989                         if (checkonly)
10990