--- old/usr/src/cmd/fs.d/nfs/nfsd/nfsd.c	Wed Jun 17 00:15:44 2009
+++ new/usr/src/cmd/fs.d/nfs/nfsd/nfsd.c	Wed Jun 17 00:15:43 2009
@@ -128,6 +128,19 @@
  */
 int	nfs_server_delegation = NFS_SERVER_DELEGATION_DEFAULT;
 
+/*
+ * Default values for TCP send and receive buffer size of NFS server
+ * connections.
+ *
+ * These values can be tuned by user via /etc/default/nfs configuration
+ * file by setting NFS_SERVER_SNDBUFSZ and NFS_SERVER_RCVBUFSZ.
+ *
+ * To force NFS connections to use system-wide default for TCP send and
+ * receive buffer, set NFS_SERVER_SNDBUFSZ and NFS_SERVER_RCVBUFSZ to 0.
+ */
+int	nfs_server_sndbufsz = 1048576;
+int	nfs_server_rcvbufsz = 1048576;
+
 int
 main(int ac, char *av[])
 {
@@ -139,7 +152,7 @@
 	int maxservers_set = 0;
 	int logmaxservers = 0;
 	int pid;
-	int i;
+	int i, bufsz;
 	char *provider = (char *)NULL;
 	char *df_provider = (char *)NULL;
 	struct protob *protobp0, *protobp;
@@ -235,6 +248,18 @@
 				nfs_server_delegation = FALSE;
 			}
 		}
+		if ((defval = defread("NFS_SERVER_SNDBUFSZ=")) != NULL) {
+			errno = 0;
+			bufsz = strtol(defval, (char **)NULL, 10);
+			if (errno == 0)
+				nfs_server_sndbufsz = bufsz;
+		}
+		if ((defval = defread("NFS_SERVER_RCVBUFSZ=")) != NULL) {
+			errno = 0;
+			bufsz = strtol(defval, (char **)NULL, 10);
+			if (errno == 0)
+				nfs_server_rcvbufsz = bufsz;
+		}
 
 		/* close defaults file */
 		defopen(NULL);
@@ -534,7 +559,8 @@
 	protobp->next = (struct protob *)NULL;
 
 	if (allflag) {
-		if (do_all(protobp0, nfssvc, 0) == -1) {
+		if (do_all_setbuf(protobp0, nfssvc, 0, nfs_server_sndbufsz,
+		    nfs_server_rcvbufsz) == -1) {
 			fprintf(stderr, "setnetconfig failed : %s",
 			    strerror(errno));
 			exit(1);
@@ -552,8 +578,9 @@
 		while (nconf = getnetconfig(nc)) {
 			if (strcmp(nconf->nc_proto, proto) == 0) {
 				protoFound = TRUE;
-				do_one(nconf->nc_device, NULL,
-				    protobp0, nfssvc, 0);
+				do_one_setbuf(nconf->nc_device, NULL,
+				    protobp0, nfssvc, 0,
+				    nfs_server_sndbufsz, nfs_server_rcvbufsz);
 			}
 		}
 		(void) endnetconfig(nc);
@@ -563,12 +590,14 @@
 			    proto);
 		}
 	} else if (provider)
-		do_one(provider, proto, protobp0, nfssvc, 0);
+		do_one_setbuf(provider, proto, protobp0, nfssvc, 0,
+		    nfs_server_sndbufsz, nfs_server_rcvbufsz);
 	else {
 		for (providerp = defaultproviders;
 		    *providerp != NULL; providerp++) {
 			provider = *providerp;
-			do_one(provider, NULL, protobp0, nfssvc, 0);
+			do_one_setbuf(provider, NULL, protobp0, nfssvc, 0,
+			    nfs_server_sndbufsz, nfs_server_rcvbufsz);
 		}
 	}
 done: