917 Make TCP's iss_incr a tunable

@@ -18,10 +18,11 @@
  *
  * CDDL HEADER END
  */
 /*
  * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, Joyent Inc. All rights reserved.
  */
 /* Copyright (c) 1990 Mentat Inc. */
 
 #include <inet/ip.h>
 #include <inet/tcp_impl.h>

@@ -470,10 +471,15 @@
             tcp_listener_conf_add, NULL, {0}, {0} },
 
         { "_listener_limit_conf_del", MOD_PROTO_TCP,
             tcp_listener_conf_del, NULL, {0}, {0} },
 
+        { "_iss_incr", MOD_PROTO_TCP,
+            mod_set_uint32, mod_get_uint32,
+            {1, ISS_INCR, ISS_INCR},
+            {ISS_INCR} },
+
         { "?", MOD_PROTO_TCP, NULL, mod_get_allprop, {0}, {0} },
 
         { NULL, 0, NULL, NULL, {0}, {0} }
 };