svn commit: r232341 - user/andre/tcp_workqueue/sys/netinet

[Andre Oppermann]

Author: andre
Date: Thu Mar  1 15:08:58 2012
New Revision: 232341
URL: http://svn.freebsd.org/changeset/base/232341

Log:
  Adjust the default initial CWND upon connection establishment to the
  new and larger values specified by RFC5681 Section 3.1.
  
  The larger initial CWND per RFC3390, if enabled, is not affected.

Modified:
  user/andre/tcp_workqueue/sys/netinet/tcp_input.c

Modified: user/andre/tcp_workqueue/sys/netinet/tcp_input.c
==============================================================================
--- user/andre/tcp_workqueue/sys/netinet/tcp_input.c	Thu Mar  1 14:42:06 2012	(r232340)
+++ user/andre/tcp_workqueue/sys/netinet/tcp_input.c	Thu Mar  1 15:08:58 2012	(r232341)
@@ -347,8 +347,15 @@ cc_conn_init(struct tcpcb *tp)
 	if (V_tcp_do_rfc3390)
 		tp->snd_cwnd = min(4 * tp->t_maxseg,
 		    max(2 * tp->t_maxseg, 4380));
-	else
-		tp->snd_cwnd = tp->t_maxseg;
+	else {
+		/* Per RFC5681 Section 3.1 */
+		if (tp->t_maxseg > 2190)
+			tp->snd_cwnd = 2 * tp->t_maxseg;
+		if (tp->t_maxseg > 1095)
+			tp->snd_cwnd = 3 * tp->t_maxseg;
+		else
+			tp->snd_cwnd = 4 * tp->t_maxseg;
+	}
 
 	if (CC_ALGO(tp)->conn_init != NULL)
 		CC_ALGO(tp)->conn_init(tp->ccv);