[src/trunk]: src/sys/netinet Make sure that snd_win doesn't go negative.

[matt <matt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/50e70aa49e12
branches:  trunk
changeset: 339469:50e70aa49e12
user:      matt <matt%NetBSD.org@localhost>
date:      Fri Jul 24 04:31:20 2015 +0000

description:
Make sure that snd_win doesn't go negative.

diffstat:

 sys/netinet/tcp_input.c |  9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)

diffs (30 lines):

diff -r 876e4e42b40e -r 50e70aa49e12 sys/netinet/tcp_input.c
--- a/sys/netinet/tcp_input.c   Fri Jul 24 04:29:27 2015 +0000
+++ b/sys/netinet/tcp_input.c   Fri Jul 24 04:31:20 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tcp_input.c,v 1.342 2015/07/15 09:20:18 ozaki-r Exp $  */
+/*     $NetBSD: tcp_input.c,v 1.343 2015/07/24 04:31:20 matt Exp $     */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -148,7 +148,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tcp_input.c,v 1.342 2015/07/15 09:20:18 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tcp_input.c,v 1.343 2015/07/24 04:31:20 matt Exp $");
 
 #include "opt_inet.h"
 #include "opt_ipsec.h"
@@ -2713,7 +2713,10 @@
                                tp->t_lastm = NULL;
                        sbdrop(&so->so_snd, acked);
                        tp->t_lastoff -= acked;
-                       tp->snd_wnd -= acked;
+                       if (tp->snd_wnd > acked)
+                               tp->snd_wnd -= acked;
+                       else
+                               tp->snd_wnd = 0;
                        ourfinisacked = 0;
                }
                sowwakeup(so);