From 6a2257d9111ee31d0dcf0d6cc5fe4ebe682bbc1a Mon Sep 17 00:00:00 2001
From: Andre Oppermann <andre@FreeBSD.org>
Date: Thu, 28 Sep 2006 13:59:26 +0000
Subject: [PATCH] When doing TSO correctly do the check to prevent a maximum
 sized IP packet from overflowing.

---
 sys/netinet/tcp_output.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
index dc67a5d65ef..0ea53e283f8 100644
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -739,7 +739,7 @@ send:
 	if (len + optlen + ipoptlen > tp->t_maxopd) {
 		flags &= ~TH_FIN;
 		if (tso) {
-			if (len > TCP_MAXWIN) {
+			if (len > TCP_MAXWIN - hdrlen) {
 				len = TCP_MAXWIN - hdrlen;
 				len = len - (len % (tp->t_maxopd - optlen));
 				sendalot = 1;