From: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Date: Sat, 28 Feb 2009 04:44:31 +0000 (+0000)
Subject: tcp: fix corner case issue in segmentation during rexmitting
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=02276f3c962fd408fa9d441251067845f948bfcf;p=openwrt%2Fstaging%2Fblogic.git

tcp: fix corner case issue in segmentation during rexmitting

If cur_mss grew very recently so that the previously G/TSOed skb
now fits well into a single segment it would get send up in
parts unless we calculate # of segments again. This corner-case
could happen eg. after mtu probe completes or less than
previously sack blocks are required for the opposite direction.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 3feab4d6929d..77af7faf38a9 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1921,6 +1921,8 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 	if (skb->len > cur_mss) {
 		if (tcp_fragment(sk, skb, cur_mss, cur_mss))
 			return -ENOMEM; /* We'll try again later. */
+	} else {
+		tcp_init_tso_segs(sk, skb, cur_mss);
 	}
 
 	tcp_retrans_try_collapse(sk, skb, cur_mss);