From: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Date: Wed, 18 Jul 2007 09:30:41 +0000 (-0700)
Subject: TCP FRTO retransmit bug fix
X-Git-Tag: v2.6.22.2~83
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2c92c72b750cb92566b7e6031f84bc9a35699e73;p=thirdparty%2Fkernel%2Fstable.git

TCP FRTO retransmit bug fix

[TCP]: Verify the presence of RETRANS bit when leaving FRTO

For yet unknown reason, something cleared SACKED_RETRANS bit
underneath FRTO.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 69f9f1ef3ef69..4e5884ac8f299 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1398,7 +1398,9 @@ static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
 		 * waiting for the first ACK and did not get it)...
 		 */
 		if ((tp->frto_counter == 1) && !(flag&FLAG_DATA_ACKED)) {
-			tp->retrans_out += tcp_skb_pcount(skb);
+			/* For some reason this R-bit might get cleared? */
+			if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)
+				tp->retrans_out += tcp_skb_pcount(skb);
 			/* ...enter this if branch just for the first segment */
 			flag |= FLAG_DATA_ACKED;
 		} else {