From: Eric Dumazet <edumazet@google.com>
Date: Tue, 10 May 2016 03:55:16 +0000 (-0700)
Subject: tcp: refresh skb timestamp at retransmit time
X-Git-Tag: v4.1.12-92~15^2~51
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=02b79654a0954c5ca3da688eadb8e5c84066ca8c;p=users%2Fjedix%2Flinux-maple.git

tcp: refresh skb timestamp at retransmit time

Orabug: 25308087

[ Upstream commit 10a81980fc47e64ffac26a073139813d3f697b64 ]

In the very unlikely case __tcp_retransmit_skb() can not use the cloning
done in tcp_transmit_skb(), we need to refresh skb_mstamp before doing
the copy and transmit, otherwise TCP TS val will be an exact copy of
original transmit.

Fixes: 7faee5c0d514 ("tcp: remove TCP_SKB_CB(skb)->when")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
(cherry picked from commit 90eb6718b9db5c145f7c2d4a14df6a4b8d96e7b3)
Signed-off-by: Dhaval Giani <dhaval.giani@oracle.com>
---

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 1ea4322c3b0c..ae66c8426ad0 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2627,8 +2627,10 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
 	 */
 	if (unlikely((NET_IP_ALIGN && ((unsigned long)skb->data & 3)) ||
 		     skb_headroom(skb) >= 0xFFFF)) {
-		struct sk_buff *nskb = __pskb_copy(skb, MAX_TCP_HEADER,
-						   GFP_ATOMIC);
+		struct sk_buff *nskb;
+
+		skb_mstamp_get(&skb->skb_mstamp);
+		nskb = __pskb_copy(skb, MAX_TCP_HEADER, GFP_ATOMIC);
 		err = nskb ? tcp_transmit_skb(sk, nskb, 0, GFP_ATOMIC) :
 			     -ENOBUFS;
 	} else {