[PATCH] tcp: set timestamps for restored skb-s

[PATCH] tcp: set timestamps for restored skb-s

[Andrey Vagin]

When the repair mode is turned off, the write queue seqs are
updated so that the whole queue is considered to be 'already sent.

The "when" field must be set for such skb. It's used in tcp_rearm_rto
for example. If the "when" field isn't set, the retransmit timeout can
be calculated incorrectly and a tcp connected can stop for two minutes
(TCP_RTO_MAX).

Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
---
 net/ipv4/tcp.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 5423223..b2f6c74 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1121,6 +1121,13 @@ new_segment:
 					goto wait_for_memory;
 
 				/*
+				 * All packets are restored as if they have
+				 * already been sent.
+				 */
+				if (tp->repair)
+					TCP_SKB_CB(skb)->when = tcp_time_stamp;
+
+				/*
 				 * Check whether we can use HW checksum.
 				 */
 				if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
-- 
1.8.3.1

Re: [PATCH] tcp: set timestamps for restored skb-s

[David Miller]

From: Andrey Vagin <avagin@openvz.org>
Date: Fri, 16 Aug 2013 19:04:36 +0400

> When the repair mode is turned off, the write queue seqs are
> updated so that the whole queue is considered to be 'already sent.
> 
> The "when" field must be set for such skb. It's used in tcp_rearm_rto
> for example. If the "when" field isn't set, the retransmit timeout can
> be calculated incorrectly and a tcp connected can stop for two minutes
> (TCP_RTO_MAX).
> 
> Acked-by: Pavel Emelyanov <xemul@parallels.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
> Cc: James Morris <jmorris@namei.org>
> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
> Cc: Patrick McHardy <kaber@trash.net>
> Signed-off-by: Andrey Vagin <avagin@openvz.org>

Applied and queued up for -stable, thanks.