From 580e572a4a1bfea2f42af63ba4785ac7dfbcb45d Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ilpo=20J=C3=A4rvinen?= Date: Sat, 19 May 2007 13:56:57 -0700 Subject: [PATCH] [TCP] FRTO: Prevent state inconsistency in corner cases MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit State could become inconsistent in two cases: 1) Userspace disabled FRTO by tuning sysctl when one of the TCP flows was in the middle of FRTO algorithm (and then RTO is again triggered) 2) SACK reneging occurs during FRTO algorithm A simple solution is just to abort the previous FRTO when such obscure condition occurs... Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 7ecdc89..38cb25b 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1501,6 +1501,8 @@ void tcp_enter_loss(struct sock *sk, int how) tcp_set_ca_state(sk, TCP_CA_Loss); tp->high_seq = tp->snd_nxt; TCP_ECN_queue_cwr(tp); + /* Abort FRTO algorithm if one is in progress */ + tp->frto_counter = 0; clear_all_retrans_hints(tp); } -- 2.7.4