Commit 580e572a authored May 19, 2007 by Ilpo Järvinen Committed by David S. Miller May 19, 2007

[TCP] FRTO: Prevent state inconsistency in corner cases



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

parent 46323655

net/ipv4/tcp_input.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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);
		}

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