From: Ilpo Järvinen Date: Wed, 14 Nov 2007 23:55:09 +0000 (-0800) Subject: [TCP] FRTO: Clear frto_highmark only after process_frto that uses it X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=e1cd8f78f8cbfa314a095dbf704707217c8ee197;p=deliverable%2Flinux.git [TCP] FRTO: Clear frto_highmark only after process_frto that uses it I broke this in commit 3de96471bd7fb76406e975ef6387abe3a0698149: [TCP]: Wrap-safed reordering detection FRTO check tcp_process_frto should always see a valid frto_highmark. An invalid frto_highmark (zero) is very likely what ultimately caused a seqno compare in tcp_frto_enter_loss to do the wrong leading to the LOST-bit leak. Having LOST-bits integry ensured like done after commit 23aeeec365dcf8bc87fae44c533e50d0bb4f23cc: [TCP] FRTO: Plug potential LOST-bit leak won't hurt. It may still be useful in some other, possibly legimate, scenario. Reported by Chazarain Guillaume . Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller --- diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 3f126ece8eb5..0f0c1c9829a1 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3113,11 +3113,11 @@ static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag) /* See if we can take anything off of the retransmit queue. */ flag |= tcp_clean_rtx_queue(sk, &seq_rtt, prior_fackets); + if (tp->frto_counter) + frto_cwnd = tcp_process_frto(sk, flag); /* Guarantee sacktag reordering detection against wrap-arounds */ if (before(tp->frto_highmark, tp->snd_una)) tp->frto_highmark = 0; - if (tp->frto_counter) - frto_cwnd = tcp_process_frto(sk, flag); if (tcp_ack_is_dubious(sk, flag)) { /* Advance CWND, if state allows this. */