From 8872d8e1c4311dd7e5086975df9c76120a0be83b Mon Sep 17 00:00:00 2001 From: "Angelo P. Castellani" Date: Tue, 16 May 2006 21:42:11 -0700 Subject: [PATCH] [TCP]: reno sacked_out count fix From: "Angelo P. Castellani" Using NewReno, if a sk_buff is timed out and is accounted as lost_out, it should also be removed from the sacked_out. This is necessary because recovery using NewReno fast retransmit could take up to a lot RTTs and the sk_buff RTO can expire without actually being really lost. left_out = sacked_out + lost_out in_flight = packets_out - left_out + retrans_out Using NewReno without this patch, on very large network losses, left_out becames bigger than packets_out + retrans_out (!!). For this reason unsigned integer in_flight overflows to 2^32 - something. 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 9f0cca4c4fae..4a538bc1683d 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1662,6 +1662,8 @@ static void tcp_update_scoreboard(struct sock *sk, struct tcp_sock *tp) if (!(TCP_SKB_CB(skb)->sacked&TCPCB_TAGBITS)) { TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; tp->lost_out += tcp_skb_pcount(skb); + if (IsReno(tp)) + tcp_remove_reno_sacks(sk, tp, tcp_skb_pcount(skb) + 1); /* clear xmit_retrans hint */ if (tp->retransmit_skb_hint &&