Commit ea4f76ae authored Nov 30, 2007 by Ilpo Järvinen Committed by David S. Miller Jan 28, 2008

[TCP]: Two fixes to new sacktag code



1) Skip condition used to be wrong way around which made SACK
processing very broken, missed many blocks because of that.

2) Use highest_sack advancement only if some skbs are already
sacked because otherwise tcp_write_queue_next may move things
too far (occurs mainly with GSO). The other similar advancement
is not problem because highest_sack was previosly put to point
a sacked skb.

These problems were located because of problem report from Matt
Mathis <mathis@psc.edu>.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent df1b86c5

net/ipv4/tcp_input.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1384,7 +1384,7 @@ static struct sk_buff tcp_sacktag_skip(struct sk_buff skb, struct sock *sk,
		if (skb == tcp_send_head(sk))
		break;

		if (before(TCP_SKB_CB(skb)->end_seq, skip_to_seq))
		if (!before(TCP_SKB_CB(skb)->end_seq, skip_to_seq))
		break;
		}
		return skb;
		@@ -1575,7 +1575,7 @@ tcp_sacktag_write_queue(struct sock sk, struct sk_buff ack_skb, u32 prior_snd_
		continue;
		}

		if (!before(start_seq, tcp_highest_sack_seq(tp))) {
		if (tp->sacked_out && !before(start_seq, tcp_highest_sack_seq(tp))) {
		skb = tcp_write_queue_next(sk, tp->highest_sack);
		fack_count = tp->fackets_out;
		}