Commit db3ccdac authored Jan 25, 2007 by Baruch Even Committed by David S. Miller Jan 25, 2007

[TCP]: Fix sorting of SACK blocks.



The sorting of SACK blocks actually munges them rather than sort,
causing the TCP stack to ignore some SACK information and breaking the
assumption of ordered SACK blocks after sorting.

The sort takes the data from a second buffer which isn't moved causing
subsequent data moves to occur from the wrong location. The fix is to
use a temporary buffer as a normal sort does.

Signed-off-By: Baruch Even <baruch@ev-en.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent dbcb5855

net/ipv4/tcp_input.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -1011,10 +1011,11 @@ tcp_sacktag_write_queue(struct sock sk, struct sk_buff ack_skb, u32 prior_snd_
		for (j = 0; j < i; j++){
		if (after(ntohl(sp[j].start_seq),
		ntohl(sp[j+1].start_seq))){
		sp[j].start_seq = htonl(tp->recv_sack_cache[j+1].start_seq);
		sp[j].end_seq = htonl(tp->recv_sack_cache[j+1].end_seq);
		sp[j+1].start_seq = htonl(tp->recv_sack_cache[j].start_seq);
		sp[j+1].end_seq = htonl(tp->recv_sack_cache[j].end_seq);
		struct tcp_sack_block_wire tmp;

		tmp = sp[j];
		sp[j] = sp[j+1];
		sp[j+1] = tmp;
		}

		}