From 7769f4064cd9f4fbae09f071578a051aae83e844 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ilpo=20J=C3=A4rvinen?= Date: Fri, 15 Jun 2007 15:14:04 -0700 Subject: [PATCH] [TCP]: Fix logic breakage due to DSACK separation MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Commit 6f74651ae626ec672028587bc700538076dfbefb is found guilty of breaking DSACK counting, which should be done only for the SACK block reported by the DSACK instead of every SACK block that is received along with DSACK information. Signed-off-by: Ilpo Järvinen Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index aaf6f66677f..69f9f1ef3ef 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -953,7 +953,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ int prior_fackets; u32 lost_retrans = 0; int flag = 0; - int dup_sack = 0; + int found_dup_sack = 0; int cached_fack_count; int i; int first_sack_index; @@ -964,20 +964,20 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ /* Check for D-SACK. */ if (before(ntohl(sp[0].start_seq), TCP_SKB_CB(ack_skb)->ack_seq)) { - dup_sack = 1; + found_dup_sack = 1; tp->rx_opt.sack_ok |= 4; NET_INC_STATS_BH(LINUX_MIB_TCPDSACKRECV); } else if (num_sacks > 1 && !after(ntohl(sp[0].end_seq), ntohl(sp[1].end_seq)) && !before(ntohl(sp[0].start_seq), ntohl(sp[1].start_seq))) { - dup_sack = 1; + found_dup_sack = 1; tp->rx_opt.sack_ok |= 4; NET_INC_STATS_BH(LINUX_MIB_TCPDSACKOFORECV); } /* D-SACK for already forgotten data... * Do dumb counting. */ - if (dup_sack && + if (found_dup_sack && !after(ntohl(sp[0].end_seq), prior_snd_una) && after(ntohl(sp[0].end_seq), tp->undo_marker)) tp->undo_retrans--; @@ -1058,6 +1058,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ __u32 start_seq = ntohl(sp->start_seq); __u32 end_seq = ntohl(sp->end_seq); int fack_count; + int dup_sack = (found_dup_sack && (i == first_sack_index)); skb = cached_skb; fack_count = cached_fack_count; -- 2.41.1