diff options
| -rw-r--r-- | net/ipv4/tcp_input.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 69d8c38ccd39..4d72781a49be 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1330,12 +1330,15 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ cached_fack_count = 0; } - for (i=0; i<num_sacks; i++, sp++) { + for (i = 0; i < num_sacks; i++) { struct sk_buff *skb; __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)); + int next_dup = (found_dup_sack && (i+1 == first_sack_index)); + + sp++; if (!tcp_is_sackblock_valid(tp, dup_sack, start_seq, end_seq)) { if (dup_sack) { @@ -1361,7 +1364,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ flag |= FLAG_DATA_LOST; tcp_for_write_queue_from(skb, sk) { - int in_sack; + int in_sack = 0; u8 sacked; if (skb == tcp_send_head(sk)) @@ -1380,7 +1383,23 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ if (!before(TCP_SKB_CB(skb)->seq, end_seq)) break; - in_sack = tcp_match_skb_to_sack(sk, skb, start_seq, end_seq); + dup_sack = (found_dup_sack && (i == first_sack_index)); + + /* Due to sorting DSACK may reside within this SACK block! */ + if (next_dup) { + u32 dup_start = ntohl(sp->start_seq); + u32 dup_end = ntohl(sp->end_seq); + + if (before(TCP_SKB_CB(skb)->seq, dup_end)) { + in_sack = tcp_match_skb_to_sack(sk, skb, dup_start, dup_end); + if (in_sack > 0) + dup_sack = 1; + } + } + + /* DSACK info lost if out-of-mem, try SACK still */ + if (in_sack <= 0) + in_sack = tcp_match_skb_to_sack(sk, skb, start_seq, end_seq); if (in_sack < 0) break; |