diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_input.c | 66 |
1 files changed, 31 insertions, 35 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 7670ef968dce..870f53afd363 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -951,16 +951,43 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ tp->fackets_out = 0; prior_fackets = tp->fackets_out; + /* Check for D-SACK. */ + if (before(ntohl(sp[0].start_seq), TCP_SKB_CB(ack_skb)->ack_seq)) { + 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; + 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 && + !after(ntohl(sp[0].end_seq), prior_snd_una) && + after(ntohl(sp[0].end_seq), tp->undo_marker)) + tp->undo_retrans--; + + /* Eliminate too old ACKs, but take into + * account more or less fresh ones, they can + * contain valid SACK info. + */ + if (before(TCP_SKB_CB(ack_skb)->ack_seq, prior_snd_una - tp->max_window)) + return 0; + /* SACK fastpath: * if the only SACK change is the increase of the end_seq of * the first block then only apply that SACK block * and use retrans queue hinting otherwise slowpath */ flag = 1; - for (i = 0; i< num_sacks; i++) { - __u32 start_seq = ntohl(sp[i].start_seq); - __u32 end_seq = ntohl(sp[i].end_seq); + for (i = 0; i < num_sacks; i++) { + __be32 start_seq = sp[i].start_seq; + __be32 end_seq = sp[i].end_seq; - if (i == 0){ + if (i == 0) { if (tp->recv_sack_cache[i].start_seq != start_seq) flag = 0; } else { @@ -970,37 +997,6 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ } tp->recv_sack_cache[i].start_seq = start_seq; tp->recv_sack_cache[i].end_seq = end_seq; - - /* Check for D-SACK. */ - if (i == 0) { - u32 ack = TCP_SKB_CB(ack_skb)->ack_seq; - - if (before(start_seq, ack)) { - dup_sack = 1; - tp->rx_opt.sack_ok |= 4; - NET_INC_STATS_BH(LINUX_MIB_TCPDSACKRECV); - } else if (num_sacks > 1 && - !after(end_seq, ntohl(sp[1].end_seq)) && - !before(start_seq, ntohl(sp[1].start_seq))) { - 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 && - !after(end_seq, prior_snd_una) && - after(end_seq, tp->undo_marker)) - tp->undo_retrans--; - - /* Eliminate too old ACKs, but take into - * account more or less fresh ones, they can - * contain valid SACK info. - */ - if (before(ack, prior_snd_una - tp->max_window)) - return 0; - } } first_sack_index = 0; |