diff options
| -rw-r--r-- | net/ipv4/tcp_input.c | 192 |
1 files changed, 96 insertions, 96 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 5e01ac2c003..a62e0f90f56 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1240,6 +1240,99 @@ static int tcp_match_skb_to_sack(struct sock *sk, struct sk_buff *skb, return in_sack; } +static int tcp_sacktag_one(struct sk_buff *skb, struct tcp_sock *tp, + int *reord, int dup_sack, int fack_count) +{ + u8 sacked = TCP_SKB_CB(skb)->sacked; + int flag = 0; + + /* Account D-SACK for retransmitted packet. */ + if (dup_sack && (sacked & TCPCB_RETRANS)) { + if (after(TCP_SKB_CB(skb)->end_seq, tp->undo_marker)) + tp->undo_retrans--; + if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una) && + (sacked & TCPCB_SACKED_ACKED)) + *reord = min(fack_count, *reord); + } + + /* Nothing to do; acked frame is about to be dropped (was ACKed). */ + if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una)) + return flag; + + if (!(sacked & TCPCB_SACKED_ACKED)) { + if (sacked & TCPCB_SACKED_RETRANS) { + /* If the segment is not tagged as lost, + * we do not clear RETRANS, believing + * that retransmission is still in flight. + */ + if (sacked & TCPCB_LOST) { + TCP_SKB_CB(skb)->sacked &= + ~(TCPCB_LOST|TCPCB_SACKED_RETRANS); + tp->lost_out -= tcp_skb_pcount(skb); + tp->retrans_out -= tcp_skb_pcount(skb); + + /* clear lost hint */ + tp->retransmit_skb_hint = NULL; + } + } else { + if (!(sacked & TCPCB_RETRANS)) { + /* New sack for not retransmitted frame, + * which was in hole. It is reordering. + */ + if (before(TCP_SKB_CB(skb)->seq, + tcp_highest_sack_seq(tp))) + *reord = min(fack_count, *reord); + + /* SACK enhanced F-RTO (RFC4138; Appendix B) */ + if (!after(TCP_SKB_CB(skb)->end_seq, tp->frto_highmark)) + flag |= FLAG_ONLY_ORIG_SACKED; + } + + if (sacked & TCPCB_LOST) { + TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST; + tp->lost_out -= tcp_skb_pcount(skb); + + /* clear lost hint */ + tp->retransmit_skb_hint = NULL; + } + } + + TCP_SKB_CB(skb)->sacked |= TCPCB_SACKED_ACKED; + flag |= FLAG_DATA_SACKED; + tp->sacked_out += tcp_skb_pcount(skb); + + fack_count += tcp_skb_pcount(skb); + + /* Lost marker hint past SACKed? Tweak RFC3517 cnt */ + if (!tcp_is_fack(tp) && (tp->lost_skb_hint != NULL) && + before(TCP_SKB_CB(skb)->seq, + TCP_SKB_CB(tp->lost_skb_hint)->seq)) + tp->lost_cnt_hint += tcp_skb_pcount(skb); + + if (fack_count > tp->fackets_out) + tp->fackets_out = fack_count; + + if (after(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp))) + tp->highest_sack = skb; + + } else { + if (dup_sack && (sacked & TCPCB_RETRANS)) + *reord = min(fack_count, *reord); + } + + /* D-SACK. We can detect redundant retransmission in S|R and plain R + * frames and clear it. undo_retrans is decreased above, L|R frames + * are accounted above as well. + */ + if (dup_sack && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)) { + TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS; + tp->retrans_out -= tcp_skb_pcount(skb); + tp->retransmit_skb_hint = NULL; + } + + return flag; +} + static int tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_una) { @@ -1375,7 +1468,6 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ tcp_for_write_queue_from(skb, sk) { int in_sack = 0; - u8 sacked; if (skb == tcp_send_head(sk)) break; @@ -1413,102 +1505,10 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ if (unlikely(in_sack < 0)) break; - if (!in_sack) { - fack_count += tcp_skb_pcount(skb); - continue; - } - - sacked = TCP_SKB_CB(skb)->sacked; - - /* Account D-SACK for retransmitted packet. */ - if (dup_sack && (sacked & TCPCB_RETRANS)) { - if (after(TCP_SKB_CB(skb)->end_seq, tp->undo_marker)) - tp->undo_retrans--; - if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una) && - (sacked & TCPCB_SACKED_ACKED)) - reord = min(fack_count, reord); - } - - - /* Nothing to do; acked frame is about to be dropped (was ACKed). */ - if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una)) { - fack_count += tcp_skb_pcount(skb); - continue; - } - - if (!(sacked&TCPCB_SACKED_ACKED)) { - if (sacked & TCPCB_SACKED_RETRANS) { - /* If the segment is not tagged as lost, - * we do not clear RETRANS, believing - * that retransmission is still in flight. - */ - if (sacked & TCPCB_LOST) { - TCP_SKB_CB(skb)->sacked &= ~(TCPCB_LOST|TCPCB_SACKED_RETRANS); - tp->lost_out -= tcp_skb_pcount(skb); - tp->retrans_out -= tcp_skb_pcount(skb); - - /* clear lost hint */ - tp->retransmit_skb_hint = NULL; - } - } else { - if (!(sacked & TCPCB_RETRANS)) { - /* New sack for not retransmitted frame, - * which was in hole. It is reordering. - */ - if (before(TCP_SKB_CB(skb)->seq, - tcp_highest_sack_seq(tp))) - reord = min(fack_count, reord); - - /* SACK enhanced F-RTO (RFC4138; Appendix B) */ - if (!after(TCP_SKB_CB(skb)->end_seq, tp->frto_highmark)) - flag |= FLAG_ONLY_ORIG_SACKED; - } - - if (sacked & TCPCB_LOST) { - TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST; - tp->lost_out -= tcp_skb_pcount(skb); - - /* clear lost hint */ - tp->retransmit_skb_hint = NULL; - } - } - - TCP_SKB_CB(skb)->sacked |= TCPCB_SACKED_ACKED; - flag |= FLAG_DATA_SACKED; - tp->sacked_out += tcp_skb_pcount(skb); - - fack_count += tcp_skb_pcount(skb); - - /* Lost marker hint past SACKed? Tweak RFC3517 cnt */ - if (!tcp_is_fack(tp) && (tp->lost_skb_hint != NULL) && - before(TCP_SKB_CB(skb)->seq, - TCP_SKB_CB(tp->lost_skb_hint)->seq)) - tp->lost_cnt_hint += tcp_skb_pcount(skb); - - if (fack_count > tp->fackets_out) - tp->fackets_out = fack_count; + if (in_sack) + flag |= tcp_sacktag_one(skb, tp, &reord, dup_sack, fack_count); - if (after(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp))) - tp->highest_sack = skb; - - } else { - if (dup_sack && (sacked&TCPCB_RETRANS)) - reord = min(fack_count, reord); - - fack_count += tcp_skb_pcount(skb); - } - - /* D-SACK. We can detect redundant retransmission - * in S|R and plain R frames and clear it. - * undo_retrans is decreased above, L|R frames - * are accounted above as well. - */ - if (dup_sack && - (TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_RETRANS)) { - TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS; - tp->retrans_out -= tcp_skb_pcount(skb); - tp->retransmit_skb_hint = NULL; - } + fack_count += tcp_skb_pcount(skb); } /* SACK enhanced FRTO (RFC4138, Appendix B): Clearing correct |