diff options
Diffstat (limited to 'net/ipv4/tcp_recovery.c')
| -rw-r--r-- | net/ipv4/tcp_recovery.c | 41 |
1 files changed, 23 insertions, 18 deletions
diff --git a/net/ipv4/tcp_recovery.c b/net/ipv4/tcp_recovery.c index 7ea0377229c0..557363cde58a 100644 --- a/net/ipv4/tcp_recovery.c +++ b/net/ipv4/tcp_recovery.c @@ -32,7 +32,7 @@ static void tcp_rack_mark_skb_lost(struct sock *sk, struct sk_buff *skb) * The current version is only used after recovery starts but can be * easily extended to detect the first loss. */ -static void tcp_rack_detect_loss(struct sock *sk) +static void tcp_rack_detect_loss(struct sock *sk, const struct skb_mstamp *now) { struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *skb; @@ -62,13 +62,14 @@ static void tcp_rack_detect_loss(struct sock *sk) continue; if (skb_mstamp_after(&tp->rack.mstamp, &skb->skb_mstamp)) { - - if (skb_mstamp_us_delta(&tp->rack.mstamp, - &skb->skb_mstamp) <= reo_wnd) - continue; - - /* skb is lost if packet sent later is sacked */ - tcp_rack_mark_skb_lost(sk, skb); + /* Step 3 in draft-cheng-tcpm-rack-00.txt: + * A packet is lost if its elapsed time is beyond + * the recent RTT plus the reordering window. + */ + if (skb_mstamp_us_delta(now, &skb->skb_mstamp) > + tp->rack.rtt_us + reo_wnd) { + tcp_rack_mark_skb_lost(sk, skb); + } } else if (!(scb->sacked & TCPCB_RETRANS)) { /* Original data are sent sequentially so stop early * b/c the rest are all sent after rack_sent @@ -78,7 +79,7 @@ static void tcp_rack_detect_loss(struct sock *sk) } } -void tcp_rack_mark_lost(struct sock *sk) +void tcp_rack_mark_lost(struct sock *sk, const struct skb_mstamp *now) { struct tcp_sock *tp = tcp_sk(sk); @@ -86,20 +87,25 @@ void tcp_rack_mark_lost(struct sock *sk) return; /* Reset the advanced flag to avoid unnecessary queue scanning */ tp->rack.advanced = 0; - tcp_rack_detect_loss(sk); + tcp_rack_detect_loss(sk, now); } -/* Record the most recently (re)sent time among the (s)acked packets */ -void tcp_rack_advance(struct tcp_sock *tp, - const struct skb_mstamp *xmit_time, u8 sacked) +/* Record the most recently (re)sent time among the (s)acked packets + * This is "Step 3: Advance RACK.xmit_time and update RACK.RTT" from + * draft-cheng-tcpm-rack-00.txt + */ +void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, + const struct skb_mstamp *xmit_time, + const struct skb_mstamp *ack_time) { + u32 rtt_us; + if (tp->rack.mstamp.v64 && !skb_mstamp_after(xmit_time, &tp->rack.mstamp)) return; + rtt_us = skb_mstamp_us_delta(ack_time, xmit_time); if (sacked & TCPCB_RETRANS) { - struct skb_mstamp now; - /* If the sacked packet was retransmitted, it's ambiguous * whether the retransmission or the original (or the prior * retransmission) was sacked. @@ -110,11 +116,10 @@ void tcp_rack_advance(struct tcp_sock *tp, * so it's at least one RTT (i.e., retransmission is at least * an RTT later). */ - skb_mstamp_get(&now); - if (skb_mstamp_us_delta(&now, xmit_time) < tcp_min_rtt(tp)) + if (rtt_us < tcp_min_rtt(tp)) return; } - + tp->rack.rtt_us = rtt_us; tp->rack.mstamp = *xmit_time; tp->rack.advanced = 1; } |