From db8da6bb574e1692cb86624317c572b0b9306560 Mon Sep 17 00:00:00 2001 From: Yuchung Cheng Date: Thu, 12 Jan 2017 22:11:30 -0800 Subject: [PATCH] tcp: new helper function for RACK loss detection Create a new helper tcp_rack_mark_skb_lost to prepare the upcoming RACK reordering timer support. Signed-off-by: Yuchung Cheng Signed-off-by: Neal Cardwell Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_recovery.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/net/ipv4/tcp_recovery.c b/net/ipv4/tcp_recovery.c index e36df4fcfeba..f38dba5aed7a 100644 --- a/net/ipv4/tcp_recovery.c +++ b/net/ipv4/tcp_recovery.c @@ -3,6 +3,19 @@ int sysctl_tcp_recovery __read_mostly = TCP_RACK_LOST_RETRANS; +static void tcp_rack_mark_skb_lost(struct sock *sk, struct sk_buff *skb) +{ + struct tcp_sock *tp = tcp_sk(sk); + + tcp_skb_mark_lost_uncond_verify(tp, skb); + if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) { + /* Account for retransmits that are lost again */ + TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS; + tp->retrans_out -= tcp_skb_pcount(skb); + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPLOSTRETRANSMIT); + } +} + /* Marks a packet lost, if some packet sent later has been (s)acked. * The underlying idea is similar to the traditional dupthresh and FACK * but they look at different metrics: @@ -61,13 +74,7 @@ int tcp_rack_mark_lost(struct sock *sk) continue; /* skb is lost if packet sent later is sacked */ - tcp_skb_mark_lost_uncond_verify(tp, skb); - if (scb->sacked & TCPCB_SACKED_RETRANS) { - scb->sacked &= ~TCPCB_SACKED_RETRANS; - tp->retrans_out -= tcp_skb_pcount(skb); - NET_INC_STATS(sock_net(sk), - LINUX_MIB_TCPLOSTRETRANSMIT); - } + 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 -- 2.20.1