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 <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_recovery.c b/net/ipv4/tcp_recovery.c
index e36df4f..f38dba5 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 @@
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