summaryrefslogtreecommitdiff
path: root/net/ipv4/tcp_input.c
diff options
context:
space:
mode:
authorDavid S. Miller <davem@davemloft.net>2017-04-15 21:16:30 -0400
committerDavid S. Miller <davem@davemloft.net>2017-04-15 21:16:30 -0400
commit6b6cbc1471676402565e958674523d06213b82d7 (patch)
treea66d41d276e5eb400e27641f24f34032fe1b9275 /net/ipv4/tcp_input.c
parentce07183282975026716107d36fd3f5f93de76668 (diff)
parent1bf4b1268e66d9364fc6fd41f906bc01458530ac (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts were simply overlapping changes. In the net/ipv4/route.c case the code had simply moved around a little bit and the same fix was made in both 'net' and 'net-next'. In the net/sched/sch_generic.c case a fix in 'net' happened at the same time that a new argument was added to qdisc_hash_add(). Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c20
1 files changed, 12 insertions, 8 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 31f2765ef851..a5838858c362 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1935,6 +1935,7 @@ void tcp_enter_loss(struct sock *sk)
struct tcp_sock *tp = tcp_sk(sk);
struct net *net = sock_net(sk);
struct sk_buff *skb;
+ bool new_recovery = icsk->icsk_ca_state < TCP_CA_Recovery;
bool is_reneg; /* is receiver reneging on SACKs? */
bool mark_lost;
@@ -1994,15 +1995,18 @@ void tcp_enter_loss(struct sock *sk)
tp->high_seq = tp->snd_nxt;
tcp_ecn_queue_cwr(tp);
- /* F-RTO RFC5682 sec 3.1 step 1 mandates to disable F-RTO
- * if a previous recovery is underway, otherwise it may incorrectly
- * call a timeout spurious if some previously retransmitted packets
- * are s/acked (sec 3.2). We do not apply that retriction since
- * retransmitted skbs are permanently tagged with TCPCB_EVER_RETRANS
- * so FLAG_ORIG_SACK_ACKED is always correct. But we do disable F-RTO
- * on PTMU discovery to avoid sending new data.
+ /* F-RTO RFC5682 sec 3.1 step 1: retransmit SND.UNA if no previous
+ * loss recovery is underway except recurring timeout(s) on
+ * the same SND.UNA (sec 3.2). Disable F-RTO on path MTU probing
+ *
+ * In theory F-RTO can be used repeatedly during loss recovery.
+ * In practice this interacts badly with broken middle-boxes that
+ * falsely raise the receive window, which results in repeated
+ * timeouts and stop-and-go behavior.
*/
- tp->frto = sysctl_tcp_frto && !inet_csk(sk)->icsk_mtup.probe_size;
+ tp->frto = sysctl_tcp_frto &&
+ (new_recovery || icsk->icsk_retransmits) &&
+ !inet_csk(sk)->icsk_mtup.probe_size;
}
/* If ACK arrived pointing to a remembered SACK, it means that our