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| author | Jakub Kicinski <kuba@kernel.org> | 2020-02-02 13:39:11 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-02-02 13:45:05 -0800 |
| commit | 83d0585f91da441a0b11bc5ff93f4cda56de6703 (patch) | |
| tree | 32f2b03562a1bc6e2e0f725d7ff6ce15048be19f /net | |
| parent | dff6bc1bfd462b76dc13ec19dedc2c134a62ac59 (diff) | |
| parent | af8c8a450bf4698a8a6a7c68956ea5ccafe4cc88 (diff) | |
| download | linux-83d0585f91da441a0b11bc5ff93f4cda56de6703.tar.bz2 | |
Merge branch 'Fix-reconnection-latency-caused-by-FIN-ACK-handling-race'
SeongJae Park says:
====================
Fix reconnection latency caused by FIN/ACK handling race
The first patch fixes the problem by adjusting the first resend delay of
the SYN in the case. The second one adds a user space test to reproduce
this problem.
From v2
(https://lore.kernel.org/linux-kselftest/20200201071859.4231-1-sj38.park@gmail.com/)
- Use TCP_TIMEOUT_MIN as reduced delay (Neal Cardwall)
- Add Reviewed-by and Signed-off-by from Eric Dumazet
From v1
(https://lore.kernel.org/linux-kselftest/20200131122421.23286-1-sjpark@amazon.com/)
- Drop the trivial comment fix patch (Eric Dumazet)
- Limit the delay adjustment to only the first SYN resend (Eric Dumazet)
- selftest: Avoid use of hard-coded port number (Eric Dumazet)
- Explain RST/ACK and FIN/ACK has no big difference (Neal Cardwell)
====================
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_input.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index e325b4506e25..316ebdf8151d 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5908,8 +5908,14 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, * the segment and return)" */ if (!after(TCP_SKB_CB(skb)->ack_seq, tp->snd_una) || - after(TCP_SKB_CB(skb)->ack_seq, tp->snd_nxt)) + after(TCP_SKB_CB(skb)->ack_seq, tp->snd_nxt)) { + /* Previous FIN/ACK or RST/ACK might be ignored. */ + if (icsk->icsk_retransmits == 0) + inet_csk_reset_xmit_timer(sk, + ICSK_TIME_RETRANS, + TCP_TIMEOUT_MIN, TCP_RTO_MAX); goto reset_and_undo; + } if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr && !between(tp->rx_opt.rcv_tsecr, tp->retrans_stamp, |