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| author | Eric Dumazet <edumazet@google.com> | 2019-09-30 15:44:44 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-07 18:58:24 +0200 |
| commit | da0f508134bb76e6b535faa0c303f9785188fea6 (patch) | |
| tree | a7fbd2fb2cb5cb846ff4681eea646b588c8f956a /net | |
| parent | c5994847e736d46a282ae16ae622378ab1097dc4 (diff) | |
| download | linux-stable-da0f508134bb76e6b535faa0c303f9785188fea6.tar.gz linux-stable-da0f508134bb76e6b535faa0c303f9785188fea6.tar.bz2 linux-stable-da0f508134bb76e6b535faa0c303f9785188fea6.zip | |
tcp: adjust rto_base in retransmits_timed_out()
[ Upstream commit 3256a2d6ab1f71f9a1bd2d7f6f18eb8108c48d17 ]
The cited commit exposed an old retransmits_timed_out() bug
which assumed it could call tcp_model_timeout() with
TCP_RTO_MIN as rto_base for all states.
But flows in SYN_SENT or SYN_RECV state uses a different
RTO base (1 sec instead of 200 ms, unless BPF choses
another value)
This caused a reduction of SYN retransmits from 6 to 4 with
the default /proc/sys/net/ipv4/tcp_syn_retries value.
Fixes: a41e8a88b06e ("tcp: better handle TCP_USER_TIMEOUT in SYN_SENT state")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Marek Majkowski <marek@cloudflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_timer.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 3e8b38c73d8c..483323332d74 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -198,8 +198,13 @@ static bool retransmits_timed_out(struct sock *sk, return false; start_ts = tcp_sk(sk)->retrans_stamp; - if (likely(timeout == 0)) - timeout = tcp_model_timeout(sk, boundary, TCP_RTO_MIN); + if (likely(timeout == 0)) { + unsigned int rto_base = TCP_RTO_MIN; + + if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) + rto_base = tcp_timeout_init(sk); + timeout = tcp_model_timeout(sk, boundary, rto_base); + } return (s32)(tcp_time_stamp(tcp_sk(sk)) - start_ts - timeout) >= 0; } |