tcp: inherit listener congestion control for passive cnx
Rick Jones reported that TCP_CONGESTION sockopt performed on a listener
was ignored for its children sockets : right after accept() the
congestion control for new socket is the system default one.
This seems an oversight of the initial design (quoted from Stephen)
Based on prior investigation and patch from Rick.
Reported-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Yuchung Cheng <ycheng@google.com>
Tested-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index a9db4b1..c4b8b09 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1511,6 +1511,7 @@
return NULL;
put_and_exit:
tcp_clear_xmit_timers(newsk);
+ tcp_cleanup_congestion_control(newsk);
bh_unlock_sock(newsk);
sock_put(newsk);
goto exit;
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 945efff..9dc146e 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -495,7 +495,9 @@
newtp->frto_counter = 0;
newtp->frto_highmark = 0;
- newicsk->icsk_ca_ops = &tcp_init_congestion_ops;
+ if (newicsk->icsk_ca_ops != &tcp_init_congestion_ops &&
+ !try_module_get(newicsk->icsk_ca_ops->owner))
+ newicsk->icsk_ca_ops = &tcp_init_congestion_ops;
tcp_set_ca_state(newsk, TCP_CA_Open);
tcp_init_xmit_timers(newsk);