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authorEric Dumazet <eric.dumazet@gmail.com>2011-11-30 01:02:41 +0000
committerDavid S. Miller <davem@davemloft.net>2011-11-30 16:55:26 -0500
commitd8a6e65f8b6b6b0142ebab578472906d89d63657 (patch)
treea0231b1aa1c44252c79c9cb769bd0695e021f1b6
parentde565664041d954b60f87e3d576a784cf25672d0 (diff)
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>
-rw-r--r--Documentation/networking/ip-sysctl.txt3
-rw-r--r--net/ipv4/tcp_ipv4.c1
-rw-r--r--net/ipv4/tcp_minisocks.c4
3 files changed, 7 insertions, 1 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index b8867061fce..cb2b1c6a2ce 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -175,6 +175,9 @@ tcp_congestion_control - STRING
connections. The algorithm "reno" is always available, but
additional choices may be available based on kernel configuration.
Default is set as part of kernel configuration.
+ For passive connections, the listener congestion control choice
+ is inherited.
+ [see setsockopt(listenfd, SOL_TCP, TCP_CONGESTION, "name" ...) ]
tcp_cookie_size - INTEGER
Default size of TCP Cookie Transactions (TCPCT) option, that may be
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index a9db4b1a221..c4b8b09db9f 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1511,6 +1511,7 @@ exit:
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 945efffdd92..9dc146e5ed6 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -495,7 +495,9 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req,
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);