From 55d8694fa82c9b5858ae5a78a210353961f908f9 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 26 Sep 2014 22:37:32 +0200 Subject: net: tcp: assign tcp cong_ops when tcp sk is created Split assignment and initialization from one into two functions. This is required by followup patches that add Datacenter TCP (DCTCP) congestion control algorithm - we need to be able to determine if the connection is moderated by DCTCP before the 3WHS has finished. As we walk the available congestion control list during the assignment, we are always guaranteed to have Reno present as it's fixed compiled-in. Therefore, since we're doing the early assignment, we don't have a real use for the Reno alias tcp_init_congestion_ops anymore and can thus remove it. Actual usage of the congestion control operations are being made after the 3WHS has finished, in some cases however we can access get_info() via diag if implemented, therefore we need to zero out the private area for those modules. Joint work with Daniel Borkmann and Glenn Judd. Signed-off-by: Florian Westphal Signed-off-by: Daniel Borkmann Signed-off-by: Glenn Judd Acked-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/ipv4/tcp_minisocks.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'net/ipv4/tcp_minisocks.c') diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index a058f411d3a6..47b73506b77e 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -451,9 +451,8 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req, newtp->snd_cwnd = TCP_INIT_CWND; newtp->snd_cwnd_cnt = 0; - 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; + if (!try_module_get(newicsk->icsk_ca_ops->owner)) + tcp_assign_congestion_control(newsk); tcp_set_ca_state(newsk, TCP_CA_Open); tcp_init_xmit_timers(newsk); -- cgit v1.2.3