net: tcp: assign tcp cong_ops when tcp sk is created
authorFlorian Westphal <fw@strlen.de>
Fri, 26 Sep 2014 20:37:32 +0000 (22:37 +0200)
committerDavid S. Miller <davem@davemloft.net>
Mon, 29 Sep 2014 04:13:10 +0000 (00:13 -0400)
commit55d8694fa82c9b5858ae5a78a210353961f908f9
treebf74f0684a951ecef52bd00300ad1db5d47fb05f
parent53dfd501819a6e9c3a7d56cac1ddaf03fe90800d
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 <fw@strlen.de>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/net/tcp.h
net/ipv4/tcp.c
net/ipv4/tcp_cong.c
net/ipv4/tcp_minisocks.c