[NETNS]: Tcp-v4 sockets per-net lookup.

Add a net argument to inet_lookup and propagate it further
into lookup calls. Plus tune the __inet_check_established.

The dccp and inet_diag, which use that lookup functions
pass the init_net into them.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 4cfb15c..95c9f14 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -268,7 +268,7 @@
 	err = -EINVAL;
 
 	if (req->idiag_family == AF_INET) {
-		sk = inet_lookup(hashinfo, req->id.idiag_dst[0],
+		sk = inet_lookup(&init_net, hashinfo, req->id.idiag_dst[0],
 				 req->id.idiag_dport, req->id.idiag_src[0],
 				 req->id.idiag_sport, req->id.idiag_if);
 	}