SELinux: Return correct context for SO_PEERSEC

Fix SO_PEERSEC for tcp sockets to return the security context of
the peer (as represented by the SA from the peer) as opposed to the
SA used by the local/source socket.

Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index cf06acc..4a8c96c 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4230,6 +4230,8 @@
 		mb();
 		tcp_set_state(sk, TCP_ESTABLISHED);
 
+		security_inet_conn_established(sk, skb);
+
 		/* Make sure socket is routed, for correct metrics.  */
 		icsk->icsk_af_ops->rebuild_header(sk);