tcp: move around a few calls in tcp_v6_conn_request

Make the tcp_v6_conn_request calls flow similar with that of
tcp_v4_conn_request.

Note that want_cookie can be true only if isn is zero and that is why
we can move the if (want_cookie) block out of the if (!isn) block.

Moving security_inet_conn_request() has a couple of side effects:
missing inet_rsk(req)->ecn_ok update and the req->cookie_ts
update. However, neither SELinux nor Smack security hooks seems to
check them. This change should also avoid future different behaviour
for IPv4 and IPv6 in the security hooks.

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 11 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index d780d8808566..91b8a2e699f3 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1070,16 +1070,16 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
         ireq = inet_rsk(req);
         af_ops->init_req(req, sk, skb);
 
+        if (security_inet_conn_request(sk, skb, req))
+                goto drop_and_release;
+
         if (!want_cookie || tmp_opt.tstamp_ok)
                 TCP_ECN_create_request(req, skb, sock_net(sk));
 
-        if (!isn) {
-                if (want_cookie) {
-                        isn = cookie_init_sequence(af_ops, sk, skb, &req->mss);
-                        req->cookie_ts = tmp_opt.tstamp_ok;
-                        goto have_isn;
-                }
-
+        if (want_cookie) {
+                isn = cookie_init_sequence(af_ops, sk, skb, &req->mss);
+                req->cookie_ts = tmp_opt.tstamp_ok;
+        } else if (!isn) {
                 /* VJ's idea. We save last timestamp seen
                  * from the destination in peer table, when entering
                  * state TIME-WAIT, and check against it before
@@ -1116,10 +1116,6 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 
                 isn = tcp_v6_init_sequence(skb);
         }
-have_isn:
-
-        if (security_inet_conn_request(sk, skb, req))
-                goto drop_and_release;
 
         if (!dst) {
                 dst = af_ops->route_req(sk, (struct flowi *)&fl6, req, NULL);