syncookies: avoid unneeded tcp header flag double check
caller: if (!th->rst && !th->syn && th->ack)
callee: if (!th->ack)
make the caller only check for !syn (common for 3whs), and move
the !rst / ack test to the callee.
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index e487080..5887141 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1157,7 +1157,7 @@
}
#ifdef CONFIG_SYN_COOKIES
- if (!th->rst && !th->syn && th->ack)
+ if (!th->syn)
sk = cookie_v6_check(sk, skb);
#endif
return sk;
