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 <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 12383705dbad..9fcb3ec7c838 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -174,7 +174,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
         struct dst_entry *dst;
         __u8 rcv_wscale;
 
-        if (!sysctl_tcp_syncookies || !th->ack)
+        if (!sysctl_tcp_syncookies || !th->ack || th->rst)
                 goto out;
 
         if (tcp_synq_no_recent_overflow(sk) ||