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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>
This commit is contained in:
Florian Westphal 2010-06-03 00:43:44 +00:00 committed by David S. Miller
parent 2a1d4bd460
commit af9b473857
4 changed files with 4 additions and 4 deletions
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2
net/ipv4/syncookies.c
View File

@ -266,7 +266,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
struct rtable *rt;
__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) ||

2
net/ipv4/tcp_ipv4.c
View File

@ -1506,7 +1506,7 @@ static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
}
#ifdef CONFIG_SYN_COOKIES
if (!th->rst && !th->syn && th->ack)
if (!th->syn)
sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt));
#endif
return sk;

2
net/ipv6/syncookies.c
View File

@ -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) ||

2
net/ipv6/tcp_ipv6.c
View File

@ -1157,7 +1157,7 @@ static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
}
#ifdef CONFIG_SYN_COOKIES
if (!th->rst && !th->syn && th->ack)
if (!th->syn)
sk = cookie_v6_check(sk, skb);
#endif
return sk;