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Commit af9b4738 authored by Florian Westphal's avatar Florian Westphal Committed by David S. Miller
Browse files

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: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2a1d4bd4

net/ipv4/syncookies.c

+1 −1
Original line number Diff line number Diff line
@@ -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) ||

net/ipv4/tcp_ipv4.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

net/ipv6/syncookies.c

+1 −1
Original line number Diff line number Diff line
@@ -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) ||

net/ipv6/tcp_ipv6.c

+1 −1
Original line number Diff line number Diff line
@@ -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;