Commit ed43e76c authored by Jason Xing's avatar Jason Xing Committed by David S. Miller
Browse files

tcp: directly drop skb in cookie check for ipv6 



Like previous patch does, only moving skb drop logical code to
cookie_v6_check() for later refinement.

Signed-off-by: default avatarJason Xing <kernelxing@tencent.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a4a69a37

net/ipv6/syncookies.c

+4 −0
Original line number Diff line number Diff line
@@ -177,6 +177,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) 
	struct sock *ret = sk;

	__u8 rcv_wscale;

	int full_space;

	SKB_DR(reason);



	if (!READ_ONCE(net->ipv4.sysctl_tcp_syncookies) ||

	    !th->ack || th->rst)
@@ -256,10 +257,13 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) 
	ireq->ecn_ok &= cookie_ecn_ok(net, dst);



	ret = tcp_get_cookie_sock(sk, skb, req, dst);

	if (!ret)

		goto out_drop;

out:

	return ret;

out_free:

	reqsk_free(req);

out_drop:

	kfree_skb_reason(skb, reason);

	return NULL;

}

net/ipv6/tcp_ipv6.c

+1 −4
Original line number Diff line number Diff line
@@ -1653,11 +1653,8 @@ int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) 
	if (sk->sk_state == TCP_LISTEN) {

		struct sock *nsk = tcp_v6_cookie_check(sk, skb);



		if (!nsk)

			goto discard;



		if (nsk != sk) {

			if (tcp_child_process(sk, nsk, skb))

			if (nsk && tcp_child_process(sk, nsk, skb))

				goto reset;

			if (opt_skb)

				__kfree_skb(opt_skb);