Commit 253541a3 authored by Jason Xing's avatar Jason Xing Committed by David S. Miller
Browse files

tcp: use drop reasons in cookie check for ipv6 



Like what I did to ipv4 mode, refine this part: adding more drop
reasons for better tracing.

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 ed43e76c

net/ipv6/syncookies.c

+12 −4
Original line number Diff line number Diff line
@@ -190,16 +190,20 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) 
		if (IS_ERR(req))

			goto out;

	}

	if (!req)

	if (!req) {

		SKB_DR_SET(reason, NO_SOCKET);

		goto out_drop;

	}



	ireq = inet_rsk(req);



	ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;

	ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;



	if (security_inet_conn_request(sk, skb, req))

	if (security_inet_conn_request(sk, skb, req)) {

		SKB_DR_SET(reason, SECURITY_HOOK);

		goto out_free;

	}



	if (ipv6_opt_accepted(sk, skb, &TCP_SKB_CB(skb)->header.h6) ||

	    np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
@@ -236,9 +240,11 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) 
		security_req_classify_flow(req, flowi6_to_flowi_common(&fl6));



		dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p);

		if (IS_ERR(dst))

		if (IS_ERR(dst)) {

			SKB_DR_SET(reason, IP_OUTNOROUTES);

			goto out_free;

		}

	}



	req->rsk_window_clamp = tp->window_clamp ? :dst_metric(dst, RTAX_WINDOW);

	/* limit the window selection if the user enforce a smaller rx buffer */
@@ -257,8 +263,10 @@ 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)

	if (!ret) {

		SKB_DR_SET(reason, NO_SOCKET);

		goto out_drop;

	}

out:

	return ret;

out_free: