Commit e92dd77e authored by Wei Wang's avatar Wei Wang Committed by David S. Miller
Browse files

ipv6: add tos reflection in TCP reset and ack 



Currently, ipv6 stack does not do any TOS reflection. To make the
behavior consistent with v4 stack, this commit adds TOS reflection in
tcp_v6_reqsk_send_ack() and tcp_v6_send_reset(). We clear the lower
2-bit ECN value of the received TOS in compliance with RFC 3168 6.1.5
robustness principles.

Signed-off-by: default avatarWei Wang <weiwan@google.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 56bbc22d

net/ipv6/tcp_ipv6.c

+5 −5
Original line number Diff line number Diff line
@@ -959,8 +959,8 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 
	dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL);

	if (!IS_ERR(dst)) {

		skb_dst_set(buff, dst);

		ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, tclass,

			 priority);

		ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL,

			 tclass & ~INET_ECN_MASK, priority);

		TCP_INC_STATS(net, TCP_MIB_OUTSEGS);

		if (rst)

			TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
@@ -1068,8 +1068,8 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) 
			label = ip6_flowlabel(ipv6h);

	}



	tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0,

			     label, priority);

	tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1,

			     ipv6_get_dsfield(ipv6h), label, priority);



#ifdef CONFIG_TCP_MD5SIG

out:
@@ -1122,7 +1122,7 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, 
			tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,

			req->ts_recent, sk->sk_bound_dev_if,

			tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index),

			0, 0, sk->sk_priority);

			ipv6_get_dsfield(ipv6_hdr(skb)), 0, sk->sk_priority);

}