From: Wei Wang Date: Tue, 8 Sep 2020 21:29:02 +0000 (-0700) Subject: ipv6: add tos reflection in TCP reset and ack X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=e92dd77e6fe0a33d356cab4f362dbfbb3b873c96;p=linux.git 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: Wei Wang Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 87a633e1fbefd..04efa3ee80ef4 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -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); }