netdev - [PATCH net-next] ipv6: add tos reflection in TCP reset and ack

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200908212902.3525935-1-weiwan@google.com>
Date:   Tue,  8 Sep 2020 14:29:02 -0700
From:   Wei Wang <weiwan@...gle.com>
To:     "David S . Miller" <davem@...emloft.net>, netdev@...r.kernel.org
Cc:     Wei Wang <weiwan@...gle.com>, Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH net-next] 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 <weiwan@...gle.com>
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
 net/ipv6/tcp_ipv6.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 87a633e1fbef..04efa3ee80ef 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);
 }
 
 
-- 
2.28.0.526.ge36021eeef-goog