From 9f7b3a69c88daabaacc6596c6409ff52e57d3067 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Maciej=20=C5=BBenczykowski?= Date: Tue, 23 Nov 2021 14:31:54 -0800 Subject: [PATCH] net-ipv6: do not allow IPV6_TCLASS to muck with tcp's ECN MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This is to match ipv4 behaviour, see __ip_sock_set_tos() implementation at ipv4/ip_sockglue.c:579 void __ip_sock_set_tos(struct sock *sk, int val) { if (sk->sk_type == SOCK_STREAM) { val &= ~INET_ECN_MASK; val |= inet_sk(sk)->tos & INET_ECN_MASK; } if (inet_sk(sk)->tos != val) { inet_sk(sk)->tos = val; sk->sk_priority = rt_tos2priority(val); sk_dst_reset(sk); } } Cc: Neal Cardwell Signed-off-by: Maciej Żenczykowski Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20211123223154.1117794-1-zenczykowski@gmail.com Signed-off-by: Jakub Kicinski --- net/ipv6/ipv6_sockglue.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index 04683ad6d3df..8970b1a45257 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -599,6 +599,10 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname, /* RFC 3542, 6.5: default traffic class of 0x0 */ if (val == -1) val = 0; + if (sk->sk_type == SOCK_STREAM) { + val &= ~INET_ECN_MASK; + val |= np->tclass & INET_ECN_MASK; + } np->tclass = val; retv = 0; break;