ipv6: do not use RT_TOS for IPv6 flowlabel

commit ab7e2e0dfa5d37540ab1dc5376e9a2cb9188925d upstream.

According to Guillaume Nault RT_TOS should never be used for IPv6.

Quote:
RT_TOS() is an old macro used to interprete IPv4 TOS as described in
the obsolete RFC 1349. It's conceptually wrong to use it even in IPv4
code, although, given the current state of the code, most of the
existing calls have no consequence.

But using RT_TOS() in IPv6 code is always a bug: IPv6 never had a "TOS"
field to be interpreted the RFC 1349 way. There's no historical
compatibility to worry about.

Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Matthias May <matthias.may@westermo.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 05e19e5d65140276f2060cf1851845b19fb4d6f3..fadad8e83521d550ff7b72ae3ff60c43ef151e84 100644 (file)
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1313,8 +1313,7 @@ struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb,
        fl6.daddr = info->key.u.ipv6.dst;
        fl6.saddr = info->key.u.ipv6.src;
        prio = info->key.tos;
-       fl6.flowlabel = ip6_make_flowinfo(RT_TOS(prio),
-                                         info->key.label);
+       fl6.flowlabel = ip6_make_flowinfo(prio, info->key.label);
 
        dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6,
                                              NULL);