[PATCH 5.19 121/365] vxlan: do not use RT_TOS for IPv6 flowlabel

From: Greg Kroah-Hartman
Date: Tue Aug 23 2022 - 04:32:58 EST


From: Matthias May <matthias.may@xxxxxxxxxxxx>

commit e488d4f5d6e4cd1e728ba4ddbdcd7ef5f4d13a21 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: 1400615d64cf ("vxlan: allow setting ipv6 traffic class")
Acked-by: Guillaume Nault <gnault@xxxxxxxxxx>
Signed-off-by: Matthias May <matthias.may@xxxxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/vxlan/vxlan_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -2321,7 +2321,7 @@ static struct dst_entry *vxlan6_get_rout
fl6.flowi6_oif = oif;
fl6.daddr = *daddr;
fl6.saddr = *saddr;
- fl6.flowlabel = ip6_make_flowinfo(RT_TOS(tos), label);
+ fl6.flowlabel = ip6_make_flowinfo(tos, label);
fl6.flowi6_mark = skb->mark;
fl6.flowi6_proto = IPPROTO_UDP;
fl6.fl6_dport = dport;