Wolfgang reported that IPv6 stack is ignoring oif in output route lookups:

    With ipv6, ip -6 route get always returns the specific route.

    $ ip -6 r
    2001:db8:e2::1 dev enp2s0  proto kernel  metric 256
    2001:db8:e2::/64 dev enp2s0  metric 1024
    2001:db8:e3::1 dev enp3s0  proto kernel  metric 256
    2001:db8:e3::/64 dev enp3s0  metric 1024
    fe80::/64 dev enp3s0  proto kernel  metric 256
    default via 2001:db8:e3::255 dev enp3s0  metric 1024

    $ ip -6 r get 2001:db8:e2::100
    2001:db8:e2::100 from :: dev enp2s0  src 2001:db8:e3::1  metric 0
        cache

    $ ip -6 r get 2001:db8:e2::100 oif enp3s0
    2001:db8:e2::100 from :: dev enp2s0  src 2001:db8:e3::1  metric 0
        cache

The stack does consider the oif but a mismatch in rt6_device_match is not
considered fatal because RT6_LOOKUP_F_IFACE is not set in the flags.

Cc: Wolfgang Nothdurft <net...@linux-dude.de>
Signed-off-by: David Ahern <d...@cumulusnetworks.com>
---
 net/ipv6/route.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index f204089e854c..cb32ce250db0 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1193,7 +1193,8 @@ struct dst_entry *ip6_route_output(struct net *net, const 
struct sock *sk,
 
        fl6->flowi6_iif = LOOPBACK_IFINDEX;
 
-       if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr))
+       if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
+           fl6->flowi6_oif)
                flags |= RT6_LOOKUP_F_IFACE;
 
        if (!ipv6_addr_any(&fl6->saddr))
-- 
2.3.8 (Apple Git-58)

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to