From 741a11d9e4103a8e1c590ef1280143fe654e4e33 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Mon, 28 Sep 2015 10:12:13 -0700 Subject: [PATCH] net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set 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 Signed-off-by: David Ahern Signed-off-by: David S. Miller --- 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)) -- 2.20.1