net: Lookup actual route when oif is VRF device

If the user specifies a VRF device in a get route query the custom route
pointing to the VRF device is returned:

    $ ip route ls table vrf-red
    unreachable default
    broadcast 10.2.1.0 dev eth1  proto kernel  scope link  src 10.2.1.2
    10.2.1.0/24 dev eth1  proto kernel  scope link  src 10.2.1.2
    local 10.2.1.2 dev eth1  proto kernel  scope host  src 10.2.1.2
    broadcast 10.2.1.255 dev eth1  proto kernel  scope link  src 10.2.1.2

    $ ip route get oif vrf-red 10.2.1.40
    10.2.1.40 dev vrf-red
        cache

Add the flags to skip the custom route and go directly to the FIB. With
this patch the actual route is returned:

    $ ip route get oif vrf-red 10.2.1.40
    10.2.1.40 dev eth1  src 10.2.1.2
        cache

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 54e6f45..bf1486b 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2507,6 +2507,9 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh)
        fl4.flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0;
        fl4.flowi4_mark = mark;
 
+       if (netif_index_is_l3_master(net, fl4.flowi4_oif))
+               fl4.flowi4_flags = FLOWI_FLAG_L3MDEV_SRC | FLOWI_FLAG_SKIP_NH_OIF;
+
        if (iif) {
                struct net_device *dev;