From: David Ahern <dsa@cumulusnetworks.com>
Date: Mon, 5 Oct 2015 17:49:04 +0000 (-0700)
Subject: net: Lookup actual route when oif is VRF device
X-Git-Tag: firefly_0821_release~176^2~818^2~196
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=deaa0a6a930;p=firefly-linux-kernel-4.4.55.git

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 54e6f456a760..bf1486bd7e81 100644
--- 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;