ipmr: vrf: Find VIFs using the actual device

The skb->dev that is passed into ip_mr_input is
the loX device for VRFs. When we lookup a vif
for this dev, none is found as we do not create
vifs for loopbacks. Instead lookup a vif for the
actual device that the packet was received on,
eg the vlan.

Signed-off-by: Thomas Winter <Thomas.Winter@alliedtelesis.co.nz>
cc: David Ahern <dsa@cumulusnetworks.com>
cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
cc: roopa <roopa@cumulusnetworks.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 2 deletions

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 3a02d52ed50e..551de4d023a8 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1980,6 +1980,20 @@ int ip_mr_input(struct sk_buff *skb)
         struct net *net = dev_net(skb->dev);
         int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
         struct mr_table *mrt;
+        struct net_device *dev;
+
+        /* skb->dev passed in is the loX master dev for vrfs.
+         * As there are no vifs associated with loopback devices,
+         * get the proper interface that does have a vif associated with it.
+         */
+        dev = skb->dev;
+        if (netif_is_l3_master(skb->dev)) {
+                dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
+                if (!dev) {
+                        kfree_skb(skb);
+                        return -ENODEV;
+                }
+        }
 
         /* Packet is looped back after forward, it should not be
          * forwarded second time, but still can be delivered locally.
@@ -2017,7 +2031,7 @@ int ip_mr_input(struct sk_buff *skb)
         /* already under rcu_read_lock() */
         cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
         if (!cache) {
-                int vif = ipmr_find_vif(mrt, skb->dev);
+                int vif = ipmr_find_vif(mrt, dev);
 
                 if (vif >= 0)
                         cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
@@ -2037,7 +2051,7 @@ int ip_mr_input(struct sk_buff *skb)
                 }
 
                 read_lock(&mrt_lock);
-                vif = ipmr_find_vif(mrt, skb->dev);
+                vif = ipmr_find_vif(mrt, dev);
                 if (vif >= 0) {
                         int err2 = ipmr_cache_unresolved(mrt, vif, skb);
                         read_unlock(&mrt_lock);