net: mpls: Delete route when all nexthops have been deleted

When all devices for all nexthops in a route have been deleted, the
route is effectively dead, so remove it.

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

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 3861f8dfa9c1f933febf5fa5943d4855baa25402..74755920c6893ae3a08f993cabacf4230d16eaff 100644 (file)
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -1299,7 +1299,7 @@ static void mpls_ifdown(struct net_device *dev, int event)
        struct mpls_route __rcu **platform_label;
        struct net *net = dev_net(dev);
        unsigned int nh_flags = RTNH_F_DEAD | RTNH_F_LINKDOWN;
-       unsigned int alive;
+       unsigned int alive, deleted;
        unsigned index;
 
        platform_label = rtnl_dereference(net->mpls.platform_label);
@@ -1310,6 +1310,7 @@ static void mpls_ifdown(struct net_device *dev, int event)
                        continue;
 
                alive = 0;
+               deleted = 0;
                change_nexthops(rt) {
                        if (rtnl_dereference(nh->nh_dev) != dev)
                                goto next;
@@ -1328,9 +1329,15 @@ static void mpls_ifdown(struct net_device *dev, int event)
 next:
                        if (!(nh->nh_flags & nh_flags))
                                alive++;
+                       if (!rtnl_dereference(nh->nh_dev))
+                               deleted++;
                } endfor_nexthops(rt);
 
                WRITE_ONCE(rt->rt_nhn_alive, alive);
+
+               /* if there are no more nexthops, delete the route */
+               if (event == NETDEV_UNREGISTER && deleted == rt->rt_nhn)
+                       mpls_route_update(net, index, NULL, NULL);
        }
 }