net: add netnotifier event for upper device change

Now when upper device is changed, event is not propagated via RT Netlink
to userspace. Userspace might never now about the change. Fix this by
adding upper-device-change notifier event.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 3 insertions, 1 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 0ebd63ae2cc8..ea7b6bce9ea0 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1593,6 +1593,7 @@ struct packet_offload {
 #define NETDEV_RELEASE          0x0012
 #define NETDEV_NOTIFY_PEERS     0x0013
 #define NETDEV_JOIN             0x0014
+#define NETDEV_CHANGEUPPER      0x0015
 
 extern int register_netdevice_notifier(struct notifier_block *nb);
 extern int unregister_netdevice_notifier(struct notifier_block *nb);
diff --git a/net/core/dev.c b/net/core/dev.c
index 7229bc30e509..50c02ded1d69 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4411,7 +4411,7 @@ static int __netdev_upper_dev_link(struct net_device *dev,
         else
                 list_add_tail_rcu(&upper->list, &dev->upper_dev_list);
         dev_hold(upper_dev);
-
+        call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
         return 0;
 }
 
@@ -4471,6 +4471,7 @@ void netdev_upper_dev_unlink(struct net_device *dev,
         list_del_rcu(&upper->list);
         dev_put(upper_dev);
         kfree_rcu(upper, rcu);
+        call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
 }
 EXPORT_SYMBOL(netdev_upper_dev_unlink);