veth: set iflink to the peer veth

Now that the peer netns is advertised in rtnl messages, we can set this property
so that IFLA_LINK will advertise the peer ifindex. It allows the userland to get
the full veth configuration.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 4cca36ebc4fb..c8186ffda1a3 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -263,6 +263,20 @@ static void veth_poll_controller(struct net_device *dev)
 }
 #endif  /* CONFIG_NET_POLL_CONTROLLER */
 
+static int veth_get_iflink(const struct net_device *dev)
+{
+        struct veth_priv *priv = netdev_priv(dev);
+        struct net_device *peer;
+        int iflink;
+
+        rcu_read_lock();
+        peer = rcu_dereference(priv->peer);
+        iflink = peer ? peer->ifindex : 0;
+        rcu_read_unlock();
+
+        return iflink;
+}
+
 static const struct net_device_ops veth_netdev_ops = {
         .ndo_init            = veth_dev_init,
         .ndo_open            = veth_open,
@@ -275,6 +289,7 @@ static const struct net_device_ops veth_netdev_ops = {
 #ifdef CONFIG_NET_POLL_CONTROLLER
         .ndo_poll_controller    = veth_poll_controller,
 #endif
+        .ndo_get_iflink         = veth_get_iflink,
 };
 
 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_ALL_TSO |    \