net: Add netif_is_l3_slave

IPv6 addrconf keys off of IFF_SLAVE so can not use it for L3 slave.
Add a new private flag and add netif_is_l3_slave function for checking
it.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/vrf.c

@@ -39,8 +39,6 @@
 #define DRV_NAME	"vrf"
 #define DRV_VERSION	"1.0"
 
-#define vrf_is_slave(dev)   ((dev)->flags & IFF_SLAVE)
-
 #define vrf_master_get_rcu(dev) \
 	((struct net_device *)rcu_dereference(dev->rx_handler_data))
 
@@ -433,7 +431,7 @@ static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
 	if (ret < 0)
 		goto out_unregister;
 
-	port_dev->flags |= IFF_SLAVE;
+	port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
 	__vrf_insert_slave(queue, slave);
 	cycle_netdev(port_dev);
 
@@ -448,7 +446,7 @@ static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
 
 static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
 {
-	if (netif_is_l3_master(port_dev) || vrf_is_slave(port_dev))
+	if (netif_is_l3_master(port_dev) || netif_is_l3_slave(port_dev))
 		return -EINVAL;
 
 	return do_vrf_add_slave(dev, port_dev);
@@ -462,7 +460,7 @@ static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
 	struct slave *slave;
 
 	netdev_upper_dev_unlink(port_dev, dev);
-	port_dev->flags &= ~IFF_SLAVE;
+	port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
 
 	netdev_rx_handler_unregister(port_dev);
 
@@ -672,7 +670,7 @@ static int vrf_device_event(struct notifier_block *unused,
 	if (event == NETDEV_UNREGISTER) {
 		struct net_device *vrf_dev;
 
-		if (!vrf_is_slave(dev) || netif_is_l3_master(dev))
+		if (!netif_is_l3_slave(dev))
 			goto out;
 
 		vrf_dev = netdev_master_upper_dev_get(dev);

include/linux/netdevice.h

@@ -1261,6 +1261,7 @@ struct net_device_ops {
  * @IFF_L3MDEV_MASTER: device is an L3 master device
  * @IFF_NO_QUEUE: device can run without qdisc attached
  * @IFF_OPENVSWITCH: device is a Open vSwitch master
+ * @IFF_L3MDEV_SLAVE: device is enslaved to an L3 master device
  */
 enum netdev_priv_flags {
 	IFF_802_1Q_VLAN			= 1<<0,
@@ -1286,6 +1287,7 @@ enum netdev_priv_flags {
 	IFF_L3MDEV_MASTER		= 1<<20,
 	IFF_NO_QUEUE			= 1<<21,
 	IFF_OPENVSWITCH			= 1<<22,
+	IFF_L3MDEV_SLAVE		= 1<<23,
 };
 
 #define IFF_802_1Q_VLAN			IFF_802_1Q_VLAN
@@ -3830,6 +3832,11 @@ static inline bool netif_is_l3_master(const struct net_device *dev)
 	return dev->priv_flags & IFF_L3MDEV_MASTER;
 }
 
+static inline bool netif_is_l3_slave(const struct net_device *dev)
+{
+	return dev->priv_flags & IFF_L3MDEV_SLAVE;
+}
+
 static inline bool netif_is_bridge_master(const struct net_device *dev)
 {
 	return dev->priv_flags & IFF_EBRIDGE;

net/l3mdev/l3mdev.c

@@ -26,11 +26,11 @@ int l3mdev_master_ifindex_rcu(struct net_device *dev)
 
 	if (netif_is_l3_master(dev)) {
 		ifindex = dev->ifindex;
-	} else if (dev->flags & IFF_SLAVE) {
+	} else if (netif_is_l3_slave(dev)) {
 		struct net_device *master;
 
 		master = netdev_master_upper_dev_get_rcu(dev);
-		if (master && netif_is_l3_master(master))
+		if (master)
 			ifindex = master->ifindex;
 	}
 
@@ -54,7 +54,7 @@ u32 l3mdev_fib_table_rcu(const struct net_device *dev)
 	if (netif_is_l3_master(dev)) {
 		if (dev->l3mdev_ops->l3mdev_fib_table)
 			tb_id = dev->l3mdev_ops->l3mdev_fib_table(dev);
-	} else if (dev->flags & IFF_SLAVE) {
+	} else if (netif_is_l3_slave(dev)) {
 		/* Users of netdev_master_upper_dev_get_rcu need non-const,
 		 * but current inet_*type functions take a const
 		 */
@@ -62,7 +62,7 @@ u32 l3mdev_fib_table_rcu(const struct net_device *dev)
 		const struct net_device *master;
 
 		master = netdev_master_upper_dev_get_rcu(_dev);
-		if (master && netif_is_l3_master(master) &&
+		if (master &&
 		    master->l3mdev_ops->l3mdev_fib_table)
 			tb_id = master->l3mdev_ops->l3mdev_fib_table(master);
 	}