bridge: Allow querying bridge port flags

Allow querying bridge port flags so that drivers capable of performing
VxLAN learning will update the bridge driver only if learning is enabled
on its bridge port corresponding to the VxLAN device.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/if_bridge.h

@@ -119,6 +119,7 @@ static inline int br_vlan_get_info(const struct net_device *dev, u16 vid,
 struct net_device *br_fdb_find_port(const struct net_device *br_dev,
 				    const unsigned char *addr,
 				    __u16 vid);
+bool br_port_flag_is_set(const struct net_device *dev, unsigned long flag);
 #else
 static inline struct net_device *
 br_fdb_find_port(const struct net_device *br_dev,
@@ -127,6 +128,11 @@ br_fdb_find_port(const struct net_device *br_dev,
 {
 	return NULL;
 }
+static inline bool
+br_port_flag_is_set(const struct net_device *dev, unsigned long flag)
+{
+	return false;
+}
 #endif
 
 #endif

net/bridge/br_if.c

@@ -741,3 +741,15 @@ void br_port_flags_change(struct net_bridge_port *p, unsigned long mask)
 	if (mask & BR_NEIGH_SUPPRESS)
 		br_recalculate_neigh_suppress_enabled(br);
 }
+
+bool br_port_flag_is_set(const struct net_device *dev, unsigned long flag)
+{
+	struct net_bridge_port *p;
+
+	p = br_port_get_rtnl_rcu(dev);
+	if (!p)
+		return false;
+
+	return p->flags & flag;
+}
+EXPORT_SYMBOL_GPL(br_port_flag_is_set);