bridge: add new brport flag LEARNING_SYNC

This policy flag controls syncing of learned FDB entries to bridge's FDB. If
on, FDB entries learned on bridge port device will be synced. If off, device
may still learn new FDB entries but they will not be synced with bridge's FDB.

Signed-off-by: Scott Feldman <[e-mail]>
Signed-off-by: Jiri Pirko <[e-mail]>
Acked-by: Roopa Prabhu <[e-mail]>
Acked-by: Jamal Hadi Salim <[e-mail]>
Acked-by: Andy Gospodarek <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/linux/if_bridge.h

···
 #define BR_AUTO_MASK		(BR_FLOOD | BR_LEARNING)
 #define BR_PROMISC		BIT(7)
 #define BR_PROXYARP		BIT(8)
+#define BR_LEARNING_SYNC	BIT(9)
 
 extern void brioctl_set(int (*ioctl_hook)(struct net *, unsigned int, void __user *));
 

include/uapi/linux/if_link.h

···
 	IFLA_BRPORT_LEARNING,	/* mac learning */
 	IFLA_BRPORT_UNICAST_FLOOD, /* flood unicast traffic */
 	IFLA_BRPORT_PROXYARP,	/* proxy ARP */
+	IFLA_BRPORT_LEARNING_SYNC, /* mac learning sync from device */
 	__IFLA_BRPORT_MAX
 };
 #define IFLA_BRPORT_MAX (__IFLA_BRPORT_MAX - 1)