bridge: add per-port broadcast flood flag

Support for l2 multicast flood control was added in commit b6cb5ac8331b
("net: bridge: add per-port multicast flood flag"). It allows broadcast
as it was introduced specifically for unknown multicast flood control.
But as broadcast is a special case of multicast, this may also need to
be disabled. For this purpose, introduce a flag to disable the flooding
of received l2 broadcasts. This approach is backwards compatible and
provides flexibility in filtering for the desired packet types.

Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Mike Manning <mmanning@brocade.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
index c5847dc..0c16866 100644
--- a/include/linux/if_bridge.h
+++ b/include/linux/if_bridge.h
@@ -48,6 +48,7 @@ struct br_ip_list {
 #define BR_MCAST_FLOOD		BIT(11)
 #define BR_MULTICAST_TO_UNICAST	BIT(12)
 #define BR_VLAN_TUNNEL		BIT(13)
+#define BR_BCAST_FLOOD		BIT(14)
 
 #define BR_DEFAULT_AGEING_TIME	(300 * HZ)