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/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 902af6b..48fb174 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -183,13 +183,23 @@ void br_flood(struct net_bridge *br, struct sk_buff *skb,
 	struct net_bridge_port *p;
 
 	list_for_each_entry_rcu(p, &br->port_list, list) {
-		/* Do not flood unicast traffic to ports that turn it off */
-		if (pkt_type == BR_PKT_UNICAST && !(p->flags & BR_FLOOD))
-			continue;
-		/* Do not flood if mc off, except for traffic we originate */
-		if (pkt_type == BR_PKT_MULTICAST &&
-		    !(p->flags & BR_MCAST_FLOOD) && skb->dev != br->dev)
-			continue;
+		/* Do not flood unicast traffic to ports that turn it off, nor
+		 * other traffic if flood off, except for traffic we originate
+		 */
+		switch (pkt_type) {
+		case BR_PKT_UNICAST:
+			if (!(p->flags & BR_FLOOD))
+				continue;
+			break;
+		case BR_PKT_MULTICAST:
+			if (!(p->flags & BR_MCAST_FLOOD) && skb->dev != br->dev)
+				continue;
+			break;
+		case BR_PKT_BROADCAST:
+			if (!(p->flags & BR_BCAST_FLOOD) && skb->dev != br->dev)
+				continue;
+			break;
+		}
 
 		/* Do not flood to ports that enable proxy ARP */
 		if (p->flags & BR_PROXYARP)