net/8021q: Implement Multiple VLAN Registration Protocol (MVRP)

Initial implementation of the Multiple VLAN Registration Protocol
(MVRP) from IEEE 802.1Q-2011, based on the existing implementation
of the GARP VLAN Registration Protocol (GVRP).

Signed-off-by: David Ward <david.ward@ll.mit.edu>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 09f9108..34df5b3 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -261,7 +261,7 @@
 	u32 old_flags = vlan->flags;
 
 	if (mask & ~(VLAN_FLAG_REORDER_HDR | VLAN_FLAG_GVRP |
-		     VLAN_FLAG_LOOSE_BINDING))
+		     VLAN_FLAG_LOOSE_BINDING | VLAN_FLAG_MVRP))
 		return -EINVAL;
 
 	vlan->flags = (old_flags & ~mask) | (flags & mask);
@@ -272,6 +272,13 @@
 		else
 			vlan_gvrp_request_leave(dev);
 	}
+
+	if (netif_running(dev) && (vlan->flags ^ old_flags) & VLAN_FLAG_MVRP) {
+		if (vlan->flags & VLAN_FLAG_MVRP)
+			vlan_mvrp_request_join(dev);
+		else
+			vlan_mvrp_request_leave(dev);
+	}
 	return 0;
 }
 
@@ -312,6 +319,9 @@
 	if (vlan->flags & VLAN_FLAG_GVRP)
 		vlan_gvrp_request_join(dev);
 
+	if (vlan->flags & VLAN_FLAG_MVRP)
+		vlan_mvrp_request_join(dev);
+
 	if (netif_carrier_ok(real_dev))
 		netif_carrier_on(dev);
 	return 0;