net: bridge: Add/del switchdev object on host join/leave

When the host joins or leaves a multicast group, use switchdev to add
an object to the hardware to forward traffic for the group to the
host.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/switchdev.h

@@ -76,6 +76,7 @@ enum switchdev_obj_id {
 	SWITCHDEV_OBJ_ID_UNDEFINED,
 	SWITCHDEV_OBJ_ID_PORT_VLAN,
 	SWITCHDEV_OBJ_ID_PORT_MDB,
+	SWITCHDEV_OBJ_ID_HOST_MDB,
 };
 
 struct switchdev_obj {

net/bridge/br_mdb.c

@@ -292,6 +292,46 @@ err:
 	kfree(priv);
 }
 
+static void br_mdb_switchdev_host_port(struct net_device *dev,
+				       struct net_device *lower_dev,
+				       struct br_mdb_entry *entry, int type)
+{
+	struct switchdev_obj_port_mdb mdb = {
+		.obj = {
+			.id = SWITCHDEV_OBJ_ID_HOST_MDB,
+			.flags = SWITCHDEV_F_DEFER,
+		},
+		.vid = entry->vid,
+	};
+
+	if (entry->addr.proto == htons(ETH_P_IP))
+		ip_eth_mc_map(entry->addr.u.ip4, mdb.addr);
+#if IS_ENABLED(CONFIG_IPV6)
+	else
+		ipv6_eth_mc_map(&entry->addr.u.ip6, mdb.addr);
+#endif
+
+	mdb.obj.orig_dev = dev;
+	switch (type) {
+	case RTM_NEWMDB:
+		switchdev_port_obj_add(lower_dev, &mdb.obj);
+		break;
+	case RTM_DELMDB:
+		switchdev_port_obj_del(lower_dev, &mdb.obj);
+		break;
+	}
+}
+
+static void br_mdb_switchdev_host(struct net_device *dev,
+				  struct br_mdb_entry *entry, int type)
+{
+	struct net_device *lower_dev;
+	struct list_head *iter;
+
+	netdev_for_each_lower_dev(dev, lower_dev, iter)
+		br_mdb_switchdev_host_port(dev, lower_dev, entry, type);
+}
+
 static void __br_mdb_notify(struct net_device *dev, struct net_bridge_port *p,
 			    struct br_mdb_entry *entry, int type)
 {
@@ -331,6 +371,9 @@ static void __br_mdb_notify(struct net_device *dev, struct net_bridge_port *p,
 		switchdev_port_obj_del(port_dev, &mdb.obj);
 	}
 
+	if (!p)
+		br_mdb_switchdev_host(dev, entry, type);
+
 	skb = nlmsg_new(rtnl_mdb_nlmsg_size(), GFP_ATOMIC);
 	if (!skb)
 		goto errout;

net/switchdev/switchdev.c

@@ -345,6 +345,8 @@ static size_t switchdev_obj_size(const struct switchdev_obj *obj)
 		return sizeof(struct switchdev_obj_port_vlan);
 	case SWITCHDEV_OBJ_ID_PORT_MDB:
 		return sizeof(struct switchdev_obj_port_mdb);
+	case SWITCHDEV_OBJ_ID_HOST_MDB:
+		return sizeof(struct switchdev_obj_port_mdb);
 	default:
 		BUG();
 	}