net: bridge: mdb: move all port and bridge checks to br_mdb_add

To avoid doing duplicate device checks and searches (the same were done
in br_mdb_add and __br_mdb_add) pass the already found port to __br_mdb_add
and pull the bridge's netif_running and enabled multicast checks to
br_mdb_add. This would also simplify the future extack errors.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_mdb.c

@@ -775,31 +775,18 @@ static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
 }
 
 static int __br_mdb_add(struct net *net, struct net_bridge *br,
+			struct net_bridge_port *p,
 			struct br_mdb_entry *entry)
 {
 	struct br_ip ip;
-	struct net_device *dev;
-	struct net_bridge_port *p = NULL;
 	int ret;
 
-	if (!netif_running(br->dev) || !br_opt_get(br, BROPT_MULTICAST_ENABLED))
-		return -EINVAL;
-
-	if (entry->ifindex != br->dev->ifindex) {
-		dev = __dev_get_by_index(net, entry->ifindex);
-		if (!dev)
-			return -ENODEV;
-
-		p = br_port_get_rtnl(dev);
-		if (!p || p->br != br || p->state == BR_STATE_DISABLED)
-			return -EINVAL;
-	}
-
 	__mdb_entry_to_br_ip(entry, &ip);
 
 	spin_lock_bh(&br->multicast_lock);
 	ret = br_mdb_add_group(br, p, &ip, entry);
 	spin_unlock_bh(&br->multicast_lock);
+
 	return ret;
 }
 
@@ -821,6 +808,9 @@ static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
 
 	br = netdev_priv(dev);
 
+	if (!netif_running(br->dev) || !br_opt_get(br, BROPT_MULTICAST_ENABLED))
+		return -EINVAL;
+
 	if (entry->ifindex != br->dev->ifindex) {
 		pdev = __dev_get_by_index(net, entry->ifindex);
 		if (!pdev)
@@ -840,12 +830,12 @@ static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (br_vlan_enabled(br->dev) && vg && entry->vid == 0) {
 		list_for_each_entry(v, &vg->vlan_list, vlist) {
 			entry->vid = v->vid;
-			err = __br_mdb_add(net, br, entry);
+			err = __br_mdb_add(net, br, p, entry);
 			if (err)
 				break;
 		}
 	} else {
-		err = __br_mdb_add(net, br, entry);
+		err = __br_mdb_add(net, br, p, entry);
 	}
 
 	return err;