net: bridge: mcast: delete expired port groups without srcs

If an expired port group is in EXCLUDE mode, then we have to turn it
into INCLUDE mode, remove all srcs with zero timer and finally remove
the group itself if there are no more srcs with an active timer.
For IGMPv2 use there would be no sources, so this will reduce to just
removing the group as before.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/bridge/br_multicast.c

@@ -222,15 +222,34 @@ static void br_multicast_find_del_pg(struct net_bridge *br,
 static void br_multicast_port_group_expired(struct timer_list *t)
 {
 	struct net_bridge_port_group *pg = from_timer(pg, t, timer);
+	struct net_bridge_group_src *src_ent;
 	struct net_bridge *br = pg->port->br;
+	struct hlist_node *tmp;
+	bool changed;
 
 	spin_lock(&br->multicast_lock);
 	if (!netif_running(br->dev) || timer_pending(&pg->timer) ||
 	    hlist_unhashed(&pg->mglist) || pg->flags & MDB_PG_FLAGS_PERMANENT)
 		goto out;
 
+	changed = !!(pg->filter_mode == MCAST_EXCLUDE);
+	pg->filter_mode = MCAST_INCLUDE;
+	hlist_for_each_entry_safe(src_ent, tmp, &pg->src_list, node) {
+		if (!timer_pending(&src_ent->timer)) {
+			br_multicast_del_group_src(src_ent);
+			changed = true;
+		}
+	}
+
+	if (hlist_empty(&pg->src_list)) {
 		br_multicast_find_del_pg(br, pg);
+	} else if (changed) {
+		struct net_bridge_mdb_entry *mp = br_mdb_ip_get(br, &pg->addr);
 
+		if (WARN_ON(!mp))
+			goto out;
+		br_mdb_notify(br->dev, mp, pg, RTM_NEWMDB);
+	}
 out:
 	spin_unlock(&br->multicast_lock);
 }