bridge: add flags to distinguish permanent mdb entires

This patch adds a flag to each mdb entry, so that we can distinguish
permanent entries with temporary entries.

Cc: Herbert Xu <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: "David S. Miller" <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Amerigo Wang

include/uapi/linux/if_bridge.h

@@ -163,6 +163,9 @@ struct br_port_msg {
 
 struct br_mdb_entry {
 	__u32 ifindex;
+#define MDB_TEMPORARY 0
+#define MDB_PERMANENT 1
+	__u8 state;
 	struct {
 		union {
 			__be32	ip4;

net/bridge/br_mdb.c

@@ -83,6 +83,7 @@ static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
 				if (port) {
 					struct br_mdb_entry e;
 					e.ifindex = port->dev->ifindex;
+					e.state = p->state;
 					e.addr.u.ip4 = p->addr.u.ip4;
 #if IS_ENABLED(CONFIG_IPV6)
 					e.addr.u.ip6 = p->addr.u.ip6;
@@ -253,6 +254,8 @@ static bool is_valid_mdb_entry(struct br_mdb_entry *entry)
 #endif
 	} else
 		return false;
+	if (entry->state != MDB_PERMANENT && entry->state != MDB_TEMPORARY)
+		return false;
 
 	return true;
 }
@@ -310,7 +313,7 @@ static int br_mdb_parse(struct sk_buff *skb, struct nlmsghdr *nlh,
 }
 
 static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
-			    struct br_ip *group)
+			    struct br_ip *group, unsigned char state)
 {
 	struct net_bridge_mdb_entry *mp;
 	struct net_bridge_port_group *p;
@@ -336,7 +339,7 @@ static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
 			break;
 	}
 
-	p = br_multicast_new_port_group(port, group, *pp);
+	p = br_multicast_new_port_group(port, group, *pp, state);
 	if (unlikely(!p))
 		return -ENOMEM;
 	rcu_assign_pointer(*pp, p);
@@ -373,7 +376,7 @@ static int __br_mdb_add(struct net *net, struct net_bridge *br,
 #endif
 
 	spin_lock_bh(&br->multicast_lock);
-	ret = br_mdb_add_group(br, p, &ip);
+	ret = br_mdb_add_group(br, p, &ip, entry->state);
 	spin_unlock_bh(&br->multicast_lock);
 	return ret;
 }

net/bridge/br_multicast.c

@@ -279,7 +279,7 @@ static void br_multicast_port_group_expired(unsigned long data)
 
 	spin_lock(&br->multicast_lock);
 	if (!netif_running(br->dev) || timer_pending(&pg->timer) ||
-	    hlist_unhashed(&pg->mglist))
+	    hlist_unhashed(&pg->mglist) || pg->state & MDB_PERMANENT)
 		goto out;
 
 	br_multicast_del_pg(br, pg);
@@ -622,7 +622,8 @@ struct net_bridge_mdb_entry *br_multicast_new_group(struct net_bridge *br,
 struct net_bridge_port_group *br_multicast_new_port_group(
 			struct net_bridge_port *port,
 			struct br_ip *group,
-			struct net_bridge_port_group __rcu *next)
+			struct net_bridge_port_group __rcu *next,
+			unsigned char state)
 {
 	struct net_bridge_port_group *p;
 
@@ -632,6 +633,7 @@ struct net_bridge_port_group *br_multicast_new_port_group(
 
 	p->addr = *group;
 	p->port = port;
+	p->state = state;
 	rcu_assign_pointer(p->next, next);
 	hlist_add_head(&p->mglist, &port->mglist);
 	setup_timer(&p->timer, br_multicast_port_group_expired,
@@ -674,7 +676,7 @@ static int br_multicast_add_group(struct net_bridge *br,
 			break;
 	}
 
-	p = br_multicast_new_port_group(port, group, *pp);
+	p = br_multicast_new_port_group(port, group, *pp, MDB_TEMPORARY);
 	if (unlikely(!p))
 		goto err;
 	rcu_assign_pointer(*pp, p);

net/bridge/br_private.h

@@ -83,6 +83,7 @@ struct net_bridge_port_group {
 	struct rcu_head			rcu;
 	struct timer_list		timer;
 	struct br_ip			addr;
+	unsigned char			state;
 };
 
 struct net_bridge_mdb_entry
@@ -443,7 +444,8 @@ extern void br_multicast_free_pg(struct rcu_head *head);
 extern struct net_bridge_port_group *br_multicast_new_port_group(
 				struct net_bridge_port *port,
 				struct br_ip *group,
-				struct net_bridge_port_group *next);
+				struct net_bridge_port_group *next,
+				unsigned char state);
 extern void br_mdb_init(void);
 extern void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
 			  struct br_ip *group, int type);