net: bridge: mdb: allow add/delete for host-joined groups

Currently this is needed only for user-space compatibility, so similar
object adds/deletes as the dumped ones would succeed. Later it can be
used for L2 mcast MAC add/delete.

v3: fix compiler warning (DaveM)
v2: don't send a notification when used from user-space, arm the group
    timer if no ports are left after host entry del
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_mdb.c

@@ -616,6 +616,19 @@ static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
 			return err;
 	}
 
+	/* host join */
+	if (!port) {
+		/* don't allow any flags for host-joined groups */
+		if (state)
+			return -EINVAL;
+		if (mp->host_joined)
+			return -EEXIST;
+
+		br_multicast_host_join(mp, false);
+
+		return 0;
+	}
+
 	for (pp = &mp->ports;
 	     (p = mlock_dereference(*pp, br)) != NULL;
 	     pp = &p->next) {
@@ -640,19 +653,21 @@ static int __br_mdb_add(struct net *net, struct net_bridge *br,
 {
 	struct br_ip ip;
 	struct net_device *dev;
-	struct net_bridge_port *p;
+	struct net_bridge_port *p = NULL;
 	int ret;
 
 	if (!netif_running(br->dev) || !br_opt_get(br, BROPT_MULTICAST_ENABLED))
 		return -EINVAL;
 
-	dev = __dev_get_by_index(net, entry->ifindex);
-	if (!dev)
-		return -ENODEV;
+	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;
+		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);
 
@@ -667,9 +682,9 @@ static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
 {
 	struct net *net = sock_net(skb->sk);
 	struct net_bridge_vlan_group *vg;
+	struct net_bridge_port *p = NULL;
 	struct net_device *dev, *pdev;
 	struct br_mdb_entry *entry;
-	struct net_bridge_port *p;
 	struct net_bridge_vlan *v;
 	struct net_bridge *br;
 	int err;
@@ -680,15 +695,19 @@ static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
 
 	br = netdev_priv(dev);
 
-	pdev = __dev_get_by_index(net, entry->ifindex);
-	if (!pdev)
-		return -ENODEV;
+	if (entry->ifindex != br->dev->ifindex) {
+		pdev = __dev_get_by_index(net, entry->ifindex);
+		if (!pdev)
+			return -ENODEV;
 
-	p = br_port_get_rtnl(pdev);
-	if (!p || p->br != br || p->state == BR_STATE_DISABLED)
-		return -EINVAL;
+		p = br_port_get_rtnl(pdev);
+		if (!p || p->br != br || p->state == BR_STATE_DISABLED)
+			return -EINVAL;
+		vg = nbp_vlan_group(p);
+	} else {
+		vg = br_vlan_group(br);
+	}
 
-	vg = nbp_vlan_group(p);
 	/* If vlan filtering is enabled and VLAN is not specified
 	 * install mdb entry on all vlans configured on the port.
 	 */
@@ -727,6 +746,15 @@ static int __br_mdb_del(struct net_bridge *br, struct br_mdb_entry *entry)
 	if (!mp)
 		goto unlock;
 
+	/* host leave */
+	if (entry->ifindex == mp->br->dev->ifindex && mp->host_joined) {
+		br_multicast_host_leave(mp, false);
+		err = 0;
+		if (!mp->ports && netif_running(br->dev))
+			mod_timer(&mp->timer, jiffies);
+		goto unlock;
+	}
+
 	for (pp = &mp->ports;
 	     (p = mlock_dereference(*pp, br)) != NULL;
 	     pp = &p->next) {
@@ -759,9 +787,9 @@ static int br_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh,
 {
 	struct net *net = sock_net(skb->sk);
 	struct net_bridge_vlan_group *vg;
+	struct net_bridge_port *p = NULL;
 	struct net_device *dev, *pdev;
 	struct br_mdb_entry *entry;
-	struct net_bridge_port *p;
 	struct net_bridge_vlan *v;
 	struct net_bridge *br;
 	int err;
@@ -772,15 +800,19 @@ static int br_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh,
 
 	br = netdev_priv(dev);
 
-	pdev = __dev_get_by_index(net, entry->ifindex);
-	if (!pdev)
-		return -ENODEV;
+	if (entry->ifindex != br->dev->ifindex) {
+		pdev = __dev_get_by_index(net, entry->ifindex);
+		if (!pdev)
+			return -ENODEV;
 
-	p = br_port_get_rtnl(pdev);
-	if (!p || p->br != br || p->state == BR_STATE_DISABLED)
-		return -EINVAL;
+		p = br_port_get_rtnl(pdev);
+		if (!p || p->br != br || p->state == BR_STATE_DISABLED)
+			return -EINVAL;
+		vg = nbp_vlan_group(p);
+	} else {
+		vg = br_vlan_group(br);
+	}
 
-	vg = nbp_vlan_group(p);
 	/* If vlan filtering is enabled and VLAN is not specified
 	 * delete mdb entry on all vlans configured on the port.
 	 */

net/bridge/br_multicast.c

@@ -148,8 +148,7 @@ static void br_multicast_group_expired(struct timer_list *t)
 	if (!netif_running(br->dev) || timer_pending(&mp->timer))
 		goto out;
 
-	mp->host_joined = false;
-	br_mdb_notify(br->dev, NULL, &mp->addr, RTM_DELMDB, 0);
+	br_multicast_host_leave(mp, true);
 
 	if (mp->ports)
 		goto out;
@@ -512,6 +511,27 @@ static bool br_port_group_equal(struct net_bridge_port_group *p,
 	return ether_addr_equal(src, p->eth_addr);
 }
 
+void br_multicast_host_join(struct net_bridge_mdb_entry *mp, bool notify)
+{
+	if (!mp->host_joined) {
+		mp->host_joined = true;
+		if (notify)
+			br_mdb_notify(mp->br->dev, NULL, &mp->addr,
+				      RTM_NEWMDB, 0);
+	}
+	mod_timer(&mp->timer, jiffies + mp->br->multicast_membership_interval);
+}
+
+void br_multicast_host_leave(struct net_bridge_mdb_entry *mp, bool notify)
+{
+	if (!mp->host_joined)
+		return;
+
+	mp->host_joined = false;
+	if (notify)
+		br_mdb_notify(mp->br->dev, NULL, &mp->addr, RTM_DELMDB, 0);
+}
+
 static int br_multicast_add_group(struct net_bridge *br,
 				  struct net_bridge_port *port,
 				  struct br_ip *group,
@@ -534,11 +554,7 @@ static int br_multicast_add_group(struct net_bridge *br,
 		goto err;
 
 	if (!port) {
-		if (!mp->host_joined) {
-			mp->host_joined = true;
-			br_mdb_notify(br->dev, NULL, &mp->addr, RTM_NEWMDB, 0);
-		}
-		mod_timer(&mp->timer, now + br->multicast_membership_interval);
+		br_multicast_host_join(mp, true);
 		goto out;
 	}
 

net/bridge/br_private.h

@@ -702,6 +702,8 @@ void br_multicast_get_stats(const struct net_bridge *br,
 			    struct br_mcast_stats *dest);
 void br_mdb_init(void);
 void br_mdb_uninit(void);
+void br_multicast_host_join(struct net_bridge_mdb_entry *mp, bool notify);
+void br_multicast_host_leave(struct net_bridge_mdb_entry *mp, bool notify);
 
 #define mlock_dereference(X, br) \
 	rcu_dereference_protected(X, lockdep_is_held(&br->multicast_lock))