1 files changed, 131 insertions, 17 deletions

diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
index 8846c5bcd075..95fa4af0e8dd 100644
--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -506,6 +506,134 @@ err:
 	kfree(priv);
 }
 
+static void br_switchdev_mdb_populate(struct switchdev_obj_port_mdb *mdb,
+				      const struct net_bridge_mdb_entry *mp)
+{
+	if (mp->addr.proto == htons(ETH_P_IP))
+		ip_eth_mc_map(mp->addr.dst.ip4, mdb->addr);
+#if IS_ENABLED(CONFIG_IPV6)
+	else if (mp->addr.proto == htons(ETH_P_IPV6))
+		ipv6_eth_mc_map(&mp->addr.dst.ip6, mdb->addr);
+#endif
+	else
+		ether_addr_copy(mdb->addr, mp->addr.dst.mac_addr);
+
+	mdb->vid = mp->addr.vid;
+}
+
+static int br_mdb_replay_one(struct notifier_block *nb, struct net_device *dev,
+			     struct switchdev_obj_port_mdb *mdb,
+			     struct netlink_ext_ack *extack)
+{
+	struct switchdev_notifier_port_obj_info obj_info = {
+		.info = {
+			.dev = dev,
+			.extack = extack,
+		},
+		.obj = &mdb->obj,
+	};
+	int err;
+
+	err = nb->notifier_call(nb, SWITCHDEV_PORT_OBJ_ADD, &obj_info);
+	return notifier_to_errno(err);
+}
+
+static int br_mdb_queue_one(struct list_head *mdb_list,
+			    enum switchdev_obj_id id,
+			    const struct net_bridge_mdb_entry *mp,
+			    struct net_device *orig_dev)
+{
+	struct switchdev_obj_port_mdb *mdb;
+
+	mdb = kzalloc(sizeof(*mdb), GFP_ATOMIC);
+	if (!mdb)
+		return -ENOMEM;
+
+	mdb->obj.id = id;
+	mdb->obj.orig_dev = orig_dev;
+	br_switchdev_mdb_populate(mdb, mp);
+	list_add_tail(&mdb->obj.list, mdb_list);
+
+	return 0;
+}
+
+int br_mdb_replay(struct net_device *br_dev, struct net_device *dev,
+		  struct notifier_block *nb, struct netlink_ext_ack *extack)
+{
+	struct net_bridge_mdb_entry *mp;
+	struct switchdev_obj *obj, *tmp;
+	struct net_bridge *br;
+	LIST_HEAD(mdb_list);
+	int err = 0;
+
+	ASSERT_RTNL();
+
+	if (!netif_is_bridge_master(br_dev) || !netif_is_bridge_port(dev))
+		return -EINVAL;
+
+	br = netdev_priv(br_dev);
+
+	if (!br_opt_get(br, BROPT_MULTICAST_ENABLED))
+		return 0;
+
+	/* We cannot walk over br->mdb_list protected just by the rtnl_mutex,
+	 * because the write-side protection is br->multicast_lock. But we
+	 * need to emulate the [ blocking ] calling context of a regular
+	 * switchdev event, so since both br->multicast_lock and RCU read side
+	 * critical sections are atomic, we have no choice but to pick the RCU
+	 * read side lock, queue up all our events, leave the critical section
+	 * and notify switchdev from blocking context.
+	 */
+	rcu_read_lock();
+
+	hlist_for_each_entry_rcu(mp, &br->mdb_list, mdb_node) {
+		struct net_bridge_port_group __rcu **pp;
+		struct net_bridge_port_group *p;
+
+		if (mp->host_joined) {
+			err = br_mdb_queue_one(&mdb_list,
+					       SWITCHDEV_OBJ_ID_HOST_MDB,
+					       mp, br_dev);
+			if (err) {
+				rcu_read_unlock();
+				goto out_free_mdb;
+			}
+		}
+
+		for (pp = &mp->ports; (p = rcu_dereference(*pp)) != NULL;
+		     pp = &p->next) {
+			if (p->key.port->dev != dev)
+				continue;
+
+			err = br_mdb_queue_one(&mdb_list,
+					       SWITCHDEV_OBJ_ID_PORT_MDB,
+					       mp, dev);
+			if (err) {
+				rcu_read_unlock();
+				goto out_free_mdb;
+			}
+		}
+	}
+
+	rcu_read_unlock();
+
+	list_for_each_entry(obj, &mdb_list, list) {
+		err = br_mdb_replay_one(nb, dev, SWITCHDEV_OBJ_PORT_MDB(obj),
+					extack);
+		if (err)
+			goto out_free_mdb;
+	}
+
+out_free_mdb:
+	list_for_each_entry_safe(obj, tmp, &mdb_list, list) {
+		list_del(&obj->list);
+		kfree(SWITCHDEV_OBJ_PORT_MDB(obj));
+	}
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(br_mdb_replay);
+
 static void br_mdb_switchdev_host_port(struct net_device *dev,
 				       struct net_device *lower_dev,
 				       struct net_bridge_mdb_entry *mp,
@@ -515,18 +643,12 @@ static void br_mdb_switchdev_host_port(struct net_device *dev,
 		.obj = {
 			.id = SWITCHDEV_OBJ_ID_HOST_MDB,
 			.flags = SWITCHDEV_F_DEFER,
+			.orig_dev = dev,
 		},
-		.vid = mp->addr.vid,
 	};
 
-	if (mp->addr.proto == htons(ETH_P_IP))
-		ip_eth_mc_map(mp->addr.dst.ip4, mdb.addr);
-#if IS_ENABLED(CONFIG_IPV6)
-	else
-		ipv6_eth_mc_map(&mp->addr.dst.ip6, mdb.addr);
-#endif
+	br_switchdev_mdb_populate(&mdb, mp);
 
-	mdb.obj.orig_dev = dev;
 	switch (type) {
 	case RTM_NEWMDB:
 		switchdev_port_obj_add(lower_dev, &mdb.obj, NULL);
@@ -558,21 +680,13 @@ void br_mdb_notify(struct net_device *dev,
 			.id = SWITCHDEV_OBJ_ID_PORT_MDB,
 			.flags = SWITCHDEV_F_DEFER,
 		},
-		.vid = mp->addr.vid,
 	};
 	struct net *net = dev_net(dev);
 	struct sk_buff *skb;
 	int err = -ENOBUFS;
 
 	if (pg) {
-		if (mp->addr.proto == htons(ETH_P_IP))
-			ip_eth_mc_map(mp->addr.dst.ip4, mdb.addr);
-#if IS_ENABLED(CONFIG_IPV6)
-		else if (mp->addr.proto == htons(ETH_P_IPV6))
-			ipv6_eth_mc_map(&mp->addr.dst.ip6, mdb.addr);
-#endif
-		else
-			ether_addr_copy(mdb.addr, mp->addr.dst.mac_addr);
+		br_switchdev_mdb_populate(&mdb, mp);
 
 		mdb.obj.orig_dev = pg->key.port->dev;
 		switch (type) {