bridge: allow adding of fdb entries pointing to the bridge device

This patch enables adding of fdb entries pointing to the bridge device.
This can be used to propagate mac address of vlan interfaces
configured on top of the vlan filtering bridge.

Before:
$bridge fdb add 44:38:39:00:27:9f dev bridge
RTNETLINK answers: Invalid argument

After:
$bridge fdb add 44:38:39:00:27:9f dev bridge
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_fdb.c

@@ -608,13 +608,14 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 	}
 }
 
-static int fdb_to_nud(const struct net_bridge_fdb_entry *fdb)
+static int fdb_to_nud(const struct net_bridge *br,
+		      const struct net_bridge_fdb_entry *fdb)
 {
 	if (fdb->is_local)
 		return NUD_PERMANENT;
 	else if (fdb->is_static)
 		return NUD_NOARP;
-	else if (has_expired(fdb->dst->br, fdb))
+	else if (has_expired(br, fdb))
 		return NUD_STALE;
 	else
 		return NUD_REACHABLE;
@@ -640,7 +641,7 @@ static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
 	ndm->ndm_flags	 = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 0;
 	ndm->ndm_type	 = 0;
 	ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
-	ndm->ndm_state   = fdb_to_nud(fdb);
+	ndm->ndm_state   = fdb_to_nud(br, fdb);
 
 	if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
 		goto nla_put_failure;
@@ -785,7 +786,7 @@ static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
 		}
 	}
 
-	if (fdb_to_nud(fdb) != state) {
+	if (fdb_to_nud(br, fdb) != state) {
 		if (state & NUD_PERMANENT) {
 			fdb->is_local = 1;
 			if (!fdb->is_static) {
@@ -846,8 +847,9 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 	       const unsigned char *addr, u16 vid, u16 nlh_flags)
 {
 	struct net_bridge_vlan_group *vg;
-	struct net_bridge_port *p;
+	struct net_bridge_port *p = NULL;
 	struct net_bridge_vlan *v;
+	struct net_bridge *br = NULL;
 	int err = 0;
 
 	if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
@@ -860,25 +862,35 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 		return -EINVAL;
 	}
 
+	if (dev->priv_flags & IFF_EBRIDGE) {
+		br = netdev_priv(dev);
+		vg = br_vlan_group(br);
+	} else {
 		p = br_port_get_rtnl(dev);
-	if (p == NULL) {
+		if (!p) {
 			pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
 				dev->name);
 			return -EINVAL;
 		}
-
 		vg = nbp_vlan_group(p);
+	}
+
 	if (vid) {
 		v = br_vlan_find(vg, vid);
-		if (!v) {
-			pr_info("bridge: RTM_NEWNEIGH with unconfigured "
-				"vlan %d on port %s\n", vid, dev->name);
+		if (!v || !br_vlan_should_use(v)) {
+			pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 			return -EINVAL;
 		}
 
 		/* VID was specified, so use it. */
+		if (dev->priv_flags & IFF_EBRIDGE)
+			err = br_fdb_insert(br, NULL, addr, vid);
+		else
 			err = __br_fdb_add(ndm, p, addr, nlh_flags, vid);
 	} else {
+		if (dev->priv_flags & IFF_EBRIDGE)
+			err = br_fdb_insert(br, NULL, addr, 0);
+		else
 			err = __br_fdb_add(ndm, p, addr, nlh_flags, 0);
 		if (err || !vg || !vg->num_vlans)
 			goto out;
@@ -888,7 +900,13 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 		 * vlan on this port.
 		 */
 		list_for_each_entry(v, &vg->vlan_list, vlist) {
-			err = __br_fdb_add(ndm, p, addr, nlh_flags, v->vid);
+			if (!br_vlan_should_use(v))
+				continue;
+			if (dev->priv_flags & IFF_EBRIDGE)
+				err = br_fdb_insert(br, NULL, addr, v->vid);
+			else
+				err = __br_fdb_add(ndm, p, addr, nlh_flags,
+						   v->vid);
 			if (err)
 				goto out;
 		}
@@ -898,6 +916,32 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 	return err;
 }
 
+static int fdb_delete_by_addr(struct net_bridge *br, const u8 *addr,
+			      u16 vid)
+{
+	struct hlist_head *head = &br->hash[br_mac_hash(addr, vid)];
+	struct net_bridge_fdb_entry *fdb;
+
+	fdb = fdb_find(head, addr, vid);
+	if (!fdb)
+		return -ENOENT;
+
+	fdb_delete(br, fdb);
+	return 0;
+}
+
+static int __br_fdb_delete_by_addr(struct net_bridge *br,
+				   const unsigned char *addr, u16 vid)
+{
+	int err;
+
+	spin_lock_bh(&br->hash_lock);
+	err = fdb_delete_by_addr(br, addr, vid);
+	spin_unlock_bh(&br->hash_lock);
+
+	return err;
+}
+
 static int fdb_delete_by_addr_and_port(struct net_bridge_port *p,
 				       const u8 *addr, u16 vlan)
 {
@@ -931,36 +975,54 @@ int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 		  const unsigned char *addr, u16 vid)
 {
 	struct net_bridge_vlan_group *vg;
-	struct net_bridge_port *p;
+	struct net_bridge_port *p = NULL;
 	struct net_bridge_vlan *v;
+	struct net_bridge *br = NULL;
 	int err;
 
+	if (dev->priv_flags & IFF_EBRIDGE) {
+		br = netdev_priv(dev);
+		vg = br_vlan_group(br);
+	} else {
 		p = br_port_get_rtnl(dev);
-	if (p == NULL) {
+		if (!p) {
 			pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
 				dev->name);
 			return -EINVAL;
 		}
-
 		vg = nbp_vlan_group(p);
+	}
+
 	if (vid) {
 		v = br_vlan_find(vg, vid);
 		if (!v) {
-			pr_info("bridge: RTM_DELNEIGH with unconfigured "
-				"vlan %d on port %s\n", vid, dev->name);
+			pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
 			return -EINVAL;
 		}
 
+		if (dev->priv_flags & IFF_EBRIDGE)
+			err = __br_fdb_delete_by_addr(br, addr, vid);
+		else
 			err = __br_fdb_delete(p, addr, vid);
 	} else {
 		err = -ENOENT;
+		if (dev->priv_flags & IFF_EBRIDGE)
+			err = __br_fdb_delete_by_addr(br, addr, 0);
+		else
 			err &= __br_fdb_delete(p, addr, 0);
+
 		if (!vg || !vg->num_vlans)
 			goto out;
 
-		list_for_each_entry(v, &vg->vlan_list, vlist)
+		list_for_each_entry(v, &vg->vlan_list, vlist) {
+			if (!br_vlan_should_use(v))
+				continue;
+			if (dev->priv_flags & IFF_EBRIDGE)
+				err = __br_fdb_delete_by_addr(br, addr, v->vid);
+			else
 				err &= __br_fdb_delete(p, addr, v->vid);
 		}
+	}
 out:
 	return err;
 }

net/bridge/br_vlan.c

@@ -564,6 +564,7 @@ int br_vlan_delete(struct net_bridge *br, u16 vid)
 		return -ENOENT;
 
 	br_fdb_find_delete_local(br, NULL, br->dev->dev_addr, vid);
+	br_fdb_delete_by_port(br, NULL, vid, 0);
 
 	return __vlan_del(v);
 }