bridge: Don't use VID 0 and 4095 in vlan filtering

IEEE 802.1Q says that:
- VID 0 shall not be configured as a PVID, or configured in any Filtering
Database entry.
- VID 4095 shall not be configured as a PVID, or transmitted in a tag
header. This VID value may be used to indicate a wildcard match for the VID
in management operations or Filtering Database entries.
(See IEEE 802.1Q-2011 6.9.1 and Table 9-2)

Don't accept adding these VIDs in the vlan_filtering implementation.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Reviewed-by: Vlad Yasevich <vyasevic@redhat.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 49 insertions, 54 deletions

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index ffd5874f2592..33e8f23acddd 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -700,7 +700,7 @@ int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 
                 vid = nla_get_u16(tb[NDA_VLAN]);
 
-                if (vid >= VLAN_N_VID) {
+                if (!vid || vid >= VLAN_VID_MASK) {
                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
                                 vid);
                         return -EINVAL;
@@ -794,7 +794,7 @@ int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
 
                 vid = nla_get_u16(tb[NDA_VLAN]);
 
-                if (vid >= VLAN_N_VID) {
+                if (!vid || vid >= VLAN_VID_MASK) {
                         pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
                                 vid);
                         return -EINVAL;
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index e74ddc1c29a8..f75d92e4f96b 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -243,7 +243,7 @@ static int br_afspec(struct net_bridge *br,
 
                 vinfo = nla_data(tb[IFLA_BRIDGE_VLAN_INFO]);
 
-                if (vinfo->vid >= VLAN_N_VID)
+                if (!vinfo->vid || vinfo->vid >= VLAN_VID_MASK)
                         return -EINVAL;
 
                 switch (cmd) {
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 9a9ffe7e4019..21b6d217872b 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -45,37 +45,34 @@ static int __vlan_add(struct net_port_vlans *v, u16 vid, u16 flags)
                 return 0;
         }
 
-        if (vid) {
-                if (v->port_idx) {
-                        p = v->parent.port;
-                        br = p->br;
-                        dev = p->dev;
-                } else {
-                        br = v->parent.br;
-                        dev = br->dev;
-                }
-                ops = dev->netdev_ops;
-
-                if (p && (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)) {
-                        /* Add VLAN to the device filter if it is supported.
-                         * Stricly speaking, this is not necessary now, since
-                         * devices are made promiscuous by the bridge, but if
-                         * that ever changes this code will allow tagged
-                         * traffic to enter the bridge.
-                         */
-                        err = ops->ndo_vlan_rx_add_vid(dev, htons(ETH_P_8021Q),
-                                                       vid);
-                        if (err)
-                                return err;
-                }
-
-                err = br_fdb_insert(br, p, dev->dev_addr, vid);
-                if (err) {
-                        br_err(br, "failed insert local address into bridge "
-                               "forwarding table\n");
-                        goto out_filt;
-                }
+        if (v->port_idx) {
+                p = v->parent.port;
+                br = p->br;
+                dev = p->dev;
+        } else {
+                br = v->parent.br;
+                dev = br->dev;
+        }
+        ops = dev->netdev_ops;
+
+        if (p && (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)) {
+                /* Add VLAN to the device filter if it is supported.
+                 * Stricly speaking, this is not necessary now, since
+                 * devices are made promiscuous by the bridge, but if
+                 * that ever changes this code will allow tagged
+                 * traffic to enter the bridge.
+                 */
+                err = ops->ndo_vlan_rx_add_vid(dev, htons(ETH_P_8021Q),
+                                               vid);
+                if (err)
+                        return err;
+        }
 
+        err = br_fdb_insert(br, p, dev->dev_addr, vid);
+        if (err) {
+                br_err(br, "failed insert local address into bridge "
+                       "forwarding table\n");
+                goto out_filt;
         }
 
         set_bit(vid, v->vlan_bitmap);
@@ -98,7 +95,7 @@ static int __vlan_del(struct net_port_vlans *v, u16 vid)
         __vlan_delete_pvid(v, vid);
         clear_bit(vid, v->untagged_bitmap);
 
-        if (v->port_idx && vid) {
+        if (v->port_idx) {
                 struct net_device *dev = v->parent.port->dev;
                 const struct net_device_ops *ops = dev->netdev_ops;
 
@@ -248,7 +245,9 @@ bool br_allowed_egress(struct net_bridge *br,
         return false;
 }
 
-/* Must be protected by RTNL */
+/* Must be protected by RTNL.
+ * Must be called with vid in range from 1 to 4094 inclusive.
+ */
 int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
 {
         struct net_port_vlans *pv = NULL;
@@ -278,7 +277,9 @@ out:
         return err;
 }
 
-/* Must be protected by RTNL */
+/* Must be protected by RTNL.
+ * Must be called with vid in range from 1 to 4094 inclusive.
+ */
 int br_vlan_delete(struct net_bridge *br, u16 vid)
 {
         struct net_port_vlans *pv;
@@ -289,14 +290,9 @@ int br_vlan_delete(struct net_bridge *br, u16 vid)
         if (!pv)
                 return -EINVAL;
 
-        if (vid) {
-                /* If the VID !=0 remove fdb for this vid. VID 0 is special
-                 * in that it's the default and is always there in the fdb.
-                 */
-                spin_lock_bh(&br->hash_lock);
-                fdb_delete_by_addr(br, br->dev->dev_addr, vid);
-                spin_unlock_bh(&br->hash_lock);
-        }
+        spin_lock_bh(&br->hash_lock);
+        fdb_delete_by_addr(br, br->dev->dev_addr, vid);
+        spin_unlock_bh(&br->hash_lock);
 
         __vlan_del(pv, vid);
         return 0;
@@ -329,7 +325,9 @@ unlock:
         return 0;
 }
 
-/* Must be protected by RTNL */
+/* Must be protected by RTNL.
+ * Must be called with vid in range from 1 to 4094 inclusive.
+ */
 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
 {
         struct net_port_vlans *pv = NULL;
@@ -363,7 +361,9 @@ clean_up:
         return err;
 }
 
-/* Must be protected by RTNL */
+/* Must be protected by RTNL.
+ * Must be called with vid in range from 1 to 4094 inclusive.
+ */
 int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
 {
         struct net_port_vlans *pv;
@@ -374,14 +374,9 @@ int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
         if (!pv)
                 return -EINVAL;
 
-        if (vid) {
-                /* If the VID !=0 remove fdb for this vid. VID 0 is special
-                 * in that it's the default and is always there in the fdb.
-                 */
-                spin_lock_bh(&port->br->hash_lock);
-                fdb_delete_by_addr(port->br, port->dev->dev_addr, vid);
-                spin_unlock_bh(&port->br->hash_lock);
-        }
+        spin_lock_bh(&port->br->hash_lock);
+        fdb_delete_by_addr(port->br, port->dev->dev_addr, vid);
+        spin_unlock_bh(&port->br->hash_lock);
 
         return __vlan_del(pv, vid);
 }