bridge: Prepare for 802.1ad vlan filtering support

This enables a bridge to have vlan protocol informantion and allows vlan
tag manipulation (retrieve, insert and remove tags) according to the vlan
protocol.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 51 insertions, 12 deletions

diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 82a410a5ef7e..1b797c42ef5f 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -388,4 +388,5 @@ void br_dev_setup(struct net_device *dev)
         br_netfilter_rtable_init(br);
         br_stp_timer_init(br);
         br_multicast_init(br);
+        br_vlan_init(br);
 }
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 8346e9504cdb..13e570e8b0fc 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -294,6 +294,7 @@ struct net_bridge
         u32                             auto_cnt;
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
         u8                              vlan_enabled;
+        __be16                          vlan_proto;
         struct net_port_vlans __rcu     *vlan_info;
 #endif
 };
@@ -594,6 +595,7 @@ int br_vlan_delete(struct net_bridge *br, u16 vid);
 void br_vlan_flush(struct net_bridge *br);
 bool br_vlan_find(struct net_bridge *br, u16 vid);
 int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val);
+void br_vlan_init(struct net_bridge *br);
 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags);
 int nbp_vlan_delete(struct net_bridge_port *port, u16 vid);
 void nbp_vlan_flush(struct net_bridge_port *port);
@@ -689,6 +691,10 @@ static inline bool br_vlan_find(struct net_bridge *br, u16 vid)
         return false;
 }
 
+static inline void br_vlan_init(struct net_bridge *br)
+{
+}
+
 static inline int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
 {
         return -EOPNOTSUPP;
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index fcc95390f862..63bd98137a42 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -60,7 +60,7 @@ static int __vlan_add(struct net_port_vlans *v, u16 vid, u16 flags)
                  * that ever changes this code will allow tagged
                  * traffic to enter the bridge.
                  */
-                err = vlan_vid_add(dev, htons(ETH_P_8021Q), vid);
+                err = vlan_vid_add(dev, br->vlan_proto, vid);
                 if (err)
                         return err;
         }
@@ -80,7 +80,7 @@ static int __vlan_add(struct net_port_vlans *v, u16 vid, u16 flags)
 
 out_filt:
         if (p)
-                vlan_vid_del(dev, htons(ETH_P_8021Q), vid);
+                vlan_vid_del(dev, br->vlan_proto, vid);
         return err;
 }
 
@@ -92,8 +92,10 @@ 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)
-                vlan_vid_del(v->parent.port->dev, htons(ETH_P_8021Q), vid);
+        if (v->port_idx) {
+                struct net_bridge_port *p = v->parent.port;
+                vlan_vid_del(p->dev, p->br->vlan_proto, vid);
+        }
 
         clear_bit(vid, v->vlan_bitmap);
         v->num_vlans--;
@@ -158,7 +160,8 @@ out:
 bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
                         struct sk_buff *skb, u16 *vid)
 {
-        int err;
+        bool tagged;
+        __be16 proto;
 
         /* If VLAN filtering is disabled on the bridge, all packets are
          * permitted.
@@ -172,19 +175,41 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
         if (!v)
                 goto drop;
 
+        proto = br->vlan_proto;
+
         /* If vlan tx offload is disabled on bridge device and frame was
          * sent from vlan device on the bridge device, it does not have
          * HW accelerated vlan tag.
          */
         if (unlikely(!vlan_tx_tag_present(skb) &&
-                     (skb->protocol == htons(ETH_P_8021Q) ||
-                      skb->protocol == htons(ETH_P_8021AD)))) {
+                     skb->protocol == proto)) {
                 skb = vlan_untag(skb);
                 if (unlikely(!skb))
                         return false;
         }
 
-        err = br_vlan_get_tag(skb, vid);
+        if (!br_vlan_get_tag(skb, vid)) {
+                /* Tagged frame */
+                if (skb->vlan_proto != proto) {
+                        /* Protocol-mismatch, empty out vlan_tci for new tag */
+                        skb_push(skb, ETH_HLEN);
+                        skb = __vlan_put_tag(skb, skb->vlan_proto,
+                                             vlan_tx_tag_get(skb));
+                        if (unlikely(!skb))
+                                return false;
+
+                        skb_pull(skb, ETH_HLEN);
+                        skb_reset_mac_len(skb);
+                        *vid = 0;
+                        tagged = false;
+                } else {
+                        tagged = true;
+                }
+        } else {
+                /* Untagged frame */
+                tagged = false;
+        }
+
         if (!*vid) {
                 u16 pvid = br_get_pvid(v);
 
@@ -199,9 +224,9 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
                  * ingress frame is considered to belong to this vlan.
                  */
                 *vid = pvid;
-                if (likely(err))
+                if (likely(!tagged))
                         /* Untagged Frame. */
-                        __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), pvid);
+                        __vlan_hwaccel_put_tag(skb, proto, pvid);
                 else
                         /* Priority-tagged Frame.
                          * At this point, We know that skb->vlan_tci had
@@ -254,7 +279,9 @@ bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid)
         if (!v)
                 return false;
 
-        br_vlan_get_tag(skb, vid);
+        if (!br_vlan_get_tag(skb, vid) && skb->vlan_proto != br->vlan_proto)
+                *vid = 0;
+
         if (!*vid) {
                 *vid = br_get_pvid(v);
                 if (*vid == VLAN_N_VID)
@@ -367,6 +394,11 @@ unlock:
         return 0;
 }
 
+void br_vlan_init(struct net_bridge *br)
+{
+        br->vlan_proto = htons(ETH_P_8021Q);
+}
+
 /* Must be protected by RTNL.
  * Must be called with vid in range from 1 to 4094 inclusive.
  */
@@ -433,7 +465,7 @@ void nbp_vlan_flush(struct net_bridge_port *port)
                 return;
 
         for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
-                vlan_vid_del(port->dev, htons(ETH_P_8021Q), vid);
+                vlan_vid_del(port->dev, port->br->vlan_proto, vid);
 
         __vlan_flush(pv);
 }