bridge: Apply the PVID to priority-tagged frames

IEEE 802.1Q says that when we receive priority-tagged (VID 0) frames
use the PVID for the port as its VID.
(See IEEE 802.1Q-2011 6.9.1 and Table 9-2)

Apply the PVID to not only untagged frames but also priority-tagged frames.

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

1 files changed, 20 insertions, 7 deletions

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 21b6d217872b..5a9c44a0c306 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -189,6 +189,8 @@ out:
 bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
                         struct sk_buff *skb, u16 *vid)
 {
+        int err;
+
         /* If VLAN filtering is disabled on the bridge, all packets are
          * permitted.
          */
@@ -201,20 +203,31 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
         if (!v)
                 return false;
 
-        if (br_vlan_get_tag(skb, vid)) {
+        err = br_vlan_get_tag(skb, vid);
+        if (!*vid) {
                 u16 pvid = br_get_pvid(v);
 
-                /* Frame did not have a tag.  See if pvid is set
-                 * on this port.  That tells us which vlan untagged
-                 * traffic belongs to.
+                /* Frame had a tag with VID 0 or did not have a tag.
+                 * See if pvid is set on this port.  That tells us which
+                 * vlan untagged or priority-tagged traffic belongs to.
                  */
                 if (pvid == VLAN_N_VID)
                         return false;
 
-                /* PVID is set on this port.  Any untagged ingress
-                 * frame is considered to belong to this vlan.
+                /* PVID is set on this port.  Any untagged or priority-tagged
+                 * ingress frame is considered to belong to this vlan.
                  */
-                __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), pvid);
+                if (likely(err))
+                        /* Untagged Frame. */
+                        __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), pvid);
+                else
+                        /* Priority-tagged Frame.
+                         * At this point, We know that skb->vlan_tci had
+                         * VLAN_TAG_PRESENT bit and its VID field was 0x000.
+                         * We update only VID field and preserve PCP field.
+                         */
+                        skb->vlan_tci |= pvid;
+
                 return true;
         }