bridge: Validate that vlan is permitted on ingress

[~andy/linux] / net / bridge / br_vlan.c

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 209464ef5242729904dd1cbd7c77204bb16f7e50..8b4bcd8ff46e3e5ffde53a026b2ec7770722899c 100644 (file)
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -64,6 +64,31 @@ static void __vlan_flush(struct net_port_vlans *v)
        kfree_rcu(v, rcu);
 }
 
+/* Called under RCU */
+bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
+                       struct sk_buff *skb)
+{
+       u16 vid;
+
+       /* If VLAN filtering is disabled on the bridge, all packets are
+        * permitted.
+        */
+       if (!br->vlan_enabled)
+               return true;
+
+       /* If there are no vlan in the permitted list, all packets are
+        * rejected.
+        */
+       if (!v)
+               return false;
+
+       br_vlan_get_tag(skb, &vid);
+       if (test_bit(vid, v->vlan_bitmap))
+               return true;
+
+       return false;
+}
+
 /* Must be protected by RTNL */
 int br_vlan_add(struct net_bridge *br, u16 vid)
 {