bridge: Verify that a vlan is allowed to egress on given port

When bridge forwards a frame, make sure that a frame is allowed
to egress on that port.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 20 insertions, 0 deletions

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 8b4bcd8ff46e..d8690bfe63d4 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -89,6 +89,26 @@ bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
         return false;
 }
 
+/* Called under RCU. */
+bool br_allowed_egress(struct net_bridge *br,
+                       const struct net_port_vlans *v,
+                       const struct sk_buff *skb)
+{
+        u16 vid;
+
+        if (!br->vlan_enabled)
+                return true;
+
+        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)
 {