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>

4 files changed, 41 insertions, 0 deletions

diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 02015a505d2a..35b0671f135d 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -31,6 +31,7 @@ static inline int should_deliver(const struct net_bridge_port *p,
                                  const struct sk_buff *skb)
 {
         return (((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
+                br_allowed_egress(p->br, nbp_get_vlan_info(p), skb) &&
                 p->state == BR_STATE_FORWARDING);
 }
 
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 4ef3f6b17bd0..787d7dad6b7e 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -35,6 +35,16 @@ static int br_pass_frame_up(struct sk_buff *skb)
         brstats->rx_bytes += skb->len;
         u64_stats_update_end(&brstats->syncp);
 
+        /* Bridge is just like any other port.  Make sure the
+         * packet is allowed except in promisc modue when someone
+         * may be running packet capture.
+         */
+        if (!(brdev->flags & IFF_PROMISC) &&
+            !br_allowed_egress(br, br_get_vlan_info(br), skb)) {
+                kfree_skb(skb);
+                return NET_RX_DROP;
+        }
+
         indev = skb->dev;
         skb->dev = brdev;
 
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index ed7c764ee9da..f0f24610d111 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -554,6 +554,9 @@ static inline void br_mdb_uninit(void)
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
 extern bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
                                struct sk_buff *skb);
+extern bool br_allowed_egress(struct net_bridge *br,
+                              const struct net_port_vlans *v,
+                              const struct sk_buff *skb);
 extern int br_vlan_add(struct net_bridge *br, u16 vid);
 extern int br_vlan_delete(struct net_bridge *br, u16 vid);
 extern void br_vlan_flush(struct net_bridge *br);
@@ -598,6 +601,13 @@ static inline bool br_allowed_ingress(struct net_bridge *br,
         return true;
 }
 
+static inline bool br_allowed_egress(struct net_bridge *br,
+                                     const struct net_port_vlans *v,
+                                     const struct sk_buff *skb)
+{
+        return true;
+}
+
 static inline int br_vlan_add(struct net_bridge *br, u16 vid)
 {
         return -EOPNOTSUPP;
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)
 {