bridge: Add vlan filtering infrastructure

Adds an optional infrustructure component to bridge that would allow
native vlan filtering in the bridge.  Each bridge port (as well
as the bridge device) now get a VLAN bitmap.  Each bit in the bitmap
is associated with a vlan id.  This way if the bit corresponding to
the vid is set in the bitmap that the packet with vid is allowed to
enter and exit the port.

Write access the bitmap is protected by RTNL and read access
protected by RCU.

Vlan functionality is disabled by default.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 06e85d9..1f3b309 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -18,6 +18,7 @@
 #include <linux/netpoll.h>
 #include <linux/u64_stats_sync.h>
 #include <net/route.h>
+#include <linux/if_vlan.h>
 
 #define BR_HASH_BITS 8
 #define BR_HASH_SIZE (1 << BR_HASH_BITS)
@@ -26,6 +27,7 @@
 
 #define BR_PORT_BITS	10
 #define BR_MAX_PORTS	(1<<BR_PORT_BITS)
+#define BR_VLAN_BITMAP_LEN	BITS_TO_LONGS(VLAN_N_VID)
 
 #define BR_VERSION	"2.3"
 
@@ -63,6 +65,16 @@
 	__be16		proto;
 };
 
+struct net_port_vlans {
+	u16				port_idx;
+	union {
+		struct net_bridge_port		*port;
+		struct net_bridge		*br;
+	}				parent;
+	struct rcu_head			rcu;
+	unsigned long			vlan_bitmap[BR_VLAN_BITMAP_LEN];
+};
+
 struct net_bridge_fdb_entry
 {
 	struct hlist_node		hlist;
@@ -156,6 +168,9 @@
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	struct netpoll			*np;
 #endif
+#ifdef CONFIG_BRIDGE_VLAN_FILTERING
+	struct net_port_vlans __rcu	*vlan_info;
+#endif
 };
 
 #define br_port_exists(dev) (dev->priv_flags & IFF_BRIDGE_PORT)
@@ -257,6 +272,10 @@
 	struct timer_list		topology_change_timer;
 	struct timer_list		gc_timer;
 	struct kobject			*ifobj;
+#ifdef CONFIG_BRIDGE_VLAN_FILTERING
+	u8				vlan_enabled;
+	struct net_port_vlans __rcu	*vlan_info;
+#endif
 };
 
 struct br_input_skb_cb {
@@ -531,6 +550,46 @@
 }
 #endif
 
+/* br_vlan.c */
+#ifdef CONFIG_BRIDGE_VLAN_FILTERING
+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);
+extern int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val);
+extern int nbp_vlan_add(struct net_bridge_port *port, u16 vid);
+extern int nbp_vlan_delete(struct net_bridge_port *port, u16 vid);
+extern void nbp_vlan_flush(struct net_bridge_port *port);
+#else
+static inline int br_vlan_add(struct net_bridge *br, u16 vid)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int br_vlan_delete(struct net_bridge *br, u16 vid)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void br_vlan_flush(struct net_bridge *br)
+{
+}
+
+static inline int nbp_vlan_add(struct net_bridge_port *port, u16 vid)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void nbp_vlan_flush(struct net_bridge_port *port)
+{
+}
+
+#endif
+
 /* br_netfilter.c */
 #ifdef CONFIG_BRIDGE_NETFILTER
 extern int br_netfilter_init(void);