batman-adv: make the Distributed ARP Table vlan aware

The same IP subnet can be used on different VLANs, therefore
DAT has to differentiate whether the IP to resolve belongs
to one or the other virtual LAN.
To accomplish this task DAT has to deal with the VLAN tag
and store it together with each ARP entry.
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

net/batman-adv/types.h

@@ -933,6 +933,7 @@ struct batadv_algo_ops {
  * is used to stored ARP entries needed for the global DAT cache
  * @ip: the IPv4 corresponding to this DAT/ARP entry
  * @mac_addr: the MAC address associated to the stored IPv4
+ * @vid: the vlan ID associated to this entry
  * @last_update: time in jiffies when this entry was refreshed last time
  * @hash_entry: hlist node for batadv_priv_dat::hash
  * @refcount: number of contexts the object is used
@@ -941,6 +942,7 @@ struct batadv_algo_ops {
 struct batadv_dat_entry {
 	__be32 ip;
 	uint8_t mac_addr[ETH_ALEN];
+	unsigned short vid;
 	unsigned long last_update;
 	struct hlist_node hash_entry;
 	atomic_t refcount;