extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
extern u16 vlan_dev_vlan_id(const struct net_device *dev);
extern bool vlan_do_receive(struct sk_buff **skb);
extern struct sk_buff *vlan_untag(struct sk_buff *skb);
extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
extern u16 vlan_dev_vlan_id(const struct net_device *dev);
extern bool vlan_do_receive(struct sk_buff **skb);
extern struct sk_buff *vlan_untag(struct sk_buff *skb);