/*
   * VLAN		An implementation of 802.1Q VLAN tagging.
   *
   * Authors:	Ben Greear <greearb@candelatech.com>
   *
   *		This program is free software; you can redistribute it and/or
   *		modify it under the terms of the GNU General Public License
   *		as published by the Free Software Foundation; either version
   *		2 of the License, or (at your option) any later version.
   *
   */
  #ifndef _LINUX_IF_VLAN_H_
  #define _LINUX_IF_VLAN_H_
  
  #include <linux/netdevice.h>
  #include <linux/etherdevice.h>
  #include <linux/rtnetlink.h>
  #include <linux/bug.h>
  #include <uapi/linux/if_vlan.h>
  
  #define VLAN_HLEN	4		/* The additional bytes required by VLAN
  					 * (in addition to the Ethernet header)
  					 */
  #define VLAN_ETH_HLEN	18		/* Total octets in header.	 */
  #define VLAN_ETH_ZLEN	64		/* Min. octets in frame sans FCS */
  
  /*
   * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
   */
  #define VLAN_ETH_DATA_LEN	1500	/* Max. octets in payload	 */
  #define VLAN_ETH_FRAME_LEN	1518	/* Max. octets in frame sans FCS */
  
  /*
   * 	struct vlan_hdr - vlan header
   * 	@h_vlan_TCI: priority and VLAN ID
   *	@h_vlan_encapsulated_proto: packet type ID or len
   */
  struct vlan_hdr {
  	__be16	h_vlan_TCI;
  	__be16	h_vlan_encapsulated_proto;
  };
  
  /**
   *	struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
   *	@h_dest: destination ethernet address
   *	@h_source: source ethernet address
   *	@h_vlan_proto: ethernet protocol
   *	@h_vlan_TCI: priority and VLAN ID
   *	@h_vlan_encapsulated_proto: packet type ID or len
   */
  struct vlan_ethhdr {
  	unsigned char	h_dest[ETH_ALEN];
  	unsigned char	h_source[ETH_ALEN];
  	__be16		h_vlan_proto;
  	__be16		h_vlan_TCI;
  	__be16		h_vlan_encapsulated_proto;
  };
  
  #include <linux/skbuff.h>
  
  static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
  {
  	return (struct vlan_ethhdr *)skb_mac_header(skb);
  }
  
  #define VLAN_PRIO_MASK		0xe000 /* Priority Code Point */
  #define VLAN_PRIO_SHIFT		13
  #define VLAN_CFI_MASK		0x1000 /* Canonical Format Indicator */
  #define VLAN_TAG_PRESENT	VLAN_CFI_MASK
  #define VLAN_VID_MASK		0x0fff /* VLAN Identifier */
  #define VLAN_N_VID		4096
  
  /* found in socket.c */
  extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
  
  static inline bool is_vlan_dev(struct net_device *dev)
  {
          return dev->priv_flags & IFF_802_1Q_VLAN;
  }
  
  #define vlan_tx_tag_present(__skb)	((__skb)->vlan_tci & VLAN_TAG_PRESENT)
  #define vlan_tx_tag_get(__skb)		((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
  #define vlan_tx_tag_get_id(__skb)	((__skb)->vlan_tci & VLAN_VID_MASK)
  
  /**
   *	struct vlan_pcpu_stats - VLAN percpu rx/tx stats
   *	@rx_packets: number of received packets
   *	@rx_bytes: number of received bytes
   *	@rx_multicast: number of received multicast packets
   *	@tx_packets: number of transmitted packets
   *	@tx_bytes: number of transmitted bytes
   *	@syncp: synchronization point for 64bit counters
   *	@rx_errors: number of rx errors
   *	@tx_dropped: number of tx drops
   */
  struct vlan_pcpu_stats {
  	u64			rx_packets;
  	u64			rx_bytes;
  	u64			rx_multicast;
  	u64			tx_packets;
  	u64			tx_bytes;
  	struct u64_stats_sync	syncp;
  	u32			rx_errors;
  	u32			tx_dropped;
  };
  
  #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
  
  extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
  					       __be16 vlan_proto, u16 vlan_id);
  extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
  extern u16 vlan_dev_vlan_id(const struct net_device *dev);
  
  /**
   *	struct vlan_priority_tci_mapping - vlan egress priority mappings
   *	@priority: skb priority
   *	@vlan_qos: vlan priority: (skb->priority << 13) & 0xE000
   *	@next: pointer to next struct
   */
  struct vlan_priority_tci_mapping {
  	u32					priority;
  	u16					vlan_qos;
  	struct vlan_priority_tci_mapping	*next;
  };
  
  struct proc_dir_entry;
  struct netpoll;
  
  /**
   *	struct vlan_dev_priv - VLAN private device data
   *	@nr_ingress_mappings: number of ingress priority mappings
   *	@ingress_priority_map: ingress priority mappings
   *	@nr_egress_mappings: number of egress priority mappings
   *	@egress_priority_map: hash of egress priority mappings
   *	@vlan_proto: VLAN encapsulation protocol
   *	@vlan_id: VLAN identifier
   *	@flags: device flags
   *	@real_dev: underlying netdevice
   *	@real_dev_addr: address of underlying netdevice
   *	@dent: proc dir entry
   *	@vlan_pcpu_stats: ptr to percpu rx stats
   */
  struct vlan_dev_priv {
  	unsigned int				nr_ingress_mappings;
  	u32					ingress_priority_map[8];
  	unsigned int				nr_egress_mappings;
  	struct vlan_priority_tci_mapping	*egress_priority_map[16];
  
  	__be16					vlan_proto;
  	u16					vlan_id;
  	u16					flags;
  
  	struct net_device			*real_dev;
  	unsigned char				real_dev_addr[ETH_ALEN];
  
  	struct proc_dir_entry			*dent;
  	struct vlan_pcpu_stats __percpu		*vlan_pcpu_stats;
  #ifdef CONFIG_NET_POLL_CONTROLLER
  	struct netpoll				*netpoll;
  #endif
  	unsigned int				nest_level;
  };
  
  static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev)
  {
  	return netdev_priv(dev);
  }
  
  static inline u16
  vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio)
  {
  	struct vlan_priority_tci_mapping *mp;
  
  	smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */
  
  	mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)];
  	while (mp) {
  		if (mp->priority == skprio) {
  			return mp->vlan_qos; /* This should already be shifted
  					      * to mask correctly with the
  					      * VLAN's TCI */
  		}
  		mp = mp->next;
  	}
  	return 0;
  }
  
  extern bool vlan_do_receive(struct sk_buff **skb);
  
  extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid);
  extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid);
  
  extern int vlan_vids_add_by_dev(struct net_device *dev,
  				const struct net_device *by_dev);
  extern void vlan_vids_del_by_dev(struct net_device *dev,
  				 const struct net_device *by_dev);
  
  extern bool vlan_uses_dev(const struct net_device *dev);
  #else
  static inline struct net_device *
  __vlan_find_dev_deep(struct net_device *real_dev,
  		     __be16 vlan_proto, u16 vlan_id)
  {
  	return NULL;
  }
  
  static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
  {
  	BUG();
  	return NULL;
  }
  
  static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
  {
  	BUG();
  	return 0;
  }
  
  static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev,
  					       u32 skprio)
  {
  	return 0;
  }
  
  static inline bool vlan_do_receive(struct sk_buff **skb)
  {
  	return false;
  }
  
  static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
  {
  	return 0;
  }
  
  static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
  {
  }
  
  static inline int vlan_vids_add_by_dev(struct net_device *dev,
  				       const struct net_device *by_dev)
  {
  	return 0;
  }
  
  static inline void vlan_vids_del_by_dev(struct net_device *dev,
  					const struct net_device *by_dev)
  {
  }
  
  static inline bool vlan_uses_dev(const struct net_device *dev)
  {
  	return false;
  }
  #endif
  
  static inline bool vlan_hw_offload_capable(netdev_features_t features,
  					   __be16 proto)
  {
  	if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX)
  		return true;
  	if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX)
  		return true;
  	return false;
  }
  
  /**
   * vlan_insert_tag - regular VLAN tag inserting
   * @skb: skbuff to tag
   * @vlan_proto: VLAN encapsulation protocol
   * @vlan_tci: VLAN TCI to insert
   *
   * Inserts the VLAN tag into @skb as part of the payload
   * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
   *
   * Following the skb_unshare() example, in case of error, the calling function
   * doesn't have to worry about freeing the original skb.
   *
   * Does not change skb->protocol so this function can be used during receive.
   */
  static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb,
  					      __be16 vlan_proto, u16 vlan_tci)
  {
  	struct vlan_ethhdr *veth;
  
  	if (skb_cow_head(skb, VLAN_HLEN) < 0) {
  		kfree_skb(skb);
  		return NULL;
  	}
  	veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
  
  	/* Move the mac addresses to the beginning of the new header. */
  	memmove(skb->data, skb->data + VLAN_HLEN, 2 * ETH_ALEN);
  	skb->mac_header -= VLAN_HLEN;
  
  	/* first, the ethernet type */
  	veth->h_vlan_proto = vlan_proto;
  
  	/* now, the TCI */
  	veth->h_vlan_TCI = htons(vlan_tci);
  
  	return skb;
  }
  
  /**
   * __vlan_put_tag - regular VLAN tag inserting
   * @skb: skbuff to tag
   * @vlan_tci: VLAN TCI to insert
   *
   * Inserts the VLAN tag into @skb as part of the payload
   * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
   *
   * Following the skb_unshare() example, in case of error, the calling function
   * doesn't have to worry about freeing the original skb.
   */
  static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb,
  					     __be16 vlan_proto, u16 vlan_tci)
  {
  	skb = vlan_insert_tag(skb, vlan_proto, vlan_tci);
  	if (skb)
  		skb->protocol = vlan_proto;
  	return skb;
  }
  
  /**
   * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
   * @skb: skbuff to tag
   * @vlan_proto: VLAN encapsulation protocol
   * @vlan_tci: VLAN TCI to insert
   *
   * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
   */
  static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
  						     __be16 vlan_proto,
  						     u16 vlan_tci)
  {
  	skb->vlan_proto = vlan_proto;
  	skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
  	return skb;
  }
  
  /**
   * vlan_put_tag - inserts VLAN tag according to device features
   * @skb: skbuff to tag
   * @vlan_tci: VLAN TCI to insert
   *
   * Assumes skb->dev is the target that will xmit this frame.
   * Returns a VLAN tagged skb.
   */
  static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb,
  					   __be16 vlan_proto, u16 vlan_tci)
  {
  	if (vlan_hw_offload_capable(skb->dev->features, vlan_proto)) {
  		return __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
  	} else {
  		return __vlan_put_tag(skb, vlan_proto, vlan_tci);
  	}
  }
  
  /**
   * __vlan_get_tag - get the VLAN ID that is part of the payload
   * @skb: skbuff to query
   * @vlan_tci: buffer to store vlaue
   *
   * Returns error if the skb is not of VLAN type
   */
  static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
  {
  	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
  
  	if (veth->h_vlan_proto != htons(ETH_P_8021Q) &&
  	    veth->h_vlan_proto != htons(ETH_P_8021AD))
  		return -EINVAL;
  
  	*vlan_tci = ntohs(veth->h_vlan_TCI);
  	return 0;
  }
  
  /**
   * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
   * @skb: skbuff to query
   * @vlan_tci: buffer to store vlaue
   *
   * Returns error if @skb->vlan_tci is not set correctly
   */
  static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
  					 u16 *vlan_tci)
  {
  	if (vlan_tx_tag_present(skb)) {
  		*vlan_tci = vlan_tx_tag_get(skb);
  		return 0;
  	} else {
  		*vlan_tci = 0;
  		return -EINVAL;
  	}
  }
  
  #define HAVE_VLAN_GET_TAG
  
  /**
   * vlan_get_tag - get the VLAN ID from the skb
   * @skb: skbuff to query
   * @vlan_tci: buffer to store vlaue
   *
   * Returns error if the skb is not VLAN tagged
   */
  static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
  {
  	if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
  		return __vlan_hwaccel_get_tag(skb, vlan_tci);
  	} else {
  		return __vlan_get_tag(skb, vlan_tci);
  	}
  }
  
  /**
   * vlan_get_protocol - get protocol EtherType.
   * @skb: skbuff to query
   *
   * Returns the EtherType of the packet, regardless of whether it is
   * vlan encapsulated (normal or hardware accelerated) or not.
   */
  static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
  {
  	__be16 protocol = 0;
  
  	if (vlan_tx_tag_present(skb) ||
  	     skb->protocol != cpu_to_be16(ETH_P_8021Q))
  		protocol = skb->protocol;
  	else {
  		__be16 proto, *protop;
  		protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
  						h_vlan_encapsulated_proto),
  						sizeof(proto), &proto);
  		if (likely(protop))
  			protocol = *protop;
  	}
  
  	return protocol;
  }
  
  static inline void vlan_set_encap_proto(struct sk_buff *skb,
  					struct vlan_hdr *vhdr)
  {
  	__be16 proto;
  	unsigned short *rawp;
  
  	/*
  	 * Was a VLAN packet, grab the encapsulated protocol, which the layer
  	 * three protocols care about.
  	 */
  
  	proto = vhdr->h_vlan_encapsulated_proto;
  	if (ntohs(proto) >= ETH_P_802_3_MIN) {
  		skb->protocol = proto;
  		return;
  	}
  
  	rawp = (unsigned short *)(vhdr + 1);
  	if (*rawp == 0xFFFF)
  		/*
  		 * This is a magic hack to spot IPX packets. Older Novell
  		 * breaks the protocol design and runs IPX over 802.3 without
  		 * an 802.2 LLC layer. We look for FFFF which isn't a used
  		 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
  		 * but does for the rest.
  		 */
  		skb->protocol = htons(ETH_P_802_3);
  	else
  		/*
  		 * Real 802.2 LLC
  		 */
  		skb->protocol = htons(ETH_P_802_2);
  }
  #endif /* !(_LINUX_IF_VLAN_H_) */