/*
   * 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_
  
  #ifdef __KERNEL__
  
  /* externally defined structs */
  struct vlan_group;
  struct net_device;
  struct packet_type;
  struct vlan_collection;
  struct vlan_dev_info;
  struct hlist_node;

  #include <linux/netdevice.h>

  #include <linux/etherdevice.h>

  
  #define VLAN_HLEN	4		/* The additional bytes (on top of the Ethernet header)
  					 * that VLAN requires.
  					 */
  #define VLAN_ETH_ALEN	6		/* Octets in one ethernet addr	 */
  #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_ethhdr {
     unsigned char	h_dest[ETH_ALEN];	   /* destination eth addr	*/
     unsigned char	h_source[ETH_ALEN];	   /* source ether addr	*/

     __be16               h_vlan_proto;              /* Should always be 0x8100 */
     __be16               h_vlan_TCI;                /* Encapsulates priority and VLAN ID */

     __be16		h_vlan_encapsulated_proto; /* packet type ID field (or len) */

  };
  
  #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);

  }
  
  struct vlan_hdr {

     __be16               h_vlan_TCI;                /* Encapsulates priority and VLAN ID */
     __be16               h_vlan_encapsulated_proto; /* packet type ID field (or len) */

  };
  
  #define VLAN_VID_MASK	0xfff
  
  /* found in socket.c */
  extern void vlan_ioctl_set(int (*hook)(void __user *));
  
  #define VLAN_NAME "vlan"
  
  /* if this changes, algorithm will have to be reworked because this
   * depends on completely exhausting the VLAN identifier space.  Thus
   * it gives constant time look-up, but in many cases it wastes memory.
   */

  #define VLAN_GROUP_ARRAY_LEN          4096
  #define VLAN_GROUP_ARRAY_SPLIT_PARTS  8
  #define VLAN_GROUP_ARRAY_PART_LEN     (VLAN_GROUP_ARRAY_LEN/VLAN_GROUP_ARRAY_SPLIT_PARTS)

  
  struct vlan_group {
  	int real_dev_ifindex; /* The ifindex of the ethernet(like) device the vlan is attached to. */
  	struct hlist_node	hlist;	/* linked list */

  	struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];

  	struct rcu_head		rcu;
  };

  static inline struct net_device *vlan_group_get_device(struct vlan_group *vg, int vlan_id)
  {
  	struct net_device **array;
  	array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
  	return array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN];
  }
  
  static inline void vlan_group_set_device(struct vlan_group *vg, int vlan_id,
  					 struct net_device *dev)
  {
  	struct net_device **array;
  	if (!vg)
  		return;
  	array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
  	array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
  }

  struct vlan_priority_tci_mapping {
  	unsigned long priority;
  	unsigned short vlan_qos; /* This should be shifted when first set, so we only do it
  				  * at provisioning time.
  				  * ((skb->priority << 13) & 0xE000)
  				  */
  	struct vlan_priority_tci_mapping *next;
  };
  
  /* Holds information that makes sense if this device is a VLAN device. */
  struct vlan_dev_info {
  	/** This will be the mapping that correlates skb->priority to
  	 * 3 bits of VLAN QOS tags...
  	 */
  	unsigned long ingress_priority_map[8];
  	struct vlan_priority_tci_mapping *egress_priority_map[16]; /* hash table */
  
  	unsigned short vlan_id;        /*  The VLAN Identifier for this interface. */
  	unsigned short flags;          /* (1 << 0) re_order_header   This option will cause the
                                          *   VLAN code to move around the ethernet header on
                                          *   ingress to make the skb look **exactly** like it
                                          *   came in from an ethernet port.  This destroys some of
                                          *   the VLAN information in the skb, but it fixes programs
                                          *   like DHCP that use packet-filtering and don't understand
                                          *   802.1Q
                                          */
  	struct dev_mc_list *old_mc_list;  /* old multi-cast list for the VLAN interface..
                                             * we save this so we can tell what changes were
                                             * made, in order to feed the right changes down
                                             * to the real hardware...
                                             */
  	int old_allmulti;               /* similar to above. */
  	int old_promiscuity;            /* similar to above. */
  	struct net_device *real_dev;    /* the underlying device/interface */
  	struct proc_dir_entry *dent;    /* Holds the proc data */
  	unsigned long cnt_inc_headroom_on_tx; /* How many times did we have to grow the skb on TX. */
  	unsigned long cnt_encap_on_xmit;      /* How many times did we have to encapsulate the skb on TX. */
  	struct net_device_stats dev_stats; /* Device stats (rx-bytes, tx-pkts, etc...) */
  };
  
  #define VLAN_DEV_INFO(x) ((struct vlan_dev_info *)(x->priv))
  
  /* inline functions */
  
  static inline struct net_device_stats *vlan_dev_get_stats(struct net_device *dev)
  {
  	return &(VLAN_DEV_INFO(dev)->dev_stats);
  }
  
  static inline __u32 vlan_get_ingress_priority(struct net_device *dev,
  					      unsigned short vlan_tag)
  {
  	struct vlan_dev_info *vip = VLAN_DEV_INFO(dev);
  
  	return vip->ingress_priority_map[(vlan_tag >> 13) & 0x7];
  }
  
  /* VLAN tx hw acceleration helpers. */
  struct vlan_skb_tx_cookie {
  	u32	magic;
  	u32	vlan_tag;
  };
  
  #define VLAN_TX_COOKIE_MAGIC	0x564c414e	/* "VLAN" in ascii. */
  #define VLAN_TX_SKB_CB(__skb)	((struct vlan_skb_tx_cookie *)&((__skb)->cb[0]))
  #define vlan_tx_tag_present(__skb) \
  	(VLAN_TX_SKB_CB(__skb)->magic == VLAN_TX_COOKIE_MAGIC)
  #define vlan_tx_tag_get(__skb)	(VLAN_TX_SKB_CB(__skb)->vlan_tag)
  
  /* VLAN rx hw acceleration helper.  This acts like netif_{rx,receive_skb}(). */
  static inline int __vlan_hwaccel_rx(struct sk_buff *skb,
  				    struct vlan_group *grp,
  				    unsigned short vlan_tag, int polling)
  {
  	struct net_device_stats *stats;

  	if (skb_bond_should_drop(skb)) {
  		dev_kfree_skb_any(skb);
  		return NET_RX_DROP;
  	}

  	skb->dev = vlan_group_get_device(grp, vlan_tag & VLAN_VID_MASK);

  	if (skb->dev == NULL) {
  		dev_kfree_skb_any(skb);
  
  		/* Not NET_RX_DROP, this is not being dropped
  		 * due to congestion.
  		 */
  		return 0;
  	}
  
  	skb->dev->last_rx = jiffies;
  
  	stats = vlan_dev_get_stats(skb->dev);
  	stats->rx_packets++;
  	stats->rx_bytes += skb->len;
  
  	skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tag);
  	switch (skb->pkt_type) {
  	case PACKET_BROADCAST:
  		break;
  
  	case PACKET_MULTICAST:
  		stats->multicast++;
  		break;
  
  	case PACKET_OTHERHOST:
  		/* Our lower layer thinks this is not local, let's make sure.
  		 * This allows the VLAN to have a different MAC than the underlying
  		 * device, and still route correctly.
  		 */

  		if (!compare_ether_addr(eth_hdr(skb)->h_dest,
  				       	skb->dev->dev_addr))

  			skb->pkt_type = PACKET_HOST;
  		break;
  	};
  
  	return (polling ? netif_receive_skb(skb) : netif_rx(skb));
  }
  
  static inline int vlan_hwaccel_rx(struct sk_buff *skb,
  				  struct vlan_group *grp,
  				  unsigned short vlan_tag)
  {
  	return __vlan_hwaccel_rx(skb, grp, vlan_tag, 0);
  }
  
  static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
  					   struct vlan_group *grp,
  					   unsigned short vlan_tag)
  {
  	return __vlan_hwaccel_rx(skb, grp, vlan_tag, 1);
  }
  
  /**
   * __vlan_put_tag - regular VLAN tag inserting
   * @skb: skbuff to tag
   * @tag: VLAN tag 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, unsigned short tag)
  {
  	struct vlan_ethhdr *veth;
  
  	if (skb_headroom(skb) < VLAN_HLEN) {
  		struct sk_buff *sk_tmp = skb;
  		skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN);
  		kfree_skb(sk_tmp);
  		if (!skb) {
  			printk(KERN_ERR "vlan: failed to realloc headroom
  ");
  			return NULL;
  		}
  	} else {
  		skb = skb_unshare(skb, GFP_ATOMIC);
  		if (!skb) {
  			printk(KERN_ERR "vlan: failed to unshare skbuff
  ");
  			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 * VLAN_ETH_ALEN);
  
  	/* first, the ethernet type */
  	veth->h_vlan_proto = __constant_htons(ETH_P_8021Q);
  
  	/* now, the tag */
  	veth->h_vlan_TCI = htons(tag);
  
  	skb->protocol = __constant_htons(ETH_P_8021Q);

  	skb->mac_header -= VLAN_HLEN;
  	skb->network_header -= VLAN_HLEN;

  
  	return skb;
  }
  
  /**
   * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
   * @skb: skbuff to tag
   * @tag: VLAN tag to insert
   *
   * Puts the VLAN tag in @skb->cb[] and lets the device do the rest
   */
  static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, unsigned short tag)
  {
  	struct vlan_skb_tx_cookie *cookie;
  
  	cookie = VLAN_TX_SKB_CB(skb);
  	cookie->magic = VLAN_TX_COOKIE_MAGIC;
  	cookie->vlan_tag = tag;
  
  	return skb;
  }
  
  #define HAVE_VLAN_PUT_TAG
  
  /**
   * vlan_put_tag - inserts VLAN tag according to device features
   * @skb: skbuff to tag
   * @tag: VLAN tag 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, unsigned short tag)
  {
  	if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
  		return __vlan_hwaccel_put_tag(skb, tag);
  	} else {
  		return __vlan_put_tag(skb, tag);
  	}
  }
  
  /**
   * __vlan_get_tag - get the VLAN ID that is part of the payload
   * @skb: skbuff to query
   * @tag: buffer to store vlaue
   * 
   * Returns error if the skb is not of VLAN type
   */
  static inline int __vlan_get_tag(struct sk_buff *skb, unsigned short *tag)
  {
  	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
  
  	if (veth->h_vlan_proto != __constant_htons(ETH_P_8021Q)) {
  		return -EINVAL;
  	}
  
  	*tag = ntohs(veth->h_vlan_TCI);
  
  	return 0;
  }
  
  /**
   * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
   * @skb: skbuff to query
   * @tag: buffer to store vlaue
   * 
   * Returns error if @skb->cb[] is not set correctly
   */
  static inline int __vlan_hwaccel_get_tag(struct sk_buff *skb, unsigned short *tag)
  {
  	struct vlan_skb_tx_cookie *cookie;
  
  	cookie = VLAN_TX_SKB_CB(skb);
  	if (cookie->magic == VLAN_TX_COOKIE_MAGIC) {
  		*tag = cookie->vlan_tag;
  		return 0;
  	} else {
  		*tag = 0;
  		return -EINVAL;
  	}
  }
  
  #define HAVE_VLAN_GET_TAG
  
  /**
   * vlan_get_tag - get the VLAN ID from the skb
   * @skb: skbuff to query
   * @tag: buffer to store vlaue
   * 
   * Returns error if the skb is not VLAN tagged
   */
  static inline int vlan_get_tag(struct sk_buff *skb, unsigned short *tag)
  {
  	if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
  		return __vlan_hwaccel_get_tag(skb, tag);
  	} else {
  		return __vlan_get_tag(skb, tag);
  	}
  }
  
  #endif /* __KERNEL__ */
  
  /* VLAN IOCTLs are found in sockios.h */
  
  /* Passed in vlan_ioctl_args structure to determine behaviour. */
  enum vlan_ioctl_cmds {
  	ADD_VLAN_CMD,
  	DEL_VLAN_CMD,
  	SET_VLAN_INGRESS_PRIORITY_CMD,
  	SET_VLAN_EGRESS_PRIORITY_CMD,
  	GET_VLAN_INGRESS_PRIORITY_CMD,
  	GET_VLAN_EGRESS_PRIORITY_CMD,
  	SET_VLAN_NAME_TYPE_CMD,
  	SET_VLAN_FLAG_CMD,
  	GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
  	GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
  };
  
  enum vlan_name_types {
  	VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
  	VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
  	VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
  	VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
  	VLAN_NAME_TYPE_HIGHEST
  };
  
  struct vlan_ioctl_args {
  	int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
  	char device1[24];
  
          union {
  		char device2[24];
  		int VID;
  		unsigned int skb_priority;
  		unsigned int name_type;
  		unsigned int bind_type;
  		unsigned int flag; /* Matches vlan_dev_info flags */
          } u;
  
  	short vlan_qos;   
  };
  
  #endif /* !(_LINUX_IF_VLAN_H_) */