#ifndef _NET_NEIGHBOUR_H
  #define _NET_NEIGHBOUR_H

  #include <linux/neighbour.h>

  /*
   *	Generic neighbour manipulation
   *
   *	Authors:
   *	Pedro Roque		<roque@di.fc.ul.pt>
   *	Alexey Kuznetsov	<kuznet@ms2.inr.ac.ru>
   *
   * 	Changes:
   *
   *	Harald Welte:		<laforge@gnumonks.org>
   *		- Add neighbour cache statistics like rtstat
   */

  #include <linux/atomic.h>

  #include <linux/netdevice.h>

  #include <linux/skbuff.h>

  #include <linux/rcupdate.h>
  #include <linux/seq_file.h>
  
  #include <linux/err.h>
  #include <linux/sysctl.h>

  #include <linux/workqueue.h>

  #include <net/rtnetlink.h>

  /*
   * NUD stands for "neighbor unreachability detection"
   */

  #define NUD_IN_TIMER	(NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE)
  #define NUD_VALID	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
  #define NUD_CONNECTED	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE)
  
  struct neighbour;

  struct neigh_parms {

  #ifdef CONFIG_NET_NS

  	struct net *net;

  #endif

  	struct net_device *dev;

  	struct neigh_parms *next;
  	int	(*neigh_setup)(struct neighbour *);

  	void	(*neigh_cleanup)(struct neighbour *);

  	struct neigh_table *tbl;

  
  	void	*sysctl_table;
  
  	int dead;
  	atomic_t refcnt;
  	struct rcu_head rcu_head;
  
  	int	base_reachable_time;
  	int	retrans_time;
  	int	gc_staletime;
  	int	reachable_time;
  	int	delay_probe_time;
  
  	int	queue_len;
  	int	ucast_probes;
  	int	app_probes;
  	int	mcast_probes;
  	int	anycast_delay;
  	int	proxy_delay;
  	int	proxy_qlen;
  	int	locktime;
  };

  struct neigh_statistics {

  	unsigned long allocs;		/* number of allocated neighs */
  	unsigned long destroys;		/* number of destroyed neighs */
  	unsigned long hash_grows;	/* number of hash resizes */

  	unsigned long res_failed;	/* number of failed resolutions */

  
  	unsigned long lookups;		/* number of lookups */
  	unsigned long hits;		/* number of hits (among lookups) */
  
  	unsigned long rcv_probes_mcast;	/* number of received mcast ipv6 */
  	unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */
  
  	unsigned long periodic_gc_runs;	/* number of periodic GC runs */
  	unsigned long forced_gc_runs;	/* number of forced GC runs */

  
  	unsigned long unres_discards;	/* number of unresolved drops */

  };

  #define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field)

  struct neighbour {

  	struct neighbour __rcu	*next;

  	struct neigh_table	*tbl;
  	struct neigh_parms	*parms;

  	unsigned long		confirmed;
  	unsigned long		updated;

  	rwlock_t		lock;

  	atomic_t		refcnt;

  	struct sk_buff_head	arp_queue;
  	struct timer_list	timer;
  	unsigned long		used;

  	atomic_t		probes;

  	__u8			flags;
  	__u8			nud_state;
  	__u8			type;
  	__u8			dead;

  	seqlock_t		ha_lock;

  	unsigned char		ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))];

  	struct hh_cache		hh;

  	int			(*output)(struct neighbour *, struct sk_buff *);

  	const struct neigh_ops	*ops;

  	struct rcu_head		rcu;

  	struct net_device	*dev;

  	u8			primary_key[0];
  };

  struct neigh_ops {

  	int			family;

  	void			(*solicit)(struct neighbour *, struct sk_buff *);
  	void			(*error_report)(struct neighbour *, struct sk_buff *);
  	int			(*output)(struct neighbour *, struct sk_buff *);
  	int			(*connected_output)(struct neighbour *, struct sk_buff *);

  };

  struct pneigh_entry {

  	struct pneigh_entry	*next;

  #ifdef CONFIG_NET_NS

  	struct net		*net;

  #endif

  	struct net_device	*dev;

  	u8			flags;

  	u8			key[0];
  };
  
  /*
   *	neighbour table manipulation
   */

  struct neigh_hash_table {

  	struct neighbour __rcu	**hash_buckets;

  	unsigned int		hash_shift;

  	__u32			hash_rnd;
  	struct rcu_head		rcu;
  };

  struct neigh_table {

  	struct neigh_table	*next;
  	int			family;
  	int			entry_size;
  	int			key_len;

  	__u32			(*hash)(const void *pkey,
  					const struct net_device *dev,
  					__u32 hash_rnd);

  	int			(*constructor)(struct neighbour *);
  	int			(*pconstructor)(struct pneigh_entry *);
  	void			(*pdestructor)(struct pneigh_entry *);
  	void			(*proxy_redo)(struct sk_buff *skb);
  	char			*id;
  	struct neigh_parms	parms;

  	/* HACK. gc_* should follow parms without a gap! */

  	int			gc_interval;
  	int			gc_thresh1;
  	int			gc_thresh2;
  	int			gc_thresh3;
  	unsigned long		last_flush;

  	struct delayed_work	gc_work;

  	struct timer_list 	proxy_timer;
  	struct sk_buff_head	proxy_queue;
  	atomic_t		entries;
  	rwlock_t		lock;
  	unsigned long		last_rand;

  	struct kmem_cache	*kmem_cachep;

  	struct neigh_statistics	__percpu *stats;

  	struct neigh_hash_table __rcu *nht;

  	struct pneigh_entry	**phash_buckets;

  };
  
  /* flags for neigh_update() */
  #define NEIGH_UPDATE_F_OVERRIDE			0x00000001
  #define NEIGH_UPDATE_F_WEAK_OVERRIDE		0x00000002
  #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER	0x00000004
  #define NEIGH_UPDATE_F_ISROUTER			0x40000000
  #define NEIGH_UPDATE_F_ADMIN			0x80000000
  
  extern void			neigh_table_init(struct neigh_table *tbl);

  extern void			neigh_table_init_no_netlink(struct neigh_table *tbl);

  extern int			neigh_table_clear(struct neigh_table *tbl);
  extern struct neighbour *	neigh_lookup(struct neigh_table *tbl,
  					     const void *pkey,
  					     struct net_device *dev);
  extern struct neighbour *	neigh_lookup_nodev(struct neigh_table *tbl,

  						   struct net *net,

  						   const void *pkey);
  extern struct neighbour *	neigh_create(struct neigh_table *tbl,
  					     const void *pkey,
  					     struct net_device *dev);
  extern void			neigh_destroy(struct neighbour *neigh);
  extern int			__neigh_event_send(struct neighbour *neigh, struct sk_buff *skb);
  extern int			neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, 
  					     u32 flags);
  extern void			neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev);
  extern int			neigh_ifdown(struct neigh_table *tbl, struct net_device *dev);

  extern int			neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb);
  extern int			neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb);
  extern int			neigh_compat_output(struct neighbour *neigh, struct sk_buff *skb);
  extern int			neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb);

  extern struct neighbour 	*neigh_event_ns(struct neigh_table *tbl,
  						u8 *lladdr, void *saddr,
  						struct net_device *dev);
  
  extern struct neigh_parms	*neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl);
  extern void			neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms);

  
  static inline
  struct net			*neigh_parms_net(const struct neigh_parms *parms)
  {

  	return read_pnet(&parms->net);

  }

  extern unsigned long		neigh_rand_reach_time(unsigned long base);
  
  extern void			pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
  					       struct sk_buff *skb);

  extern struct pneigh_entry	*pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat);

  extern struct pneigh_entry	*__pneigh_lookup(struct neigh_table *tbl,
  						 struct net *net,
  						 const void *key,
  						 struct net_device *dev);

  extern int			pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev);

  static inline
  struct net			*pneigh_net(const struct pneigh_entry *pneigh)
  {

  	return read_pnet(&pneigh->net);

  }

  extern void neigh_app_ns(struct neighbour *n);

  extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie);
  extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *));
  extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *));
  
  struct neigh_seq_state {

  	struct seq_net_private p;

  	struct neigh_table *tbl;

  	struct neigh_hash_table *nht;

  	void *(*neigh_sub_iter)(struct neigh_seq_state *state,
  				struct neighbour *n, loff_t *pos);
  	unsigned int bucket;
  	unsigned int flags;
  #define NEIGH_SEQ_NEIGH_ONLY	0x00000001
  #define NEIGH_SEQ_IS_PNEIGH	0x00000002
  #define NEIGH_SEQ_SKIP_NOARP	0x00000004
  };
  extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int);
  extern void *neigh_seq_next(struct seq_file *, void *, loff_t *);
  extern void neigh_seq_stop(struct seq_file *, void *);
  
  extern int			neigh_sysctl_register(struct net_device *dev, 
  						      struct neigh_parms *p,

  						      char *p_name,

  						      proc_handler *proc_handler);

  extern void			neigh_sysctl_unregister(struct neigh_parms *p);
  
  static inline void __neigh_parms_put(struct neigh_parms *parms)
  {
  	atomic_dec(&parms->refcnt);
  }

  static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms)
  {
  	atomic_inc(&parms->refcnt);
  	return parms;
  }
  
  /*
   *	Neighbour references
   */
  
  static inline void neigh_release(struct neighbour *neigh)
  {
  	if (atomic_dec_and_test(&neigh->refcnt))
  		neigh_destroy(neigh);
  }
  
  static inline struct neighbour * neigh_clone(struct neighbour *neigh)
  {
  	if (neigh)
  		atomic_inc(&neigh->refcnt);
  	return neigh;
  }
  
  #define neigh_hold(n)	atomic_inc(&(n)->refcnt)
  
  static inline void neigh_confirm(struct neighbour *neigh)
  {
  	if (neigh)
  		neigh->confirmed = jiffies;
  }

  static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb)
  {

  	unsigned long now = jiffies;

  	
  	if (neigh->used != now)
  		neigh->used = now;

  	if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE)))
  		return __neigh_event_send(neigh, skb);
  	return 0;
  }

  #ifdef CONFIG_BRIDGE_NETFILTER
  static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb)
  {
  	unsigned seq, hh_alen;
  
  	do {
  		seq = read_seqbegin(&hh->hh_lock);
  		hh_alen = HH_DATA_ALIGN(ETH_HLEN);
  		memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN);
  	} while (read_seqretry(&hh->hh_lock, seq));
  	return 0;
  }
  #endif

  static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb)
  {
  	unsigned seq;
  	int hh_len;
  
  	do {
  		int hh_alen;
  
  		seq = read_seqbegin(&hh->hh_lock);
  		hh_len = hh->hh_len;
  		hh_alen = HH_DATA_ALIGN(hh_len);
  		memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
  	} while (read_seqretry(&hh->hh_lock, seq));
  
  	skb_push(skb, hh_len);

  	return dev_queue_xmit(skb);

  }

  static inline int neigh_output(struct neighbour *n, struct sk_buff *skb)
  {
  	struct hh_cache *hh = &n->hh;

  	if ((n->nud_state & NUD_CONNECTED) && hh->hh_len)

  		return neigh_hh_output(hh, skb);
  	else

  		return n->output(n, skb);

  }

  static inline struct neighbour *
  __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat)
  {
  	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
  
  	if (n || !creat)
  		return n;
  
  	n = neigh_create(tbl, pkey, dev);
  	return IS_ERR(n) ? NULL : n;
  }
  
  static inline struct neighbour *
  __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey,
    struct net_device *dev)
  {
  	struct neighbour *n = neigh_lookup(tbl, pkey, dev);
  
  	if (n)
  		return n;
  
  	return neigh_create(tbl, pkey, dev);
  }

  struct neighbour_cb {
  	unsigned long sched_next;
  	unsigned int flags;
  };
  
  #define LOCALLY_ENQUEUED 0x1
  
  #define NEIGH_CB(skb)	((struct neighbour_cb *)(skb)->cb)

  static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n,
  				     const struct net_device *dev)
  {
  	unsigned int seq;
  
  	do {
  		seq = read_seqbegin(&n->ha_lock);
  		memcpy(dst, n->ha, dev->addr_len);
  	} while (read_seqretry(&n->ha_lock, seq));
  }

  #endif