#ifndef _NDISC_H
  #define _NDISC_H
  
  /*
   *	ICMP codes for neighbour discovery messages
   */
  
  #define NDISC_ROUTER_SOLICITATION	133
  #define NDISC_ROUTER_ADVERTISEMENT	134
  #define NDISC_NEIGHBOUR_SOLICITATION	135
  #define NDISC_NEIGHBOUR_ADVERTISEMENT	136
  #define NDISC_REDIRECT			137
  
  /*
   * Router type: cross-layer information from link-layer to
   * IPv6 layer reported by certain link types (e.g., RFC4214).
   */
  #define NDISC_NODETYPE_UNSPEC		0	/* unspecified (default) */
  #define NDISC_NODETYPE_HOST		1	/* host or unauthorized router */
  #define NDISC_NODETYPE_NODEFAULT	2	/* non-default router */
  #define NDISC_NODETYPE_DEFAULT		3	/* default router */
  
  /*
   *	ndisc options
   */
  
  enum {
  	__ND_OPT_PREFIX_INFO_END = 0,
  	ND_OPT_SOURCE_LL_ADDR = 1,	/* RFC2461 */
  	ND_OPT_TARGET_LL_ADDR = 2,	/* RFC2461 */
  	ND_OPT_PREFIX_INFO = 3,		/* RFC2461 */
  	ND_OPT_REDIRECT_HDR = 4,	/* RFC2461 */
  	ND_OPT_MTU = 5,			/* RFC2461 */
  	__ND_OPT_ARRAY_MAX,
  	ND_OPT_ROUTE_INFO = 24,		/* RFC4191 */
  	ND_OPT_RDNSS = 25,		/* RFC5006 */
  	ND_OPT_DNSSL = 31,		/* RFC6106 */
  	__ND_OPT_MAX
  };
  
  #define MAX_RTR_SOLICITATION_DELAY	HZ
  
  #define ND_REACHABLE_TIME		(30*HZ)
  #define ND_RETRANS_TIMER		HZ
  
  #include <linux/compiler.h>
  #include <linux/icmpv6.h>
  #include <linux/in6.h>
  #include <linux/types.h>
  #include <linux/if_arp.h>
  #include <linux/netdevice.h>
  #include <linux/hash.h>
  
  #include <net/neighbour.h>
  
  struct ctl_table;
  struct inet6_dev;
  struct net_device;
  struct net_proto_family;
  struct sk_buff;
  
  extern struct neigh_table nd_tbl;
  
  struct nd_msg {
          struct icmp6hdr	icmph;
          struct in6_addr	target;
  	__u8		opt[0];
  };
  
  struct rs_msg {
  	struct icmp6hdr	icmph;
  	__u8		opt[0];
  };
  
  struct ra_msg {
          struct icmp6hdr		icmph;
  	__be32			reachable_time;
  	__be32			retrans_timer;
  };
  
  struct rd_msg {
  	struct icmp6hdr icmph;
  	struct in6_addr	target;
  	struct in6_addr	dest;
  	__u8		opt[0];
  };
  
  struct nd_opt_hdr {
  	__u8		nd_opt_type;
  	__u8		nd_opt_len;
  } __packed;
  
  /* ND options */
  struct ndisc_options {
  	struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
  #ifdef CONFIG_IPV6_ROUTE_INFO
  	struct nd_opt_hdr *nd_opts_ri;
  	struct nd_opt_hdr *nd_opts_ri_end;
  #endif
  	struct nd_opt_hdr *nd_useropts;
  	struct nd_opt_hdr *nd_useropts_end;
  };
  
  #define nd_opts_src_lladdr	nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
  #define nd_opts_tgt_lladdr	nd_opt_array[ND_OPT_TARGET_LL_ADDR]
  #define nd_opts_pi		nd_opt_array[ND_OPT_PREFIX_INFO]
  #define nd_opts_pi_end		nd_opt_array[__ND_OPT_PREFIX_INFO_END]
  #define nd_opts_rh		nd_opt_array[ND_OPT_REDIRECT_HDR]
  #define nd_opts_mtu		nd_opt_array[ND_OPT_MTU]
  
  #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
  
  struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len,
  					  struct ndisc_options *ndopts);
  
  /*
   * Return the padding between the option length and the start of the
   * link addr.  Currently only IP-over-InfiniBand needs this, although
   * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
   * also need a pad of 2.
   */
  static inline int ndisc_addr_option_pad(unsigned short type)
  {
  	switch (type) {
  	case ARPHRD_INFINIBAND: return 2;
  	default:                return 0;
  	}
  }
  
  static inline int ndisc_opt_addr_space(struct net_device *dev)
  {
  	return NDISC_OPT_SPACE(dev->addr_len +
  			       ndisc_addr_option_pad(dev->type));
  }
  
  static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
  				      struct net_device *dev)
  {
  	u8 *lladdr = (u8 *)(p + 1);
  	int lladdrlen = p->nd_opt_len << 3;
  	int prepad = ndisc_addr_option_pad(dev->type);
  	if (lladdrlen != ndisc_opt_addr_space(dev))
  		return NULL;
  	return lladdr + prepad;
  }
  
  static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd)
  {
  	const u32 *p32 = pkey;
  
  	return (((p32[0] ^ hash32_ptr(dev)) * hash_rnd[0]) +
  		(p32[1] * hash_rnd[1]) +
  		(p32[2] * hash_rnd[2]) +
  		(p32[3] * hash_rnd[3]));
  }
  
  static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey)
  {
  	struct neigh_hash_table *nht;
  	const u32 *p32 = pkey;
  	struct neighbour *n;
  	u32 hash_val;
  
  	nht = rcu_dereference_bh(nd_tbl.nht);
  	hash_val = ndisc_hashfn(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
  	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
  	     n != NULL;
  	     n = rcu_dereference_bh(n->next)) {
  		u32 *n32 = (u32 *) n->primary_key;
  		if (n->dev == dev &&
  		    ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |
  		     (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0)
  			return n;
  	}
  
  	return NULL;
  }
  
  static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)
  {
  	struct neighbour *n;
  
  	rcu_read_lock_bh();
  	n = __ipv6_neigh_lookup_noref(dev, pkey);
  	if (n && !atomic_inc_not_zero(&n->refcnt))
  		n = NULL;
  	rcu_read_unlock_bh();
  
  	return n;
  }
  
  int ndisc_init(void);
  int ndisc_late_init(void);
  
  void ndisc_late_cleanup(void);
  void ndisc_cleanup(void);
  
  int ndisc_rcv(struct sk_buff *skb);
  
  void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
  		   const struct in6_addr *solicit,
  		   const struct in6_addr *daddr, const struct in6_addr *saddr);
  
  void ndisc_send_rs(struct net_device *dev,
  		   const struct in6_addr *saddr, const struct in6_addr *daddr);
  void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
  		   const struct in6_addr *daddr,
  		   const struct in6_addr *solicited_addr,
  		   bool router, bool solicited, bool override, bool inc_opt);
  
  void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
  
  int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
  		 int dir);
  
  
  /*
   *	IGMP
   */
  int igmp6_init(void);
  
  void igmp6_cleanup(void);
  
  int igmp6_event_query(struct sk_buff *skb);
  
  int igmp6_event_report(struct sk_buff *skb);
  
  
  #ifdef CONFIG_SYSCTL
  int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write,
  			       void __user *buffer, size_t *lenp, loff_t *ppos);
  int ndisc_ifinfo_sysctl_strategy(struct ctl_table *ctl,
  				 void __user *oldval, size_t __user *oldlenp,
  				 void __user *newval, size_t newlen);
  #endif
  
  void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
  
  #endif