include/net/ndisc.h - kernel/msm-4.19 - Gitiles

 #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_NONCE = 14,              /* RFC7527 */
 	__ND_OPT_ARRAY_MAX,
 	ND_OPT_ROUTE_INFO = 24,		/* RFC4191 */
 	ND_OPT_RDNSS = 25,		/* RFC5006 */
 	ND_OPT_DNSSL = 31,		/* RFC6106 */
 	ND_OPT_6CO = 34,		/* RFC6775 */
 	__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>

 /* Set to 3 to get tracing... */
 #define ND_DEBUG 1

 #define ND_PRINTK(val, level, fmt, ...)				\
 do {								\
 	if (val <= ND_DEBUG)					\
 		net_##level##_ratelimited(fmt, ##__VA_ARGS__);	\
 } while (0)

 struct ctl_table;
 struct inet6_dev;
 struct net_device;
 struct net_proto_family;
 struct sk_buff;
 struct prefix_info;

 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;
 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 	struct nd_opt_hdr *nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR + 1];
 #endif
 };

 #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 nd_opts_nonce			nd_opt_array[ND_OPT_NONCE]
 #define nd_802154_opts_src_lladdr	nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR]
 #define nd_802154_opts_tgt_lladdr	nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR]

 #define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)

 struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
 					  u8 *opt, int opt_len,
 					  struct ndisc_options *ndopts);

 void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
 			      int data_len, int pad);

 #define NDISC_OPS_REDIRECT_DATA_SPACE	2

 /*
  * This structure defines the hooks for IPv6 neighbour discovery.
  * The following hooks can be defined; unless noted otherwise, they are
  * optional and can be filled with a null pointer.
  *
  * int (*is_useropt)(u8 nd_opt_type):
  *     This function is called when IPv6 decide RA userspace options. if
  *     this function returns 1 then the option given by nd_opt_type will
  *     be handled as userspace option additional to the IPv6 options.
  *
  * int (*parse_options)(const struct net_device *dev,
  *			struct nd_opt_hdr *nd_opt,
  *			struct ndisc_options *ndopts):
  *     This function is called while parsing ndisc ops and put each position
  *     as pointer into ndopts. If this function return unequal 0, then this
  *     function took care about the ndisc option, if 0 then the IPv6 ndisc
  *     option parser will take care about that option.
  *
  * void (*update)(const struct net_device *dev, struct neighbour *n,
  *		  u32 flags, u8 icmp6_type,
  *		  const struct ndisc_options *ndopts):
  *     This function is called when IPv6 ndisc updates the neighbour cache
  *     entry. Additional options which can be updated may be previously
  *     parsed by parse_opts callback and accessible over ndopts parameter.
  *
  * int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
  *			 struct neighbour *neigh, u8 *ha_buf,
  *			 u8 **ha):
  *     This function is called when the necessary option space will be
  *     calculated before allocating a skb. The parameters neigh, ha_buf
  *     abd ha are available on NDISC_REDIRECT messages only.
  *
  * void (*fill_addr_option)(const struct net_device *dev,
  *			    struct sk_buff *skb, u8 icmp6_type,
  *			    const u8 *ha):
  *     This function is called when the skb will finally fill the option
  *     fields inside skb. NOTE: this callback should fill the option
  *     fields to the skb which are previously indicated by opt_space
  *     parameter. That means the decision to add such option should
  *     not lost between these two callbacks, e.g. protected by interface
  *     up state.
  *
  * void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
  *			       const struct prefix_info *pinfo,
  *			       struct inet6_dev *in6_dev,
  *			       struct in6_addr *addr,
  *			       int addr_type, u32 addr_flags,
  *			       bool sllao, bool tokenized,
  *			       __u32 valid_lft, u32 prefered_lft,
  *			       bool dev_addr_generated):
  *     This function is called when a RA messages is received with valid
  *     PIO option fields and an IPv6 address will be added to the interface
  *     for autoconfiguration. The parameter dev_addr_generated reports about
  *     if the address was based on dev->dev_addr or not. This can be used
  *     to add a second address if link-layer operates with two link layer
  *     addresses. E.g. 802.15.4 6LoWPAN.
  */
 struct ndisc_ops {
 	int	(*is_useropt)(u8 nd_opt_type);
 	int	(*parse_options)(const struct net_device *dev,
 				 struct nd_opt_hdr *nd_opt,
 				 struct ndisc_options *ndopts);
 	void	(*update)(const struct net_device *dev, struct neighbour *n,
 			  u32 flags, u8 icmp6_type,
 			  const struct ndisc_options *ndopts);
 	int	(*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
 				  struct neighbour *neigh, u8 *ha_buf,
 				  u8 **ha);
 	void	(*fill_addr_option)(const struct net_device *dev,
 				    struct sk_buff *skb, u8 icmp6_type,
 				    const u8 *ha);
 	void	(*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
 				       const struct prefix_info *pinfo,
 				       struct inet6_dev *in6_dev,
 				       struct in6_addr *addr,
 				       int addr_type, u32 addr_flags,
 				       bool sllao, bool tokenized,
 				       __u32 valid_lft, u32 prefered_lft,
 				       bool dev_addr_generated);
 };

 #if IS_ENABLED(CONFIG_IPV6)
 static inline int ndisc_ops_is_useropt(const struct net_device *dev,
 				       u8 nd_opt_type)
 {
 	if (dev->ndisc_ops && dev->ndisc_ops->is_useropt)
 		return dev->ndisc_ops->is_useropt(nd_opt_type);
 	else
 		return 0;
 }

 static inline int ndisc_ops_parse_options(const struct net_device *dev,
 					  struct nd_opt_hdr *nd_opt,
 					  struct ndisc_options *ndopts)
 {
 	if (dev->ndisc_ops && dev->ndisc_ops->parse_options)
 		return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts);
 	else
 		return 0;
 }

 static inline void ndisc_ops_update(const struct net_device *dev,
 					  struct neighbour *n, u32 flags,
 					  u8 icmp6_type,
 					  const struct ndisc_options *ndopts)
 {
 	if (dev->ndisc_ops && dev->ndisc_ops->update)
 		dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts);
 }

 static inline int ndisc_ops_opt_addr_space(const struct net_device *dev,
 					   u8 icmp6_type)
 {
 	if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space &&
 	    icmp6_type != NDISC_REDIRECT)
 		return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL,
 						      NULL, NULL);
 	else
 		return 0;
 }

 static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev,
 						    struct neighbour *neigh,
 						    u8 *ha_buf, u8 **ha)
 {
 	if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space)
 		return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT,
 						      neigh, ha_buf, ha);
 	else
 		return 0;
 }

 static inline void ndisc_ops_fill_addr_option(const struct net_device *dev,
 					      struct sk_buff *skb,
 					      u8 icmp6_type)
 {
 	if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option &&
 	    icmp6_type != NDISC_REDIRECT)
 		dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL);
 }

 static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev,
 						       struct sk_buff *skb,
 						       const u8 *ha)
 {
 	if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option)
 		dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha);
 }

 static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net,
 						 struct net_device *dev,
 						 const struct prefix_info *pinfo,
 						 struct inet6_dev *in6_dev,
 						 struct in6_addr *addr,
 						 int addr_type, u32 addr_flags,
 						 bool sllao, bool tokenized,
 						 __u32 valid_lft,
 						 u32 prefered_lft,
 						 bool dev_addr_generated)
 {
 	if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr)
 		dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
 						    addr, addr_type,
 						    addr_flags, sllao,
 						    tokenized, valid_lft,
 						    prefered_lft,
 						    dev_addr_generated);
 }
 #endif

 /*
  * 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(unsigned char addr_len, int pad)
 {
 	return NDISC_OPT_SPACE(addr_len + pad);
 }

 #if IS_ENABLED(CONFIG_IPV6)
 static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type)
 {
 	return __ndisc_opt_addr_space(dev->addr_len,
 				      ndisc_addr_option_pad(dev->type)) +
 		ndisc_ops_opt_addr_space(dev, icmp6_type);
 }

 static inline int ndisc_redirect_opt_addr_space(struct net_device *dev,
 						struct neighbour *neigh,
 						u8 *ops_data_buf,
 						u8 **ops_data)
 {
 	return __ndisc_opt_addr_space(dev->addr_len,
 				      ndisc_addr_option_pad(dev->type)) +
 		ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf,
 						  ops_data);
 }
 #endif

 static inline u8 *__ndisc_opt_addr_data(struct nd_opt_hdr *p,
 					unsigned char addr_len, int prepad)
 {
 	u8 *lladdr = (u8 *)(p + 1);
 	int lladdrlen = p->nd_opt_len << 3;
 	if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad))
 		return NULL;
 	return lladdr + prepad;
 }

 static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
 				      struct net_device *dev)
 {
 	return __ndisc_opt_addr_data(p, dev->addr_len,
 				     ndisc_addr_option_pad(dev->type));
 }

 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)
 {
 	return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev);
 }

 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;
 }

 static inline void __ipv6_confirm_neigh(struct net_device *dev,
 					const void *pkey)
 {
 	struct neighbour *n;

 	rcu_read_lock_bh();
 	n = __ipv6_neigh_lookup_noref(dev, pkey);
 	if (n) {
 		unsigned long now = jiffies;

 		/* avoid dirtying neighbour */
 		if (n->confirmed != now)
 			n->confirmed = now;
 	}
 	rcu_read_unlock_bh();
 }

 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, const struct in6_addr *solicit,
 		   const struct in6_addr *daddr, const struct in6_addr *saddr,
 		   u64 nonce);

 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, 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);

 void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
 		  const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
 		  struct ndisc_options *ndopts);

 /*
  *	IGMP
  */
 int igmp6_init(void);
 int igmp6_late_init(void);

 void igmp6_cleanup(void);
 void igmp6_late_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
	#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_NONCE = 14, /* RFC7527 */
	__ND_OPT_ARRAY_MAX,
	ND_OPT_ROUTE_INFO = 24, /* RFC4191 */
	ND_OPT_RDNSS = 25, /* RFC5006 */
	ND_OPT_DNSSL = 31, /* RFC6106 */
	ND_OPT_6CO = 34, /* RFC6775 */
	__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>

	/* Set to 3 to get tracing... */
	#define ND_DEBUG 1

	#define ND_PRINTK(val, level, fmt, ...) \
	do { \
	if (val <= ND_DEBUG) \
	net_##level##_ratelimited(fmt, ##__VA_ARGS__); \
	} while (0)

	struct ctl_table;
	struct inet6_dev;
	struct net_device;
	struct net_proto_family;
	struct sk_buff;
	struct prefix_info;

	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;
	#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
	struct nd_opt_hdr *nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR + 1];
	#endif
	};

	#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 nd_opts_nonce nd_opt_array[ND_OPT_NONCE]
	#define nd_802154_opts_src_lladdr nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR]
	#define nd_802154_opts_tgt_lladdr nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR]

	#define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)

	struct ndisc_options ndisc_parse_options(const struct net_device dev,
	u8 *opt, int opt_len,
	struct ndisc_options *ndopts);

	void __ndisc_fill_addr_option(struct sk_buff skb, int type, void data,
	int data_len, int pad);

	#define NDISC_OPS_REDIRECT_DATA_SPACE 2

	/*
	* This structure defines the hooks for IPv6 neighbour discovery.
	* The following hooks can be defined; unless noted otherwise, they are
	* optional and can be filled with a null pointer.
	*
	* int (*is_useropt)(u8 nd_opt_type):
	* This function is called when IPv6 decide RA userspace options. if
	* this function returns 1 then the option given by nd_opt_type will
	* be handled as userspace option additional to the IPv6 options.
	*
	* int (parse_options)(const struct net_device dev,
	* struct nd_opt_hdr *nd_opt,
	* struct ndisc_options *ndopts):
	* This function is called while parsing ndisc ops and put each position
	* as pointer into ndopts. If this function return unequal 0, then this
	* function took care about the ndisc option, if 0 then the IPv6 ndisc
	* option parser will take care about that option.
	*
	* void (update)(const struct net_device dev, struct neighbour *n,
	* u32 flags, u8 icmp6_type,
	* const struct ndisc_options *ndopts):
	* This function is called when IPv6 ndisc updates the neighbour cache
	* entry. Additional options which can be updated may be previously
	* parsed by parse_opts callback and accessible over ndopts parameter.
	*
	* int (opt_addr_space)(const struct net_device dev, u8 icmp6_type,
	* struct neighbour neigh, u8 ha_buf,
	* u8 **ha):
	* This function is called when the necessary option space will be
	* calculated before allocating a skb. The parameters neigh, ha_buf
	* abd ha are available on NDISC_REDIRECT messages only.
	*
	* void (fill_addr_option)(const struct net_device dev,
	* struct sk_buff *skb, u8 icmp6_type,
	* const u8 *ha):
	* This function is called when the skb will finally fill the option
	* fields inside skb. NOTE: this callback should fill the option
	* fields to the skb which are previously indicated by opt_space
	* parameter. That means the decision to add such option should
	* not lost between these two callbacks, e.g. protected by interface
	* up state.
	*
	* void (prefix_rcv_add_addr)(struct net net, struct net_device *dev,
	* const struct prefix_info *pinfo,
	* struct inet6_dev *in6_dev,
	* struct in6_addr *addr,
	* int addr_type, u32 addr_flags,
	* bool sllao, bool tokenized,
	* __u32 valid_lft, u32 prefered_lft,
	* bool dev_addr_generated):
	* This function is called when a RA messages is received with valid
	* PIO option fields and an IPv6 address will be added to the interface
	* for autoconfiguration. The parameter dev_addr_generated reports about
	* if the address was based on dev->dev_addr or not. This can be used
	* to add a second address if link-layer operates with two link layer
	* addresses. E.g. 802.15.4 6LoWPAN.
	*/
	struct ndisc_ops {
	int (*is_useropt)(u8 nd_opt_type);
	int (parse_options)(const struct net_device dev,
	struct nd_opt_hdr *nd_opt,
	struct ndisc_options *ndopts);
	void (update)(const struct net_device dev, struct neighbour *n,
	u32 flags, u8 icmp6_type,
	const struct ndisc_options *ndopts);
	int (opt_addr_space)(const struct net_device dev, u8 icmp6_type,
	struct neighbour neigh, u8 ha_buf,
	u8 **ha);
	void (fill_addr_option)(const struct net_device dev,
	struct sk_buff *skb, u8 icmp6_type,
	const u8 *ha);
	void (prefix_rcv_add_addr)(struct net net, struct net_device *dev,
	const struct prefix_info *pinfo,
	struct inet6_dev *in6_dev,
	struct in6_addr *addr,
	int addr_type, u32 addr_flags,
	bool sllao, bool tokenized,
	__u32 valid_lft, u32 prefered_lft,
	bool dev_addr_generated);
	};

	#if IS_ENABLED(CONFIG_IPV6)
	static inline int ndisc_ops_is_useropt(const struct net_device *dev,
	u8 nd_opt_type)
	{
	if (dev->ndisc_ops && dev->ndisc_ops->is_useropt)
	return dev->ndisc_ops->is_useropt(nd_opt_type);
	else
	return 0;
	}

	static inline int ndisc_ops_parse_options(const struct net_device *dev,
	struct nd_opt_hdr *nd_opt,
	struct ndisc_options *ndopts)
	{
	if (dev->ndisc_ops && dev->ndisc_ops->parse_options)
	return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts);
	else
	return 0;
	}

	static inline void ndisc_ops_update(const struct net_device *dev,
	struct neighbour *n, u32 flags,
	u8 icmp6_type,
	const struct ndisc_options *ndopts)
	{
	if (dev->ndisc_ops && dev->ndisc_ops->update)
	dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts);
	}

	static inline int ndisc_ops_opt_addr_space(const struct net_device *dev,
	u8 icmp6_type)
	{
	if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space &&
	icmp6_type != NDISC_REDIRECT)
	return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL,
	NULL, NULL);
	else
	return 0;
	}

	static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev,
	struct neighbour *neigh,
	u8 ha_buf, u8 *ha)
	{
	if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space)
	return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT,
	neigh, ha_buf, ha);
	else
	return 0;
	}

	static inline void ndisc_ops_fill_addr_option(const struct net_device *dev,
	struct sk_buff *skb,
	u8 icmp6_type)
	{
	if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option &&
	icmp6_type != NDISC_REDIRECT)
	dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL);
	}

	static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev,
	struct sk_buff *skb,
	const u8 *ha)
	{
	if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option)
	dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha);
	}

	static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net,
	struct net_device *dev,
	const struct prefix_info *pinfo,
	struct inet6_dev *in6_dev,
	struct in6_addr *addr,
	int addr_type, u32 addr_flags,
	bool sllao, bool tokenized,
	__u32 valid_lft,
	u32 prefered_lft,
	bool dev_addr_generated)
	{
	if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr)
	dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
	addr, addr_type,
	addr_flags, sllao,
	tokenized, valid_lft,
	prefered_lft,
	dev_addr_generated);
	}
	#endif

	/*
	* 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(unsigned char addr_len, int pad)
	{
	return NDISC_OPT_SPACE(addr_len + pad);
	}

	#if IS_ENABLED(CONFIG_IPV6)
	static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type)
	{
	return __ndisc_opt_addr_space(dev->addr_len,
	ndisc_addr_option_pad(dev->type)) +
	ndisc_ops_opt_addr_space(dev, icmp6_type);
	}

	static inline int ndisc_redirect_opt_addr_space(struct net_device *dev,
	struct neighbour *neigh,
	u8 *ops_data_buf,
	u8 **ops_data)
	{
	return __ndisc_opt_addr_space(dev->addr_len,
	ndisc_addr_option_pad(dev->type)) +
	ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf,
	ops_data);
	}
	#endif

	static inline u8 __ndisc_opt_addr_data(struct nd_opt_hdr p,
	unsigned char addr_len, int prepad)
	{
	u8 lladdr = (u8 )(p + 1);
	int lladdrlen = p->nd_opt_len << 3;
	if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad))
	return NULL;
	return lladdr + prepad;
	}

	static inline u8 ndisc_opt_addr_data(struct nd_opt_hdr p,
	struct net_device *dev)
	{
	return __ndisc_opt_addr_data(p, dev->addr_len,
	ndisc_addr_option_pad(dev->type));
	}

	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)
	{
	return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev);
	}

	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;
	}

	static inline void __ipv6_confirm_neigh(struct net_device *dev,
	const void *pkey)
	{
	struct neighbour *n;

	rcu_read_lock_bh();
	n = __ipv6_neigh_lookup_noref(dev, pkey);
	if (n) {
	unsigned long now = jiffies;

	/* avoid dirtying neighbour */
	if (n->confirmed != now)
	n->confirmed = now;
	}
	rcu_read_unlock_bh();
	}

	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, const struct in6_addr solicit,
	const struct in6_addr daddr, const struct in6_addr saddr,
	u64 nonce);

	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, 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);

	void ndisc_update(const struct net_device dev, struct neighbour neigh,
	const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
	struct ndisc_options *ndopts);

	/*
	* IGMP
	*/
	int igmp6_init(void);
	int igmp6_late_init(void);

	void igmp6_cleanup(void);
	void igmp6_late_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