/*	$NetBSD: icmp6.h,v 1.61 2024/12/06 18:36:09 riastradh Exp $	*/
/*	$KAME: icmp6.h,v 1.84 2003/04/23 10:26:51 itojun Exp $	*/


/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Copyright (c) 1982, 1986, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)ip_icmp.h	8.1 (Berkeley) 6/10/93
 */

#ifndef _NETINET_ICMP6_H_
#define _NETINET_ICMP6_H_

#include <sys/types.h>

#include <netinet/in.h>

#define ICMPV6_PLD_MAXLEN	1232	/* IPV6_MMTU - sizeof(struct ip6_hdr)
					   - sizeof(struct icmp6_hdr) */

struct icmp6_hdr {
	u_int8_t	icmp6_type;	/* type field */
	u_int8_t	icmp6_code;	/* code field */
	u_int16_t	icmp6_cksum;	/* checksum field */
	union {
		u_int32_t	icmp6_un_data32[1]; /* type-specific field */
		u_int16_t	icmp6_un_data16[2]; /* type-specific field */
		u_int8_t	icmp6_un_data8[4];  /* type-specific field */
	} icmp6_dataun;
};

#define icmp6_data32	icmp6_dataun.icmp6_un_data32
#define icmp6_data16	icmp6_dataun.icmp6_un_data16
#define icmp6_data8	icmp6_dataun.icmp6_un_data8
#define icmp6_pptr	icmp6_data32[0]		/* parameter prob */
#define icmp6_mtu	icmp6_data32[0]		/* packet too big */
#define icmp6_id	icmp6_data16[0]		/* echo request/reply */
#define icmp6_seq	icmp6_data16[1]		/* echo request/reply */
#define icmp6_maxdelay	icmp6_data16[0]		/* mcast group membership */

#define ICMP6_DST_UNREACH		1	/* dest unreachable, codes: */
#define ICMP6_PACKET_TOO_BIG		2	/* packet too big */
#define ICMP6_TIME_EXCEEDED		3	/* time exceeded, code: */
#define ICMP6_PARAM_PROB		4	/* ip6 header bad */

#define ICMP6_ECHO_REQUEST		128	/* echo service */
#define ICMP6_ECHO_REPLY		129	/* echo reply */
#define MLD_LISTENER_QUERY		130 	/* multicast listener query */
#define MLD_LISTENER_REPORT		131	/* multicast listener report */
#define MLD_LISTENER_DONE		132	/* multicast listener done */
#define MLD_LISTENER_REDUCTION MLD_LISTENER_DONE /* RFC3542 definition */

/* RFC2292 decls */
#define ICMP6_MEMBERSHIP_QUERY		130	/* group membership query */
#define ICMP6_MEMBERSHIP_REPORT		131	/* group membership report */
#define ICMP6_MEMBERSHIP_REDUCTION	132	/* group membership termination */

#ifndef _KERNEL
/* the followings are for backward compatibility to old KAME apps. */
#define MLD6_LISTENER_QUERY	MLD_LISTENER_QUERY
#define MLD6_LISTENER_REPORT	MLD_LISTENER_REPORT
#define MLD6_LISTENER_DONE	MLD_LISTENER_DONE
#endif

#define ND_ROUTER_SOLICIT		133	/* router solicitation */
#define ND_ROUTER_ADVERT		134	/* router advertisement */
#define ND_NEIGHBOR_SOLICIT		135	/* neighbor solicitation */
#define ND_NEIGHBOR_ADVERT		136	/* neighbor advertisement */
#define ND_REDIRECT			137	/* redirect */

#define ICMP6_ROUTER_RENUMBERING	138	/* router renumbering */

#define ICMP6_WRUREQUEST		139	/* who are you request */
#define ICMP6_WRUREPLY			140	/* who are you reply */
#define ICMP6_FQDN_QUERY		139	/* FQDN query */
#define ICMP6_FQDN_REPLY		140	/* FQDN reply */
#define ICMP6_NI_QUERY			139	/* node information request */
#define ICMP6_NI_REPLY			140	/* node information reply */
#define MLDV2_LISTENER_REPORT		143	/* RFC3810 listener report */

/* The definitions below are experimental. TBA */
#define MLD_MTRACE_RESP			200	/* mtrace response(to sender) */
#define MLD_MTRACE			201	/* mtrace messages */

#ifndef _KERNEL
/* the followings are for backward compatibility to old KAME apps. */
#define MLD6_MTRACE_RESP	MLD_MTRACE_RESP
#define MLD6_MTRACE		MLD_MTRACE
#endif

#define ICMP6_MAXTYPE			201

#define ICMP6_DST_UNREACH_NOROUTE	0	/* no route to destination */
#define ICMP6_DST_UNREACH_ADMIN	 	1	/* administratively prohibited */
#define ICMP6_DST_UNREACH_NOTNEIGHBOR	2	/* not a neighbor(obsolete) */
#define ICMP6_DST_UNREACH_BEYONDSCOPE	2	/* beyond scope of source address */
#define ICMP6_DST_UNREACH_ADDR		3	/* address unreachable */
#define ICMP6_DST_UNREACH_NOPORT	4	/* port unreachable */
#define ICMP6_DST_UNREACH_POLICY	5	/* source address failed ingress/egress policy */
#define ICMP6_DST_UNREACH_REJROUTE	6	/* reject route to destination */
#define ICMP6_DST_UNREACH_SOURCERT	7	/* error in source routing header */

#define ICMP6_TIME_EXCEED_TRANSIT 	0	/* ttl==0 in transit */
#define ICMP6_TIME_EXCEED_REASSEMBLY	1	/* ttl==0 in reass */

#define ICMP6_PARAMPROB_HEADER 	 	0	/* erroneous header field */
#define ICMP6_PARAMPROB_NEXTHEADER	1	/* unrecognized next header */
#define ICMP6_PARAMPROB_OPTION		2	/* unrecognized option */
#define ICMP6_PARAMPROB_FRAGMENT	3	/* incomplete chain in frag */

#define ICMP6_INFOMSG_MASK		0x80	/* all informational messages */

#define ICMP6_NI_SUBJ_IPV6	0	/* Query Subject is an IPv6 address */
#define ICMP6_NI_SUBJ_FQDN	1	/* Query Subject is a Domain name */
#define ICMP6_NI_SUBJ_IPV4	2	/* Query Subject is an IPv4 address */

#define ICMP6_NI_SUCCESS	0	/* node information successful reply */
#define ICMP6_NI_REFUSED	1	/* node information request is refused */
#define ICMP6_NI_UNKNOWN	2	/* unknown Qtype */

#define ICMP6_ROUTER_RENUMBERING_COMMAND  0	/* rr command */
#define ICMP6_ROUTER_RENUMBERING_RESULT   1	/* rr result */
#define ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET   255	/* rr seq num reset */

/* Used in kernel only */
#define ND_REDIRECT_ONLINK	0	/* redirect to an on-link node */
#define ND_REDIRECT_ROUTER	1	/* redirect to a better router */

/*
 * Multicast Listener Discovery
 */
struct mld_hdr {
	struct icmp6_hdr	mld_icmp6_hdr;
	struct in6_addr		mld_addr; /* multicast address */
};

/* definitions to provide backward compatibility to old KAME applications */
#ifndef _KERNEL
#define mld6_hdr	mld_hdr
#define mld6_type	mld_type
#define mld6_code	mld_code
#define mld6_cksum	mld_cksum
#define mld6_maxdelay	mld_maxdelay
#define mld6_reserved	mld_reserved
#define mld6_addr	mld_addr
#endif

/* shortcut macro definitions */
#define mld_type	mld_icmp6_hdr.icmp6_type
#define mld_code	mld_icmp6_hdr.icmp6_code
#define mld_cksum	mld_icmp6_hdr.icmp6_cksum
#define mld_maxdelay	mld_icmp6_hdr.icmp6_data16[0]
#define mld_reserved	mld_icmp6_hdr.icmp6_data16[1]

#define MLD_MINLEN			24

/*
 * Neighbor Discovery
 */

struct nd_router_solicit {	/* router solicitation */
	struct icmp6_hdr 	nd_rs_hdr;
	/* could be followed by options */
};

#define nd_rs_type	nd_rs_hdr.icmp6_type
#define nd_rs_code	nd_rs_hdr.icmp6_code
#define nd_rs_cksum	nd_rs_hdr.icmp6_cksum
#define nd_rs_reserved	nd_rs_hdr.icmp6_data32[0]

struct nd_router_advert {	/* router advertisement */
	struct icmp6_hdr	nd_ra_hdr;
	u_int32_t		nd_ra_reachable;	/* reachable time */
	u_int32_t		nd_ra_retransmit;	/* retransmit timer */
	/* could be followed by options */
};

#define nd_ra_type		nd_ra_hdr.icmp6_type
#define nd_ra_code		nd_ra_hdr.icmp6_code
#define nd_ra_cksum		nd_ra_hdr.icmp6_cksum
#define nd_ra_curhoplimit	nd_ra_hdr.icmp6_data8[0]
#define nd_ra_flags_reserved	nd_ra_hdr.icmp6_data8[1]
#define ND_RA_FLAG_MANAGED	0x80
#define ND_RA_FLAG_OTHER	0x40
#define ND_RA_FLAG_HOME_AGENT	0x20
#define ND_RA_FLAG_PROXY	0x04

/*
 * Router preference values based on RFC4191.
 */
#define ND_RA_FLAG_RTPREF_MASK	0x18 /* 00011000 */

#define ND_RA_FLAG_RTPREF_HIGH	0x08 /* 00001000 */
#define ND_RA_FLAG_RTPREF_MEDIUM	0x00 /* 00000000 */
#define ND_RA_FLAG_RTPREF_LOW	0x18 /* 00011000 */
#define ND_RA_FLAG_RTPREF_RSV	0x10 /* 00010000 */

#define nd_ra_router_lifetime	nd_ra_hdr.icmp6_data16[1]

struct nd_neighbor_solicit {	/* neighbor solicitation */
	struct icmp6_hdr	nd_ns_hdr;
	struct in6_addr		nd_ns_target;	/*target address */
	/* could be followed by options */
};

#define nd_ns_type		nd_ns_hdr.icmp6_type
#define nd_ns_code		nd_ns_hdr.icmp6_code
#define nd_ns_cksum		nd_ns_hdr.icmp6_cksum
#define nd_ns_reserved		nd_ns_hdr.icmp6_data32[0]

struct nd_neighbor_advert {	/* neighbor advertisement */
	struct icmp6_hdr	nd_na_hdr;
	struct in6_addr		nd_na_target;	/* target address */
	/* could be followed by options */
};

#define nd_na_type		nd_na_hdr.icmp6_type
#define nd_na_code		nd_na_hdr.icmp6_code
#define nd_na_cksum		nd_na_hdr.icmp6_cksum
#define nd_na_flags_reserved	nd_na_hdr.icmp6_data32[0]
#if BYTE_ORDER == BIG_ENDIAN
#define ND_NA_FLAG_ROUTER		0x80000000
#define ND_NA_FLAG_SOLICITED		0x40000000
#define ND_NA_FLAG_OVERRIDE		0x20000000
#else
#if BYTE_ORDER == LITTLE_ENDIAN
#define ND_NA_FLAG_ROUTER		0x80
#define ND_NA_FLAG_SOLICITED		0x40
#define ND_NA_FLAG_OVERRIDE		0x20
#endif
#endif

struct nd_redirect {		/* redirect */
	struct icmp6_hdr	nd_rd_hdr;
	struct in6_addr		nd_rd_target;	/* target address */
	struct in6_addr		nd_rd_dst;	/* destination address */
	/* could be followed by options */
};

#define nd_rd_type		nd_rd_hdr.icmp6_type
#define nd_rd_code		nd_rd_hdr.icmp6_code
#define nd_rd_cksum		nd_rd_hdr.icmp6_cksum
#define nd_rd_reserved		nd_rd_hdr.icmp6_data32[0]

struct nd_opt_hdr {		/* Neighbor discovery option header */
	u_int8_t	nd_opt_type;
	u_int8_t	nd_opt_len;
	/* followed by option specific data*/
};

#define ND_OPT_SOURCE_LINKADDR		1
#define ND_OPT_TARGET_LINKADDR		2
#define ND_OPT_PREFIX_INFORMATION	3
#define ND_OPT_REDIRECTED_HEADER	4
#define ND_OPT_MTU			5
#define ND_OPT_ADVINTERVAL		7
#define ND_OPT_HOMEAGENT_INFO		8
#define ND_OPT_SOURCE_ADDRLIST		9
#define ND_OPT_TARGET_ADDRLIST		10
#define ND_OPT_NONCE			14	/* RFC 3971 */
#define ND_OPT_MAP			23	/* RFC 5380 */
#define ND_OPT_ROUTE_INFO		24	/* RFC 4191 */
#define ND_OPT_RDNSS			25	/* RFC 6016 */
#define ND_OPT_DNSSL			31	/* RFC 6016 */
#define ND_OPT_MAX			31

struct nd_opt_route_info {	/* route info */
	u_int8_t	nd_opt_rti_type;
	u_int8_t	nd_opt_rti_len;
	u_int8_t	nd_opt_rti_prefixlen;
	u_int8_t	nd_opt_rti_flags;
	u_int32_t	nd_opt_rti_lifetime;
	/* prefix follows */
};

struct nd_opt_prefix_info {	/* prefix information */
	u_int8_t	nd_opt_pi_type;
	u_int8_t	nd_opt_pi_len;
	u_int8_t	nd_opt_pi_prefix_len;
	u_int8_t	nd_opt_pi_flags_reserved;
	u_int32_t	nd_opt_pi_valid_time;
	u_int32_t	nd_opt_pi_preferred_time;
	u_int32_t	nd_opt_pi_reserved2;
	struct in6_addr	nd_opt_pi_prefix;
};

#define ND_OPT_PI_FLAG_ONLINK		0x80
#define ND_OPT_PI_FLAG_AUTO		0x40
#define ND_OPT_PI_FLAG_ROUTER		0x20

struct nd_opt_rd_hdr {		/* redirected header */
	u_int8_t	nd_opt_rh_type;
	u_int8_t	nd_opt_rh_len;
	u_int16_t	nd_opt_rh_reserved1;
	u_int32_t	nd_opt_rh_reserved2;
	/* followed by IP header and data */
};

struct nd_opt_mtu {		/* MTU option */
	u_int8_t	nd_opt_mtu_type;
	u_int8_t	nd_opt_mtu_len;
	u_int16_t	nd_opt_mtu_reserved;
	u_int32_t	nd_opt_mtu_mtu;
};

#define	ND_OPT_NONCE_LEN	((1 * 8) - 2)
#if ((ND_OPT_NONCE_LEN + 2) % 8) != 0
#error	"(ND_OPT_NONCE_LEN + 2) must be a multiple of 8."
#endif
struct nd_opt_nonce {
	u_int8_t	nd_opt_nonce_type;
	u_int8_t	nd_opt_nonce_len;
	u_int8_t	nd_opt_nonce[ND_OPT_NONCE_LEN];
};

struct nd_opt_rdnss {		/* RDNSS option RFC 6106 */
	u_int8_t	nd_opt_rdnss_type;
	u_int8_t	nd_opt_rdnss_len;
	u_int16_t	nd_opt_rdnss_reserved;
	u_int32_t	nd_opt_rdnss_lifetime;
	/* followed by list of IP prefixes */
};

struct nd_opt_dnssl {		/* DNSSL option RFC 6106 */
	u_int8_t	nd_opt_dnssl_type;
	u_int8_t	nd_opt_dnssl_len;
	u_int16_t	nd_opt_dnssl_reserved;
	u_int32_t	nd_opt_dnssl_lifetime;
	/* followed by list of IP prefixes */
};

/*
 * icmp6 namelookup
 */

struct icmp6_namelookup {
	struct icmp6_hdr 	icmp6_nl_hdr;
	u_int8_t	icmp6_nl_nonce[8];
	int32_t		icmp6_nl_ttl;
#if 0
	u_int8_t	icmp6_nl_len;
	u_int8_t	icmp6_nl_name[3];
#endif
	/* could be followed by options */
};

/*
 * icmp6 node information
 */
struct icmp6_nodeinfo {
	struct icmp6_hdr icmp6_ni_hdr;
	u_int8_t icmp6_ni_nonce[8];
	/* could be followed by reply data */
};

#define ni_type		icmp6_ni_hdr.icmp6_type
#define ni_code		icmp6_ni_hdr.icmp6_code
#define ni_cksum	icmp6_ni_hdr.icmp6_cksum
#define ni_qtype	icmp6_ni_hdr.icmp6_data16[0]
#define ni_flags	icmp6_ni_hdr.icmp6_data16[1]

#define NI_QTYPE_NOOP		0 /* NOOP  */
#define NI_QTYPE_SUPTYPES	1 /* Supported Qtypes */
#define NI_QTYPE_FQDN		2 /* FQDN (draft 04) */
#define NI_QTYPE_DNSNAME	2 /* DNS Name */
#define NI_QTYPE_NODEADDR	3 /* Node Addresses */
#define NI_QTYPE_IPV4ADDR	4 /* IPv4 Addresses */

#if BYTE_ORDER == BIG_ENDIAN
#define NI_SUPTYPE_FLAG_COMPRESS	0x1
#define NI_FQDN_FLAG_VALIDTTL		0x1
#elif BYTE_ORDER == LITTLE_ENDIAN
#define NI_SUPTYPE_FLAG_COMPRESS	0x0100
#define NI_FQDN_FLAG_VALIDTTL		0x0100
#endif

#ifdef NAME_LOOKUPS_04
#if BYTE_ORDER == BIG_ENDIAN
#define NI_NODEADDR_FLAG_LINKLOCAL	0x1
#define NI_NODEADDR_FLAG_SITELOCAL	0x2
#define NI_NODEADDR_FLAG_GLOBAL		0x4
#define NI_NODEADDR_FLAG_ALL		0x8
#define NI_NODEADDR_FLAG_TRUNCATE	0x10
#define NI_NODEADDR_FLAG_ANYCAST	0x20 /* just experimental. not in spec */
#elif BYTE_ORDER == LITTLE_ENDIAN
#define NI_NODEADDR_FLAG_LINKLOCAL	0x0100
#define NI_NODEADDR_FLAG_SITELOCAL	0x0200
#define NI_NODEADDR_FLAG_GLOBAL		0x0400
#define NI_NODEADDR_FLAG_ALL		0x0800
#define NI_NODEADDR_FLAG_TRUNCATE	0x1000
#define NI_NODEADDR_FLAG_ANYCAST	0x2000 /* just experimental. not in spec */
#endif
#else  /* draft-ietf-ipngwg-icmp-name-lookups-05 (and later?) */
#if BYTE_ORDER == BIG_ENDIAN
#define NI_NODEADDR_FLAG_TRUNCATE	0x1
#define NI_NODEADDR_FLAG_ALL		0x2
#define NI_NODEADDR_FLAG_COMPAT		0x4
#define NI_NODEADDR_FLAG_LINKLOCAL	0x8
#define NI_NODEADDR_FLAG_SITELOCAL	0x10
#define NI_NODEADDR_FLAG_GLOBAL		0x20
#define NI_NODEADDR_FLAG_ANYCAST	0x40 /* just experimental. not in spec */
#elif BYTE_ORDER == LITTLE_ENDIAN
#define NI_NODEADDR_FLAG_TRUNCATE	0x0100
#define NI_NODEADDR_FLAG_ALL		0x0200
#define NI_NODEADDR_FLAG_COMPAT		0x0400
#define NI_NODEADDR_FLAG_LINKLOCAL	0x0800
#define NI_NODEADDR_FLAG_SITELOCAL	0x1000
#define NI_NODEADDR_FLAG_GLOBAL		0x2000
#define NI_NODEADDR_FLAG_ANYCAST	0x4000 /* just experimental. not in spec */
#endif
#endif

struct ni_reply_fqdn {
	u_int32_t ni_fqdn_ttl;	/* TTL */
	u_int8_t ni_fqdn_namelen; /* length in octets of the FQDN */
	u_int8_t ni_fqdn_name[3]; /* XXX: alignment */
};

/*
 * Router Renumbering. as router-renum-08.txt
 */
struct icmp6_router_renum {	/* router renumbering header */
	struct icmp6_hdr	rr_hdr;
	u_int8_t	rr_segnum;
	u_int8_t	rr_flags;
	u_int16_t	rr_maxdelay;
	u_int32_t	rr_reserved;
};

#define ICMP6_RR_FLAGS_TEST		0x80
#define ICMP6_RR_FLAGS_REQRESULT	0x40
#define ICMP6_RR_FLAGS_FORCEAPPLY	0x20
#define ICMP6_RR_FLAGS_SPECSITE		0x10
#define ICMP6_RR_FLAGS_PREVDONE		0x08

#define rr_type		rr_hdr.icmp6_type
#define rr_code		rr_hdr.icmp6_code
#define rr_cksum	rr_hdr.icmp6_cksum
#define rr_seqnum 	rr_hdr.icmp6_data32[0]

struct rr_pco_match {		/* match prefix part */
	u_int8_t	rpm_code;
	u_int8_t	rpm_len;
	u_int8_t	rpm_ordinal;
	u_int8_t	rpm_matchlen;
	u_int8_t	rpm_minlen;
	u_int8_t	rpm_maxlen;
	u_int16_t	rpm_reserved;
	struct	in6_addr	rpm_prefix;
};

#define RPM_PCO_ADD		1
#define RPM_PCO_CHANGE		2
#define RPM_PCO_SETGLOBAL	3
#define RPM_PCO_MAX		4

struct rr_pco_use {		/* use prefix part */
	u_int8_t	rpu_uselen;
	u_int8_t	rpu_keeplen;
	u_int8_t	rpu_ramask;
	u_int8_t	rpu_raflags;
	u_int32_t	rpu_vltime;
	u_int32_t	rpu_pltime;
	u_int32_t	rpu_flags;
	struct	in6_addr rpu_prefix;
};
#define ICMP6_RR_PCOUSE_RAFLAGS_ONLINK	0x80
#define ICMP6_RR_PCOUSE_RAFLAGS_AUTO	0x40

#if BYTE_ORDER == BIG_ENDIAN
#define ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME     0x80000000
#define ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME     0x40000000
#elif BYTE_ORDER == LITTLE_ENDIAN
#define ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME     0x80
#define ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME     0x40
#endif

struct rr_result {		/* router renumbering result message */
	u_int16_t	rrr_flags;
	u_int8_t	rrr_ordinal;
	u_int8_t	rrr_matchedlen;
	u_int32_t	rrr_ifid;
	struct	in6_addr rrr_prefix;
};
#if BYTE_ORDER == BIG_ENDIAN
#define ICMP6_RR_RESULT_FLAGS_OOB		0x0002
#define ICMP6_RR_RESULT_FLAGS_FORBIDDEN		0x0001
#elif BYTE_ORDER == LITTLE_ENDIAN
#define ICMP6_RR_RESULT_FLAGS_OOB		0x0200
#define ICMP6_RR_RESULT_FLAGS_FORBIDDEN		0x0100
#endif

/*
 * icmp6 filter structures.
 */

struct icmp6_filter {
	u_int32_t icmp6_filt[8];
};

#define	ICMP6_FILTER_SETPASSALL(filterp) \
	(void)memset(filterp, 0xff, sizeof(struct icmp6_filter))
#define	ICMP6_FILTER_SETBLOCKALL(filterp) \
	(void)memset(filterp, 0x00, sizeof(struct icmp6_filter))
#define	ICMP6_FILTER_SETPASS(type, filterp) \
	(((filterp)->icmp6_filt[(type) >> 5]) |= (1 << ((type) & 31)))
#define	ICMP6_FILTER_SETBLOCK(type, filterp) \
	(((filterp)->icmp6_filt[(type) >> 5]) &= ~(1 << ((type) & 31)))
#define	ICMP6_FILTER_WILLPASS(type, filterp) \
	((((filterp)->icmp6_filt[(type) >> 5]) & (1 << ((type) & 31))) != 0)
#define	ICMP6_FILTER_WILLBLOCK(type, filterp) \
	((((filterp)->icmp6_filt[(type) >> 5]) & (1 << ((type) & 31))) == 0)

/*
 * Variables related to this implementation
 * of the internet control message protocol version 6.
 */

/*
 * IPv6 ICMP statistics.
 * Each counter is an unsigned 64-bit value.
 */
#define	ICMP6_STAT_ERROR	0	/* # of calls to icmp6_error */
#define	ICMP6_STAT_CANTERROR	1	/* no error (old was icmp) */
#define	ICMP6_STAT_TOOFREQ	2	/* no error (rate limitation) */
#define	ICMP6_STAT_OUTHIST	3	/* # of output messages */
		/* space for 256 counters */
#define	ICMP6_STAT_BADCODE	259	/* icmp6_code out of range */
#define	ICMP6_STAT_TOOSHORT	260	/* packet < sizeof(struct icmp6_hdr) */
#define	ICMP6_STAT_CHECKSUM	261	/* bad checksum */
#define	ICMP6_STAT_BADLEN	262	/* calculated bound mismatch */
	/*
	 * number of responses; this member is inherited from the netinet code,
	 * but for netinet6 code, it is already available in outhist[].
	 */
#define	ICMP6_STAT_REFLECT	263
#define	ICMP6_STAT_INHIST	264	/* # of input messages */
		/* space for 256 counters */
#define	ICMP6_STAT_ND_TOOMANYOPT 520	/* too many ND options */
#define	ICMP6_STAT_OUTERRHIST	521
		/* space for 13 counters */
#define	ICMP6_STAT_PMTUCHG	534	/* path MTU changes */
#define	ICMP6_STAT_ND_BADOPT	535	/* bad ND options */
#define	ICMP6_STAT_BADNS	536	/* bad neighbor solicititation */
#define	ICMP6_STAT_BADNA	537	/* bad neighbor advertisement */
#define	ICMP6_STAT_BADRS	538	/* bad router solicitiation */
#define	ICMP6_STAT_BADRA	539	/* bad router advertisement */
#define	ICMP6_STAT_BADREDIRECT	540	/* bad redirect message */
#define ICMP6_STAT_DROPPED_RAROUTE 541	/* discarded routes from router advertisement */

#define	ICMP6_NSTATS		542

#define	ICMP6_ERRSTAT_DST_UNREACH_NOROUTE	0
#define	ICMP6_ERRSTAT_DST_UNREACH_ADMIN		1
#define	ICMP6_ERRSTAT_DST_UNREACH_BEYONDSCOPE	2
#define	ICMP6_ERRSTAT_DST_UNREACH_ADDR		3
#define	ICMP6_ERRSTAT_DST_UNREACH_NOPORT	4
#define	ICMP6_ERRSTAT_PACKET_TOO_BIG		5
#define	ICMP6_ERRSTAT_TIME_EXCEED_TRANSIT	6
#define	ICMP6_ERRSTAT_TIME_EXCEED_REASSEMBLY	7
#define	ICMP6_ERRSTAT_PARAMPROB_HEADER		8
#define	ICMP6_ERRSTAT_PARAMPROB_NEXTHEADER	9
#define	ICMP6_ERRSTAT_PARAMPROB_OPTION		10
#define	ICMP6_ERRSTAT_REDIRECT			11
#define	ICMP6_ERRSTAT_UNKNOWN			12

/*
 * Names for ICMP sysctl objects
 */
#define ICMPV6CTL_STATS		1
#define ICMPV6CTL_REDIRACCEPT	2	/* accept/process redirects */
#define ICMPV6CTL_REDIRTIMEOUT	3	/* redirect cache time */
#if 0	/*obsoleted*/
#define ICMPV6CTL_ERRRATELIMIT	5	/* ICMPv6 error rate limitation */
#endif
#define ICMPV6CTL_ND6_PRUNE	6
#define ICMPV6CTL_ND6_DELAY	8
#define ICMPV6CTL_ND6_UMAXTRIES	9
#define ICMPV6CTL_ND6_MMAXTRIES		10
#define ICMPV6CTL_ND6_USELOOPBACK	11
/*#define ICMPV6CTL_ND6_PROXYALL	12	obsoleted, do not reuse here */
#define ICMPV6CTL_NODEINFO	13
#define ICMPV6CTL_ERRPPSLIMIT	14	/* ICMPv6 error pps limitation */
#define ICMPV6CTL_ND6_MAXNUDHINT	15
#define ICMPV6CTL_MTUDISC_HIWAT	16
#define ICMPV6CTL_MTUDISC_LOWAT	17
#define ICMPV6CTL_ND6_DEBUG	18
#ifdef _KERNEL
#define OICMPV6CTL_ND6_DRLIST	19
#define OICMPV6CTL_ND6_PRLIST	20
#endif
#define	ICMPV6CTL_ND6_MAXQLEN	24
#define	ICMPV6CTL_REFLECT_PMTU	25
#define	ICMPV6CTL_DYNAMIC_RT_MSG	26

#ifdef _KERNEL
struct	rtentry;

void	icmp6_init(void);
void	icmp6_paramerror(struct mbuf *, int);
void	icmp6_error(struct mbuf *, int, int, int);
void	icmp6_error2(struct mbuf *, int, int, int, struct ifnet *,
	    struct in6_addr *);
int	icmp6_input(struct mbuf **, int *, int);
void	icmp6_fasttimo(void);
void	icmp6_prepare(struct mbuf *);
void	icmp6_redirect_output(struct mbuf *, struct rtentry *);
int	icmp6_sysctl(int *, u_int, void *, size_t *, void *, size_t);

void	icmp6_statinc(u_int);

struct	ip6ctlparam;
void	icmp6_mtudisc_update(struct ip6ctlparam *, int);
void	icmp6_mtudisc_callback_register(void (*)(struct in6_addr *));

/* XXX: is this the right place for these macros? */
#define icmp6_ifstat_inc(ifp, tag) \
do {								\
	if (ifp)						\
		((struct in6_ifextra *)((ifp)->if_afdata[AF_INET6]))->icmp6_ifstat->tag++; \
} while (/*CONSTCOND*/ 0)

#define icmp6_ifoutstat_inc(ifp, type, code) \
do { \
		icmp6_ifstat_inc(ifp, ifs6_out_msg); \
		switch(type) { \
		 case ICMP6_DST_UNREACH: \
			 icmp6_ifstat_inc(ifp, ifs6_out_dstunreach); \
			 if (code == ICMP6_DST_UNREACH_ADMIN) \
				 icmp6_ifstat_inc(ifp, ifs6_out_adminprohib); \
			 break; \
		 case ICMP6_PACKET_TOO_BIG: \
			 icmp6_ifstat_inc(ifp, ifs6_out_pkttoobig); \
			 break; \
		 case ICMP6_TIME_EXCEEDED: \
			 icmp6_ifstat_inc(ifp, ifs6_out_timeexceed); \
			 break; \
		 case ICMP6_PARAM_PROB: \
			 icmp6_ifstat_inc(ifp, ifs6_out_paramprob); \
			 break; \
		 case ICMP6_ECHO_REQUEST: \
			 icmp6_ifstat_inc(ifp, ifs6_out_echo); \
			 break; \
		 case ICMP6_ECHO_REPLY: \
			 icmp6_ifstat_inc(ifp, ifs6_out_echoreply); \
			 break; \
		 case MLD_LISTENER_QUERY: \
			 icmp6_ifstat_inc(ifp, ifs6_out_mldquery); \
			 break; \
		 case MLD_LISTENER_REPORT: \
			 icmp6_ifstat_inc(ifp, ifs6_out_mldreport); \
			 break; \
		 case MLD_LISTENER_DONE: \
			 icmp6_ifstat_inc(ifp, ifs6_out_mlddone); \
			 break; \
		 case ND_ROUTER_SOLICIT: \
			 icmp6_ifstat_inc(ifp, ifs6_out_routersolicit); \
			 break; \
		 case ND_ROUTER_ADVERT: \
			 icmp6_ifstat_inc(ifp, ifs6_out_routeradvert); \
			 break; \
		 case ND_NEIGHBOR_SOLICIT: \
			 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit); \
			 break; \
		 case ND_NEIGHBOR_ADVERT: \
			 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert); \
			 break; \
		 case ND_REDIRECT: \
			 icmp6_ifstat_inc(ifp, ifs6_out_redirect); \
			 break; \
		} \
} while (/*CONSTCOND*/ 0)

extern int	icmp6_rediraccept;	/* accept/process redirects */
extern int	icmp6_redirtimeout;	/* cache time for redirect routes */
#endif /* _KERNEL */

#ifdef ICMP6_STRINGS
/* Info: http://www.iana.org/assignments/icmpv6-parameters */

static const char * const icmp6_type_err[] = {
	"reserved0", "unreach", "packet_too_big", "timxceed", "paramprob",
	NULL
};

static const char * const icmp6_type_info[] = {
	"echo", "echoreply",
	"mcastlistenq", "mcastlistenrep", "mcastlistendone",
	"rtsol", "rtadv", "neighsol", "neighadv", "redirect",
	"routerrenum", "nodeinfoq", "nodeinfor", "invneighsol", "invneighrep",
	"mcastlistenrep2", "haad_req", "haad_rep",
	"mobile_psol", "mobile_padv", "cga_sol", "cga_adv",
	"experimental150", "mcast_rtadv", "mcast_rtsol", "mcast_rtterm",
	"fmipv6_msg", "rpl_control", NULL
};

static const char * const icmp6_code_none[] = { "none", NULL };

static const char * const icmp6_code_unreach[] = {
	"noroute", "admin", "beyondscope", "addr", "port",
	"srcaddr_policy", "reject_route", "source_route_err", NULL
};

static const char * const icmp6_code_timxceed[] = {
	"intrans", "reass", NULL
};

static const char * const icmp6_code_paramprob[] = {
	"hdr_field", "nxthdr_type", "option", NULL
};

/* not all informational icmps that have codes have a names array */
#endif

#endif /* !_NETINET_ICMP6_H_ */