/*      $OpenBSD: ip_icmp.h,v 1.33 2025/03/02 21:28:32 bluhm Exp $      */
/*      $NetBSD: ip_icmp.h,v 1.10 1996/02/13 23:42:28 christos Exp $    */

/*
 * 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_IP_ICMP_H_
#define _NETINET_IP_ICMP_H_

/*
 * Interface Control Message Protocol Definitions.
 * Per RFC 792, September 1981.
 * RFC 950, August 1985. (Address Mask Request / Reply)
 * RFC 1256, September 1991. (Router Advertisement and Solicitation)
 * RFC 1108, November 1991. (Param Problem, Missing Req. Option)
 * RFC 1393, January 1993. (Traceroute)
 * RFC 1475, June 1993. (Datagram Conversion Error)
 * RFC 1812, June 1995. (adm prohib, host precedence, precedence cutoff)
 * RFC 2002, October 1996. (Mobility changes to Router Advertisement)
 */

/*
 * ICMP Router Advertisement data
 */
struct icmp_ra_addr {
        u_int32_t ira_addr;
        u_int32_t ira_preference;
};

/*
 * Structure of an icmp header.
 */
struct icmp {
        u_int8_t  icmp_type;            /* type of message, see below */
        u_int8_t  icmp_code;            /* type sub code */
        u_int16_t icmp_cksum;           /* ones complement cksum of struct */
        union {
                u_int8_t  ih_pptr;      /* ICMP_PARAMPROB */
                struct ih_exthdr {      /* RFC4884 extended header */
                        u_int8_t  iex_pad;
                        u_int8_t  iex_length;
                } ih_exthdr;
                struct in_addr ih_gwaddr;       /* ICMP_REDIRECT */
                struct ih_idseq {
                          u_int16_t icd_id;
                          u_int16_t icd_seq;
                } ih_idseq;
                int32_t   ih_void;

                /* ICMP_UNREACH_NEEDFRAG -- Path MTU Discovery (RFC1191) */
                struct ih_pmtu {
                          u_int16_t ipm_void;
                          u_int16_t ipm_nextmtu;
                } ih_pmtu;

                struct ih_rtradv {
                        u_int8_t irt_num_addrs;
                        u_int8_t irt_wpa;
                        u_int16_t irt_lifetime;
                } ih_rtradv;
        } icmp_hun;
#define icmp_pptr         icmp_hun.ih_pptr
#define icmp_length       icmp_hun.ih_exthdr.iex_length
#define icmp_gwaddr       icmp_hun.ih_gwaddr
#define icmp_id           icmp_hun.ih_idseq.icd_id
#define icmp_seq          icmp_hun.ih_idseq.icd_seq
#define icmp_void         icmp_hun.ih_void
#define icmp_pmvoid       icmp_hun.ih_pmtu.ipm_void
#define icmp_nextmtu      icmp_hun.ih_pmtu.ipm_nextmtu
#define icmp_num_addrs    icmp_hun.ih_rtradv.irt_num_addrs
#define icmp_wpa          icmp_hun.ih_rtradv.irt_wpa
#define icmp_lifetime     icmp_hun.ih_rtradv.irt_lifetime
        union {
                struct id_ts {
                          u_int32_t its_otime;
                          u_int32_t its_rtime;
                          u_int32_t its_ttime;
                } id_ts;
                struct id_ip  {
                          struct ip idi_ip;
                          /* options and then 64 bits of data */
                } id_ip;
                u_int32_t id_mask;
                int8_t    id_data[1];
        } icmp_dun;
#define icmp_otime        icmp_dun.id_ts.its_otime
#define icmp_rtime        icmp_dun.id_ts.its_rtime
#define icmp_ttime        icmp_dun.id_ts.its_ttime
#define icmp_ip           icmp_dun.id_ip.idi_ip
#define icmp_mask         icmp_dun.id_mask
#define icmp_data         icmp_dun.id_data
};

struct icmp_ext_hdr {
        u_int8_t  ieh_version;          /* only high nibble used */
        u_int8_t  ieh_res;              /* reserved, must be zero */
        u_int16_t ieh_cksum;            /* ones complement cksum of ext hdr */
};

#define ICMP_EXT_HDR_VERSION    0x20
#define ICMP_EXT_HDR_VMASK      0xf0
#define ICMP_EXT_OFFSET         128

struct icmp_ext_obj_hdr {
        u_int16_t ieo_length;           /* length of obj incl this header */
        u_int8_t  ieo_cnum;             /* class number */
        u_int8_t  ieo_ctype;            /* sub class type */
};

#define ICMP_EXT_MPLS           1
#define ICMP_EXT_IFINFO         2

/*
 * For IPv6 transition related ICMP errors.
 */
#define ICMP_V6ADVLENMIN        (8 + sizeof(struct ip) + 40)
#define ICMP_V6ADVLEN(p)        (8 + ((p)->icmp_ip.ip_hl << 2) + 40)

/*
 * Lower bounds on packet lengths for various types.
 * For the error advice packets must first insure that the
 * packet is large enough to contain the returned ip header.
 * Only then can we do the check to see if 64 bits of packet
 * data have been returned, since we need to check the returned
 * ip header length.
 */
#define ICMP_MINLEN     8                               /* abs minimum */
#define ICMP_TSLEN      (8 + 3 * sizeof (u_int32_t))    /* timestamp */
#define ICMP_MASKLEN    12                              /* address mask */
#define ICMP_ADVLENMIN  (8 + sizeof (struct ip) + 8)    /* min */
#define ICMP_ADVLENMAX  (8 + 60 + 40)                   /* maximum */
#define ICMP_ADVLEN(p)  (8 + ((p)->icmp_ip.ip_hl << 2) + 8)
        /* N.B.: must separately check that ip_hl >= 5 */

/*
 * Definition of type and code field values.
 *      https://www.iana.org/assignments/icmp-parameters
 */
#define ICMP_ECHOREPLY          0               /* echo reply */
#define ICMP_UNREACH            3               /* dest unreachable, codes: */
#define         ICMP_UNREACH_NET                0       /* bad net */
#define         ICMP_UNREACH_HOST               1       /* bad host */
#define         ICMP_UNREACH_PROTOCOL           2       /* bad protocol */
#define         ICMP_UNREACH_PORT               3       /* bad port */
#define         ICMP_UNREACH_NEEDFRAG           4       /* IP_DF caused drop */
#define         ICMP_UNREACH_SRCFAIL            5       /* src route failed */
#define         ICMP_UNREACH_NET_UNKNOWN        6       /* unknown net */
#define         ICMP_UNREACH_HOST_UNKNOWN       7       /* unknown host */
#define         ICMP_UNREACH_ISOLATED           8       /* src host isolated */
#define         ICMP_UNREACH_NET_PROHIB         9       /* for crypto devs */
#define         ICMP_UNREACH_HOST_PROHIB        10      /* ditto */
#define         ICMP_UNREACH_TOSNET             11      /* bad tos for net */
#define         ICMP_UNREACH_TOSHOST            12      /* bad tos for host */
#define         ICMP_UNREACH_FILTER_PROHIB      13      /* prohibited access */
#define         ICMP_UNREACH_HOST_PRECEDENCE    14      /* precedence violat'n*/
#define         ICMP_UNREACH_PRECEDENCE_CUTOFF  15      /* precedence cutoff */
#define ICMP_SOURCEQUENCH       4               /* packet lost, slow down */
#define ICMP_REDIRECT           5               /* shorter route, codes: */
#define         ICMP_REDIRECT_NET       0               /* for network */
#define         ICMP_REDIRECT_HOST      1               /* for host */
#define         ICMP_REDIRECT_TOSNET    2               /* for tos and net */
#define         ICMP_REDIRECT_TOSHOST   3               /* for tos and host */
#define ICMP_ALTHOSTADDR        6               /* alternate host address */
#define ICMP_ECHO               8               /* echo service */
#define ICMP_ROUTERADVERT       9               /* router advertisement */
#define         ICMP_ROUTERADVERT_NORMAL                0       /* normal advertisement */
#define         ICMP_ROUTERADVERT_NOROUTE_COMMON        16      /* selective routing */
#define ICMP_ROUTERSOLICIT      10              /* router solicitation */
#define ICMP_TIMXCEED           11              /* time exceeded, code: */
#define         ICMP_TIMXCEED_INTRANS   0               /* ttl==0 in transit */
#define         ICMP_TIMXCEED_REASS     1               /* ttl==0 in reass */
#define ICMP_PARAMPROB          12              /* ip header bad */
#define         ICMP_PARAMPROB_ERRATPTR 0               /* req. opt. absent */
#define         ICMP_PARAMPROB_OPTABSENT 1              /* req. opt. absent */
#define         ICMP_PARAMPROB_LENGTH   2               /* bad length */
#define ICMP_TSTAMP             13              /* timestamp request */
#define ICMP_TSTAMPREPLY        14              /* timestamp reply */
#define ICMP_IREQ               15              /* information request */
#define ICMP_IREQREPLY          16              /* information reply */
#define ICMP_MASKREQ            17              /* address mask request */
#define ICMP_MASKREPLY          18              /* address mask reply */
#define ICMP_TRACEROUTE         30              /* traceroute */
#define ICMP_DATACONVERR        31              /* data conversion error */
#define ICMP_MOBILE_REDIRECT    32              /* mobile host redirect */
#define ICMP_IPV6_WHEREAREYOU   33              /* IPv6 where-are-you */
#define ICMP_IPV6_IAMHERE       34              /* IPv6 i-am-here */
#define ICMP_MOBILE_REGREQUEST  35              /* mobile registration req */
#define ICMP_MOBILE_REGREPLY    36              /* mobile registration reply */
#define ICMP_SKIP               39              /* SKIP */
#define ICMP_PHOTURIS           40              /* Photuris */
#define         ICMP_PHOTURIS_UNKNOWN_INDEX     1       /* unknown sec index */
#define         ICMP_PHOTURIS_AUTH_FAILED       2       /* auth failed */
#define         ICMP_PHOTURIS_DECRYPT_FAILED    3       /* decrypt failed */

#define ICMP_MAXTYPE            40

#define ICMP_INFOTYPE(type) \
        ((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \
        (type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \
        (type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \
        (type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \
        (type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY)

#ifdef _KERNEL
struct mbuf *
        icmp_do_error(struct mbuf *, int, int, u_int32_t, int);
void    icmp_error(struct mbuf *, int, int, u_int32_t, int);
int     icmp_input(struct mbuf **, int *, int, int, struct netstack *);
void    icmp_init(void);
int     icmp_reflect(struct mbuf *, struct mbuf **, struct in_ifaddr *);
void    icmp_send(struct mbuf *, struct mbuf *);
int     icmp_sysctl(int *, u_int, void *, size_t *, void *, size_t);
struct rtentry *
        icmp_mtudisc_clone(struct in_addr, u_int, int);
void    icmp_mtudisc(struct icmp *, u_int);
int     icmp_do_exthdr(struct mbuf *, u_int16_t, u_int8_t, void *, size_t);
#endif /* _KERNEL */
#endif /* _NETINET_IP_ICMP_H_ */