/*      $NetBSD: ip_icmp.h,v 1.44 2022/05/24 20:50:20 andvar 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.
 */

/*
 * Internal of an ICMP Router Advertisement
 */
struct icmp_ra_addr {
        uint32_t ira_addr;
        uint32_t ira_preference;
};

/*
 * Structure of an icmp header.
 */
struct icmp {
        uint8_t  icmp_type;             /* type of message, see below */
        uint8_t  icmp_code;             /* type sub code */
        uint16_t icmp_cksum;            /* ones complement cksum of struct */

        union {
                int32_t ih_void;

                /* Extended Header (RFC4884) */
                struct ih_exthdr {
                        uint8_t iex_void1;
                        uint8_t iex_length;
                        uint16_t iex_void2;
                } ih_exthdr;

                /* ICMP_PARAMPROB */
                uint8_t ih_pptr;

                /* ICMP_REDIRECT */
                struct in_addr ih_gwaddr;

                /* ICMP_ECHO and friends */
                struct ih_idseq {
                        uint16_t icd_id;
                        uint16_t icd_seq;
                } ih_idseq;

                /* ICMP_UNREACH_NEEDFRAG (Path MTU Discovery, RFC1191) */
                struct ih_pmtu {
                        uint16_t ipm_void;
                        uint16_t ipm_nextmtu;
                } ih_pmtu;

                /* ICMP_ROUTERADVERT */
                struct ih_rtradv {
                        uint8_t irt_num_addrs;
                        uint8_t irt_wpa;
                        uint16_t irt_lifetime;
                } ih_rtradv;
        } icmp_hun;

#define icmp_pptr       icmp_hun.ih_pptr
#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 {
                /* ICMP_TSTAMP and friends */
                struct id_ts {
                        uint32_t its_otime;
                        uint32_t its_rtime;
                        uint32_t its_ttime;
                } id_ts;

                struct id_ip {
                        struct ip idi_ip;
                        /* options and then 64 bits of data */
                } id_ip;

                /* ICMP_ROUTERADVERT */
                struct icmp_ra_addr id_radv;

                /* ICMP_MASKREQ and friends */
                uint32_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_radv       icmp_dun.id_radv
#define icmp_mask       icmp_dun.id_mask
#define icmp_data       icmp_dun.id_data
};

#define ICMP_EXT_VERSION        2
#define ICMP_EXT_OFFSET         128

/*
 * ICMP Extension Structure Header (RFC4884).
 */
struct icmp_ext_hdr {
#if BYTE_ORDER == BIG_ENDIAN
        uint8_t version:4;
        uint8_t rsvd1:4;
#else
        uint8_t rsvd1:4;
        uint8_t version:4;
#endif
        uint8_t rsvd2;
        uint16_t checksum;
};

/*
 * ICMP Extension Object Header (RFC4884).
 */
struct icmp_ext_obj_hdr {
        uint16_t length;
        uint8_t class_num;
        uint8_t c_type;
};

#ifdef __CTASSERT
__CTASSERT(sizeof(struct icmp_ra_addr) == 8);
__CTASSERT(sizeof(struct icmp) == 28);
__CTASSERT(sizeof(struct icmp_ext_hdr) == 4);
__CTASSERT(sizeof(struct icmp_ext_obj_hdr) == 4);
#endif

/*
 * 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(uint32_t))      /* timestamp */
#define ICMP_MASKLEN    12                              /* address mask */
#define ICMP_ADVLENMIN  (8 + sizeof(struct ip) + 8)     /* min */
#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.
 */
#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               /* prohibited access */
#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_ADMIN_PROHIBIT 13          /* communication
                                                           administratively
                                                           prohibited */
#define         ICMP_UNREACH_HOST_PREC  14              /* host precedence
                                                           violation */
#define         ICMP_UNREACH_PREC_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               /* alternative host address */
#define ICMP_ECHO               8               /* echo service */
#define ICMP_ROUTERADVERT       9               /* router advertisement */
#define         ICMP_ROUTERADVERT_NORMAL 0
#define         ICMP_ROUTERADVERT_NOROUTE 16
#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
#define         ICMP_PARAMPROB_OPTABSENT 1
#define         ICMP_PARAMPROB_LENGTH   2
#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 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              /* security */
#define         ICMP_PHOTURIS_UNKNOWN_INDEX     0       /* unknown sec index */
#define         ICMP_PHOTURIS_AUTH_FAILED       1       /* auth failed */
#define         ICMP_PHOTURIS_DECOMPRESS_FAILED 2       /* decompress failed */
#define         ICMP_PHOTURIS_DECRYPT_FAILED    3       /* decrypt failed */
#define         ICMP_PHOTURIS_NEED_AUTHN        4       /* no authentication */
#define         ICMP_PHOTURIS_NEED_AUTHZ        5       /* no authorization */

#define ICMP_MAXTYPE            40
#define ICMP_NTYPES             (ICMP_MAXTYPE + 1)

#ifdef ICMP_STRINGS
static const char *icmp_type[] = {
        "echoreply", "unassigned_1", "unassigned_2", "unreach",
        "sourcequench", "redirect", "althostaddr", "unassigned_7",
        "echo", "routeradvert", "routersolicit", "timxceed",
        "paramprob", "tstamp", "tstampreply", "ireq",
        "ireqreply", "maskreq", "maskreply", "reserved_19",
        "reserved_20", "reserved_21", "reserved_22", "reserved_23",
        "reserved_24", "reserved_25", "reserved_26", "reserved_27",
        "reserved_28", "reserved_29", "traceroute", "dataconverr",
        "mobile_redirect", "ipv6_whereareyou", "ipv6_iamhere",
        "mobile_regrequest", "mobile_regreply", "reserved_37",
        "reserved_38", "skip", "photuris", NULL
};
static const char *icmp_code_none[] = { "none", NULL };
static const char *icmp_code_unreach[] = {
        "net", "host", "oprt", "needfrag", "srcfail", "net_unknown",
        "host_unknown", "isolated", "net_prohib", "host_prohib",
        "tosnet", "toshost", "admin_prohibit", "host_prec", "prec_cutoff", NULL
};
static const char *icmp_code_redirect[] = {
        "net", "host", "tosnet", "toshost", NULL
};
static const char *icmp_code_routeradvert[] = {
        "normal", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "",
        "noroute", NULL
};
static const char *icmp_code_timxceed[] = {
        "intrans", "reass", NULL
};
static const char *icmp_code_paramprob[] = {
        "erratptr", "optabsent", "length", NULL
};
static const char *icmp_code_photuris[] = {
        "unknown_index", "auth_failed", "decompress_failed",
        "decrypt_failed", "need_authn", "need_authz", NULL
};
#endif

#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
void icmp_error(struct mbuf *, int, int, n_long, int);
void icmp_mtudisc(struct icmp *, struct in_addr);
void icmp_input(struct mbuf *, int, int);
void icmp_init(void);
void icmp_reflect(struct mbuf *);

void icmp_mtudisc_callback_register(void (*)(struct in_addr));
int icmp_ratelimit(const struct in_addr *, const int, const int);
void icmp_mtudisc_lock(void);
void icmp_mtudisc_unlock(void);
#endif

#endif /* !_NETINET_IP_ICMP_H_ */