ip_icmp.h

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/*
 * 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
 * $FreeBSD: src/sys/netinet/ip_icmp.h,v 1.13 1999/08/28 00:49:24 peter Exp $
 */

#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 {
    u_int32_t ira_addr;
    u_int32_t ira_preference;
};

/*
 * Structure of an icmp header.
 */
struct icmp {
    u_char  icmp_type;      /* type of message, see below */
    u_char  icmp_code;      /* type sub code */
    u_short icmp_cksum;     /* ones complement cksum of struct */
    union {
        u_char ih_pptr;         /* ICMP_PARAMPROB */
        struct in_addr ih_gwaddr;   /* ICMP_REDIRECT */
        struct ih_idseq {
            n_short icd_id;
            n_short icd_seq;
        } ih_idseq;
        int ih_void;

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

        struct ih_rtradv {
            u_char irt_num_addrs;
            u_char irt_wpa;
            u_int16_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 {
        struct id_ts {
            n_time its_otime;
            n_time its_rtime;
            n_time its_ttime;
        } id_ts;
        struct id_ip  {
            struct ip idi_ip;
            /* options and then 64 bits of data */
        } id_ip;
        struct icmp_ra_addr id_radv;
        u_int32_t id_mask;
        char    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
};

/*
 * 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 (n_time))   /* timestamp */
#define ICMP_MASKLEN    12              /* address mask */
#define ICMP_ADVLENMIN  (8 + sizeof (struct ip) + 8)    /* min */
#ifndef _IP_VHL
#define ICMP_ADVLEN(p)  (8 + ((p)->icmp_ip.ip_hl << 2) + 8)
    /* N.B.: must separately check that ip_hl >= 5 */
#else
#define ICMP_ADVLEN(p)  (8 + (IP_VHL_HL((p)->icmp_ip.ip_vhl) << 2) + 8)
    /* N.B.: must separately check that header length >= 5 */
#endif

/*
 * 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_FILTER_PROHIB 13       /* admin prohib */
#define     ICMP_UNREACH_HOST_PRECEDENCE 14     /* host prec vio. */
#define     ICMP_UNREACH_PRECEDENCE_CUTOFF 15   /* prec 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_ECHO       8       /* echo service */
#define ICMP_ROUTERADVERT   9       /* router advertisement */
#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_OPTABSENT 1      /* req. opt. absent */
#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_MAXTYPE        18

#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 __P((struct mbuf *, int, int, n_long, struct ifnet *));
void    icmp_input __P((struct mbuf *, int));
#endif

#endif