if_arp.h

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/*
 * Copyright (c) 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.
 * 4. 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.
 *
 *      @(#)if_arp.h    8.1 (Berkeley) 6/10/93
 * $FreeBSD: src/sys/net/if_arp.h,v 1.21 2005/01/07 01:45:34 imp Exp $
 */


#ifndef _NET_IF_ARP_H_
#define _NET_IF_ARP_H_

#include <sys/socket.h> /* struct sockaddr */

/*
 * Address Resolution Protocol.
 *
 * See RFC 826 for protocol description.  ARP packets are variable
 * in size; the arphdr structure defines the fixed-length portion.
 * Protocol type values are the same as those for 10 Mb/s Ethernet.
 * It is followed by the variable-sized fields ar_sha, arp_spa,
 * arp_tha and arp_tpa in that order, according to the lengths
 * specified.  Field names used correspond to RFC 826.
 */
struct  arphdr {
        u_short ar_hrd;         /* format of hardware address */
#define ARPHRD_ETHER    1       /* ethernet hardware format */
#define ARPHRD_IEEE802  6       /* token-ring hardware format */
#define ARPHRD_ARCNET   7       /* arcnet hardware format */
#define ARPHRD_FRELAY   15      /* frame relay hardware format */
#define ARPHRD_IEEE1394 24      /* firewire hardware format */
        u_short ar_pro;         /* format of protocol address */
        u_char  ar_hln;         /* length of hardware address */
        u_char  ar_pln;         /* length of protocol address */
        u_short ar_op;          /* one of: */
#define ARPOP_REQUEST   1       /* request to resolve address */
#define ARPOP_REPLY     2       /* response to previous request */
#define ARPOP_REVREQUEST 3      /* request protocol address given hardware */
#define ARPOP_REVREPLY  4       /* response giving protocol address */
#define ARPOP_INVREQUEST 8      /* request to identify peer */
#define ARPOP_INVREPLY  9       /* response identifying peer */
/*
 * The remaining fields are variable in size,
 * according to the sizes above.
 */
#ifdef COMMENT_ONLY
        u_char  ar_sha[];       /* sender hardware address */
        u_char  ar_spa[];       /* sender protocol address */
        u_char  ar_tha[];       /* target hardware address */
        u_char  ar_tpa[];       /* target protocol address */
#endif
};

#define ar_sha(ap)      (((caddr_t)((ap)+1)) +   0)
#define ar_spa(ap)      (((caddr_t)((ap)+1)) +   (ap)->ar_hln)
#define ar_tha(ap)      (((caddr_t)((ap)+1)) +   (ap)->ar_hln + (ap)->ar_pln)
#define ar_tpa(ap)      (((caddr_t)((ap)+1)) + 2*(ap)->ar_hln + (ap)->ar_pln)

#define arphdr_len2(ar_hln, ar_pln)                                     \
        (sizeof(struct arphdr) + 2*(ar_hln) + 2*(ar_pln))
#define arphdr_len(ap)  (arphdr_len2((ap)->ar_hln, (ap)->ar_pln))

/*
 * ARP ioctl request
 */
struct arpreq {
        struct  sockaddr arp_pa;                /* protocol address */
        struct  sockaddr arp_ha;                /* hardware address */
        int     arp_flags;                      /* flags */
};
/*  arp_flags and at_flags field values */
#define ATF_INUSE       0x01    /* entry in use */
#define ATF_COM         0x02    /* completed entry (enaddr valid) */
#define ATF_PERM        0x04    /* permanent entry */
#define ATF_PUBL        0x08    /* publish entry (respond for other host) */
#define ATF_USETRAILERS 0x10    /* has requested trailers */

#ifdef _KERNEL
/*
 * Structure shared between the ethernet driver modules and
 * the address resolution code.  For example, each ec_softc or il_softc
 * begins with this structure.
 * The code is written so that each *_softc _must_ begin with a
 * struct arpcom, which in turn _must_ begin with a struct ifnet.
 */
struct  arpcom {
        /*
         * The ifnet struct _must_ be at the head of this structure.
         */
        struct  ifnet ac_if;            /* network-visible interface */
        u_char  ac_enaddr[6];           /* ethernet hardware address */
#if defined(__rtems__)
/* Cruft from ancient BSD - should be removed once RTEMS is updated */
        struct  ether_multi *ac_multiaddrs; /* list of ether multicast addrs */
        int     ac_multicnt;            /* length of ac_multiaddrs list */
#else
        int     now_unused;     /* XXX was length of ac_multiaddrs list */
        void    *ac_netgraph;           /* ng_ether(4) netgraph node info */
#endif
};
#define IFP2AC(ifp) ((struct arpcom *)(ifp))

#endif

#endif /* !_NET_IF_ARP_H_ */