1 /* $OpenBSD: if_arp.h,v 1.8 2024/10/15 00:41:40 jsg Exp $ */ 2 /* $NetBSD: if_arp.h,v 1.8 1995/03/08 02:56:52 cgd Exp $ */ 3 4 /* 5 * Copyright (c) 1986, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)if_arp.h 8.1 (Berkeley) 6/10/93 33 */ 34 35 #ifndef _NET_IF_ARP_H_ 36 #define _NET_IF_ARP_H_ 37 /* 38 * Address Resolution Protocol. 39 * 40 * See RFC 826 for protocol description. ARP packets are variable 41 * in size; the arphdr structure defines the fixed-length portion. 42 * Protocol type values are the same as those for 10 Mb/s Ethernet. 43 * It is followed by the variable-sized fields ar_sha, arp_spa, 44 * arp_tha and arp_tpa in that order, according to the lengths 45 * specified. Field names used correspond to RFC 826. 46 */ 47 struct arphdr { 48 u_int16_t ar_hrd; /* format of hardware address */ 49 #define ARPHRD_ETHER 1 /* ethernet hardware format */ 50 #define ARPHRD_IEEE802 6 /* IEEE 802 hardware format */ 51 #define ARPHRD_FRELAY 15 /* frame relay hardware format */ 52 #define ARPHRD_IEEE1394 24 /* IEEE 1394 (FireWire) hardware format */ 53 u_int16_t ar_pro; /* format of protocol address */ 54 u_int8_t ar_hln; /* length of hardware address */ 55 u_int8_t ar_pln; /* length of protocol address */ 56 u_int16_t ar_op; /* one of: */ 57 #define ARPOP_REQUEST 1 /* request to resolve address */ 58 #define ARPOP_REPLY 2 /* response to previous request */ 59 #define ARPOP_REVREQUEST 3 /* request protocol address given hardware */ 60 #define ARPOP_REVREPLY 4 /* response giving protocol address */ 61 #define ARPOP_INVREQUEST 8 /* request to identify peer */ 62 #define ARPOP_INVREPLY 9 /* response identifying peer */ 63 /* 64 * The remaining fields are variable in size, 65 * according to the sizes above. 66 */ 67 #ifdef COMMENT_ONLY 68 u_int8_t ar_sha[]; /* sender hardware address */ 69 u_int8_t ar_spa[]; /* sender protocol address */ 70 u_int8_t ar_tha[]; /* target hardware address */ 71 u_int8_t ar_tpa[]; /* target protocol address */ 72 #endif 73 }; 74 #endif /* _NET_IF_ARP_H_ */ 75