/* * Copyright (c) 1986 Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms are permitted * provided that the above copyright notice and this paragraph are * duplicated in all such forms and that any documentation, * advertising materials, and other materials related to such * distribution and use acknowledge that the software was developed * by the University of California, Berkeley. The name of the * University may not be used to endorse or promote products derived * from this software without specific prior written permission. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. * * @(#)if_arp.h 7.3 (Berkeley) 6/27/88 */ /* * 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 address */ 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 */ /* * The remaining fields are variable in size, * according to the sizes above. */ /* 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 */ }; /* * 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 */