/*
 * arp.h - handle ARP protocol
 *
 * Written by
 *  Christian Vogelgsang <chris@vogelgsang.org>
 *
 * This file is part of plipbox.
 * See README for copyright notice.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 *  02111-1307  USA.
 *
 */

#ifndef ARP_H
#define ARP_H

#include "global.h"
#include "net.h"

#define ARP_OFF_HW_TYPE   0
#define ARP_OFF_PROT_TYPE 2
#define ARP_OFF_HW_SIZE   4
#define ARP_OFF_PROT_SIZE 5
#define ARP_OFF_OP        6
#define ARP_OFF_SRC_MAC   8
#define ARP_OFF_SRC_IP    14
#define ARP_OFF_TGT_MAC   18
#define ARP_OFF_TGT_IP    24

#define ARP_SIZE          28

#define ARP_REQUEST       1
#define ARP_REPLY         2

extern u08 arp_is_ipv4(const u08 *buf, u16 len);
extern void arp_make_reply(u08 *buf, const u08 *my_mac, const u08 *my_ip);

/* getter */
inline u16 arp_get_op(const u08 *buf) { return net_get_word(buf + ARP_OFF_OP); }
inline const u08* arp_get_src_mac(const u08 *buf) { return buf + ARP_OFF_SRC_MAC; }
inline const u08* arp_get_src_ip(const u08 *buf) { return buf + ARP_OFF_SRC_IP; }
inline const u08* arp_get_tgt_mac(const u08 *buf) { return buf + ARP_OFF_TGT_MAC; }
inline const u08* arp_get_tgt_ip(const u08 *buf) { return buf + ARP_OFF_TGT_IP; }

#endif