arp.h

/*
 * Copyright (c) 2001, Swedish Institute of Computer Science.
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the Swedish Institute
 *      of Computer Science and its contributors.
 * 4. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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. 
 *
 * This file is part of the lwIP TCP/IP stack.
 * 
 * Author: Adam Dunkels <adam@sics.se>
 *
 * $Id$
 *
 */

#ifndef __NETIF_ARP_H__
#define __NETIF_ARP_H__

#include "net/pbuf.h"
#include "net/ipv4/ip_addr.h"
#include "net/netif.h"

struct eth_addr {
  PACK_STRUCT_FIELD(uInt8 addr[6]);
} PACK_STRUCT_STRUCT;
  
struct eth_hdr {
  PACK_STRUCT_FIELD(struct eth_addr dest);
  PACK_STRUCT_FIELD(struct eth_addr src);
  PACK_STRUCT_FIELD(uInt16 type);
} PACK_STRUCT_STRUCT;

#define ARP_TMR_INTERVAL 10000

#define ETHTYPE_ARP 0x0806
#define ETHTYPE_IP  0x0800

/* Initializes ARP. */
void arp_init(void);

/* The arp_tmr() function should be called every ARP_TMR_INTERVAL
   microseconds (10 seconds). This function is responsible for
   expiring old entries in the ARP table. */
void arp_tmr(void);

/* Should be called for all incoming packets of IP kind. The function
   does not alter the packet in any way, it just updates the ARP
   table. After this function has been called, the normal TCP/IP stack
   input function should be called. */
void arp_ip_input(struct netif *netif, struct pbuf *p);

/* Should be called for incoming ARP packets. The pbuf in the argument
   is freed by this function. If the function returns a pbuf (i.e.,
   returns non-NULL), that pbuf constitutes an ARP reply and should be
   sent out on the Ethernet. */
struct pbuf *arp_arp_input(struct netif *netif, struct eth_addr *ethaddr,
                           struct pbuf *p);

/* arp_loopup() is called to do an IP address -> Ethernet address
   translation. If the function returns NULL, there is no mapping and
   the arp_query() function should be called. */
struct eth_addr *arp_lookup(struct ip_addr *ipaddr);

/* Constructs an ARP query packet for the given IP address. The
   function returns a pbuf that contains the reply and that should be
   sent out on the Ethernet. */
struct pbuf *arp_query(struct netif *netif, struct eth_addr *ethaddr,
                       struct ip_addr *ipaddr);

#endif /* __NETIF_ARP_H__ */

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