nuttx/include/net/uip/uip-arp.h

/* uip-arp.h
 * Macros and definitions for the ARP module.
 * Author: Adam Dunkels <adam@dunkels.com>
 *
 * Copyright (c) 2001-2003, Adam Dunkels.
 * 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. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 *
 */

#ifndef __UIP_ARP_H__
#define __UIP_ARP_H__

#include <sys/types.h>
#include <nuttx/compiler.h>
#include <net/ethernet.h>
#include <net/uip/uip.h>

/* The Ethernet header -- 14 bytes. The first two fields are type 'struct
 * ether_addr but are represented as a simple byte array here because
 * some compilers refuse to pack 6 byte structures.
 */

struct uip_eth_hdr
{
  uint8  dest[6]; /* Ethernet destination address (6 bytes) */
  uint8  src[6];  /* Ethernet source address (6 bytes) */
  uint16 type;    /* Type code (2 bytes) */
};

/* Recognized values of the type bytes in the Ethernet header */

#define UIP_ETHTYPE_ARP 0x0806
#define UIP_ETHTYPE_IP  0x0800
#define UIP_ETHTYPE_IP6 0x86dd

/* The uip_arp_init() function must be called before any of the other
 * ARP functions.
 */

void uip_arp_init(void);

/* The uip_arp_ipin() function should be called whenever an IP packet
 * arrives from the Ethernet. This function refreshes the ARP table or
 * inserts a new mapping if none exists. The function assumes that an
 * IP packet with an Ethernet header is present in the d_buf buffer
 * and that the length of the packet is in the d_len field.
 */

#define uip_arp_ipin()

/* The uip_arp_arpin() should be called when an ARP packet is received
 * by the Ethernet driver. This function also assumes that the
 * Ethernet frame is present in the d_buf buffer. When the
 * uip_arp_arpin() function returns, the contents of the d_buf
 * buffer should be sent out on the Ethernet if the d_len field
 * is > 0.
 */

void uip_arp_arpin(struct uip_driver_s *dev);

/* The uip_arp_out() function should be called when an IP packet
 * should be sent out on the Ethernet. This function creates an
 * Ethernet header before the IP header in the d_buf buffer. The
 * Ethernet header will have the correct Ethernet MAC destination
 * address filled in if an ARP table entry for the destination IP
 * address (or the IP address of the default router) is present. If no
 * such table entry is found, the IP packet is overwritten with an ARP
 * request and we rely on TCP to retransmit the packet that was
 * overwritten. In any case, the d_len field holds the length of
 * the Ethernet frame that should be transmitted.
 */

void uip_arp_out(struct uip_driver_s *dev);

/* The uip_arp_timer() function should be called every ten seconds. It
 * is responsible for flushing old entries in the ARP table.
 */

void uip_arp_timer(void);

#endif /* __UIP_ARP_H__ */