nuttx/net/arp/arp_format.c

122 lines
4.4 KiB
C

/****************************************************************************
* net/arp/arp_format.c
*
* Copyright (C) 2007-2011, 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Based on uIP which also has a BSD style license:
*
* 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <string.h>
#include <debug.h>
#include <netinet/in.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/arp.h>
#include "arp/arp.h"
#ifdef CONFIG_NET_ARP
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define ETHBUF ((struct eth_hdr_s *)&dev->d_buf[0])
#define ARPBUF ((struct arp_hdr_s *)&dev->d_buf[ETH_HDRLEN])
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: arp_format
*
* Description:
* Format an ARP packet.
*
* Input Parameters:
* dev - Device structure
* ipaddr - Target IP address (32-bit)
*
* Returned Value:
* None
*
****************************************************************************/
void arp_format(FAR struct net_driver_s *dev, in_addr_t ipaddr)
{
FAR struct arp_hdr_s *arp = ARPBUF;
FAR struct eth_hdr_s *eth = ETHBUF;
/* Construct the ARP packet. Creating both the Ethernet and ARP headers */
memset(eth->dest, 0xff, ETHER_ADDR_LEN);
memset(arp->ah_dhwaddr, 0x00, ETHER_ADDR_LEN);
memcpy(eth->src, dev->d_mac.ether_addr_octet, ETHER_ADDR_LEN);
memcpy(arp->ah_shwaddr, dev->d_mac.ether_addr_octet, ETHER_ADDR_LEN);
net_ipaddr_hdrcopy(arp->ah_dipaddr, &ipaddr);
net_ipaddr_hdrcopy(arp->ah_sipaddr, &dev->d_ipaddr);
arp->ah_opcode = HTONS(ARP_REQUEST);
arp->ah_hwtype = HTONS(ARP_HWTYPE_ETH);
arp->ah_protocol = HTONS(ETHTYPE_IP);
arp->ah_hwlen = ETHER_ADDR_LEN;
arp->ah_protolen = 4;
eth->type = HTONS(ETHTYPE_ARP);
dev->d_len = sizeof(struct arp_hdr_s) + ETH_HDRLEN;
}
#endif /* CONFIG_NET_ARP */