418 lines
12 KiB
C
418 lines
12 KiB
C
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/*
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* Copyright (c) 2001-2003, Adam Dunkels.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote
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* products derived from this software without specific prior
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* written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
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* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* This file is part of the uIP TCP/IP stack.
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*
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* $Id: uip_arp.c,v 1.8 2010/12/14 22:45:22 dak664 Exp $
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*
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*/
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#include "ip64.h"
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#include "ip64-eth.h"
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#include "ip64-arp.h"
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#include <string.h>
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#include <stdio.h>
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#define printf(...)
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struct arp_hdr {
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struct ip64_eth_hdr ethhdr;
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uint16_t hwtype;
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uint16_t protocol;
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uint8_t hwlen;
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uint8_t protolen;
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uint16_t opcode;
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struct uip_eth_addr shwaddr;
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uip_ip4addr_t sipaddr;
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struct uip_eth_addr dhwaddr;
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uip_ip4addr_t dipaddr;
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};
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struct ethip_hdr {
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struct ip64_eth_hdr ethhdr;
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/* IP header. */
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uint8_t vhl,
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tos,
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len[2],
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ipid[2],
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ipoffset[2],
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ttl,
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proto;
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uint16_t ipchksum;
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uip_ip4addr_t srcipaddr, destipaddr;
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};
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struct ipv4_hdr {
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/* IP header. */
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uint8_t vhl,
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tos,
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len[2],
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ipid[2],
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ipoffset[2],
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ttl,
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proto;
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uint16_t ipchksum;
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uip_ip4addr_t srcipaddr, destipaddr;
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};
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#define ARP_REQUEST 1
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#define ARP_REPLY 2
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#define ARP_HWTYPE_ETH 1
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struct arp_entry {
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uip_ip4addr_t ipaddr;
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struct uip_eth_addr ethaddr;
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uint8_t time;
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};
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static const struct ip64_eth_addr broadcast_ethaddr =
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{{0xff,0xff,0xff,0xff,0xff,0xff}};
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static const uint16_t broadcast_ipaddr[2] = {0xffff,0xffff};
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static struct arp_entry arp_table[UIP_ARPTAB_SIZE];
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static uint8_t arptime;
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static uint8_t tmpage;
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#define DEBUG 0
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#if DEBUG
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#include <stdio.h>
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#define PRINTF(...) printf(__VA_ARGS__)
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#else
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#define PRINTF(...)
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#endif
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const uip_ipaddr_t uip_all_zeroes_addr;
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/*---------------------------------------------------------------------------*/
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/**
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* Initialize the ARP module.
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*
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*/
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/*---------------------------------------------------------------------------*/
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void
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ip64_arp_init(void)
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{
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int i;
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for(i = 0; i < UIP_ARPTAB_SIZE; ++i) {
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memset(&arp_table[i].ipaddr, 0, 4);
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}
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}
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/*---------------------------------------------------------------------------*/
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/**
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* Periodic ARP processing function.
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*
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* This function performs periodic timer processing in the ARP module
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* and should be called at regular intervals. The recommended interval
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* is 10 seconds between the calls.
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*
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*/
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/*---------------------------------------------------------------------------*/
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void
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ip64_arp_timer(void)
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{
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struct arp_entry *tabptr;
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int i;
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++arptime;
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for(i = 0; i < UIP_ARPTAB_SIZE; ++i) {
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tabptr = &arp_table[i];
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if(uip_ip4addr_cmp(&tabptr->ipaddr, &uip_all_zeroes_addr) &&
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arptime - tabptr->time >= UIP_ARP_MAXAGE) {
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memset(&tabptr->ipaddr, 0, 4);
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}
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}
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}
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/*---------------------------------------------------------------------------*/
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static void
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arp_update(uip_ip4addr_t *ipaddr, struct uip_eth_addr *ethaddr)
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{
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register struct arp_entry *tabptr = arp_table;
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int i, c;
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/* Walk through the ARP mapping table and try to find an entry to
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update. If none is found, the IP -> MAC address mapping is
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inserted in the ARP table. */
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for(i = 0; i < UIP_ARPTAB_SIZE; ++i) {
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tabptr = &arp_table[i];
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/* Only check those entries that are actually in use. */
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if(!uip_ip4addr_cmp(&tabptr->ipaddr, &uip_all_zeroes_addr)) {
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/* Check if the source IP address of the incoming packet matches
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the IP address in this ARP table entry. */
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if(uip_ip4addr_cmp(ipaddr, &tabptr->ipaddr)) {
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/* An old entry found, update this and return. */
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memcpy(tabptr->ethaddr.addr, ethaddr->addr, 6);
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tabptr->time = arptime;
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return;
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}
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}
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tabptr++;
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}
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/* If we get here, no existing ARP table entry was found, so we
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create one. */
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/* First, we try to find an unused entry in the ARP table. */
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for(i = 0; i < UIP_ARPTAB_SIZE; ++i) {
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tabptr = &arp_table[i];
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if(uip_ip4addr_cmp(&tabptr->ipaddr, &uip_all_zeroes_addr)) {
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break;
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}
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}
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/* If no unused entry is found, we try to find the oldest entry and
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throw it away. */
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if(i == UIP_ARPTAB_SIZE) {
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tmpage = 0;
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c = 0;
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for(i = 0; i < UIP_ARPTAB_SIZE; ++i) {
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tabptr = &arp_table[i];
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if(arptime - tabptr->time > tmpage) {
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tmpage = arptime - tabptr->time;
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c = i;
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}
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}
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i = c;
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tabptr = &arp_table[i];
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}
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/* Now, i is the ARP table entry which we will fill with the new
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information. */
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uip_ip4addr_copy(&tabptr->ipaddr, ipaddr);
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memcpy(tabptr->ethaddr.addr, ethaddr->addr, 6);
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tabptr->time = arptime;
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}
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/*---------------------------------------------------------------------------*/
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uint16_t
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ip64_arp_arp_input(const uint8_t *packet, uint16_t packet_len)
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{
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struct arp_hdr *arphdr = (struct arp_hdr *)packet;
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if(packet_len < sizeof(struct arp_hdr)) {
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printf("ip64_arp_arp_input: len too small %d\n", packet_len);
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return 0;
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}
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switch(arphdr->opcode) {
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case UIP_HTONS(ARP_REQUEST):
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/* ARP request. If it asked for our address, we send out a
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reply. */
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printf("ip64_arp_arp_input: request for %d.%d.%d.%d (we are %d.%d.%d.%d)\n",
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arphdr->dipaddr.u8[0], arphdr->dipaddr.u8[1],
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arphdr->dipaddr.u8[2], arphdr->dipaddr.u8[3],
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ip64_get_hostaddr()->u8[0], ip64_get_hostaddr()->u8[1],
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ip64_get_hostaddr()->u8[2], ip64_get_hostaddr()->u8[3]);
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if(uip_ip4addr_cmp(&arphdr->dipaddr, ip64_get_hostaddr())) {
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/* First, we register the one who made the request in our ARP
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table, since it is likely that we will do more communication
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with this host in the future. */
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arp_update(&arphdr->sipaddr, &arphdr->shwaddr);
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arphdr->opcode = UIP_HTONS(ARP_REPLY);
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memcpy(arphdr->dhwaddr.addr, arphdr->shwaddr.addr, 6);
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memcpy(arphdr->shwaddr.addr, ip64_eth_addr.addr, 6);
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memcpy(arphdr->ethhdr.src.addr, ip64_eth_addr.addr, 6);
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memcpy(arphdr->ethhdr.dest.addr, arphdr->dhwaddr.addr, 6);
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uip_ip4addr_copy(&arphdr->dipaddr, &arphdr->sipaddr);
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uip_ip4addr_copy(&arphdr->sipaddr, ip64_get_hostaddr());
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arphdr->ethhdr.type = UIP_HTONS(IP64_ETH_TYPE_ARP);
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return sizeof(struct arp_hdr);
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}
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break;
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case UIP_HTONS(ARP_REPLY):
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/* ARP reply. We insert or update the ARP table if it was meant
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for us. */
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if(uip_ip4addr_cmp(&arphdr->dipaddr, ip64_get_hostaddr())) {
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arp_update(&arphdr->sipaddr, &arphdr->shwaddr);
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}
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break;
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}
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return 0;
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}
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/*---------------------------------------------------------------------------*/
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int
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ip64_arp_check_cache(const uint8_t *nlhdr)
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{
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struct ipv4_hdr *ipv4_hdr = (struct ipv4_hdr *)nlhdr;
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uip_ip4addr_t broadcast_addr;
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struct arp_entry *tabptr = arp_table;
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printf("check cache %d.%d.%d.%d\n",
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uip_ipaddr_to_quad(&ipv4_hdr->destipaddr));
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/* First check if destination is a local broadcast. */
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uip_ipaddr(&broadcast_addr, 255,255,255,255);
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if(uip_ip4addr_cmp(&ipv4_hdr->destipaddr, &broadcast_addr)) {
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printf("Return 1\n");
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return 1;
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} else if(ipv4_hdr->destipaddr.u8[0] == 224) {
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/* Multicast. */
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return 1;
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} else {
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uip_ip4addr_t ipaddr;
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int i;
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/* Check if the destination address is on the local network. */
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if(!uip_ipaddr_maskcmp(&ipv4_hdr->destipaddr,
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ip64_get_hostaddr(),
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ip64_get_netmask())) {
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/* Destination address was not on the local network, so we need to
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use the default router's IP address instead of the destination
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address when determining the MAC address. */
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uip_ip4addr_copy(&ipaddr, ip64_get_draddr());
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} else {
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/* Else, we use the destination IP address. */
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uip_ip4addr_copy(&ipaddr, &ipv4_hdr->destipaddr);
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}
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for(i = 0; i < UIP_ARPTAB_SIZE; ++i) {
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if(uip_ip4addr_cmp(&ipaddr, &tabptr->ipaddr)) {
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break;
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}
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tabptr++;
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}
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if(i == UIP_ARPTAB_SIZE) {
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return 0;
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}
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return 1;
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}
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return 0;
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}
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/*---------------------------------------------------------------------------*/
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int
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ip64_arp_create_ethhdr(uint8_t *llhdr, const uint8_t *nlhdr)
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{
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struct arp_entry *tabptr = arp_table;
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struct ipv4_hdr *ipv4_hdr = (struct ipv4_hdr *)nlhdr;
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struct ip64_eth_hdr *ethhdr = (struct ip64_eth_hdr *)llhdr;
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uip_ip4addr_t broadcast_addr;
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/* Find the destination IP address in the ARP table and construct
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the Ethernet header. If the destination IP addres isn't on the
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local network, we use the default router's IP address instead.
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If not ARP table entry is found, we overwrite the original IP
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packet with an ARP request for the IP address. */
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/* First check if destination is a local broadcast. */
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uip_ipaddr(&broadcast_addr, 255,255,255,255);
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if(uip_ip4addr_cmp(&ipv4_hdr->destipaddr, &broadcast_addr)) {
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memcpy(ðhdr->dest.addr, &broadcast_ethaddr.addr, 6);
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} else if(ipv4_hdr->destipaddr.u8[0] == 224) {
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/* Multicast. */
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ethhdr->dest.addr[0] = 0x01;
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ethhdr->dest.addr[1] = 0x00;
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ethhdr->dest.addr[2] = 0x5e;
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ethhdr->dest.addr[3] = ipv4_hdr->destipaddr.u8[1];
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ethhdr->dest.addr[4] = ipv4_hdr->destipaddr.u8[2];
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ethhdr->dest.addr[5] = ipv4_hdr->destipaddr.u8[3];
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} else {
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uip_ip4addr_t ipaddr;
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int i;
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/* Check if the destination address is on the local network. */
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if(!uip_ipaddr_maskcmp(&ipv4_hdr->destipaddr,
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ip64_get_hostaddr(),
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ip64_get_netmask())) {
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/* Destination address was not on the local network, so we need to
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use the default router's IP address instead of the destination
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address when determining the MAC address. */
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uip_ip4addr_copy(&ipaddr, ip64_get_draddr());
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} else {
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/* Else, we use the destination IP address. */
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uip_ip4addr_copy(&ipaddr, &ipv4_hdr->destipaddr);
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}
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for(i = 0; i < UIP_ARPTAB_SIZE; ++i) {
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if(uip_ip4addr_cmp(&ipaddr, &tabptr->ipaddr)) {
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break;
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}
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tabptr++;
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}
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if(i == UIP_ARPTAB_SIZE) {
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return 0;
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}
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memcpy(ethhdr->dest.addr, tabptr->ethaddr.addr, 6);
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}
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memcpy(ethhdr->src.addr, ip64_eth_addr.addr, 6);
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ethhdr->type = UIP_HTONS(IP64_ETH_TYPE_IP);
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return sizeof(struct ip64_eth_hdr);
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}
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/*---------------------------------------------------------------------------*/
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int
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ip64_arp_create_arp_request(uint8_t *llhdr, const uint8_t *nlhdr)
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{
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struct ipv4_hdr *ipv4_hdr = (struct ipv4_hdr *)nlhdr;
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struct arp_hdr *arp_hdr = (struct arp_hdr *)llhdr;
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uip_ip4addr_t ipaddr;
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if(!uip_ipaddr_maskcmp(&ipv4_hdr->destipaddr,
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ip64_get_hostaddr(),
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ip64_get_netmask())) {
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/* Destination address was not on the local network, so we need to
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use the default router's IP address instead of the destination
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address when determining the MAC address. */
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uip_ip4addr_copy(&ipaddr, ip64_get_draddr());
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} else {
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/* Else, we use the destination IP address. */
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uip_ip4addr_copy(&ipaddr, &ipv4_hdr->destipaddr);
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}
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memset(arp_hdr->ethhdr.dest.addr, 0xff, 6);
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memset(arp_hdr->dhwaddr.addr, 0x00, 6);
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memcpy(arp_hdr->ethhdr.src.addr, ip64_eth_addr.addr, 6);
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memcpy(arp_hdr->shwaddr.addr, ip64_eth_addr.addr, 6);
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uip_ip4addr_copy(&arp_hdr->dipaddr, &ipaddr);
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uip_ip4addr_copy(&arp_hdr->sipaddr, ip64_get_hostaddr());
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arp_hdr->opcode = UIP_HTONS(ARP_REQUEST);
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||
|
arp_hdr->hwtype = UIP_HTONS(ARP_HWTYPE_ETH);
|
||
|
arp_hdr->protocol = UIP_HTONS(IP64_ETH_TYPE_IP);
|
||
|
arp_hdr->hwlen = 6;
|
||
|
arp_hdr->protolen = 4;
|
||
|
arp_hdr->ethhdr.type = UIP_HTONS(IP64_ETH_TYPE_ARP);
|
||
|
|
||
|
uip_appdata = &uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN];
|
||
|
|
||
|
return sizeof(struct arp_hdr);
|
||
|
}
|
||
|
/*---------------------------------------------------------------------------*/
|