nes-proj/core/net/ipv4/uip-neighbor.c

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/*
* Copyright (c) 2006, 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. 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 Contiki operating system.
*
*/
/**
* \file
* Database of link-local neighbors, used by IPv6 code and
* to be used by a future ARP code rewrite.
* \author
* Adam Dunkels <adam@sics.se>
*/
#include "net/ipv4/uip-neighbor.h"
#include <string.h>
#include <stdio.h>
#define MAX_TIME 128
#ifdef UIP_NEIGHBOR_CONF_ENTRIES
#define ENTRIES UIP_NEIGHBOR_CONF_ENTRIES
#else /* UIP_NEIGHBOR_CONF_ENTRIES */
#define ENTRIES 8
#endif /* UIP_NEIGHBOR_CONF_ENTRIES */
struct neighbor_entry {
uip_ipaddr_t ipaddr;
struct uip_neighbor_addr addr;
uint8_t time;
};
static struct neighbor_entry entries[ENTRIES];
/*---------------------------------------------------------------------------*/
void
uip_neighbor_init(void)
{
int i;
for(i = 0; i < ENTRIES; ++i) {
entries[i].time = MAX_TIME;
}
}
/*---------------------------------------------------------------------------*/
void
uip_neighbor_periodic(void)
{
int i;
for(i = 0; i < ENTRIES; ++i) {
if(entries[i].time < MAX_TIME) {
entries[i].time++;
}
}
}
/*---------------------------------------------------------------------------*/
void
uip_neighbor_add(uip_ipaddr_t *ipaddr, struct uip_neighbor_addr *addr)
{
int i, oldest;
uint8_t oldest_time;
2008-11-09 12:16:05 +00:00
/* printf("Adding neighbor with link address %02x:%02x:%02x:%02x:%02x:%02x\n",
addr->addr.addr[0], addr->addr.addr[1], addr->addr.addr[2], addr->addr.addr[3],
2008-11-09 12:16:05 +00:00
addr->addr.addr[4], addr->addr.addr[5]);*/
/* Find the first unused entry or the oldest used entry. */
oldest_time = 0;
oldest = 0;
for(i = 0; i < ENTRIES; ++i) {
if(entries[i].time == MAX_TIME) {
oldest = i;
break;
}
if(uip_ipaddr_cmp(&entries[i].ipaddr, ipaddr)) {
oldest = i;
break;
}
if(entries[i].time > oldest_time) {
oldest = i;
oldest_time = entries[i].time;
}
}
/* Use the oldest or first free entry (either pointed to by the
"oldest" variable). */
entries[oldest].time = 0;
uip_ipaddr_copy(&entries[oldest].ipaddr, ipaddr);
memcpy(&entries[oldest].addr, addr, sizeof(struct uip_neighbor_addr));
}
/*---------------------------------------------------------------------------*/
static struct neighbor_entry *
find_entry(uip_ipaddr_t *ipaddr)
{
int i;
for(i = 0; i < ENTRIES; ++i) {
if(uip_ipaddr_cmp(&entries[i].ipaddr, ipaddr)) {
return &entries[i];
}
}
return NULL;
}
/*---------------------------------------------------------------------------*/
void
uip_neighbor_update(uip_ipaddr_t *ipaddr)
{
struct neighbor_entry *e;
e = find_entry(ipaddr);
if(e != NULL) {
e->time = 0;
}
}
/*---------------------------------------------------------------------------*/
struct uip_neighbor_addr *
uip_neighbor_lookup(uip_ipaddr_t *ipaddr)
{
struct neighbor_entry *e;
e = find_entry(ipaddr);
if(e != NULL) {
/* printf("Lookup neighbor with link address %02x:%02x:%02x:%02x:%02x:%02x\n",
e->addr.addr.addr[0], e->addr.addr.addr[1], e->addr.addr.addr[2], e->addr.addr.addr[3],
e->addr.addr.addr[4], e->addr.addr.addr[5]);*/
return &e->addr;
}
return NULL;
}
/*---------------------------------------------------------------------------*/