px4-firmware/nuttx/net/uip/uip_neighbor.c

163 lines
4.4 KiB
C

/*
* uip_neighbor.c
* 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>
* 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.
*/
#include <string.h>
#include <debug.h>
#include "uip_neighbor.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)
{
uint8_t oldest_time;
int oldest;
int i;
nlldbg("Add neighbor: %02x:%02x:%02x:%02x:%02x:%02x\n",
addr->addr.ether_addr_octet[0], addr->addr.ether_addr_octet[1],
addr->addr.ether_addr_octet[2], addr->addr.ether_addr_octet[3],
addr->addr.ether_addr_octet[4], addr->addr.ether_addr_octet[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, addr))
{
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)
{
nlldbg("Lookup neighbor: %02x:%02x:%02x:%02x:%02x:%02x\n",
e->addr.addr.ether_addr_octet[0], e->addr.addr.ether_addr_octet[1],
e->addr.addr.ether_addr_octet[2], e->addr.addr.ether_addr_octet[3],
e->addr.addr.ether_addr_octet[4], e->addr.addr.ether_addr_octet[5]);
return &e->addr;
}
return NULL;
}