incubator-nuttx/net/neighbor/neighbor_add.c

125 lines
4.4 KiB
C

/****************************************************************************
* net/neighbor/neighbor_add.c
*
* Copyright (C) 2007-2009, 2015 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* A leverage of logic from uIP which also has a BSD style license
*
* Copyright (c) 2006, Swedish Institute of Computer Science. All rights
* reserved.
* Author: Adam Dunkels <adam@sics.se>
*
* 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <string.h>
#include <debug.h>
#include <nuttx/net/ip.h>
#include "neighbor/neighbor.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: neighbor_add
*
* Description:
* Add the new address association to the Neighbor Table (if it is not
* already there).
*
* Input Parameters:
* ipaddr - The IPv6 address of the mapping.
* addr - The link layer address of the mapping
*
* Returned Value:
* None
*
****************************************************************************/
void neighbor_add(FAR net_ipv6addr_t ipaddr, FAR struct neighbor_addr_s *addr)
{
uint8_t oldest_time;
int oldest_ndx;
int i;
ninfo("Add neighbor: %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
ntohs(ipaddr[0]), ntohs(ipaddr[1]), ntohs(ipaddr[2]),
ntohs(ipaddr[3]), ntohs(ipaddr[4]), ntohs(ipaddr[5]),
ntohs(ipaddr[6]), ntohs(ipaddr[7]));
ninfo(" at: %02x:%02x:%02x:%02x:%02x:%02x\n",
addr->na_addr.ether_addr_octet[0],
addr->na_addr.ether_addr_octet[1],
addr->na_addr.ether_addr_octet[2],
addr->na_addr.ether_addr_octet[3],
addr->na_addr.ether_addr_octet[4],
addr->na_addr.ether_addr_octet[5]);
/* Find the first unused entry or the oldest used entry. */
oldest_time = 0;
oldest_ndx = 0;
for (i = 0; i < CONFIG_NET_IPv6_NCONF_ENTRIES; ++i)
{
if (g_neighbors[i].ne_time == NEIGHBOR_MAXTIME)
{
oldest_ndx = i;
break;
}
if (net_ipv6addr_cmp(g_neighbors[i].ne_ipaddr, ipaddr))
{
oldest_ndx = i;
break;
}
if (g_neighbors[i].ne_time > oldest_time)
{
oldest_ndx = i;
oldest_time = g_neighbors[i].ne_time;
}
}
/* Use the oldest or first free entry (either pointed to by the
* "oldest_ndx" variable).
*/
g_neighbors[oldest_ndx].ne_time = 0;
net_ipv6addr_copy(g_neighbors[oldest_ndx].ne_ipaddr, ipaddr);
memcpy(&g_neighbors[oldest_ndx].ne_addr, addr, sizeof(struct neighbor_addr_s));
}