incubator-nuttx/net/neighbor/neighbor_add.c

143 lines
4.4 KiB
C

/****************************************************************************
* net/neighbor/neighbor_add.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <string.h>
#include <assert.h>
#include <debug.h>
#include <net/if.h>
#include <nuttx/net/net.h>
#include <nuttx/net/ip.h>
#include <nuttx/net/neighbor.h>
#include "netdev/netdev.h"
#include "netlink/netlink.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:
* dev - Driver instance associated with the MAC
* ipaddr - The IPv6 address of the mapping.
* addr - The link layer address of the mapping
*
* Returned Value:
* None
*
****************************************************************************/
void neighbor_add(FAR struct net_driver_s *dev, FAR net_ipv6addr_t ipaddr,
FAR uint8_t *addr)
{
uint8_t lltype;
clock_t oldest_time;
int oldest_ndx;
bool found = false;
bool new_entry;
int i;
DEBUGASSERT(dev != NULL && addr != NULL);
/* Find the matching entry, first unused entry, or the oldest used entry.
* The unused entry will have ne_time == 0 and should generate the oldest
* time. REVISIT: Could this fail on clock wraparound? A more explicit
* check might be to compare ne_ipaddr with the IPv6 unspecified address.
*/
oldest_time = g_neighbors[0].ne_time;
oldest_ndx = 0;
lltype = dev->d_lltype;
for (i = 0; i < CONFIG_NET_IPv6_NCONF_ENTRIES; ++i)
{
if (g_neighbors[i].ne_addr.na_lltype == lltype &&
net_ipv6addr_cmp(g_neighbors[i].ne_ipaddr, ipaddr))
{
oldest_ndx = i;
found = true;
break;
}
if ((int)(g_neighbors[i].ne_time - oldest_time) < 0)
{
oldest_ndx = i;
oldest_time = g_neighbors[i].ne_time;
}
}
/* When overwite old entry, need to notify RTM_DELNEIGH */
if (!found && g_neighbors[oldest_ndx].ne_time != 0)
{
netlink_neigh_notify(&g_neighbors[oldest_ndx], RTM_DELNEIGH,
AF_INET6);
}
/* Need to notify when entry is not found or changes in table */
new_entry = !found || memcmp(&g_neighbors[oldest_ndx].ne_addr.u, addr,
g_neighbors[oldest_ndx].ne_addr.na_llsize) != 0;
/* Use the oldest or first free entry (either pointed to by the
* "oldest_ndx" variable).
*/
g_neighbors[oldest_ndx].ne_dev = dev;
g_neighbors[oldest_ndx].ne_time = clock_systime_ticks();
net_ipv6addr_copy(g_neighbors[oldest_ndx].ne_ipaddr, ipaddr);
g_neighbors[oldest_ndx].ne_addr.na_lltype = lltype;
g_neighbors[oldest_ndx].ne_addr.na_llsize = netdev_lladdrsize(dev);
memcpy(&g_neighbors[oldest_ndx].ne_addr.u, addr,
g_neighbors[oldest_ndx].ne_addr.na_llsize);
/* Notify the new entry */
if (new_entry)
{
netlink_neigh_notify(&g_neighbors[oldest_ndx], RTM_NEWNEIGH,
AF_INET6);
}
/* Dump the contents of the new entry */
neighbor_dumpentry("Added entry", &g_neighbors[oldest_ndx]);
}