395 lines
12 KiB
C
395 lines
12 KiB
C
/****************************************************************************
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* net/icmpv6/icmpv6_neighbor.c
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*
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* Copyright (C) 2015-2016 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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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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*
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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
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <unistd.h>
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#include <string.h>
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#include <semaphore.h>
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#include <time.h>
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#include <debug.h>
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#include <netinet/in.h>
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#include <net/if.h>
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#include <nuttx/semaphore.h>
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#include <nuttx/net/net.h>
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#include <nuttx/net/netdev.h>
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#include <nuttx/net/ip.h>
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#include <nuttx/net/icmpv6.h>
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#include "netdev/netdev.h"
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#include "devif/devif.h"
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#include "inet/inet.h"
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#include "neighbor/neighbor.h"
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#include "route/route.h"
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#include "icmpv6/icmpv6.h"
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#ifdef CONFIG_NET_ICMPv6_NEIGHBOR
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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#define CONFIG_ICMPv6_NEIGHBOR_DELAYSEC \
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(CONFIG_ICMPv6_NEIGHBOR_DELAYMSEC / 1000)
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#define CONFIG_ICMPv6_NEIGHBOR_DELAYNSEC \
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((CONFIG_ICMPv6_NEIGHBOR_DELAYMSEC - 1000*CONFIG_ICMPv6_NEIGHBOR_DELAYSEC) * 1000000)
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/****************************************************************************
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* Private Types
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****************************************************************************/
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/* This structure holds the state of the send operation until it can be
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* operated upon from the event handler.
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*/
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struct icmpv6_neighbor_s
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{
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FAR struct devif_callback_s *snd_cb; /* Reference to callback instance */
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sem_t snd_sem; /* Used to wake up the waiting thread */
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uint8_t snd_retries; /* Retry count */
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volatile bool snd_sent; /* True: if request sent */
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uint8_t snd_ifname[IFNAMSIZ]; /* Interface name */
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net_ipv6addr_t snd_ipaddr; /* The IPv6 address to be queried */
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};
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: icmpv6_neighbor_eventhandler
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****************************************************************************/
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static uint16_t icmpv6_neighbor_eventhandler(FAR struct net_driver_s *dev,
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FAR void *pvconn,
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FAR void *priv, uint16_t flags)
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{
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FAR struct icmpv6_neighbor_s *state = (FAR struct icmpv6_neighbor_s *)priv;
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ninfo("flags: %04x sent: %d\n", flags, state->snd_sent);
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if (state)
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{
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/* Is this the device that we need to route this request? */
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if (strncmp((FAR const char *)dev->d_ifname,
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(FAR const char *)state->snd_ifname, IFNAMSIZ) != 0)
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{
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/* No... pass on this one and wait for the device that we want */
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return flags;
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}
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/* Check if the outgoing packet is available. It may have been claimed
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* by a send event handler serving a different thread -OR- if the output
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* buffer currently contains unprocessed incoming data. In these cases
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* we will just have to wait for the next polling cycle.
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*/
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if (dev->d_sndlen > 0 || (flags & ICMPv6_NEWDATA) != 0)
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{
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/* Another thread has beat us sending data or the buffer is busy,
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* Check for a timeout. If not timed out, wait for the next
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* polling cycle and check again.
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*/
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/* REVISIT: No timeout. Just wait for the next polling cycle */
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return flags;
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}
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/* It looks like we are good to send the data */
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/* Copy the packet data into the device packet buffer and send it */
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icmpv6_solicit(dev, state->snd_ipaddr);
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/* Make sure no additional Neighbor Solicitation overwrites this one.
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* This flag will be cleared in icmpv6_out().
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*/
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IFF_SET_NOARP(dev->d_flags);
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/* Don't allow any further call backs. */
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state->snd_sent = true;
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state->snd_cb->flags = 0;
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state->snd_cb->priv = NULL;
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state->snd_cb->event = NULL;
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/* Wake up the waiting thread */
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nxsem_post(&state->snd_sem);
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}
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return flags;
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: icmpv6_neighbor
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*
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* Description:
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* The icmpv6_solicit() call may be to send an ICMPv6 Neighbor
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* Solicitation to resolve an IPv6 address. This function first checks if
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* the IPv6 address is already in the Neighbor Table. If so, then it
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* returns success immediately.
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*
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* If the requested IPv6 address in not in the Neighbor Table, then this
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* function will send the Neighbor Solicitation, delay, then check if the
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* IP address is now in the Neighbor able. It will repeat this sequence
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* until either (1) the IPv6 address mapping is now in the Neighbor table,
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* or (2) a configurable number of timeouts occur without receiving the
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* ICMPv6 Neighbor Advertisement.
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*
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* Input Parameters:
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* ipaddr The IPv6 address to be queried.
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*
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* Returned Value:
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* Zero (OK) is returned on success and the IP address mapping can now be
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* found in the Neighbor Table. On error a negated errno value is returned:
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*
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* -ETIMEDOUT: The number or retry counts has been exceed.
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* -EHOSTUNREACH: Could not find a route to the host
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*
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* Assumptions:
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* This function is called from the normal tasking context.
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*
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****************************************************************************/
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int icmpv6_neighbor(const net_ipv6addr_t ipaddr)
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{
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FAR struct net_driver_s *dev;
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struct icmpv6_notify_s notify;
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struct timespec delay;
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struct icmpv6_neighbor_s state;
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FAR const uint16_t *lookup;
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int ret;
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/* First check if destination is a local broadcast or a multicast address.
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*
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* - IPv6 multicast addresses are have the high-order octet of the
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* addresses=0xff (ff00::/8.)
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*/
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if (net_ipv6addr_cmp(ipaddr, g_ipv6_unspecaddr) ||
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net_is_addr_mcast(ipaddr))
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{
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/* We don't need to send the Neighbor Solicitation */
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return OK;
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}
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/* Get the device that can route this request */
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dev = netdev_findby_ipv6addr(g_ipv6_unspecaddr, ipaddr);
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if (!dev)
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{
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nerr("ERROR: Unreachable: %08lx\n", (unsigned long)ipaddr);
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ret = -EHOSTUNREACH;
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goto errout;
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}
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/* Send the Neighbor Solicitation request only if this device uses the
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* Ethernet data link protocol.
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*
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* REVISIT: Other link layer protocols may require Neighbor Discovery
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* as well.
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*/
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if (dev->d_lltype != NET_LL_ETHERNET)
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{
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return OK;
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}
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/* Check if the destination address is on the local network. */
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if (net_ipv6addr_maskcmp(ipaddr, dev->d_ipv6addr, dev->d_ipv6netmask))
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{
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/* Yes.. use the input address for the lookup */
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lookup = ipaddr;
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}
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else
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{
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net_ipv6addr_t dripaddr;
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/* Destination address is not on the local network */
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#ifdef CONFIG_NET_ROUTE
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/* We have a routing table.. find the correct router to use in
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* this case (or, as a fall-back, use the device's default router
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* address). We will use the router IP address instead of the
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* destination address when determining the MAC address.
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*/
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netdev_ipv6_router(dev, ipaddr, dripaddr);
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#else
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/* Use the device's default router IP address instead of the
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* destination address when determining the MAC address.
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*/
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net_ipv6addr_copy(dripaddr, dev->d_ipv6draddr);
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#endif
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/* Use the router address for the lookup */
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lookup = dripaddr;
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}
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/* Allocate resources to receive a callback. This and the following
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* initialization is performed with the network lock because we don't
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* want anything to happen until we are ready.
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*/
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net_lock();
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state.snd_cb = icmpv6_callback_alloc(dev);
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if (!state.snd_cb)
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{
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nerr("ERROR: Failed to allocate a callback\n");
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ret = -ENOMEM;
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goto errout_with_lock;
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}
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/* Initialize the state structure with the network locked.
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*
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* This semaphore is used for signaling and, hence, should not have
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* priority inheritance enabled.
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*/
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(void)nxsem_init(&state.snd_sem, 0, 0); /* Doesn't really fail */
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nxsem_setprotocol(&state.snd_sem, SEM_PRIO_NONE);
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state.snd_retries = 0; /* No retries yet */
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net_ipv6addr_copy(state.snd_ipaddr, lookup); /* IP address to query */
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/* Remember the routing device name */
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strncpy((FAR char *)state.snd_ifname, (FAR const char *)dev->d_ifname,
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IFNAMSIZ);
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/* Now loop, testing if the address mapping is in the Neighbor Table and
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* re-sending the Neighbor Solicitation if it is not.
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*/
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ret = -ETIMEDOUT; /* Assume a timeout failure */
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while (state.snd_retries < CONFIG_ICMPv6_NEIGHBOR_MAXTRIES)
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{
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/* Check if the address mapping is present in the Neighbor Table. This
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* is only really meaningful on the first time through the loop.
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*
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* NOTE: If the Neighbor Table is large than this could be a performance
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* issue.
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*/
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if (neighbor_findentry(lookup) != NULL)
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{
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/* We have it! Break out with success */
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ret = OK;
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break;
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}
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/* Set up the Neighbor Advertisement wait BEFORE we send the Neighbor
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* Solicitation.
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*/
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icmpv6_wait_setup(lookup, ¬ify);
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/* Arm/re-arm the callback */
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state.snd_sent = false;
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state.snd_cb->flags = ICMPv6_POLL;
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state.snd_cb->priv = (FAR void *)&state;
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state.snd_cb->event = icmpv6_neighbor_eventhandler;
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/* Notify the device driver that new TX data is available. */
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dev->d_txavail(dev);
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/* Wait for the send to complete or an error to occur.
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* net_lockedwait will also terminate if a signal is received.
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*/
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do
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{
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(void)net_lockedwait(&state.snd_sem);
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}
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while (!state.snd_sent);
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/* Now wait for response to the Neighbor Advertisement to be received.
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* The optimal delay would be the work case round trip time.
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* NOTE: The network is locked.
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*/
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delay.tv_sec = CONFIG_ICMPv6_NEIGHBOR_DELAYSEC;
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delay.tv_nsec = CONFIG_ICMPv6_NEIGHBOR_DELAYNSEC;
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ret = icmpv6_wait(¬ify, &delay);
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/* icmpv6_wait will return OK if and only if the matching Neighbor
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* Advertisement is received. Otherwise, it will return -ETIMEDOUT.
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*/
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if (ret == OK)
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{
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break;
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}
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/* Increment the retry count */
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state.snd_retries++;
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}
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nxsem_destroy(&state.snd_sem);
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icmpv6_callback_free(dev, state.snd_cb);
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errout_with_lock:
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net_unlock();
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errout:
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return ret;
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}
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#endif /* CONFIG_NET_ICMPv6_NEIGHBOR */
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