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incubator-nuttx/net/icmpv6/icmpv6_neighbor.c

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/****************************************************************************
* net/icmpv6/icmpv6_neighbor.c
*
* Copyright (C) 2015 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 NuttX 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 COPYRIGHT HOLDERS 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
* COPYRIGHT OWNER 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 <unistd.h>
#include <string.h>
#include <semaphore.h>
#include <time.h>
#include <debug.h>
#include <netinet/in.h>
#include <net/if.h>
#include <nuttx/net/net.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/ip.h>
#include <nuttx/net/icmpv6.h>
#include "netdev/netdev.h"
#include "devif/devif.h"
#include "neighbor/neighbor.h"
#include "icmpv6/icmpv6.h"
#ifdef CONFIG_NET_ICMPv6_NEIGHBOR
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define CONFIG_ICMPv6_NEIGHBOR_DELAYSEC \
(CONFIG_ICMPv6_NEIGHBOR_DELAYMSEC / 1000)
#define CONFIG_ICMPv6_NEIGHBOR_DELAYNSEC \
((CONFIG_ICMPv6_NEIGHBOR_DELAYMSEC - 1000*CONFIG_ICMPv6_NEIGHBOR_DELAYSEC) * 1000000)
/****************************************************************************
* Private Types
****************************************************************************/
/* This structure holds the state of the send operation until it can be
* operated upon from the interrupt level.
*/
struct icmpv6_neighbor_s
{
FAR struct devif_callback_s *snd_cb; /* Reference to callback instance */
sem_t snd_sem; /* Used to wake up the waiting thread */
uint8_t snd_retries; /* Retry count */
volatile bool snd_sent; /* True: if request sent */
#ifdef CONFIG_NETDEV_MULTINIC
uint8_t snd_ifname[IFNAMSIZ]; /* Interface name */
#endif
net_ipv6addr_t snd_ipaddr; /* The IPv6 address to be queried */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: icmpv6_neighbor_interrupt
****************************************************************************/
static uint16_t icmpv6_neighbor_interrupt(FAR struct net_driver_s *dev,
FAR void *pvconn,
FAR void *priv, uint16_t flags)
{
FAR struct icmpv6_neighbor_s *state = (FAR struct icmpv6_neighbor_s *)priv;
nllvdbg("flags: %04x sent: %d\n", flags, state->snd_sent);
if (state)
{
#ifdef CONFIG_NETDEV_MULTINIC
/* Is this the device that we need to route this request? */
if (strncmp((FAR const char *)dev->d_ifname,
(FAR const char *)state->snd_ifname, IFNAMSIZ) != 0)
{
/* No... pass on this one and wait for the device that we want */
return flags;
}
#endif
/* Check if the outgoing packet is available. It may have been claimed
* by a send interrupt serving a different thread -OR- if the output
* buffer currently contains unprocessed incoming data. In these cases
* we will just have to wait for the next polling cycle.
*/
if (dev->d_sndlen > 0 || (flags & ICMPv6_NEWDATA) != 0)
{
/* Another thread has beat us sending data or the buffer is busy,
* Check for a timeout. If not timed out, wait for the next
* polling cycle and check again.
*/
/* REVISIT: No timeout. Just wait for the next polling cycle */
return flags;
}
/* It looks like we are good to send the data */
/* Copy the packet data into the device packet buffer and send it */
icmpv6_solicit(dev, state->snd_ipaddr);
/* Make sure no additional Neighbor Solicitation overwrites this one.
* This flag will be cleared in icmpv6_out().
*/
IFF_SET_NOARP(dev->d_flags);
/* Don't allow any further call backs. */
state->snd_sent = true;
state->snd_cb->flags = 0;
state->snd_cb->priv = NULL;
state->snd_cb->event = NULL;
/* Wake up the waiting thread */
sem_post(&state->snd_sem);
}
return flags;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: icmpv6_neighbor
*
* Description:
* The icmpv6_solicit() call may be to send an ICMPv6 Neighbor
* Solicitation to resolve an IPv6 address. This function first checks if
* the IPv6 address is already in the Neighbor Table. If so, then it
* returns success immediately.
*
* If the requested IPv6 address in not in the Neighbor Table, then this
* function will send the Neighbor Solicitation, delay, then check if the
* IP address is now in the Neighbor able. It will repeat this sequence
* until either (1) the IPv6 address mapping is now in the Neighbor table,
* or (2) a configurable number of timeouts occur without receiving the
* ICMPv6 Neighbor Advertisement.
*
* Parameters:
* ipaddr The IPv6 address to be queried.
*
* Returned Value:
* Zero (OK) is returned on success and the IP address mapping can now be
* found in the Neighbor Table. On error a negated errno value is returned:
*
* -ETIMEDOUT: The number or retry counts has been exceed.
* -EHOSTUNREACH: Could not find a route to the host
*
* Assumptions:
* This function is called from the normal tasking context.
*
****************************************************************************/
int icmpv6_neighbor(const net_ipv6addr_t ipaddr)
{
FAR struct net_driver_s *dev;
struct icmpv6_notify_s notify;
struct timespec delay;
struct icmpv6_neighbor_s state;
FAR const uint16_t *lookup;
net_lock_t save;
int ret;
/* First check if destination is a local broadcast or a multicast address.
*
* - IPv6 multicast addresses are have the high-order octet of the
* addresses=0xff (ff00::/8.)
*/
if (net_ipv6addr_cmp(ipaddr, g_ipv6_allzeroaddr) ||
(ipaddr[0] & NTOHS(0xff00)) == NTOHS(0xff00))
{
/* We don't need to send the Neighbor Solicitation */
return OK;
}
/* Get the device that can route this request */
#ifdef CONFIG_NETDEV_MULTINIC
dev = netdev_findby_ipv6addr(g_ipv6_allzeroaddr, ipaddr);
#else
dev = netdev_findby_ipv6addr(ipaddr);
#endif
if (!dev)
{
ndbg("ERROR: Unreachable: %08lx\n", (unsigned long)ipaddr);
ret = -EHOSTUNREACH;
goto errout;
}
#ifdef CONFIG_NET_MULTILINK
/* If we are supporting multiple network devices and using different
* link level protocols then we can get here for other link protocols
* as well. Continue and send the Neighbor Solicitation request only
* if this device uses the Ethernet data link protocol.
*
* REVISIT: Other link layer protocols may require Neighbor Discovery
* as well (but not SLIP which is the only other option at the moment).
*/
if (dev->d_lltype != NET_LL_ETHERNET)
{
return OK;
}
#endif
/* Check if the destination address is on the local network. */
if (net_ipv6addr_maskcmp(ipaddr, dev->d_ipv6addr, dev->d_ipv6netmask))
{
/* Yes.. use the input address for the lookup */
lookup = ipaddr;
}
else
{
net_ipv6addr_t dripaddr;
/* Destination address is not on the local network */
#ifdef CONFIG_NET_ROUTE
/* We have a routing table.. find the correct router to use in
* this case (or, as a fall-back, use the device's default router
* address). We will use the router IP address instead of the
* destination address when determining the MAC address.
*/
netdev_ipv6_router(dev, ipaddr, dripaddr);
#else
/* Use the device's default router IP address instead of the
* destination address when determining the MAC address.
*/
net_ipv6addr_copy(dripaddr, dev->d_ipv6draddr);
#endif
/* Use the router address for the lookup */
lookup = dripaddr;
}
/* Allocate resources to receive a callback. This and the following
* initialization is performed with the network lock because we don't
* want anything to happen until we are ready.
*/
save = net_lock();
state.snd_cb = icmpv6_callback_alloc(dev);
if (!state.snd_cb)
{
ndbg("ERROR: Failed to allocate a cllback\n");
ret = -ENOMEM;
goto errout_with_lock;
}
/* Initialize the state structure. This is done with interrupts
* disabled
*/
(void)sem_init(&state.snd_sem, 0, 0); /* Doesn't really fail */
state.snd_retries = 0; /* No retries yet */
net_ipv6addr_copy(state.snd_ipaddr, lookup); /* IP address to query */
#ifdef CONFIG_NETDEV_MULTINIC
/* Remember the routing device name */
strncpy((FAR char *)state.snd_ifname, (FAR const char *)dev->d_ifname,
IFNAMSIZ);
#endif
/* Now loop, testing if the address mapping is in the Neighbor Table and
* re-sending the Neighbor Solicitation if it is not.
*/
ret = -ETIMEDOUT; /* Assume a timeout failure */
while (state.snd_retries < CONFIG_ICMPv6_NEIGHBOR_MAXTRIES)
{
/* Check if the address mapping is present in the Neighbor Table. This
* is only really meaningful on the first time through the loop.
*
* NOTE: If the Neighbor Table is large than this could be a performance
* issue.
*/
if (neighbor_findentry(lookup) != NULL)
{
/* We have it! Break out with success */
ret = OK;
break;
}
/* Set up the Neighbor Advertisement wait BEFORE we send the Neighbor
* Solicitation.
*/
icmpv6_wait_setup(lookup, &notify);
/* Arm/re-arm the callback */
state.snd_sent = false;
state.snd_cb->flags = ICMPv6_POLL;
state.snd_cb->priv = (FAR void *)&state;
state.snd_cb->event = icmpv6_neighbor_interrupt;
/* Notify the device driver that new TX data is available. */
dev->d_txavail(dev);
/* Wait for the send to complete or an error to occur: NOTES: (1)
* net_lockedwait will also terminate if a signal is received, (2)
* interrupts may be disabled! They will be re-enabled while the
* task sleeps and automatically re-enabled when the task restarts.
*/
do
{
(void)net_lockedwait(&state.snd_sem);
}
while (!state.snd_sent);
/* Now wait for response to the Neighbor Advertisement to be received.
* The optimal delay would be the work case round trip time.
* NOTE: The network is locked.
*/
delay.tv_sec = CONFIG_ICMPv6_NEIGHBOR_DELAYSEC;
delay.tv_nsec = CONFIG_ICMPv6_NEIGHBOR_DELAYNSEC;
ret = icmpv6_wait(&notify, &delay);
/* icmpv6_wait will return OK if and only if the matching Neighbor
* Advertisement is received. Otherwise, it will return -ETIMEDOUT.
*/
if (ret == OK)
{
break;
}
/* Increment the retry count */
state.snd_retries++;
}
sem_destroy(&state.snd_sem);
icmpv6_callback_free(dev, state.snd_cb);
errout_with_lock:
net_unlock(save);
errout:
return ret;
}
#endif /* CONFIG_NET_ICMPv6_NEIGHBOR */
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