incubator-nuttx/net/icmpv6/icmpv6_notify.c

265 lines
8.3 KiB
C

/****************************************************************************
* net/icmpv6/icmpv6_notify.c
*
* Copyright (C) 2015-2016 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 <string.h>
#include <time.h>
#include <semaphore.h>
#include <errno.h>
#include <debug.h>
#include <netinet/in.h>
#include <nuttx/irq.h>
#include <nuttx/semaphore.h>
#include <nuttx/net/net.h>
#include "icmpv6/icmpv6.h"
#ifdef CONFIG_NET_ICMPv6_NEIGHBOR
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/* List of tasks waiting for Neighbor Discover events */
static struct icmpv6_notify_s *g_icmpv6_waiters;
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: icmpv6_wait_setup
*
* Description:
* Called BEFORE an Neighbor Solicitation is sent. This function sets up
* the Neighbor Advertisement timeout before the Neighbor Solicitation
* is sent so that there is no race condition when icmpv6_wait() is called.
*
* Assumptions:
* This function is called from icmpv6_neighbor() and executes in the normal
* tasking environment.
*
****************************************************************************/
void icmpv6_wait_setup(const net_ipv6addr_t ipaddr,
FAR struct icmpv6_notify_s *notify)
{
irqstate_t flags;
/* Initialize the wait structure */
net_ipv6addr_copy(notify->nt_ipaddr, ipaddr);
notify->nt_result = -ETIMEDOUT;
/* This semaphore is used for signaling and, hence, should not have
* priority inheritance enabled.
*/
(void)nxsem_init(&notify->nt_sem, 0, 0);
nxsem_setprotocol(&notify->nt_sem, SEM_PRIO_NONE);
/* Add the wait structure to the list with interrupts disabled */
flags = enter_critical_section();
notify->nt_flink = g_icmpv6_waiters;
g_icmpv6_waiters = notify;
leave_critical_section(flags);
}
/****************************************************************************
* Name: icmpv6_wait_cancel
*
* Description:
* Cancel any wait set after icmpv6_wait_setup is called but before
* icmpv6_wait()is called (icmpv6_wait() will automatically cancel the
* wait).
*
* Assumptions:
* This function may execute in the interrupt context when called from
* icmpv6_wait().
*
****************************************************************************/
int icmpv6_wait_cancel(FAR struct icmpv6_notify_s *notify)
{
FAR struct icmpv6_notify_s *curr;
FAR struct icmpv6_notify_s *prev;
irqstate_t flags;
int ret = -ENOENT;
/* Remove our wait structure from the list (we may no longer be at the
* head of the list).
*/
flags = enter_critical_section();
for (prev = NULL, curr = g_icmpv6_waiters;
curr && curr != notify;
prev = curr, curr = curr->nt_flink);
DEBUGASSERT(curr && curr == notify);
if (curr)
{
if (prev)
{
prev->nt_flink = notify->nt_flink;
}
else
{
g_icmpv6_waiters = notify->nt_flink;
}
ret = OK;
}
leave_critical_section(flags);
(void)nxsem_destroy(&notify->nt_sem);
return ret;
}
/****************************************************************************
* Name: icmpv6_wait
*
* Description:
* Called each time that a Neighbor Solicitation is sent. This function
* will sleep until either: (1) the matching Neighbor Advertisement is
* received, or (2) a timeout occurs.
*
* Assumptions:
* This function is called from icmpv6_neighbor() and must execute with
* the network locked.
*
****************************************************************************/
int icmpv6_wait(FAR struct icmpv6_notify_s *notify,
FAR struct timespec *timeout)
{
struct timespec abstime;
irqstate_t flags;
int ret;
/* And wait for the Neighbor Advertisement (or a timeout). Interrupts will
* be re-enabled while we wait.
*/
flags = enter_critical_section();
DEBUGVERIFY(clock_gettime(CLOCK_REALTIME, &abstime));
abstime.tv_sec += timeout->tv_sec;
abstime.tv_nsec += timeout->tv_nsec;
if (abstime.tv_nsec >= 1000000000)
{
abstime.tv_sec++;
abstime.tv_nsec -= 1000000000;
}
/* REVISIT: If net_timedwait() is awakened with signal, we will return
* the wrong error code.
*/
(void)net_timedwait(&notify->nt_sem, &abstime);
ret = notify->nt_result;
/* Remove our wait structure from the list (we may no longer be at the
* head of the list).
*/
(void)icmpv6_wait_cancel(notify);
/* Re-enable interrupts and return the result of the wait */
leave_critical_section(flags);
return ret;
}
/****************************************************************************
* Name: icmpv6_notify
*
* Description:
* Called each time that a Neighbor Advertisement is received in order to
* wake-up any threads that may be waiting for this particular Neighbor
* Advertisement.
*
* Assumptions:
* This function is called from the MAC device driver indirectly through
* icmpv6_icmpv6in() will execute with the network locked.
*
****************************************************************************/
void icmpv6_notify(net_ipv6addr_t ipaddr)
{
FAR struct icmpv6_notify_s *curr;
/* Find an entry with the matching IP address in the list of waiters */
for (curr = g_icmpv6_waiters; curr; curr = curr->nt_flink)
{
/* Does this entry match? If the result is okay, then we have
* already notified this waiter and it has not yet taken the
* entry from the list.
*/
if (curr->nt_result != OK && net_ipv6addr_cmp(curr->nt_ipaddr, ipaddr))
{
/* Yes.. Signal the waiting, returning success */
curr->nt_result = OK;
nxsem_post(&curr->nt_sem);
break;
}
}
}
#endif /* CONFIG_NET_ICMPv6_NEIGHBOR */