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- /****************************************************************************
- * net/arp/arp_notify.c
- *
- * Copyright (C) 2014, 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 <time.h>
- #include <semaphore.h>
- #include <errno.h>
- #include <assert.h>
- #include <debug.h>
- #include <netinet/in.h>
- #include <nuttx/irq.h>
- #include <nuttx/semaphore.h>
- #include <nuttx/net/net.h>
- #include "arp/arp.h"
- #ifdef CONFIG_NET_ARP_SEND
- /****************************************************************************
- * Private Data
- ****************************************************************************/
- /* List of tasks waiting for ARP events */
- static FAR struct arp_notify_s *g_arp_waiters;
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: arp_wait_setup
- *
- * Description:
- * Called BEFORE an ARP request is sent. This function sets up the ARP
- * response timeout before the ARP request is sent so that there is
- * no race condition when arp_wait() is called.
- *
- * Assumptions:
- * This function is called from ARP send and executes in the normal
- * tasking environment.
- *
- ****************************************************************************/
- void arp_wait_setup(in_addr_t ipaddr, FAR struct arp_notify_s *notify)
- {
- irqstate_t flags;
- /* Initialize the wait structure */
- 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(¬ify->nt_sem, 0, 0);
- nxsem_setprotocol(¬ify->nt_sem, SEM_PRIO_NONE);
- /* Add the wait structure to the list with interrupts disabled */
- flags = enter_critical_section();
- notify->nt_flink = g_arp_waiters;
- g_arp_waiters = notify;
- leave_critical_section(flags);
- }
- /****************************************************************************
- * Name: arp_wait_cancel
- *
- * Description:
- * Cancel any wait set after arp_wait_setup is called but before arp_wait()
- * is called (arp_wait() will automatically cancel the wait).
- *
- * Assumptions:
- * This function may execute with interrupts disabled when called from
- * arp_wait().
- *
- ****************************************************************************/
- int arp_wait_cancel(FAR struct arp_notify_s *notify)
- {
- FAR struct arp_notify_s *curr;
- FAR struct arp_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_arp_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_arp_waiters = notify->nt_flink;
- }
- ret = OK;
- }
- leave_critical_section(flags);
- (void)nxsem_destroy(¬ify->nt_sem);
- return ret;
- }
- /****************************************************************************
- * Name: arp_wait
- *
- * Description:
- * Called each time that a ARP request is sent. This function will sleep
- * until either: (1) the matching ARP response is received, or (2) a
- * timeout occurs.
- *
- * Assumptions:
- * This function is called from ARP send must execute with the network
- * locked.
- *
- ****************************************************************************/
- int arp_wait(FAR struct arp_notify_s *notify, FAR struct timespec *timeout)
- {
- struct timespec abstime;
- irqstate_t flags;
- int errcode;
- int ret;
- /* And wait for the ARP response (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;
- }
- /* Wait to get either the correct response or a timeout. */
- do
- {
- /* The only errors that we expect would be if the abstime timeout
- * expires or if the wait were interrupted by a signal.
- */
- ret = net_timedwait(¬ify->nt_sem, &abstime);
- errcode = ((ret < 0) ? -ret : 0);
- }
- while (ret < 0 && errcode == EINTR);
- /* Then get the real result of the transfer */
- ret = notify->nt_result;
- /* Remove our wait structure from the list (we may no longer be at the
- * head of the list).
- */
- (void)arp_wait_cancel(notify);
- /* Re-enable interrupts and return the result of the wait */
- leave_critical_section(flags);
- return ret;
- }
- /****************************************************************************
- * Name: arp_notify
- *
- * Description:
- * Called each time that a ARP response is received in order to wake-up
- * any threads that may be waiting for this particular ARP response.
- *
- * Assumptions:
- * This function is called from the MAC device driver indirectly through
- * arp_arpin() will execute with the network locked.
- *
- ****************************************************************************/
- void arp_notify(in_addr_t ipaddr)
- {
- FAR struct arp_notify_s *curr;
- /* Find an entry with the matching IP address in the list of waiters */
- for (curr = g_arp_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 && curr->nt_ipaddr == ipaddr)
- {
- /* Yes.. Signal the waiting, returning success */
- curr->nt_result = OK;
- nxsem_post(&curr->nt_sem);
- break;
- }
- }
- }
- #endif /* CONFIG_NET_ARP_SEND */
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