/**************************************************************************** * net/icmpv6/icmpv6_notify.c * * Copyright (C) 2015-2016 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include #include #include #include #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. */ 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_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); nxsem_destroy(¬ify->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. */ net_timedwait(¬ify->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). */ 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 */