/**************************************************************************** * net/mld/mld_timer.c * * Copyright (C) 2018 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 of CITEL Technologies Ltd 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 CITEL TECHNOLOGIES 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 CITEL TECHNOLOGIES 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 "devif/devif.h" #include "mld/mld.h" #include "utils/utils.h" #ifdef CONFIG_NET_MLD /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Debug ********************************************************************/ #undef MLD_GTMRDEBUG /* Define to enable detailed MLD group debug */ #ifndef CONFIG_NET_MLD # undef MLD_GTMRDEBUG #endif #ifdef CONFIG_CPP_HAVE_VARARGS # ifdef MLD_GTMRDEBUG # define gtmrerr(format, ...) nerr(format, ##__VA_ARGS__) # define gtmrinfo(format, ...) ninfo(format, ##__VA_ARGS__) # else # define gtmrerr(x...) # define gtmrinfo(x...) # endif #else # ifdef MLD_GTMRDEBUG # define gtmrerr nerr # define gtmrinfo ninfo # else # define gtmrerr (void) # define gtmrinfo (void) # endif #endif /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: mld_timeout * * Description: * Timeout watchdog handler. * * Assumptions: * This function is called from the wdog timer handler which runs in the * context of the timer interrupt handler. * ****************************************************************************/ static void mld_timeout(int argc, uint32_t arg, ...) { FAR struct mld_group_s *group; /* If the state is DELAYING_MEMBER then we send a report for this group */ ninfo("Timeout!\n"); group = (FAR struct mld_group_s *)arg; DEBUGASSERT(argc == 1 && group); /* If the group exists and is no an IDLE MEMBER, then it must be a DELAYING * member. Race conditions are avoided because (1) the timer is not started * until after the first MLDv2_MEMBERSHIP_REPORT during the join, and (2) * the timer is canceled before sending the ICMPV6_MCAST_LISTEN_DONE_V1 * during a leave. */ if (!IS_MLD_IDLEMEMBER(group->flags)) { /* Schedule (and forget) the Report. NOTE: Since we are executing * from a timer interrupt, we cannot wait for the message to be sent. */ MLD_STATINCR(g_netstats.mld.report_sched); mld_schedmsg(group, ICMPV6_MCAST_LISTEN_REPORT_V1); /* Also note: The Report is sent at most two times because the timer * is not reset here. Hmm.. does this mean that the group is stranded * if both reports were lost? This is consistent with the * RFC that states: "To cover the possibility of the initial Report * being lost or damaged, it is recommended that it be repeated once * or twice after short delays [Unsolicited Report Interval]...." * (RFC 2710). */ } } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: mld_startticks and mld_starttimer * * Description: * Start the MLD timer with differing time units (ticks or deciseconds). * * Assumptions: * This function may be called from most any context. * ****************************************************************************/ void mld_startticks(FAR struct mld_group_s *group, unsigned int ticks) { int ret; /* Start the timer */ gtmrinfo("ticks: %d\n", ticks); ret = wd_start(group->wdog, ticks, mld_timeout, 1, (uint32_t)group); DEBUGASSERT(ret == OK); UNUSED(ret); } void mld_starttimer(FAR struct mld_group_s *group, uint8_t decisecs) { /* Convert the decisec value to system clock ticks and start the timer. * Important!! this should be a random timer from 0 to decisecs */ gtmrinfo("decisecs: %d\n", decisecs); mld_startticks(group, net_dsec2tick(decisecs)); } /**************************************************************************** * Name: mld_cmptimer * * Description: * Compare the timer remaining on the watching timer to the deci-second * value. If maxticks > ticks-remaining, then (1) cancel the timer (to * avoid race conditions) and return true. * * Assumptions: * This function may be called from most any context. If true is returned * then the caller must call mld_startticks() to restart the timer * ****************************************************************************/ bool mld_cmptimer(FAR struct mld_group_s *group, int maxticks) { irqstate_t flags; int remaining; /* Disable interrupts so that there is no race condition with the actual * timer expiration. */ flags = enter_critical_section(); /* Get the timer remaining on the watchdog. A time of <= zero means that * the watchdog was never started. */ remaining = wd_gettime(group->wdog); /* A remaining time of zero means that the watchdog was never started * or has already expired. That case should be covered in the following * test as well. */ gtmrinfo("maxticks: %d remaining: %d\n", maxticks, remaining); if (maxticks > remaining) { /* Cancel the watchdog timer and return true */ wd_cancel(group->wdog); leave_critical_section(flags); return true; } leave_critical_section(flags); return false; } #endif /* CONFIG_NET_MLD */