/**************************************************************************** * net/igmp/igmp_timer.c * * Copyright (C) 2010-2011 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * The NuttX implementation of IGMP was inspired by the IGMP add-on for the * lwIP TCP/IP stack by Steve Reynolds: * * Copyright (c) 2002 CITEL Technologies Ltd. * All rights reserved. * * 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 "devif/devif.h" #include "igmp/igmp.h" #ifdef CONFIG_NET_IGMP /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Debug ********************************************************************/ #undef IGMP_GTMRDEBUG /* Define to enable detailed IGMP group debug */ #ifndef CONFIG_NET_IGMP # undef IGMP_GTMRDEBUG #endif #ifdef CONFIG_CPP_HAVE_VARARGS # ifdef IGMP_GTMRDEBUG # define gtmrdbg(format, ...) ndbg(format, ##__VA_ARGS__) # define gtmrlldbg(format, ...) nlldbg(format, ##__VA_ARGS__) # define gtmrvdbg(format, ...) nvdbg(format, ##__VA_ARGS__) # define gtmrllvdbg(format, ...) nllvdbg(format, ##__VA_ARGS__) # else # define gtmrdbg(x...) # define gtmrlldbg(x...) # define gtmrvdbg(x...) # define gtmrllvdbg(x...) # endif #else # ifdef IGMP_GTMRDEBUG # define gtmrdbg ndbg # define gtmrlldbg nlldbg # define gtmrvdbg nvdbg # define gtmrllvdbg nllvdbg # else # define gtmrdbg (void) # define gtmrlldbg (void) # define gtmrvdbg (void) # define gtmrllvdbg (void) # endif #endif /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: igmp_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 igmp_timeout(int argc, uint32_t arg, ...) { FAR struct igmp_group_s *group; /* If the state is DELAYING_MEMBER then we send a report for this group */ nllvdbg("Timeout!\n"); group = (FAR struct igmp_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 IGMPv2_MEMBERSHIP_REPORT during the join, and (2) * the timer is cancelled before sending the IGMP_LEAVE_GROUP during a leave. */ if (!IS_IDLEMEMBER(group->flags)) { /* Schedule (and forget) the Membership Report. NOTE: * Since we are executing from a timer interrupt, we cannot wait * for the message to be sent. */ IGMP_STATINCR(g_netstats.igmp.report_sched); igmp_schedmsg(group, IGMPv2_MEMBERSHIP_REPORT); /* Also note: The Membership Report is sent at most two times becasue * 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 Membership * Report being lost or damaged, it is recommended that it be repeated * once or twice after short delays [Unsolicited Report Interval]..." */ } } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: igmp_decisec2tick * * Description: * Convert the deci-second value to units of system clock ticks. * * Assumptions: * This function may be called from most any context. * ****************************************************************************/ int igmp_decisec2tick(int decisecs) { /* Convert the deci-second comparison value to clock ticks. The CLK_TCK * value is the number of clock ticks per second; decisecs argument is the * maximum delay in 100's of milliseconds. CLK_TCK/10 is then the number * of clock ticks in 100 milliseconds. */ return CLK_TCK * decisecs / 10; } /**************************************************************************** * Name: igmp_startticks and igmp_starttimer * * Description: * Start the IGMP timer with differing time units (ticks or deciseconds). * * Assumptions: * This function may be called from most any context. * ****************************************************************************/ void igmp_startticks(FAR struct igmp_group_s *group, int ticks) { int ret; /* Start the timer */ gtmrlldbg("ticks: %d\n", ticks); ret = wd_start(group->wdog, ticks, igmp_timeout, 1, (uint32_t)group); DEBUGASSERT(ret == OK); UNUSED(ret); } void igmp_starttimer(FAR struct igmp_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 */ gtmrdbg("decisecs: %d\n", decisecs); igmp_startticks(group, igmp_decisec2tick(decisecs)); } /**************************************************************************** * Name: igmp_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 igmp_startticks() to restart the timer * ****************************************************************************/ bool igmp_cmptimer(FAR struct igmp_group_s *group, int maxticks) { net_lock_t flags; int remaining; /* Disable interrupts so that there is no race condition with the actual * timer expiration. */ flags = net_lock(); /* 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. */ gtmrdbg("maxticks: %d remaining: %d\n", maxticks, remaining); if (maxticks > remaining) { /* Cancel the watchdog timer and return true */ wd_cancel(group->wdog); net_unlock(flags); return true; } net_unlock(flags); return false; } #endif /* CONFIG_NET_IGMP */