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Diffstat (limited to 'nuttx/net/uip/uip_igmpleave.c')
| -rwxr-xr-x | nuttx/net/uip/uip_igmpleave.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/nuttx/net/uip/uip_igmpleave.c b/nuttx/net/uip/uip_igmpleave.c new file mode 100755 index 000000000..7e2a31a19 --- /dev/null +++ b/nuttx/net/uip/uip_igmpleave.c @@ -0,0 +1,182 @@ +/**************************************************************************** + * net/uip/uip_igmpleave.c + * + * Copyright (C) 2010-2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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 <nuttx/config.h> + +#include <wdog.h> +#include <assert.h> +#include <debug.h> + +#include <nuttx/net/uip/uipopt.h> +#include <nuttx/net/uip/uip.h> +#include <nuttx/net/uip/uip-igmp.h> + +#include "uip_internal.h" + +#ifdef CONFIG_NET_IGMP + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: igmp_leavegroup + * + * Description: + * Remove the specified group address to the group. + * + * RFC 2236, 3. Protocol Description: + * + * "When a host leaves a multicast group, if it was the last host to + * reply to a Query with a Membership Report for that group, it SHOULD + * send a Leave Group message to the all-routers multicast group + * (224.0.0.2). If it was not the last host to reply to a Query, it MAY + * send nothing as there must be another member on the subnet. This is + * an optimization to reduce traffic; a host without sufficient storage + * to remember whether or not it was the last host to reply MAY always + * send a Leave Group message when it leaves a group. Routers SHOULD + * accept a Leave Group message addressed to the group being left, in + * order to accommodate implementations of an earlier version of this + * standard. Leave Group messages are addressed to the all-routers + * group because other group members have no need to know that a host + * has left the group, but it does no harm to address the message to the + * group." + * + * ________________ + * | | + * | | + * | | + * | | + * +--------->| Non-Member |<---------+ + * | | | | + * | | | | + * | | | | + * | |________________| | + * | | | + * | leave group | join group | leave group + * | (stop timer, |(send report, | (send leave + * | send leave if | set flag, | if flag set) + * | flag set) | start timer) | + * ________|________ | ________|________ + * | |<---------+ | | + * | | | | + * | |<-------------------| | + * | | query received | | + * | Delaying Member | (start timer) | Idle Member | + * +---->| |------------------->| | + * | | | report received | | + * | | | (stop timer, | | + * | | | clear flag) | | + * | |_________________|------------------->|_________________| + * | query received | timer expired + * | (reset timer if | (send report, + * | Max Resp Time | set flag) + * | < current timer) | + * +-------------------+ + * + * Assumptions: + * This function cannot be called from interrupt handling logic! + * + ****************************************************************************/ + +int igmp_leavegroup(struct uip_driver_s *dev, FAR const struct in_addr *grpaddr) +{ + struct igmp_group_s *group; + uip_lock_t flags; + + DEBUGASSERT(dev && grpaddr); + + /* Find the entry corresponding to the address leaving the group */ + + group = uip_grpfind(dev, &grpaddr->s_addr); + ndbg("Leaving group: %p\n", group); + if (group) + { + /* Cancel the timer and discard any queued Membership Reports. Canceling + * the timer will prevent any new Membership Reports from being sent; + * clearing the flags will discard any pending Membership Reports that + * could interfere with the Leave Group. + */ + + flags = uip_lock(); + wd_cancel(group->wdog); + CLR_SCHEDMSG(group->flags); + CLR_WAITMSG(group->flags); + uip_unlock(flags); + + IGMP_STATINCR(uip_stat.igmp.leaves); + + /* Send a leave if the flag is set according to the state diagram */ + + if (IS_LASTREPORT(group->flags)) + { + ndbg("Schedule Leave Group message\n"); + IGMP_STATINCR(uip_stat.igmp.leave_sched); + uip_igmpwaitmsg(group, IGMP_LEAVE_GROUP); + } + + /* Free the group structure (state is now Non-Member */ + + uip_grpfree(dev, group); + + /* And remove the group address from the ethernet drivers MAC filter set */ + + uip_removemcastmac(dev, (FAR uip_ipaddr_t *)&grpaddr->s_addr); + return OK; + } + + /* Return ENOENT if the address is not a member of the group */ + + nvdbg("Return -ENOENT\n"); + return -ENOENT; +} + +#endif /* CONFIG_NET_IGMP */ |