nuttx/net/igmp/igmp_leave.c
zhanghongyu 43ecf36d78 udp: modify ipv4 multicast to allow different conn to join simultaneously
add ref count for ipv4 multicast and leave the multicast group when close
behavior alignment with linux.

Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>
2023-11-04 17:56:06 +08:00

196 lines
7.5 KiB
C

/****************************************************************************
* net/igmp/igmp_leave.c
*
* Copyright (C) 2010-2011, 2014, 2018 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 <assert.h>
#include <debug.h>
#include <netinet/in.h>
#include <nuttx/wdog.h>
#include <nuttx/net/netconfig.h>
#include <nuttx/net/net.h>
#include <nuttx/net/netstats.h>
#include <nuttx/net/ip.h>
#include <nuttx/net/igmp.h>
#include "devif/devif.h"
#include "igmp/igmp.h"
#ifdef CONFIG_NET_IGMP
/****************************************************************************
* 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:
* The network is locked.
*
****************************************************************************/
int igmp_leavegroup(struct net_driver_s *dev,
FAR const struct in_addr *grpaddr)
{
struct igmp_group_s *group;
int ret;
DEBUGASSERT(dev && grpaddr);
/* Find the entry corresponding to the address leaving the group */
group = igmp_grpfind(dev, &grpaddr->s_addr);
ninfo("Leaving group: %p\n", group);
if (group)
{
DEBUGASSERT(group->njoins > 0);
group->njoins--;
/* Take no further actions if there are other members of this group
* on this host.
*/
if (group->njoins > 0)
{
return OK;
}
/* 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.
*/
wd_cancel(&group->wdog);
CLR_SCHEDMSG(group->flags);
CLR_WAITMSG(group->flags);
IGMP_STATINCR(g_netstats.igmp.leaves);
/* Send a leave if the flag is set according to the state diagram */
if (IS_LASTREPORT(group->flags))
{
ninfo("Schedule Leave Group message\n");
IGMP_STATINCR(g_netstats.igmp.leave_sched);
ret = igmp_waitmsg(group, IGMP_LEAVE_GROUP);
if (ret < 0)
{
nerr("ERROR: Failed to schedule message: %d\n", ret);
}
}
/* Free the group structure (state is now Non-Member */
igmp_grpfree(dev, group);
/* And remove the group address from the drivers MAC filter set */
igmp_removemcastmac(dev, (FAR in_addr_t *)&grpaddr->s_addr);
return OK;
}
/* Return ENOENT if the address is not a member of the group */
ninfo("Return -ENOENT\n");
return -ENOENT;
}
#endif /* CONFIG_NET_IGMP */