/****************************************************************************
* net/mld/mld_leave.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* 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/mld.h>
#include "netdev/netdev.h"
#include "mld/mld.h"
#ifdef CONFIG_NET_MLD
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: mld_leavegroup
*
* Description:
* Remove the specified group address to the group. This function
* implements the logic for the IPV6_LEAVE_GROUP socket option.
*
* The IPV6_JOIN_GROUP socket option is used to join a multicast group.
* This is accomplished by using the setsockopt() API and specifying the
* address of the ipv6_mreq structure containing the IPv6 multicast address
* and the local IPv6 multicast interface index. The stack chooses a
* default multicast interface if an interface index of 0 is passed. The
* values specified in the IPV6_MREQ structure used by IPV6_JOIN_GROUP
* and IPV6_LEAVE_GROUP must be symmetrical. The format of the ipv6_mreq
* structure can be found in include/netinet/in.h
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
int mld_leavegroup(FAR const struct ipv6_mreq *mrec)
{
FAR struct net_driver_s *dev;
struct mld_group_s *group;
int ret;
DEBUGASSERT(mrec != NULL);
/* Get the device from the interface index. Use the default network device
* if an interface index of 0 is provided.
*/
if (mrec->ipv6mr_interface == 0)
{
dev = netdev_default();
}
else
{
dev = netdev_findbyindex(mrec->ipv6mr_interface);
}
if (dev == NULL)
{
return -ENODEV;
}
mldinfo("Leave group: %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
NTOHS(mrec->ipv6mr_multiaddr.s6_addr16[0]),
NTOHS(mrec->ipv6mr_multiaddr.s6_addr16[1]),
NTOHS(mrec->ipv6mr_multiaddr.s6_addr16[2]),
NTOHS(mrec->ipv6mr_multiaddr.s6_addr16[3]),
NTOHS(mrec->ipv6mr_multiaddr.s6_addr16[4]),
NTOHS(mrec->ipv6mr_multiaddr.s6_addr16[5]),
NTOHS(mrec->ipv6mr_multiaddr.s6_addr16[6]),
NTOHS(mrec->ipv6mr_multiaddr.s6_addr16[7]));
/* Find the entry corresponding to the address leaving the group */
group = mld_grpfind(dev, mrec->ipv6mr_multiaddr.s6_addr16);
if (group != NULL)
{
mldinfo("Leaving group: %p\n", group);
/* Indicate one fewer members of the group from this host */
DEBUGASSERT(group->njoins > 0);
group->njoins--;
MLD_STATINCR(g_netstats.mld.nleaves);
/* Take no further actions if there are other members of this group
* on this host.
*/
if (group->njoins > 0)
{
return OK;
}
/* Perform actions that would be performed only when the number of
* njoins from this host goes to zero.
*/
if (group->njoins == 0)
{
/* Send a leave if the LASTREPORT flag is set for the group. If
* there are other members of the group, then their reports will
* clear the LAST REPORT flag. In this case we know that there are
* other members of the group and we do not have to send the Done
* message.
*
* The MLDv1 router responds to the Done message with a multicast-
* address- specific (MAS) Query. If any other node responds to
* the Query with a Report message the there are still listeners
* present.
*/
if (IS_MLD_LASTREPORT(group->flags))
{
mldinfo("Schedule Done message\n");
MLD_STATINCR(g_netstats.mld.done_sched);
/* REVISIT: This will interfere if there are any other tasks
* waiting for a message to be sent. Can that happen?
*/
ret = mld_waitmsg(group, MLD_SEND_DONE);
if (ret < 0)
{
mlderr("ERROR: Failed to schedule message: %d\n", ret);
}
}
/* Remove the group address from the Ethernet drivers MAC filter
* set
*/
mld_removemcastmac(dev, mrec->ipv6mr_multiaddr.s6_addr16);
/* Perform additional the number of members not on this host is
* also zero.
*/
#ifdef CONFIG_NET_MLD_ROUTER
if (group->members == 0 && group->lstmbrs == 0)
#endif
{
/* Cancel the timers and discard any queued Reports. Canceling
* the timer will prevent any new Reports from being sent;
* clearing the flags will discard any pending Reports that
* could interfere with freeing the group.
*/
wd_cancel(&group->polldog);
CLR_MLD_SCHEDMSG(group->flags);
CLR_MLD_WAITMSG(group->flags);
/* Free the group structure */
mld_grpfree(dev, group);
/* REVISIT: It is expected that higher level logic will remove
* the routing table entry for the old multicast address. That
* is not done here.
*/
}
}
return OK;
}
/* Return ENOENT if the address is not a member of the group */
mldinfo("Return -ENOENT\n");
return -ENOENT;
}
#endif /* CONFIG_NET_MLD */