/**************************************************************************** * net/mld/mld_leave.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 "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", mrec->ipv6mr_multiaddr.s6_addr16[0], mrec->ipv6mr_multiaddr.s6_addr16[1], mrec->ipv6mr_multiaddr.s6_addr16[2], mrec->ipv6mr_multiaddr.s6_addr16[3], mrec->ipv6mr_multiaddr.s6_addr16[4], mrec->ipv6mr_multiaddr.s6_addr16[5], mrec->ipv6mr_multiaddr.s6_addr16[5], 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); /* REVIST: This will interfere is the 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 */