/****************************************************************************
* net/igmp/igmp_join.c
*
* Copyright (C) 2010 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/net/netconfig.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
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: igmp_joingroup
*
* Description:
* Add the specified group address to the group.
*
* RFC 2236, 3. Protocol Description:
*
* "When a host joins a multicast group, it should immediately transmit
* an unsolicited Version 2 Membership Report for that group, in case it
* is the first member of that group on the network. 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]. (A simple way to accomplish
* this is to send the initial Version 2 Membership Report and then act
* as if a Group-Specific Query was received for that group, and set a
* timer appropriately)."
* ________________
* | |
* | |
* | |
* | |
* +--------->| 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_joingroup(struct net_driver_s *dev, FAR const struct in_addr *grpaddr)
{
struct igmp_group_s *group;
DEBUGASSERT(dev && grpaddr);
/* Check if a this address is already in the group */
group = igmp_grpfind(dev, &grpaddr->s_addr);
if (!group)
{
/* No... allocate a new entry */
nvdbg("Join to new group: %08x\n", grpaddr->s_addr);
group = igmp_grpalloc(dev, &grpaddr->s_addr);
IGMP_STATINCR(g_netstats.igmp.joins);
/* Send the Membership Report */
IGMP_STATINCR(g_netstats.igmp.report_sched);
igmp_waitmsg(group, IGMPv2_MEMBERSHIP_REPORT);
/* And start the timer at 10*100 msec */
igmp_starttimer(group, 10);
/* Add the group (MAC) address to the ether drivers MAC filter list */
igmp_addmcastmac(dev, (FAR in_addr_t *)&grpaddr->s_addr);
return OK;
}
/* Return EEXIST if the address is already a member of the group */
return -EEXIST;
}
#endif /* CONFIG_NET_IGMP */
