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nuttx/net/igmp/igmp_input.c

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/****************************************************************************
* net/igmp/igmp_input.c
*
* Copyright (C) 2010, 2014, 2020 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 <nuttx/wdog.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"
#include "utils/utils.h"
#ifdef CONFIG_NET_IGMP
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define IPv4BUF ((FAR struct igmp_iphdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev)])
#define IGMPBUF(hl) ((FAR struct igmp_hdr_s *)&dev->d_buf[NET_LL_HDRLEN(dev) + (hl)])
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: igmp_input
*
* Description:
* An IGMP packet has been received.
*
* ________________
* | |
* | |
* | |
* | |
* +--------->| 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) |
* +-------------------+
*
* NOTE: The network must be locked.
*
****************************************************************************/
void igmp_input(struct net_driver_s *dev)
{
FAR struct igmp_iphdr_s *ipv4 = IPv4BUF;
FAR struct igmp_hdr_s *igmp;
FAR struct igmp_group_s *group;
in_addr_t destipaddr;
in_addr_t grpaddr;
uint16_t iphdrlen;
unsigned int ticks;
ninfo("IGMP message: %04x%04x\n", ipv4->destipaddr[1], ipv4->destipaddr[0]);
/* Get the IP header length (accounting for possible options). */
iphdrlen = (ipv4->vhl & IPv4_HLMASK) << 2;
/* The IGMP header immediately follows the IP header */
igmp = IGMPBUF(iphdrlen);
/* Verify the message length */
if (dev->d_len < NET_LL_HDRLEN(dev) + (iphdrlen + IGMP_HDRLEN))
{
IGMP_STATINCR(g_netstats.igmp.length_errors);
nwarn("WARNING: Length error\n");
return;
}
/* Calculate and check the IGMP checksum */
if (net_chksum((FAR uint16_t *)igmp, IGMP_HDRLEN) != 0)
{
IGMP_STATINCR(g_netstats.igmp.chksum_errors);
nwarn("WARNING: Checksum error\n");
return;
}
/* Find the group (or create a new one) using the incoming IP address. */
destipaddr = net_ip4addr_conv32(ipv4->destipaddr);
group = igmp_grpallocfind(dev, &destipaddr);
if (group == NULL)
{
nerr("ERROR: Failed to find/allocate group: %08x\n", destipaddr);
return;
}
/* Now handle the message based on the IGMP message type */
switch (igmp->type)
{
case IGMP_MEMBERSHIP_QUERY:
/* RFC 2236, 2.2. ax Response Time
* "The Max Response Time field is meaningful only in Membership Query
* messages, and specifies the maximum allowed time before sending a
* responding report in units of 1/10 second. In all other messages,
* it is set to zero by the sender and ignored by receivers.
*/
/* Check if the query was sent to all systems */
if (net_ipv4addr_cmp(destipaddr, g_ipv4_allsystems))
{
/* Yes... Now check the if this this is a general or a group
* specific query.
*
* RFC 2236, 2.1. Type
* There are two sub-types of Membership Query messages:
* - General Query, used to learn which groups have members on an
* attached network.
* - Group-Specific Query, used to learn if a particular group
* has any members on an attached network.
*
* RFC 2236, 2.4. Group Address
* "In a Membership Query message, the group address field is
* set to zero when sending a General Query, and set to the
* group address being queried when sending a Group-Specific
* Query."
*/
if (igmp->grpaddr == 0)
{
FAR struct igmp_group_s *member;
/* This is the general query */
ninfo("General multicast query\n");
if (igmp->maxresp == 0)
{
IGMP_STATINCR(g_netstats.igmp.v1_received);
igmp->maxresp = 10;
nwarn("WARNING: V1 not implemented\n");
}
IGMP_STATINCR(g_netstats.igmp.query_received);
for (member = (FAR struct igmp_group_s *)dev->d_igmp_grplist.head;
member;
member = member->next)
{
/* Skip over the all systems group entry */
if (!net_ipv4addr_cmp(member->grpaddr, g_ipv4_allsystems))
{
ticks = net_dsec2tick((int)igmp->maxresp);
if (IS_IDLEMEMBER(member->flags) ||
igmp_cmptimer(member, ticks))
{
igmp_startticks(member, ticks);
CLR_IDLEMEMBER(member->flags);
}
}
}
}
else /* if (igmp->grpaddr != 0) */
{
ninfo("Group-specific multicast query\n");
/* We first need to re-lookup the group since we used dest last time.
* Use the incoming IPaddress!
*/
IGMP_STATINCR(g_netstats.igmp.ucast_query);
grpaddr = net_ip4addr_conv32(igmp->grpaddr);
group = igmp_grpallocfind(dev, &grpaddr);
if (group != NULL)
{
ticks = net_dsec2tick((int)igmp->maxresp);
if (IS_IDLEMEMBER(group->flags) ||
igmp_cmptimer(group, ticks))
{
igmp_startticks(group, ticks);
CLR_IDLEMEMBER(group->flags);
}
}
}
}
/* Not sent to all systems -- Unicast query */
else if (group->grpaddr != 0)
{
ninfo("Unicast query\n");
IGMP_STATINCR(g_netstats.igmp.ucast_query);
ninfo("Query to a specific group with the group address as "
"destination\n");
ticks = net_dsec2tick((int)igmp->maxresp);
if (IS_IDLEMEMBER(group->flags) || igmp_cmptimer(group, ticks))
{
igmp_startticks(group, ticks);
CLR_IDLEMEMBER(group->flags);
}
}
break;
case IGMPv2_MEMBERSHIP_REPORT:
{
ninfo("Membership report\n");
IGMP_STATINCR(g_netstats.igmp.report_received);
if (!IS_IDLEMEMBER(group->flags))
{
/* This is on a specific group we have already looked up */
wd_cancel(group->wdog);
SET_IDLEMEMBER(group->flags);
CLR_LASTREPORT(group->flags);
}
}
break;
default:
{
nwarn("WARNING: Unexpected msg %02x\n", igmp->type);
}
break;
}
dev->d_len = 0;
return;
}
#endif /* CONFIG_NET_IGMP */
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