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/**************************************************************************/
/* */
/* Copyright (c) Microsoft Corporation. All rights reserved. */
/* */
/* This software is licensed under the Microsoft Software License */
/* Terms for Microsoft Azure RTOS. Full text of the license can be */
/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
/* and in the root directory of this software. */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** NetX Component */
/** */
/** Internet Group Management Protocol (IGMP) */
/** */
/**************************************************************************/
/**************************************************************************/
#define NX_SOURCE_CODE
/* Include necessary system files. */
#include "nx_api.h"
#include "nx_igmp.h"
#include "nx_ipv4.h"
#include "nx_packet.h"
#ifndef NX_DISABLE_IPV4
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_igmp_interface_report_send PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* Yuxin Zhou, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function builds and sends an IGMP report. If it is a JOIN */
/* report, the IP nx_igmp_reports_sent statistic is incremented. */
/* */
/* Note: An IGMPv1 host does not send a LEAVE message. The caller in */
/* that case, _nx_igmp_multicast_interface_leave_internal, checks the */
/* IGMP host version and only calls this function for IGMPv2 hosts. */
/* */
/* INPUT */
/* */
/* ip_ptr IP instance pointer */
/* group_address Multicast group to join */
/* interface_index Index to the interface */
/* is_joining Indicate if joining or leaving*/
/* NX_TRUE = send join report */
/* NX_FALSE = send leave report*/
/* */
/* OUTPUT */
/* */
/* status Completion status */
/* */
/* CALLS */
/* */
/* _nx_ip_packet_send Send packet from the IP layer */
/* _nx_packet_allocate Allocate a packet for report */
/* tx_mutex_get Obtain protection mutex */
/* tx_mutex_put Release protection mutex */
/* */
/* CALLED BY */
/* */
/* nx_igmp_periodic_processing Performs periodic IGMP tasks */
/* nx_igmp_multicast_interface_leave_internal */
/* Processes a LEAVE report for */
/* transmission to all routers */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 05-19-2020 Yuxin Zhou Initial Version 6.0 */
/* 09-30-2020 Yuxin Zhou Modified comment(s), */
/* resulting in version 6.1 */
/* */
/**************************************************************************/
UINT _nx_igmp_interface_report_send(NX_IP *ip_ptr, ULONG group_address, UINT interface_index, UINT is_joining)
{
NX_INTERFACE *nx_interface;
UINT router_alert = 0;
UINT status;
ULONG checksum;
ULONG temp;
NX_PACKET *packet_ptr;
NX_IGMP_HEADER *header_ptr;
#ifndef NX_DISABLE_IGMPV2
if (ip_ptr -> nx_ip_igmp_router_version == NX_IGMP_HOST_VERSION_2)
{
router_alert = 4;
}
#endif
/* Obtain the IP mutex so we can search the multicast join list. */
tx_mutex_get(&(ip_ptr -> nx_ip_protection), TX_WAIT_FOREVER);
nx_interface = &ip_ptr -> nx_ip_interface[interface_index];
/* Build an IGMP host response packet and send it! */
/* Allocate a packet to place the IGMP host response message in. */
#ifdef NX_ENABLE_DUAL_PACKET_POOL
/* Allocate from auxiliary packet pool first. */
status = _nx_packet_allocate(ip_ptr -> nx_ip_auxiliary_packet_pool, &packet_ptr, (ULONG)(NX_IGMP_PACKET + router_alert + NX_IGMP_HEADER_SIZE), TX_NO_WAIT);
if ((status != NX_SUCCESS) && (ip_ptr -> nx_ip_auxiliary_packet_pool != ip_ptr -> nx_ip_default_packet_pool))
#endif /* NX_ENABLE_DUAL_PACKET_POOL */
{
status = _nx_packet_allocate(ip_ptr -> nx_ip_default_packet_pool, &packet_ptr, (ULONG)(NX_IGMP_PACKET + router_alert + NX_IGMP_HEADER_SIZE), TX_NO_WAIT);
}
if (status)
{
/* Packet allocation failed. Release the mutex and return error status. */
tx_mutex_put(&(ip_ptr -> nx_ip_protection));
return(status);
}
/* Add debug information. */
NX_PACKET_DEBUG(__FILE__, __LINE__, packet_ptr);
/* Prepare an IGMP response and send on the "all hosts" multicast
address. */
#ifndef NX_DISABLE_IGMP_INFO
/* Increase the IGMP reports sent count. */
if (is_joining == NX_TRUE)
{
ip_ptr -> nx_ip_igmp_reports_sent++;
}
#endif
/* Calculate the IGMP response message size and store it in the
packet header. */
/*lint -e{644} suppress variable might not be initialized, since "packet_ptr" was initialized as long as status is NX_SUCCESS. */
packet_ptr -> nx_packet_length = NX_IGMP_HEADER_SIZE;
/* Setup the prepend pointer. */
packet_ptr -> nx_packet_prepend_ptr -= NX_IGMP_HEADER_SIZE;
/* Stamp the outgoing interface. */
packet_ptr -> nx_packet_address.nx_packet_interface_ptr = nx_interface;
/* Build the IGMP host response packet. */
/* Setup the pointer to the message area. */
/*lint -e{927} -e{826} suppress cast of pointer to pointer, since it is necessary */
header_ptr = (NX_IGMP_HEADER *)packet_ptr -> nx_packet_prepend_ptr;
#ifndef NX_DISABLE_IGMPV2
/* Build the IGMPv2 response message. */
/* Is the router using IGMPv1? */
if (ip_ptr -> nx_ip_igmp_router_version == NX_IGMP_HOST_VERSION_1)
{
#endif /* NX_DISABLE_IGMPV2 */
/* Yes; Set the header fields with the max response time
zero and the version/type 0x12. */
header_ptr -> nx_igmp_header_word_0 = (ULONG)(NX_IGMP_VERSION | NX_IGMP_HOST_RESPONSE_TYPE);
header_ptr -> nx_igmp_header_word_1 = group_address;
#ifndef NX_DISABLE_IGMPV2
}
/* The router is running the IGMPv2 (or higher) protocol. */
else
{
/* Indicate if the report is a join or leave report. */
if (is_joining)
{
header_ptr -> nx_igmp_header_word_0 = (ULONG)(NX_IGMP_HOST_V2_JOIN_TYPE);
}
else
{
header_ptr -> nx_igmp_header_word_0 = (ULONG)(NX_IGMP_HOST_V2_LEAVE_TYPE);
}
header_ptr -> nx_igmp_header_word_1 = group_address;
}
#endif /* NX_DISABLE_IGMPV2 */
#ifdef NX_ENABLE_INTERFACE_CAPABILITY
if (!(packet_ptr -> nx_packet_address.nx_packet_interface_ptr -> nx_interface_capability_flag & NX_INTERFACE_CAPABILITY_IGMP_TX_CHECKSUM))
#endif /* NX_ENABLE_INTERFACE_CAPABILITY */
{
/* Calculate the checksum. */
temp = header_ptr -> nx_igmp_header_word_0;
checksum = (temp >> NX_SHIFT_BY_16);
checksum += (temp & NX_LOWER_16_MASK);
temp = header_ptr -> nx_igmp_header_word_1;
checksum += (temp >> NX_SHIFT_BY_16);
checksum += (temp & NX_LOWER_16_MASK);
/* Add in the carry bits into the checksum. */
checksum = (checksum >> NX_SHIFT_BY_16) + (checksum & NX_LOWER_16_MASK);
/* Do it again in case previous operation generates an overflow. */
checksum = (checksum >> NX_SHIFT_BY_16) + (checksum & NX_LOWER_16_MASK);
/* Place the checksum into the first header word. */
header_ptr -> nx_igmp_header_word_0 = header_ptr -> nx_igmp_header_word_0 | (~checksum & NX_LOWER_16_MASK);
}
#ifdef NX_ENABLE_INTERFACE_CAPABILITY
else
{
packet_ptr -> nx_packet_interface_capability_flag |= NX_INTERFACE_CAPABILITY_IGMP_TX_CHECKSUM;
}
#endif /* NX_ENABLE_INTERFACE_CAPABILITY */
/* IGMPv2 packets must be IPv4 packets. */
packet_ptr -> nx_packet_ip_version = NX_IP_VERSION_V4;
/* If NX_LITTLE_ENDIAN is defined, the headers need to be swapped. */
NX_CHANGE_ULONG_ENDIAN(header_ptr -> nx_igmp_header_word_0);
NX_CHANGE_ULONG_ENDIAN(header_ptr -> nx_igmp_header_word_1);
/* Send the IGMP response packet out! */
if (is_joining == NX_TRUE)
{
/* For JOIN reports, set the packet destination to the group address. */
_nx_ip_packet_send(ip_ptr, packet_ptr,
group_address,
NX_IP_NORMAL, NX_IGMP_TTL, NX_IP_IGMP, NX_FRAGMENT_OKAY,
group_address);
}
else
{
/* For LEAVE reports, set the destination to ALL ROUTERS as per RFC 2236 Section 3 page 4.*/
_nx_ip_packet_send(ip_ptr, packet_ptr,
NX_ALL_ROUTERS_ADDRESS,
NX_IP_NORMAL, NX_IGMP_TTL, NX_IP_IGMP, NX_FRAGMENT_OKAY,
NX_ALL_ROUTERS_ADDRESS);
}
/* Release the protection over the IP instance. */
tx_mutex_put(&(ip_ptr -> nx_ip_protection));
return NX_SUCCESS;
}
#endif /* NX_DISABLE_IPV4 */