/**************************************************************************/ /* */ /* 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 */