Sergey Pastor
Webserver+3d print
Diff: cyclone_tcp/ipv4/igmp.c
- Revision:
- 0:8918a71cdbe9
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/cyclone_tcp/ipv4/igmp.c Sat Feb 04 18:15:49 2017 +0000
@@ -0,0 +1,633 @@
+/**
+ * @file igmp.c
+ * @brief IGMP (Internet Group Management Protocol)
+ *
+ * @section License
+ *
+ * Copyright (C) 2010-2017 Oryx Embedded SARL. All rights reserved.
+ *
+ * This file is part of CycloneTCP Open.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * @section Description
+ *
+ * IGMP is used by IP hosts to report their multicast group memberships
+ * to routers. Refer to the following RFCs for complete details:
+ * - RFC 1112: Host Extensions for IP Multicasting
+ * - RFC 2236: Internet Group Management Protocol, Version 2
+ * - RFC 3376: Internet Group Management Protocol, Version 3
+ *
+ * @author Oryx Embedded SARL (www.oryx-embedded.com)
+ * @version 1.7.6
+ **/
+
+//Switch to the appropriate trace level
+#define TRACE_LEVEL IGMP_TRACE_LEVEL
+
+//Dependencies
+#include "core/net.h"
+#include "core/ip.h"
+#include "ipv4/ipv4.h"
+#include "ipv4/igmp.h"
+#include "debug.h"
+
+//Check TCP/IP stack configuration
+#if (IPV4_SUPPORT == ENABLED && IGMP_SUPPORT == ENABLED)
+
+//Tick counter to handle periodic operations
+systime_t igmpTickCounter;
+
+
+/**
+ * @brief IGMP initialization
+ * @param[in] interface Underlying network interface
+ * @return Error code
+ **/
+
+error_t igmpInit(NetInterface *interface)
+{
+ //The default host compatibility mode is IGMPv2
+ interface->igmpv1RouterPresent = FALSE;
+
+ //Start IGMPv1 router present timer
+ interface->igmpv1RouterPresentTimer =
+ osGetSystemTime() + IGMP_V1_ROUTER_PRESENT_TIMEOUT;
+
+ //Successful initialization
+ return NO_ERROR;
+}
+
+
+/**
+ * @brief Join the specified host group
+ * @param[in] interface Underlying network interface
+ * @param[in] entry IPv4 filter entry identifying the host group to join
+ * @return Error code
+ **/
+
+error_t igmpJoinGroup(NetInterface *interface, Ipv4FilterEntry *entry)
+{
+ //The all-systems group (address 224.0.0.1) is handled as a special
+ //case. The host starts in Idle Member state for that group on every
+ //interface and never transitions to another state
+ if(entry->addr == IGMP_ALL_SYSTEMS_ADDR)
+ {
+ //Clear flag
+ entry->flag = FALSE;
+ //Enter the Idle Member state
+ entry->state = IGMP_STATE_IDLE_MEMBER;
+ }
+ else
+ {
+ //Link is up?
+ if(interface->linkState)
+ {
+ //When a host joins a multicast group, it should immediately transmit
+ //an unsolicited Membership Report for that group
+ igmpSendReportMessage(interface, entry->addr);
+
+ //Set flag
+ entry->flag = TRUE;
+ //Start timer
+ entry->timer = osGetSystemTime() + IGMP_UNSOLICITED_REPORT_INTERVAL;
+ //Enter the Delaying Member state
+ entry->state = IGMP_STATE_DELAYING_MEMBER;
+ }
+ //Link is down?
+ else
+ {
+ //Clear flag
+ entry->flag = FALSE;
+ //Enter the Idle Member state
+ entry->state = IGMP_STATE_IDLE_MEMBER;
+ }
+ }
+
+ //Successful processing
+ return NO_ERROR;
+}
+
+
+/**
+ * @brief Leave the specified host group
+ * @param[in] interface Underlying network interface
+ * @param[in] entry IPv4 filter entry identifying the host group to leave
+ * @return Error code
+ **/
+
+error_t igmpLeaveGroup(NetInterface *interface, Ipv4FilterEntry *entry)
+{
+ //Check link state
+ if(interface->linkState)
+ {
+ //Send a Leave Group message if the flag is set
+ if(entry->flag)
+ igmpSendLeaveGroupMessage(interface, entry->addr);
+ }
+
+ //Switch to the Non-Member state
+ entry->state = IGMP_STATE_NON_MEMBER;
+
+ //Successful processing
+ return NO_ERROR;
+}
+
+
+/**
+ * @brief IGMP timer handler
+ *
+ * This routine must be periodically called by the TCP/IP stack to
+ * handle IGMP related timers
+ *
+ * @param[in] interface Underlying network interface
+ **/
+
+void igmpTick(NetInterface *interface)
+{
+ uint_t i;
+ systime_t time;
+ Ipv4FilterEntry *entry;
+
+ //Get current time
+ time = osGetSystemTime();
+
+ //Check IGMPv1 router present timer
+ if(timeCompare(time, interface->igmpv1RouterPresentTimer) >= 0)
+ interface->igmpv1RouterPresent = FALSE;
+
+ //Go through the multicast filter table
+ for(i = 0; i < IPV4_MULTICAST_FILTER_SIZE; i++)
+ {
+ //Point to the current entry
+ entry = &interface->ipv4Context.multicastFilter[i];
+
+ //Valid entry?
+ if(entry->refCount > 0)
+ {
+ //Delaying Member state?
+ if(entry->state == IGMP_STATE_DELAYING_MEMBER)
+ {
+ //Timer expired?
+ if(timeCompare(time, entry->timer) >= 0)
+ {
+ //Send a Membership Report message for the group on the interface
+ igmpSendReportMessage(interface, entry->addr);
+
+ //Set flag
+ entry->flag = TRUE;
+ //Switch to the Idle Member state
+ entry->state = IGMP_STATE_IDLE_MEMBER;
+ }
+ }
+ }
+ }
+}
+
+
+/**
+ * @brief Callback function for link change event
+ * @param[in] interface Underlying network interface
+ **/
+
+void igmpLinkChangeEvent(NetInterface *interface)
+{
+ uint_t i;
+ systime_t time;
+ Ipv4FilterEntry *entry;
+
+ //Get current time
+ time = osGetSystemTime();
+
+ //Link up event?
+ if(interface->linkState)
+ {
+ //The default host compatibility mode is IGMPv2
+ interface->igmpv1RouterPresent = FALSE;
+ //Start IGMPv1 router present timer
+ interface->igmpv1RouterPresentTimer = time + IGMP_V1_ROUTER_PRESENT_TIMEOUT;
+
+ //Go through the multicast filter table
+ for(i = 0; i < IPV4_MULTICAST_FILTER_SIZE; i++)
+ {
+ //Point to the current entry
+ entry = &interface->ipv4Context.multicastFilter[i];
+
+ //Valid entry?
+ if(entry->refCount > 0)
+ {
+ //The all-systems group (address 224.0.0.1) is handled as a special
+ //case. The host starts in Idle Member state for that group on every
+ //interface and never transitions to another state
+ if(entry->addr != IGMP_ALL_SYSTEMS_ADDR)
+ {
+ //Send an unsolicited Membership Report for that group
+ igmpSendReportMessage(interface, entry->addr);
+
+ //Set flag
+ entry->flag = TRUE;
+ //Start timer
+ entry->timer = time + IGMP_UNSOLICITED_REPORT_INTERVAL;
+ //Enter the Delaying Member state
+ entry->state = IGMP_STATE_DELAYING_MEMBER;
+ }
+ }
+ }
+ }
+ //Link down event?
+ else
+ {
+ //Go through the multicast filter table
+ for(i = 0; i < IPV4_MULTICAST_FILTER_SIZE; i++)
+ {
+ //Point to the current entry
+ entry = &interface->ipv4Context.multicastFilter[i];
+
+ //Valid entry?
+ if(entry->refCount > 0)
+ {
+ //Clear flag
+ entry->flag = FALSE;
+ //Enter the Idle Member state
+ entry->state = IGMP_STATE_IDLE_MEMBER;
+ }
+ }
+ }
+}
+
+
+/**
+ * @brief Process incoming IGMP message
+ * @param[in] interface Underlying network interface
+ * @param[in] buffer Multi-part buffer containing the incoming IGMP message
+ * @param[in] offset Offset to the first byte of the IGMP message
+ **/
+
+void igmpProcessMessage(NetInterface *interface,
+ const NetBuffer *buffer, size_t offset)
+{
+ size_t length;
+ IgmpMessage *message;
+
+ //Retrieve the length of the IGMP message
+ length = netBufferGetLength(buffer) - offset;
+
+ //Ensure the message length is correct
+ if(length < sizeof(IgmpMessage))
+ {
+ //Debug message
+ TRACE_WARNING("IGMP message length is invalid!\r\n");
+ //Silently discard incoming message
+ return;
+ }
+
+ //Point to the beginning of the IGMP message
+ message = netBufferAt(buffer, offset);
+ //Sanity check
+ if(message == NULL)
+ return;
+
+ //Debug message
+ TRACE_INFO("IGMP message received (%" PRIuSIZE " bytes)...\r\n", length);
+ //Dump message contents for debugging purpose
+ igmpDumpMessage(message);
+
+ //Verify checksum value
+ if(ipCalcChecksumEx(buffer, offset, length) != 0x0000)
+ {
+ //Debug message
+ TRACE_WARNING("Wrong IGMP header checksum!\r\n");
+ //Drop incoming message
+ return;
+ }
+
+ //Check the type field
+ switch(message->type)
+ {
+ //Membership Query message?
+ case IGMP_TYPE_MEMBERSHIP_QUERY:
+ //Process Membership Query message
+ igmpProcessQueryMessage(interface, message, length);
+ break;
+ //Membership Report message?
+ case IGMP_TYPE_MEMBERSHIP_REPORT_V1:
+ case IGMP_TYPE_MEMBERSHIP_REPORT_V2:
+ //Process Membership Query message
+ igmpProcessReportMessage(interface, message, length);
+ break;
+ //Unknown type?
+ default:
+ //Debug message
+ TRACE_WARNING("Unknown IGMP message type!\r\n");
+ //Discard incoming IGMP message
+ break;
+ }
+}
+
+
+/**
+ * @brief Process incoming Membership Query message
+ * @param[in] interface Underlying network interface
+ * @param[in] message Incoming Membership Query message
+ * @param[in] length Message length
+ **/
+
+void igmpProcessQueryMessage(NetInterface *interface,
+ const IgmpMessage *message, size_t length)
+{
+ uint_t i;
+ systime_t time;
+ systime_t maxRespTime;
+ Ipv4FilterEntry *entry;
+
+ //Get current time
+ time = osGetSystemTime();
+
+ //IGMPv1 Membership Query message?
+ if(message->maxRespTime == 0)
+ {
+ //The host receives a query with the Max Response Time field set to 0
+ interface->igmpv1RouterPresent = TRUE;
+ //Restart IGMPv1 router present timer
+ interface->igmpv1RouterPresentTimer = time + IGMP_V1_ROUTER_PRESENT_TIMEOUT;
+ //The maximum response time is 10 seconds by default
+ maxRespTime = IGMP_V1_MAX_RESPONSE_TIME;
+ }
+ //IGMPv2 Membership Query message?
+ else
+ {
+ //The Max Resp Time field specifies the maximum time allowed
+ //before sending a responding report
+ maxRespTime = message->maxRespTime * 10;
+ }
+
+ //Go through the multicast filter table
+ for(i = 0; i < IPV4_MULTICAST_FILTER_SIZE; i++)
+ {
+ //Point to the current entry
+ entry = &interface->ipv4Context.multicastFilter[i];
+
+ //Valid entry?
+ if(entry->refCount > 0)
+ {
+ //The all-systems group (224.0.0.1) is handled as a special case. The
+ //host starts in Idle Member state for that group on every interface
+ //and never transitions to another state
+ if(entry->addr != IGMP_ALL_SYSTEMS_ADDR)
+ {
+ //A General Query applies to all memberships on the interface from which
+ //the Query is received. A Group-Specific Query applies to membership
+ //in a single group on the interface from which the Query is received
+ if(message->groupAddr == IPV4_UNSPECIFIED_ADDR ||
+ message->groupAddr == entry->addr)
+ {
+ //Delaying Member state?
+ if(entry->state == IGMP_STATE_DELAYING_MEMBER)
+ {
+ //The timer has not yet expired?
+ if(timeCompare(time, entry->timer) < 0)
+ {
+ //If a timer for the group is already running, it is reset to
+ //the random value only if the requested Max Response Time is
+ //less than the remaining value of the running timer
+ if(maxRespTime < (entry->timer - time))
+ {
+ //Restart delay timer
+ entry->timer = time + igmpRand(maxRespTime);
+ }
+ }
+ }
+ //Idle Member state?
+ else if(entry->state == IGMP_STATE_IDLE_MEMBER)
+ {
+ //Switch to the Delaying Member state
+ entry->state = IGMP_STATE_DELAYING_MEMBER;
+ //Delay the response by a random amount of time
+ entry->timer = time + igmpRand(maxRespTime);
+ }
+ }
+ }
+ }
+ }
+}
+
+
+/**
+ * @brief Process incoming Membership Report message
+ * @param[in] interface Underlying network interface
+ * @param[in] message Incoming Membership Report message
+ * @param[in] length Message length
+ **/
+
+void igmpProcessReportMessage(NetInterface *interface,
+ const IgmpMessage *message, size_t length)
+{
+ uint_t i;
+ Ipv4FilterEntry *entry;
+
+ //Go through the multicast filter table
+ for(i = 0; i < IPV4_MULTICAST_FILTER_SIZE; i++)
+ {
+ //Point to the current entry
+ entry = &interface->ipv4Context.multicastFilter[i];
+
+ //Valid entry?
+ if(entry->refCount > 0)
+ {
+ //Report messages are ignored for memberships in
+ //the Non-Member or Idle Member state
+ if(entry->state == IGMP_STATE_DELAYING_MEMBER)
+ {
+ //The Membership Report message matches the current entry?
+ if(message->groupAddr == entry->addr)
+ {
+ //Clear flag
+ entry->flag = FALSE;
+ //Switch to the Idle Member state
+ entry->state = IGMP_STATE_IDLE_MEMBER;
+ }
+ }
+ }
+ }
+}
+
+
+/**
+ * @brief Send Membership Report message
+ * @param[in] interface Underlying network interface
+ * @param[in] ipAddr IPv4 address specifying the group address
+ * @return Error code
+ **/
+
+error_t igmpSendReportMessage(NetInterface *interface, Ipv4Addr ipAddr)
+{
+ error_t error;
+ size_t offset;
+ IgmpMessage *message;
+ NetBuffer *buffer;
+ Ipv4PseudoHeader pseudoHeader;
+
+ //Make sure the specified address is a valid multicast address
+ if(!ipv4IsMulticastAddr(ipAddr))
+ return ERROR_INVALID_ADDRESS;
+
+ //The all-systems group (224.0.0.1) is handled as a special case.
+ //The host never sends a report for that group
+ if(ipAddr == IGMP_ALL_SYSTEMS_ADDR)
+ return ERROR_INVALID_ADDRESS;
+
+ //Allocate a memory buffer to hold an IGMP message
+ buffer = ipAllocBuffer(sizeof(IgmpMessage), &offset);
+ //Failed to allocate memory?
+ if(buffer == NULL)
+ return ERROR_OUT_OF_MEMORY;
+
+ //Point to the beginning of the IGMP message
+ message = netBufferAt(buffer, offset);
+
+ //The type of report is determined by the state of the interface
+ if(interface->igmpv1RouterPresent)
+ message->type = IGMP_TYPE_MEMBERSHIP_REPORT_V1;
+ else
+ message->type = IGMP_TYPE_MEMBERSHIP_REPORT_V2;
+
+ //Format the Membership Report message
+ message->maxRespTime = 0;
+ message->checksum = 0;
+ message->groupAddr = ipAddr;
+
+ //Message checksum calculation
+ message->checksum = ipCalcChecksumEx(buffer, offset, sizeof(IgmpMessage));
+
+ //Format IPv4 pseudo header
+ pseudoHeader.srcAddr = interface->ipv4Context.addr;
+ pseudoHeader.destAddr = ipAddr;
+ pseudoHeader.reserved = 0;
+ pseudoHeader.protocol = IPV4_PROTOCOL_IGMP;
+ pseudoHeader.length = HTONS(sizeof(IgmpMessage));
+
+ //Debug message
+ TRACE_INFO("Sending IGMP message (%" PRIuSIZE " bytes)...\r\n", sizeof(IgmpMessage));
+ //Dump message contents for debugging purpose
+ igmpDumpMessage(message);
+
+ //The Membership Report message is sent to the group being reported
+ error = ipv4SendDatagram(interface, &pseudoHeader, buffer, offset, IGMP_TTL);
+
+ //Free previously allocated memory
+ netBufferFree(buffer);
+ //Return status code
+ return error;
+}
+
+
+/**
+ * @brief Send Leave Group message
+ * @param[in] interface Underlying network interface
+ * @param[in] ipAddr IPv4 address specifying the group address being left
+ * @return Error code
+ **/
+
+error_t igmpSendLeaveGroupMessage(NetInterface *interface, Ipv4Addr ipAddr)
+{
+ error_t error;
+ size_t offset;
+ NetBuffer *buffer;
+ IgmpMessage *message;
+ Ipv4PseudoHeader pseudoHeader;
+
+ //Make sure the specified address is a valid multicast address
+ if(!ipv4IsMulticastAddr(ipAddr))
+ return ERROR_INVALID_ADDRESS;
+
+ //The all-systems group (224.0.0.1) is handled as a special case.
+ //The host never sends a Leave Group message for that group
+ if(ipAddr == IGMP_ALL_SYSTEMS_ADDR)
+ return ERROR_INVALID_ADDRESS;
+
+ //If the interface state says the querier is running
+ //IGMPv1, this action should be skipped
+ if(interface->igmpv1RouterPresent)
+ return NO_ERROR;
+
+ //Allocate a memory buffer to hold an IGMP message
+ buffer = ipAllocBuffer(sizeof(IgmpMessage), &offset);
+ //Failed to allocate memory?
+ if(buffer == NULL)
+ return ERROR_OUT_OF_MEMORY;
+
+ //Point to the beginning of the IGMP message
+ message = netBufferAt(buffer, offset);
+
+ //Format the Leave Group message
+ message->type = IGMP_TYPE_LEAVE_GROUP;
+ message->maxRespTime = 0;
+ message->checksum = 0;
+ message->groupAddr = ipAddr;
+
+ //Message checksum calculation
+ message->checksum = ipCalcChecksumEx(buffer, offset, sizeof(IgmpMessage));
+
+ //Format IPv4 pseudo header
+ pseudoHeader.srcAddr = interface->ipv4Context.addr;
+ pseudoHeader.destAddr = IGMP_ALL_ROUTERS_ADDR;
+ pseudoHeader.reserved = 0;
+ pseudoHeader.protocol = IPV4_PROTOCOL_IGMP;
+ pseudoHeader.length = HTONS(sizeof(IgmpMessage));
+
+ //Debug message
+ TRACE_INFO("Sending IGMP message (%" PRIuSIZE " bytes)...\r\n", sizeof(IgmpMessage));
+ //Dump message contents for debugging purpose
+ igmpDumpMessage(message);
+
+ //The Leave Group message is sent to the all-routers multicast group
+ error = ipv4SendDatagram(interface, &pseudoHeader, buffer, offset, IGMP_TTL);
+
+ //Free previously allocated memory
+ netBufferFree(buffer);
+ //Return status code
+ return error;
+}
+
+
+/**
+ * @brief Get a random value in the specified range
+ * @param[in] max Upper bound
+ * @return Random value in the specified range
+ **/
+
+uint32_t igmpRand(uint32_t max)
+{
+ //Return a random value in the given range
+ return netGetRand() % (max + 1);
+}
+
+
+/**
+ * @brief Dump IGMP message for debugging purpose
+ * @param[in] message Pointer to the IGMP message
+ **/
+
+void igmpDumpMessage(const IgmpMessage *message)
+{
+ //Dump IGMP message
+ TRACE_DEBUG(" Type = 0x%02" PRIX8 "\r\n", message->type);
+ TRACE_DEBUG(" Max Resp Time = 0x%02" PRIX8 "\r\n", message->maxRespTime);
+ TRACE_DEBUG(" Checksum = 0x%04" PRIX16 "\r\n", ntohs(message->checksum));
+ TRACE_DEBUG(" Group Address = %s\r\n", ipv4AddrToString(message->groupAddr, NULL));
+}
+
+#endif
+