logo资料库

qualnet软件路由协议开发介绍.pdf

发布时间：2022-06-17 发布人：admin 分类：说明书 资料大小：0.23M 资料格式：pdf 举报 版权申诉
第1页 / 共16页
第2页 / 共16页
第3页 / 共16页
第4页 / 共16页
第5页 / 共16页
第6页 / 共16页
第7页 / 共16页
第8页 / 共16页
资料共16页，剩余部分请下载后查看
    Using QualNet – Part II Adding a Custom Protocol QualNet’s Directory Structure Directory addons bin contributed data documentation gui include interfaces kernel lib libraries license_dir main scenarios Contains Components developed as custom addons for specific customers Executable and other runtime files such as DLLs Models contributed by QualNet customers. Data files for the Wireless library: antenna configurations, modulation schemes and sample terrain User Guide, release notes, etc. Graphical components including icons, Java class files, and GUI configuration. QualNet kernel header files. Code to interface QualNet to 3rd party tools or external networks, such as HLA, STK, or IP networks. QualNet kernel objects used during the build process. Q g j p 3rd party software libraries used during the build process. Source code for model libraries such as Developer, Multimedia & Enterprise, & Wireless. License files and license libraries required for the build process. Kernel source files and Makefiles. Sample scenarios. 2
    QualNet Layered Architecture The simulation is a collection of network nodes, each with its own protocol stack parameters and statistics accessible from the “Node” structure accessible from the Node structure File include/node.h General node’s info Struct Node { : : : : }; nodeId; /* the user-specified node identifier */ NodeAddress Int32 globalSeed; /* seed for random number generator */ Int32 numNodes; /* number of nodes in the simulation */ /* Layer-specific information for the node. */ MacData** macData; // MAC layer M D t ** MacSwitch* switchData; // MAC switch NetworkData TransportData AppData : networkData; // network layer transportData; // transport layer appData; // application layer // MAC l D t Layer-specific info 3 Messages, Packets, and Timers A message is a unit defining an interaction between protocols and between nodes File include/message.h Two types of messages Packets (data or control) – used for communication between nodes Timers – allow protocols to schedule events in Timers allow protocols to schedule events in a future time 4
    Message-Related API Functions MESSAGE_Alloc() MESSAGE_InfoAlloc() MESSAGE_PacketAlloc() MESSAGE_AddHeader() MESSAGE_RemoveHeader() Allocate a message and provide it with standard event, layer, protocol info Allocate additional user-specified space for optional information about the event optional information about the event Allocate space for the packet within the message Add a header to the packet (usually called by each layer in the protocol stack) Remove a header from the packet MESSAGE_AddVirtualPayload() Add virtual payload to a Message (increase tx MESSAGE Duplicate() MESSAGE_Duplicate() MESSAGE_Send() MESSAGE_Free() delay without increasing array size) Copy the message including its packet and Copy the message, including its packet and user-specified space (info field) Send the message as an event to the specified layer and protocol Free the message, once it has reached its final destination 5 Packet Life Cycle Application MESSAGE_Alloc(…) MESSAGE_PacketAlloc(…) MESSAGE_Send(…) Transport MESSAGE_AddHeader() MESSAGE_Send(…) Application MESSAGE_Free(…) Transport MESSAGE_RemoveHeader() MESSAGE_Send(…) Routing IP MESSAGE_AddHeader() MESSAGE_Send(…) Routing MAC MESSAGE_AddHeader() MESSAGE_Send(…) IP MAC IP MESSAGE_RemoveHeader() MESSAGE_Send(…) MAC MESSAGE_RemoveHeader() MESSAGE_Send(…) Channel Channel Channel 6
    Creating Messages Message* MESSAGE_Alloc( Node *node Node *node, int layerType, int protocol, int eventType); A pointer to the node creating the message The stack layer at which this message will be processed next e.g., NETWORK_LAYER The specific protocol at the layer which will process this message e.g., ROUTING_PROTOCOL_DSR The event that this message represents e.g., MSG_NETWORK_FlushTables g p Message Processing Handling function for FlushTables event newMsg FlushTables CheckReplied RouteTimeout Check eventType field Check eventType field AODV… IP DSR Check protocolType field Radio MAC Network Transport App Check layerType field Event queue msg 7 8
    QualNet’s Protocol Modeling Initialization Function • Allocate memory for each node’s local variables • Initialize local variables • Process configuration file(s) • Process configuration file(s) • Schedule the first event Packet arrival or timer expiration Idle Finalization Function • Output statistics Message (packet or timer) processing function • Modify state variables • Update local statistics k t • Generate/forward packets t /f G d f f Adding a Protocol to QualNet Determine what layer your protocol will operate at Implement four/five main functions Initialization function Packet/event handling functions Router function (for routing protocol) Finalization function Hook up the above functions to the protocol dispatching functions of the corresponding layer f 9 10
    Example: Adding a New Routing Protocol Simplified Routing Information Protocol (SRIP) Table-driven, distance vector protocol Using periodic route update, no triggered update, no split horizon Working properly in static networks with only ) a small number of nodes (no node failure) ( Supporting only one interface (wireless) per node Distributed Bellman-Ford Algorithm What local information is maintained by each node? Routing Table Destination Next hop Cost : : : Initial routing table for A Destination Next hop Cost A B : A - - 0 ∞ ∞ What information is exchanged between neighboring nodes? Route Advertisement Destination Destination Cost Cost : : How a node processes a route advertisement? Node Aupdates its entry for destination Donly when the advertised cost to Dis lower than its current cost 11 12
    SRIP Header File (routing_srip.h) #ifndef _SRIP_H_ #define _SRIP_H_ #define SRIP_INFINITY 16 typedef struct srip_table_entry { destination; NodeAddress NodeAddress nextHop; unsigned int distance; } SripTableEntry; typedef struct srip_str { updateInterval; clocktype SripTableEntry* routingTable; /* statistic */ unsigned int numRouteUpdatesBroadcast; Routing table entry Local SRIP variables per nodes } SripData; void SripInit(Node* node, SripData** sripPtr, void SripHandleProtocolEvent(Node* node, Message* msg); void SripHandleProtocolPacket(Node* node, Message* msg, void SripFinalize(Node *node); void SripRouterFunction(Node* node, Message* msg, NodeAddress destAddr, const NodeInput* nodeInput, int interfaceIndex); NodeAddress sourceAddress); NodeAddress previousHopAddress, BOOL* packetWasRouted); Function prototypes to be recognized by QualNet’s network layer (IP) #endif 13 SRIP Initialization Function Called when each node is initialized by QualNet void SripInit(Node* node, SripData** sripPtr, const NodeInput* nodeInput const NodeInput nodeInput, int interfaceIndex) { int i; BOOL retVal; Message* newMsg; SripData* srip; if (MAC_IsWiredNetwork(node, interfaceIndex)) ERROR_ReportError("SRIP supports only wireless interfaces"); if (node->numberInterfaces > 1) ERROR_ReportError("SRIP only supports one interface of node"); Make sure the node has exactly one wireless interface /* allocate memory for SRIP's variables for this node */ srip = (SripData*) MEM_malloc(sizeof(SripData)); (*sripPtr) = srip; ( sripPtr) = srip; Allocate memory for local SRIP variables within each node /* read parameter from the configuration file */ IO_ReadTime(node->nodeId, ANY_ADDRESS, nodeInput, "SRIP-UPDATE-INTERVAL", &retVal, &(srip->updateInterval)); if (retVal == FALSE) ERROR_ReportError("SRIP-UPDATE-INTERVAL not specified!"); Read SRIP parameter from the main config file (to be continued) 14
    SRIP Initialization Function (continued) /* allocate and initialize the routing table for this node */ /* Note: (n+1) entries are allocated for convenience */ srip->routingTable = (SripTableEntry*) for (i = 1; i <= node->numNodes; i++) { for (i 1; i < node >numNodes; i++) { MEM_malloc(sizeof(SripTableEntry)*(node->numNodes+1)); srip->routingTable[i].destination = i; srip->routingTable[i].nextHop srip->routingTable[i].distance = SRIP_INFINITY; = INVALID_ADDRESS; } srip->routingTable[node->nodeId].nextHop srip->routingTable[node->nodeId].distance = 0; = node->nodeId; /* Initialize statistic */ srip->numRouteUpdatesBroadcast = 0; /* Tell IP to use our function to route packets */ NetworkIpSetRouterFunction(node, &SripRouterFunction, interfaceIndex); ROUTING_PROTOCOL_SRIP, MSG_NETWORK_RTBroadcastAlarm); /* schedule the very first route update broadcast */ /* after a random delay of 0 ~ srip->updateInterval-1 */ newMsg = MESSAGE_Alloc(node, NETWORK_LAYER, RandomSeed startupSeed; RANDOM_SetSeed(startupSeed, node->globalSeed, node->nodeId, clocktype delay = RANDOM_nrand(startupSeed)%srip->updateInterval; MESSAGE_Send(node, newMsg, pc_nrand(node->seed)%srip->updateInterval); ROUTING_PROTOCOL_SRIP, interface); } Initialize routing table Initialize statistic Register router function with IP Schedule the first route advertisement timer 15 SRIP Event Handling Function Called when a node’s timer expires void SripHandleProtocolEvent(Node* node, Message* msg) {{ int i, numEntries = 0, pktSize; Message* newMsg; char* pktPtr; /* Obtain a pointer to the local variable space */ SripData* srip = (SripData*) NetworkIpGetRoutingProtocol(node, ROUTING_PROTOCOL_SRIP); Obtain pointer to local variable space for (i = 1; i <= node->numNodes; i++) { if (srip->routingTable[i].distance < SRIP_INFINITY) numEntries++; Count the number of valid entries } newMsg = MESSAGE_Alloc(node, 0, 0, 0); pktSize = sizeof(unsigned int) + sizeof(SripTableEntry)*numEntries; pktSize sizeof(unsigned int) + sizeof(SripTableEntry) numEntries; MESSAGE_PacketAlloc(node, newMsg, pktSize, TRACE_ANY_PROTOCOL); pktPtr = newMsg->packet; memcpy(pktPtr, &numEntries, sizeof(unsigned int)); /* number of entries */ pktPtr += sizeof(unsigned int); /* Fill the packet with the valid table entries */ for (i = 1; i <= node->numNodes; i++) { if (srip->routingTable[i].distance < SRIP_INFINITY) { memcpy(pktPtr, &(srip->routingTable[i]), sizeof(SripTableEntry)); pktPtr += sizeof(SripTableEntry); } } Prepare a route advertisement packet (to be continued) 16
    分享到：
    赞 收藏

    相关推荐

    资料库

    网络技术

    共收录2367份资料，累计7个分类，关注成员有19位，主要包括：综合布线,网管软件,网络监控,网络设备,其它,系统集成,网络基础

    热门标签

    综合布线 网管软件 网络监控 网络设备 其它 系统集成 网络基础

    最新资料