网络通信程序设计实验二路由跟踪

实验报告课程名称 网络通信程序设计实验仪器 计算机 实验名称 路由跟踪 系别—计算机学院.专业班级/学号___学生姓名 实验日期 2014年4月6日成绩 指导教师 焦健实验二路由跟踪实验一、实验目的学习分析程序功能结构。熟悉ICMP协议的工作原理和路由跟踪的原理。掌握VC6.0下程序调试、运行的基本方法。二、实验原理路由跟踪的实现就是巧妙地利用了ICMP报文的TTL超时报文。其实现过程如下：源主机先向目的主机发送一个回应请求报文（类型8），TTL值设为1，第一个路由器收到后将TTL减1，这样TTL变为0，分组被废除。同时路由器向源主机发送一个TTL超时报文（类型为11），报文的IP包头中的源IP地址就是第一个路由器的地址，源主机就可以通过对该报文进行分析，得到第一个路由器的地址。接着发送TTL等于2的报文得到第二个路由器地址，再发TTL等于3的报文。如此下去直到收到目的主机的回应应答报文（类型为0）或目的不可达报文（类型为3），或者到了最大跳数（要检测路由器个数的最大值）。可以看到，对TTL的设置是实现跟踪的关键，使用函数setsockopt（m_Sock,IPPROTO_IP,IP_TTL,（LPSTR）&TTL,sizeof（int））可以对其进行设置，m_Sock是所创建的套接字，IP_TTL说明是进行TTL设置，TTL即是要设置的TTL值，为一个整形数值。其实现流程如图1所示图1路由跟踪流程图三、实验内容1、按照附录内容给RouteTrace程序添加代码，增加注释，调试程序通过。源代码：RouteTrace・cpp//RouteTrace.cpp:Definestheclassbehaviorsfortheapplication.#include"stdafx.h"#include"RouteTrace.h"#include"RouteTraceDlg.h"#ifdef_DEBUG#definenewDEBUG_NEW#undefTHIS_FILEstaticcharTHIS_FILE[]=__FILE__;#endif///////////////////////////////////////////////////////////////////////////////CRouteTraceAppBEGIN_MESSAGE_MAP(CRouteTraceApp,CWinApp)//{{AFX_MSG_MAP(CRouteTraceApp)//NOTE-theClassWizardwilladdandremovemappingmacroshere.//DONOTEDITwhatyouseeintheseblocksofgeneratedcode!//}}AFX_MSGON_COMMAND(ID_HELP,CWinApp::OnHelp)END_MESSAGE_MAP()///////////////////////////////////////////////////////////////////////////////CRouteTraceAppconstructionCRouteTraceApp::CRouteTraceApp(){//TODO:addconstructioncodehere,//PlaceallsignificantinitializationinInitInstance}///////////////////////////////////////////////////////////////////////////////TheoneandonlyCRouteTraceAppobjectCRouteTraceApptheApp;///////////////////////////////////////////////////////////////////////////////CRouteTraceAppinitializationBOOLCRouteTraceApp::InitInstance(){AfxEnableControlContainer();//Standardinitialization//Ifyouarenotusingthesefeaturesandwishtoreducethesize//ofyourfinalexecutable,youshouldremovefromthefollowing//thespecificinitializationroutinesyoudonotneed.#ifdef_AFXDLLEnable3dControls(); //CallthiswhenusingMFCinasharedDLL#elseEnable3dControlsStatic();//CallthiswhenlinkingtoMFCstatically#endifCRouteTraceDlgdlg;m_pMainWnd=&dlg;intnResponse=dlg.DoModal();if(nResponse==IDOK){//TODO:Placecodeheretohandlewhenthedialogis//dismissedwithOK}elseif(nResponse==IDCANCEL){//TODO:Placecodeheretohandlewhenthedialogis//dismissedwithCancel}//Sincethedialoghasbeenclosed,returnFALSEsothatweexitthe//application,ratherthanstarttheapplication'smessagepump.returnFALSE;}源代码：ICMRcpp//ICMP.cpp:implementationoftheCICMPclass.#include"stdafx.h"#include"RouteTrace.h"#include"ICMP.h"#include"ws2tcpip.h"#ifdef_DEBUG#undefTHIS_FILEstaticcharTHIS_FILE[]=__FILE__;#definenewDEBUG_NEW#endif////////////////////////////////////////////////////////////////////////Construction/Destruction//////////////////////////////////////////////////////////////////////CICMP::CICMP(){winsock=0;m_pIp=NULL;m_pIcmp=NULL;m_pIp=(IP_HEAD*)newBYTE[MAX_PACKET];m_pIcmp=(ICMP_HEAD*)newBYTE[MAX_PACKET];}CICMP::~CICMP(){delete[]m_pIp;delete[]m_pIcmp;}BOOLCICMP::Initialize(){WSADATAwsadata;if(WSAStartup(MAKEWORD(2,1),&wsadata)){ AfxMessageBox("WSAStartup初始化失败!");returnFALSE;}winsock=WSASocket(AF_INET,//建立socketSOCK_RAW,IPPROTO_ICMP,NULL,0,0);if(!winsock){AfxMessageBox("Socket创建失败!");returnFALSE;}inttimeout=5000;setsockopt(winsock,SOL_SOCKET,SO_RCVTIMEO,(char*)&timeout,//设置接收超时sizeof(timeout));timeout=5000;setsockopt(winsock,SOL_SOCKET,SO_SNDTIMEO,(char*)&timeout, //设置发送超时sizeof(timeout));returnTRUE;}voidCICMP::Uninitialize() //释放Socket{if(winsock)closesocket(winsock);WSACleanup();}USHORTCICMP::CheckSum(USHORT*buffer,intsize)//计算校验和{unsignedlongcksum=0;while(size>1){cksum+=*buffer++;size-=sizeof(USHORT);}if(size){cksum+=*(UCHAR*)buffer;}cksum=(cksum>>16)+(cksum&0xffff);cksum+=(cksum>>16);return(USHORT)(~cksum);}BOOLCICMP::SendICMPPack(char*pAddr){sockaddr_insockAddr;memset((void*)&sockAddr,0,sizeof(sockAddr));sockAddr.sin_family=AF_INET;sockAddr.sin_port=0;sockAddr.sin_addr.S_un.S_addr=inet_addr(pAddr);returnSendICMPPack(&sockAddr);}// 设置TTL intCICMP::SetTTL(intTTL){intnRet=setsockopt(winsock,IPPROTO_IP,IP_TTL,(LPSTR)&TTL,sizeof(int));if(nRet==SOCKET_ERROR){ CStringttlerr;ttlerr・Format(‘设置TTL错误!")；AfxMessageBox(ttlerr);return0；}return1；}// 发送 BOOLCICMP::SendICMPPack(sockaddr_in*pAddr){//填充ICMP数据各项intstate；char*p_data；m_pIcmp->type=ICMP_ECHO；m_pIcmp->code=0；m_pIcmp->ID=(USHORT)GetCurrentProcessId();m_pIcmp->number=0;m_pIcmp->time=GetTickCount();m_pIcmp->cksum=0;//填充数据p_data=((char*)m_pIcmp+sizeof(ICMP_HEAD));memset((char*)p_data,'0',DEF_PACKET);//检查和m_pIcmp->cksum=CheckSum((USHORT*)m_pIcmp,DEF_PACKET+sizeof(ICMP_HEAD));//发送数据state=sendto(winsock,(char*)m_pIcmp,DEF_PACKET+sizeof(ICMP_HEAD),NULL,(structsockaddr*)pAddr,sizeof(sockaddr));if(state==SOCKET_ERROR){if(GetLastError()==WSAETIMEDOUT)m_strInfo="连接超时!(发送)";elsem_strInfo="出现未知发送错误!"；returnFALSE;}if(state<DEF_PACKET){m_strInfo="发送数据错误!"；returnFALSE；}memcpy((void*)&m_sockAddr,(void*)pAddr,sizeof(sockaddr_in))；returnTRUE；}// 接收数据 BOOLCICMP::RecvICMPPack(){intstate;intlen=sizeof(sockaddr_in);char*addr;structhostent*lpHostent=NULL;intMaxfd=1;//监视的最大的文件描述符值+1fd_setreadFdSet;//设置文件描述符structtimevalTimeout;addr=inet_ntoa(m_sockAddr.sin_addr);FD_ZERO(&readFdSet);FD_SET(winsock,&readFdSet);Maxfd=max(Maxfd,winsock)+1;Timeout.tv_sec=10;//设置响应时间限制Timeout.tv_usec=0;inte=::select(Maxfd,&readFdSet,NULL,NULL,&Timeout);//获取多路复用套接字的响应结果if(e<=0){routeaddr="****";routestate=1;RouteState="超时未知"；returnFALSE；if(!FD_ISSET(winsock,&readFdSet))returnFALSE;state=recvfrom(winsock,(char*)m_pIp,MAX_PACKET,0,(structsockaddr*)&m_sockAddr,&len);if(state==SOCKET_ERROR){if(WSAGetLastError()==WSAETIMEDOUT){m_strInfo.Format("接收超时，路由跟踪失败!")；routestate=0;RouteState="路由跟踪失败!"；}elsem_strInfo="未知接收错误!"；returnFALSE；}//分析数据intipheadlen；ipheadlen=m_pIp->HeadLen*4；if(state<(ipheadlen+MIN_PACKET)){m_strInfo="目的地址的响应数据不正确"；returnFALSE；}ICMP_HEAD*p_icmprev；p_icmprev=(ICMP_HEAD*)((char*)m_pIp+ipheadlen)；switch(p_icmprev->type){caseICMP_ECHOREPLY://收到正常回显{m_strInfo.Format("接收到%s%d字节响应数据,响应时间:%dms・",inet_ntoa(m_sockAddr.sin_addr),len,GetTickCount()-p_icmprev->time);routeaddr=addr;routestate=0;RouteState="到达目的主机！"；returnTRUE;break；}caseICMP_TTLOUT:〃TTL超时{routeaddr=inet_ntoa(m_sockAddr・sin_addr)；routestate=1；RouteState="测试到路由器！"；returnTRUE；break；}caseICMP_DESUNREACH://目的不可达{m_strInfo="目的不可达！"；routestate=0；RouteState="目的不可达"；returnTRUE；break；

default:{routestate=0;routeaddr="***";m_strInfo="未知错误！"；RouteState="不明状态！"；}}returnTRUE;}2、命令行窗口下运行：tracert命令，记录运行结果和网站IP地址。dq：\Timj01S\systea.32^CBd・ezehicvcsoftUindou?XP 5.1.2660]<C>版取祈有1985-2001MicioooftCorp.SDocurientsandSettIngsMhduiinIstrator>tFaceFtww・丄石3・coiloneramaximumof39hops:1<1ns<1ms<1ms2oneramaximumof39hops:1<1ns<1ms<1ms2<1ns<1ms<1tins.13<1ns<1ms<1nsd<1ms<1ms262.112.G.E5rms<1ms<1ms0G1R13：7ms7PiS071ns1msims丄1»1ns1ms丫ms112.41.17891ns1ms1ms82te***Requesttimedout.it***Reuuesttimedout.121ns1ms1ms162.105.2B.233[IpacecompleteaTracingI'onteto163.xdwscache.glhB・I[162.105.28・2333C；SDociinientsandSetl^iriigrsM^dniinistri<i1;uri>险歌拼咅半;接收到1迄接收到1迄105.2S.233出字节响应数据，响应时间：口佔.目的地址|1S2.105.2B.233 三|壘丈眺數『蹶二劇壘丈眺數路由器地址162.105.28.233

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