路由跟蹤器代碼.doc

/路由跟蹤器課程設(shè)計(jì)代碼部分/程序原理：程序發(fā)送一個(gè)請求回顯類型為8的icmp包，開始設(shè)置此包ttl為1，到達(dá)第一個(gè)路由器時(shí)，路由器會(huì)將ttl減1，此時(shí)ttl變?yōu)?，/ 路由器即會(huì)丟棄此包，并發(fā)送一個(gè)超時(shí)類型為11的icmp包，程序接收此包，解析出此包的源ip，即為第一個(gè)路由器的ip,依次類推，/ 發(fā)第二個(gè)請求回顯icmp包，ttl設(shè)置為2，第二個(gè)路由器也會(huì)像上面第一個(gè)一樣處理此包，即可獲得第二個(gè)路由器的ip, 這樣不斷的/ 增加icmp包ttl值，當(dāng)ttl足夠大，icmp包可以到達(dá)目的地時(shí)，/ 目的地會(huì)發(fā)送一個(gè)回應(yīng)應(yīng)答報(bào)文或者是目的地不可達(dá)報(bào)文，此時(shí)路由跟蹤即完成#include #include #include using namespace std;#pragma comment(lib, Ws2_32.lib)typedef structunsigned char hdr_len:4; unsigned char version:4; unsigned char tos; unsigned short total_len; unsigned short identifier; unsigned short frag_and_flags; unsigned char ttl; unsigned char protocol; unsigned short checksum; unsigned long sourceIP; unsigned long destIP; IP_HEADER;typedef structBYTE type; /8位類型字段BYTE code; /8位代碼字段USHORT cksum; /16位校驗(yàn)和USHORT id; /16位標(biāo)識符USHORT seq; /16位序列號 ICMP_HEADER;/報(bào)文解碼結(jié)構(gòu)typedef structUSHORT usSeqNo; /序列號DWORD dwRoundTripTime; /往返時(shí)間in_addr dwIPaddr; /返回報(bào)文的IP地址DECODE_RESULT;USHORT checksum(USHORT *pBuf,int iSize)unsigned long cksum=0;while(iSize1)cksum+=*pBuf+;iSize-=sizeof(USHORT);if(iSize)cksum+=*(UCHAR *)pBuf;cksum=(cksum16)+(cksum&0xffff);cksum+=(cksum16);return (USHORT)(cksum);BOOL DecodeIcmpResponse(char * pBuf,int iPacketSize,DECODE_RESULT &DecodeResult,BYTE ICMP_ECHO_REPLY,BYTE ICMP_TIMEOUT)IP_HEADER* pIpHdr = (IP_HEADER*)pBuf;int iIpHdrLen = pIpHdr-hdr_len * 4;if (iPacketSize type=ICMP_ECHO_REPLY) /ICMP回顯應(yīng)答報(bào)文usID=pIcmpHdr-id; /報(bào)文IDusSquNo=pIcmpHdr-seq; /報(bào)文序列號else if(pIcmpHdr-type=ICMP_TIMEOUT) /ICMP超時(shí)差錯(cuò)報(bào)文char * pInnerIpHdr=pBuf+iIpHdrLen+sizeof(ICMP_HEADER); /載荷中的IP頭int iInnerIPHdrLen=(IP_HEADER *)pInnerIpHdr)-hdr_len*4; /載荷中的IP頭長ICMP_HEADER * pInnerIcmpHdr=(ICMP_HEADER *)(pInnerIpHdr+iInnerIPHdrLen);/載荷中的ICMP頭usID=pInnerIcmpHdr-id; /報(bào)文IDusSquNo=pInnerIcmpHdr-seq; /序列號elsereturn false;if(usID!=(USHORT)GetCurrentProcessId()|usSquNo!=DecodeResult.usSeqNo)return false;DecodeResult.dwIPaddr.s_addr=pIpHdr-sourceIP;DecodeResult.dwRoundTripTime=GetTickCount()-DecodeResult.dwRoundTripTime;if (pIcmpHdr-type = ICMP_ECHO_REPLY |pIcmpHdr-type = ICMP_TIMEOUT)if(DecodeResult.dwRoundTripTime)cout DecodeResult.dwRoundTripTimemsflush;elsecout 1msflush;return true;void main()WSADATA wsa;WSAStartup(MAKEWORD(2,2),&wsa);char IpAddress255;coutIpAddress;/得到IP地址u_long ulDestIP=inet_addr(IpAddress);/轉(zhuǎn)換不成功時(shí)按域名解析if(ulDestIP=INADDR_NONE)hostent * pHostent=gethostbyname(IpAddress);if(pHostent)ulDestIP=(*(in_addr*)pHostent-h_addr).s_addr;elsecout輸入的IP地址或域名無效!endl;WSACleanup();return;coutTracing roote to IpAddress with a maximum of 30 hops.ntype=ICMP_ECHO_REQUEST; pIcmpHeader-code=0; pIcmpHeader-id=(USHORT)GetCurrentProcessId();memset(IcmpSendBuf+sizeof(ICMP_HEADER),E,DEF_ICMP_DATA_SIZE);/ USHORT usSeqNo=0; int iTTL=1; BOOL bReachDestHost=FALSE; /循環(huán)退出標(biāo)志int iMaxHot=DEF_MAX_HOP; /循環(huán)的最大次數(shù)DECODE_RESULT DecodeResult; /傳遞給報(bào)文解碼函數(shù)的結(jié)構(gòu)化參數(shù)while(!bReachDestHost&iMaxHot-)/設(shè)置IP報(bào)頭的TTL字段setsockopt(sockRaw,IPPROTO_IP,IP_TTL,(char *)&iTTL,sizeof(iTTL);coutiTTLcksum=0; /校驗(yàn)和先置為0(ICMP_HEADER *)IcmpSendBuf)-seq=htons(usSeqNo+); /填充序列號(ICMP_HEADER *)IcmpSendBuf)-cksum=checksum(USHORT *)IcmpSendBuf,sizeof(ICMP_HEADER)+DEF_ICMP_DATA_SIZE); /計(jì)算校驗(yàn)和/記錄序列號和當(dāng)前時(shí)間DecodeResult.usSeqNo=(ICMP_HEADER*)IcmpSendBuf)-seq; /當(dāng)前序號DecodeResult.dwRoundTripTime=GetTickCount(); /當(dāng)前時(shí)間/發(fā)送TCP回顯請求信息sendto(sockRaw,IcmpSendBuf,sizeof(IcmpSendBuf),0,(sockaddr*)&destSockAddr,sizeof(destSockAddr);/接收ICMP差錯(cuò)報(bào)文并進(jìn)行解析處理sockaddr_in from; /對端socket地址int iFromLen=sizeof(from); /地址結(jié)構(gòu)大小int iReadDataLen; /接收數(shù)據(jù)長度while(1)/接收數(shù)據(jù)iReadDataLen=recvfrom(sockRaw,IcmpRecvBuf,MAX_ICMP_PACKET_SIZE,0,(sockaddr*)&from,&iFromLen);if(iReadDataLen!=SOCKET_ERROR) /有數(shù)據(jù)到達(dá)if(DecodeIcmpResponse(IcmpRecvBuf,iReadDataLen,DecodeResult,ICMP_ECHO_REPLY,ICMP_TIMEOUT)if(DecodeResult.dwIPaddr.s_addr=des