路由跟蹤器代碼.doc

/路由跟蹤器課程設計代碼部分/程序原理：程序發(fā)送一個請求回顯類型為8的icmp包，開始設置此包ttl為1，到達第一個路由器時，路由器會將ttl減1，此時ttl變?yōu)?，/ 路由器即會丟棄此包，并發(fā)送一個超時類型為11的icmp包，程序接收此包，解析出此包的源ip，即為第一個路由器的ip,依次類推，/ 發(fā)第二個請求回顯icmp包，ttl設置為2，第二個路由器也會像上面第一個一樣處理此包，即可獲得第二個路由器的ip, 這樣不斷的/ 增加icmp包ttl值，當ttl足夠大，icmp包可以到達目的地時，/ 目的地會發(fā)送一個回應應答報文或者是目的地不可達報文，此時路由跟蹤即完成#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位校驗和USHORT id; /16位標識符USHORT seq; /16位序列號 ICMP_HEADER;/報文解碼結構typedef structUSHORT usSeqNo; /序列號DWORD dwRoundTripTime; /往返時間in_addr dwIPaddr; /返回報文的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回顯應答報文usID=pIcmpHdr-id; /報文IDusSquNo=pIcmpHdr-seq; /報文序列號else if(pIcmpHdr-type=ICMP_TIMEOUT) /ICMP超時差錯報文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);/轉換不成功時按域名解析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)退出標志int iMaxHot=DEF_MAX_HOP; /循環(huán)的最大次數DECODE_RESULT DecodeResult; /傳遞給報文解碼函數的結構化參數while(!bReachDestHost&iMaxHot-)/設置IP報頭的TTL字段setsockopt(sockRaw,IPPROTO_IP,IP_TTL,(char *)&iTTL,sizeof(iTTL);coutiTTLcksum=0; /校驗和先置為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); /計算校驗和/記錄序列號和當前時間DecodeResult.usSeqNo=(ICMP_HEADER*)IcmpSendBuf)-seq; /當前序號DecodeResult.dwRoundTripTime=GetTickCount(); /當前時間/發(fā)送TCP回顯請求信息sendto(sockRaw,IcmpSendBuf,sizeof(IcmpSendBuf),0,(sockaddr*)&destSockAddr,sizeof(destSockAddr);/接收ICMP差錯報文并進行解析處理sockaddr_in from; /對端socket地址int iFromLen=sizeof(from); /地址結構大小int iReadDataLen; /接收數據長度while(1)/接收數據iReadDataLen=recvfrom(sockRaw,IcmpRecvBuf,MAX_ICMP_PACKET_SIZE,0,(sockaddr*)&from,&iFromLen);if(iReadDataLen!=SOCKET_ERROR) /有數據到達if(DecodeIcmpResponse(IcmpRecvBuf,iReadDataLen,DecodeResult,ICMP_ECHO_REPLY,ICMP_TIMEOUT)if(DecodeResult.dwIPaddr.s_addr=des