IP数据包解析代码.doc

#include#include #include #include #pragma comment (lib,Ws2_32.lib)#define BUFFER_SIZE 65535#define FRAGMENT_SIZE 10000 /分片数据部分最长为10000#define FRAGMENT_NUM 7#define START 20#define IO_RCVALL _WSAIOW(IOC_VENDOR,1)typedef struct _IP_HEADER /定义IP头BYTE Version_HeadLen; /版本（前4位)和首部长度 BYTE ServiceType; /服务类型WORD TotalLen; /数据报总长WORD ID; /标识WORD Flags_FragOff; /标志（前3位）,后13位表示页偏移BYTE TimeToLive; /生存周期BYTE Protocol; /协议WORD HdrChksum; /头校验和DWORD SrcAddr; /源地址DWORD DstAddr; /目地地址IP_HEADER;void checksum(IP_HEADER *ip,WORD *sum)unsigned int sum_tmp;sum_tmp=MAKEWORD(ip-ServiceType,ip-Version_HeadLen)+ip-TotalLen+ip-ID+ip-Flags_FragOff+MAKEWORD(ip-Protocol,ip-TimeToLive)+ip-HdrChksum+(WORD)(ip-SrcAddr16)+(WORD)(ip-SrcAddr & 0xffff)+(WORD)(ip-DstAddr16)+(WORD)(ip-DstAddr & 0xffff);if(sum_tmp(216-1)sum_tmp=(unsigned short)sum_tmp+1;*sum=(WORD)(sum_tmp);char * parseServiceType_getProcedence(BYTE b)switch(b5)/获取服务类型字段中优先级子域case 7: return Network Control;/网络控制break;case 6:return Internet work Control; /网络控制break;case 5:return CRITIC/ECP; break;case 4:return Flash Override;/最优先信号break;case 3:return Flsah; break;case 2:return Immediate; break;case 1:return Priority;/协议break;case 0:return Routine;/路由break;default:return Unknow;break;char * parseServiceType_getTOS(BYTE b)b=(b1)&0x0f;/获取服务类型字段中的TOS子域switch(b) case 0:return Normal service; /正常运行break;case 1:return Minimize monetary cost; /成本break;case 2:return Maximize reliability; /可靠性break;case 4:return Maximize throughput; /吞吐量break;case 8:return Minimize delay; /延迟break;case 15:return Maximize security; /安全性break; default:return Unknow; char * getProtocol(BYTE Protocol) /获取协议字段共8位switch(Protocol) /以下为协议号说明： case 1:return ICMP; /Internet控制报文协议case 2:return IGMP; /Internet组管理协议case 4:return IP in IP;/移动IP数据封装和隧道case 6:return TCP;/传输控制协议case 8:return EGP;/外部网关协议case 17:return UDP;/用户数据报文协议case 41:return IPv6;case 46:return RSVP;/资源预留协议case 89:return OSPF;/Open Shortest Path First 开发式最短路径优先default:return UNKNOW;void ipparse(FILE* file,IP_HEADER *ip_pointer)fseek(file,0,SEEK_END);fprintf(file,版本号=%drn,ip_pointer-Version_HeadLen4);fprintf(file,报头标长= %d (BYTE)rn,(ip_pointer-Version_HeadLen & 0x0f)*4); /首部长度是以4个字节为单位的fprintf(file,服务器类型 = %s,%srn,parseServiceType_getProcedence(ip_pointer-ServiceType),parseServiceType_getTOS(ip_pointer-ServiceType);fprintf(file,总长度 = %d(BYTE)rn,ip_pointer-TotalLen);fprintf(file,标识 = %drn,ip_pointer-ID);fprintf(file,标志位 DF=%d , MF=%drn,(ip_pointer-Flags_FragOff14)&0x01),(ip_pointer-Flags_FragOff13)&0x01);fprintf(file,分段偏移值 = %drn,(ip_pointer-Flags_FragOff&0x1fff);fprintf(file,生存期 = %d (hops)rn,ip_pointer-TimeToLive);fprintf(file,协议 = %srn,getProtocol(ip_pointer-Protocol);fprintf(file,头校验和 = 0x%0xrn,ip_pointer-HdrChksum);fprintf(file,源IP地址 = %srn,inet_ntoa(*(in_addr*)&ip_pointer-SrcAddr);fprintf(file,目的IP地址 = %srn,inet_ntoa(*(in_addr*)&ip_pointer-DstAddr);fprintf(file,-rn);void assisgment(IP_HEADER *sou_pointer,IP_HEADER *des_pointer )des_pointer-Version_HeadLen=sou_pointer-Version_HeadLen;des_pointer-ServiceType=sou_pointer-ServiceType;des_pointer-TotalLen=sou_pointer-TotalLen;des_pointer-ID=sou_pointer-ID;des_pointer-TimeToLive=sou_pointer-TimeToLive;des_pointer-Protocol=sou_pointer-Protocol;des_pointer-SrcAddr=sou_pointer-SrcAddr;des_pointer-DstAddr=sou_pointer-DstAddr;void main()FILE* file;file=fopen(分片数据报头.txt,wb+);WORD rv;WSADATA WSAData; /定义了能够储存WSAStarup调用返回值的结构rv=MAKEWORD(2,2); /Winsock2版本WSAStartup(rv,&WSAData);SOCKET sock=socket(AF_INET,SOCK_RAW,IPPROTO_IP); /创建套接字，sock为套接字描述符BOOL flag=true;setsockopt(sock,IPPROTO_IP,IP_HDRINCL,(CHAR*)&flag,sizeof(flag);/任意类型、任意状态套接口的设置选项值char hostName128;gethostname(hostName,100); /获取主机名hostent * pHostIP;/获取本地IP地址pHostIP = gethostbyname(hostName);sockaddr_in addr_in;addr_in.sin_addr=*(in_addr *)pHostIP-h_addr_list0;addr_in.sin_family = AF_INET;addr_in.sin_port = htons(6000); /将无符号短整型主机数据转换为网络字节顺序数据bind(sock,(PSOCKADDR)&addr_in,sizeof(addr_in); DWORD dwBufferLen10; /设置网卡为混杂模式DWORD dwBufferInLen=1;DWORD dwBytesReturned=0;WSAIoctl(sock, IO_RCVALL,&dwBufferInLen,sizeof(dwBufferInLen),&dwBufferLen,sizeof(dwBufferLen),&dwBytesReturned,NULL,NULL);char bufferBUFFER_SIZE; /设置缓冲区int n=0; /n是一个标志用来使得输出更加调理char c;dosystem(cls); IP_HEADER fragment_HeaderFRAGMENT_NUM; int size=recv(sock,buffer,BUFFER_SIZE,0); /接收数据包 IP_HEADER ip=*(IP_HEADER*)buffer; int fragment_num=(ip.TotalLen-(ip.Version_HeadLen & 0x0f)*4)/FRAGMENT_SIZE+1;printf(nn接受到IP数据报的报头信息是n);if (size0) ipparse(file,&ip);ipparse(stdout,&ip); printf(nnIP数据报分片n);printf(-n);for(int j=0;jfragment_num;j+)assisgment(&ip,&fragment_Headerj);/对总长度标志位和页偏移赋值unsigned short flags_flagoff;unsigned short total_len;WORD cs;if(j!=fragment_num-1)flags_flagoff=j*FRAGMENT_SIZE/8+(short)8192; /8192对应的是标志位的MFtotal_len=FRAGMENT_SIZE+(unsigned short)(ip.Version_HeadLen&0x0f)*4);elseflags_flagoff=j*FRAGMENT_SIZE/8;total_len=ip.TotalLen%FRAGMENT_SIZE +(unsigned short)(ip.Version_HeadLen&0x0f)*4);fragment_Headerj.Flags_FragOff=(WORD)flags_flagoff;fragment_Headerj.TotalLen=total_len;fragment_Headerj.HdrChksum=0;/checksum(fragment_Headerj,c