计算机网络课程设计(4)

计算机网络

（二）、数据包的分析程序 程序代码：

#include #include #include #include #include #include #include

#define MAX_HOSTNAME_LAN 255

#define SIO_RCVALL _WSAIOW(IOC_VENDOR,1) #define MAX_ADDR_LEN 16

#pragma comment(lib,\

typedef struct tcpheader {

unsigned short int sport; //source address

unsigned short int dport; //destination address unsigned int th_seq; //sequence number unsigned int th_ack; //acknowledge number unsigned char th_x2:4; //header length unsigned char th_off:4; //reserved

unsigned char th_flag; //flags: URG ACK PSH RST SYN FIN unsigned short int th_win; //window size unsigned short int th_sum; //check sum unsigned short int th_urp; //urgent pointer }TCP_HDR;

struct ipheader {

unsigned char h_lenver; //version & header length unsigned char ip_tos; //tos

unsigned short int ip_len; //total length unsigned short int ip_id; //id unsigned short int ip_off; //offset

unsigned char ip_ttl; //time to live unsigned char ip_p; //protocal unsigned short int ip_sum; //check sum unsigned int ip_src; //source address

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计算机网络

unsigned int ip_dst; //destination address }IP_HDR;

typedef struct udphdr {

unsigned short sport; //source port unsigned short dport; //destination port unsigned short len; //UDP length

unsigned short cksum; //check sum(include data) } UDP_HDR;

typedef struct icmphdr {

unsigned short sport; unsigned short dport;

BYTE i_type; BYTE i_code; USHORT i_cksum; USHORT i_id; USHORT i_seq; ULONG timestamp; }ICMP_HDR;

void main() {

SOCKET sock; WSADATA wsd;

char RecvBuf[65535] = {0}; char entity_content[65535]={0}; char temp[65535]= {0}; DWORD dwBytesRet; int pCount=0;

unsigned int optval = 1; //the pointer , which shows us the payload begin unsigned char *dataip=NULL;

unsigned char *datatcp=NULL; //the pointer , which shows us the payload begin unsigned char *dataudp=NULL; unsigned char *dataicmp=NULL;

int lentcp=0, lenudp,lenicmp,lenip; int k;

char TcpFlag[6]={'F','S','R','P','A','U'}; //定义TCP的标志位 WSAStartup(MAKEWORD(2,1),&wsd);

if((sock = socket(AF_INET, SOCK_RAW,

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计算机网络

IPPROTO_IP))==SOCKET_ERROR) {

exit(0); }

char FAR name[MAX_HOSTNAME_LAN]; gethostname(name, MAX_HOSTNAME_LAN);

struct hostent FAR * pHostent;

pHostent = (struct hostent * )malloc(sizeof(struct hostent)); pHostent = gethostbyname(name);

SOCKADDR_IN sa;

sa.sin_family = AF_INET; sa.sin_port = htons(6000);

memcpy(&sa.sin_addr.S_un.S_addr, pHostent->h_addr_list[0], pHostent->h_length);

bind(sock, (SOCKADDR *)&sa, sizeof(sa));

//if you don't have raw socket support (win 95/98/me/win2kuser) it calls the exit(1) function

if ((WSAGetLastError())==10013) exit(0);

WSAIoctl(sock, SIO_RCVALL, &optval, sizeof(optval), NULL, 0, &dwBytesRet, NULL, NULL);

struct udphdr *pUdpheader; struct ipheader *pIpheader; struct tcpheader *pTcpheader; struct icmphdr *pIcmpheader;

char szSourceIP[MAX_ADDR_LEN], szDestIP[MAX_ADDR_LEN];

SOCKADDR_IN saSource, saDest; pIpheader = (struct ipheader *)RecvBuf;

pTcpheader = (struct tcpheader *)(RecvBuf+ sizeof(struct ipheader )); pUdpheader = (struct udphdr *) (RecvBuf+ sizeof(struct ipheader )); pIcmpheader = (struct icmphdr *) (RecvBuf+ sizeof(struct ipheader ));

int iIphLen = sizeof(unsigned long) * ( pIpheader->h_lenver & 0x0f ); while (1) {

memset(RecvBuf, 0, sizeof(RecvBuf));

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计算机网络

recv(sock, RecvBuf, sizeof(RecvBuf), 0);

saSource.sin_addr.s_addr = pIpheader->ip_src;

strncpy(szSourceIP, inet_ntoa(saSource.sin_addr), MAX_ADDR_LEN); //Check Dest IP

saDest.sin_addr.s_addr = pIpheader->ip_dst;

strncpy(szDestIP, inet_ntoa(saDest.sin_addr), MAX_ADDR_LEN); lenip=ntohs(pIpheader->ip_len);

lentcp =(ntohs(pIpheader->ip_len)-(sizeof(struct ipheader)+sizeof(struct tcpheader)));

lenudp =(ntohs(pIpheader->ip_len)-(sizeof(struct ipheader)+sizeof(struct udphdr)));

lenicmp =(ntohs(pIpheader->ip_len)-(sizeof(struct ipheader)+sizeof(struct icmphdr)));

if((pIpheader->ip_p)==IPPROTO_TCP&&lentcp!=0) {

pCount++;

dataip=(unsigned char *) RecvBuf; datatcp=(unsigned char *) RecvBuf+sizeof(struct ipheader)+sizeof(struct tcpheader); //data

entity_content[65535]=*datatcp;

printf(\数据包[%i]=%d字节数据###################\

printf(\协议头部*********************\\n\

printf(\标识:%i\\n\ printf(\总长度:%i\\n\ printf(\偏移量:%i\\n\ printf(\生存时间:%d\\n\ printf(\服务类型:%d\\n\ printf(\协议类型:%d\\n\

printf(\检验和:%i\\n\ printf(\源IP地址:%s \ printf(\目的IP地址:%s \

printf(\协议头部******************\\n\ printf(\源端口:%i\\n\ printf(\目的端口:%i\\n\ printf(\序列号:%i\\n\ printf(\应答号:%i\\n\

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计算机网络

printf(\检验和:%i\\n\ printf(\标志位：\

unsigned char FlagMask = 1; int t=0,j,p=0,i5=0; int lenhttp=0;

//print flags

for( k=0; k<6; k++ ) {

if((pTcpheader->th_flag) & FlagMask) printf(\ else

printf(\

FlagMask=FlagMask<<1; }

if(ntohs(pTcpheader->sport)==80||ntohs(pTcpheader->dport)==80) for(j=0;j

if( *(datatcp+j)==0x0d&&*(datatcp+j+1)==0x0a&&*(datatcp+j+2)==0x0d&&*(datatcp+j+3)==0x0a)

{

lenhttp=j;

printf(\协议******************\\n\

printf(\头部长度:%d\\n\ break; } }

for(k=0;k

if( *(datatcp+k)==0x42&&*(datatcp+k+1)==0x69&&*(datatcp+k+2)==0x74&&*(datatcp+k+3)==0x54&&*(datatcp+k+4)==0x6f&&*(datatcp+k+5)==0x72&&*(datatcp+k+6)==0x72&&*(datatcp+k+7)==0x65&&*(datatcp+k+8)==0x6e)

printf(\ }

for(int i3=0;i3

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