一段sniffer源码

#include <winsock2.h>
#include <stdio.h>
//#include <MsTcpIp.h>

/* 加这一句才不会提示：SIO_RCVALL没有定义 */
#define SIO_RCVALL _WSAIOW(IOC_VENDOR,1)
#pragma comment(lib, "Ws2_32")
void DecodeIPPacket(char *pData);

typedef struct _TCPHeader
{
 USHORT sourcePort;
 USHORT destinationPort;
 ULONG sequenceNumber;
 ULONG acknowledgeNumber;
 ULONG dataoffset;
 UCHAR flags;
 USHORT windows;
 USHORT checksum;
 USHORT urgentPointer;
}TCPHeader, *PTCPHeader;

void main()
{
 /*
 WSADATA wsaData;
 if(WSAStartup(MAKEWORD(2,2), wsaData) != 0)
 {
  return;
 }
 */

 char buff[1024];
 int nRet;
 DWORD dwValue = 1;

 SOCKET sRaw = socket(AF_INET, SOCK_RAW, IPPROTO_IP);
 char szHostName[56];
 SOCKADDR_IN addr_in;
 struct hostent *pHost;

 gethostname(szHostName, 56);;
 pHost = gethostbyname((char*)szHostName);
 if(pHost == NULL)
 return;

 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;
 
 if(ioctlsocket(sRaw, SIO_RCVALL, &dwValue) != 0) 
 return;
 
 while(TRUE)
 {
  nRet = recv(sRaw, buff, 1024, 0);
  if(nRet > 0)
  {
   DecodeIPPacket(buff);
  }
 }
}

void DecodeIPPacket(char *pData)
{
 TCPHeader *pTCPHdr = (TCPHeader*)pData;
 printf("port:%d -> %d\n", ntohs(pTCPHdr->sourcePort), ntohs(pTCPHdr->destinationPort));
}

不过怎么没有嗅到数据？奇怪。

（出处：清风网络学院）