用原始套接字监听局域网内的数据包，解析ip头内的目的ip出现问题.txt

用原始套接字监听局域网内的数据包

用原始套接字监听局域网内的数据包，解析IP头内的目的IP出现问题

用原始套接字监听局域网内的数据包，为什么只能得到ip头内的源IP地址而目的IP地址总是会等于源IP地址？？     
奇怪了为什么就是不能得到目的IP地址？？


#include "stdafx.h"
#include <stdio.h>; 
#include <winsock2.h>; 
#include <ws2tcpip.h>; 
#include <Mstcpip.h>;
#pragma  comment(lib,"Ws2_32")
#define MAX_PACK_LEN    1024
typedef struct ip_hdr //定义IP首部 
{ 
unsigned char h_lenver; //4位首部长度,4位IP版本号 
unsigned char tos; //8位服务类型TOS 
unsigned short total_len; //16位总长度（字节） 
unsigned short ident; //16位标识 
unsigned short th_flag; //3位标志位 
unsigned char ttl; //8位生存时间 TTL 
unsigned char iProtocol; //8位协议 (TCP, UDP 或其他) 
unsigned short checksum; //16位IP首部校验和 
unsigned int sourceIP; //32位源IP地址 
unsigned int destIP; //32位目的IP地址 
}IP_HEADER; 

void DeCodeIP(char *buf,int iBufSize)  //解析侦听到的IP数据包

{

   IP_HEADER * pIPhdr;

  pIPhdr=(IP_HEADER * )buf;
        
  sockaddr_in dest,src;
  
  dest.sin_family=AF_INET;
  dest.sin_addr.S_un.S_addr=pIPhdr->;destIP;
  src.sin_family=AF_INET;
  src.sin_addr.S_un.S_addr=pIPhdr->;sourceIP;
  char *lpdest=inet_ntoa(dest.sin_addr);
  char *lpsrc=inet_ntoa(src.sin_addr);
  printf("dest:%s,src:%s\n",lpdest,lpsrc);

} 
int main(int argc, char* argv[])
{
        int iErrorCode;

char RecvBuf[MAX_PACK_LEN];

WSADATA wsaData;

iErrorCode = WSAStartup(MAKEWORD(2,2),&wsaData);

SOCKET SockRaw = WSASocket(AF_INET, SOCK_RAW, IPPROTO_IP, NULL, 0, WSA_FLAG_OVERLAPPED);

SOCKADDR_IN sa;

sa.sin_family = AF_INET;

sa.sin_port = htons(6000);

sa.sin_addr.S_un.S_addr=inet_addr("192.168.0.1");



if(bind(SockRaw, (PSOCKADDR)&sa, sizeof(sa))!=0)
{
        printf("bind error!");
        WSACleanup();
}


DWORD dwBufferLen[10] ;

DWORD dwBufferInLen=1;

DWORD dwBytesReturned=0;

iErrorCode=WSAIoctl(SockRaw, SIO_RCVALL,&dwBufferInLen, sizeof(dwBufferInLen), 

NULL, 0,&dwBytesReturned , NULL , NULL );//设置网卡为混杂模式以监听流过网卡的数据包
if(iErrorCode==SOCKET_ERROR)
{
        printf("ioctl error!");
        WSACleanup();
}


while(1)

{

        memset(RecvBuf, 0, sizeof(RecvBuf));
        iErrorCode = recv(SockRaw, RecvBuf, sizeof(RecvBuf),0);
        if(iErrorCode!=SOCKET_ERROR&&iErrorCode>;20)
        DeCodeIP(RecvBuf, iErrorCode);

}

        return 0;
}