MFC下WinCap 4.02入门指南：利用WinCap进行网络抓包

最近需要设计网络抓包方面的软件，WinCap在这方面还是挺有名气的，于是下载了一个WinCap 4.02做了点研究由于本人一直在用MFC做一些设计，所以这里就MFC下使用WinCap4.02写点心得，主要目的是总结和帮助新手们更快地入门。
一、配置
第一步：下载官方主页上的WinCap安装包和开发包(Develop)
第二步： 为方便使用把开发包里面的include文件下的.h文件添加入VC6的include文件夹下面，把lib文件夹下面的.lib文件添加入vc6的lib文件夹下面。
好了现在在开发MFC项目的使用要使用wincap只需要在项目文档中加入应用#include "pcap.h"，在编译器选项当中增加连接库wcap.lib 和wsock32.lib两个，然和就可以使用wincap提供的函数了。
二、基本的程序
使用wincap最简单的应用是抓包，抓tcp/ip数据包。其他的就先不看了，直接运行开发包里面给的examples，看看文件：pktdump.h
/*
 * Copyright (c) 1999 - 2005 NetGroup, Politecnico di Torino (Italy)
 * Copyright (c) 2005 - 2006 CACE Technologies, Davis (California)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the Politecnico di Torino, CACE Technologies
 * nor the names of its contributors may be used to endorse or promote
 * products derived from this software without specific prior written
 * permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */


#include <stdlib.h>
#include <stdio.h>

#include <pcap.h>

#define LINE_LEN 16


int main(int argc, char **argv)
{ 
 pcap_if_t *alldevs, *d;
 pcap_t *fp;
 u_int inum, i=0;
 char errbuf[PCAP_ERRBUF_SIZE];
 int res;
 struct pcap_pkthdr *header;
 const u_char *pkt_data;
 
 printf("pktdump_ex: prints the packets of the network using WinPcap./n");