上机1：基于WinPcap的网络嗅探器设计与实现.doc

上机1：基于WinPcap的网络嗅探器设计1、目的与要求掌握基于WinPcap的网络编程模式。理解并能应用WinPcap设计并实现网络数据包的捕获与解析。2、设备与上机环境l 连网PC机（至少一台）。l 计算机硬件要求：Intel Pentium5 处理器、256MB以上内存，Ethernet网卡，网线若干。l 计算机软件要求：MS Windows 9x/2000/XP操作系统，TCP/IP协议，WinPcap430，Visual c+6.0/.net系统。3、上机内容与步骤：在程序设计之前，请参照提供的软件安装WinPcap。之后，按照如下步骤操作：步骤1：在VC+ 6.0下创建一个DOS命令行程序，工程名：自己的学号-PacketDump步骤2：打开main()函数，在主程序中增加如下头文件和常量定义：#include #define LINE_LEN 16pcap_if_t *alldevs, *d;pcap_t *fp;u_int inum, i=0;char errbufPCAP_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);printf( Usage: pktdump_ex -s sourcenn Examples:n pktdump_ex -s file.acpn pktdump_ex -s DeviceNPF_C8736017-F3C3-4373-94AC-9A34B7DAD998nn);if(argc next)printf(%d. %sn , +i, d-name);if (d-description)printf( (%s)n, d-description);elseprintf( (No description available)n);if (i=0)printf(nNo interfaces found! Make sure WinPcap is installed.n);return -1;printf(Enter the interface number (1-%d):,i);scanf(%d, &inum);if (inum i)printf(nInterface number out of range.n);/* Free the device list */pcap_freealldevs(alldevs);return -1;/* Jump to the selected adapter */for (d=alldevs, i=0; inext, i+);/* Open the adapter */if (fp = pcap_open_live(d-name,/ name of the device65536,/ portion of the packet to capture. / 65536 grants that the whole packet will be captured on all the MACs.1,/ promiscuous mode (nonzero means promiscuous)1000,/ read timeouterrbuf/ error buffer) = NULL)fprintf(stderr,nError opening adaptern);return -1;else /* Do not check for the switch type (-s) */if (fp = pcap_open_live(argv2,/ name of the device65536,/ portion of the packet to capture. / 65536 grants that the whole packet will be captured on all the MACs.1,/ promiscuous mode (nonzero means promiscuous)1000,/ read timeouterrbuf/ error buffer) = NULL)fprintf(stderr,nError opening adaptern);return -1;/* Read the packets */while(res = pcap_next_ex( fp, &header, &pkt_data) = 0)if(res = 0)/* Timeout elapsed */continue;/* print pkt timestamp and pkt len */printf(%ld:%ld (%ld)n, header-ts.tv_sec, header-ts.tv_usec, header-len);/* Print the packet */for (i=1; (i caplen + 1 ) ; i+)printf(%.2x , pkt_datai-1);if ( (i % LINE_LEN) = 0) printf(n);printf(nn);if(res = -1)printf(Error reading the packets: %sn, pcap_geterr(fp);return -1;pcap_close(fp);return 0;步骤3：为编译器指定包含文件和库文件搜索目录。假定WinPcap开发包WpdPack_4_0_2.zip被解压缩到C盘，如下图：为编译器指定包含文件和库文件搜索目录的方法如下：在VC+6.0下，打开Tools菜单，选择Options，然后选择Directories选项卡，指定WinPcap包含文件和库文件目录，如下图所示。步骤4：指定链接的库文件。方法：打开Project菜单，选择Settings，选择Link选项卡，然后把wpcap.lib