学步园

/*
利用操作系统提供的API编写防火墙.
该程序涉及到的API说明请访问微软的MSDN Library
代码在C++ Builder 5编译通过
如果您想和我交流请email:zzwinner@163.com
*/

#pragma hdrstop
#include "windows.h"
#include "Fltdefs.h"
//需要加载"iphlpapi.lib"

#pragma argsused
int main(int argc, char* argv[])
{
   //一个创建网络包过滤接口
   INTERFACE_HANDLE hInterface;
   PfCreateInterface(0,
      PF_ACTION_DROP,//PF_ACTION_FORWARD,
      PF_ACTION_DROP,//PF_ACTION_FORWARD,
      FALSE,
      TRUE,
      &hInterface);
   
   
   //绑定需要网络包过滤的IP地址
   BYTE localIp[] = {192,168,0,2};
   PfBindInterfaceToIPAddress(hInterface, PF_IPV4, localIp);
   
   //现在我们开始过滤HTTP协议的的接口
   FILTER_HANDLE fHandle;
   
   //填充过滤包的规则结构
   PF_FILTER_DESCRIPTOR inFilter;
   inFilter.dwFilterFlags = FD_FLAGS_NOSYN; //一直添这个值
   inFilter.dwRule = 0; //一直添这个值
   inFilter.pfatType = PF_IPV4; //用 ipV4 地址
   inFilter.SrcAddr = localIp; //设置本地IP地址
   inFilter.SrcMask = "/xff/xff/xff/xff"; //设置本地子网掩码
   inFilter.wSrcPort = FILTER_TCPUDP_PORT_ANY; //任意来源端口
   inFilter.wSrcPortHighRange = FILTER_TCPUDP_PORT_ANY;
   inFilter.DstAddr = 0; //任意目标地址
   inFilter.DstMask = 0;
   inFilter.wDstPort = 80; //目标端口 80(http 服务)
   inFilter.wDstPortHighRange = 80;
   inFilter.dwProtocol = FILTER_PROTO_TCP; // 过滤的协议
   
   //加入一个过滤接口
   PfAddFiltersToInterface(hInterface, 1, &inFilter, 0, NULL, &fHandle);
   //请在这设置一个调试断点,然后看看你的IE是否不能访问WEB页.
   
   //移出过滤接口
   PfRemoveFilterHandles(hInterface, 1, &fHandle);
   
   PfUnBindInterface(hInterface);
   PfDeleteInterface(hInterface);
   
   return 0;
}