IP包过滤（转）

/*
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;
}