说明：  讨论了各种常用的网络封包截获方法，包括传输层过滤驱动程序、NDIS中间驱动程序Winsock2 SPI，然后以Xfilter个人防火墙为实例，从功能分析、模块设计、界面设计等介绍了软件开发的全过程。
(Discussed a variety of commonly used network packet interception methods, including the transport layer filter driver, NDIS intermediate driver Winsock2 SPI, then Xfilter personal firewall as an example, from the functional analysis, module design, interface design describes the whole process of software development .)