Research and Implementation of Packet Filter Based on Filter-Hook Driver

A intercept's technology of network packet is proposed in windows 2000/XP operating system. Filter hook driver is analyzed based on working principle and realization. The technology cleverly links filter-hook to system's acquiescent IP filter-hook,Based on this,accomplish filter of packet. It's main basis that the function which is provided by ipfiltdrv.sys to intercept network packet.