Design And Implement Of Data Swapping System For PCI-based GAP

In recent years, network security risks deepening. And numbers of networksecurity incidents continue to occur. For government agencies, financial andresearch institutions, which have a very high level of network security requirements,they have to ensure the absolute safety of their internal net. And they also stronglyhope implementing data swap between internal network and external network tomeet certain business needs. How to implement data swap in the premise ofensuring network security is presented in front of the technical staff. So, GAPtechnology based on network isolation was born in this contextIn this paper,the author fullly study the current principles and techniques of GAPtechnology,and do deeply research on the data swap system of GAP which based onthe needs of enhancing city supervision proposed by the Ministry of publicsecurity.Firstly,the author propose a program of "2+1" system architecture based onPCI bus, and introduce the overall system structure and main function of each partin detail.Secondly,details the hardware design of data swap systerm of GAP,in whichThe author mainly design the interface circuit of PCI local bus,high-speed memorymodule and contral logic state machine based on FPGA technology.Finally,detailsthe software design of GAP,in which the author program the driver of PCI9054under Linux platform and HTTP proxy of interior network processing module.ThePCI9054driver implement the DMA operation of GAP hardware,which provideapplication program the interface functions of operating devices.And the HTTPproxy of interior network processing module is programmed by Multi-process andsocket technology under Linux platform,which implement HTTP proxy server，Protocol analysis module and protocol recovery module accoding to therequirements of GAP technology.Through simulation experiments,every module ofthe system achieves the desired function.