Based On Transparent Proxy Linux

Transparent proxy is a client software,it can redirect network packets to proxy server according to the proxy rule which is set by user.This broughts great convenience to user who regular use proxy. Besides,how to defend the DDoS is a hot topic in information security area.Attacker controls many client machines to send network packet to the same network server at the same time,make the server denial of service. According to the characteristic of DDoS,we extend a network security module inside the transparent proxy which can defends DDoS from the source end.We use a new way to design this software because there are some difference between linux's kernel and windows's kernel,when we design,serval techniques have been used,they are TCP/UDP packet structure,socks5 protocol,libnet lib,netfilter framework,communications between kernel mode and user mode.First this paper introduces the backgrounds of transparent proxy,then the work steps of transparent proxy,and some main function model of it for linux,then come up with the relative techniques.This paper also go into particulars about socks5 protocol,libnet lib,netfilter framework,communications between kernel mode and user mode. Combine with these techniques, this paper instroduces the design scheme and implement details of transparent proxy and network security module.At last it summarizes the performed functions in this subject, and prospects for inprovement of this subject.