嵌入式不良網站過濾系統開發與性能提升之研究

Implementation and Performance Improvement of Embedded System Based Bad Sites Filter

張凱鈞(Kai-Chun Chang)

指導教授 ： 陳宏達

朝陽科技大學/資訊學院/資訊工程系/碩士(2010年)

摘要

一過濾不良網站的IP分享器被成功開發在ARM9嵌入式系統。本系統不僅是一個IP分享器，也是一個不良網站過濾器。具備NAT伺服器、DHCP伺服器、虛擬伺服器、PPPOE撥接、防火牆和DMZ等一些基本的IP分享器功能。額外的功能為可以設定不良網站過濾、國家頂級域名過濾、流量控制排程。透過這些過濾功能，防止青少年觀看色情、暴力或是誤入釣魚等不良網站，並可限制網路頻寬使用量。嵌入式系統的核心是使用Linux 2.6.24，架設mini_httpd網頁伺服器，使用者可以透過網頁介面來管理設定。使用shell腳本語言撰寫CGI網頁，相較於C撰寫的CGI網頁，所佔的儲存空間也較少。DHCP服務器不使用原本的udhcp，而是移植使用dnsmasq，有較穩定的效果。主要使用L7-filter過濾特定的網址、IP或國家頂級域名，可以獲得更快的過濾效果。

關鍵字

Embedded System ； Firewall ； Domain Name Filter ； Router ； NAT

並列摘要

A bad sites filter with IP sharing router was successful developed on ARM9 based embedded system. This system is not only an IP sharing router but also a bad sites filter. The basic functions of developed system are NAT server, DHCP server, Virtual server, PPPOE, firewall and DMZ which are compatible with the traditional IP sharing router. The extra functions of this system are the customized bad sites filtering, country code top level domain filtering, and schedule flow control. The bad site filtering functions can keep the teenager from the pornographic, fishing and violence websites. The schedule flow control can limit the internet usage. The operation system of this embedded system was the Linux 2.6.24. A mini_httpd web server was installed to perform web based management. Using shell script CGI other than C CGI could reduce the storage usage and increase the system performance. Using dnsmasq DHCP server instead of udhcp server could get higher efficiency operation. The L7-filter can filter out the specific domain names or country code top level domain names.

並列關鍵字

Embedded System ； Firewall ； Domain Name Filter ； Router ； NAT

參考文獻

[9] L7-filter supported protocols ，http://l7-filter.sourceforge.net/protocols

[10] Honda Chen, Pai-Fa Wu, and Yang-Yu Yeh, “Energy Benefits of Embedded Linux 2.6 in ARM9 Based SoC Systems”, Conference on Microelectronics Technology and Application, 2007, pp. 125-126

[12] Honda Chen, Chia-Wei Chen, and Yang-Yu Yeh "Development of IP and Domain Name Filter Using ARM9 Based Embedded System", "2009 The International Conference on Computer and Network Technologies in Education", Chung Hua University, Taiwan

[1] Netfilter home page，netfilter/iptables，http://www.netfilter.org/

[2] Open Systems Interconnection，http://www.itu.int/rec/T-REC-X.200-199407-I/en