摘要
随着病毒、木马、黑客攻击等问题的出现，网络安全形势日渐严峻，网络安全产品也被人们重视起来。防火墙作为最早出现的网络安全产品和使用量最大的安全产品，也受到用户和研发机构的青睐。防火墙放置在外部网络与计算机之间作为隔离设备，可以识别并屏蔽非法请求，有效防止跨越权限的数据访问。
本文先介绍了个人防火墙开发的研究现状、VC++6.0和MFC程序的一些技术特点，然后对基于包过滤个人防火墙的开发进行了详细的介绍和描述。通过本文可以清楚地看到一个普通个人防火墙的开发过程。本防火墙中，用户可以自行设定过滤规则，以达到对不同源和不同目标的IP地址、端口和协议的过滤。允许用户将当前规则保存为*.rul的文件格式，供下次使用时直接导入。
本防火墙由以下几个模块组成：过滤规则添加模块，过滤规则显示模块，过滤规则存储模块，文件储存模块，安装卸载规则模块，IP封包过滤驱动功能模块。用户只需要通过主界面菜单和按钮就可以灵活地操作防火墙，有效地保护Windows系统的安全。
关键词：个人防火墙，包过滤，网络安全，MFC
Abstract
With the development of the Internet， security control equipment must be installed to ensure safety when the network involves a different level of trust. These control device are almost always some kind of firewall. With the growing problem of network security， the most users are increasingly concerning about network security products. Firewall， which is not only the first network security products but also has the most users， has been favored by users and R&D institutions. The personal firewall used in PC has largely become the protector of individual users’ security.
This article describes the development of personal firewall status， some technical characteristics of VC++6.0 and the MFC program， then gives a detailed introduction and description of a packet-filtering-based individual firewall’s development. A simple personal firewall development process can be clearly seen through this article. In the firewall， users can set their own filtering rules， in order to attain the filtering with different source IP， destination IP， source port， destination port and protocol. Program can be minimized into the system tray icon， protecting user in the background. It allows users to save the current rules into a file as *.rul.
The firewall is composed of the following modules: adding filter rules module， display filter rules module， storage filter rules module， storage file module， installation and unloading rules module， IP packet driver module. Users can finish the operation by using main menu and button and protect the system effectively.
Keywords：Personal Firewall， Packet Filter， Network Security， MFC
目录
摘要 I
Abstract II
目录 III
1 绪论 1
1.1 研究背景 1
1.2 研究意义 2
1.3 课题内容 3
2 包过滤防火墙技术 4
2.1 包过滤防火墙技术简介 4
2.2 防火墙包过滤技术的特点 4
2.3 包过滤防火墙工作原理 5
2.4 数据包过滤技术 7
2.5 数据包过滤类型 8
2.6开发工具 10
3 防火墙系统构成 12
3.1 需求分析 12
3.2 设计思路 12
3.3 功能模块构成 12
3.4 功能模块介绍 13
4 系统实现 14
4.1程序关键类 14
4.2详细设计 16
4.3驱动程序设计 22
5 程序结果测试 25
6 总结 28
参考文献 29
致谢 30
