大型论坛检测系统开发与应用（终稿）.doc

大型论坛检测系统的开发与应用 摘 要 互联网发展迅速，网络论坛也随之发展起来。它在给人们带来了诸多方便的同时也产生了诸如传播色情暴力、发表反动言论和泄漏技术机密等一系列严重的问题。因此人们对网络论坛内容监测的需求已经迫在眉睫，而对它的深入分析和研究就更具有极为重要的意义。 本文介绍了网络基础知识、网络监测和过滤的原理以及数据从客户端传到服务器端的方式。分析了互联网论坛监测系统的目的、系统的组成原理和系统的功能模块。其主要模块包括包捕获模块、解码模块、模式匹配模块。它还提出了利用以太网的广播特性，在共享式网络环境下使用BPF技术来获取传输中的信息。系统在Linux操作系统下，调用Libpcap库函数来实现抓包，对包中的内容进行分析，找出有害的信息，从而实现过滤功能。利用文中介绍的方法来构建监测系统，能起到一定的监测作用。 关键词：论坛监测；抓包；过滤；伯克利数据包过滤器 Design and Implementation of the Internet Forum Detective System Abstract As the internet has been developing rapidly, the internet forum has brought many convenient to the people. But at the same time, it also has been having a series of questions, such as spreads the pornography, declares the reactionary opinion, divulges the secret of technology, etc. Therefore the requirement of the Internet forum detective system has been stared in the face, and thorough analysis for the system has the extremely vital significance. The thesis introduces the base knowledge of network, the principle of the network detecting and filter. Pointed out a method of how the data transport from the customer to the server. The thesis has analyzed the goal of internet forum detective system, the principle of system composition and the function module. The important module includes the module of capture package, module of decode, module of matching. The system proposes the broadcast characteristic of Ethernet, using the BPF technology to gain the network information in the common network environment. The system has base on Linux operation system, transferring a libpcap storeroom function to grasp the package, analyzing the content of the package and finding the bad message in order to realize the function of filter. The thesis uses the method which was referred just now to construct the system detective, and it realizes some of its functions. Key words: The forum detecting; Libpcap; filter; BPF 目 录