可移植網路教學型作業系統的設計與實作

Abstract

TCP/IP網路包含了許多協定及各個協定的互動情形，但是幾乎所有的網路教科書都將各個協定分散在各個不同的章節作說明，而沒有詳細描述各個協定如何和其他協定作互動。為了補足教科書上的不足，目前有許多針對網路課程所設計的教學系統。Xinu也是其中之一，學生可以經由執行這套系統以及讀Xinu中的TCP/IP程式碼清楚地了解各個protocol如何和其他的協定的互動。雖然Xinu提供完整TCP/IP的技術，但因為Xinu是一套完整的作業系統直接執行於硬體上，有很大的系統移植與維護的問題。而這些問題也造成Xinu的難以普及。 在本篇論文中，我們根據Xinu的TCP/IP原始碼及Linux所提供的系統呼叫，開發實作出一個較為容易使用的網路教學系統。我們使用message passing 將TCP/IP移植成一個可以在Linux上執行的應用程式。除此之外，我們設計一個網路拓樸的模擬器，用來作為建置一個虛擬的網路環境。另外，根據我們開發的網路教學系統設計了三個網路課程的實作作業，經由實作的作業學生可以更加清楚地了解TCP/IP網路的概念。本篇論文將對使用message passing 把TCP/IP移植成應用程式和網路拓樸模擬器的實作加以闡述。TCP/IP protocol contains many protocols that interact with each other, but most networking textbooks discuss each protocol in different chapters and don’t describe how a protocol interacts with other protocols in the suite. In order to make students understand these network protocols solidly, many networking courseware are designed for tutors of the networking class. Xinu is a courseware for networking course, by doing projects over Xinu, students can understand clearly how each protocol interact with other protocols. Although Xinu is a good O.S. for teaching TCP/IP, it must be executed on a bare machine; that is, it is a real OS. Such kind of courseware suffers the problems of porting and maintenance. As a result, the prevalence of using Xinu in networking class is limited. In this thesis, we describe how we implement a networking courseware PIN/XINU which is based on XINU. We use message passing to make TCP/IP run as a user process under Linux. Besides, we designed a network topology simulator, which is used to build a virtual network environment. Furthermore, we use the networking courseware to design three networking assignments. Students can understand more clearly the TCP/IP networking concepts by completing these projects. Porting TCP/IP as user process, network topology simulator, and how we use the courseware for teaching the TCP/IP in networking classes are emphases of this thesis.