Windows sistemler için ağ dosya sistemi müşteri programı
Network file systems client program for windows systems
- Tez No: 66486
- Danışmanlar: PROF. DR. EMRE HARMANCI
- Tez Türü: Yüksek Lisans
- Konular: Bilgisayar Mühendisliği Bilimleri-Bilgisayar ve Kontrol, Computer Engineering and Computer Science and Control
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 1997
- Dil: Türkçe
- Üniversite: İstanbul Teknik Üniversitesi
- Enstitü: Fen Bilimleri Enstitüsü
- Ana Bilim Dalı: Kontrol ve Bilgisayar Mühendisliği Ana Bilim Dalı
- Bilim Dalı: Belirtilmemiş.
- Sayfa Sayısı: 136
Özet
ÖZET Ağ Dosya Sistemi (Network File System, NFS), dosyaların ağ üzerinde saydam olarak paylaşımını sağlayan bir protokoldür. NFS hizmet biriminde bulunan dosya sistemlerini, müşteri makinalar kendi dosya sistemlerine dahil ederek kullanırlar. Müşteri makinalarda, uzak dosya sistemleri yerel dosya sistemi gibi gözükür, buna NFS' in saydamlığı denir. NFS dosya sistemi, UNIX' in standart mount komutuyla yerel dosya sistemine bağlanır ve tüm UNIX uygulamaları NFS dosya sistemlerinde yerel diskte bulunuyormuş gibi çalışır. NFS, ağdaki makinalarda ortak dosyaların birçok kopyasının bulunmasını önlediğinden sistem yönetimini kolaylaştırır. Tüm NFS müşterileri, dosyanın hizmet birimindeki tek kopyasını paylaşırlar. NFS kullanıcılar açısından da kolaylıklar sağlar. Birçok farklı sisteme girip dosyalan sistemler arasında taşımak yerine, kullanıcı bir tek yerden gerek duyduğu tüm dosyalara uygun bir dosya ağacı yapısı içinden erişebilir. Kullanıcı yerel veya uzak bir dosya arasındaki farkı anlayamaz. Bu aynım, Unix çekirdeği tarafından yapılır. NFS paylaşılan dosya sistemine sahip makina ve onu kullanmak isteyen makina arasında müşteri - hizmet birimi ilişkisi olan RPC tabanlı bir protokoldür. nfsd (NFS Daemon) olarak isimlendirilen NFS hizmet birimi süreci, müşteri makinalardan gelen RPC çağrılarım kabul eder. NFS hizmet birimleri dosya sistemleri için yapılan bağlantılandırma (mount) taleplerini kotarmak için rpc.mountd (RPC Mount Daemon) isimli bir süreci daha canlı tutar. NFS hizmet-alan tarafında NFS performansım arttırmak için biod (Block I/O Daemon) süreci de koşar, biod sürecinin çalışması zorunlu değildir. Bu çalışmada gerçeklenen NFS müşteri yazılımı, Windows işletim sistemi kullanan bilgisayarlara yöneliktir. Unix hizmet birimleri üzerindeki, NFS dosya sistemleri ile birlikte çalışmayı sağlar. Bu işlemleri gerçekleştirmek için, PCNFS, MOUNT ve NFS protokollerinin uyarlaması yapılmıştır. Bu yazılım, RPC yazılım geliştirme araçlarından yararlanılarak, C++ dilinde geliştirilmiştir.
Özet (Çeviri)
SUMMARY NETWORK FILE SYSTEMS CLIENT PROGRAM FOR WINDOWS SYSTEMS Today, a computing environment almost always refers to distributed computing, where users have workstations on their desks and shared resources are provided by special -purpose systems such as file, compute and print servers. Each workstation requires redundant configuration files, including user information, network host addresses and local and shared remote file system information. A mechanism to provide a consistent access to all files and configuration information ensures that all users have access to right machines and that once they have logged in they will see a set of files familiar and complete. This consistency must be provided in a way that is transparent to the users; that is a user should not know that a filesystem is located on a remote fileserver. The transparent view of resources must be consistent across all machines and also consistent with the way things work in non-networked environment. In a networked computing environment, it's usually up to the system administrator to manage both the machines on the network as well as the network itself. Managing the network means ensuring that the network is transparent to users rather than an impediment to their work. The Network File System (NFS) provides mechanisms for solving consistent and transparent access problems. The NFS were developed by Sun Microsystems Inc. NFS makes remote filesystems appear to be local, as if they were on disks attached to the local host. With NFS, all machines can share a single set of files, eliminating duplicate copies of files on different machines of network. NFS can be used to create very complex filesystems, taking components from many different servers on the network. It is possible to overwhelm users by providing everything everywhere so simplicity should rule network design. Sun Microsystems Inc. has taken on board the philosophy of distributed and open systems. Thus, from the beginning, NFS was designed so that it permitted the connection of computers from different manufacturers with very different operating systems running on them. Naturally, this philosophy was not followed without some selfishness. Sun Microsystems only produces workstations, which are primarily used in networks with systems from other manufacturers Nevertheless, the fact that NFS could be used in heterogeneous network environments was probably its greatest advantage over other products, such as AT&T' s Remote File System (RFS). Sun Microsystems trodden a completely new road. The specifications of the NFS protocol have been published and a reference implementation for Unix is available to all interested parties with a favourable price. Most manufacturers of Unix systems have ported this reference system or variant of it, to their computers. Thus, at least in Unix world, NFS has become the de facto standard for distributed file access and is today available for practically every Unix systems. VlllWhen NFS used, a number of services with very different functions are also exploited. For example, providing access to files involves the execution of administrative tasks in the network. An individual protocol is usually defined for each of these services. The NFS protocol of the same name is only used to access files. SunSoft, a company to which Sun Microsystems has hived off its operating system software activities since 1991, markets NFS and its associated protocols under the name Open Network Computing (ONC) The latest version of ONC, ONC+ was introduced in 1992. Its architecture is shown in Figure 1, in which the boxes shaded in grey represent the components of ONC+. Application Program I nm-sporı IodfepoKterit RPC/XDR TJJ/ Socket TCP/IP, IPX, OSI Figure 1 : ONC+ architecture. Classification of ONC Protocols ONC is based on a protocol layering that largely corresponds to the layering defined in the OSI model. The protocols shown in Figure 2 are those most often used in ONC products. ONC is theoretically protocol-independent; in other words, every layer of protocol hierarchy may be exchanged for functionally identical variant, transparently to the remaining system. In practice, however, this exchangeability is difficult to archieve and is usually only possible in certain groups of layers:. the subnetwork levels (layers 1 and 2). the transport levels (layers 3 and 4). the higher levels (layers 5,6 and 7) IXFigure 2: ONC Protocol Layers Internet Protocol (IP) The Internet Protocol (IP) is the cornerstone of the TCP/IP architecture and is both RFC 791 and ML-STD 1777. All computers in Internet understand IP. The main tasks of IP are addressing of the computers and the fragmentation of packets; it contains no functions for end-to-end message reliability or for flow control. IP makes the best effort to forward packets to the next destination, although this forwarding is not guaranteed. Main attributes of IP: connectionless protocol; fragments (divides) packets if necessary; addressing via 32-bit Internet addresses; 8-bit transport protocol addresses; maximum packet size of 65535 bytes; contains only a header checksum, no data checksum; protocol fields that are not always required are optional; finite packet lifetime; best-effort delivery. Transmission Control Protocol (TCP) The Transmission Control Protocol (TCP) is a protocol of transport layer, and thus lies above IP. Its main task is the reliable transportation of data through the network. TCP is specified in RFC 793 and in MIL-STD1778. Main attributes of TCP are:. Provides a fully duplex bidirectional virtual circuit.. As seen by user, data is transmitted as a data stream.. Reliable data transmission using - sequence numbers - the formation of checksums with acknowledgements of receipt - acknowledgements with timeout - segment retransmission after acknowledgement timeout.. Sliding-window principle for greater efficiency.. Urgent data and push function.. Transport-user addressing using 1 6-bit port number.. Graceful connection shutdown. User Datagram Protocol (UDP) The User Datagram Protocol (UDP) is a connectionless transport protocol. It is specified in RFC 768. Unlike TCP, UDP is a real lightweight. Its attributes are:. connectionless. addressing via port numbers. data checksums. very simple. best-effort forwarding. Remote Procedure Call (RPC) Remote Procedure Call (RPC) is a session-layer protocol, although this description is not completely true, since there is, admittedly,some mixing with the application protocols implemented using RPC. The RPC principle was originally developed by researchers working for Xerox. To implement NFS Sun's engineers developed their own RPC technology which is usually referred to as SunRPC or ONC/RPC in professional circles. ONC/RPC is used not only in the implementation of NFS, but also in many other networked applications. ONC/RPC is specified in RFC 1050. An RPC forms the basis for message exchange in all ONC applications. ONC/RPC may be used to design and implement network services, which as the name indicates, are used in a similar way to subroutine calls or procudes in high-level programming languages. This mode of working eases the programmer's tasks in the design and implementation of distributed programs. The creation of RPC clients, in other words the programming of RPC requests, can be simplified using tools. For this, one may use a compiler for a language in which the RPC requests, their parameters and return values are defined; the compiler generates the code to call the RPC run-time routines, known as stubs. Stubs have calling interfaces like normal procedures, so that they can be linked into a program like any other module and are transparent in the program code. A separete language is used for the definition for the following reasons:. A separate language makes the RPC system more independent of the programming language used to program the application program. The RPC compiler can, optionally, be provided with several code generators and can generate the stubs for different programming languages, such as C and Pascal, and their different calling syntaxes from a single definition of an RPC request.. The definition of RPC request can also be used to generate code for parts of RPC server that will later execute the procedure. XI. The management and control of the RPC system requires additional static parameters for the RPC request that are not provided for in the syntax of normal programming languages. A description of the definition language developed for ONC/RPC, the Remote Procedure Call Language and the associated compiler rpcgen can also be found. External Data Representation (XDR) Protocol External Data Representation (XDR) is a presentation layer protocol. If we define the term protocol to mean a declaration of the form of communication between two peers, then the XDR also falls into this category. As specified in RFC 1014, XDR is concerned with the definition of a format for data encoding. XDR does not have a protocol header or other protocol elements like other protocols. Network File System (NFS) Protocol The Network File System (NFS) protocol provides transparent remote access to shared file systems across network. The NFS protocol is designed to be machine, operating system, network architecture and transport protocol independent and consist of RPC procedures similar to the port mapper protocol. Table 1 shows the constants of the NFS service. The current version of the NFS protocol number is 3. Table 1 : RPC protocol paremeters for NFS version 3. Name Value Program number 100003 Version number 3 Transport protocol TCP, UDP Port number 2049 MOUNT Protocol The supporting MOUNT protocol performs the operating system-specific functions that allow clients attach remote directory trees to a point within the local file system. The mount process also allows the server to grant remote access privileges to a restricted set of clients via export control. Table 2 shows the constants of the MOUNT service. The current version of the MOUNT protocol number is 3. Table 2: RPC protocol parameters for MOUNT Name Value Program number 100005 Version number 3 Transport protocol TCP, UDP XUNFS Cüent Software :“İNFS”iNFS is a NFS client software for Windows 3.x operating systems. Main purpose of this implementation is providing transparent remote access to shared file systems across the network. This application is built on the following three protocols implementation.. PCNFS protocol for login to unix systems.. MOUNT protocol for linking unix filesystem.. NFS protocol for using unix filesystem operations.“iNFS”Application's User Interface iNFS application's user interface is based on the windowing system. Three windows and menus used by users. Main Window : This window is displayed at the firts run of the application. When“Bağlan”menu item is selected, the program asks for the remote unix sytem name, username, password and mounting to desired filesystem path on the unix system. Then, NFS Window and DOS Window are opened for file system operations. NFS Window : This window uses remote unix filesystems operations such as moving, copying, renaming, creating and removing directory, and displaying directory lists. The NFS Window's“Komutlar”menu includes the following menu items. NFS'den DOS'a Taşı: Move a file from remote NFS filesystem to local disc.. NFS'den DOS'a Kopyala: Copy a file from remote NFS filesystem to local filesystem.. Sil : Delete the selected file on the remote NFS filesystem.. Yeni İsimle Kaydet: Rename the selected file on the remote NFS filesystem. Katalog Yarat : Create a directory on the remote NFS filesystem.. Katalog Sil : Remove the selected directory on the remote NFS filesystem. DOS Window : This window uses local filesystems operations such as moving, copying, renaming, creating and removing directory, and displaying directory lists. DOS Window“Komutlar”menu includes the following menu items Xlll. DOS 'dan NFS 'e Taşı: Move a selected file from local filesystem to remote NFS filesystem.. NFS'den DOS'a Kopyala: Copy a selected file from local filesystem to remote NFS filesystem.. Sil : Delete the selected file on local filesystem.. Yeni İsimle Kaydet : Rename the selected file on the local filesystem. Katalog Yarat : Create a directory on the local filesystem.. Katalog Sil : Remove the selected directory on the local filesystem. Windows operations such as cascade, tile and arrange icons are supported with“Pencere”menu options. This application provides help support for NFS command related topics. XIV
Benzer Tezler
- Detection of sources being used on ddos attacks
Ddos ataklarında kullanılan kaynakların tespiti
YALDA MOTEVAKELKHOSROSHAHI
Yüksek Lisans
İngilizce
2019
Bilgisayar Mühendisliği Bilimleri-Bilgisayar ve Kontrolİstanbul Teknik ÜniversitesiBilgi Güvenliği Mühendisliği Ana Bilim Dalı
DOÇ. DR. ENVER ÖZDEMİR
- Linux sistemler için derinlemesine adli analiz yapılarak kalıcılık yapılarının tespit edilmesi
Detection of persistence structures by performing in-depth forensics analysis for linux systems
BÜŞRA AYTEKİN
Yüksek Lisans
Türkçe
2022
Bilgisayar Mühendisliği Bilimleri-Bilgisayar ve KontrolFırat ÜniversitesiAdli Bilişim Mühendisliği Ana Bilim Dalı
DOÇ. DR. FATİH ERTAM
- Ortak mimarili yapılar ile insansız araçlarda veri iletişimi
Data communication in unmanned systems using joint architecture
OKAN BOSTAN
Yüksek Lisans
Türkçe
2015
Bilgisayar Mühendisliği Bilimleri-Bilgisayar ve Kontrolİstanbul Teknik ÜniversitesiMekatronik Mühendisliği Ana Bilim Dalı
PROF. DR. HAKAN TEMELTAŞ
- Virmon: Sanallaştırma tabanlı otomatik bir dinamik zararlı yazılım analiz sistemi
Virmon: A virtualization-based automated dynamic malware analysis system
HÜSEYİN TİRLİ
Yüksek Lisans
Türkçe
2014
Bilgisayar Mühendisliği Bilimleri-Bilgisayar ve Kontrolİstanbul Teknik ÜniversitesiBilgisayar Bilimleri Ana Bilim Dalı
PROF. DR. TAKUHİ NADİA ERDOĞAN