Linux Network Architecture

by Wehrle, Klaus; Pahlke, Frank; Ritter, Hartmut; Muller, Daniel; Bechler, Marc

• ISBN13: 9780131777200
• ISBN10: 0131777203
• Edition: 1st
• Format: Paperback
• Copyright: 2004-04-29
• Publisher: Pearson

Summary

This unique Linux networking tutorial/reference by experts provides readers with a practical overview and understanding of the implementation of networking protocols in the Linux kernel. The book shows how networking behavior and protocols can be implemented within the Linux operating system. The book provides an introduction to the Linux kernel, mainly focusing on the upcoming kernel version 2.4 but also valid for version 2.2 kernels. The organization of the book follows the TCP/IP layering model, beginning with the kernel's network device drivers, continuing with link-layer protocols such as PPP, and finally giving a description of all core protocols of the TCP/IP protocol family. Additional supplementary protocols such as RSVP, IP Security, and Mobile IP are also covered.

Table of Contents

Preface

The Linux Kernel

Introduction

Architecture of Network Implementation

Layered Architectures, Services and Protocols

Overview of the Linux Network Implementation

Managing Packet Buffers

Network Devices

Layer I & Iimedium Access and Logical Link Layer

Introduction

The Serial Line Internet Protocol (SLIP)

The Point-to-Point Protocol (PPP)

PPP Over Ethernet

ATM on Linux

Transparent Bridges

Layer Iiinetwork Layer

Introduction

The Internet Protocol

IP Routing

The Address Resolution Protocol (ARP)

Group Communication with IP Multicast

IP Security with FreeS/WAN

Quality of Service Using the Traffic Control Tools

Packet Filters and Firewalls

Connection Tracking

Network Address Translation (NAT)

Quality of Service with KIDS

IPv6: The Internet Protocol Version 6

Layer Ivtransport Layer

Introduction

Transmission Control Protocol (TCP)

User Datagram Protocol (UDP)

Layer Vapplication Layer

Network Programming with Sockets

Mobile IP

RSVP Example of an Object-Oriented Protocol

Appendix

The LXR Source Code Browser

Debugging in the Linux Kernel

Important Network Administration Tools

Example Network Driver

Example Kernel Module

Table of Contents provided by Publisher. All Rights Reserved.

Excerpts

This book deals with the architecture of the network subsystem in the Linux kernel. The idea for this book was born at the Institute of Telematics at the University of Karlsruhe, Germany, where the Linux~kernel has been used in many research projects and its network functionality is modified or enhanced, respectively, in a targeted way. For instance, new services and protocols were developed for the next-generation Internet, and their behavior was studied. In addition, existing protocols, such as the TCP transport protocol, were modified to improve their behavior and adapt them to the new situation in the Internet.In the course of these research projects, it has been found that the Linux kernel is very suitable for studying new network functionalities, because it features a stable and extensive implementation of the TCP/IP protocol family. The freely available source code allows us to modify and enhance the functionality of protocol instances easily. In addition, the enhancement of the kernel functionality is very elegantly supported by the principle of the kernel modules. However, many studies and theses in this field showed that familiarization with the Linux network architecture, which is required before you can modify the behavior of a protocol instance, demands considerable work and time. Unfortunately, this is mainly due to the facts that the network subsystem of the Linux kernel is poorly documented and that there is no material that would explain and summarize the basic concepts.Although there are a few books that deal with the Linux kernel architecture and introduce its basic concepts, none of these books includes a full discussion of the network implementation. This situation may be due to the following two reasons: The network subsystem in the Linux kernel is very complex. As mentioned above, it implements a large number of protocols, which is probably one good reason for the enormous success of Linux. Both BoCe00 and BBDK+Ol mention that the description of all these protocols and their concepts would actually fill an entire book. Well, you are reading such a book now, and, as you can see, it has eventually turned out to be quite a large volume, although it describes only part of the network functionality, in addition to the basic concepts of the Linux network architecture. Operating-system developers normally deal with the classical topics of system architecture--for example, the management of memories, processes, and devices, or the synchronization of parallel activities in a system-rather than with the handling of network packets. As you go along in this book, you will surely notice that it has been written not by system developers, but by computer-science specialists and communication engineers.While considering the facts that there was little documentation covering the Linux network architecture and that students had to familiarize themselves with it over and over again, we had the idea of creating a simple documentation of the Linux network architecture ourselves. Another wish that eventually led to the more extensive concept of this book was a stronger discussion of important communication issues:design and implementation of network protocols in real-world systems.Networking courses teach students the most important concepts and standards in the field of telecommunication, but the design and implementation of network functionality (mainly of network protocols) by use of computer-science concepts has enjoyed little attention in teaching efforts, despite the fact that this knowledge could have been used often within the scope of studies and theses. The authors consider the description of the implementation of the Linux network architecture and its structure, interfaces, and applied concepts a step towards strengthening the informatics component in networking classes.The authors hope that this book will help to make the processes and structur