深入理解LINUX网络内幕（影印版）

Preface

Patti. GeneraIBackground

1. Introduction

Basic Terminology

Common Coding Patterns

User-Space Tools

Browsing the Source Code

When a Feature Is Offered as a Patch

2. Critical Data Structures

The Socket Buffer: sk_buff Structure

net_device Structure

Files Mentioned in This Chapter

3. User-Space-to-Kernel Interface

Overview

procfs Versus sysctl

ioctl

Netlink

Serializing Configuration Changes

Partll. Systemlnitialization

4. Notification Chains

Reasons for Notification Chains

Overview

Defining a Chain

Registering with a Chain

Notifying Events on a Chain

Notification Chains for the Networking Subsystems

Tuning via/proc Filesystem

Functions and Variables Featured in This Chapter

Files and Directories Featured in This Chapter

5. Network Device Initialization

System Initialization Overview

Device Registration and Initialization

Basic Goals of NIC Initialization

Interaction Between Devices and Kernel

Initialization Options

Module Options

Initializing the Device Handling Layer: net_dev_init

User-Space Helpers

Virtual Devices

Tuning via/proc Filesystem

Functions and Variables Featured in This Chapter

Files and Directories Featured in This Chapter

6. The PCl Layer and Network Interface Cards

Data Structures Featured in This Chapter

Registering a PCI NIC Device Driver

Power Management and Wake-on-LAN

Example of PCI NIC Driver Registration

The Big Picture

Tuning via/proc Filesystem

Functions and Variables Featured in This Chapter

Files and Directories Featured in This Chapter

7. Kernel Infrastructure for Component Initialization

Boot-Time Kernel Options

Module Initialization Code

Optimized Macro-Based Tagging

Boot-Time Initialization Routines

Memory Optimizations

Tuning via/proc Filesystem

Functions and Variables Featured in This Chapter

Files and Directories Featured in This Chapter

8. Device Registration and Initialization

When a Device Is Registered

When a Device Is Unregistered

Allocating net_device Structures

Skeleton of NIC Registration and Unregistration

Device Initialization

Organization of net_device Structures

Device State

Registering and Unregistering Devices

Device Registration

Device Unregistration

Enabling and Disabling a Network Device

Updating the Device Queuing Discipline State

Configuring Device-Related Information from User Space

Virtual Devices

Locking

Tuning via/proc Filesystem

Functions and Variables Featured in This Chapter

Files and Directories Featured in This Chapter

Part III. Transmission and Reception

9. Interrupts and Network Drivers

Decisions and Traffic Direction

Notifying Drivers When Frames Are Received

Interrupt Handlers

softnet_data Structure

10. Frame Reception

Interactions with Other Features

Enabling and Disabling a Device

Queues

Notifying the Kernel of Frame Reception: NAPI and netif_rx

Old Interface Between Device Drivers and Kernel: First Part of netif_rx

Congestion Management

Processing the NET RX SOFTIRQ: net rx action

11. Frame Transmission

Enabling and Disabling Transmissions

12. General and Reference Material About Interrupts

Statistics

Tuning via/proc and sysfs Filesystems

Functions and Variables Featured in This Part of the Book

Files and Directories Featured in This Part of the Book

13. Protocol Handlers

Overview of Network Stack

Executing the Right Protocol Handler

Protocol Handler Organization

Protocol Handler Registration

Ethernet Versus IEEE 802.3 Frames

Tuning via/proc Filesystem

Functions and Variables Featured in This Chapter

Files and Directories Featured in This Chapter

Part IV. Bridging

14. Bridging: Concepts

Repeaters, Bridges, and Routers

Bridges Versus Switches

Hosts

Merging LANs with Bridges

Bridging Different LAN Technologies

Address Learning

Multiple Bridges

15. Bridging: The Spanning Tree Protocol

Basic Terminology

Example of Hierarchical Switched L2 Topology

Basic Elements of the Spanning Tree Protocol

Bridge and Port IDs

Bridge Protocol Data Units (BPDUs)

Defining the Active Topology

Timers

Topology Changes

BPDU Encapsulation

Transmitting Configuration BPDUs

Processing Ingress Frames

Convergence Time

Overview of Newer Spanning Tree Protocols

16. Bridging:tinuxlmplementation

Bridge Device Abstraction

Important Data Structures

Initialization of Bridging Code

Creating Bridge Devices and Bridge Ports

Creating a New Bridge Device

Bridge Device Setup Routine

Deleting a Bridge

Adding Ports to a Bridge

Enabling and Disabling a Bridge Device

Enabling and Disabling a Bridge Port

Changing State on a Bridge Port

The Big Picture

Forwarding Database

Handling Ingress Traffic

Transmitting on a Bridge Device

Spanning Tree Protocol (STP)

netdevice Notification Chain

17. Bridging: Miscellaneous Topics

User-Space Configuration Tools

Tuning via/proc Filesystem

Tuning via/sys Filesystem

Statistics

Data Structures Featured in This Part of the Book

Functions and Variables Featured in This Part of the Book

Files and Directories Featured in This Part of the Book

Part V. Internet Protocol Version 4 (IPv4)

18. Internet Protocol Version 4 (IPv4): Concepts

IP Protocol: The Big Picture

IP Header

IP Options

Packet Fragmentation/Defragmentation

Checksums

19. Internet Protocol Version 4 (IPv4): tinux Foundations and Features .

Main IPv4 Data Structures

General Packet Handling

IP Options

20. Internet Protocol Version 4 (IPv4): Forwarding and Local Delivery ..

Forwarding

Local Delivery

21. Internet Protocol Version 4 (IPv4): Transmission

Key Functions That Perform Transmission

Interface to the Neighboring Subsystem

22. Internet Protocol Version 4 (IPv4): Handling Fragmentation

IP Fragmentation

IP Defragmentation

23. Internet Protocol Version 4 (IPv4): Miscellaneous Topics

Long-Living IP Peer Information

Selecting the IP Header's ID Field

IP Statistics

IP Configuration

IP-over-IP

IPv4: What's Wrong with It?

Tuning via/proc Filesystem

Data Structures Featured in This Part of the Book

Functions and Variables Featured in This Part of the Book

Files and Directories Featured in This Part of the Book

24. Layer Four Protocol and Raw IP Handling

Available L4 Protocols

L4 Protocol Registration

L3 to L4 Delivery: ip_local_deliver_finish

IPv4 Versus IPv6

Tuning via/proc Filesystem

Functions and Variables Featured in This Chapter

Files and Directories Featured in This Chapter

25. Internet Control Message Protocol (ICMPv4)

ICMP Header

ICMP Payload

ICMP Types

Applications of the ICMP Protocol

The Big Picture

Protocol Initialization

Data Structures Featured in This Chapter

Transmitting ICMP Messages

Receiving ICMP Messages

ICMP Statistics

Passing Error Notifications to the Transport Layer

Tuning via/proc Filesystem

Functions and Variables Featured in This Chapter

Files and Directories Featured in This Chapter

PartVl. Neighboring Subsystem

26. Neighboring Subsystem: Concepts

What Is a Neighbor?

Reasons That Neighboring Protocols Are Needed

Linux Implementation

Proxying the Neighboring Protocol

When Solicitation Requests Are Transmitted and Processed

Neighbor States and Network Unreachability Detection (NUD)

27. Neighboring Subsystem: Infrastructure

Main Data Structures

Common Interface Between L3 Protocols and Neighboring Protocols

General Tasks of the Neighboring Infrastructure

Reference Counts on neighbour Structures

Creating a neighbour Entry

Neighbor Deletion

Acting As a Proxy

L2 Header Caching

Protocol Initialization and Cleanup

Interaction with Other Subsystems

Interaction Between Neighboring Protocols and L3 Transmission

Functions

Queuing

28. Neighboring Subsystem: Address Resolution Protocol (ARP)

ARP Packet Format

Example of an ARP Transaction

Gratuitous ARP

Responding from Multiple Interfaces

Tunable ARP Options

ARP Protocol Initialization

Initialization of a neighbour Structure

Transmitting and Receiving ARP Packets

Processing Ingress ARP Packets

Proxy ARP

Examples

External Events

ARPD

Reverse Address Resolution Protocol (RARP)

Improvements in ND (IPv6) over ARP (IPv4)

29. Neighboring Subsystem: Miscellaneous lopics

System Administration of Neighbors

Tuning via/proc Filesystem

Data Structures Featured in This Part of the Book

Files and Directories Featured in This Part of the Book

Part VII. Routing

30. Routing: Concepts

Routers, Routes, and Routing Tables

Essential Elements of Routing

Routing Table

Lookups

Packet Reception Versus Packet Transmission

31. Routing: Advanced

Concepts Behind Policy Routing

Concepts Behind Multipath Routing

Interactions with Other Kernel Subsystems

Routing Protocol Daemons

Verbose Monitoring

ICMP_REDIRECT Messages

Reverse Path Filtering

32. Routing:tinuxlmplementation

Kernel Options

Main Data Structures

Route and Address Scopes

Primary and Secondary IP Addresses

Generic Helper Routines and Macros

Global Locks

Routing Subsystem Initialization

External Events

Interactions with Other Subsystems

33. Routing: The Routing Cache

Routing Cache Initialization

Hash Table Organization

Major Cache Operations

Multipath Caching

Interface Between the DST and Calling Protocols

Flushing the Routing Cache

Garbage Collection

Egress ICMP REDIRECT Rate Limiting

34. Routing: Routing Tables

Organization of Routing Hash Tables

Routing Table Initialization

Adding and Removing Routes

Policy Routing and Its Effects on Routing Table Definitions

35. Routing: tookups

High-Level View of Lookup Functions

Helper Routines

The Table Lookup: fn hash_lookup

fib_lookup Function

Setting Functions for Reception and Transmission

General Structure of the Input and Output Routing Routines

Input Routing

Output Routing

Effects of Multipath on Next Hop Selection

Policy Routing

Source Routing

Policy Routing and Routing Table Based Classifier

36. Routing: Miscellaneous Topics

User-Space Configuration Tools

Statistics

Tuning via/proc Filesystem

Enabling and Disabling Forwarding

Data Structures Featured in This Part of the Book

Functions and Variables Featured in This Part of the Book

Files and Directories Featured in This Part of the Book

Index