XMPP: The Definitive Guide: Building Real-Time Applications with Jabber Technologies

307 Pages·2009·15.428 MB·English

by  Kevin Smith, Peter Saint-Andre, Remko Troncon

XMPP: The Definitive Guide

XMPP: The Definitive Guide
Building Real-Time Applications with Jabber
Technologies
Peter Saint-Andre, Kevin Smith, and Remko Tronçon
Beijing • Cambridge • Farnham • Köln • Sebastopol • Taipei • Tokyo
XMPP: The Definitive Guide
by Peter Saint-Andre, Kevin Smith, and Remko Tronçon
Copyright © 2009 Peter Saint-Andre, Kevin Smith, Remko Tronçon. All rights reserved.
Printed in the United States of America.
Published by O’Reilly Media, Inc., 1005 Gravenstein Highway North, Sebastopol, CA 95472.
O’Reilly books may be purchased for educational, business, or sales promotional use. Online editions
are also available for most titles (http://safari.oreilly.com). For more information, contact our corporate/
institutional sales department: [phone] or [email protected].
Editor: Mary E. Treseler Indexer: Joe Wizda
Production Editor: Loranah Dimant Cover Designer: Karen Montgomery
Copyeditor: Genevieve d’Entremont Interior Designer: David Futato
Proofreader: Loranah Dimant Illustrator: Robert Romano
Printing History:
April 2009: First Edition.
Nutshell Handbook, the Nutshell Handbook logo, and the O’Reilly logo are registered trademarks of
O’Reilly Media, Inc. XMPP: The Definitive Guide, the image of a kanchil mouse deer on the cover, and
related trade dress are trademarks of O’Reilly Media, Inc.
JABBER® is a registered trademark licensed through the XMPP Standards Foundation.
Many of the designations used by manufacturers and sellers to distinguish their products are claimed as
trademarks. Where those designations appear in this book, and O’Reilly Media, Inc. was aware of a
trademark claim, the designations have been printed in caps or initial caps.
While every precaution has been taken in the preparation of this book, the publisher and authors assume
no responsibility for errors or omissions, or for damages resulting from the use of the information con-
tained herein.
ISBN: 978-0-596-52126-4
[M]
1243450993
Table of Contents
Preface ..................................................................... xi
Part I. An Overview of XMPP
1. Introduction ........................................................... 3
What Can You Do with XMPP? 3
Services 3
Applications 5
Brief History 7
Open Source and Open Standards 8
Extensibility 9
Summary 9
2. Basics of XMPP ........................................................ 11
Architecture 11
Addresses 14
Domains 15
Users 15
Resources 15
Internationalization 16
XMPP URIs 16
Streaming XML 16
Communication Primitives 18
Message 18
Presence 19
IQ 20
Extensibility 23
Asynchronicity 24
Error Handling 24
Hello Hello World World: Building a Basic XMPP Application 25
Summary 27
v
Part II. The XMPP Toolkit
3. Presence ............................................................. 31
Is Anybody Home? 31
Authorization Required: The Subscription Handshake 31
How Presence Is Propagated 33
Availability Status 35
Presence Priorities 36
Directed Presence 37
Going Offline 37
Rich Presence 38
Presence and Rosters 39
Using Presence 42
Presence-Based Routing 42
Access Control 43
Presence As a Transport 43
Summary 44
4. Instant Messaging ..................................................... 45
I Think, Therefore IM 45
Chat Sessions 47
Are You There? Chat State Notifications 48
Looks Matter: Formatted Messages 52
Who Are You? vCards 53
Talk to the Hand: Blocking and Filtering Communication 55
Blocking: The Simple Approach 55
Advanced Blocking and Filtering 57
More Messaging Extensions 58
Summary 58
5. Discovering the World .................................................. 59
Items and Info 59
Using Service Discovery with Servers and Services 61
Using Service Discovery with Clients 64
Explicit Service Discovery 64
Entity Capabilities: Service Discovery Shorthand 66
Summary 68
6. Data Forms ........................................................... 69
Basic Structure 69
Using Data Forms 71
Defining Your Terms: Form Types 73
vi | Table of Contents
Including Media in Data Forms 74
Summary 75
7. Multi-Party Interactions ................................................ 77
Starting the Party 77
Groupchat Basics 78
Crowd Control 81
What’s in a Nick? 85
Configure This! 87
Privacy, Security, and All That Jazz 91
MUC As a Data Transport 92
Summary 93
8. Publish/Subscribe ...................................................... 95
Why It Matters 95
Quickstart 97
Subscriptions 98
Publishing and Receiving Notifications 100
Payloads: To Send or Not to Send? 102
Items: To Store or Not to Store? 103
Discovering Nodes 104
Node Management 107
Creating and Deleting Nodes 107
Node Configuration 108
Managing Node Access 112
Item Aggregation via Collection Nodes 114
Personal Eventing: PubSub Simplified 117
Summary 122
9. Jingle: Jabber Does Multimedia ......................................... 123
To Instant Messaging and Beyond 123
The Jingle Model 124
Making a Call 127
A Swarm of NATs 131
Jingle on ICE 132
Additional Jingle Actions 135
Summary 136
10. Sending Binary Data ................................................... 137
Starting Small: Bits of Binary 137
Moving On Up: Transferring Midsize Files In-Band 139
Thinking Big: Sending Large Files Out-of-Band 142
Sending Data Directly 142
Table of Contents | vii
Sending Data Through a Proxy 143
Negotiating File Transfer 145
File Transfer Using Stream Initiation 146
Session Negotiation Using Jingle 149
Summary 152
11. Remote Commands ................................................... 153
Controlling Clients 153
A Simple Command 154
Commands and Data Forms 156
Providing Custom Commands 160
Advanced Workflows: SOAP, RPC, IO Data 163
Summary 163
12. Connection Methods and Security ....................................... 165
Negotiating an XMPP Stream 165
Authentication Options 171
Encrypting the Connection 172
Server Federation 174
Server Components 179
BOSH: XMPP over HTTP 180
Serverless Messaging 189
XMPP Security 192
Encryption 193
Authentication and Identity 194
Spam and Abuse 195
Summary 196
Part III. Putting It All Together
13. Design Decisions ...................................................... 199
Is XMPP the Right Choice? 199
How the XMPP Community Works 201
Writing XMPP Software 202
Mixing, Matching, and Extending Existing XMPP Software 202
Client Extension, Bot, Component, or Server Module? 203
Rolling Your Own Client or Server 205
Extending XMPP 207
How to Design Custom Extensions 207
Standardizing New Extensions 209
Summary 210
viii | Table of Contents
14. Building an XMPP Application ........................................... 211
The CheshiR Microblogging Platform 211
First Sprint: The CheshiR XMPP IM Bot 211
Analysis 211
Design 212
Coding 214
Second Sprint: Configuring the CheshiR XMPP IM Bot 216
Analysis 216
Design 216
Coding 217
Third Sprint: Scaling the CheshiR XMPP Service Using a Server Component 218
Analysis 218
Design 219
Coding 220
Fourth Sprint: Registering with the CheshiR Server Component 221
Analysis 221
Design 222
Coding 222
Fifth Sprint: Extending the Server Component with Rosters 224
Analysis 224
Design 224
Coding 224
Future Sprints 227
A CheshiR Server Module or Dedicated Server? 227
Summary 228
Part IV. Appendixes
A. A Guide to XMPP Specifications .......................................... 231
B. Popular Servers, Clients, and Libraries .................................... 253
C. Further Practical Considerations ......................................... 263
Glossary ................................................................... 269
Bibliography ............................................................... 273
Index ..................................................................... 277
Table of Contents | ix