Network Programming Guide Part Number: 800-3850-10 Revision A of 27 March, 1990 Trademarks SunOS™, Sun Workstation®, as well as the word "Sun" followed by a numerical suffix, are trademarks of Sun Microsystems, Incorporated. ONC is a trademark of Sun Microsystems, Incorporated. UNIX® and UNIX System V® are trademarks of Bell Laboratories. All other products or services mentioned in this document are identified by the trademarks or service marks of their respective companies or organizations. Legal Notice to Users The Network Infonnation Service (NIS) was formerly known as Sun Yellow Pages. The functionality of the two remains the same, only the name has changed. The name Yellow Pages™ is a registered trade­ mark in the United Kingdom of British Telecommunications pIc and may not be used without permission. Copyright © 1990 Sun Microsystems, Inc. - Printed in U.S.A. All rights reserved. No part of this work covered by copyright hereon may be reproduced in any fonn or by any means - graphic, electronic, or mechanical - including photocopying, recording, taping, or storage in an information retrieval system, without the prior written permission of the copyright owner. Restricted rights legend: use, duplication, or disclosure by the U.S. government is subject to restrictions set forth in subparagraph (c)(l)(ii) of the Rights in Technical Data and Computer Software clause at DFARS 52.227-7013 and in similar clauses in the FAR and NASA FAR Supplement. The Sun Graphical User Interface was developed by Sun Microsystems, Inc. for its users and licensees. Sun ack­ nowledges the pioneering efforts of Xerox in researching and developing the concept of visual or graphical user inter­ faces for the computer industry. Sun holds a non-exclusive license from Xerox to the Xerox Graphical User Interface, which license also covers Sun's licensees. This product is protected by one or more of the following U.S. patents: 4,777,485 4,688,1904,527,2324,745,407 4,679,0144,435,7924,719,5694,550,368 in addition to foreign patents and applications pending. This software and documentation is based in part on the Fourth Berkeley Software Distribution under license from the Regents of the University of California. We acknowledge the following individuals and institutions for their role in its development: The Regents of the University of California, the Electrical Engineering and Computer Sciences Department at the Berkeley Campus of the University of California, and Other Contributors. Contents Chapter 1 Network Services ............................................................................................. 1 1.1. The Major Network Services .................................................................................... 2 1.2. Network Programming Manual Overview........................................................ 3 1.3. The Network File System (NFS) ............................................................................ 4 Computing Environments ........................................................................................ 5 Example NFS usage .................................................................................................... 6 Example 1: Mounting a Remote Filesystem ............................................ 6 Example 2: Exporting a Filesystem .............................................................. 7 Example 3: Administering a Server Machine ......................................... 8 NFS Architecture .......................................................................................................... 8 Transparent Information Access ............................... ...................................... 8 Different Machines and Operating Systems ............................................ 8 Easily Extensible ..................................................................................................... 8 Ease of Network Administration .................................................................... 9 Reliability .................................................................................................................... 9 High Performance ................................................................................................... 9 The Sun NFS Implementation .......................................................... ,••••• ,:,: ••• "............ The NFS Interface ........................................................................ ,.:" .... ,:,"': ........ :.: .... ,..... .:,',: .... ,.. The NFS and the Mount Protocol ........................ ,... ", ................... ".; ... ,' ..... ;.,; ...... ;-. Pathname Parsing .................................................... ,.~;., ...... ;;;;;;.:.,,;: ................ ,; .... :;;;: ... :;; ... ;••• :::. Export and Mount Lists ...........................................:;;.;.; ...: ..• ,,"'...... ..... ii;; ....:;;:;.;;::; .•••• ; .••.• :....... ;;;::: UNIX Mount Protocol Procedures ......................... 'i ••• " ......... , ...." ....:.· .... i ... " ................... :<:::/ A Stateless Protocol .................................................................... ,:.,. ...................... ;.. ,...... Note: Miscellaneous Network Operations ................................ ;;;.;: ... ;:, .. ;............. - iii- Contents - Continued 1.4. Remote File Sharing (RFS) ....................................................................................... 18 Advertise ............................................................................................... ............................. 18 U nadvertise .......................................................................................... ............................. 18 Remote Mounts .............................................................................................................. 18 Resource Naming .......................................................................................................... 19 RFS Security Features ................................................................................................ 19 Client Authentication ............................................................................................ 19 Client Autllorization .............................................................................................. 19 User and Group Id Mapping ............................................................................. 20 1.5. The Portmapper ................................................................................................................ 21 Port Registration ............................................................................................................ 21 1.6. The Network Infonnation SelVice Database Service .................................. 22 What Is The Network InfOImation Service? ................................................. 23 Network Infonnation Service Maps ................................................................... 23 Network Infonnation Service Domains ........................................................... 23 Masters and Slaves ....................................................................................................... 24 Naming .......................................................................................................................... 24 Data Storage ............................................................................................................... 25 Servers ........................................................................................................................... 25 Clients ............................................................................................................................ 25 Default NIS Files .......................................................................... ................................ 25 Hosts ............................................................................................................................... 26 Passwd ........................................................................................................................... 26 Others ............................................................................................................................. 26 Changing your passwd ......................................................................................... 26 1.7. The Network Lock Manager ..................................................................................... 26 The Locking Protocol ................................................................................................. 29 1.8. The Network Status Monitor .................................................................................... 30 PART ONE: Network Programming .............................................................................. 31 Chapter 2 Introduction to Remote Procedure Calls ........................................ 33 2.1. Overview .............................................................................................................................. 33 How it is useful .............................................................................................................. 33 -iv- Contents - Continued Terrn.inology .................................................................................................................... 33 The RPC Model ............................................................................................................. 34 2.2. Versions and Numbers .................................................................................................