User’s Guide 0890428-010 February 1997 Copyright 1997 by Concurrent Computer Corporation. All rights reserved. This publication or any part thereof is intended for use with Concurrent products by Concurrent Computer Corporation personnel, customers, and end– users. It may not be reproduced in any form without the written permission of the publisher. The information contained in this document is believed to be correct at the time of publication. It is subject to change without notice. Concurrent Computer Corporation makes no warranties, expressed or implied, concerning the infor- mation contained in this document. To report an error or comment on a specific portion of the manual, photocopy the page in question and mark the cor- rection or comment on the copy. Mail the copy (and any additional comments) to Concurrent Computer Corporation 2101 W. Cypress Creek Road, Ft. Lauderdale, FL 33309–1892. Mark the envelope “Attention: Publications Department.” This publication may not be reproduced for any other reason in any form without written permission of the publisher. UNIX is a registered trademark, licensed exclusively by X/Open Company Ltd. Printed in U. S. A. Revision History: Level: Effective With: Original Release -- July 28, 1994 000 PowerUX 1.1 Reissue 1 -- February 1997 010 PowerMAX OS 4.1 Contents Contents Chapter 1 Introduction Introduction . 1-1 Contents of this Guide . 1-1 Secure Facility User's Guide . 1-1 System Overview . 1-2 UNIX System Tutorials. 1-2 Reference Information. 1-3 Syntax Notation . 1-4 Referenced Documentation . 1-5 Chapter 2 What Is the UNIX System? Overview of the UNIX Operating System. 2-1 The Kernel . 2-2 UNIX System Commands . 2-3 Command Functions . 2-4 Executing Commands . 2-4 The File System . 2-6 Ordinary Files . 2-7 Directories . 2-7 Special Files . 2-8 Symbolic Links . 2-8 System Layout. 2-8 Security Concepts . 2-10 System Security Officer . 2-10 Protecting Information . 2-10 Basic Security. 2-11 Enhanced Security . 2-11 Security Policy. 2-13 Subjects, Objects, and Access Types . 2-13 Discretionary Access Control (DAC). 2-14 Basic ACL Entries. 2-15 ACL Generation for Files . 2-16 DAC Access Check Algorithm . 2-18 Mandatory Access Control (MAC) . 2-19 MAC Concepts and Definitions . 2-19 MAC Access Rules . 2-20 Rules for Objects . 2-20 Establishing the Levels of Objects and Subjects . 2-21 The Kernel, Access Control, and Security. 2-21 User Level . 2-24 System Calls . 2-25 Processes. 2-25 Interprocess Communication (IPC). 2-27 Signals . 2-28 iii User’s Guide Chapter 3 Basics for UNIX System Users Introduction . 3-1 The Terminal . 3-1 Required Terminal Settings. 3-2 Keyboard Characteristics . 3-2 Typing Conventions . 3-3 The Command Prompt. 3-4 Correcting Typing Errors. 3-4 Deleting the Current Line: The @ Sign . 3-4 Deleting Last Characters Typed: <CTRL><h> & <BACKSPACE> 3-5 Reassigning the Delete Functions . 3-5 Using Special Characters as Literal Characters. 3-6 Typing Speed . 3-6 Stopping Commands . 3-6 Using Control Characters . 3-7 Obtaining a Login Name . 3-7 Communicating with the UNIX System . 3-8 Getting a Login Prompt with the Secure Attention Key. 3-9 Login Procedure . 3-10 Problems When Logging In . 3-14 Simple Commands . 3-15 Logging Off . 3-16 Chapter 4 Using the File System Introduction . 4-1 File System Structure . 4-1 Your Place in the File System . 4-3 Home Directory . 4-3 Current Directory . 4-4 Pathnames . 4-5 Full Pathnames. 4-5 Relative Pathnames . 4-7 Directory and File Names . 4-10 Security and Files. 4-11 Organizing a Directory. ..