Understanding DCE

Preface. Part I: Components. Chapter 1: DCE: The Network as Computer 1.1 DCE Addresses Many Distributed Computing Issues 1.1.1 DCE Harnesses Latent Computing Power 1.1.2 DCE Increases Availability 1.1.3 DCE Facilitates Collaborative Work and Minimizes Storage Limitations 1.1.4 DCE Services Track Data and Programs that Move Around 1.1.5 DCE Accommodates Heterogeneous Data 1.1.6 DCE Helps You Maintain Distributed Applications 1.1.7 DCE Helps Synchronize Events 1.1.8 DCE Protects Distributed Resources 1.2 DCE Is Based on the Client/Server Model 1.2.1 A General Nondistributed Computing Model 1.2.2 Distributed Computing Models 1.2.3 The Client/Server Computing Model 1.2.4 Client and Server Are Relative Terms 1.2.5 Client/Server Communications 1.3 DCE: A Model for Distribution 1.4 A Look at DCE Application Programming Interfaces 1.5 DCE Is a Good Start 1.5.1 Component Availability 1.5.2 Administration 1.5.3 Documentation 1.5.4 Performance 1.5.5 Support for Object-oriented Programming 1.5.6 Support for Message Queueing 1.5.7 Support for Transaction Processing Applications 1.5.8 Compatibility with Standards 1.5.9 Internationalization 1.6 Who Will Use DCE? 1.7 What Next? Chapter 2: Cells: The Domain of the Distributed Environment 2.1 What Is a Cell? 2.1.1 Purpose 2.1.2 Administration 2.1.3 Security 2.1.4 Overhead 2.2 Each Cell Has a Set of DCE Services 2.2.1 DCE Services Enable Distributed Operation 2.2.2 DCE Software Configurations for Clients and Servers 2.2.3 Some DCE Cell Examples 2.3 Cells and Naming 2.3.1 How Cells Determine Naming Environments 2.3.2 Names Outside of the DCE Directory Service 2.3.3 Summary of Names 2.4 Cell and LAN Profiles Point to DCE Services Chapter 3: Remote Procedure Call: The Foundation of Distributed Computing 3.1 Distribution Builds on the Concept of a Local Application 3.1.1 Local Procedure Call Behavior 3.1.2 Remote Procedure Call Behavior 3.2 The Development Process Enables Distribution 3.3 Interface Definitions Enable Client and Server Interaction 3.4 Binding: How a Client and Server Find Each Other 3.4.1 The Directory Service Identifies Server Hosts 3.4.2 The Endpoint Map Identifies Servers 3.4.3 Server Initialization Lays a Path for Clients 3.4.4 Clients Follow the Path to Servers 3.5 Executing the Remote Procedure Call 3.6 Using, Administering, and Programming RPC Chapter 4: Threads: Improving Program Performance 4.1 What Is DCE Threads? 4.2 Using Threads 4.3 Why Use Threads in an Application? Chapter 5: DCE Security Service: Protecting Resources 5.1 Authentication and Authorization 5.1.1 Passwords Ensure Authenticity 5.1.2 Privilege Attributes Convey Verifiable Identities 5.1.3 Access Control Lists Protect Resources 5.1.4 Special Accounts Enable Intercell Authentication 5.2 The Security Services Resist Tampering 5.2.1 Life Spans Protect Security Information from Illegitimate Use 5.2.2 Frequent Key Substitution Protects Secret Keys 5.2.3 Encryption Ensures Data Authenticity, Privacy, and Integrity 5.2.4 Secure Hosts Protect Security Servers 5.3 Groups and Organizations Simplify Security Management 5.4 How People Interact with the DCE Security Service 5.4.1 Using the DCE Security Service 5.4.2 Administering DCE Security 5.4.3 Administering Access Rights for Applications 5.5 DCE Security in Action 5.6 Programming the DCE Security Service Chapter 6: DCE Directory Service: Locating Resources 6.1 The Directory Service Controls the Naming Environment 6.2 The Naming Environment Maps Names to Resources 6.2.1 CDS Names Correspond to CDS Directories and Object Entries 6.2.2 Distribution Ensures Access to Directories 6.2.3 Child Pointers Link the Name Environment Together 6.2.4 Soft Links Customize a Name Environment 6.2.5 Object Attributes Define Resources 6.2.6 Putting the Parts Together 6.2.7 Update Operations Keep Name Information Current 6.2.8 DCE Security Protects Directory Service Information 6.3 The DCE Directory Service Uses the Client/Server Model 6.3.1 Caching Improves Performance 6.3.2 Clerks Find CDS Servers in Several Ways 6.4 CDS in Action 6.4.1 A Simple Lookup Example 6.4.2 A Complex Lookup Example 6.4.3 A Deeper Look at CDS 6.5 Communicating with a Foreign Cell 6.6 How People Interact with the DCE Directory Service 6.6.1 Using the DCE Directory Service 6.6.2 Administering the DCE Directory Service 6.6.3 Programming with the DCE Directory Service Chapter 7: DCE Time Service: Synchronizing Network Time 7.1 How Does DTS Work? 7.2 DTS Time Is Cellwide 7.3 Synchronizing Cell Time with External Time Sources 7.4 Using DTS 7.5 Administering DTS 7.6 Programming with DTS Chapter 8: DCE Distributed File Service: Providing Cellwide Access to Files 8.1 Some Good Reasons to Use DFS 8.2 DFS Is a Comprehensive File System 8.2.1 The DCE Local File System can Coexist with a Host's Native File System 8.2.2 DFS Acts on Groups of Files Called Filesets 8.2.3 DFS Tracks Files as They Move 8.2.4 DFS Locates and Backs Up Filesets 8.2.5 DFS Protects Files Using DCE Access Control Lists 8.2.6 DFS Protects Its Servers by Using DFS Distributed Security 8.2.7 DFS Ensures Server Software Consistency 8.2.8 DFS Simplifies Management Using Administrative Domains 8.2.9 DFS Clients Use Caching to Speed Operations 8.2.10 DFS Clients Can Include Diskless Workstations 8.3 How DFS Works 8.4 DFS Files Connect to the Larger World 8.5 How People Interact with the DCE Distributed File Service 8.5.1 Using the DCE Distributed File Service 8.5.2 Administering the DCE Distributed File Service 8.5.3 Writing Programs that Use DFS Programming Interfaces Part II: Configuration and Management Considerations Chapter 9: A Look at Writing DCE Applications 9.1 Designing Your Client/Server Application 9.1.1 Developing a Comprehensive User Model Is Critical 9.1.2 What is the job and how will your application facilitate work flow? 9.1.3 What resources do you require and where are the resources located? 9.1.4 How can you connect groups of people effectively with the resources they need to do their jobs? 9.1.5 A Client/Server Application Is a Series of Related Mini-applications 9.1.6 Take Cell Configuration and Network Topology into Consideration 9.1.7 The Level of Security Is Up to You 9.1.8 A Well-designed Interface Aids Scalability and Maintainability 9.1.9 Threads Present New Challenges to Application Designers 9.2 Implementing Your Client/Server Application 9.2.1 Coding Your First DCE Client/Server Application 9.2.2 Creating a Production-ready Application 9.2.3 Distributing Existing Code 9.3 DCE Programming-language Considerations 9.4 What Next? Chapter 10: Getting Started with DCE 10.1 Low Impact on Physical Network Components 10.2 Low Impact on Non-DCE Users 10.3 You Can Choose Your Own Pace 10.4 DCE Implementations Permit Planning in Stages 10.5 DCE Is Dynamic 10.6 Where We'll Go from Here Chapter 11: Determining Your Cell's Boundaries 11.1 Factors that Influence the Boundaries of a Cell 11.2 For Whom the Cell Tolls-And Why? 11.3 What Are Your Security Requirements? 11.3.1 Authentication Across Cells 11.3.2 Repairing a Breach of Your Cell's Security 11.4 What Are Your Projected Administrative Requirements? 11.5 How Will DCE Affect Computing and Network Overhead? Chapter 12: Initial Cell Configuration Guidelines 12.1 Choosing a Name for Your Cell 12.1.1 GDS or DNS?-You've Got to Pick One 12.1.2 Cell Names are Difficult to Change 12.1.3 The Cell Name You Choose Must Be Unique Within Your Organization 12.1.4 Get In-House Approval for Your Cell Name Before You Register 12.1.5 Caveats for Naming Isolated Cells 12.2 Configuring DCE Server and Client Systems 12.2.1 Reasons to Configure DCE Core Services on One System 12.2.2 Reasons to Disperse DCE Core Services from the Start 12.2.3 Configuring Client-Only Systems 12.2.4 Configuring DFS 12.2.5 Configuring GDS Chapter 13: Setting Up Security in a New Cell 13.1 Default Access Controls Created by Cell Initialization 13.1.1 The cell_admin Principal Has Unlimited Access to Everything 13.1.2 DCE Authorization Groups Get Control of Specific Services 13.1.3 Initial Access Controls on DCE Core Services 13.1.4 Initial Access Controls on DFS 13.1.5 Initial Access Controls on GDS 13.1.6 Summary 13.2 Modifying Default Security Policies of DCE Services 13.3 Three Example Security Scenarios 13.3.1 Scenario One: Low Security 13.3.2 Scenario Two: Medium Security 13.3.3 Scenario Three: Clamping Your Cell Shut 13.4 A Little Friendly ACL Advice 13.4.1 How Secure is Secure Enough? Chapter 14: Distributing and Replicating Core DCE Services 14.1 Distributing the Cell Directory Service 14.1.1 Where Should You Locate Your CDS Servers? 14.2 Distributing the Security Service 14.3 Distributing the Time Service Part III: Appendices Appendix A: DCE Client/Server Examples A.1 Bare-Bones Client Code A.2 A Simple Threaded Version of the Application A.3 A Bare-Bones Application with Authentication A.4 The Application with Error Checking, Mutexes, and Server-Group Registration A.5 A Sample Make File Appendix B: Common DCE Questions...and Some Answers B.1 I was just wondering... B.2 I'm a system administrator, and I was wondering... B.3 I'm an application programmer, and I have a friend who was just wondering... Appendix C: External Time Providers and Services C.1 Sources of Coordinated Universal Time C.1.1 Telephone Services C.1.2 Radio Broadcasts C.1.3 Satellites C.2 Time Source Pricing Appendix D: Registering a Name: GDS and DNS D.1 Obtaining a Unique GDS Cell Name D.2 Obtaining a Unique DNS Cell Name Figures Chapter 1: DCE: The Network as Computer 1-1 Nondistributed computing model 1-2 Simple models of distribution 1-3 Distribution within an application component 1-4 Typical client/server application 1-5 A host can be a client and a server 1-6 DCE application programming interfaces 1-7 A distributed application uses DCE APIs Chapter 2: Cells: The Domain of the Distributed Environment 2-1 Distributed operation in a DCE cell 2-2 DCE client and server software 2-3 A simple DCE cell 2-4 Cell with DCE DFS and multiple DCE client hosts 2-5 Cell and global naming environments 2-6 Interaction of CDS and a GDA Chapter 3: Remote Procedure Call: The Foundation of Distributed Computing 3-1 A nondistributed application conceptual model 3-2 A distributed application conceptual model 3-3 Interface definition development steps 3-4 Distributed application development tasks 3-5 Simplified server initialization 3-6 Finding a server 3-7 Completing a remote procedure call. Chapter 4: Threads: Improving Program Performance 4-1 Nonthreaded applications execute serially 4-2 Threaded applications execute concurrently 4-3 Locking shared data Chapter 5: DCE Security Service: Protecting Resources 5-1 Authentication in a foreign cell 5-2 General tasks in a secure environment Chapter 6: DCE Directory Service: Locating Resources 6-1 Parts of a CDS server 6-2 Physical views of a cell's name environment 6-3 A simple CDS lookup 6-4 A complex CDS lookup 6-5 The CDS lookup process Chapter 7: DCE Time Service: Synchronizing Network Time 7-1 Computing time from intersecting time intervals 7-2 A global server helps synchronize a multi-LAN cell Chapter 8: DCE Distributed File Service:Providing Cellwide Access to Files 8-1 Simple DFS file operation 8-2 DFS file names are globally unique Chapter 9: A Look at Writing DCE Applications 9-1 Traditional designs: the application task and geography remain constant 9-2 Client/server designs: the user model and threads play a large role 9-3 A simple client/server configuration 9-4 Determine which user groups need which resources 9-5 A user model is the definition of all client/server relationships 9-6 Consider network topology when distributing code 9-7 A poorly designed interface hampers security performance 9-8 Well-designed interfaces improve security performance 9-9 Client/server implementations and their interface 9-10 A server creates threads to handle client requests 9-11 A client's use of threaded routines 9-12 What the sample application does Examples Appendix A: DCE Client/Server Examples A-1 Client code prototype: fetch_string_basic.c A-2 The interface file: hello_world.idl A-3 Threaded client code: fetch_string.c A-4 Nonreentrant remote procedure: get_hello_world.c A-5 Single-threaded server initialization code: hw_server_init.c A-6 ACF file for Security: hello_world_security.acf A-7 Client code with security: fetch_string_security.c A-8 Authentication in the server initialization code: hw_server_init_security.c A-9 Complete client code: get_hello_world_complete A-10 Complete client code: fetch_string_complete.c A-11 Multithreaded server's initialiation file: hw_server_init_complete.c A-12 Error-checking code: check_status.h A-13 Sample Make File Tables Appendix A: DCE Client/Server Examples A-1 Sample Programs Appendix C: External Time Providers and Services C-1 UTC Radio Stations and Managing Authorities C-2 Radio Receiver Manufacturers C-3 Time-Provider Selection Criteria