Contents
Foreword
Preface
Chapter 1 Introduction And Overview
1.1 Use Of TCP/IP
1.2 Designing Applications For A Distributed Environment
1.3 Standard And Nonstandard Application Protocol Use
1.4 An Example Of Standard Application Protocol Use
1.5 An Example Connection
1.6 Using TELNET To Access An Alternative Service
1.7 Application Protocols And Software Flexibility
1.8 Viewing Services From The Provider's Perspective
1.9 The Remainder Of This Text
1.10 Summary
Chapter 2 The Client Server Model And Software Design
2.1 Introduction
2.2 Motivation
2.3 Terminology And Concepts
2.3.1 Clients And Servers
2.3.2 Privilege And Complexity
2.3.3 Standard Vs.Nonstandard Client Software
2.3.4 Parameterization Of Clients
2.3.5 Connectionless Vs.Connection-Oriented Servers
2.3.6 Stateless Vs.Stateful Servers
2.3.7 A Stateful File Server Example
2.3.8 Statelessness Is A Protocol issue
2.3.9 Severs As Clients
2.4 Summary
Chapter 3 Concurrent Processing In Client-Server Software
3.1 Introduction
3.2 Concurrency In Networks
3.3 Concurrency In Servers
3.4 Terminology And Concepts
3.4.1 the Process concept
3.4.2 Threads
3.4.3 Programs vs.Threads
3.4.4 Procedure Calls
3.5 An Example Of Concurrent Process Creation
3.5.1 A Sequential C Example
3.5.2 A Concurrent Version
3.5.3 Timeslicing
3.6 Executing New Code
3.7 Context Switching And Protocol Software Design
3.8 Concurrency And Asynchronous I /O
3.9 Summary
Chapter 4 Program Interface To Protocols
4.1 Introduction
4.2 Loosely Specified Protocol Software Interface
4.2.1 Advantages And Disadvantages
4.3 Interface Functionality
4.4 Conceptual Interface Specification
4.5 System Calls
4.6 Two Basic Approaches To Network Communication
4.7 The Basic I/O Functions Available In UNIX
4.8 Using UNIX I/O With TCP/IP
4.9 Summary
Chapter 5 The Socket Interface
5.1 Introduction
5.2 Berkeley Sockets
5.3 Specifying A Protocol Interface
5.4 The Socket Abstraction
5.4.1 Socket Descriptors
5.4.2 System Data Structures For Sockets
5.4.3 Using Sockets
5.5 Specifying An Endpoint Address
5.6 A Generic Address Structure
5.7 Major System Calls Used With Sockets
5.7.1 The WSAStartup Function
5.7.2 The WSACleanup Function
5.7.3 The Socket Function
5.7.4 The Connect Function
5.7.5 The Send Function
5.7.6 The Recv Function
5.7.7 The Closescket Function
5.7.8 The Bind Function
5.7.9 The Listen unction
5.7.10 The Accept Function
5.7.11 Summary Of Socket Calls Used With TCP
5.8 Utility Routines For Integer Conversion
5.9 Using Socket Calls In A Program
5.10 Symbolic Constants For Socket Call Parameters
5.11 Summary
Chapter 6 Algorithms And Issues In Client Software Design
6.1 Introduction
6.2 Learning Algorithms Instead Of Details
6.3 Client Architecture
6.4 Identifying The Location Of A Server
6.5 Parsing An Address Argument
6.6 Looking Up A Domain Name
6.7 Looking Up A Well-Known Port By Name
6.8 Port Numbers And Network Byte Order
6.9 Looking Up A Protocol By Name
6.10 The TCP Client Algorithm
6.11 Allocating A Socket
6.12 Choosing A Local Protocol Port Number
6.13 A Fundamental Problem In Choosing A Local IP Address
6.14 Connecting A TCP Socket To A Server
6.15 Communicating With The Server Using TCP
6.16 Reading A Response From A TCP Connection
6.17 Closing A TCP Connection
6.17.1 The Need For Partial Close
6.17.2 A Partial Close Operation
6.18 Programming A UDP Client
6.19 Connected And Unconnected UDP Sockets
6.20 Using Connect With UDP
6.21 Communicating With A Server Using UDP
6.22 Closing A Socket That Uses UDP
6.23 Partial Close For UDP
6.24 A Warning About UDP Unreliability
6.25 Summary
Chapter 7 Example Client Software
7.1 Introduction
7.2 The Importance Of Small Examples
7.3 Hiding Details
7.4 An Example Procedure Library For Client Programs
7.5 Implementation Of ConnectTCP
7.6 Implementation Of connected
7.7 A Procedure That Forms Connections
7.8 Using The Example Library
7.9 The DAYTIME Service
7.10 Implementation Of A TCP Client For DAYTIME
7.11 Reading From A TCP Client For DAYTIME
7.12 The TIME Service
7.13 Accessing The TIME Service
7.14 Accurate Times And Network Delays
7.15 A UDP Client For The TIME Service
7.16 The ECHO Service
7.17 A TCP Client For The ECHO Service
7.18 A TCP Client For The ECHO Service
7.19 Summary
Chapter 8 Algorithms And Lssues In Server Software Design
8.1 Introduction
8.2 The Conceptual Server Algorithm
8.3 Concurrent Vs.Iterative Servers
8.4 Connection-Oriented Vs.Connectionless Access
8.5 Connection-Oriented Servers
8.6 Connectionless Servers
8.7 Failure,Reliability,And Statelessness
8.8 Optimizing Stateless Servers
8.9 Four Basic Types Of Servers
8.10 Request Processing Time
8.11 Iterative Server Algorithms
8.12 An Iterative,Connection-Oriented Server Algorithm
8.13 Binding To A Well-Known Address Using INADDR-ANY
8.14 Placing The Socket In Passive Mode
8.15 Acceptin Connections And Using Them
8.16 An Iterative,Connectionless Server Algorithm
8.17 Forming A Reply Address In A Connectionless Server
8.18 Concurrent Server Algorithms
8.19 Master And Slave Processes
8.20 A Concurrent,Connectionless Server Algorithm
8.21 A Concurrent,Connection-Oriented Server Algorithm
8.22 Using Separate Programs As Slaves
8.23 Apparent Concurrency Using A Single Process
8.24 When To Use Each Server Type
8.25 A Summary of Server Types
8.26 The Important Problem Of Server Deadlock
8.27 Alternative Implementations
8.28 Summary
Chapter 9 Iterative,Connectionless Servers(UDP)
9.1 Introduction
9.2 Creating A Passive Socket
9.3 Process Structure
9.4 An Example TIME Server
9.5 Summary
Chapter 10 Iterative,Connection-Oriented Servers(TCP)
10.1 Introduction
10.2 Allocating A Passive TCP Socket
10.3 A Server For The DAYTIME Service
10.4 Process Structure
10.5 An Example DAYTIME Server
10.6 Closing Connections
10.7 Connection Termination And Server Vulnerability
10.8 Summary
Chapter 11 Concurrent ,Connection-Oriented Servers(TCP)
11.1 Introduction
11.2 Concurrent ECHO
11.3 Iterative Vs.Concurrent Implementations
11.4 Process Structure
11.5 An Example Concurrent ECHO Server
11.6 Cleaning Up Errant Processes
11.7 Summary
Chapter 12 Single--Process,Concurrent Servers(TCP)
12.1 Introduction
12.2 Data-driven Processing In A Server
12.3 Data-DrivenProcessing With A Single Process
12.4 Process Structure Of A Single-Process Server
12.5 An Example Single-Process ECHO Server
12.6 Summary
Chapter 13 Multiprotocol Servers(TCP,UDP)
13.1 Introduction
13.2 The Motivation For Reducing The Number Of Servers
13.3 Multiprotocol Server Design
13.4 Process Structure
13.5 An Example Multiprotocol DAYTIME Server
13.6 The Concept Of Shared Code
13.7 Concurrent Multiprotocol Servers
13.8 Summary
Chapter 14 Mulitiservice Servers(TCP,UDP)
14.1 Introduction
14.2 Consolidation Servers
14.3 A Connectionless,Multiservice Server Design
14.4 A Connection-Oriented,Multiservice Server Design
14.5 A Concurrent,Connection-Oriented,Multiservice Server
14.6 A Single-Process,Multiservice Server Implementation
14.7 Invoking Separate Programs From A Multiservice Server
14.8 Multiservice,Multiprotocol Designs
14.9 An Example Multiservice Server
14.10 Static and Dynamic Server Configuration
14.11 The UNIX Super Server,Inetd
14.12 An Example Inetd Server
14.13 Summary
Chapter 15 Uniform,Efficient Management Of Server Concurrency
15.1 Introduction
15.2 Choosing Between An Iterative And A Concurrent Design
15.3 Level Of Concurrency
15.4 Demand-Driven Concurrency
15.5 The Cost Of Concurrency
15.6 Overhead And Delay
15.7 Small Delays Can Matter
15.8 Process Percolation
15.8.1 Percolation Techniques
15.8.2 Percolation In A Connection-Oriented Server
15.8.3 Percolation In A Connectionless Server
15.8.4 Percolation Burst Traffic ,And NFS
18.8.5 Preallocation On A Multiprocessor
15.9 Delayed Process Allocation
15.10 The Uniform Basis For Both Techniques
15.11 Combining Techniques
15.12 Summary
Chapter 16 Concurrency In Clients
16.1 Introduction
16.2 The Advantages Of Concurrency
16.3 The Motivation For Exercising Control
16.4 Concurrent Contact With Multiple Servers
16.5 Implementing Concurrent Clients
16.6 Single-Process Implementations
16.7 An Example Concurrent Client That Uses ECHO
16.8 Execution Of The Concurrent Client
16.9 Concurrency In The Example Code
16.10 Summary
Chapter 17 Tunneling At The Transport And Application Levels
17.1 Introduction
17.2 Multiprotocol Environments
17.3 Mixing Network Technologies
17.4 Dynamic Circuit Allocation
17.5 Encapsulation And Tunneling
17.6 Tunneling Through An IP Internet
17.7 Application-Level Tunneling Between Clients And Servers
17.8 Tunneling,Encapsulation,And Dialup Phone Lines
17.9 Summary
Chapter 18 Application Level Gateways
18.1 Introduction
18.2 Clients And Servers In Constrained Environments
18.2.1 The Reality Of Multiple Technologies
18.2.2 Computers With Limited Functionality
18.2.3 Connectivity ConstraintsThat Aries From Security
18.3 Using Application Gateways
18.4 Interoperability Through A Mail Gateway
18.5 Implementation Of A Mail Gateway
18.6 A Comparison Of Application Gateways And Tunneling
18.7 Application Gateways And Limited Functionality Systems
18.8 Application Gateways Used For Security
18.9 Application Gateways And The Extra Hop Problem
18.10 An Example Application Gateway
18.11 Implementation Of An Application Gateway
18.12 Code For The Application Gateway
18.13 An Example Gateway Exchange
18.14 Using RFD With UNIX's forward
18.15 A General-Purpose Application Gateway
18.16 Operation Of SLURP
18.17 How SLURP Handles Connections
18.18 IP A dressing And SLURP
18.19 Summary
Chapter 19 External Data Representation(XDR)
19.1 Introduction
19.2 Representations For Data In Computers
19.3 The N-Squared Conversion Problem
19.4 Network Standard Byte Order
19.5 A De Facto Standard External Data Representation
19.6 XDR Data Types
19.7 Implicit Types
19.8 Software Support For Using XDR
19.9 XDR Library Routines
19.10 Building A Message One Piece At A Time
19.11 Conversion Routines In The XDR Library
19.12 XDR Streams,I/O,and TCP
19.13 Records,Record Boundaries,And Datagram I/O
19.14 Summary
Chapter 20 Remote Procedure Call Concept(RPC)
20.1 Introduction
20.2 Remote Procedure Call Model
20.3 Two Paradigms For Building Distributed Programs
20.4 A Conceptual Model For Conventional Procedure Calls
20.5 An Extension Of the Procedural Model
20.6 Execution Of Conventional Procedure Call And Return
20.7 The Procedural Model In Distributed Systems
20.8 Analogy Between Client-Server And RPC
20.9 Distributed Computation As A Program
20.10 Sun Microsystems'Remote Procedure Call Defamation
20.11 Remote Programs And Procedures
20.12 Reducing The Number Of Arguments
20.13 Identifying Remote programs And Procedures
20.14 Accommodation Multiple Versions Of A Remote Program
20.15 Mutual Exclusion For Procedures In A Remote Program
20.16 Communication Semantics
20.17 At Least Once Semantics
20.18 RPC Retransmission
20.19 Mapping A Remote Program To A Remote Procedure
20.20 Dynamic Port Mapping
20.21 RPC Port Mapped Algorithm
20.22 RPC Message Format
20.23 Marshaling Arguments For A Remote Procedure
20.24 Authentication
20.25 An Example Of RPC Message Representation
20.26 An Example Of The UNIX Authentication Field
20.27 Summary
Chapter 21 Distributed Program Generation(Rpcgen Concept)
21.1 Introduction
21.2 Using Rremote Procedure Calls
21.3 Programming Mechanisms To Support RPC
21.4 Dividing A Program Into Local And Remote Procedures
21.5 Adding Code For RPC
21.6 Stub Procedures
21.7 Multiple Remote Procedures And Dispatching
21.8 Name Of The Client-Side Stub Procedure
21.9 Using Rpcgen To Generate Distributed Programs
21.10 Rpcgen Output And Interface Procedures
21.11 Rpcgen Input And Interface Procedures
21.12 Using Remote To Build A Client And Server
21.13 Summary
Chapter 22 Distributed Program Generation (Rpcgen EXAMPLE)
22.1 Introduction
22.2 An Example To Illustrate Rpcgen
22.3 Dictionary Look Up
22.4 Eight Steps To A Distributed Application
22.5 Step 1 :Build A Conventional Application Program
22.6 Step 1:Dived The Program Into Two Parts
22.7 Step 2:Create An Rrpcgen Specification
22.8 Step 4:Run Rpcgen
22.9 The .h File Produced By Rpcgen
22.10 The XDR Conversion File Produced By Rpcgen
22.11 The Client Code Produced By Rpcgen
22.12 The Server Code Produced By Rpcgen
22.13 Step 5:Write Stub Interface Procedures
22.13.1 Client-Side Interface Routines
22.13.2 Server-Side Interface Routines
22.14 Step 6:Compile And Link The Client Program
22.15 Step 7:Compile And Link The Server Program
22.16 Step 8:Start The Link The Server Program
22.17 Using The UNIX Make Utility
22.18 Summary
Chapter 23 Network File System Concepts(NFS)
23.1 Introduction
23.2 Remote File Access Vs.Transfer
23.3 Operations On Remote FILES
23.4 File Access Among Heterogeneous Computers
23.5 Stateless Servers
23.6 NFS And UNIX File Semantics
23.7 Review Of The UNIX File System
23.7.1 Basic Definitions
23.7.2 A Byte Sequence Without Record Boundaries
23.7.3 A File's Owner And Group Identifiers
23.7.4 Protection And Access
23.7.5 The UNIX Open-Read-Write-Close Paradigm
23.7.6 UNIX Data Transfer
23.7.7 Permission To Search A Directory
23.7.8 UNIX Random Access
23.7.9 Seeking Beyond The End Of A UNIX File
23.7.10 UNIX File Position And Concurrent Access
23.7.11 Semantics Of Write During Concurrent Access
23.7.12 UNIX File Names And Paths
23.7.13 The UNIX Inode:Information Stored With A File
23.7.14 The UNIX Stat Operation
23.7.15 The UNIX File Naming Mechanism
23.7.16 UNIX File System Mounts
23.7.17 UNIX File Name Resolution
23.7.18 UNIX Symbolic Links
23.8 Files Under NFS
23.9 NFS File Types
23.10 NFS File Modes
23.11 NFS File Attributes
23.12 NFS Client And Server
23.13 NFS Client Operation
23.14 NFS Client And UNIX
23.15 NFS Mounts
23.16 File Handle
23.17 Handles Replace Path Names
23.18 An NFS Client In UNIX
23.19 File Positioning With A Stateless Server
23.20 Operations On Directories
23.21 Reading A Directory Statelessly
23.22 Multiple Hierarchies In An NFS Server
23.23 The Mount Protocol
23.24 Summery
Chapter d24 Network File System protocol(NFS,Mount)
24.1 Introduction
24.2 Using RPC To Define A Protocol
24.3 Defining A Protocol With Data Structures And Procedures
24.4 NFS Constant,Type ,And Data Declarations
24.4.1 NFS Constants
24.4.2 NFS Typedef Declarations
24.4.3 NFS Data Structures
24.5 NFS Procedures
24.6 Semantics Of NFS Operations
24.6.1 NFSPROC_NULL
24.6.2 NFSPROC_GETATTR
24.6.3 NFSPROC_SETATTR
24.6.4 NFSPROC_ROOT
24.6.5 NFSPROC_LOOKUP
24.6.6 NFSPROC_READLINK
24.6.7 NFSPROC_READ
24.6.8 NFSPROC_WRITECACHE
24.6.9 NFSPROC_WRITE
24.6.10 NFSPROC_CREATE
24.6.11 NFSPROC_REMOVE
24.6.12 NFSPROC_RENAME
24.6.13 NFSPROC_LINK
24.6.14 NFSPROC_SYMLINK
24.6.15 NFSPROC_MKDIR
24.6.16 NFSPROC_RMDIR
24.6.17 NFSPROC_READDIR
24.6.18 NFSPROC_STATFS
24.7 The Mount Protocol
24.7.1 Mount constant Definitions
27.4.2 Mount Type Definitions
27.7.3 Mount Data Structures
24.8 Procedures In The Mount Protocol
24.9 Semantics of Mount Operations
24.9.1 MNTPROC_NULL
24.9.2 MNTPROC_MNT
24.9.3 MNTPROC_DUMP
24.9.4 MNTPROC_UMNT
24.9.5 MNTPROC_UMNTALL
24.9.6 MNTPROC_EXPORT
24.10 NFS And Mount Authentication
24.11 Changes In NFS Version 3
24.12 Summary
Chapter 25 A TELNET Client (Program Structure)
25.1 Introduction
25.2 Overview
25.2.1 The User's terminal
25.2.2 Command And Control Information
25.2.3 Terminals,Windows ,and Files
25.2.4 The Need for Concurrency
25.2.5 A Thread Modest For A TELNET Client
25.3 A TELNET Client Algorithm
25.4 Terminal I/O In UNIX
25.5 Establishing Terminal Modes
25.6 Global Variable Used For Stored State
25.7 Restoring Terminal Modes Before Exit
25.8 Client Suspension And Resumption
25.9 Finite State Machine Specification
25.10 Embedding Commands In A TELNET Data Stream
25.11 Option Negotiation
25.12 Request/Offer Symmetry
25.13 TELNET Character Definitions
25.14 A Finite State Machine For Data From The Server
25.15 Transitions Among States
25.16 A Finite State Machine Implementation
25.17 A Compact FSM Representation
25.18 Keeping The Compact Representatin At Run-Time
25.19 Implementation Of A Compact Representation
25.20 Building An FSM Transition Machine
25.21 The Socket Output Finite State Machine
25.22 Definitions For The Socket Output FSM
25.23 The Option Subnegotiation Finite State Machine
25.24 Definitions For The Option Subnegotiation FSM
25.25 FSM Initialization
25.26 Arguments For The TELNET Client
25.27 The Heart Of The TELNET Client
25.28 Implementation Of The Main FSM
25.29 Summary
Chapter 26 A TELNET Client (Implementation Details)
26.1 Introduction
26.2 The FSM Action Procedures
26.3 Recording The Type Of An Option Request
26.4 Performing No Operation
26.5 Responding To WILL/WONT For The Echo Option
26.6 Responding To WILL/WONT For Unsupported Options
26.7 Responding To WILL/WONT For The No Go-Ahead Option
26.8 Generating DO/DONT For Binary Transmission
26.9 Responding To DO/DONT For Unsupported Options
26.10 Responding To DO/DONT For Transmit Binary Option
26.11 Responding To DO/DONT For The Terminal Type Option
26.12 Option Subnegotiation
26.13 Sending Terminal Type Information
26.14 Terminating Subnegotiation
26.15 Sending A Character To The Server
26.16 Displaying Incoming Data On The User's Terminal
26.17 Using Tarmac To Control The User's Terminal
26.18 Writing A Block Of Data To The Server
26.19 Interacting With The Client Process
26.20 Responding To Illegal Commands
26.21 Scripting To A File
26.22 Implementation Of Scripting
26.23 Initialization Of Scripting
26.24 Collecting Characters Of The Script File Name
26.25 Opening A Script File
26.26 Terminating Scripting
26.27 Pruning Status Information
26.28 Summary
Chapter 27 Practical Hints And Techniques For UNIX Servers
27.1 Introduction
27.2 Operation In Gakground
27.3 Progranuning A Server To Operate In Background
27.4 Open Descriptors And Inheritance
27.5 Programming A Server To Close Inherited Descriptors
27.6 Signals From The Controlling TTY
27.7 Programming A Server To Change Its Controlling TTY
27.1 Generation Log Messages
27.8 Moving To A Safe And Known Directory
27.9 Programming A Server To Change Directories
27.10 The UNIX Unmask
27.11 Programming A Server To Set Its Unmask
27.12 Process Groups
27.13 Programming A Server To Set Its Pooches Group
27.14 Descriptors For Standard I/O
27.15 Programming A Server To Open Standard Descriptors
27.16 Mutual Exclusion For The Server
27.17 Programming A Server To Avoid Multiple Copies
27.18 Recording A Server's Process ID
27.19 Programming A Server To Record Its Process ID
27.20 Waiting For A Child Process To Exit
27.21 Programming A Server To Wait For Each Child To Exit
27.22 Extremes Sigma's
27.23 Programming A Server To Ignore Extremes Signals
27.24 Using A System Log Facility
27.25 Summary
Chapter 28 Deadlock And Starvation In Client-Server Systems
28.1 Introduction
28.2 Definition Of Deadlock
28.3 Difficulty Of Deadlock Detection
28.4 Deadlock Avoidance
28.5 Deadlock Between A Client And Server
28.6 Avoiding Deadlock In A Single Interaction
28.7 Starvation Among A Set Of Clients And A Server
28.8 Busy Connections And Starvation
28.9 Avoiding Blocking Operations
28.10 Processes,Connections,And Other Limits
28.11 Cycles Of Clients And Servers
28.12 Documenting Dependencies
28.13 Summary
Appendix 1 System Calls And Library Routines Used With Sockets
Appendix 2 Manipulation Of UNIX File And Socket Descriptors
Bibliography
Index