內容介紹
內容簡介TCP/IP網路互連技術系列的第Ⅲ卷討論客戶/服
務器編程和套用，講述了構築所有分散式計算系統的客
戶/伺服器計算模型的基本慨念，內容涉及各種不同的
伺服器設計方法，以及用來構造客戶/伺服器的各種工具
和技術，包括遠程過程調用RPC。書中包含了用來說明
每種設計和工具的運行程式示例的原始碼。卷Ⅲ有三個
版本：BSD套接字版，AT&TTLI版，WindowsSockets
版。本書系WindowsSockets版，討論在Internet上
套用軟體通過TCP/IP進行通信的問題，適用於Windows
95，Wind0wSNT，Win32環境下編程和使用Windows
SocketAPI套用編程接口。
作品目錄
ContentsForeword
Preface
Chapter 1 Introduction And Overview
1.1 Use OfTCP/IP
1.2 Designing Applications For A Distributed Environment
1.3 Standard And Nonstandard Application Protocols
1.4 An Example Of Standard Application Protocol Use
1.5 An Example Connection
1.6 Using TELNET To Access An Altemative Service
1.7 Application Protocols And Software Flexibility
1.8 Viewing Services From The Provider's Perspeclive
1.9 The Remainder Of The Text
1.10 Summary
Chapter 2 The Client Server Model And Software Design
2.1 Introduction
2.2 Molivation
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 Pardmeterization 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 Servers 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 Thread Creation
3.5.1 A Sequential C Example
3.5.2 A Concurrent Version
3.5.3 Timeslicing
3.6 Diverging Threads
3.7 Context Switching And Protocol Software Design
3.8 Concurrency And Asynchronous 1/o
3.9 Concurrency Under UNIX
3.10 Execuling A Separately Compiled Program
3.11 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 Conceptua! Interface Speclfication
4.5 Implementation Of An APl
4.6 Two Basic Approaches To Network Communicatwn
4.7 The Basic 1/0 Functions Available In ANSI C
4.8 Hislory Of The UNIX Socket APl
4.9 Summary
Chapter 5 TheSocketAPI
5.1 Introduction
5.2 The History Of Sockets
5.3 Speifving A Protocol Interface
5.4 The Socket Ahstraction
5.4.1 Sockel 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 Slructure
5.7 Functions In The Sockel API
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 Closesocket Function
5.7.8 The Bind Function
5.7.9 The Listen Function
5.7.10 The Accept Function
5.7.11 Summary Of Socket Calls Used Wilh TCP
5.8 Utility Roulines For Integer Conversion
5.9 Using Socket Culls 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 Inlroduclion
6.2 Leurning, Atgorilhms Instead Of Delails
6.3 Client Architecture
6.4 Idenlifying The Location OfA Server
6.5 Parsing An Address Argumenl
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 Alloating A Socket
6.12 Choosing A Local Protocol Port Number
6.13 A Fundamenlal Problem In Choosing A Local IP Address
6.14 Connecting A TCP Socket To A Server
6.15 Commuiucating 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 Coimected And Unconnected UDP Sockets
6.20 Using Connecl 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 Wai-ning About UDP Unreliability
6.25 Summarv
Chapter 7 Example Client Software
7.1 ntroduction
7.2 T he Imfwrtance Of Small Examples
7.3 Hiding Dpltails
7.4 An Example Pmcedure Library For Client Programs
7.5 Implementiation OfConTCP
7.6 Implementation Of ConUDP
7.7 A Procedure That Forms Connections
7.8 Using The Example Library
7.9 The OA YTIME Service
7.10 Implemenuation OfA TCP Client For DA YTIME
7.11 Reading From A TCP Connection
7.12 The TIME Service
7.13 Accessing The TIME Service
7.14 Accurale 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 UDP Client For The ECHO Service
7.19 Summary
Chapter 8 Algorithms And Issues In Server Software Design
8.1 Inlroduction
8.2 The Conceptual Senver Algorithm
Concurrent Vs. Iferative Servers
Connection-Oriented Vs. Connectionless Access
Connection-Oriented Servers
Connectionless Servers
Failure, Reliability, And Statelessness
Optimizing Stateless Servers
Four Basil' Types Of Servers
Request Processing Time
llerative Server Algorithms
An Iterative, Connection-Oriented Server Algorithm
Binding To A Well-Known Address Using INADDR_ANY
Placing The Socket In Passive Mode
Accepling Connections And Using Them
An Iterative, Connectionless Server Algorithm
Forming A Reply Address In A Connectionless Server
Concurrent Server Algorithms
Masler And Slave Threads
A Concurrent Connectionless Server Algorithm
A Concurrent, Connection-Oriented Server Algorithm
Using Separate Programs As Slaves
Apparenl Concurrency Using A Single Thread
When To Use Each Server Type
A Summary of Server Types
The Important Problem Of Server Deadlock
Alternative Implementations
Summary
Chapter 9 Iterative, Connectionless Servers (UDP)
9.1 Introduction
9.2 Creating A Passive Socket
9.3 Thread Structure
9.4 An Example TIME Server
9.5 Summary
Chapter 10 Iterative, Connection-Oriented Servers (TCP)
10.1 Introduction
10.2 Allocating A Pcassive TCP Socket
10.3 A Server For The DAYTIME Service
10.4 Thread Structure
10.5 An Example DA YTIME Server
10.6 Closing Connections
10.7 Conneclion 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 Thread Slructure
11.5 An Example Concurrent ECHO Server
11.6 Summary
Chapter 12 Singly-Threaded, Concurrent Servers (TCP)
12.1 Introduction
12.2 Data-driven Processing In A Server
12.3 Data-Driven Processing With A Single Thread
12.4 Thread Structure OfA Singly-Threaded Server
12.5 An Example Singly-Threaded ECHO Server
12.6 Summary
Chapter 13 Multiprotocol Servers (TCP, UDP)
13.1 Introduction
13.2 The Motivation For Reducing The Number OfServers
13.3 Multiprotocol Server Design
13.4 Thread Structure
13.5 An Example Multiprotocol DAYTIME Server
13.6 The Concept Of Shared Code
13.7 Concurrent Multiprolocol Servers
13.8 Summary
Chapter 14 Multiservice Servers (TCP, UDP)
14.1 Introduction
14.2 Consolidaling Servers
14.3 A Conneclionless, Multiservice Server Design
14.4 A Connection-Oriented, Multiservice Server Design
14.5 A Concurrent, Connection-Oriented, Multiservice Server
14.6 A Singly-Threaded, 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 An Example Super Server, Inetd
14.12 Summary
Chapter 15 Uniform, Efficient Management Of Server Concurrency
15.1 Introduction
15.2 Choosing Between An Iteralive 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 Thread Preallocation
15.8.1 Preallocation Techniques
15.8.2 Preallocation In A Connection-Oriented Server
15.8.3 Preallocation In A Connectionless Server
15.8.4 Preallocation, Bursty Traffic, And NFS
15.8.5 Preallocation On A Multiprocessor
15.9 Delayed Thread Allocation
15.10 The Uniform Basis For Both Techniques
15.11 Combining Techniques
15.12 Summary
Chapterl6 Concurrency In Clients
16.1 Introduction
16.2 The Advantages Of Concurrency
16.3 The Motivation For Exercising Control
16.4 Concurrenl Contact With Multiple Servers
16.5 Implemenling Concurrent Clients
16.6 Singly-Threaded Implementations
16.7 An Example Concurrent Client That Uses ECHO
16.8 Execution OfThe Concurrent Client
16.9 Managing A Timer
16.10 Example Output
16.11 Concurrency In The Example Code
16.12 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 Allocalion
17.5 Encapsulation And Tunneling
17.6 Tunneling Through An IP Intemet
17.7 Applicalion-Level Tunneling Between Clients And Servers
17.8 Tunneling, Encapsulation, And Dialup Phone Lines
17.9 Summary
Chapter 18 Appiication Level Gateways
18.1 Inlroduction
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 Constraints That Arise 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 Delails OfA Web-Based Application Gateway
18.12 Invoking A CGI Program
18.13 URLs For The RFC Application Gateway
18.14 A General-Purpose Application Gateway
18.15 Operation Of SLIRP
18.16 How SLIRP Handles Connections
18.17 IP Addressing And SURP
18.18 Summary
Chapter 19 External Data Representation (XDR)
19.1 Introduction
19.2 Representations For Data In Computers
19.3 The N-Squared Conversion Problem
Network Standard Byte Order
A De Facto Standard External Data Representation
XDR Datu Types
Implicil Types
Software Supporl For Using XDR
XDR Library Routines
Building A Message One Piece At A Time
Conversion Routines In The XDR Library
XDR Streams. 1/0, and TCP
Records, Record Boundaries, And Datagram 1/0
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 Modet 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 Definition
20.11 Remote Programs And Procedures
20.12 Reducing The Number Of Arguments
20.13 Identifying Remote Programs And Procedures
20.14 Accommodating Multiple Versions OfA 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 Relransmission
20.19 Mapping A Remote Program To A Protocol Port
20.20 Dynamic Porl Mapping
20.21 RPC Port Mapper 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 OfAn Authentication Field
20.27 Summary
Chapter 21 Distributed Program Generation (Rpcgen Concept)
21.1 Introduction
21.2 Using Remote Procedure Calls
21.3 Programming Mechanisms To Support RPC
21.4 Dividing A Program Inlo Local And Remote Procedures
21.5 Adding Code For RPC
21.6 Stub Procedures
21.7 Mulliple Remote Procedures And Dispatching
21.8 Name Of The Client-Side Slub Procedure
21.9 Using Rpcgen To Generate Distributed Programs
21.10 Rpcgen Output And Interface Procedures
21.11 Rpcgen Input And Output
21.12 Using Rpcgen To Build A Client And Server
21.13 Summary
Chapter 22 Distributed Program Generation (Rpcgen Example)
22.1 Introduction
22.2 An Example To lllustrate Rpcgen
22.3 Diclionary Look Up
22.4 Eight Steps To A Distributed Application
22.5 Slep 1: Build A Conventional Application Program
22.6 Step 2: Divide The Program Into Two Parts
22.7 Step 3: Create An Rpcgen 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 Inlerface Routines
22.13.2 Server-Side Interface Routines
22.14 Step 6: Compile And Link The Client Program
22.15 Slep 7: Compile And Link The Server Program
22.16 Step 8: Start The Server And Execute The Client
22.17 Summarv
Chapter 23 Network File System Concepts (NFS)
23.1 Introduction
23.1 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 Semanlics
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
23.7.72 UNIX File Names And Paths
23.7.13 The UNIX tnode: 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 NFS Handles Replace Path Names
23.18 An NFS Client Under Windows
23.19 File Positioning With A Stateless Server
23.20 Operations On Directories
23.21 Reading A Directory Slatelessly
23.22 Mulliple Hierarchies In An NFS Server
23.23 The Mount Protocol
23.24 Summary
Chapter 24 Network File System Protocol (NFS, Mount)
24.1 Inlroduction
24.2 Using RPC To Define A Protocol
24.3 Defining A Protocol With Data Structures And Procedures
24.4 NFS Conslanl, Type, And Data Declarations
24.4.1 NFSConstants
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 (Procedure 0)
24.6.2 NFSPROC_GETA TTR (Procedure 1)
24.6.3 NFSPROC_SETATTR (Procedure 2)
24.6.4 NFSPROC_ROOT (Procedure 3) [Ohsolete in NFS3]
24.6.5 NFSPROC_OOKUP (Procedure 4)
24.6.6 NFSPROC_READLlNK (Procedure 5)
24.6.7 NFSPROC_READ (Procedure 6)
24.6.8 NFSPROC_WRITECACHE (Procedure 7) [Obsolele in NFS3]
24.6.9 NFSPROC_WRITE (Procedure 8)
24.6.10 NFSPROC_REATE (Procedure 9)
24.6.11 NFSPROC_REMOVE (Procedure 10)
24.6.12 NFSPROC_RENAME (Procedure 11)
24.6.13 NFSPROC_LINK (Procedure 12)
24.6.14 NFSPROC_SYMUNK (Procedure 13)
24.6.15 NFSPROC_MKDIR (Procedure 14)
24.6.16 NFSPROC_RMD1R (Procedure 15)
24.6.17 NFSPROC_READDlR (Procedure 16)
24.6.18 NFSPROC_STATFS (Procedure 17)
24.7 The Mount Protocol
24.7.1 Mount Constant Definitions
24.7.2 Mount Ty'pe Definitions
24.7.3 Mount Data Structures
24.8 Procedures In The Mount Protocol
24.9 Semantics of Mount Operations
24.9.1 MNTPROC_ULL (Procedure 0)
24.9.2 MNTPROC_MNT (Procedure 1)
24.9.3 MNTPROC_DUMP (Procedure 2)
24.9.4 MNTPROC_MNT (Procedure 3)
24.9.5 MNTPROC_UMNTALL (Procedure 4)
24.9.6 MNTPROC_EXPORT (Procedure 5)
24.10 NFS And Moimt Authentication
24.11 Changes In NFS Version 3
24.12 Summarv
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 Tenninals, Windows, and Files
25.2.4 The Need For Concurrency
25.2.5 A Thread Model For A TELNET Client
25.3 A TELNET Client Algorithm
25.4 Keyboard 1/0 In Windows
25.5 Global Variables Used For Keyboard Control
25.6 Initializing The Keyboard Thread
25.7 Finite Stale Machine Specification
25.8 Embedding Commands In A TELNET Data Stream
25.9 Option Negotiation
25.10 Request/Offer Symmetry
25.11 TELNET Character Definitions
25.12 A Finite State Machine For Data From The Server
25.13 Transitions Among States
25.14 A Finite State Machine Implementation
25.15 A Compact FSM Representa'tion
25.16 Keeping The Compact Representation At Run-Time
25.17 Implementation OfA Compact Representation
25.18 Building An FSM Transition Matrix
25.19 The Socket Output Finite State Machine
25.20 Definitions For The Socket Output FSM
25.21 The Option Subnegotiation Finite State Machine
25.22 Definitions For The Option Subnegotiation FSM
25.23 FSM Initialization
25.24 Arguments For The TELNET Client
25.25 The Heart Of The TELNET Client
25.26 TELNET Synchronization
25.27 Handling A Severe Error
25.28 Implemenlation Of The Main FSM
25.29 A Procedure For Immediate Disconnection
25.30 Abort Procedure
25.31 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 Requesl
26.4 Performing No Operation
26.5 Responding To WILLWONT For The Echo Oplion
26.6 Sending A Response
26.7 Responding To WILUWONT For Unsupported Options
26.8 Responding To WLLWONT For The No Go-Ahead Option
26.9 Generating DO/DONT For Binary Transmission
26.10 Responding To DO/DONT For Unsupporled Options
26.11 Responding To DO/DONT For Transmit Binary Option
26.12 Responding To DO/DONT For The Terminal Type Option
26.13 Option Subnegoliation
26.14 Sendmg Terminal Type Information
26.15 Tennincning Suhnegotiation
26.16 Sending A Character To The Server
26.17 Displaying Incoming Data On The User's Terminal
26.18 Writing A Block Of Data To The Server
26.19 Interacting With The Local Client
26.20 Responding To lllegat Commands
26.21 Scripting To A File
26.22 Implementation Of Scripting
26.23 Initialzation Of Scripting
26.24 Collecting Characters OfThe Script File Name
26.25 Opening A Script File
26.26 Terminating Scripting
26.27 Printing Status Information
26.28 Summarv
Chapter 27 Porting Servers From UNIX To Windows
27.1 Introduction
27.2 Operating in Background
27.3 Shared Descriptors And Inherilance
27.4 The Controlling TTY
27.5 Working Directories
27.6 File Creattion And Umask
27.7 Process Groups
27.8 Descriptors For Slandard 1/0
27.9 Mutual Exclusion For A Server
27.70 Recording A Process ID
27.11 Waiting For A Child Process To Exit
27.12 Using A Syslem Log Facility
27.12.1 Generating Log Messages
27.13 Miscellaneous Incompatibilities
27.14 Summarv
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 Starvalion Among A Set Of Clients And A Server
28.8 Busy Connections And Starvation
28.9 Avoiding Blocking Operations
28.10 Threads, Connections, And Other Limits
28.11 Cycles Of Clients And Servers
28.12 Documenting Dependencies
28.13 Summary
Appendix 1 Functions And Library Routines Used With Sockets
Appendix 2 Manipulation Of Windows Socket Descriptors
Bibliography
Index
