internerworking with tcp/ip vol 3 windows sockets

Contents

1 Introduction And Overview.......................................................................................1

1.1 Use Of TCP/IP..........................................................................................1

1.2 Designing Applications For A Distributed Environment...........................2

1.3 Standard And Nonstandard Application Protocols....................................2

1.4 An Example Of Standard Application Protocol Use.................................2

1.5 An Example Connection...........................................................................3

1.6 Using TELNET To Access An Alternative Service...................................4

2 The Client Server Model And Software Design........................................................9

2.1 Introduction...............................................................................................9

2.2 Motivation.................................................................................................9

2.3 Terminology And Concepts.....................................................................10

2.3.1 Clients And Servers.........................................................................10

2.3.2 Privilege And Complexity...............................................................11

2.3.3 Standard Vs. Nonstandard Client Software.....................................11

2.3.4 Parameterization Of Clients............................................................12

2.3.5 Connectionless Vs. Connection-Oriented Servers...........................13

2.3.6 Stateless Vs. Stateful Servers..........................................................14

3 Concurrent Processing In Client-Server Software..................................................20

3.1 Introduction.............................................................................................20

3.2 Concurrency In Networks.......................................................................20

3.3 Concurrency In Servers...........................................................................22

3.4 Terminology And Concepts.....................................................................23

3.4.1 The Process Concept.......................................................................23

3.4.2 Threads............................................................................................24

3.4.3 Programs vs. Threads......................................................................25

3.4.4 Procedure Calls...............................................................................25

3.5 An Example Of Concurrent Thread Creation..........................................26

3.9 Concurrency Under UNIX......................................................................32

3.10 Executing A Separately Compiled Program............................................34

3.11 Summary.................................................................................................34

3.12 FOR FURTHER STUDY........................................................................35

3.13 EXERCISES...........................................................................................35

4 Program Interface To Protocols...............................................................................36

4.1 Introduction.............................................................................................36

4.2 Loosely Specified Protocol Software Interface.......................................36

4.2.1 Advantages And Disadvantages......................................................37

4.3 Interface Functionality............................................................................37

4.10 FOR FURTHER STUDY........................................................................43

4.11 EXERCISES...........................................................................................43

5 The Socket API.......................................................................................................45

5.1 Introduction.............................................................................................45

5.2 The History Of Sockets...........................................................................45

5.3 Specifying A Protocol Interface..............................................................46

5.4 The Socket Abstraction...........................................................................47

5.4.1 Socket Descriptors...........................................................................47

5.4.2 System Data Structures For Sockets................................................48

5.4.3 Using Sockets..................................................................................48

5.6 A Generic Address Structure...................................................................49

5.7 Functions In The Socket API...................................................................51

5.7.1 The WSAStartup Function..............................................................51

5.7.2 The WSACIeanup Function............................................................52

5.7.9 The Listen Function........................................................................53

5.7.10 The Accept Function.......................................................................54

5.7.11 Summary Of Socket Calls Used With TCP.....................................54

5.8 Utility Routines For Integer Conversion.................................................54

5.9 Using Socket Calls In A Program............................................................55

5.10 Symbolic Constants For Socket Call Parameters....................................56

5.11 Summary.................................................................................................57

5.12 FOR FURTHER STUDY........................................................................58

5.13 EXERCISES...........................................................................................58

6 Algorithms And Issues In Client Software Design.................................................59

6.7 Looking Up A Well-Known Port By Name.............................................64

6.8 Port Numbers And Network Byte Order.................................................64

6.9 Looking Up A Protocol By Name...........................................................64

6.10 The TCP Client Algorithm......................................................................65

6.11 Allocating A Socket.................................................................................66

6.12 Choosing A Local Protocol Port Number................................................66

6.13 A Fundamental Problem In Choosing A Local IP Address......................66

6.14 Connecting A TCP Socket To A Server...................................................67

6.15 Communicating With The Server Using TCP.........................................68

6.16 Reading A Response From A TCP Connection.......................................69

6.17.1 The Need For Partial Close.............................................................69

6.17.2 A Partial Close Operation................................................................70

6.18 Programming A UDP Client....................................................................70

6.19 Connected And Unconnected UDP Sockets............................................71

6.26 FOR FURTHER STUDY........................................................................73

6.27 EXERCISES...........................................................................................73

7 Example Client Software........................................................................................75

7.1 Introduction.............................................................................................75

7.2 The Importance Of Small Examples.......................................................75

7.3 Hiding Details.........................................................................................76

7.4 An Example Procedure Library For Client Programs.............................76

7.5 Implementation Of ConTCP...................................................................77

7.6 Implementation Of ConUDP...................................................................77

7.7 A Procedure That Forms Connections.....................................................78

7.14 Accurate Times And Network Delays.....................................................85

7.15 A UDP Client For The TIME Service.....................................................85

7.16 The ECHO Service..................................................................................88

7.17 A TCP Client For The ECHO Service.....................................................88

7.18 A UDP Client For The ECHO Service....................................................90

7.19 Summary.................................................................................................92

7.20 FOR FURTHER STUDY........................................................................92

7.21 EXERCISES...........................................................................................93

8 Algorithms And Issues In Server Software Design.................................................95

8.1 Introduction.............................................................................................95

8.3 Concurrent Vs. Iterative Servers.............................................................96

8.4 Connection-Oriented Vs. Connectionless Access...................................96

8.5 Connection-Oriented Servers..................................................................97

8.6 Connectionless Servers...........................................................................98

8.13 Binding To A Well-Known Address Using INADDR_ANY.................103

8.14 Placing The Socket In Passive Mode....................................................104

8.15 Accepting Connections And Using Them.............................................104

8.16 An Iterative, Connectionless Server Algorithm.....................................104

8.17 Forming A Reply Address In A Connectionless Server.........................104

8.18 Concurrent Server Algorithms..............................................................105

8.19 Master And Slave Threads....................................................................106

8.20 A Concurrent, Connectionless Server Algorithm..................................106

8.21 A Concurrent, Connection-Oriented Server Algorithm.........................107

8.22 Using Separate Programs As Slaves......................................................108

8.29 FOR FURTHER STUDY......................................................................112

8.30 EXERCISES.........................................................................................112

9 Iterative, Connectionless Servers (UDP)..............................................................114

9.1 Introduction...........................................................................................114

9.2 Creating A Passive Socket.....................................................................114

9.3 Thread Structure....................................................................................117

9.4 An Example TIME Server.....................................................................118

9.5 Summary...............................................................................................120

9.6 FOR FURTHER STUDY......................................................................120

9.7 EXERCISES.........................................................................................121