Tài liệu Network_programming_in_NET_with_CSharp_and_VBNET_D igital_Press

1 Understanding the Internet and Network Programming 1

1.1 Introduction 1
1.2 Why network programming in .NET? 2
1.3 What can a network program do? 2
1.4 IP addresses 3
1.5 The network stack 6
1.6 Ports 7
1.7 Internet standards 7
1.8 What is .NET? 9
1.9 Getting started 11
1.10 Using Visual Studio .NET 12
1.11 Using the .NET SDK 16
1.11.1 Compiling with Visual Basic.NET 19
1.11.2 Compiling with C# 20
1.11.3 Testing the application 20
1.12 Conclusion 20
2 I/O in the .NET Framework 21

2.1 Introduction 21
2.2 Streams 21
2.2.1 Streams for files 22
2.2.2 Encoding data 28
2.2.3 Binary and text streams 29
2.2.4 Serialization 33
2.2.5 Writing a database to a stream 44
2.3 Conclusion 54

3 Working with Sockets 55

3.1 Introduction 55
3.2 What is a socket? 55
3.3 Creating a simple “hello world” application 56
3.3.1 Writing a simple UDP client 57
3.3.2 Writing a simple UDP server 58
3.4 Using TCP/IP to transfer files 62
3.4.1 Writing a simple TCP/IP client 62
3.4.2 Writing a simple TCP/IP server 65
3.5 Debugging network code 73
3.6 Socket-level networking in .NET 75
3.7 Conclusion 86

4 HTTP: Communicating with Web Servers 87

4.1 Introduction 87
4.1.1 Data mining 88
4.2 HTTP 88
4.2.1 The HTTP request 88
4.2.2 The HTTP response 91
4.2.3 MIME types 93
4.2.4 System.Web 93
4.2.5 Posting data 97
4.2.6 A note on cookies 104
4.2.7 A WYSIWYG editor 105
4.3 Web servers 113
4.3.1 Implementing a Web server 114
4.4 System.Net.HttpWebListener 124
4.5 Mobile Web browsers 128
4.5.1 Mobile Web SDK 130
4.6 Conclusion 130
5 SMTP and POP3: Communicating with email Servers 131

5.1 Introduction 131
5.2 Sending an email 131
5.3 SMTP 132
5.3.1 Implementing SMTP 133
5.4 Post office protocol 3 140
5.4.1 Implementing POP3 141
5.5 System.Web.Mail 148
5.5.1 Attachments 151
5.5.2 Images 153
5.6 Mail application programming interface 153
5.6.1 Accessing the address book 156
5.6.2 IMAP 158
5.6.3 Network news transfer protocol 159
5.7 Conclusion 161

6 FTP: Communicating with File Servers 163

6.1 Background 163
6.2 Microsoft file sharing 163
6.3 Netware file sharing 164
6.4 An overview of FTP 165
6.4.1 How FTP uses ports 167
6.4.2 The FTP handshake 168
6.4.3 Navigating folders 170
6.4.4 FTP command reference 171
6.4.5 Implementing FTP 172
6.4.6 Implementing FTP with the Internet Transfer Control 174
6.4.7 A more substantial implementation of FTP 178
6.4.8 FTP support in .NET 2.0 193
6.5 Conclusion 194

7 Securing a Network: Firewalls, Proxy Servers,
and Routers 195

7.1 Introduction 195
7.1.1 Building a network from scratch 195
7.2 Building an enterprise network 199
7.2.1 Routers 199
7.2.2 Firewalls 200
7.3 Tunneling out of an enterprise network 203
7.4 Avoiding the networking pitfalls 205
7.4.1 Firewall tunneling 206
7.5 Conclusion 207

8 Protecting Data: Encryption 209

8.1 Introduction 209
8.2 Cryptanalysis 209
8.3 Terminology 212
8.4 Asymmetric encryption 212
8.5 Using RSA as asymmetric encryption 213
8.6 Symmetric encryption 218
8.6.1 Using 3DES as symmetric encryption 218
8.7 Piracy protection 224
8.8 Conclusion 225

9 Controlling User Access: Authentication
and Authorization 227

9.1 Introduction 227
9.2 Authentication techniques 227
9.2.1 IIS authentication 228
9.3 Microsoft .NET Passport authentication 230
9.4 Hashing information 232
9.4.1 Hashing algorithms 234
9.4.2 Using SHA 234
9.5 SSL 236
9.6 Certificates 236
9.7 Server certificates 238
9.8 Client certificates 239
9.8.1 Microsoft Certificate Services 240
9.8.2 Reading certificates 241
9.9 Permissions in .NET 244
9.10 Financial network security 246
9.10.1 X.25 247
9.10.2 ISO 8730 247
9.10.3 SWIFT 248
9.10.4 Corporate transactions 248
9.11 Conclusion 249
10 Programming for Scalability 251

10.1 Introduction 251
10.2 Case study: The Google search engine 251
10.3 Replication and redundancy 253
10.4 Scalable network applications 254
10.5 Future proofing 255
10.6 Thread pooling 256
10.6.1 Implementing a thread pool 258
10.7 Avoiding deadlocks 261
10.8 Load balancing 262
10.9 Conclusion 272

11 Optimizing Bandwidth Utilization 275

11.1 Introduction 275
11.2 Tricks and tips to increase performance 275
11.2.1 Caching 276
11.2.2 Keep-alive connections 277
11.2.3 Progressive downloads 278
11.2.4 Tweaking settings 278
11.3 Multicast UDP 282
11.3.1 Multicast basics 282
11.3.2 Multicast routing 283
11.3.3 Implementing multicast 284
11.4 Data compression 289
11.5 Lossless compression 290
11.5.1 Implementing ZIP compression 291
11.6 Lossy compression 296
11.6.1 Audio compression 296
11.6.2 Image compression 298
11.6.3 Video compression 302
11.7 Conclusion 303

12 Ping, DNS, and WHOIS: Monitoring your Network 305

12.1 Introduction 305
12.2 DNS 305
12.2.1 Implementing DNS MX 306
12.3 Ping 314
12.4 WHOIS 321
12.4.1 Telnet 326
12.5 Other members of the TCP/IP suite 327
12.5.1 ARP 327
12.5.2 RIP 327
12.5.3 OSPF 328
12.5.4 BGP/EGP 328
12.5.5 SNMP 328
12.5.6 PPP 328
12.6 WMI 329
12.6.1 Reading WMI data 330
12.6.2 Leveraging WMI 333
12.7 Conclusion 336

13 Analyzing Network Packets 337

13.1 Introduction 337
13.2 IP-level network tapping 339
13.2.1 Interpreting raw network data 344
13.2.2 IP packets in detail 346
13.2.3 ICMP packets in detail 348
13.2.4 TCP/IP packets in detail 349
13.2.5 UDP packets in detail 351
13.2.6 DNS packets in detail 352
13.3 Layer 2 network tapping 354
13.3.1 Using rvPacket and WinPCap 354
13.3.2 Using PacketX and WinPCap 360
13.4 Physical network tapping 366
13.5 Conclusion 376

14 Adding Digital Telephony 379

14.1 Introduction 379
14.2 Basic telephony 380
14.3 Listening for incoming phone calls 382
14.4 DTMF tones 399
14.5 Audio playback 401
14.5.1 Audio playback over TAPI 413
14.6 Conclusion 417

15 Message Queues 419

15.1 Introduction 419
15.2 MSMQ 420
15.3 Implementing a message queue 420
15.3.1 Queuing complex objects 427
15.3.2 Transactions 435
15.3.3 Acknowledgments 437
15.4 Timeouts 439
15.5 Journal 441
15.6 Queued Components 443
15.7 Security 447
15.8 Scalability 449
15.9 Performance issues 451
15.10 Conclusion 452

16 IPv6: Programming for the Next-generation Internet 453

16.1 Introduction 453
16.2 What is IPv6? 453
16.3 The history of IPv6 454
16.4 So what changes? 455
16.5 IPv6 naming conventions 456
16.6 Installing IPv6 457
16.6.1 Auto configuration 457
16.7 Using IPv6 utilities 458
16.7.1 IPv6 458
16.7.2 NETSH 459
16.7.3 Ping6 459
16.7.4 Tracert6 460
16.7.5 IPSec6 461
16.7.6 Windows 2000 specific 463
16.8 IPv6 routing 464
16.8.1 Route determination process 465
16.8.2 Administering the IPv6 routing table 466
16.8.3 IPv6 routing advertisements 468
16.9 IPv6 coexistence 469
16.9.1 The 6to4 protocol 469
16.9.2 The ISATAP protocol 471
16.9.3 The 6over4 protocol 473
16.10 IPv6 in .NET 473
16.11 Conclusion 479

17 Web Services and Remoting 481

17.1 Introduction 481
17.2 Creating a Web service 481