Beej's Guide to Network Programming

Using Internet Sockets

Brian "Beej Jorgensen" Hall
beej@beej.us

Version 3.0.14
September 8, 2009

Copyright © 2009 Brian "Beej Jorgensen" Hall


Contents


1. Intro
1.1. Audience
1.2. Platform and Compiler
1.3. Official Homepage and Books For Sale
1.4. Note for Solaris/SunOS Programmers
1.5. Note for Windows Programmers
1.6. Email Policy
1.7. Mirroring
1.8. Note for Translators
1.9. Copyright and Distribution

2. What is a socket?
2.1. Two Types of Internet Sockets
2.2. Low level Nonsense and Network Theory

3. IP Addresses, structs, and Data Munging
3.1. IP Addresses, versions 4 and 6
3.2. Byte Order
3.3. structs
3.4. IP Addresses, Part Deux

4. Jumping from IPv4 to IPv6

5. System Calls or Bust
5.1. getaddrinfo()—Prepare to launch!
5.2. socket()—Get the File Descriptor!
5.3. bind()—What port am I on?
5.4. connect()—Hey, you!
5.5. listen()—Will somebody please call me?
5.6. accept()—"Thank you for calling port 3490."
5.7. send() and recv()—Talk to me, baby!
5.8. sendto() and recvfrom()—Talk to me, DGRAM-style
5.9. close() and shutdown()—Get outta my face!
5.10. getpeername()—Who are you?
5.11. gethostname()—Who am I?

6. Client-Server Background
6.1. A Simple Stream Server
6.2. A Simple Stream Client
6.3. Datagram Sockets

7. Slightly Advanced Techniques
7.1. Blocking
7.2. select()—Synchronous I/O Multiplexing
7.3. Handling Partial send()s
7.4. Serialization—How to Pack Data
7.5. Son of Data Encapsulation
7.6. Broadcast Packets—Hello, World!

8. Common Questions

9. Man Pages
9.1. accept()
9.2. bind()
9.3. connect()
9.4. close()
9.5. getaddrinfo(), freeaddrinfo(), gai_strerror()
9.6. gethostname()
9.7. gethostbyname(), gethostbyaddr()
9.8. getnameinfo()
9.9. getpeername()
9.10. errno
9.11. fcntl()
9.12. htons(), htonl(), ntohs(), ntohl()
9.13. inet_ntoa(), inet_aton(), inet_addr
9.14. inet_ntop(), inet_pton()
9.15. listen()
9.16. perror(), strerror()
9.17. poll()
9.18. recv(), recvfrom()
9.19. select()
9.20. setsockopt(), getsockopt()
9.21. send(), sendto()
9.22. shutdown()
9.23. socket()
9.24. struct sockaddr and pals

10. More References
10.1. Books
10.2. Web References
10.3. RFCs

Index