Beej's Guide to Network Programming

Using Internet Sockets

Brian "Beej Jorgensen" Hall
[e-mail]

Version 3.0.15
July 3, 2012

Copyright © 2012 Brian "Beej Jorgensen" Hall

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Contents

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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 callme?

5.6. accept()—"Thank you for calling port3490."

5.7. send() and recv()—Talk to me,baby!

5.8. sendto() andrecvfrom()—Talk to me, DGRAM-style

5.9. close() andshutdown()—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