Book Image

Hands-On Network Programming with C

By : Lewis Van Winkle
Book Image

Hands-On Network Programming with C

By: Lewis Van Winkle

Overview of this book

Network programming enables processes to communicate with each other over a computer network, but it is a complex task that requires programming with multiple libraries and protocols. With its support for third-party libraries and structured documentation, C is an ideal language to write network programs. Complete with step-by-step explanations of essential concepts and practical examples, this C network programming book begins with the fundamentals of Internet Protocol, TCP, and UDP. You’ll explore client-server and peer-to-peer models for information sharing and connectivity with remote computers. The book will also cover HTTP and HTTPS for communicating between your browser and website, and delve into hostname resolution with DNS, which is crucial to the functioning of the modern web. As you advance, you’ll gain insights into asynchronous socket programming and streams, and explore debugging and error handling. Finally, you’ll study network monitoring and implement security best practices. By the end of this book, you’ll have experience of working with client-server applications and be able to implement new network programs in C. The code in this book is compatible with the older C99 version as well as the latest C18 and C++17 standards. You’ll work with robust, reliable, and secure code that is portable across operating systems, including Winsock sockets for Windows and POSIX sockets for Linux and macOS.
Table of Contents (26 chapters)
Title Page
About Packt

Chapter 3. An In-Depth Overview of TCP Connections

In Chapter 2, Getting to Grips with Socket APIs, we implemented a simple TCP server that served a web page with HTTP. In this chapter, we will begin by implementing a TCP client. This client is able to establish an IPv4 or IPv6 TCP connection with any listening TCP server. It will be a useful debugging tool that we can reuse in the rest of this book.

Our TCP server from the last chapter was limited to accepting only one connection. In this chapter, we will look at multiplexing techniques to allow our programs to handle many separate connections simultaneously.

The following topics are covered in this chapter:

  • Configuring a remote address with getaddrinfo()
  • Initiating a TCP connection with connect()
  • Detecting terminal input in a non-blocking manner
  • Multiplexing with fork()
  • Multiplexing with select()
  • Detecting peer disconnects
  • Implementing a very basic microservice
  • The stream-like nature of TCP
  • The blocking behavior of send()