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

Name/address translation functions

It is common for networked programs to need to translate text-based representatives of an address or hostname into an address structure required by the socket programming API. The common function we've been using is getaddrinfo(). It is a useful function because it is highly portable (available on Windows, Linux, and macOS), and it works for both IPv4 and IPv6 addresses.

It is also common to need to convert a binary address back into a text format. We use getnameinfo() for this.

Using getaddrinfo()

Although we've been using getaddrinfo() in previous chapters, we'll discuss it in more detail here.

The declaration for getaddrinfo() is shown in the following code:

int getaddrinfo(const char *node,
                const char *service,
                const struct addrinfo *hints,
                struct addrinfo **res);

The preceding code snippet is explained as follows:

  • node specifies a hostname or address as a string. Valid examples could be, 192.168...