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

Socket's local address

When implementing servers, for both TCP and UDP, it is important to bind the listening socket to a local address and port. If the socket isn't bound, then clients can't know where to connect.

It is also possible to use bind() on the client side to associate a socket with a particular address and port. It is sometimes useful to use bind() in this manner on machines that have multiple network interfaces. The use of bind() can allow the selection of which network address to use for the outgoing connection.

Sometimes, bind() is used to set the local port for an outgoing connection. This is usually a bad idea for a few reasons. First, it very seldom serves any purpose. The port number presented to the connected server is likely to be different because of network address translation regardless. Binding to a local port also invites the error of selecting a port that is already in use. Usually, the operating system takes care of selecting a free port. This use of bind() also...