Hands-On Network Programming with C

▶Book Description
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 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 be ready to overcome challenges in network programming with the powerful C language.

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.

▶What You Will Learn
- Uncover cross-platform socket programming APIs
- Implement techniques for supporting IPv4 and IPv6
- Understand how TCP and UDP connections work over IP
- Discover how hostname resolution and DNS work
- Interface with web APIs using HTTP and HTTPS
- Explore Simple Mail Transfer Protocol (SMTP) for electronic mail transmission
- Apply network programming to the Internet of Things (IoT)

▶Key Features
- Apply your C/C programming skills to build powerful network applications
- Get to grips with a variety of network protocols that allow you to load web pages, send emails, and do much more
- Write portable network code for Windows, Linux, and macOS

▶Who This Book Is For
If you're a developer or a system administrator who wants to get started with network programming, this book is for you. Basic knowledge of C programming is assumed.

▶What this book covers
- Chapter 1, Introducing Networks and Protocols, introduces the important concepts related to networking. This chapter includes example programs to determine your IP address pragmatically.

- Chapter 2, Getting to Grips with Socket APIs, introduces socket programming APIs and has you build your first networked program—a tiny web server.

- Chapter 3, An In-Depth Overview of TCP Connections, focuses on programming TCP sockets. In this chapter, example programs are developed for both the client and server sides.

- Chapter 4, Establishing UDP Connections, covers programming with User Datagram Protocol (UDP) sockets.

- Chapter 5, Hostname Resolution and DNS, explains how hostnames are translated into IP addresses. In this chapter, we build an example program to perform manual DNS query lookups using UDP.

- Chapter 6, Building a Simple Web Client, introduces HTTP—the protocol that powers websites. We dive right in and build an HTTP client in C.

- Chapter 7, Building a Simple Web Server, describes how to construct a fully functional web server in C. This program is able to serve a static website to any modern web browser.

- Chapter 8, Making Your Program Send Email, describes Simple Mail Transfer Protocol (SMTP)—the protocol that is powering email. In this chapter, we develop a program that can send email over the internet.

- Chapter 9, Loading Secure Web Pages with HTTPS and OpenSSL, explores TLS—the protocol that secures web pages. In this chapter, we develop an HTTPS client that is capable of downloading web pages securely.

- Chapter 10, Implementing a Secure Web Server, continues on the security theme and explores the construction of a secure HTTPS web server.

- Chapter 11, Establishing SSH Connections with libssh, continues with the secure protocol theme. The use of Secure Shell (SSH) is covered to connect to a remote server, execute commands, and download files securely.

- Chapter 12, Network Monitoring and Security, discusses the tools and techniques used to test network functionality, troubleshoot problems, and eavesdrop on insecure communication protocols.

- Chapter 13, Socket Programming Tips and Pitfalls, goes into detail about TCP and addresses many important edge cases that appear in socket programming. The techniques covered are invaluable for creating robust network programs.

- Chapter 14, Web Programming for the Internet of Things, gives an overview of the design and programming for Internet of Things (IoT) applications.

- Appendix A, Answers to Questions, provides answers to the comprehension questions given at the end of each chapter.

- Appendix B, Setting Up Your C Compiler on Windows, gives instructions for setting up a development environment on Windows that is needed for compiling all of the example programs in this book.

- Appendix C, Setting Up Your C Compiler on Linux, provides the setup instructions for preparing your Linux computer to be capable of compiling all of the example programs in this book.

- Appendix D, Setting Up Your C Compiler on macOS, gives step-by-step instructions for configuring your macOS system to be capable of compiling all of the example programs in this book.

- Appendix E, Example Programs, lists each example program, by chapter, included in this book's code repository.