TCP/IP Illustrated

Chapter 17. Socket Options

17.1. Introduction

We complete our discussion of the socket layer in this chapter by discussing several system calls that modify the behavior of sockets.

The setsockopt and getsockopt system calls were introduced in Section 8.8, where we described the options that provide access to IP features. In this chapter we show the implementation of these two system calls and the socket-level options that are controlled through them.

The ioctl function was introduced in Section 4.4, where we described the protocol-independent ioctl commands for network interface configuration. In Section 6.7 we described the IP specific ioctl commands used to assign network masks as well as unicast, broadcast, and destination ...