Introduction

Linux has support for a lot of advanced networking features, these include firewalls, QoS support in the form of queues, classes and filters, traffic conditioning, netlink sockets etc.This document discusses briefly about netlink sockets from the implementation and usage point of view. Section 2 gives an overview of the creation and usage of netlink sockets and how in general protocol families are registered in the kernel, Section 3 explains packaging a netlink packet from user space with an example and how this packet is handled in the kernel. Also a complete example code listing is provided in the appendix.