Wireless Hacks, 2nd Edition

Chapter 5. Software Hacks

Hacks 63–82: Introduction

One of the joys of wireless hacking is that it encompasses both the hardware and software worlds. If you’re not comfortable with soldering irons, but you can hack Perl or C, many great things are waiting for you to hack. Software hacks permeate the wireless world, from alternate drivers to replacement firmware.

This chapter covers a wide range of subjects, from advertising services over your wireless, to using captive portals, to building your own access point using Linux or BSD.

Build Your Own Access Point with Linux

Run your own access point with off-the-shelf radio cards and open source drivers.

Commercial access points have multiple functions. Not only do they have 802.11a/b/g radios, but they also function as the master of any client radio that connects to the AP in Infrastructure mode. Access points broadcast beacon frames, which advertise the ESSID of the access point. Once a client associates, the access point manages all radio communications, following sets of algorithms to control radio traffic between multiple clients.

The challenge here is to accomplish the same task without the custom chipsets and firmware in commercial access points. You want to build your own access point using a laptop (or other PC hardware), a radio card, and some software.

Hardware Choices

What you choose to build your access point really depends on how and where you want to use it:

Mobile

If you have a notebook, isn’t that a perfect platform to always ...