Obtain Monitoring Mode for Intels WiFi Driver iwlagn (Patching)
, 29 Mar, 2011
Actually, there are only three things to say about WEP: It is insecure, it is insecure and it is insecure. I suppose, everybody half-way technophilic has heard about breaking into such networks within minutes or even seconds. In order to achieve this goal and assure oneself of the simpleness, every Ubuntu user can use the generic software toolkit out of the official package sources with ones own wireless network. How this can be done is documented on several sites and is not topic of this blog post. Being owner of Intels WiFi 5100, one has to take some hurdles first, namely patching the corresponding driver iwlagn. Concerning this matter, one can find a tutorial following.
Unversed user will realize soon that this text is not addressed to them. If you can not associate some terms to anything, you probably should reconsider your “funny hack”. And, stating explicitly, these patches serve only the monitoring mode. If you do not want to use your Wireless LAN that way, you need not (and should not) experiment with it.
There is no problem with the standard monitoring mode. You can activate it as normal.
The (minus) First Problem
The Problem arises when you want to connect to an access point. Because then an error appears concerning the return value of the current channel of the monitor-interface (in my case
mon0). It turns out to always be
-1, delivering such a warning:
mon0 is on channel -1, but the AP uses channel 6
In order to solve it, there is a simple named patch with “channel negative minus one” in it. The Patching process itself takes place as usual, also with current kernels like 2.6.38.
The Second Problem
Somewhat more difficult is the second problem, because the patch applies to various parts of the driver in order to allow injection. I use an patch attending to the FRAG, ACK and RADIOTAP which came into life for 2.6.32-2. Most hunks apply quietly, but there is one (or two?) which I had to satisfy by hand. For that, simply put in the rejected parts at the designated place yourself. All you need is a text editor with searching functionality.
Patching the Kernel or Driver?
Although I spoke of the driver all the time, I myself patch the whole kernel each time I build it because I ran into obstacles with the compat-wireless driver package.
By the way, I do not have any setbacks since working with this patched driver in my common wireless environments. To summarize, one get an iwlagn which works great in every situation without the need of switching the driver modules.
By the bye: WEP is insecure.