Subject: Re: access point list from Lucent wireless cards
To: Bill Studenmund <>
From: Michael Graff <>
List: current-users
Date: 09/22/2001 09:53:03
Bill Studenmund <> writes:

> The concensus I'd heard when I asked the right way to do this was that
> we'd need to teach bpf about 802.11 frames, i.e. DLT_IEEE80211. I'm not
> sure how a bpf user would say it wanted to get one or the other.

One thing to note is that the driver may have some custom bits to
inject before the 802.11 header, such as received signal strength,
data rate, etc.  I'd like to retain that if possible.

I now have two modes the _driver_ can be put in -- one is standard
mode where 802.11 frames are not returned, but translated into 802.3.

The other mode is a raw mode where the wi_frame portion is returned,
followed by raw packet data.  This is a special "monitor" mode, and
is only returned after an ioctl tells the prism2 chip to return all
seen data in promiscious mode.  The obvious reason for that is to
experiment with airsnort (which I have cracking my home network's
keys now)

Changing the BPF type will break dhcp, I believe, unless the default
mode is normal ethernet.  But then, do we add 802.11 -> 802.3
translation in the pcap library?