Re: Sniffing/Protocol problems
From: Omesh Tickoo (omesht_at_yahoo.com)
Date: 2002-07-24 22:25:15 UTC
Thanks Jouni,
That does explain it. Its not critical for my work to
understand how the AP handles WEP but seeing the
different behavior of different cards made me ask the
question.
I am trying to introduce a content sensitive
scheduling policy at the hostap. Specifically I plan
to introduce a couple of new management frame
types(using reserved FC fields) and add a scheduler at
the hostap. I was going through the source and at one
point I thought of modifying hostapd for introducing
the scheduler. But after checking the code thoroughly
I am not sure if that is a good idea. For one, I might
not be able to test my scheduler unless I change the
hostapd to use actual applications for data transfer.
Am I wrong in saying this? I make this statement
beacuse all hostapd does to the recieved data is
report it. I am not sure if there is any processing of
the recieved data going on (I couldnt get it running
because it gave me an ioctl error on the existence of
wlan0 though it was UP).
I did see some previous postings where folks were
involved in adding additional management frame formats
to hostapd. If anyone has an experience to share, it
will be a great help.
regards
-omesh
- Jouni Malinen <jkmaline_at_cc.hut.fi> wrote:
> On Wed, Jul 24, 2002 at 10:28:24AM -0700, Omesh
> Tickoo wrote:
>
> > 3. When I replace the STA card with Cisco aironet
> card
> > and use the airo_cs driver, I see that "iwconfig
> eth0"
> > does not report an access point (or it reports
> > 44:44:44:44:44:44 for the access point) if the WEP
> > keys dont match with the HostAP running on a
> nearby
> > laptop.
>
> Cisco card is probably using shared key
> authentication, which used WEP
> to generate challenge-response style authentication.
>
> > The behavior is different when I use Linksys cards
> > with hostap_cs in managed mode for the STA.
> Regardless
> > of whether the WEP keys match or not, the STA
> reports
> > the HostAP MAC as its access point. Of course, I
> can
> > ping between the two machines only if the WEP keys
> are
> > same. Any ideas about which of the two behaviors
> is
> > correct? The Cisco card with airo_cs or the
> Linksys
> > card with hostap_cs.
>
> hostap_cs.o uses the default authentication mode as
> a station. It is
> open system authentication that does not use WEP at
> all. It is thus able
> to authenticate and associate with the AP even with
> incorrect WEP keys.
> Host AP in Master mode allows both authentication
> algorithms as default,
> but it is also possible to configure it to accept
> only open system or
> shared key authenticationi (prism2_param wlan0
> ap_auth_algs <val>).
>
> --
> Jouni Malinen
> PGP id EFC895FA
>
Do You Yahoo!?
Yahoo! Health - Feel better, live better
http://health.yahoo.com
This archive was generated by
hypermail 2.1.4.