wpa_suuplicant(8) & wlan(4) vs. an(4) et al.

[David Wolfskill]

A while back (Jan 2006, at the latest), I perceived a need to set up my
wireless NIC in a way appropriate to the environment in which we found
ourselves.  Others have done this in various ways; I cobbled up a Perl
script that has received various tweaks over the years, but which has
worked reasonably well for wide-open environments and for those where
WEP is used.

I recently had occasion to use my laptop in an environment that used
WPA2; my script doesn't cope with that, and as wpa_supplicant(8) is in
base, I figured I'd merely switch to using it, and I could quit tweaking
my script & its associated data files.

That turns out to have been ... a bit overoptimistic.  (And
"overoptimism" isn't usually part of my self-image.  Having been in
sysadmin-type positions for over 3 decades tends to damp such
tendencies, at best.)

The types of (wireless) NICs I presently have available are an(4),
iwi(4), and wi(4).  The  an(4) devices are PCMCIA form factor; the
others are miniPCI.  (I have a wi(4) PCMCIA card, but I've never got it
to work -- not that doing so has been a priority.)

Now, I read the entry about wlan(4) cloning in /usr/src/UPDATING
(20080420).  And I'm aware that wi(4) only works for me in RELENG_6,
as it stopped associating after the 802.11 overhaul just before
RELENG_7 was branched from HEAD.  (I track each of RELENG_6, RELENG_7,
and HEAD on my laptop, usually on a daily basis; each gets a separate
slice.  This message is mostly about HEAD; I refer to RELENG_*
merely asa a point of reference.)

After building & booting today's CURRENT:

g1-37(8.0-C)[4] uname -a
FreeBSD g1-37.catwhisker.org 8.0-CURRENT FreeBSD 8.0-CURRENT #827: Wed Oct  8 06:09:16 PDT 2008     root at g1-37.catwhisker.org:/common/S4/obj/usr/src/sys/CANARY  i386
g1-37(8.0-C)[5] 

while using the an(4) device as configured by my script, I decided to
try wpa_supplicant(8) once again.  (There were no changes in src for
either RELENG_6 or RELENG_7 since yesterday, so I had a bit more time
than usual before heading in to work.)

Now yesterday, I had tweaked the startup routine used by my script to
pay attention & check to see if wpa_supplicant(8) was running; if so,
the startup script would merely exit.  That way, I wouldn't need to mess
with the script's execution bits or other ugly stuff if I wanted to
experiment with wpa_supplicant(8).

So I edited /etc/rc.conf to include:

g1-37(8.0-C)[5] grep an0 /etc/rc.conf
wlans_an0=wlan0
ifconfig_wlan0="WPA DHCP"
g1-37(8.0-C)[6] 

and to ensure a clean start, I rebooted the machine.

I was mildly surprised, then, to see my script get started anyway.
(Note: my script doesn't know a thing about wlan(4) or cloning; it uses
the an(4) device, and it appears to manage to get the NIC properly
associated, then invokes dhclient(8) & steps out of the way.)

Checking back on the consle log I saw:

n0: wlan_clone_create: reject, not an 802.11 device
ifconfig: SIOCIFCREATE2: Device not configured
Starting wpa_supplicant.
/etc/rc.d/wpa_supplicant: WARNING: failed to start wpa_supplicant
Starting Network: lo0.
xl0: link state changed to DOWN
an0: wlan_clone_create: reject, not an 802.11 device
ifconfig: SIOCIFCREATE2: Device not configured
Starting wpa_supplicant.
/etc/rc.d/wpa_supplicant: WARNING: failed to start wpa_supplicant
lock order reversal:

Hmmm....  "reject, not an 802.11 device" seems a bit harsh, given:

g1-37(8.0-C)[7] ifconfig an0
an0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        ether 00:40:96:40:5d:44
        inet 172.17.1.37 netmask 0xffff0000 broadcast 172.17.255.255
        media: IEEE 802.11 Wireless Ethernet autoselect (DS/11Mbps)
        status: associated
        ssid  1:lmdhw-net channel 6 (2437 Mhz 11b)
        stationname FreeBSD
        authmode OPEN privacy ON deftxkey 1 txpower 0 rtsthreshold 0
        fragthreshold 0 bmiss 0 ucastrate 0 mcastrate 0 mgmtrate 0 maxretry 0
        roaming DEVICE bintval 0
g1-37(8.0-C)[8] 

but I expect that's merely an artifact of an(4) not having been
overhauled to the new(er) wlan(4) framework or some such thing.  (Though
I could well be completely wrong about this, as I confess I've not
actually looked at the code in a long time.)

(Rather off-topic, but I did manage to get wpa_supplicant(8) to
work in RELENG_7 using WPA2 (though contrary to the man page, I was
unable to specify that protocol in wpa_supplicant.conf), but only
using the iwi(4) device -- and it would lose connectivity with
maddening frequency during the period I was trying to use it.  I
was also able to get wpa_supplicant(8) to associate using a small access
point I carry in my laptop bag, but I have not been able to get it to
associate at home (where I use WEP).  Weird.)

I'm not enough of a hacker to overhaul a device driver, but I am willing
(as some here might attest) to test patches & report back.

I wouldn't mind being able to delete my script -- while retaining my
ability to have network connetivity.  :-}

Peace,
david
-- 
David H. Wolfskill				david at catwhisker.org
Depriving a girl or boy of an opportunity for education is evil.

See http://www.catwhisker.org/~david/publickey.gpg for my public key.
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