[wpa_supplicant] IBSS/RSN

[SJB89@Drexel.edu]

I have found a process by which it is possible to create/join a three-node
IBSS using RSN - however, I'm not sure if it is the result of a bug within
wpa_supplicant.  Is there a simpler way of accomplishing this?

My wpa_supplicant.conf (initially), using wpa_supplicant 0.7.2 is:
ctrl_interface=DIR-/var/run/wpa_supplicant GROUP=wheel
ap_scan=2
network={
    ssid="swat"
    mode=1
    frequency=2412
    proto=RSN
    key_mgmt=WPA-PSK
    pairwise=NONE
    group=CCMP
    psk=1234567890
}

Setup:
1. sudo service NetworkManager stop
2. sudo ifconfig eth1 up 192.168.1.12x/24
3. sudo pkill wpa

Process:
1. Run wpa_supplicant -dd -K -i eth1 -c
/etc/wpa_supplicant/wpa_supplicant.conf -D wext
2. Run wpa_cli
      At this point, wpa_supplicant should be associating with a BSSID and
then disassociating roughly ten seconds later due to an association timeout.
3. With both wpa_supplicant and wpa_cli still running, modify
wpa_supplicant.conf so that key_mgmt=WPA-PSK is replaced by
key_mgmt=WPA-NONE, and save the file.
4. Within wpa_cli, run "reconfigure"
      After a scan, wpa_supplicant should associate with a BSSID and not
time out.  This connection will remain stable until wpa_supplicant is
killed.

In order for a node B to join the IBSS that was previously created by node
A, the above process must be completed, with the additional requirement that
the modification of wpa_supplicant.conf and "reconfigure" of wpa_supplicant
must occur while B's wpa_supplicant is associated with the same BSSID with
which A is associated, but before B's association times out.  If B's
association does time out, wpa_supplicant and wpa_cli must both be killed on
node B, wpa_supplicant.conf must return to its initial state as
key_mgmt=WPA-PSK, and the entire process must begin again.

It is important to note that wpa_supplicant can not be started with
key_mgmt=WPA-NONE - this results in a persistent loop of scans and no
attempted associations.  The above-detailed process does work for three
nodes, but is very cumbersome to apply.  Even if I write a bash script that
parses the output of wpa_supplicant and wpa_cli, edits wpa_supplicant.conf
at the right time, and issues 'wpa_cli reconfigure,' there seems to be a bit
of luck involved with getting three nodes on the same IBSS.  Is there a bug
somewhere within the code for WPA-PSK or WPA-NONE that is preventing me from
simply starting wpa_supplicant with key_mgmt=WPA-NONE, or is there an easier
way to achieve a three-node IBSS using RSN?

System configuration:
HP tc4200 with Intel PRO/Wireless 2200 802.11b/g mini-pci adapter
    (ipw2200 driver version 3.1)
wpa_supplicant v0.7.2 compiled from source with the following options in
.config:
    CONFIG_DRIVER_RALINK=y
    CONFIG_DRIVER_WEXT=y
    CONFIG_CTRL_IFACE=y
    CONFIG_BACKEND=file
    CONFIG_DEBUG_FILE=y
    CONFIG_WPA_TRACE=y
Fedora 13 (x86)
Linux kernel 2.6.33.6-147.2.4

Thank you for your continued support.
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