WLAN: current status and new bits of weirdness

Werner Almesberger werner at openmoko.org
Thu Feb 19 05:38:48 CET 2009

I wrote:
> - sometimes, the key exchange of wpa_supplicant fails, causing
>   indefinite attempts to associate.

It can actually affect all communication, not only the key
exchange. The following sequence yields this failure within a
small number of tries:

- start wpa_supplicant -d and wait until it has authentiated,
  e.g., when it displays

- get a lease with dhclient

- kill wpa_supplicant and restart it (don't kill dhclient)

The clearest indicator that you "have it" is when wpa_supplicant
keeps on trying to do the key exchange (run it with -d or -dd),
with the AR6k associating and deassociating all the time.

Through which states exactly wpa_supplicant loops depends on when
we start failing to transmit. If it happens after the initial
handshake, we may loop in the group key exchange. If it happens
before we do anything else, we may loop in the 4-way handshake or
even the AP scan.

The symptoms are very similar to what happens when the AR6k
module crashes, but we may be lucky enough that it is a driver
bug this time.

- Werner

More information about the devel mailing list