Hostap nl80211 - ath5 : WPA authentication + VLAN assignement

Jouni Malinen j
Thu Oct 22 09:41:17 PDT 2009

On Thu, Oct 22, 2009 at 06:23:08PM +0200, Maxence Dalmais wrote:

> I am unable to understand what happens, but just after the binding, my whole
> computer freeze (ie, I have to reboot).
> I don't know if the problem come from Hostap, the driver, or the kernel.

hostapd should not be able to freeze the computer (hang/crash the kernel
most likely), i.e., I would expect this to be an issue in the kernel
(ath5k or mac80211).

> The assignment to the VLAN seems to be OK, but the crash come just after.
> It looks like a packet arrived just after and make the server crash.

I have not tested this with ath5k, but the last time I tested, dynamic
VLAN setup was working without problems (I think that test was with
mac80211_hwsim as the driver).

> Another probleme that I notice is that the virtual interface created are
> named "wlan0.X_rename" . Whereas the hostap.vlan file specify "wlan0.X" (for
> example wlan0.5_rename instead of wlan0.5)
> The i802_set_sta_vlan function use the "wlan0.5" notation.
> Do you think that could be a part of the problem ? if yes, how to solve this
> ?

I would not expect this to be the cause for the hang. The interface is
not created as wlan0.X_rename; it is created as wlan0.X. Something else
in the system is renaming the interface afterwards. I don't know the
details of your system configuration, so I cannot be sure what is doing
this, but anyway, I would assume it is udev and its persistent net
rules. It should be possible to disable that somehow (google udev
persistent net rules for more info).

> Can somebody give me more information to help me to solve my problem ?

Have you seen any error messages from the kernel? I would suggest
running the test in text mode (i.e., with kernel messages showing up on
the console). That may be enough to get the needed information to figure
out which component is crashing.

Jouni Malinen                                            PGP id EFC895FA

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