On Wed, 2007-10-10 at 09:43 +0200, Holger Schurig wrote:
> > > Yes, with a HZ/4 rate.
> >
> > I don't care how _fast_ it tries to reassociate. I care that
> > it doesn't give up after some amount of time.
>
> And I don't want that the driver get's stuck after some arbitrary
> time. *NO OTHER DRIVER* that I know of get's stuck. The current
> libertas code has actually a built-in denial of service attack.
>
> Libertas isn't just used in the OLPC, where can make sure some
> userspace tools does the job. I'll using libertas in PDA like
I have personally used it on platforms that are !OLPC. Please don't
assume that I only care about libertas on OLPC.
> devices, which used to have some HERMES I or HERMES II chips and
> have to switch to some other CF card because you can't buy CF
> cards with those chips any more. And on those device you can't
> just arbitrarily change the rest of the firmware.
>
> So, at least in the no encryption & WEP obfuscation mode a WLAN
> driver should work without special user space software, because
> that's how real-life dictates the operation.
I won't throw a hissy fit over the reassociation patch as long as it
only tries this in open & WEP situations where a supplicant is not
necessary. That means you cannot simply requeue an association in
libertas_mac_event_disconnected(), but you should check the association
request and not requeue if:
1) the assoc request's mode is ad-hoc (is there a point to retrying
assoc in adhoc?)
2) the assoc request has secinfo->WPAenabled || secinfo->WPA2enabled
3) the assoc request has WPA mcast or unicast keys set
4) the assoc request has a wpa_ie_len > 0
so in libertas_mac_event_disconnected() it should to be something like
the following:
if (adapter->pending_assoc_req) {
if (test_bit(ASSOC_FLAG_MODE, &assoc_req->flags))
if (assoc_req->mode != IW_MODE_INFRA)
goto done;
if (test_bit(ASSOC_FLAG_SECINFO, &assoc_req->flags))
if (assoc_req->secinfo.WPAenabled ||assoc_req->secinfo.WPA2enabled)
goto done;
if (test_bit(ASSOC_FLAG_WPA_MCAST_KEY, &assoc_req->flags))
if (assoc_req->wpa_mcast_key.len)
goto done;
if (test_bit(ASSOC_FLAG_WPA_UCAST_KEY, &assoc_req->flags))
if (assoc_req->wpa_ucast_key.len)
goto done;
if (test_bit(ASSOC_FLAG_WPA_IE, &assoc_req->flags))
if (assoc_req->wpa_ie_len > 0)
goto done;
cancel_delayed_work(&priv->assoc_work);
queue_delayed_work(priv->work_thread,
&priv->assoc_work, HZ / 4);
done:
;
}
Dan
> And, as said, otherwise you have a denial of service scenario.
>
>
> > That's fine. The drivers should _not_ be trying to handle all
> > roaming cornercases themselves.
>
> Either the driver or the firmware should handle all corner cases.
> With a HERMES II chip and a wlags49_h2_cs.ko driver, I can
> nicely roam with WPA+wpa_supplicant, and also with plain WEP
> (and no wpa_supplicant).
>
> I see no technical reason why libertas shouldn't be able to do
> the same and behave like all other FULLMAC drivers.
>
>
> > Userspace must come into the equation at some point, especially
> > with WPA!!
>
> I don't see that userspace *MUST* come into the equation at some
> point. If it *WISHES* to come into the equation: nothing hinders
> it. Running "iwevent" while killing the station at the AP yields
> these events:
>
> 10:38:43.139777 eth1 New Access Point/Cell
> address:Not-Associated
> 10:38:43.389217 eth1 Scan request completed
> 10:38:45.161671 eth1 New Access Point/Cell
> address:00:1B:53:11:E2:B0
>
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