[PATCH v2 2/2] AP: Set STA's assoc flag in the driver before sending assoc. resp.

[Jouni Malinen]

On Mon, Jan 25, 2016 at 12:29:20PM +0200, Ilan Peer wrote:
> Previously stations were added to the driver only after the association
> response is acked. In the time period between the station has acked the
> association response and between the time the station was added to the
> kernel, the station can already start sending data frames, which will be
> dropped by the HW. In addition to the data loss, the driver may ignore
> NDPs with PM bit set from this STA.
> 
> Fix this by setting/adding the STA with associated flag set to the
> driver before the AP sends the association response with status success.
> If the association response wasn't acked, remove the station from
> the driver.

This is not compliant with the IEEE 802.11 standard. The station becomes
associated when it acknowledges the (Re)Association Response frame. At
minimum, the proposed behavior here could result in protocol compliance
test cases failing since the AP would accept Class 3 frames before the
non-AP STA has received or ACK'ed the (Re)Association Response frame.

It would be better to add the associated flag in the driver (or
mac80211) to allow this to be implemented in standards compliant manner.
At minimum, the commit log here would need to explain why the proposed
behavior with the STA-removal-on-error (no ACK) is justifiable
workaround and why it would not result in any worse issues than
potential protocol compliance test case failures in practice.

I did some cleanup to these two patches (including splitting the first
one into two). The attached patches show the current state of the
patches in my temporary branch. Please use them as the starting point
for any possible resubmission of the changes. For now, I'm dropping
these from my queue until this protocol compliance issue is resolved.

-- 
Jouni Malinen                                            PGP id EFC895FA
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