Delay processing of EAPOL frames when not associated

Jouni Malinen j at w1.fi
Tue Sep 8 03:05:40 EDT 2009


On Tue, Sep 08, 2009 at 09:23:18AM +0900, Masashi Honma wrote:

> I have reported an EAPOL frame problem.
> http://lists.shmoo.com/pipermail/hostap/2009-June/019848.html
> 
> Your recent commit [Delay processing of EAPOL frames when not associated] solved it.

Nice to hear that! The race condition between the EAPOL frame reception
and association event handling has been a known problem for a long time.
I finally added some workaround code for it after getting confident
enough that it would not cause problems for most drivers. Just dropping
the frame (like your patch did) would probably be fine, too, and the
delayed processing version is just an optimized way of that to remove
extra latency in case the AP does not retransmit the EAPOL frame
quickly.

The actual effect of the issue depended quite a bit on which driver and
which driver interface was used. For example, using nl80211 on Linux
recovered fine from the reordered events while using WEXT did not.

-- 
Jouni Malinen                                            PGP id EFC895FA


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