[PATCH] Fix delayed EAPOL RX frames

[Hatano, Tomoharu (Sony Mobile)]

Hi Jouni,

I'm sorry to have kept you waiting long time.

After I confirmed from our log, it took around 110ms in worst case.
So, it looks 200ms is enough for fix.
And it may depend on the implementation of chip vendor.
Can we continue to discuss it if we change the timeout of the patch from 900ms to 200ms?

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11-19 16:16:20.704 D/wpa_supplicant( 1371): wlan0: RX EAPOL from c8:d7:19:da:8f:41
11-19 16:16:20.704 D/wpa_supplicant( 1371): RX EAPOL - hexdump(len=9): 02 00 00 05 01 00 00 05 01
11-19 16:16:20.704 D/wpa_supplicant( 1371): wlan0: Not associated - Delay processing of received EAPOL frame (state=COMPLETED bssid=c8:d7:19:da:8d:ed) 
*** Received 1st EAPOL frame
11-19 16:16:20.804 D/wpa_supplicant( 1371): nl80211: Event message available
11-19 16:16:20.804 D/wpa_supplicant( 1371): nl80211: Drv Event 47 (NL80211_CMD_ROAM) received for wlan0
11-19 16:16:20.804 D/wpa_supplicant( 1371): nl80211: Roam event
11-19 16:16:20.814 D/wpa_supplicant( 1371): nl80211: Associated on 2412 MHz
11-19 16:16:20.814 D/wpa_supplicant( 1371): nl80211: Associated with c8:d7:19:da:8f:41
*** Associated. (It took 110ms)
11-19 16:16:20.814 D/wpa_supplicant( 1371): nl80211: Operating frequency for the associated BSS from scan results: 2412 MHz
----------

Best Regards,
Tomoharu Hatano

-----Original Message-----
From: Hatano, Tomoharu (Sony Mobile) 
Sent: Friday, January 06, 2017 10:20 PM
To: Jouni Malinen <j at w1.fi>
Cc: hostap at lists.infradead.org; Sogo, Shinji (Sony Mobile) <Shinji.Sogo at sonymobile.com>; Nanbu, Tomonori (Sony Mobile) <Tomonori.Nanbu at sonymobile.com>; Hatano, Tomoharu (Sony Mobile) <Tomoharu.Hatano at sonymobile.com>
Subject: RE: [PATCH] Fix delayed EAPOL RX frames

Hi Jouni,

I'm sorry for the late reply.
Please give me more time to confirm it.

Best Regards,
Tomoharu Hatano

-----Original Message-----
From: Jouni Malinen [mailto:j at w1.fi]
Sent: Sunday, December 18, 2016 5:51 AM
To: Hatano, Tomoharu (Sony Mobile) <Tomoharu.Hatano at sonymobile.com>
Cc: hostap at lists.infradead.org; Sogo, Shinji (Sony Mobile) <Shinji.Sogo at sonymobile.com>; Nanbu, Tomonori (Sony Mobile) <Tomonori.Nanbu at sonymobile.com>; Andrejs Cainikovs <andrejs.cainikovs at sonymobile.com>
Subject: Re: [PATCH] Fix delayed EAPOL RX frames

On Sat, Dec 17, 2016 at 06:29:17PM +0900, Tomoharu Hatano wrote:
> Increase EAPOL RX frame timeout from 100 to 900 ms.
> This will fix occasional roaming and authentication disconnects on EAP 
> networks.

Would you happen to have a debug log with timestamps showing such a case where this change helps? It is somewhat surprising if it can take 900 ms for the kernel to deliver association event after it has delivered an EAPOL frame from that association. This optimization handling for pending EAPOL frame is really there only to work around the possibility of those kernel event getting reordered.

In addition, it would be interesting know how lack of this workaround would result in disconnection. I would expect the AP/Authenticator to try again if it does not receive a response. If this workaround is neede to avoid a disconnection (i.e., to do something else than just speed up the connection a bit by avoiding retry), it would seem to indicate that something else is broken in the network or frame processing..
 
-- 
Jouni Malinen                                            PGP id EFC895FA