Wi-Fi Access Point Powered by Hostapd Sends Malformed Packets to 65th Client

Ben Greear greearb at candelatech.com
Tue Jun 19 15:41:48 PDT 2018


On 06/19/2018 03:32 PM, Ben Greear wrote:
> On 06/19/2018 01:59 PM, Daniel Miess wrote:
>> Hi Ben,
>>
>> The Wi-Fi module in question is using a QCA9880 chipset. The driver is Ath10k on the 3.14.28 kernel with some backports. The firmware is v10.1 of the Candela
>> Tech Ath10k firmware.
>
> I would suggest trying to reproduce this with a recent stock kernel (4.16 or 4.17), stock QCA firmware, and stock hostapd.
>
> You can do this in a PC with the 9880 NIC in it, so no special backports or other
> board-specific stuff will be needed.
>
> If the problem persists in stock code, then it would be worth looking more closely at the
> hostapd (and since you would be using stock code and normal hardware, others could
> probably reproduce the same problem for debugging).
>
> If the problem does not persist with stock code, then you can try introducing the
> ath10k-ct driver and/or firmware in a controlled manner to see if they are at fault.

And, FYI, we just ran a test with the 9880 chip on our 4.13.16+ kernel, with our ath10k-ct
10.1 firmware, and we can get 126 stations associated with no problems.  Our hostapd
includes the patches you bisected to.

We were using our own wifi-station emulator to be the stations, and our hardware
is different and so forth, so there could still be problems that we do not see
for whatever reason.

Thanks,
Ben


>
> Thanks,
> Ben
>
>
>>
>> Thanks,
>> Daniel
>>
>> -----Original Message-----
>> From: Ben Greear <greearb at candelatech.com>
>> Sent: Tuesday, June 19, 2018 9:34 AM
>> To: Daniel Miess <DMiess at sierrawireless.com>; hostap at lists.infradead.org
>> Subject: Re: Wi-Fi Access Point Powered by Hostapd Sends Malformed Packets to 65th Client
>>
>> On 06/19/2018 08:44 AM, Daniel Miess wrote:
>>> Hello Everyone,
>>>
>>> I am debugging an issue I have with an access point powered by Hostapd. Hostapd was built with the default defconfig configuration and is using a Wi-Fi card
>>> which uses Ath10k drivers. I am running a test where I attempt to connect 128 clients to an access point running on the card in rapid succession. I am able
>>> to connect 64 clients to the card in about 6 or 7 seconds but once the 65th client is reached the process stalls. Responses from the access point to
>>> authentication requests from this client are malformed, being sent out with incorrect frame check sequences. I do not encounter this issue when running
>>> hostapd 2.5 but observe it with 100% reproducibility on version 2.6 as well as the latest git master branch. By bisecting I was able to narrow down my issue
>>> to a pair of commits: dc55b6b & bb598c3. These commits are seeking to "Add support for full station state operations".
>>>
>>> Is there someone familiar with the work done in these check-ins who can comment on why I might be seeing this behavior and what I might be able to do to work
>>> around it?
>>
>> ath10k behavior is significantly impacted by what firmware, driver, and chipset it is using, so please let us know what versions of those components you are
>> using.
>>
>> Thanks,
>> Ben
>>
>>>
>>> Thanks,
>>> Daniel
>>>
>>>
>>> _______________________________________________
>>> Hostap mailing list
>>> Hostap at lists.infradead.org
>>> http://lists.infradead.org/mailman/listinfo/hostap
>>>
>>
>>
>> --
>> Ben Greear <greearb at candelatech.com>
>> Candela Technologies Inc  http://www.candelatech.com
>>
>
>


-- 
Ben Greear <greearb at candelatech.com>
Candela Technologies Inc  http://www.candelatech.com




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