[ath9k-devel] Group Key fix for VAPs

[ath9k-devel] Group Key fix for VAPs

[yingqiang Ma]

When I set up multiple VAPs with ath9k, I encountered an issue that
the traffic may be lost after a while.

The detailed phenomenon is
1. After a while the clients connected to one of these VAPs will get
into a state that no broadcast/multicast packets can be transfered
successfully while the unicast packets can be transfered normally.
2. Minutes latter the unitcast packets transfer will fail as well,
because the ARP entry is expired and it can't be freshed due to the
broadcast trouble.

It caused by the group key overwritten and someone discussed this
issue before, but haven't work out a fix yet.

I?referred?the method in madwifi, and made a patch for ath9k.
The method is to set the high bit of the sender(AP)'s address, and
associated that mac and the group key. It requires the hardware
supports multicast frame key search. It seems true for AR9160.

Not sure whether it's the correct way to fix this issue. But it seems
to work in my test. The patch is attached, feel free to revise it.


Regards & Thanks,
Daniel Ma
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[ath9k-devel] Group Key fix for VAPs

[Goo Mail]

Hi all,

On Thu, Apr 1, 2010 at 1:21 AM, yingqiang Ma <yma.cool@gmail.com> wrote:

> When I set up multiple VAPs with ath9k, I encountered an issue that
> the traffic may be lost after a while.
> [...]

I referred the method in madwifi, and made a patch for ath9k.
> The method is to set the high bit of the sender(AP)'s address, and
> associated that mac and the group key. It requires the hardware
> supports multicast frame key search. It seems true for AR9160.
>

I have been running with Daniel's patch for more than a week, and I wanted
to confirm that it has been working flawlessly for me (AR9280). I hope that
the devs consider this for inclusion in wireless-testing (if it's not
already in the queue, that is)! Without this (or some other) patch, multiple
VIFs on ath9k are basically unusable if you try to use encryption on more
than one of those VIFs.

Also, thanks to both Daniel and the mainline devs for all of your hard work
getting us this far!

Scott
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[ath9k-devel] Group Key fix for VAPs

[Luis R. Rodriguez]

On Fri, Apr 9, 2010 at 2:31 PM, Goo Mail <goomail59@gmail.com> wrote:
> Hi all,
> On Thu, Apr 1, 2010 at 1:21 AM, yingqiang Ma <yma.cool@gmail.com> wrote:
>>
>> When I set up multiple VAPs with ath9k, I encountered an issue that
>> the traffic may be lost after a while.
>> [...]
>>
>> I?referred?the method in madwifi, and made a patch for ath9k.
>> The method is to set the high bit of the sender(AP)'s address, and
>> associated that mac and the group key. It requires the hardware
>> supports multicast frame key search. It seems true for AR9160.
>
> I have been running with Daniel's patch for more than a week, and I wanted
> to confirm that it has been working flawlessly for me (AR9280). I hope that
> the devs consider this for inclusion in wireless-testing (if it's not
> already in the queue, that is)! Without this (or some other) patch, multiple
> VIFs on ath9k are basically unusable if you try to use encryption on more
> than one of those VIFs.
> Also, thanks to both Daniel and the mainline devs for all of your hard work
> getting us this far!
> Scott

The patch must be posted inline through the usual means:

http://wireless.kernel.org/en/developers/Documentation/SubmittingPatches

  Luis