Using ath10k for WiFi capturing non-11ac traffic

Amato Carbonara acarbonara13 at gmail.com
Thu Apr 16 06:16:21 PDT 2015


Also confirmed from my captures.  No AMPDU frames captured using
ath10k driver.  Using another WiFi adapter and driver, AMPDU frames
were captured.

On Wed, Apr 15, 2015 at 3:34 PM, Ben Greear <greearb at candelatech.com> wrote:
> Here's another funny thing I just noticed.
>
> When trying to capture high-speed IBSS traffic, I get almost no data packets
> at all delivered...maybe because the are A-MPDU or something like that and are
> too big?
>
> Anyway, curious if you have tried high-speed captures in networks with block-ack
> and a-mpdu enabled....
>
> Thanks,
> Ben
>
>
> On 04/15/2015 08:46 AM, Amato Carbonara wrote:
>> Thanks Ben. I plan to upgrade to latest ath10k firmware and retest. I need to find some time to experiment.
>>
>> On Apr 15, 2015 11:41 AM, "Ben Greear" <greearb at candelatech.com <mailto:greearb at candelatech.com>> wrote:
>>
>>     On 04/15/2015 08:07 AM, Amato Carbonara wrote:
>>     > Hi Ben,
>>     >   I performed my captures when the WiFi adapter running the ath10k was
>>     > not connected to the WiFi network.  In other words, the capture shows
>>     > traffic between 2 different devices.  The ath10k device is in
>>     > promiscuous mode and capturing all the traffic between the devices.
>>
>>     Yes, I did the same, and still no BlockAck action frames are captured.
>>
>>     Firmware has special handling for these frames, so probably it eats
>>     them before passing on to the host.
>>
>>     Thanks,
>>     Ben
>>
>>     >
>>     > On Wed, Apr 15, 2015 at 10:58 AM, Ben Greear <greearb at candelatech.com <mailto:greearb at candelatech.com>> wrote:
>>     >>
>>     >>
>>     >> On 04/15/2015 07:28 AM, Amato Carbonara wrote:
>>     >>>
>>     >>> Hi Ben,
>>     >>>    I have done numerous captures using the ath10k driver on different
>>     >>> 802.11 variant networks, specifically 802.11n (20MHz and 40MHz) and
>>     >>> 802.11ac.  In all these captures, I have captured the Block-Ack frames
>>     >>> (Wireshark filter wlan.fc.type_subtype == 0x0019), but do not see any
>>     >>> Block-ACK Request or Response frames.  In fact, none of my captures
>>     >>> using the ath10k drivers show any Action frames (Wireshark filter
>>     >>> wlan.fc.type_subtype == 0x000d).  This is very peculiar since the IEEE
>>     >>> specification 802.11-2012 section 9.21.2 states: "If the intended
>>     >>> recipient STA is capable of participating, the originator sends an
>>     >>> ADDBA Request frame".  Therefor, the ADDBA must be sent in order for
>>     >>> Block-Acks to occur.  I have also noticed missing Association Response
>>     >>> frames from the STA.
>>     >>>
>>     >>> Currently, I am using firmware 10.1.467.2-1 to perform my captures.
>>     >>
>>     >>
>>     >> I think the ath10k firmware must just consume the block-ack request/response
>>     >> frames internally and
>>     >> never send them up to the host.  It does send an htt message about blockack
>>     >> control messages being
>>     >> received.
>>     >>
>>     >> Probably something I could fix in my 10.1 firmware...but first I need to
>>     >> figure out why ath9k (mac80211 stack, actually) ignores the block-ack
>>     >> messages that my ibss ath10k
>>     >> interface sends....
>>     >>
>>     >> Thanks,
>>     >> Ben
>>     >>
>>     >>
>>     >>>
>>     >>> Has anyone else tried using a different firmware version, for example
>>     >>> 10.2.4, to perform WiFi captures?
>>     >>>
>>     >>> On Tue, Apr 14, 2015 at 8:19 PM, Ben Greear <greearb at candelatech.com <mailto:greearb at candelatech.com>>
>>     >>> wrote:
>>     >>>>
>>     >>>> Out of curiosity, have you been able to capture Action frames
>>     >>>> (specifically,
>>     >>>> block-ack add/del frames) with ath10k?  I just wasted a large amount of
>>     >>>> time wondering
>>     >>>> why the frames are not seen...but ath9k monitor port sees them just fine.
>>     >>>>
>>     >>>> Thanks,
>>     >>>> Ben
>>     >>>>
>>     >>>>
>>     >>>> On 04/14/2015 11:04 AM, Amato Carbonara wrote:
>>     >>>>>
>>     >>>>> Hello Michal,
>>     >>>>>    I was able to decrypt all traffic types (11a, 11n at 20MHz, 11n at
>>     >>>>> 40MHz and 11ac at 80MHz) using the 10.1.467.2-1 firmware on the
>>     >>>>> QCA9880 chipset.  The problem was not with Wireshark.  I had to
>>     >>>>> install backports for the at10k drivers to make it work.  Procedures
>>     >>>>> are documented here:
>>     >>>>> https://wireless.wiki.kernel.org/en/users/Drivers/ath10k/backports
>>     >>>>>
>>     >>>>> Thank you for your help,
>>     >>>>> Amato
>>     >>>>>
>>     >>>>> On Tue, Apr 14, 2015 at 1:38 AM, Michal Kazior <michal.kazior at tieto.com <mailto:michal.kazior at tieto.com>>
>>     >>>>> wrote:
>>     >>>>>>
>>     >>>>>> On 6 April 2015 at 21:49, Amato Carbonara <acarbonara13 at gmail.com <mailto:acarbonara13 at gmail.com>>
>>     >>>>>> wrote:
>>     >>>>>>>
>>     >>>>>>> Hello,
>>     >>>>>>>    I have installed a WiFi adapter with the Qualcomm-Atheros QCA-9880
>>     >>>>>>> chipset using the at10k drivers.  I am using this WiFi adapter to
>>     >>>>>>> capture WLAN traffic.  The recommended firmware for capturing WiFi
>>     >>>>>>> traffic is 10.1.467.2-1 per the website.  See following link:
>>     >>>>>>> https://wireless.wiki.kernel.org/en/users/drivers/ath10k/monitor
>>     >>>>>>
>>     >>>>>>
>>     >>>>>> Generally the 10.x line is preferred for sniffing. You could also try
>>     >>>>>> 10.2.4.
>>     >>>>>>
>>     >>>>>>
>>     >>>>>>> I have successfully installed the above firmware and have been using
>>     >>>>>>> the adapter/driver to capture and decrypt all 802.11ac traffic.
>>     >>>>>>> However, I have noticed some strange behavior when trying to decrypt
>>     >>>>>>> other types of traffic such as:
>>     >>>>>>>    1) 802.11a = not able to decrypt any traffic
>>     >>>>>>>    2) 802.11n at 20MHz = able to decrypt only partial traffic
>>     >>>>>>>    3) 802.11n at 40MHz = able to decrypt only partial traffic
>>     >>>>>>>
>>     >>>>>>> I have tried using the different "iw" and "iwconfig" commands to set
>>     >>>>>>> the frequency and channel bandwidth (for example, iw dev wlan1 set
>>     >>>>>>> freq 5180 HT20).  Has anyone else seen this issue of not being able to
>>     >>>>>>> decrypt all/some of the WiFi traffic?
>>     >>>>>>
>>     >>>>>>
>>     >>>>>> `iwconfig` is an old program. You shouldn't use it. Just stick with
>>     >>>>>> `iw`.
>>     >>>>>>
>>     >>>>>> To decrypt traffic you need to see keying handshake (both after
>>     >>>>>> association and later for each rekeying). If sniffer misses that you
>>     >>>>>> won't be able to decipher data either from the start or you'll stop
>>     >>>>>> being able to decrypt multicast data after GTK rekeying.
>>     >>>>>>
>>     >>>>>> Another thing is I've had numerous random problems with wireshark
>>     >>>>>> refusing to decrypt frames reliably. I recall some older version would
>>     >>>>>> get stuck and need the key configuration (in preferences window) to be
>>     >>>>>> re-applied or the decrypt checkbox to be re-checked. YMMV.
>>     >>>>>>
>>     >>>>>>
>>     >>>>>> Michał
>>     >>>>>
>>     >>>>>
>>     >>>>> _______________________________________________
>>     >>>>> ath10k mailing list
>>     >>>>> ath10k at lists.infradead.org <mailto:ath10k at lists.infradead.org>
>>     >>>>> http://lists.infradead.org/mailman/listinfo/ath10k
>>     >>>>>
>>     >>>>
>>     >>>>
>>     >>>> --
>>     >>>> Ben Greear <greearb at candelatech.com <mailto:greearb at candelatech.com>>
>>     >>>> Candela Technologies Inc  http://www.candelatech.com
>>     >>>>
>>     >>>
>>     >>> _______________________________________________
>>     >>> ath10k mailing list
>>     >>> ath10k at lists.infradead.org <mailto:ath10k at lists.infradead.org>
>>     >>> http://lists.infradead.org/mailman/listinfo/ath10k
>>     >>>
>>     >>
>>     >> --
>>     >> Ben Greear <greearb at candelatech.com <mailto:greearb at candelatech.com>>
>>     >> Candela Technologies Inc  http://www.candelatech.com
>>     >
>>
>>
>>     --
>>     Ben Greear <greearb at candelatech.com <mailto: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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