QMI via MBIM for "FCC Authentication" fix

Bjørn Mork bjorn at mork.no
Wed Jul 29 13:54:00 PDT 2015


Collin McMillan <cmc at nd.edu> writes:

> Hi Folks
>
> I have been continuing to look at this -- it's a really interesting problem
> and library!  Before I dive into libqmi, I'm trying to make it work for a
> specific case in libmbim.  I'm just trying to make a program that sends QMI
> messages to the QMI-over-MBIM service.
>
> If I understand correctly, all I need to do is send a message like this one:
>
> 03 00 00 00 40 00 00 00 04 00 00 00 01 00 00 00 00 00 00 00 D1 A3 0B C2 F9
> 7A 6E 43 BF 65 C7 E2 4F B0 F0 D3 01 00 00 00 01 00 00 00 10 00 00 00 01 0C
> 00 00 02 01 00 01 00 5F 55 00 00 00 00 00
>
> Checking the spec (http://caxapa.ru/thumbs/334029/MBIM_v1_0_USBIF_FINAL.pdf),
> that means:
>
> 03 00 00 00: MessageType, 3 for command, see table 9.1 in the above PDF
> 40 00 00 00: MessageLength, 64 bytes
> 04 00 00 00: TransactionID, libmbim picked this for me
>
> 01 00 00 00 00 00 00 00: FragmentHeader (table 9.3)
> D1 ... D3: 16 bytes for the service UUID
> 01 00 00 00: CID, I believe this has to be 1 because 1 is the only CID
> listed as possible on this service (see my output of mbimcli -d
> /dev/cdc-wdm0 --query-device-services in an above email)
> 01 00 00 00: 1 for a SET operation (table 9-6 in the spec PDF)
> 10 00 00 00: InformationBufferLength, 16 bytes
> 01 0C...end: InformationBuffer
>
> Then InformationBuffer is the QMI message.  In this case, I sent:
> 01 0C 00 00 02 01 00 01 00 5F 55 00 00
>
> I got this from running:
> qmicli -d /dev/cdc-wdm0 --dms-set-fcc-authentication -v --client-cid=1
> This command fails, but it does output the raw data sent to the device,
> using the verbose flag.
>
>
> Anyway, what I have now is:
> 1) A modified version of libmbim 1.12.2 that includes a new service called
> QMIOVER.  I can send all the gory details, but essentially it is just a new
> data/json service file, and several appropriate changes to libmbim e.g. to
> mbim-cid.h/c and mbim-uuid.h/.c.
>
>     //
> *********************************************************************************
>     { "type" : "Service",
>       "name" : "QMI Over" },
>
>   //
> *********************************************************************************
>   { "name"     : "qmi",
>     "service"  : "QMIOver",
>     "type"     : "Command",
>     "set"    : [ { "name"       : "QmiMsg",
>                      "format"     : "byte-array",
>                      "array-size" : "16" } ],
>     "response" : [ { "name"       : "QMUX",
>                      "format"     : "byte-array",
>                      "array-size" : "65" } ] }
>
>
> 2) A pretty ugly stripped down version of mbimcli, that just opens the
> device, tries to send a QMI allocate CID message, then the FCC message, and
> the closes the device.  Here's the relevant output of that program (same a
> mbimcli's verbose output):
>
> [29 Jul 2015, 16:06:01] -Error ** mbim_cid_get_printable: assertion
> 'service > MBIM_SERVICE_INVALID' failed
> [29 Jul 2015, 16:06:01] [Debug] [/dev/cdc-wdm0] Received message
> (translated)...
>>>>>>> Header:
>>>>>>>   length      = 72
>>>>>>>   type        = command-done (0x80000003)
>>>>>>>   transaction = 3
>>>>>>> Fragment header:
>>>>>>>   total   = 1
>>>>>>>   current = 0
>>>>>>> Contents:
>>>>>>>   status error = 'None' (0x00000000)
>>>>>>>   service      = 'invalid' (d1a30bc2-f97a-6e43-bf65-c7e24fb0f0d3)
>>>>>>>   cid          = '(null)' (0x00000001)
>
> [29 Jul 2015, 16:06:01] [Debug] Asynchronously sending QMI test message...
> [29 Jul 2015, 16:06:01] [Debug] [/dev/cdc-wdm0] Sent message...
> <<<<<< RAW:
> <<<<<<   length = 64
> <<<<<<   data   =
> 03:00:00:00:40:00:00:00:04:00:00:00:01:00:00:00:00:00:00:00:D1:A3:0B:C2:F9:7A:6E:43:BF:65:C7:E2:4F:B0:F0:D3:01:00:00:00:01:00:00:00:10:00:00:00:01:0C:00:00:02:01:00:01:00:5F:55:00:00:00:00:00
>
> [29 Jul 2015, 16:06:01] -Error ** mbim_cid_get_printable: assertion
> 'service > MBIM_SERVICE_INVALID' failed
> [29 Jul 2015, 16:06:01] [Debug] [/dev/cdc-wdm0] Sent message (translated)...
> <<<<<< Header:
> <<<<<<   length      = 64
> <<<<<<   type        = command (0x00000003)
> <<<<<<   transaction = 4
> <<<<<< Fragment header:
> <<<<<<   total   = 1
> <<<<<<   current = 0
> <<<<<< Contents:
> <<<<<<   service = 'invalid' (d1a30bc2-f97a-6e43-bf65-c7e24fb0f0d3)
> <<<<<<   cid     = '(null)' (0x00000001)
> <<<<<<   type    = 'set' (0x00000001)
>
> [29 Jul 2015, 16:06:01] [Debug] [/dev/cdc-wdm0] Received message...
>>>>>>> RAW:
>>>>>>>   length = 48
>>>>>>>   data   =
> 03:00:00:80:30:00:00:00:04:00:00:00:01:00:00:00:00:00:00:00:D1:A3:0B:C2:F9:7A:6E:43:BF:65:C7:E2:4F:B0:F0:D3:01:00:00:00:02:00:00:00:00:00:00:00
>
> [29 Jul 2015, 16:06:01] -Error ** mbim_cid_get_printable: assertion
> 'service > MBIM_SERVICE_INVALID' failed
> [29 Jul 2015, 16:06:01] [Debug] [/dev/cdc-wdm0] Received message
> (translated)...
>>>>>>> Header:
>>>>>>>   length      = 48
>>>>>>>   type        = command-done (0x80000003)
>>>>>>>   transaction = 4
>>>>>>> Fragment header:
>>>>>>>   total   = 1
>>>>>>>   current = 0
>>>>>>> Contents:
>>>>>>>   status error = 'Failure' (0x00000002)
>>>>>>>   service      = 'invalid' (d1a30bc2-f97a-6e43-bf65-c7e24fb0f0d3)
>>>>>>>   cid          = '(null)' (0x00000001)
>
> (BTW, I am not sure why the mbim_cid_get_printable function gives an error
> here -- I have added the service macros, etc., everywhere I can find)
>
> Yes, this is a serious hack job at this point, but I am wondering if you
> could tell me if I'm on the right track here. :-)  It seems that I *can*
> communicate with the QMI interface, but that the FCC message is failing for
> some reason.  It could be that I am allocating the CID improperly, or that
> the FCC message is improperly formatted, or that I am missing some other
> step.
>
> Once I wrap my mind completely around the problem, I'm going take your
> suggestion and combine it with libqmi.  Then, modify qmicli so that I can
> run arbitrary QMI commands over MBIM.
>
>
> Thanks again!

The above looks basically fine to me.  I cannot see any obvious reason
why it fails.  But it's an MBIM failure, so I don't think it's related
to the actual QMI message.  There's probably some weird formatting
thing missing.

I do notice that you send a 16 byte InfoBuffer with a zero-padded 13
byte QMI message.  Maybe that doesn't work?

FWIW, here's a transaction sequence I used when I briefly tested this a
month ago.  As you can see, I used the exact QMI message length for the
MBIM InfoBuffer:


MBIM OPEN:
01 00 00 00 10 00 00 00 01 00 00 00 00 10 00 00 

MBIM OPEN_DONE:
01 00 00 80 10 00 00 00 01 00 00 00 00 00 00 00 

CTL 0x0022 request:
03 00 00 00 40 00 00 00 05 00 00 00 01 00 00 00 00 00 00 00 d1 a3 0b c2 f9 7a 6e 43 bf 65 c7 e2 4f b0 f0 d3 01 00 00 00 01 00 00 00 10 00 00 00 01 0f 00 00 00 00 00 04 22 00 04 00 01 01 00 02

CTL 0x0022 response:
03 00 00 80 48 00 00 00 05 00 00 00 01 00 00 00 00 00 00 00 d1 a3 0b c2 f9 7a 6e 43 bf 65 c7 e2 4f b0 f0 d3 01 00 00 00 00 00 00 00 18 00 00 00 01 17 00 80 00 00 01 04 22 00 0c 00 02 04 00 00 00 00 00 01 02 00 02 34

DMS 0x555b request:
03 00 00 00 3d 00 00 00 07 00 00 00 01 00 00 00 00 00 00 00 d1 a3 0b c2 f9 7a 6e 43 bf 65 c7 e2 4f b0 f0 d3 01 00 00 00 01 00 00 00 0d 00 00 00 01 0c 00 00 02 34 00 06 00 5b 55 00 00 

DMS 0x555b response:
03 00 00 80 5d 00 00 00 07 00 00 00 01 00 00 00 00 00 00 00 d1 a3 0b c2 f9 7a 6e 43 bf 65 c7 e2 4f b0 f0 d3 01 00 00 00 00 00 00 00 2d 00 00 00 01 2c 00 80 02 34 02 06 00 5b 55 20 00 02 04 00 00 00 00 00 10 01 00 13 11 12 00 11 06 07 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 14 15 16

CTL 0x0023 request:
03 00 00 00 41 00 00 00 09 00 00 00 01 00 00 00 00 00 00 00 d1 a3 0b c2 f9 7a 6e 43 bf 65 c7 e2 4f b0 f0 d3 01 00 00 00 01 00 00 00 11 00 00 00 01 10 00 00 00 00 00 08 23 00 05 00 01 02 00 02 34

CTL 0x0023 response:
03 00 00 80 48 00 00 00 09 00 00 00 01 00 00 00 00 00 00 00 d1 a3 0b c2 f9 7a 6e 43 bf 65 c7 e2 4f b0 f0 d3 01 00 00 00 00 00 00 00 18 00 00 00 01 17 00 80 00 00 01 08 23 00 0c 00 02 04 00 00 00 00 00 01 02 00 02 34

MBIM CLOSE
02 00 00 00 0c 00 00 00 0a 00 00 00 

MBIM CLOSE_DONE
02 00 00 80 10 00 00 00 0a 00 00 00 00 00 00 00 



Bjørn


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