Re: DLT_ request

[Guy Harris <guy () alum mit edu>]

On Dec 11, 2016, at 8:12 AM, Scott Deandrea <sdeandrea () apple com> wrote:

> The bcdVersion field is interpreted as described by the bcdUSB field of the standard device descriptor in section 
> 9.6.1:
> The bcdUSB field contains a BCD version number. The value of the bcdUSB field is 0xJJMN for version JJ.M.N (JJ – 
> major version number, M – minor version number, N – sub-minor version number), e.g., version 2.1.3 is represented 
> with value 0x0213 and version 2.0 is represented with a value of 0x0200.

The bcdUSB field in section 9.6.1 "Device" appears to be the version of the USB specification that the device supports. 
 Is that the case?

If so, is the bcdVersion field also a USB specification version number, or is it a version number of the USB-over-BPF 
protocol, using the same 0xJJMN syntax as the USB specification version number in bsdUSB?

> Yes, for every USB request issued by the host there’s a kAppleUSBHostPacketFilterRequestSubmit packet emitted at 
> request time and a kAppleUSBHostPacketFilterRequestComplete packet emitted when the request completes with the same 
> ioID value.  For control endpoints, the submit packet also contains the setup data.  For all other endpoint types, 
> the submit packet is only this header.  The complete packet contains any data that was transferred.

So that's the case both if the host is sending data to the device and if the host is receiving data from the device - 
the complete packet has the data?
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