[cups-devel] USB Printing Standard

Hello everyone,

I'm currently working on creating a virtual USB printer to use for testing
purposes.

I'm using USBIP
<https://github.com/torvalds/linux/tree/master/tools/usb/usbip> which
allows me to share my virtual printer over the network, as well as mocking
a physical connection locally.

I've managed to get it working with most of the basic USB messages defined
in the USB Printer Class Specification
<http://www.usb.org/developers/docs/devclass_docs/usbprint11a021811.pdf> and
can configure the printer using CUPS.

I'm having some trouble with handling actual print jobs however. I can
receive parts of the document, but CUPS fails with the error "Unable to
send data to printer".

Is there any documentation which explains the expected exchange of messages
during a basic USB print job?

Thanks,
David