monitoring USB bus for devices

Hi All!

I’m trying to write a driver that will monitor USB bus and when some
device is attached to a specific hub, I want to replace vendor ID and
model ID of this device by some constant, To do this, I want to
catch a first Get Device Descriptor sent to the device.

Do i need a class filter driver to catch this or usb bus(Hub) upper filter?

Also is it possible to I monitor usb device enumeration process from userland?

Thanks
-Subodh