At the
2019
Embedded
Linux Conference North America, which was held in San Diego in August,
Krzysztof Opasiak gave a presentation on demystifying the ways to monitor—and
even change—USB traffic on a Linux system. He started with the basics of
the USB protocol and worked up into software and hardware tools to
observe, modify, and fuzz the messages that get sent. Those tools are part of the
arsenal that is available to those interested in looking deeply into USB.

Source: LWN.net – [$] The USB debugging arsenal