Make descriptors available in usbmon backend

[FFY00]

I think one place this could really improve over Wireshark is by (optionally) having the descriptors in one tab/part of the frontend. Would this be something you are open to add?

[FFY00]

I realized this is only available on certain backends and is why it is not working with usbmon.

[Qyriad]

I don't think there's anything about the usbmon backend that means ViewSB can't show the descriptors—so long as it sees the GET_DESCRIPTOR request, and usbmon should be very capable of observing things at that high a level—so I think this might actually be a bug, but I'll need to look at it more.

Going to reopen this for now at least until I look at it probably next week.

[FFY00]

Actually in usbmon ViewSB could be proactive and go ask the kernel for the descriptors.

[Qyriad]

True, and if I recall correctly lsusb does that if it has the permissions (as opposed to asking the kernel for its stored descriptors), but at the least I wouldn't want ViewSB to do that automatically since that would affect the USB traffic, so ideally there would be a UI button to trigger it. But currently the frontend can't communicate to the backend. Frontend/analyzer/backend communication is something that's very desirable and planned (#39), but will take a non-trivial amount of work.

As for this issue: I'm seeing descriptors just fine on my machine with usbmon, unless you mean something different than "details" panel in this screenshot?

[mossmann]

@FFY00 Is the view shown above what you were looking for, or were you imagining a separate display that aggregates information from descriptors?

[FFY00]

Yes, though the issue title is outdated.

[martinling]

Closed in preparation for archiving the repository. We have replaced ViewSB with Packetry.