[sane-devel] reverse engineering / usbsnoop
Sat, 11 Sep 2004 18:36:47 +0200
Mbosowo I Sampson wrote:
> After reading reams of documentation, I think I have a grasp on how the
> USB protocol works. I started snooping the usb traffic of my hp scanjet
> 3970 so I can start writing the backend for it. I have a couple of
> With Snoopy Pro it seems to stop logging information once the actual
> scan begins. Someone else posted something on SF page about it stopping
> once the bulk transfer began. I was wondering if anyone knew how to get
> around this. I tried sniffit, but the documentation says it only works
> for NT 2000.
I think you're hitting a nice point there:
it's a bit unclear what _the_ tool for USB sniffing currently is
(at least to me).
I tried the following programs:
sniffusb 0.12 and 0.13. http://www.wingmanteam.com/usbsnoopy/
+ logs in text format (for easy perl processing).
- does not work with windows xp
- chokes sometimes on large USB bulk
All perl scripts that I have seen were made to parse the format of the
logs created by this program.
usb snoopy pro. http://sourceforge.net/projects/usbsnoop/
- logs in binary format (-> no further discussion necessary)
sniff-bin . http://benoit.papillault.free.fr/usbsnoop/
This program looks similar to sniffusb
+ logs in plain text (although slightly different format from sniffusb)
+ works under windows xp
If I were to reverse engineer a protocol again, I think I would
> I was looking at a usb dump,
> posted by this guy,
> On this page he says that the chipset he was looking at had 244
> registers. How exactly can you tell that by the logs?
I'm not sure, I don't think you can tell that from the log.
According to the text, USB transfers starting with 0x80 and 0x88
indicate register get/set. Perhaps he counted all unique register
> I'm looking at the logs, and I'm not sure where to start. I was to start
> simple by writing a stand alone application that tuns on the lamp, then
> build on it from there. I have a session log, but I have no idea how to
> find out what register and values are needed to turn on the lamp. Any tips?
Is the protocol similar to the one used in the hp4400/4470?
Can you post a link to your log?
> I wanted to post the Snoopypro log here, but apprently its a binary
> file. I tried to use usb-robot to control the scanner from linux, its
> not working, and there doesn't seem to be any documentation on usb-robot
> anywhere. lovely.
I think usb-robot is not compatible with the snoopypro logs.