usbhid-dump Man page

usbhid-dump(8) System Manager’s Manual usbhid-dump(8)

NAME

usbhid-dump – dump USB HID device report descriptors and streams

SYNOPSIS

usbhid-dump [OPTION]…

DESCRIPTION

usbhid-dump uses libusb to dump report descriptors and streams from HID
(human interface device) interfaces of USB devices. By default, it
dumps HID interfaces of all connected USB devices, but could be limited
to a subset of them, or to a single interface, using options.

NOTE: usbhid-dump detaches kernel drivers from the interfaces it dumps
and uses them exclusively, so no other program receives the input in
the meantime. The report descriptor dumping is instantaneous, but the
stream dumping continues until terminated with SIGINT (^C from the ter‐
minal) or a timeout expires.

If you accidentally start dumping a stream from the USB keyboard you
use to control the terminal, the system will stop receiving the input
and you won’t be able to terminate usbhid-dump. Just stop your input
and wait until the timeout expires. The stream dumping will stop, the
keyboard will be reattached to the kernel driver and you will regain
control.

The default stream dumping timeout is 60 seconds and could be changed
with the -t option.

OPTIONS

-h, –help
Output a help message and exit.

-v, –version
Output version information and exit.

-s, -a, –address=bus[:dev] Limit interfaces by bus number and device address. Both 1-255,
decimal. Zeroes match any bus or device.

-d, -m, –model=vid[:pid] Limit interfaces by device vendor and product IDs. Both 1-FFFF,
hexadecimal. Zeroes match any vendor or product.

-i, –interface=NUMBER
Limit interfaces by number (0-254), decimal. 255 matches any
interface.

-e, –entity=STRING
The entity to dump: either “descriptor”, “stream” or “all”. The
value can be abbreviated down to one letter. The default is
“descriptor”.

-t, –stream-timeout=NUMBER
Stream interrupt transfer timeout, ms. Zero means infinity. The
default is 60000 (60 seconds).

-p, –stream-paused
Start with the stream dump output paused.

-f, –stream-feedback
Enable stream dumping feedback: print a dot to stderr for every
transfer dumped.

SIGNALS
USR1/USR2
Pause/resume stream dump output.

OUTPUT FORMAT
usbhid-dump outputs dumps in chunks. Each chunk is separated by an
empty line and starts with the following header line:

BUS:DEVICE:INTERFACE:ENTITY TIMESTAMP

Here, BUS, DEVICE and INTERFACE are bus, device and interface numbers
respectively. ENTITY is either “DESCRIPTOR” or “STREAM”. TIMESTAMP is
timestamp in seconds since epoch.

After the header the actual dump data follows as hex bytes. A descrip‐
tor chunk includes the whole report descriptor. Every stream chunk
includes a whole report, usually, but if a report is bigger than end‐
point’s wMaxPacketSize, it will span several chunks.

EXAMPLES
Dump report descriptor for a device with address 3 on bus number 2:
usbhid-dump -a 2:3

Dump report stream for a device with vendor ID 0x5543 and product ID
0x0005:
usbhid-dump -m 5543:0005 -es

Dump report descriptor from interface 1 of a device with vendor ID
0x5543:
usbhid-dump -m 5543 -i 1 -ed

Dump report streams from all HID interfaces of all USB devices (cau‐
tion: you will loose control over the terminal if you use USB key‐
board):
usbhid-dump -es

AUTHOR

Nikolai Kondrashov

February 2012 usbhid-dump(8)