usb: interface authorization: Documentation part
This part adds the documentation for the interface authorization. Signed-off-by: Stefan Koch <stefan.koch10@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
310d2b4124
commit
7f59c150ad
|
@ -1,3 +1,23 @@
|
|||
What: /sys/bus/usb/devices/INTERFACE/authorized
|
||||
Date: August 2015
|
||||
Description:
|
||||
This allows to authorize (1) or deauthorize (0)
|
||||
individual interfaces instead a whole device
|
||||
in contrast to the device authorization.
|
||||
If a deauthorized interface will be authorized
|
||||
so the driver probing must be triggered manually
|
||||
by writing INTERFACE to /sys/bus/usb/drivers_probe
|
||||
This allows to avoid side-effects with drivers
|
||||
that need multiple interfaces.
|
||||
A deauthorized interface cannot be probed or claimed.
|
||||
|
||||
What: /sys/bus/usb/devices/usbX/interface_authorized_default
|
||||
Date: August 2015
|
||||
Description:
|
||||
This is used as value that determines if interfaces
|
||||
would be authorized by default.
|
||||
The value can be 1 or 0. It's by default 1.
|
||||
|
||||
What: /sys/bus/usb/device/.../authorized
|
||||
Date: July 2008
|
||||
KernelVersion: 2.6.26
|
||||
|
|
|
@ -90,3 +90,34 @@ etc, but you get the idea. Anybody with access to a device gadget kit
|
|||
can fake descriptors and device info. Don't trust that. You are
|
||||
welcome.
|
||||
|
||||
|
||||
Interface authorization
|
||||
-----------------------
|
||||
There is a similar approach to allow or deny specific USB interfaces.
|
||||
That allows to block only a subset of an USB device.
|
||||
|
||||
Authorize an interface:
|
||||
$ echo 1 > /sys/bus/usb/devices/INTERFACE/authorized
|
||||
|
||||
Deauthorize an interface:
|
||||
$ echo 0 > /sys/bus/usb/devices/INTERFACE/authorized
|
||||
|
||||
The default value for new interfaces
|
||||
on a particular USB bus can be changed, too.
|
||||
|
||||
Allow interfaces per default:
|
||||
$ echo 1 > /sys/bus/usb/devices/usbX/interface_authorized_default
|
||||
|
||||
Deny interfaces per default:
|
||||
$ echo 0 > /sys/bus/usb/devices/usbX/interface_authorized_default
|
||||
|
||||
Per default the interface_authorized_default bit is 1.
|
||||
So all interfaces would authorized per default.
|
||||
|
||||
Note:
|
||||
If a deauthorized interface will be authorized so the driver probing must
|
||||
be triggered manually by writing INTERFACE to /sys/bus/usb/drivers_probe
|
||||
|
||||
For drivers that need multiple interfaces all needed interfaces should be
|
||||
authroized first. After that the drivers should be probed.
|
||||
This avoids side effects.
|
||||
|
|
Loading…
Reference in a new issue