This part adds the documentation for the interface authorization. Signed-off-by: Stefan Koch <skoch@xxxxxxx> --- Documentation/ABI/testing/sysfs-bus-usb | 22 +++++++++++++++++++++ Documentation/usb/authorization.txt | 34 +++++++++++++++++++++++++++++++++ 2 files changed, 56 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index e5cc763..ca8c8d3 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -1,3 +1,25 @@ +What: /sys/bus/usb/devices/INTERFACE/authorized +Date: June 2015 +KernelVersion: 4.2 +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: June 2015 +KernelVersion: 4.2 +Description: + This is used as default value that determines + if interfaces would authorized per default. + The value can be 1 or 0. It is per default 1. + What: /sys/bus/usb/device/.../authorized Date: July 2008 KernelVersion: 2.6.26 diff --git a/Documentation/usb/authorization.txt b/Documentation/usb/authorization.txt index c069b68..020cec5 100644 --- a/Documentation/usb/authorization.txt +++ b/Documentation/usb/authorization.txt @@ -3,6 +3,9 @@ Authorizing (or not) your USB devices to connect to the system (C) 2007 Inaky Perez-Gonzalez <inaky@xxxxxxxxxxxxxxx> Intel Corporation +Interface authorization part: + (C) 2015 Stefan Koch <skoch@xxxxxxx> SUSE LLC + This feature allows you to control if a USB device can be used (or not) in a system. This feature will allow you to implement a lock-down of USB devices, fully controlled by user space. @@ -90,3 +93,34 @@ 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. -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
