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author | Stefan Koch <stefan.koch10@gmail.com> | 2015-08-25 22:10:10 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-09-22 22:08:40 +0300 |
commit | 7f59c150ad9ae017abcff16775ccdd0bdefb963d (patch) | |
tree | 790d93be49f94dfb80b445159b122b67d62c090a /Documentation/usb | |
parent | 310d2b4124c073a2057ef9d952d4d938e9b1dfd9 (diff) | |
download | linux-7f59c150ad9ae017abcff16775ccdd0bdefb963d.tar.xz |
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>
Diffstat (limited to 'Documentation/usb')
-rw-r--r-- | Documentation/usb/authorization.txt | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/Documentation/usb/authorization.txt b/Documentation/usb/authorization.txt index c069b6884c77..c7e985f05d8f 100644 --- a/Documentation/usb/authorization.txt +++ b/Documentation/usb/authorization.txt @@ -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. |