USB: make usbdevices export their device nodes instead of using a separate class
o The "real" usb-devices export now a device node which can
populate /dev/bus/usb.
o The usb_device class is optional now and can be disabled in the
kernel config. Major/minor of the "real" devices and class devices
are the same.
o The environment of the usb-device event contains DEVNUM and BUSNUM to
help udev and get rid of the ugly udev rule we need for the class
devices.
o The usb-devices and usb-interfaces share the same bus, so I used
the new "struct device_type" to let these devices identify
themselves. This also removes the current logic of using a magic
platform-pointer.
The name of the device_type is also added to the environment
which makes it easier to distinguish the different kinds of devices
on the same subsystem.
It looks like this:
add@/devices/pci0000:00/0000:00:1d.1/usb2/2-1
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1d.1/usb2/2-1
SUBSYSTEM=usb
SEQNUM=1533
MAJOR=189
MINOR=131
DEVTYPE=usb_device
PRODUCT=46d/c03e/2000
TYPE=0/0/0
BUSNUM=002
DEVNUM=004
This udev rule works as a replacement for usb_device class devices:
SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \
NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644"
Updated patch, which needs the device_type patches in Greg's tree.
I also got a bugzilla assigned for this. :)
https://bugzilla.novell.com/show_bug.cgi?id=250659
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig
index 2fc0f88..f493fb1 100644
--- a/drivers/usb/core/Kconfig
+++ b/drivers/usb/core/Kconfig
@@ -31,7 +31,30 @@
For the format of the various /proc/bus/usb/ files, please read
<file:Documentation/usb/proc_usb_info.txt>.
- Most users want to say Y here.
+ Usbfs files can't handle Access Control Lists (ACL), which are the
+ default way to grant access to USB devices for untrusted users of a
+ desktop system. The usbfs functionality is replaced by real
+ device-nodes managed by udev. These nodes live in /dev/bus/usb and
+ are used by libusb.
+
+config USB_DEVICE_CLASS
+ bool "USB device class-devices (DEPRECATED)"
+ depends on USB
+ default n
+ ---help---
+ Userspace access to USB devices is granted by device-nodes exported
+ directly from the usbdev in sysfs. Old versions of the driver
+ core and udev needed additional class devices to export device nodes.
+
+ These additional devices are difficult to handle in userspace, if
+ information about USB interfaces must be available. One device contains
+ the device node, the other device contains the interface data. Both
+ devices are at the same level in sysfs (siblings) and one can't access
+ the other. The device node created directly by the usbdev is the parent
+ device of the interface and therefore easily accessible from the interface
+ event.
+
+ This option provides backward compatibility if needed.
config USB_DYNAMIC_MINORS
bool "Dynamic USB minor allocation (EXPERIMENTAL)"