Better way to manage /proc/bus/usb/* ownership?

[Kay Sievers]

On 7/8/07, Fryderyk Dziarmagowski <freetz at gmx.net> wrote:
> --- Jason Grant <expires07 at logular.com> wrote:
>
> > On a fresh install of fedora7, gthumb reports an error "cannot claim USB
> > device" when my camera is inserted. This is because the files
> > under /proc/bus/usb have only root privileges.
>
> isn't /dev/bus/usb/* accessing a prefered way? I don't even have usbfs
> mounted and I can access my camera over libusb without smallest
> problems (same for scanner).

Right, recent distros use /dev/bus/usb/ nodes managed by udev.
HAL/PolicyKit/ConsoleKit will grant/revoke access to usb devices by
adding/removing ACL's to nodes in /dev/bus/usb. The usbfs in /proc can
not be used, because it can't handle access control lists.

Any work in that area should improve HAL/PolicyKit/ConsoleKit
integration. Upstream HAL can not support hacks that change the
primary owner/group setting of device nodes. Fast-user-switching, or
sane handling of multiple user sessions is not possible that way.

Thanks,
Kay