USB problem: /dev/ugen* dynamically auto-reconfigures to root:operator 644, so non-root user unable to access USB devices even if wanted

[Andreas Klemm]

Hi,

have severe problems accessing usb devices as non-root user.
In this case a Canon Powershot G5 camera.

I want to download pics from my digicam using digikam application
as user "andreas".

The devices that are being used by digikam:
root at titan[ttyp2]{57} ~ lsof | grep digikam | grep /dev
digikam   1755    root    0u  VCHR        5,2     0t19646     110 /dev/ttyp2
digikam   1755    root    1u  VCHR        5,2     0t19646     110 /dev/ttyp2
digikam   1755    root    2u  VCHR        5,2     0t19646     110 /dev/ttyp2
digikam   1755    root   15u  VCHR     114,16         0t0     128 /dev/ugen1
digikam   1755    root   16r  VCHR     114,17      0t7817     131 /dev/ugen1.1
digikam   1755    root   17r  VCHR     114,19        0t16     133 /dev/ugen1.3

Running digikam with SUID root bit turned on doesn't work.
  andreas at titan[ttyp4]{1032} ~ digikam
  The KDE libraries are not designed to run with suid privileges.

Changing the permissions on /dev/ugen1* doesn't work either since

- even _if_ the devices are present after turning camera on and
- even _if_ permissions of /dev/ugen1 /dev/ugen1.1 ... 1.3 are
  being changed successfully to 666

the devices seems to be on the 1st access dynamically recreated,
since the permissions suddenly are *re-set* to root 644 automagically
after the 1st access of the digikam application as user.

To sum up: as normal user I'm unable to connect to the USB camera.

Is there a more generic approach to be able to use USB
devices as non-root user, that I overlooked up to now ?

	Andreas ///

-- 
Andreas Klemm - Powered by FreeBSD 5.1-CURRENT
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