xsane fails to find scanner

[Richard Kleeman]

In hardy (1/7/08) xsane reports no scanner as ordinary user. As root the scanner is located. This bug has occurred previously when it was a permissions setting issue generated by udev

[Richard Kleeman (kleeman)]

The file

/etc/udev/rules.d/45-libsane.rules

which SHOULD be in libsane is missing on my hardy system. This would explain this bug.

[Richard Kleeman (kleeman)]

I found this in the changelog for sane-backends

* Do not install the udev rules, since hal now provides dynamic ACLs on
    device nodes. (See hardy-hardware-detection spec.)
  * debian/libsane.postinst: Do not create the scanner group.
  * debian/libsane.postinst: Remove obsolete udev rules on upgrade.

So hal should be handling this and isn't at present. Added hal as an affected package

[der_vegi (m-may)]

Also confirmed here on Hardy amd64 with all updates applied until today. 'sane-find-scanner' does find the scanner, 'scanimage -L' does not. But root can use it. This used to work a couple of weeks ago...

[Richard Kleeman (kleeman)]

Since there is no longer a scanner group and the file

/etc/udev/rules.d/40-permissions.rules

sets the permissions of /dev/bus/usb (and subdirectories) to be 0664
this means only root (the group now for usb scanners?) can access the device for writing.

If Scott Remnant the maintainer of udev is reading this could he comment on my confusion here ;-) ;-)

[Scott James Remnant (Canonical) (canonical-scott)]

Right, and then HAL should add ACLs to those devices such that console users can use them -- that's probably what's not working here?

[Richard Kleeman (kleeman)]

Yes it appears so Scott. I am assuming that this part of the new hardy hardware hardware spec is where something is amiss:

"Drop the default system groups plugdev and scanner. Enable ConsoleKit support in hal, which assigns read/write permission to removable USB devices with dynamic ACLs."

Taken from

https://wiki.ubuntu.com/DesktopTeam/Specs/HardyHardwareDetection

[Scott James Remnant (Canonical) (canonical-scott)]

Can you provide the output of "uname -a" to confirm which kernel you're running?

[Richard Kleeman (kleeman)]

Upgraded to the latest kernel and the problem remains. The 'uname -a' output is:

Linux ubuntu 2.6.24-4-generic #1 SMP Mon Jan 14 18:19:11 UTC 2008 x86_64 GNU/Linux

[der_vegi (m-may)]

Still present with Linux tux 2.6.24-5-generic #1 SMP Thu Jan 24 19:29:14 UTC 2008 x86_64 GNU/Linux .

[Clay Weber (claydoh)]

And still present in
2.6.24-7-generic #1 SMP Thu Feb 7 01:29:58 UTC 2008 i686 GNU/Linux

[mikko (mikko-)]

Same problem, 2.6.24-7-generic, Brother DCP-7010 printer/scanner

Duplicates?
https://bugs.launchpad.net/ubuntu/+source/sane-backends/+bug/180794
https://bugs.launchpad.net/ubuntu/+source/sane-backends/+bug/188552

[Shaji N V (nvshaji)]

Changing the permissions in :

/etc/udev/rules.d/40-permissions.rules

to 0666 for usb and usb_device and restarting the udev solves the problem, but does it have any side effects?

[Richard Kleeman (kleeman)]

Yes I have tried the permissions change as well and it works. Two problems: An ordinary
user should not face this. Those permissions may potentially pose a security issue in some situations.

[Assid (assid)]

Still waiting on this, bug. It seems xsane can find it no problems, but you need to set the permissions via chmod

Any chance this will be fixed?

[Guillaume (bou-gui)]

Pb is solved on my laptop since a few days, without changing any permissions.

[canucked (canucked)]

Same problem. Linux 2.6.24-12-generic #1 SMP Wed Mar 12 23:01:54 UTC 2008 i686 GNU/Linux. Using HP Laserjet 3055 printer/scanner.