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mkkot

Member

From: Poland

Registered: 2009-12-20

Posts: 288

ACLs not applied on device by udev on user login

Hi all,
so there is a usb scanner:

Bus 001 Device 003: ID 055f:021e Mustek Systems, Inc. BearPaw 1200 TA/CS

and a logged in user, registered in loginctl:

[mk@linux ~]$ loginctl session-status
1 - mk (1000)
           Since: Sat 2020-10-24 09:57:45 CEST; 8s ago
          Leader: 530 (lxdm-session)
            Seat: seat0; vc1
             TTY: tty1
         Service: lxdm; type x11; class user
           State: active
            Unit: session-1.scope
                  ├─530 /usr/lib/lxdm/lxdm-session
                  ├─539 xfce4-session
                  ├─625 /usr/bin/ssh-agent -s
                  ├─630 xfwm4
[...]

The scanner device file should have ACLs enabled for my user, so I can use the scanner:

getfacl  /dev/bus/usb/001/003
getfacl: Removing leading '/' from absolute path names
# file: dev/bus/usb/001/003
# owner: root
# group: scanner
user::rw-
user:mk:rw- <<<<<<<< HERE
group::rw-
mask::rw-
other::r--

It comes from the fact that udev runs following rules on this device:

udevadm info --query=path --name=/dev/bus/usb/001/003
/devices/pci0000:00/0000:00:02.1/0000:01:00.0/usb1/1-6

udevadm test  /devices/pci0000:00/0000:00:02.1/0000:01:00.0/usb1/1-6
[...]
Reading rules file: /usr/lib/udev/rules.d/49-sane.rules
# Mustek BearPaw 1200 CS | Mustek BearPaw 1200 TA
ATTRS{idVendor}=="055f", ATTRS{idProduct}=="021e", MODE="0664", GROUP="scanner", ENV{libsane_matched}="yes"
[...]
Reading rules file: /usr/lib/udev/rules.d/70-uaccess.rules
# SCSI and USB scanners
ENV{libsane_matched}=="yes", TAG+="uaccess"

Reading rules file: /usr/lib/udev/rules.d/73-seat-late.rules
TAG=="uaccess", ENV{MAJOR}!="", RUN{builtin}+="uaccess"
[...]

DEVPATH=/devices/pci0000:00/0000:00:02.1/0000:01:00.0/usb1/1-6
DEVNAME=/dev/bus/usb/001/003
DEVTYPE=usb_device
DRIVER=usb
PRODUCT=55f/21e/100
[...]
ACTION=add
[...]
ID_MODEL_FROM_DATABASE=BearPaw 1200 TA/CS
[...]
run: '/bin/sh -c 'if test -e /sys//devices/pci0000:00/0000:00:02.1/0000:01:00.0/usb1/1-6/power/control; then echo on > /sys//devices/pci0000:00/0000:00:02.1/0000:01:00.0/usb1/1-6/power/control; elif test -e /sys//devices/pci0000:00/0000:00:02.1/0000:01:00.0/usb1/1-6/power/level; then echo on > /sys//devices/pci0000:00/0000:00:02.1/0000:01:00.0/usb1/1-6/power/level; fi''
run: 'uaccess' <<< HERE ACLs should be applied
Unload module index
Unloaded link configuration context.

The problem is that after the boot and login the permissions look like that:

getfacl  /dev/bus/usb/001/003
getfacl: Removing leading '/' from absolute path names
# file: dev/bus/usb/001/003
# owner: root
# group: scanner
user::rw-
group::rw-
other::r--

There is no user mk with write access and the scanner is not detected.

If I run:

sudo udevadm trigger -c add /dev/bus/usb/001/003

Then the permissions are set correctly:

getfacl  /dev/bus/usb/001/003
getfacl: Removing leading '/' from absolute path names
# file: dev/bus/usb/001/003
# owner: root
# group: scanner
user::rw-
user:mk:rw- << IT IS HERE AS IT'S SUPPOSED TO BE
group::rw-
mask::rw-
other::r--

The same happens if I physically replug the device.

The question is why it doesn't happen automatically on user login?

DeletedUser210826

Banned

Registered: 2020-02-01

Posts: 70

Re: ACLs not applied on device by udev on user login

Hello,

I am not sure if it's related to this, but I have an udev rule to disable mouse wakeup:

ACTION=="add", SUBSYSTEM=="usb", ATTRS{idVendor}=="046d", ATTRS{idProduct}=="c534", ATTR{power/wakeup}="disabled"

It doesn't work when the system boots, but it does if I replug the device. Is there any solution to this ?

mkkot

Member

From: Poland

Registered: 2009-12-20

Posts: 288

Re: ACLs not applied on device by udev on user login

This is the solution:
https://gitlab.com/sane-project/backend … quests/541

DeletedUser210826

Banned

Registered: 2020-02-01

Posts: 70

Re: ACLs not applied on device by udev on user login

Thanks for the quick reply.

I tried to use ACTION!="remove" but it doesn't work anyway. Is there something else I should do ?

mkkot

Member

From: Poland

Registered: 2009-12-20

Posts: 288

Re: ACLs not applied on device by udev on user login

ACTION=="remove":
https://gitlab.com/marcin2006/backends/ … 20a70a3185

Last edited by mkkot (2020-12-06 10:19:56)

DeletedUser210826

Banned

Registered: 2020-02-01

Posts: 70

Re: ACLs not applied on device by udev on user login

ACTION=="remove":
https://gitlab.com/marcin2006/backends/ … 20a70a3185

In that case it does not work, and obviously it stops working in case of replug.

Thanks for the help anyway.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,231

Re: ACLs not applied on device by udev on user login

davc0n you seem to have a different issue, which is why the confusion arises.

I'd say try ACTION=="add|change" if that doesn't help, I suggest you open a new thread for your issue.

mkkot

Member

From: Poland

Registered: 2009-12-20

Posts: 288

Re: ACLs not applied on device by udev on user login

Yes, I was living in a conviction that davc0n is having a problem with a scanner.
@V1del the ACTION!="remove" is recommended because ACTION=="add|change" does not include "bind" action (and I think few others).

About the mouse rule, just guessing but I would try:

ACTION!="remove", SUBSYSTEM=="usb", ATTRS{idVendor}=="046d", ATTRS{idProduct}=="c534"

DeletedUser210826

Banned

Registered: 2020-02-01

Posts: 70

Re: ACLs not applied on device by udev on user login

davc0n you seem to have a different issue, which is why the confusion arises.

I'd say try ACTION=="add|change" if that doesn't help, I suggest you open a new thread for your issue.

Agree, we are definately off topic. I guess ACTION!="remove" includes this, and didn't work.

Thanks for the help though.