systemd and userdb discussion

f33dm3bits

Super Moderator
Staff member
Gold Supporter
Joined
Dec 11, 2019
Messages
10,070
Reaction score
8,949
Credits
73,926
This topic was started to create a separate technical discussion about systemd and userd, as they are related to the following topic where only the age laws are being discussed, I thought it would be good to discuss this specific technical aspect of systemd as well.
So only talk about systemd and userdb related things here.


@wizardfromoz I mentioned it there because even when discussing this it could get people to talk about the topic where I posted it because they are related: laws(cause) vs technology(effect) the about it. Here's the new topic about just systemd and userdb then with the most important parts quoted and it's still useful information.
I am with David - no entries result, on several of my Mints.



I am inclined to throw it out there that it is to do perhaps with PAM (Pluggable Authentication Module) activity to do with user-installed apps that Brian @Condobloke and Maarten @f33dm3bits have installed, whereas David and I have not.

An example could be a Password Manager such as Keepass.

That being said, that could be discussed elsewhere, so we do not derail this Thread, which is about Age Verification in Linux.

Cheers

Wizard
For those using systemD, you can run the following to disable the functionalities that were merged into SystemD for the Age fields that were merged as those are the services which use it.

I have had these disabled for a while now and everything is still working fine.
If you do the following, you will see that the status is "inactive/dead".
Code:
systemctl status systemd-userdbd.socket
○ systemd-userdbd.socket
Loaded: masked (Reason: Unit systemd-userdbd.socket is masked.)
Active: inactive (dead)
I think it depends on what your system started out as. If the initial installation didn't include certain packages, and such packages weren't part of any dependency chain in subsequent upgrades, those packages wouldn't be included on the system. One would thus needed to have installed them separately I guess to have them. Updating and upgrading just upgrades packages that are already on the system, as well as any dependencies.

A quick check on AI suggests that Mint installer doesn't install systemd-userdb packages by default, so if they appear on a Mint system I guess they have been installed by the user or installed as a dependency.

Edit: just checked the list of packages on the installer here: https://github.com/linuxmint/mint-d...bian-live-13.0.0-cinnamon/filesystem.packages, and systemd-userdb does not appear.

Looking into what depends on systemd-userdbd on debian, only one package appears:
Code:
[~]$ apt rdepends systemd-userdbd
systemd-userdbd
Reverse Depends:
  Depends: systemd-homed (= 260.1-1)
  Recommends: libnss-systemd
  Suggests: systemd
I guess it's similar for Mint which I can't check at the moment.
It doesn't appear that pam or keepass would call in systemd-userdb, though the following is from debian rather than mint:
Code:
[~]$ apt rdepends libpam-systemd
libpam-systemd
Reverse Depends:
  Recommends: argyll
  Recommends: udisks2
  Recommends: systemd-sysv
 |Recommends: python3-jarabe
  Recommends: sddm
  Suggests: profile-sync-daemon
  Depends: pam-session-timelimit
  Recommends: openssh-server
  Depends: nix-setup-systemd
  Recommends: network-manager
 |Recommends: needrestart
  Suggests: lxsession
 |Depends: lightdm
  Suggests: tpm2daemon
  Suggests: gpg-agent
  Suggests: dirmngr
  Recommends: flatpak
  Depends: debian-cloud-images-packages
  Depends: dbus-user-session


[~]$ apt rdepends keepass2
keepass2
Reverse Depends:
  Depends: keepass2-doc (= 2.60+dfsg-1)
  Depends: keepass2-plugin-keepassrpc (>= 2.48)
  Depends: keepass2-plugin-hibpofflinecheck

There do not appear to be any dependencies either way between systemd-userdbd and either libpam-system or keepass2, so neither of the latter two appear to draw in the former.
Perhaps check out post #33 above to see if that makes sense.

When check which packages provides which file for the mentioned services I only see it being related to systemd.
Code:
pacman -F systemd-userdbd.service
core/systemd 259.1-1 [installed: 260.1-1]
    usr/lib/systemd/system/systemd-userdbd.service

pacman -F systemd-homed.service
core/systemd 259.1-1 [installed: 260.1-1]
    usr/lib/systemd/system/systemd-homed.service
 
Last edited:


this thread is a break off from the : age verification - Linux.org's official stance | This relates ONLY to Linux Mint.


@wizardfromoz & @osprey


to show which applications use Pluggable Authentication Modules (PAM), you can check the configuration files located in /etc/pam.d/, where each file corresponds to a service that utilizes PAM for authentication. Each file lists the PAM modules that are used by the respective application.

I simply double clicked /home ..... then on File system (LH side) the opened /etc as root.

Then navigated down to pam.d .....and double clicked to open

That displayed the below:
1775973493826.png


Someone with more knowledge than I can perhaps throw some light on the results ?, please.
 
@Condobloke I'm going to move this topic into the other one I created which is more general and about systemd and userdb related stuff which can include any distribution.
 
Oops, I see Brian has already referenced that above.

Should have gone to SpecSavers.
 
I confess, all this talk about about systemd utilities and system integration, etc, etc, is completely over my head.....and in my case - running Puppy - much of it simply doesn't apply to us.

However; coincidental or not, you guys may be interested in this YT video I've literally just this minute viewed. It is, I think, highly relevant to this discussion.....certainly from the point of view of UK users, at any rate.


It demonstrates how a system designed to include the 95% majority - Windows, MacOS, iOS, Android - ends up excluding the 5% minority - Linux, BSD - not through intent.....but purely through indifference (and the designers of these systems simply not giving a sh*t).

(That 5% never even factored-in to their plans. It generates almost zero revenue, so.....no incentive, y'see.)

There's mention of - and some description about - something called the 'aged' daemon.....what it's supposed to achieve, and how everybody else's indifference (AND Linux's own endless choices) means it doesn't really do what it's supposed to do.

In other words, the powers-that-be are effectively saying:-

"If these people can't be bothered to conform & use an 'official' operating system (and give us their hard-earned dosh!).....then they've only got themselves to blame." Or words to that effect...

Huh???!!??!?

:rolleyes::(


Mike. o_O
 
Last edited:
That is indeed wonderful news to hear !

(Now I'll go watch that video.....busy as a dog with two tails here today )
 
Someone with more knowledge than I can perhaps throw some light on the results ?, please.
If you next click to view the /etc/pam.d/common-session configuration file, you will see a systemd rerefence. The system manager needs to know the user sessions and that's where it's done. Whether that has a direct link to systemd-userdb I have not looked, but certainly it will.

To keep it simple, using systemd without it managing user sessions (e.g. querying user details like group memberships etc) is not feasible. That's a core task for the system manager. The applications depending on the library, as shown in the first half of this thread, will require something from it - not necessarily user details but also other systemd functionality. It would be extremely easy for any application shipping its own /etc/pam.d/ file to require a populated date field. Same applies for the distro in general. Not worth discussing really IMHO.

The only way around it would be systemd merging a patch to explicitly exclude quering date fields from the userdb other than it being blank, which could be a fun twist to this saga ("You must populate this date field to proceed! Pick one between the french revolution and the year 2037 - because we're not sure about 2038 bugs yet").
 
@Trml , thanks for that above ^^^. I am about to fall asleep.... will read it more thoroughly on my tomorrow. Hopefully my brain will have recovered sufficiently to take it in.
 
After doing some reading i am preparing for the worst and have moved away from using systemd. The worst being this might be small steps for more and more American surveillance that might make people accept it easier cause of the steps.

There already is fingerprinting going on with systemd (etc/machine-id) but i don't really know how many apps would use it and if it currently a issue. Think if your browser could read the id, even worse then from browser too websites. Could be the future or could not be.
 


Follow Linux.org

Members online


Top