Why does pipewire depend on it? Otherwise I'd just remove it right now.
A GUI sudo if you will, with XML and javascript code for its configuration files.
I'm not near my computer, but I would guess pipewire (as it usually runs within the users session) might rely on it to access the sound hardware without needing to run as root. But just guessing.
https://wiki.debian.org/PolicyKit
PolicyKit is an application-level toolkit for defining and handling the policy
that allows unprivileged processes to speak to privileged processes, in order to
grant some user the right to perform some tasks in some situations. It is
sometimes referred to as "the sudo of systemd".
Sample uses:
Let the user Hibernate and shutdown the computer.
Let the user manage (Wireless) connections.
Let the user mount/eject a removable media (CD/DVD, USB keys...)
Let the user access devices, like audio, scanner, etc.
"This is better than groups and setgid processes, because it means someone can't log in over ssh and mess with another user at the console." - Because that's what desktop users are really concerned about. We need more complexity because somebody might hax0r my desktop over SSH.
And, wow, they really actually did use XML as their configuration:
<match action="org.freedesktop.hal.storage.mount-fixed">
<match user="davidz">
<return result="yes"/>
</match>
<match user="freddy">
<return result="no"/>
</match>
</match>
How many groups do you think there are? There's only so many classes of hardware, so there's only so many groups. About 8 in total. You add the user to all of them at once. It worked just fine before polkit arrived.
Why would you want to temporarily grant privileges to hardware once? Who is trying to prevent the user from using their own hardware?
What's the very good reason all desktops use it?
>Who is trying to prevent the user from using their own hardware?
I don't understand this question. The functionality here is equivalent to sudo, you type your password to authenticate a certain action. As the sysadmin you can configure some actions to always accept or always deny, if you want.
You can do this with sudo too.
It'd be a problem if more than one user in logged in to the local console, in a multi head environment for example. But those are rare, and already have to solve the same problem for other console related devices such as mice and keyboard.
FSVO "all". Mine doesn't use it. If I have a task that needs elevated privileges, I run it from a terminal. Seems to work for me.
Just to follow this discussion a bit further: If you have a task that /really/ needs elevated privileges you could turn it into a kernel module. That's great for you if you want to do that, but will you tell everyone else to develop kernel modules for every little thing? I don't think I would. I'm happy to give the muggles a better interface.
There's a bunch of influential people that are bent on making "Linux desktop" be something that competes effectively with Windows and MacOS. Setting aside that I don't think those are particularly desirable objectives in the first place, I simply don't see it happening. Despite their deficiencies, Windows and MacOS work better than Linux desktops.
A lot of the Linux desktop effort seems to really be "Linux laptop" - Linux support for machines that are constantly moving from one hotspot to another, and constantly having storage and other devices plugged in and unplugged. That isn't my use-case. Most of my Linux machines are servers with no GUI. The one with a GUI doesn't travel, and gets something plugged into it maybe once a month.
I realise that my usage pattern isn't universal; I was just correcting the claim that "all desktops use it". You only need one counterexample to refute such a claim.
And not necessarily with the interests of Windows or MacOS end users, but more corporate interests.
I think a lot of Windows users for example were and would still be fine with a system that is effectively a single-user desktop. A permission prompt to prevent random apps from spying on you using your microphone and camera is probably a Good Idea for the average user but all this user policy business is just pointless; users themselves should always have access to their own devices anyway, just as they would on old Windows installs where the user was typically the only user and always administrator.
And yeah, I don't like that a few people get to define what exactly constitutes a desktop for everyone. Especially if under the guise of "this is what a modern desktop requires" they're free to turn the platform into a bloated, overcomplicated mess.. exactly the kind of thing I was happy to get away from when I left proprietary operating systems behind two decades ago.
From what I have seen, the amount of users that want to go back to the Windows 95 style of security are an even fewer people. You can find distros that still ship a desktop from that era but they don't seem to be for much beyond novelty.
Please don't speak for everyone. It's exactly this patronizing we-know-better-than-you attitude that makes users hate their corporate software vendors.
> From what I have seen, the amount of users that want to go back to the Windows 95 style of security are an even fewer people.
I knew someone would immediately reply with this straw man as soon as they saw mention of old Windows. I said user policies are pointless for a single-user desktop. It's irrelevant whether dave and samantha can access the audio device in john's session because dave and samantha don't exist on john's personal computer and he sure ain't running an ssh daemon for them.
I'm not speaking of corporations here, this is basically every current desktop environment that is shipping on Linux right now. They are all either using polkit or they use something very similar to it because the idea of it (user asks to perform an action, show a prompt) is very straightforward and pretty much universal for GUIs by now. Some of them may be business-oriented but some aren't. If this doesn't fit the definition of "everyone" using desktop Linux then who else are you considering? And just to clarify, I would say using sudo with a fine-grained config is roughly equivalent to polkit, although less convenient for GUI users because it doesn't have pluggable authentication agents.
>I knew someone would immediately reply with this straw man as soon as they saw mention of old Windows. I said user policies are pointless for a single-user desktop.
This itself is a strawman though. Polkit and sudo and such are not strictly about user policies although you can use them for that.
Why would I want permission prompts? Most systems are single-user systems; if you're logged in, you're the administrator, even if you haven't yet invoked your superpowers. Arguambly you should have to confirm if you want to do something dodgy; but if all you have to do is say "Yes, thanks for the warning", then you don't need any kits.
Really, I have difficulty imagining this group of Linux users who are constantly hot-laptoping, so that they need multi-user support sprinkled all over the OS. I can see that it's useful in a pair-programming environment, where you might have a lab or workstations with a standard config; but apart from that, how often does someone else log in to a desktop/laptop computer you normally use? Or one you own?
I don't think hotdesking and hotplugging are urgent consumer requirements. I don't think the people producing this stuff are aiming it at consumers.
> or write something very similar to it
Or use what was written before, if it matches your use-case. That worked, for many people. Still does for some.
This is why polkit actions are the way they are, so you actually have a chance of being able to encode those one-off tasks into permissions for a GUI. It's not implemented for everything that requires root, and it probably won't ever be implemented for all of it but it's a lot better than it used to be. Part of it is improving because desktops like KDE made it easier to plug in new panels to the system settings, another part is that applications started using the higher level D-Bus APIs (like udisks2, timedated, networkmanager, etc) instead of trying to access the raw devices themselves.
>There's a bunch of influential people that are bent on making "Linux desktop" be something that competes effectively with Windows and MacOS. Setting aside that I don't think those are particularly desirable objectives in the first place, I simply don't see it happening. Despite their deficiencies, Windows and MacOS work better than Linux desktops.
I don't disagree with the last part here but, companies like Canonical exist and they get paid to ship this stuff. There are customers out there who want this, and they may very well be the ones paying some money or contributing maintenance towards keeping your browser and media player working on Linux. I don't know any overarching reason why these customers would deploy Linux instead of Windows, you would have to ask them.
>I realise that my usage pattern isn't universal; I was just correcting the claim that "all desktops use it". You only need one counterexample to refute such a claim.
Sorry but I don't think any usage of the terminal is a counterexample. That's just sidestepping the desktop, you could also do that from a VT with no GUI present.
Not the applications that I use! The machine in question doesn't have dbus or systemd. It only has one user. That layer of complexity is of zero value to me, but it's the very devil to get rid of it all.
> Sorry but I don't think any usage of the terminal is a counterexample.
If, on Windows, you have to perform a task for which there is no pre-made GUI app you can install, then you have to run-up powershell or cmd. My case is identical. I specifically referred to one-off tasks.
It's not my use of terminals that is the counterexample; it's the fact that I run a desktop without polkit (or anything-kit).
Yes you can technically build a system without dbus or systemd or polkit or gettext or the C library or whatever it is you feel is superfluous. As you've found it is not actually difficult to do that, just tedious and impractical. You aren't gaining anything here by removing things. If you want equivalent functionality you're now tasked with building the equivalents, e.g. Android which is also a single user userspace for Linux without dbus or systemd, but has its own fairly complex set of high level services and IPC system.
That is the opposite of what I have found; I find that it's "the very devil" to remove these components. And my finding is that the presence of these components is tedious and impractical, and that their absence makes my life better.
> You aren't gaining anything here by removing things.
That is condescending.
I've used machines with these services and I've used machines without. I find it's a gain to not have them. Who are you to tell me whether I do or don't gain anything?
FTR I don't have to build anything; there are alternatives, which I use. Unfortunately these new components are more-or-less rivetted-in, which makes it hard to remove them and replace them. Screws are better than rivets.
I am sure that somewhere having an actual programming language available vs list of what can and can't be run with or without a password would enable some additional power in terms of control of the system but I cannot for the life of me imagine a situation where it would be all that useful.
$ getfacl -p /dev/snd/pcmC0D0c
# file: /dev/snd/pcmC0D0c
# owner: root
# group: audio
user::rw-
user:sam:rw-
group::rw-
mask::rw-
other::---
(I don't know if the scheme is able to revoke access to a running process, but it's still a step up from a single, static 'audio' group).
It irritates me that the Linux environment is constantly growing more complex to account for scenarios that are not relevant for me, and it's hard to opt out. That complexity is not zero-cost; I've been hit by many a bug (and have wasted a lot of time working around..) related to things that exist on my system yet serve no real purpose for me.
I guess it's the year of the Linux desktop when it gets corporate enough, and those who want a comfortable free operating system will be looking for alternatives :)
And there's no SSH exploit necessary. I'm not talking about a hacker from the internet, I'm talking about a malicious co-worker.
The old permission model of "just add everyone to the audio group" is not sufficient.
Sounds great! What could possibly go wrong?
The C library is something that I actually need, unlike a GUI sudo prompt for.. audio? I don't even know what such a prompt looks like because I've never seen one.
> If these libraries shipped with your distro, you asked for them.
If a bomb ships with a package you ordered, you asked for it.
Or maybe not? Maybe I didn't ask for it but a bunch of devs decided that (quoting you) "the users all want" it and I wasn't there to keep tabs on them.
And now that I know better, yes, I am looking for alternative distros because the ones I've been using include too many things I didn't ask for.
Sure, security also was not great for decades. I know what you mean you don't have time to vet packages, very few people have time to do that, that's usually why you'd trust a vendor to do it for you and not keep second guessing their decisions because they published and fixed a CVE.
>I am looking for alternative distros because the ones I've been using include too many things I didn't ask for.
That's great, I wish you luck. Just keep in mind, eventually if you find you want to put a security prompt on something for whatever reason (maybe you find yourself shipping something to a less technically inclined user), I expect you will circle back around to the same solutions. They're there for you to use them. At that point it becomes whether the frustration with XML and Javascript is worth rewriting it with a different configuration format and scripting language. Maybe you also want to take these tools written in C and rewrite it in Go or Rust or something, I don't know. I would not say it's worth it unless you have some really extreme requirements. This doesn't to have the most expressive DSL you can think of it, it just needs to encode some simple logic in a well-understood way.
Yes, I'm inevitably putting some trust in vendors. Unfortunately I'm having a hard time finding vendors (especially Linux vendors) that I can trust to make decisions that I find sensible and more or less in line with my intended usage of the system.
I have some experience with OpenBSD (after using it for more than a decade on a server and a few years on a laptop), and I can say with reasonable confidence that they would have never allowed polkit to be a part of their system in the first place. Similar to how they eventually said no to kerberos and just purged it. Similar to how they've refused things like PAM. Similar to how audio kept working fine with sndio (a very simple library & daemon) while I constantly had to battle the overcomplicated audio subsystem and ever-churning daemons on Linux..
That's the kind of Linux vendor I would like: a vendor who's trying to build something simple, and not something that tries to be maximally flexible and "everything for everyone". A vendor who can make decisions and if needed, build their own thing that suits their goals instead of shipping the same things every other distro ships.
There certainly are hundreds of distros as you say, but most of them offer little more than a different coat of paint, and ship the same third-party packages with more or less the same dependencies as you would have on any other Linux distro. After you've installed the few things you need, it doesn't matter much whether the banner says Arch, Fedora, Ubuntu, or whatever (in fact I run all three right now).
> That's great, I wish you luck.
Thank you.
Or maybe you asked your computer to do something as basic as give a web page access to your webcam, microphone and a screen capture of your desktop.