The technologies I listed are not sandboxing, as that term refers to a different category of technology.
And you're right, kind of; you need to set the permissions for apps, but that doesn't mean they need cooperation from the software developers. The whole point is that they don't. With those technologies you can lock down complex closed source programs, something not possible with pledge.
Those seem to be of the category of “I have a program and I want to restrict what it does” which seems like a sandbox to me. The problem here is that trying to figure out what goes on this list is difficult for arbitrary programs, even when you’re the one writing it. When you’re just applying it to third party software it’s very likely something will not function correctly.
It's not a sandbox though, because it's a different type of technology. You can say it's a type of sandbox in concept, and you could make an argument, but referring to it as a sandbox in a technical discussion simply isn't correct.
> The problem here is that trying to figure out what goes on this list is difficult for arbitrary programs, even when you’re the one writing it. When you’re just applying it to third party software it’s very likely something will not function correctly.
That's why there are things like, for example, SELinux permissive mode, where you run the software as needed and observe the permissions it needs, and then grant it those permissions while denying everything else.
I mean the typical term used for such things is “mandatory access control” but they always get used to implement a sandbox so that’s what I call them.
Also, watching a program to see what it does is exactly the issue I’m talking about. You’re stuck with whatever behaviors you tested and everything else that you didn’t hit will fail (loudly if you’re lucky, silently if you’re not). There are platforms that do exactly what you’re talking about and believe me working on these rules is miserable. You’ll have reports on your desk like “the profiler doesn’t work anymore” (nobody tested this) or “on desktop controls don’t render anymore” (someone changed the implementation and it needs something you didn’t include in your rules). Again, this is when you control the stack, doing this for arbitrary programs is an order of magnitude harder.
What makes you think otherwise?