Out-of-chroot pidfile handling?

[hhartzer]

Is it possible to handle PID files out of a chroot? This may be beyond darkhttpd in general, but it'd be kind of a cool thing to support.

We could hold an open file descriptor on the PID file before chroot, but I'm not sure it's possible to unlink with just the file descriptor.

[emikulic]

You could open a file descriptor for the parent directory of the pidfile before chroot and then use unlinkat.

I'm not sure if this is a good idea security-wise. IIUC you can subvert a chroot by chdiring to the outside of it, i.e. using that open fd.

[hhartzer]

That's an interesting idea. I'll have to think on that.

[emikulic]

I think doing this might be a bit over the top. Is there other software that does this, and evaluated the security aspects of doing so?

[hhartzer]

It might be, for sure. Not as far as I know, but there could be some. More of a thought. I can close this out if you like.