fix control socket listener (didn't chdir /)

[rafork]

When a control socket is in use, the process inherits and retains the existing current working directory. This is a problem when it happens to be in the file system of a removeable storage device like a USB stick. Later, when the user tries to umount the removeable storage, it fails because an ssh process is still using it as a current working directory. The ssh process has to be identified and terminated before the removeable storage can be umounted. This patch changes daemon(1, 1) in the control_persist_detach() function to daemon(0, 1) so that daemon() will chdir /.

[djmdjm]

the problem here is that the user may have specified cwd-relative files for particular things that are needed later (e.g. Unix domain socket forwardings) and these will break if the directory changes

[rafork]

On Thu, Sep 02, 2021 at 10:11:18PM -0700, Damien Miller ***@***.***> wrote: the problem here is that the user may have specified cwd-relative files for particular things that are needed later (e.g. Unix domain socket forwardings) and these will break if the directory changes

And it's a problem if they haven't done so. I'm surprised that anyone would specify cwd relative files. I could understand $HOME relative files, but not cwd relative files. Shows what I know. :-) What's the best default? Assuming that cwd relative files are used, or assuming that they haven't been used? Perhaps the correct solution is to change the directory to / for the control socket listener, and transform all cwd relative file references into absolute file references. That way, both use cases work. cheers, raf