Peer credentials on Unix socket

[Kixunil]

tokio-rs/tokio-uds#13 was recently merged, so I'd like to open an issue of adding same thing to stdlib. TL;DR It allows one to get effective UID and GID of the process which created the remote socket.

I suggest to test it with Tokio now and when there is consensus, we can merge similar change. I need this function, so I'm going to test it anyway.

[Kixunil]

Considering that newtypes for pid_t, uid_t and gid_t landed in nix, we shoul consider using same newtypes in std and then simply reexport them in nix.

[sfackler]

This seems like a reasonable addition. It looks like there are some extra platforms that require special handling though - Solaris and FreeBSD: https://doxygen.postgresql.org/getpeereid_8c_source.html

[Kixunil]

The implementation in tokio handles Linux and FreeBSD (incl. macOS). I doesn't handle Solaris because I don't have Solaris machine.

[dtolnay]

This isn't my area of expertise but I would be interested to see an API proposed for this in a PR.

[joechrisellis]

Hi guys. We're quite keen for something like this in the stdlib. The implementation in the Tokio repository looks good to me, and from a cursory glance it looks like the stdlib can be very similar. I'm happy to give this a crack -- should I submit an RFC first or is a normal code pull request OK? 😄

Cheers! 🙂

[hug-dev]

The PR which implements this issue is ready for review 🚀
#75148

[Kixunil]

Since the PR was merged should the labels (and perhaps also the title) be updated to tracking issue?

[hug-dev]

I would agree with that!
I guess the steps to follow for stabilization are here?