Comment 7 for bug 1880240

Thanks Tim for the extra details.

A quick summary:

- There's no systemd xinetd generator to create .socket and .service files involved

- The uucp package provides both a .socket and .service file for uucp with defaults that match the xinetd configuration.

- Indeed, the systemd unit file doesn't describe all the available options that *could* be set. This is intentional. Focal's systemd understands roughly 245 such options, eg:

$ systemctl show ssh | wc -l
245

Listing all of the available options would drastically hurt the legibility of the systemd unit files.

If you wish to change the interfaces it listens on, you can use systemctl edit uucp.socket to change the [Socket] ListenStream setting. I don't see any systemd setting that corresponds to only_from -- but you can use ufw or iptables to restrict access to specific ranges.

Thanks