OpenSnitch is a GNU/Linux port of the Little Snitch firewall
...You can also convert temporary rules to permanent by right-clicking on a temporary rule or by double-clicking on it, and then edit it. By default OpenSnitch UI listens on a local Unix socket in /tmp/osui.sock.
inetid is a simple wrapper for services started from inetd.conf. It can give you ip-, host- and port-information about the socket that's created when your service gets spawned by inetd. you can use it with or without tcp_wrappers. available in perl & C.