TCP Wrapper Support
Well you all must be aware of TCP Wrappers and the ease by which they can be used to control services.
But as you know that they have a limitation.
TCP-based applications have been compiled with wrappers support (usually using the libwrap library) and are wrapper aware.
Some common application that are used under wrappers for access control are telnet, ssh, sendmail, ftp packages, pop3, and stunnel.
To see if your application has wrapper support, you can either use the ldd command or strings command.
Here is a illustrated example of using ldd and strings to find whether the application supports wrapper or not.