The ServiceAccessController class does not work with ip6 addresses. I have added an if statement that skips ip6 addresses.
Also I think we should use the standard ip bit mask filtering rule style for the masks that xinetd uses. I found a ok description of the style here http://www.hn.edu.cn/book/NetWork/NetworkingBookshelf_2ndEd/tcp/ch12_05.htm (look near the bottom of this page) but I bet there are better ones out there.
172.16.12.5 defines a specific host
184.108.40.206 defines all hosts with an address that begins with 129.6
0.0.0.0 matches all addresses
defines four different hosts: 172.16.12.3, 172.16.12.6, 172.16.12.8, and 172.16.12.23
172.16.12.128/25 match every address from 172.16.12.128 to 172.16.12.255
I also think you can do the following which is an address and a mask: