Play has NOT any built-in solution for access control, the easiest thing you can do is just placing Play application behind some HTTP server in role of proxy and gate-keeper, which will filter it for you, ie. nginx or Apache.
On the other hand you can also intercept each request within Global object of Play which gives you even better flexibility, although you need to implement it yourself.
Edit: Here you have simple sample for matching IP with some pattern: http://www.java2s.com/Code/Java/Network-Protocol/CheckifIPaddressmatchpattern.htm