How to find fanpage name/id from tab app

I have a FB app embedded on a a fanpage tab. When my app is called I can get the information in the signed request. But I need some more information so I can store and access data locally indexed by the particular fanpage and app.

How can I determine the name and id of开发者_如何转开发 the fanpage tab the app is embedded on (as opposed to the fanpage id which is in the signed_request)?

I know the app id is in the parent url but I don't think I can access the parent url from the child iframe for security reasons.

Like the page then go here and click on the 'likes' like about 1/3 of the way down. That will show you your likes, which will contain that page and its id