Call method on an Ember controller from a global function

I have a global function

function onCCSuccess(data) {
    // call method on Ember controller and send data
}

That function needs to access a method on a controller inside my Ember app. I can't find out how to do that. When I look at the controller in the browser dev tools I don't see any of my declared properties or methods for the controller.

onCCSuccess gets called from an iFrame page. The iFrame sends data to onCCSuccess and I need to pass that data along to my Ember app. I could just recreate the methods outside the Ember app but that wouldn't be very DRY.