Send Cross Origin request from iframe

Basically, I’ve build an app where users can generate an unique page. This can be included in their own page with an iframe. Now I want to know exactly which domain this is hosted on.

Using a meteor call inside the iframe.rendered function triggers a security error and rightfully so. What is the best way to send the web page details to my server?

Template.iframe.rendered = function() {
  var link = top.location.href;
  //Only show if it is linked from by other domain
  if (!link.indexOf("iframe/example")) {
  	var routeId = FlowRouter.getParam("routeId");'addIframeView', routeId, link);