Getting the model inside a controller emberjs

I need to get the grand total price of all the objects returned from a JSON API.

my idea is to create a controller and set a property on it. Then grab the model loop over each object and add to the predefined property that objects total price. Something like this:

export default Ember.Controller.extend({
    orderTotal: 0,

    getOrderTotal: function(){
        var model = this.get('model');

        model.forEach(function(c){
            var order_total = this.get('orderTotal') * c.total_price;
            this.set('orderTotal', order_total)
        });
    }
});

problem is I can't get the model. How can I access the model inside a controller?