Mimic drupal rabbithole module

gistfile1.php

<?php 

function mymodule_node_view($node, $view_mode, $langcode) {
  // Mimic rabbit-hole module
  if (node_is_page($node)) {
     // Access denied:
     drupal_access_denied();
     drupal_exit();

     // Page not found:
     drupal_not_found();
     drupal_exit();

     // Redirect
     $url = '';
     drupal_goto($url);

  }
}