Route::filter('auth', function() { if (Auth::guest()) return Redirect::guest('login'); });
Route::post('user', array('before' => 'csrf', function() { // process user data }));This code defines a route for handling user input, with a per-route filter named "csrf" that checks for Cross-Site Request Forgery (CSRF) attacks before processing the data. The PHP package/library that provides this functionality is typically a routing framework, such as Laravel, Lumen, or Symfony. These frameworks provide routing features, such as defining routes and filters, as well as other associated functionality (e.g. controllers, views, middleware).