ProxySubscriber.php in Stage File Proxy 8

Namespace

Drupal\stage_file_proxy\EventSubscriber

File

src/EventSubscriber/ProxySubscriber.php

<?php

namespace Drupal\stage_file_proxy\EventSubscriber;

use Drupal\Component\Utility\UrlHelper;
use Drupal\Core\Config\ConfigFactoryInterface;
use Drupal\Core\StreamWrapper\StreamWrapperManager;
use Drupal\Core\Url;
use Drupal\stage_file_proxy\EventDispatcher\AlterExcludedPathsEvent;
use Drupal\stage_file_proxy\FetchManagerInterface;
use Psr\Log\LoggerInterface;
use Symfony\Component\EventDispatcher\EventDispatcherInterface;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpFoundation\RequestStack;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\HttpKernel\KernelEvents;

/**
 * Stage file proxy subscriber for controller requests.
 */
class ProxySubscriber implements EventSubscriberInterface {

  /**
   * The manager used to fetch the file against.
   *
   * @var \Drupal\stage_file_proxy\FetchManagerInterface
   */
  protected $manager;

  /**
   * The logger.
   *
   * @var \Psr\Log\LoggerInterface
   */
  protected $logger;

  /**
   * The event dispatcher.
   *
   * @var \Symfony\Component\EventDispatcher\EventDispatcherInterface
   */
  protected $eventDispatcher;

  /**
   * The configuration factory.
   *
   * @var \Drupal\Core\Config\ConfigFactoryInterface
   */
  protected $configFactory;

  /**
   * The request stack.
   *
   * @var \Symfony\Component\HttpFoundation\RequestStack
   */
  protected $requestStack;

  /**
   * Construct the FetchManager.
   *
   * @param \Drupal\stage_file_proxy\FetchManagerInterface $manager
   *   The manager used to fetch the file against.
   * @param \Psr\Log\LoggerInterface $logger
   *   The logger interface.
   * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $event_dispatcher
   *   The event dispatcher.
   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
   *   The config factory.
   * @param \Symfony\Component\HttpFoundation\RequestStack $request_stack
   *   The request stack.
   */
  public function __construct(FetchManagerInterface $manager, LoggerInterface $logger, EventDispatcherInterface $event_dispatcher, ConfigFactoryInterface $config_factory, RequestStack $request_stack) {
    $this->manager = $manager;
    $this->logger = $logger;
    $this->eventDispatcher = $event_dispatcher;
    $this->configFactory = $config_factory;
    $this->requestStack = $request_stack;
  }

  /**
   * Fetch the file from it's origin.
   *
   * @param \Symfony\Component\HttpKernel\Event\GetResponseEvent $event
   *   The event to process.
   */
  public function checkFileOrigin(GetResponseEvent $event) {
    $config = $this->configFactory
      ->get('stage_file_proxy.settings');

    // Get the origin server.
    $server = $config
      ->get('origin');

    // Quit if no origin given.
    if (!$server) {
      return;
    }

    // Quit if we are the origin, ignore http(s).
    if (preg_replace('#^[a-z]*://#u', '', $server) === $event
      ->getRequest()
      ->getHost()) {
      return;
    }
    $file_dir = $this->manager
      ->filePublicPath();
    $request_path = $event
      ->getRequest()
      ->getPathInfo();
    $request_path = mb_substr($request_path, 1);
    if (strpos($request_path, '' . $file_dir) !== 0) {
      return;
    }

    // Disallow directory traversal.
    if (in_array('..', explode('/', $request_path))) {
      return;
    }

    // Moving to parent directory is insane here, so prevent that.
    if (in_array('..', explode('/', $request_path))) {
      return;
    }
    $alter_excluded_paths_event = new AlterExcludedPathsEvent([]);
    $this->eventDispatcher
      ->dispatch('stage_file_proxy.alter_excluded_paths', $alter_excluded_paths_event);
    $excluded_paths = $alter_excluded_paths_event
      ->getExcludedPaths();
    foreach ($excluded_paths as $excluded_path) {
      if (strpos($request_path, $excluded_path) !== FALSE) {
        return;
      }
    }

    // Note if the origin server files location is different. This
    // must be the exact path for the remote site's public file
    // system path, and defaults to the local public file system path.
    $remote_file_dir = trim($config
      ->get('origin_dir'));
    if (!$remote_file_dir) {
      $remote_file_dir = $file_dir;
    }
    $request_path = rawurldecode($request_path);

    // Path relative to file directory. Used for hotlinking.
    $relative_path = mb_substr($request_path, mb_strlen($file_dir) + 1);

    // If file is fetched and use_imagecache_root is set, original is used.
    $paths = [
      $relative_path,
    ];

    // Webp support.
    $is_webp = FALSE;
    if (strpos($relative_path, '.webp')) {
      $paths[] = str_replace('.webp', '', $relative_path);
      $is_webp = TRUE;
    }
    foreach ($paths as $relative_path) {
      $fetch_path = $relative_path;

      // Is this imagecache? Request the root file and let imagecache resize.
      // We check this first so locally added files have precedence.
      $original_path = $this->manager
        ->styleOriginalPath($relative_path, TRUE);
      if ($original_path && !$is_webp) {
        if (file_exists($original_path)) {

          // Imagecache can generate it without our help.
          return;
        }
        if ($config
          ->get('use_imagecache_root')) {

          // Config says: Fetch the original.
          $fetch_path = StreamWrapperManager::getTarget($original_path);
        }
      }
      $query = $this->requestStack
        ->getCurrentRequest()->query
        ->all();
      $query_parameters = UrlHelper::filterQueryParameters($query);
      $options = [
        'verify' => $config
          ->get('verify'),
      ];
      if ($config
        ->get('hotlink')) {
        $location = Url::fromUri("{$server}/{$remote_file_dir}/{$relative_path}", [
          'query' => $query_parameters,
          'absolute' => TRUE,
        ])
          ->toString();
      }
      elseif ($this->manager
        ->fetch($server, $remote_file_dir, $fetch_path, $options)) {

        // Refresh this request & let the web server work out mime type, etc.
        $location = Url::fromUri('base://' . $request_path, [
          'query' => $query_parameters,
          'absolute' => TRUE,
        ])
          ->toString();

        // Avoid redirection caching in upstream proxies.
        header("Cache-Control: must-revalidate, no-cache, post-check=0, pre-check=0, private");
      }
      if (isset($location)) {
        header("Location: {$location}");
        exit;
      }
    }
  }

  /**
   * Registers the methods in this class that should be listeners.
   *
   * @return array
   *   An array of event listener definitions.
   */
  public static function getSubscribedEvents() {

    // Priority 240 is after ban middleware but before page cache.
    $events[KernelEvents::REQUEST][] = [
      'checkFileOrigin',
      240,
    ];
    return $events;
  }

}

Classes

Name	Description
ProxySubscriber	Stage file proxy subscriber for controller requests.