Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/modules/ban/src/BanMiddleware.php

@@ -0,0 +1,58 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\ban\BanMiddleware.
+ */
+
+namespace Drupal\ban;
+
+use Drupal\Component\Utility\SafeMarkup;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
+
+/**
+ * Provides a HTTP middleware to implement IP based banning.
+ */
+class BanMiddleware implements HttpKernelInterface {
+
+  /**
+   * The decorated kernel.
+   *
+   * @var \Symfony\Component\HttpKernel\HttpKernelInterface
+   */
+  protected $httpKernel;
+
+  /**
+   * The ban IP manager.
+   *
+   * @var \Drupal\ban\BanIpManagerInterface
+   */
+  protected $banIpManager;
+
+  /**
+   * Constructs a BanMiddleware object.
+   *
+   * @param \Symfony\Component\HttpKernel\HttpKernelInterface $http_kernel
+   *   The decorated kernel.
+   * @param \Drupal\ban\BanIpManagerInterface $manager
+   *   The ban IP manager.
+   */
+  public function __construct(HttpKernelInterface $http_kernel, BanIpManagerInterface $manager) {
+    $this->httpKernel = $http_kernel;
+    $this->banIpManager = $manager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function handle(Request $request, $type = self::MASTER_REQUEST, $catch = TRUE) {
+    $ip = $request->getClientIp();
+    if ($this->banIpManager->isBanned($ip)) {
+      return new Response(SafeMarkup::format('Sorry @ip has been banned', ['@ip' => $ip]), 403);
+    }
+    return $this->httpKernel->handle($request, $type, $catch);
+  }
+
+}