api dns, add reverse lookup (also for https://github.com/opnsense/core/issues/1788 )

src/opnsense/mvc/app/controllers/OPNsense/Diagnostics/Api/DnsController.php

@@ -0,0 +1,61 @@
+<?php
+
+/**
+ *    Copyright (C) 2017 Deciso B.V.
+ *    All rights reserved.
+ *
+ *    Redistribution and use in source and binary forms, with or without
+ *    modification, are permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright notice,
+ *       this list of conditions and the following disclaimer.
+ *
+ *    2. Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *
+ *    THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ *    INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ *    AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ *    AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
+ *    OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ *    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ *    POSSIBILITY OF SUCH DAMAGE.
+ */
+
+namespace OPNsense\Diagnostics\Api;
+
+use \OPNsense\Base\ApiControllerBase;
+use \OPNsense\Core\Config;
+use \OPNsense\Core\Backend;
+
+/**
+ * Class DnsController
+ * @package OPNsense\Diagnostics
+ */
+class DnsController extends ApiControllerBase
+{
+
+    /**
+     * perform a reverse dns lookup
+     * @param string|array $address ip address or list of addresses
+     * @return array
+     */
+    public function reverse_lookupAction($address)
+    {
+        if ($this->request->isGet()) {
+            $this->sessionClose(); // long running action, close session
+            $address = !is_array($address) ? array($address) : $address;
+            $result = array();
+            foreach ($address as $addr) {
+                $result[] = gethostbyaddr($addr);
+            }
+            return $result;
+        } else {
+            return null;
+        }
+    }
+}