Added support to Moodle v3.3+

settings.php

@@ -0,0 +1,40 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+/**
+ * @author Daniel Tomé <danieltomefer@gmail.com>
+ * @copyright 2017 Servei de Recursos Educatius (http://www.sre.urv.cat)
+ */
+
+defined('MOODLE_INTERNAL') || die;
+
+if ($ADMIN->fulltree) {
+    $settings->add(
+        new admin_setting_heading(
+            'auth_ip/auth_ipdescription',
+            '',
+            new lang_string('auth_ipdescription', 'auth_ip')
+        )
+    );
+
+    $settings->add(
+        new admin_setting_configtextarea(
+            'auth_ip/valid_ips',
+            new lang_string('auth_ipvalidips', 'auth_ip'),
+            new lang_string('auth_ipexampleips', 'auth_ip'),
+            ''
+        )
+    );
+}