introduce $allowedIpConfiguration

Ip configuration that determines if an administrator can log in.
Defaults to null which means that no ip check is being performed.

Module.php

@@ -84,6 +84,22 @@ class Module extends BaseModule
     /** @var array Model map */
     public $modelMap = [];
 
+    /** @var array Ip configuration that determines if an administrator can log in.
+     * Defaults to null which means that no ip check is being performed.
+     * It uses the yii\validators\IpValidator for validation:
+     * @see http://www.yiiframework.com/doc-2.0/guide-tutorial-core-validators.html#ip
+     * @see http://www.yiiframework.com/doc-2.0/yii-validators-ipvalidator.html
+     * @example
+        'ranges' => [
+            '192.168.10.128'
+            '!192.168.10.0/24',
+            'any' // allows any other IP addresses
+            ]
+     * In this example, access is allowed for all the IPv4 and IPv6 addresses excluding the 192.168.10.0/24 subnet.
+     * IPv4 address 192.168.10.128 is also allowed, because it is listed before the restriction.
+     */
+    public $allowedIpConfiguration = null;
+
     /**
      * @var string The prefix for user module URL.
      *

models/LoginForm.php

@@ -14,10 +14,12 @@
 use dektrium\user\Finder;
 use dektrium\user\helpers\Password;
 use dektrium\user\traits\ModuleTrait;
+use yii\base\DynamicModel;
 use yii\helpers\ArrayHelper;
 use yii\helpers\Html;
 use Yii;
 use yii\base\Model;
+use yii\validators\IpValidator;
 
 /**
  * LoginForm get user's login and password, validates them and logs the user in. If user has been blocked, it adds
@@ -53,7 +55,7 @@ public function __construct(Finder $finder, $config = [])
         $this->finder = $finder;
         parent::__construct($config);
     }
-    
+
     /**
      * Gets all users to generate the dropdown list when in debug mode.
      *
@@ -145,6 +147,30 @@ public function login()
     }
 
 
+    /**
+     * Validates if an administrator is coming from the correct IP adress.
+     *
+     * @see Module $allowedIpConfiguration
+     * @see http://www.yiiframework.com/doc-2.0/guide-tutorial-core-validators.html#ip
+     * @see http://www.yiiframework.com/doc-2.0/yii-validators-ipvalidator.html
+     * @return mixed true if the check is correct, an array with the errors otherwise
+     */
+    public function checkValidIpAddresses()
+    {
+        $config = $this->module->allowedIpConfiguration;
+
+        if (!$this->user->isAdmin || !$config) {
+            return true;
+        }
+
+        $rules = ArrayHelper::merge(['login', 'ip'], $config);
+
+        $model = DynamicModel::validateData(['login' => Yii::$app->request->userIP], [$rules]);
+
+        return $model->hasErrors() ? $model->getErrors() : true;
+    }
+
+
     /** @inheritdoc */
     public function formName()
     {
@@ -157,6 +183,14 @@ public function beforeValidate()
         if (parent::beforeValidate()) {
             $this->user = $this->finder->findUserByUsernameOrEmail(trim($this->login));
 
+            $valid = $this->checkValidIpAddresses();
+
+            if($valid !== true) {
+                foreach($valid as $error) {
+                    $this->addError('login', $error);
+                }
+            }
+
             return true;
         } else {
             return false;