(firewall) add new Util class containing often used (static) helpers.

(cherry picked from commit 3e47ec94)

plist

@@ -388,6 +388,7 @@
 /usr/local/opnsense/mvc/app/library/OPNsense/Core/Singleton.php
 /usr/local/opnsense/mvc/app/library/OPNsense/Firewall/FilterRule.php
 /usr/local/opnsense/mvc/app/library/OPNsense/Firewall/Plugin.php
+/usr/local/opnsense/mvc/app/library/OPNsense/Firewall/Util.php
 /usr/local/opnsense/mvc/app/models/OPNsense/Base/BaseModel.php
 /usr/local/opnsense/mvc/app/models/OPNsense/Base/BaseModelMigration.php
 /usr/local/opnsense/mvc/app/models/OPNsense/Base/Constraints/AllOrNoneConstraint.php

src/opnsense/mvc/app/library/OPNsense/Firewall/Util.php

+<?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\Firewall;
+
+use \OPNsense\Core\Config;
+
+/**
+ * Class Util, common static firewall support functions
+ * @package OPNsense\Firewall
+ */
+class Util
+{
+      /**
+       * is provided address an ip address.
+       * @param string $network address
+       * @return boolean
+       */
+      public static function isIpAddress($address)
+      {
+          return !empty(filter_var($address, FILTER_VALIDATE_IP));
+      }
+
+      /**
+       * is provided network valid
+       * @param string $network network
+       * @return boolean
+       */
+      public static function isSubnet($network)
+      {
+          $tmp = explode('/', $network);
+          if (count($tmp) == 2) {
+              if (self::isIpAddress($tmp[0]) && abs($tmp[1]) == $tmp[1]) {
+                  if (strpos($tmp[0], ':') !== false && $tmp[1] <= 128) {
+                      // subnet v6
+                      return true;
+                  } elseif ($tmp[1] <= 32) {
+                      // subnet v4
+                      return true;
+                  }
+              }
+          }
+          return false;
+      }
+
+      /**
+       * check if name exists in alias config section
+       * @param string $name name
+       * @return boolean
+       */
+      public static function isAlias($name)
+      {
+          if (!empty(Config::getInstance()->object()->aliases)) {
+              foreach (Config::getInstance()->object()->aliases->children() as $node) {
+                  if ($node->name == $name) {
+                      return true;
+                  }
+              }
+          }
+          return false;
+      }
+
+      /**
+       * check if name exists in alias config section
+       * @param string $number port number or range
+       * @param boolean $allow_range ranges allowed
+       * @return boolean
+       */
+      public function isPort($number, $allow_range=true)
+      {
+          $tmp = explode(':', $number);
+          foreach ($tmp as $port) {
+              if (!getservbyname($port, "tcp") && !getservbyname($port, "udp")
+                  && filter_var($port, FILTER_VALIDATE_INT, array(
+                      "options" => array("min_range"=>1, "max_range"=>65535))) === false
+              ) {
+                  return false;
+              }
+          }
+          if (($allow_range && count($tmp) <=2) || count($tmp) == 1) {
+              return true;
+          }
+          return false;
+      }
+}