maintenance_exempt.module in Maintenance Exempt 8

Allow exemption from maintenance mode.

File

maintenance_exempt.module

<?php

/**
 * @file
 * Allow exemption from maintenance mode.
 */
use Drupal\Core\Url;
use Drupal\Core\Link;

/**
 * Implements hook_form_FORM_ID_alter().
 */
function maintenance_exempt_form_system_site_maintenance_mode_alter(&$form, &$form_state) {
  $config = \Drupal::config('maintenance_exempt.settings');
  $query_key = $config
    ->get('query_key');
  $client_ip = \Drupal::request()
    ->getClientIp();
  $form['maintenance_exempt_by_ip'] = [
    '#type' => 'fieldset',
    '#title' => t('Set Exemption by IP'),
    '#weight' => 1,
    '#collapsible' => TRUE,
  ];
  $form['maintenance_exempt_by_ip']['exempt_ips'] = [
    '#type' => 'textarea',
    '#title' => t('Exempt IPs'),
    '#default_value' => $config
      ->get('exempt_ips'),
    '#description' => t('Enter a newline-separated list of IP addresses who should be exempt from maintenance mode. <a href="@cidr_link">CIDR Notation</a> is allowed.', [
      '@cidr_link' => 'http://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing',
    ]),
    '#suffix' => t('Your current IP address is %current', [
      '%current' => $client_ip,
    ]),
  ];
  $form['maintenance_exempt_by_url'] = [
    '#type' => 'fieldset',
    '#title' => t('Set Exemption by URL'),
    '#weight' => 1,
    '#collapsible' => TRUE,
  ];
  $form['maintenance_exempt_by_url']['exempt_urls'] = [
    '#type' => 'textarea',
    '#title' => t('Exempt URLs'),
    '#default_value' => $config
      ->get('exempt_urls'),
    '#description' => t('Enter a newline-separated list of paths which should be exempt from maintenance mode.'),
  ];
  $form['maintenance_exempt_by_query_string'] = [
    '#type' => 'fieldset',
    '#title' => t('Set Exemption by query string'),
    '#weight' => 2,
    '#collapsible' => TRUE,
    '#collapsed' => $query_key,
  ];
  $form['maintenance_exempt_by_query_string']['query_key'] = [
    '#type' => 'textfield',
    '#title' => t('Exempt query string'),
    '#default_value' => $query_key,
    '#description' => t('Enter a string which can be used as a variable in the <a href="@query_string">query string</a> to exempt a visitor from maintenance mode.', [
      '@query_string' => 'http://en.wikipedia.org/wiki/Query_string',
    ]),
  ];
  if ($query_key) {
    $current_exemption_link = Url::fromRoute('<front>', [], [
      'query' => [
        $query_key => '',
      ],
    ]);
    $form['maintenance_exempt_by_query_string']['query_key']['#suffix'] = Link::fromTextAndUrl('Hyperlink to exempt a visitor', $current_exemption_link)
      ->toString();
  }
  $form['#submit'][] = 'maintenance_exempt_form_system_site_maintenance_mode_submit';
}

/**
 * Helper function to process submit callback.
 */
function maintenance_exempt_form_system_site_maintenance_mode_submit(&$form, $form_state) {
  $config_factory = \Drupal::configFactory();
  $config = $config_factory
    ->getEditable('maintenance_exempt.settings');
  $config
    ->set('exempt_ips', $form_state
    ->getValue('exempt_ips'))
    ->set('exempt_urls', $form_state
    ->getValue('exempt_urls'))
    ->set('query_key', $form_state
    ->getValue('query_key'))
    ->save();
}

/**
 * Get list of exempt IP addresses from settings.
 *
 * @return array
 *   URLs that should be exempt from maintenance mode.
 */
function maintenance_exempt_get_ips() {
  $config = \Drupal::config('maintenance_exempt.settings');
  $allowed_ips = $config
    ->get('exempt_ips');
  return array_map('trim', explode("\n", $allowed_ips));
}

/**
 * Get list of exempt URLs from settings.
 *
 * @return array
 *   URLs that should be exempt from maintenance mode.
 */
function maintenance_exempt_get_urls() {
  $config = \Drupal::config('maintenance_exempt.settings');
  $allowed_urls = $config
    ->get('exempt_urls');
  return array_map('trim', explode("\n", $allowed_urls));
}

/**
 * Check if an IP address using CIDR notation should be exempt.
 *
 * @param string $ip
 *   The IP address.
 *
 * @return bool
 *   TRUE if the address should
 */
function maintenance_exempt_by_cidr_notation($ip) {
  $allowed_ips = maintenance_exempt_get_ips();
  foreach ($allowed_ips as $entry) {
    if (strstr($entry, "/")) {
      if (maintenance_exempt_ip_cidr_check($ip, $entry)) {
        return TRUE;
      }
    }
  }
  return FALSE;
}

/**
 * Helper function to check against CIDR.
 *
 * Thanks claudiu - http://www.php.net/manual/en/ref.network.php#74656
 *
 * @param string $ip
 *   The IP address to check.
 * @param string $cidr
 *   The netmask in CIDR notation.
 *
 * @return bool
 *   TRUE if the IP address matches.
 */
function maintenance_exempt_ip_cidr_check($ip, $cidr) {
  [
    $net,
    $mask,
  ] = explode("/", $cidr);
  $ip_net = ip2long($net);
  $ip_mask = ~((1 << 32 - $mask) - 1);
  $ip_ip = ip2long($ip);
  $ip_ip_net = $ip_ip & $ip_mask;
  return $ip_ip_net == $ip_net;
}

Functions

Name	Description
maintenance_exempt_by_cidr_notation	Check if an IP address using CIDR notation should be exempt.
maintenance_exempt_form_system_site_maintenance_mode_alter	Implements hook_form_FORM_ID_alter().
maintenance_exempt_form_system_site_maintenance_mode_submit	Helper function to process submit callback.
maintenance_exempt_get_ips	Get list of exempt IP addresses from settings.
maintenance_exempt_get_urls	Get list of exempt URLs from settings.
maintenance_exempt_ip_cidr_check	Helper function to check against CIDR.