function remote_client_authorized() {
   // ...
   $client_addr = get_client_addr();
   // ...
   $client_name = gethostbyaddr($client_addr);
   // ...
   $pollers = db_fetch_assoc('SELECT * FROM poller', true, $poller_db_cnn_id);
   foreach($pollers as $poller) {
      if (remote_agent_strip_domain($poller['hostname']) == $client_name) {
         return true;
      // ...

<?php
// ...
function get_client_addr($client_addr = false) {
   $http_addr_headers = array(
       // ...
       'HTTP_X_FORWARDED',
       'HTTP_X_FORWARDED_FOR',
       'HTTP_X_CLUSTER_CLIENT_IP',
       'HTTP_FORWARDED_FOR',
       'HTTP_FORWARDED',
       'HTTP_CLIENT_IP',
       'REMOTE_ADDR',
   );

   $client_addr = false;
   foreach ($http_addr_headers as $header) {
      // ...
      $header_ips = explode(',', $_SERVER[$header]);
      foreach ($header_ips as $header_ip) {
         // ...
         $client_addr = $header_ip;
         break 2;
      }
   }
   return $client_addr;
}

// ... retrieve poller items from database ...

foreach($items as $item) {
   switch ($item['action']) {
   // ...
   case POLLER_ACTION_SCRIPT_PHP: /* script (php script server) */
      // ...
      $cactiphp = proc_open(read_config_option('path_php_binary') . ' -q ' . $config['base_path'] . '/script_server.php realtime ' . $poller_id, $cactides, $pipes);