PHP - определяем пользователя, который сидит через PROXY

Бывает, что нужно отсеивать пользователей от некоторого функционала сайта, которые заходят на него через PROXY сервера. Есть несколько методов решения этого вопроса. Можно настроить сам сервер для этого функционала, а можно воспользоваться самим PHP для этого.

<?php
// Script php : Detection Proxy

@set_time_limit(0);
@error_reporting(E_ALL | E_NOTICE);
 
function get_ip() {
  if($_SERVER) {
    if($_SERVER['HTTP_X_FORWARDED_FOR'])
      $ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
    elseif($_SERVER['HTTP_CLIENT_IP'])
      $ip = $_SERVER['HTTP_CLIENT_IP'];
    else
      $ip = $_SERVER['REMOTE_ADDR'];
  }
  else {
    if(getenv('HTTP_X_FORWARDED_FOR'))
      $ip = getenv('HTTP_X_FORWARDED_FOR');
    elseif(getenv('HTTP_CLIENT_IP'))
      $ip = getenv('HTTP_CLIENT_IP');
    else
      $ip = getenv('REMOTE_ADDR');
  }
 
  return $ip;
}
 
function detect_proxy($myIP) {
   $scan_headers = array(
			'HTTP_VIA',
			'HTTP_X_FORWARDED_FOR',
			'HTTP_FORWARDED_FOR',
			'HTTP_X_FORWARDED',
			'HTTP_FORWARDED',
			'HTTP_CLIENT_IP',
			'HTTP_FORWARDED_FOR_IP',
			'VIA',
			'X_FORWARDED_FOR',
			'FORWARDED_FOR',
			'X_FORWARDED',
			'FORWARDED',
			'CLIENT_IP',
			'FORWARDED_FOR_IP',
			'HTTP_PROXY_CONNECTION'
		);
 
   $flagProxy = false;
   $libProxy = 'No';
 
   foreach($scan_headers as $i)
			if($_SERVER[$i]) $flagProxy = true;
 
   if (    in_array($_SERVER['REMOTE_PORT'], array(8080,80,6588,8000,3128,553,554))
        || @fsockopen($_SERVER['REMOTE_ADDR'], 80, $errno, $errstr, 30))
      $flagProxy = true;
 
   // Proxy LookUp
   if ( $flagProxy == true &&
        isset($_SERVER['REMOTE_ADDR']) && 
        !empty($_SERVER['REMOTE_ADDR']) )
         // Transparent Proxy
         // REMOTE_ADDR = proxy IP
         // HTTP_X_FORWARDED_FOR = your IP   
         if ( isset($_SERVER['HTTP_X_FORWARDED_FOR']) && 
              !empty($_SERVER['HTTP_X_FORWARDED_FOR']) &&
              $_SERVER['HTTP_X_FORWARDED_FOR'] == $myIP
            ) 
             $libProxy = 'Transparent Proxy';
               // Simple Anonymous Proxy            
              // REMOTE_ADDR = proxy IP
              // HTTP_X_FORWARDED_FOR = proxy IP
         else if ( isset($_SERVER['HTTP_X_FORWARDED_FOR']) && 
                   !empty($_SERVER['HTTP_X_FORWARDED_FOR']) &&
                   $_SERVER['HTTP_X_FORWARDED_FOR'] == $_SERVER['REMOTE_ADDR']
                 )
                 $libProxy = 'Simple Anonymous (Transparent) Proxy';
              // Distorting Anonymous Proxy            
              // REMOTE_ADDR = proxy IP
              // HTTP_X_FORWARDED_FOR = random IP address
              else if ( isset($_SERVER['HTTP_X_FORWARDED_FOR']) && 
                        !empty($_SERVER['HTTP_X_FORWARDED_FOR']) &&
                        $_SERVER['HTTP_X_FORWARDED_FOR'] != $_SERVER['REMOTE_ADDR']
                      )
                      $libProxy = 'Distorting Anonymous (Transparent) Proxy';
                   // Anonymous Proxy
                   // HTTP_X_FORWARDED_FOR = not determined
                   // HTTP_CLIENT_IP = not determined
                   // HTTP_VIA = determined
                   else if ( $_SERVER['HTTP_X_FORWARDED_FOR'] == '' &&
                             $_SERVER['HTTP_CLIENT_IP'] == '' &&
                             !empty($_SERVER['HTTP_VIA'])
                           )
                           $libProxy = 'Anonymous Proxy';
                        // High Anonymous Proxy            
                        // REMOTE_ADDR = proxy IP
                        // HTTP_X_FORWARDED_FOR = not determined                    
                        else
                           $libProxy = 'High Anonymous Proxy';
 
   return $libProxy;
}
 
$ip = get_ip();
 
echo 'Proxy Server Detection<br>';
echo '=================<br><br>';
$typeProxy = detect_proxy($ip);
echo 'Use Proxy Server : '.$typeProxy.'<br>';
echo '<br>';
echo 'Brief IP Information'.'<br>';
echo '--------------------'.'<br>'; 
echo 'Your IP : '.$ip.'<br>';
echo 'Language : '.$_SERVER['HTTP_ACCEPT_LANGUAGE'].'<br>';
echo '<br>';
echo 'Detail IP Information'.'<br>';
echo '---------------------'.'<br>'; 
echo 'HTTP_ACCEPT : '.$_SERVER['HTTP_ACCEPT'].'<br>';
echo 'HTTP_ACCEPT_ENCODING : '.$_SERVER['HTTP_ACCEPT_ENCODING'].'<br>';
echo 'HTTP_ACCEPT_LANGUAGE : '.$_SERVER['HTTP_ACCEPT_LANGUAGE'].'<br>';
echo 'HTTP_ACCEPT_CHARSET : '.$_SERVER['HTTP_ACCEPT_CHARSET'].'<br>';
echo 'HTTP_CONNECTION : '.$_SERVER['HTTP_CONNECTION'].'<br>';
echo 'HTTP_HOST : '.$_SERVER['HTTP_HOST'].'<br>';
echo 'HTTP_KEEP_ALIVE : '.$_SERVER['HTTP_KEEP_ALIVE'].'<br>';
echo 'HTTP_USER_AGENT : '.$_SERVER['HTTP_USER_AGENT'].'<br>';
echo 'REMOTE_HOST : '.@gethostbyaddr($_SERVER['REMOTE_ADDR']).'<br>';
echo 'REMOTE_PORT : '.$_SERVER['REMOTE_PORT'].'<br>';
echo '<br>';
echo 'REMOTE_ADDR : '.$_SERVER['REMOTE_ADDR'].'<br>';
echo 'HTTP_VIA : '.$_SERVER['HTTP_VIA'].'<br>';
echo 'HTTP_X_FORWARDED_FOR : '.$_SERVER['HTTP_X_FORWARDED_FOR'].'<br>';
echo 'HTTP_PROXY_CONNECTION : '.$_SERVER['HTTP_PROXY_CONNECTION'].'<br>';
echo 'HTTP_CLIENT_IP : '.$_SERVER['HTTP_CLIENT_IP'].'<br>';
?>