php如何禁止代理访问

if($_SERVER['HTTP_PROXY_CONNECTION'] || $_SERVER['HTTP_VIA'] || $_SERVER['HTTP_USER_AGENT_VIA'] || $_SERVER['HTTP_X_FORWARDED_FOR'] || $_SERVER['HTTP_PROXY_CONNECTION'] || $_SERVER['HTTP_CACHE_CONTROL'] || $_SERVER['HTTP_CACHE_INFO']) {
 die("请勿使用代理服务器访问, 谢谢");
}

<?php
if(empty($_SERVER['HTTP_VIA']) and empty($_SERVER['HTTP_X_FORWARDED_FOR']) and empty($_SERVER['HTTP_XROXY_CONNECTION']) and empty($_SERVER['HTTP_PRAGMA']) ){
// 没有使用代理
}else{
exit('<meta charset="utf-8" />禁止使用代理访问');
}