How to disable proxy access in php

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($_SERVER[&#39;HTTP_VIA&#39;]) and empty($_SERVER[&#39;HTTP_X_FORWARDED_FOR&#39;]) and empty($_SERVER[&#39;HTTP_XROXY_CONNECTION&#39;]) and empty($_SERVER[&#39;HTTP_PRAGMA&#39;]) ){
// 没有使用代理
}else{
exit(&#39;<meta charset="utf-8" />禁止使用代理访问&#39;);
}