织梦DedeCMS使用CDN加速后获取真实IP的方法

{dede:php}
$user_IP = ($_SERVER["HTTP_VIA"]) ? $_SERVER["HTTP_X_FORWARDED_FOR"] : $_SERVER["REMOTE_ADDR"];
$user_IP = ($user_IP) ? $user_IP : $_SERVER["REMOTE_ADDR"];
function get_real_ip(){
$ip=false;
if(!empty($_SERVER["HTTP_CLIENT_IP"])){
$ip = $_SERVER["HTTP_CLIENT_IP"];
}
if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
$ips = explode (", ", $_SERVER['HTTP_X_FORWARDED_FOR']);
if ($ip) { array_unshift($ips, $ip); $ip = FALSE; }
for ($i = 0; $i < count($ips); $i++) {
if(!preg_match("/^(10|172.16|192.168)./", $ $ips[$i])) {
$ip = $ips[$i];
break;
}
}
}
return ($ip ? $ip : $_SERVER['REMOTE_ADDR']);
}
echo " "." ". get_real_ip();
{/dede:php}