php $_SERVER
<?php
/*
Sometimes you will find that your website will not get the correct user IP after adding CDN, then this function will help you
*/
function real_ip()
{
$ip = $_SERVER['REMOTE_ADDR'];
if (isset($_SERVER['HTTP_X_FORWARDED_FOR']) && preg_match_all('#\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}#s', $_SERVER['HTTP_X_FORWARDED_FOR'], $matches)) {
foreach ($matches[0] AS $xip) {
if (!preg_match('#^(10|172\.16|192\.168)\.#', $xip)) {
$ip = $xip;
break;
}
}
} elseif (isset($_SERVER['HTTP_CLIENT_IP']) && preg_match('/^([0-9]{1,3}\.){3}[0-9]{1,3}$/', $_SERVER['HTTP_CLIENT_IP'])) {
$ip = $_SERVER['HTTP_CLIENT_IP'];
} elseif (isset($_SERVER['HTTP_CF_CONNECTING_IP']) && preg_match('/^([0-9]{1,3}\.){3}[0-9]{1,3}$/', $_SERVER['HTTP_CF_CONNECTING_IP'])) {
$ip = $_SERVER['HTTP_CF_CONNECTING_IP'];
} elseif (isset($_SERVER['HTTP_X_REAL_IP']) && preg_match('/^([0-9]{1,3}\.){3}[0-9]{1,3}$/', $_SERVER['HTTP_X_REAL_IP'])) {
$ip = $_SERVER['HTTP_X_REAL_IP'];
}
return $ip;
}
echo real_ip();
?>