A php anti-hotlink code

/**
* @author seraphim
* @copyright 2013
* url: http:bbs.it-home.org
*/
$ADMIN = array(
'defaulturl'=> 'http://www.xx.com/images/banner-header.gif', //盗链返回的地址
'url_1' => 'http://www.xx.net/file',
'url_2' => 'http://www.xx.net/file1',
);
$okaysites = array(
'http://box.baidu.com',
'http://tieba.baidu.com/p/1493336008', //白名单
'http://www.xx.com/1.html',
);
$reffer = $_SERVER['HTTP_REFERER'];
if ($reffer) {
$yes = 0;
while (list($domain, $subarray) = each($okaysites)) {
if (ereg($subarray, "$reffer")) {
$yes = 1;
}
}
$theu = 'url_' . $_GET['site'];
$file = $_GET['file'];
if ($ADMIN[$theu] and $yes == 1) {
header("Location: $ADMIN[$theu]/$file");
} else {
header("Location: $ADMIN[defaulturl]");
}
} else {
header("Location: $ADMIN[defaulturl]");
}
print_r($_SERVER['HTTP_REFERER']);
/*
 url: http://bbs.it-home.org
*/
?>