php判断来源网址地址并且限制非法来源

$fromHost = array(

'paipai.com',

'localhost',

'127.0.0.1'

);

$s = 'http://www.paipai.Com/chong/abc.shtml';

$urlArr = parse_url($s);

$host = isset($urlArr['host'])?$urlArr['host']:'';

$host = strtolower(str_ireplace('www.','',$host));

echo $host.'-->';

echo in_array($host,$fromHost)?'允许通过':'非法来源';

　　//$referer 为来源网址

$referer = $_SERVER['HTTP_REFERER'];