判断ip是否为内网ip

gistfile1.php

<?php

function is_intranet_ip($ip = null) {
    if (!$ip) {
        $ip = $_SERVER['REMOTE_ADDR'];
    }
    $long_ip = ip2long($ip);
    $ret = false;
    // 分别判断10. 192.168.  172.16-31. 127.0.0.1
    if ($long_ip >> 24 == 0xa || $long_ip >> 20 == 0xac1 || $long_ip >> 16 == 0xc0a8 || $long_ip == 0x7f000001) {
        $ret = true;
    }
    return $ret;
}