PHP 限制访问-支持多ip-通配符-IP段

/**
 * HOST访问限制 支持 IP(单IP,多IP,*通配符,IP段) 域名(单域名,多域名,*通配符)
 * 根据判断实现IP地址 白名单黑名单
 * Author：70(qq781787584)
 * @param unknown $host 当前host 127.0.0.2
 * @param unknown $list 允许的host列表 127.0.0.*,192.168.1.1,192.168.1.70,127.1.1.33-127.1.1.100
 * @return boolean
 */
function in_host($host, $list) {
    $list = ',' . $list . ',';
    $is_in = false;
    // 1.判断最简单的情况
    $is_in = strpos ( $list, ',' . $host . ',' ) === false ? false : true;
    // 2.判断通配符情况
    if (! $is_in && strpos ( $list, '*' ) !== false) {
        $hosts = array ();
        $hosts = explode ( '.', $host );
        // 组装每个 * 通配符的情况
        foreach ( $hosts as $k1 => $v1 ) {
            $host_now = '';
            foreach ( $hosts as $k2 => $v2 ) {
                $host_now .= ($k2 == $k1 ? '*' : $v2) . '.';
            }
            // 组装好后进行判断
            if (strpos ( $list, ',' . substr ( $host_now, 0, - 1 ) . ',' ) !== false) {
                $is_in = true;
                break;
            }
        }
    }
    // 3.判断IP段限制
    if (! $is_in && strpos ( $list, '-' ) !== false) {
        $lists = explode ( ',', trim ( $list, ',' ) );
        $host_long = ip2long ( $host );
        foreach ( $lists as $k => $v ) {
            if (strpos ( $v, '-' ) !== false) {
                list ( $host1, $host2 ) = explode ( '-', $v );
                if ($host_long >= ip2long ( $host1 ) && $host_long <= ip2long ( $host2 )) {
                    $is_in = true;
                    break;
                }
            }
        }
    }
    return $is_in;
}