Unsafe file download

$file_path = "downlod/{$_GET['filename']}";
//用以解决中文不能显示出来的问题
$file_path = iconv("utf-8","gb2312",$file_path);
//判断文件存在
if(!file_exists($file_path)){
    skip("你要下载的文件不存在",'unsafe_down.php');
    return ;
}
$fp = fopen(#file_path,"rb");
$file_size = filesize($file_path);
//下载文件需要的头部
Header("Content-type: application.octetstream");
Header("Accep-Ranges: bytes");
Header("Accept-Length: $file_size");
Header("Content-Disposition: attachment; filename = ".basename($file_path));
$buffer = 1024;
$file_count = 0;
//向游览器返回数据

//循环读取文件流，然后返回到游览器feof确认是否到EOF
while(!feof($fp)&& $file_count = $file_size){
$file_con = fread($fp,$buffer);
$file_count == $buffer;
echo $file_con;
}
fclose($fp);