Why does Mozilla Extension cause requests to a URL to appear hitting multip

[Chandra Prakash]

I develop a PHP code and count how much data was downloaded by the client. My code is working fine if someone directly requests my file from a browser. But if someone installs a Mozilla extensions like ‘’downthemall’’ and then the url is requested by that extension then it requests the file URL 4 times so I get the downloaded data 4 times. How do I fix this? The same happened when the user is using jDownloader software or any software.

<?php

function getMimeType($fileName)
{
    $c_type_default = "application/octet-stream";
    $content_types = array(
        "exe" => "application/octet-stream",
        "zip" => "application/zip",
        "mp3" => "audio/mpeg",
        "mpg" => "video/mpeg",
        "avi" => "video/x-msvideo",
         "mp4" => "video/mp4",
    );
//  echo isset($content_types[pathinfo($fileName, PATHINFO_EXTENSION)]) ? $content_types[pathinfo($fileName, PATHINFO_EXTENSION)] : $c_type_default;     
    return isset($content_types[pathinfo($fileName, PATHINFO_EXTENSION)]) ? $content_types[pathinfo($fileName, PATHINFO_EXTENSION)] : $c_type_default;
}
function output_file($file, $name)
{

 /*
 This function takes a path to a file to output ($file),  the filename that the browser will see ($name) and  the MIME type of the file ($mime_type, optional).
 */

 //Check the file premission
 if(!is_readable($file)) die('File not found or inaccessible!');

 $size = filesize($file);

 $name = rawurldecode($name);

 //turn off output buffering to decrease cpu usage
     @ob_end_clean(); 
    include('../includes/configg.php');

    // Start Code  For Total Downloaded Data Size by The LoggedIn User
        $user="select * from $TBusers where id=".$_SESSION['log_id'];
        $result_user = mysqli_query($conn, $user) ;
        $row = mysqli_fetch_assoc($result_user);
        $lastsotrage = $row['down'];  
        $curr_date= $row['curr_date'];
        $today_date= date('d-m-y');
        $daily_downloaded_data= $row['daily_downloaded_data'];
        if($curr_date != $today_date)
        { 
              $update_curr_date="update $TBusers set curr_date ='$today_date', daily_downloaded_data =0 where id=".$_SESSION['log_id'];  // Set Curr_date by Today Date For check Daily Downloaded Data Limit

              mysqli_query($conn,$update_curr_date) ;
              $daily_downloaded_data=0;
        }
        /*else
        {
             if($daily_downloaded_data>=(20*1024*1024*1024)){           // Check Daily  Download Data Limit 20GB Exceed or not
             header('Location: http://idownload.club/members/download.php');
             exit;}
        }*/


 // required for IE, otherwise Content-Disposition may be ignored
 if(ini_get('zlib.output_compression'))
 ini_set('zlib.output_compression', 'Off');

 header('Content-Type: ' . getMimeType($name));
 header('Content-Disposition: attachment; filename="'.$name.'"');
 header("Content-Transfer-Encoding: binary");
 header('Accept-Ranges: bytes');

 /* The three lines below basically make the 
    download non-cacheable */
 header("Cache-control: private");
 header('Pragma: private');
 header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");

 // multipart-download and download resuming support
 if(isset($_SERVER['HTTP_RANGE']))
 {
    list($a, $range) = explode("=",$_SERVER['HTTP_RANGE'],2);
    list($range) = explode(",",$range,2);
    list($range, $range_end) = explode("-", $range);
    $range=intval($range);
    if(!$range_end) {
        $range_end=$size-1;
    } else {
        $range_end=intval($range_end);
    }

    $new_length = $range_end-$range+1;
    header("HTTP/1.1 206 Partial Content");
    header("Content-Length: $new_length");
    header("Content-Range: bytes $range-$range_end/$size");
 } else {
    $new_length=$size;
    header("Content-Length: ".$size);
 }

 /* Will output the file itself */
 $chunksize = 1*(1024*1024); //you may want to change this
 $bytes_send = 0;
 if ($file = fopen($file, 'r'))
 {
    if(isset($_SERVER['HTTP_RANGE']))
    fseek($file, $range);

    while(!feof($file) && 
        (!connection_aborted()) && 
        ($bytes_send<$new_length)
          )
    {
        $buffer = fread($file, $chunksize);
        print($buffer); //echo($buffer); // can also possible
        flush();
        $bytes_send += strlen($buffer);
    }
 fclose($file);

            $lastsotrage= $lastsotrage + $size;
            $daily_downloaded_data+=$size;
            $sql="update $TBusers set down =". $lastsotrage." where id=".$_SESSION['log_id'];
            $sql2="update $TBusers set daily_downloaded_data = $daily_downloaded_data where id=".$_SESSION['log_id'];
            $sql3= "update test set count=count+1 where id=1" ;
            mysqli_query($conn,$sql) ;
            mysqli_query($conn,$sql2) ;mysqli_query($conn,$sql3) ;
            file_put_contents('data.txt', print_r($_SERVER, true), FILE_APPEND);


 } else
 //If no permissiion
 die('Error - can not open file.');
 //die
die();
}
//Set the time out
set_time_limit(0);



//path to the file
$file_dir=$_GET['directory'];
$file_name = str_replace("/", "", $_GET['file']);
$file_name = str_replace("\\", "", $file_name);
$file = $file_dir . "/".$file_name; 


//Call the download function with file path,file name and file type
output_file($file, ''.$file_name.'');


?>

[Krispy Kritter]

Is there only a single file, or several versions of the file? DownThemAll scans a url for all files available on that page and allows the user to choose which file(s) get retrieved. Items such as images often show up twice (thumbnail and full size image). So it's likely related to how the objects are coded on the page.

[transporterfan]

Downloader managers also use multiple file access to download faster, so while they may look as though they are downloading 4 times, in reality they are reading only a part of each accessed file in 4 'splits' or segments. I have no idea what the solution is, but I have seen many cyberlockers forbidding their use.

[teodz1984]

Research
disable multi-thread downloads from the same IP