File Source for audiopost.php

<?php
//file_put_contents("result.txt", print_r($_POST, true));
//file_put_contents("result3.txt", print_r($_FILES, true));
//file_put_contents("result2.txt", print_r($_GET, true));
require('../inc/global.inc.php');
// check the request comes from our red5 server
$ips = gethostbynamel(api_get_setting('service_visio','visio_host'));
$is_our_server = false;
// ignoring null file
if ($_FILES["file"]["size"] == 0)
exit(0);
if(is_array($ips))
{
foreach($ips as $ip)
{
//get 255 range for known server address
$split = split('.',$ip);
$ip_range_server = $split[0].'.'.$split[1].'.'.$split[2];
//get 255 range for request source address
$split = split('.',$_SERVER['REMOTE_ADDR']);
$ip_range_request = $split[0].'.'.$split[1].'.'.$split[2];
if($ip_range_server == $ip_range_request){$is_our_server = true;}
}
}
if($is_our_server)
{
if(api_get_setting('service_visio','active')=='true')
{
//check encryption key
$string1 = $_GET['course_code'].$_GET['user_id'].gmdate('Ymd').$_configuration['security_key'];
$string2 = $_GET['course_code'].$_GET['user_id'].(gmdate('Ymd')-1).$_configuration['security_key'];
if(md5($string1) == $_GET['checker'] or md5($string2) == $_GET['checker'])
{
$course_info = api_get_course_info($_GET['course_code']);
$target = api_get_path(SYS_COURSE_PATH).$course_info['path'].'/document/audio/';
$basename = basename( $_FILES['file']['name']);
$target = $target . $basename ;
if(!move_uploaded_file($_FILES['file']['tmp_name'], $target))
{
error_log(__FILE__.':'.__LINE__.': File upload to '.$target.' failed',0);
}
else
{
require_once(api_get_path(LIBRARY_PATH).'fileUpload.lib.php');
$id = add_document($course_info,'/audio/'.$basename,'file',filesize($target),$basename);
if($id !== false)
{
$res = api_item_property_update($course_info,TOOL_DOCUMENT,$id,'DocumentAdded',$_GET['user_id']);
if($res === false)
{
error_log(__FILE__.':'.__LINE__.': Something went wrong with item properties update of '.$target,0);
}
else
{//make sound invisible?
//$res = api_item_property_update($course_info,TOOL_DOCUMENT,$id,'invisible',$_GET['user_id']);
}
}
else
{
error_log(__FILE__.':'.__LINE__.': Could not create document record for document '.$target,0);
}
}
}
else
{
error_log(__FILE__.':'.__LINE__.': Attempting to save file but hash check did not suceed (hacking attempt?)',0);
}
}
else
{
error_log(__FILE__.':'.__LINE__.': Attempting to save file but videoconf is not enabled',0);
}
}
else
{
error_log(__FILE__.':'.__LINE__.': Attempting to save file but coming from unknown source',0);
}
?>

Source for file audiopost.php