As I can see, at the moment the file upload.php contains several serious and security related issues.

• Completely inappropriate way of uploading files to Moodle (to the dirroot)
• No access control
• No validation / sanitization of the user input (e.g. $_REQUEST["name"] containing paths with ../../../.. etc allowing to traverse.

This is unacceptable way of uploading files to Moodle. Let me suggest to stick with the standard forms and repository APIs for things like this.