application that track ftpclient requests and runs in background of ftpserver

i want to track ftp user request when they made requests to upload file to some specific ftpserver and the user request that ftpuser has made to download a file from ftpserver. My problem is that how to track that file name and location which the client is uploading on the server and downloading from the server before the request is reached to server and i want to rename the file the user is uploading to the server if a file with same name exist at the same location.

Is there any api functions or any class liabraries in .net that we can use to solve this problem. if suppose some body has any solution please mail me on [email protected] as soon as possible.
please.

thanks.

The only way that I could think of is to hook into network socket stack (no idae on how to do it) which pretty much the same way how network sniffer works.