Apache2::Request UPLOAD_HOOK and mod_perl Handler

hi,

 I've got a few questions about the UPLOAD_HOOK of Apache2::Request
 and the way implementing it. I'm not sure, whether this is the right
 mailinglist or not, so sorry if this is not the right one. ;-)

 I'm trying to write a Perl Class which provides a handler() function
 for mod_perl. something like that:

     package InterRed::UploadLimiter;

     use strict;
     use Digest::MD5 qw(md5_hex);
     use CGI::Cookie;
 
     sub handler
     {
         my $r = shift;
         my $transparent_hook = sub {
         my ($upload, $data, $data_len, $hook_data) = @_;
            warn "$hook_data: got $data_len bytes for " . $upload->name;
         };

         my $req = Apache2::Request->new($r,
            UPLOAD_HOOK => $transparent_hook,
         );
         $req->parse();
        
         return Apache2::Const::OK;
     }
     
     1;
     __END__

 My main goal is to register this handler in the apache and so to
 control user uploads. I want to check the uploaded filesize and
 abort the upload if it's to huge. Then I want to redirect to another
 script (with parameters) or print something out.

 Therefor I tried to register my handler like that in my apache config
 file:

        <IfModule mod_perl.c>
#               PerlFixupHandler        InterRed::UploadLimiter
#               PerlChildInitHandler    InterRed::UploadLimiter
                PerlHandler             InterRed::UploadLimiter
        </IfModule>

 As you can see, I tried different Handler types, because I'm not sure
 which one is right to handle uploads (the upload must not be started
 at this time). I want the handler to control any kind of perl cgi
 script, which sends uploads to the server.

 In case of the PerlHandler I got no error, but handler and hook are not
 fired anyway. Same using PerlChildInitHandler.
 In case of the PerlFixupHandler the client receives a 0 byte answer
 (even if their is no upload submitted). The callback $transparent_hook
 doesn't seem to be called. The handler is called in this case.

 So, what is the right Handler to register the upload hook?
 What am I doing wrong?
 Why does the client receive a 0 byte answer in case of using
 the PerlFixupHandler?
 
greetings,
Michael