How to read request content without eating it ?

[Ben RUBSON]

Hello,

I need to implement an access control handler based on request content.

So here is my (very simplified) PerlAccessHandler code :
sub handler {
  $r = shift;
  $r->read($content,$r->headers_in->{'Content-length'});
  if($content =~ /signature=expected_signature/)
  {
    return Apache2::Const::OK;
  }
  return Apache2::Const::AUTH_REQUIRED;
}

It works.
My problem is further, when handler returns OK and Apache runs the user 
requested CGI script.
The request content provides some additional parameters the target CGI script 
needs.
However, as soon as $r->read is used, request content is no more available to 
the CGI script.

So my question is, how to read request content without making it unavailable to 
the final requested CGI ?

Thank you very much,

Best regards,

Ben