title: Determining requester's IP address in RPC call
body: <p>In Go using the standard <code>net/rpc</code> functionality, I would like to determine what the IP address an inbound RPC request is coming from.  The underlying <code>http</code> functionality appears to provide this in the <code>http.Request</code> object, but I cannot see any way of getting at that from the default RPC handler (set using <code>rpc.HandleHTTP</code>).</p>
  
  <p>Is there some hidden mechanism for getting at the underlying <code>http.Request</code>, or do I have to do something fancier with setting up a different HTTP responder?</p>