[getdns-api] EDNS options are for server to server communications

[Andrew Sullivan]

On Thu, Feb 13, 2014 at 03:54:29PM +0100, Willem Toorop wrote:
> EDNS0 options are for server to server communications.

I don't know where you get that idea.  Saith RFC 6891:

   EDNS is a hop-by-hop extension to DNS.  This means the use of EDNS is
   negotiated between each pair of hosts in a DNS resolution process,
   for instance, the stub resolver communicating with the recursive
   resolver or the recursive resolver communicating with an
   authoritative server.

There is nothing about EDNS0 options that makes them reserved to
"servers", and indeed thinking about the DNS in terms of a
client-server model is probably a mistake.  The protocol is
fundamentally peer to peer.  The _actors_ are generally either
requesters or responders (sometimes, the same actor is doing both
actions, but it's only acting in one role at a time).

> How about a GETDNS_RETURN_EDNS0_WITH_RECURSIVE_DISALLOWED return code?

I don't think I understand what this is supposed to do.  Are you
saying you want the EDNS0 options where RA=0, or where RD=1 but RA=0,
or where RD=0?

Best regards,

A

-- 
Andrew Sullivan
Dyn, Inc.
asullivan at dyn.com
v: +1 603 663 0448