[dnstap] Adding support for DoT and DoH

[Chris Mikkelson]

On Tue, Dec 08, 2020 at 12:32:07AM -0500, Robert Edmonds wrote:
> It sounds like you're proposing to continue setting socket_protocol to
> TCP or UDP depending on the underlying IP protocol in use by a DoH/DoT
> connection?

Yes, precisely.

> I never really meant the SocketProtocol enums to mean the literal IP
> protocol numbers (otherwise I would have assigned TCP to be value 6 and
> UDP to be value 17). I like Vladimír's suggestion but I think it
> requires taking the "socket" and "transport" terms a little less
> literally.

Thank you for your analysis and particularly this background.

I will take this discussion as consensus for extending
SocketProtocol with DOH and DOT values (with those
names) and will put up something largely similar to
your text below:

    > // SocketProtocol: the protocol of the socket or connection used to
    > // transport a DNS message. This specifies how to interpret "transport
    > // port" fields or other fields occurring in "Message" payloads.
    > enum SocketProtocol {
    >     // RFC 1035 section 4.2.1 DNS over UDP transport.
    >     UDP = 1;
    > 
    >     // RFC 1035 section 4.2.2 DNS over TCP transport.
    >     TCP = 2;
    > 
    >     // RFC 7858 DNS over TLS.
    >     DOT = 3;
    > 
    >     // RFC 8484 DNS over HTTPS.
    >     DOH = 4;
    > }
    
for a final review shortly.

Thanks,
-- 
Chris Mikkelson
Farsight Security, Inc.
cmikk at fsi.io