Fix queries default EDNS behavior

[tgreenx]

Purpose

This PR proposes a fix which made queries to default as EDNS queries, which was unintended. Documentation has been updated to reflect the new behavior.

Context

Fixes zonemaster/zonemaster#1308

How to test this PR

Manual testing can be done using the commands below.

$ perl -MZonemaster::Engine -E 'my $ns = Zonemaster::Engine->ns("d.nic.fr", "194.0.9.1"); say $ns->query("afnic.fr", "A")->string';
;; ->>HEADER<<- opcode: QUERY, rcode: NOERROR, id: 35768
;; flags: qr ; QUERY: 1, ANSWER: 0, AUTHORITY: 4, ADDITIONAL: 2
;; QUESTION SECTION:
;; afnic.fr.    IN      A

;; ANSWER SECTION:

;; AUTHORITY SECTION:
afnic.fr.       3600    IN      NS      ns1.nic.fr.
afnic.fr.       3600    IN      NS      g.ext.nic.fr.
afnic.fr.       3600    IN      NS      ns3.nic.fr.
afnic.fr.       3600    IN      NS      ns2.nic.fr.

;; ADDITIONAL SECTION:
g.ext.nic.fr.   3600    IN      A       194.0.36.1
g.ext.nic.fr.   3600    IN      AAAA    2001:678:4c::1

;; Query time: 18 msec
;; SERVER: 194.0.9.1
;; WHEN: Tue Nov 19 19:27:39 2024
;; MSG SIZE  rcvd: 156

An optional hash can be passed as parameter to the query method, with keys such as dnssec and edns_size. They should be changed and/or removed to see the different behaviors. The EDNS line in the response should be inspected to see the outcome.

$ perl -MZonemaster::Engine -E 'my $ns = Zonemaster::Engine->ns("d.nic.fr", "194.0.9.1"); say $ns->query("afnic.fr", "A", { "dnssec" => 0, "edns_size" => 1024 })->string';
;; ->>HEADER<<- opcode: QUERY, rcode: NOERROR, id: 33671
;; flags: qr ; QUERY: 1, ANSWER: 0, AUTHORITY: 4, ADDITIONAL: 2
;; QUESTION SECTION:
;; afnic.fr.    IN      A

;; ANSWER SECTION:

;; AUTHORITY SECTION:
afnic.fr.       3600    IN      NS      ns3.nic.fr.
afnic.fr.       3600    IN      NS      g.ext.nic.fr.
afnic.fr.       3600    IN      NS      ns1.nic.fr.
afnic.fr.       3600    IN      NS      ns2.nic.fr.

;; ADDITIONAL SECTION:
g.ext.nic.fr.   3600    IN      A       194.0.36.1
g.ext.nic.fr.   3600    IN      AAAA    2001:678:4c::1

;; Query time: 17 msec
;; EDNS: version 0; flags: ; udp: 1232
;; SERVER: 194.0.9.1
;; WHEN: Tue Nov 19 19:28:46 2024
;; MSG SIZE  rcvd: 167

[matsduf]

The value must no be larger than 64 kB. If the value is smaller than 512 it must be treated as 512. Maybe we will create a test case where it is set smaller.

Is it possible by this code to create a non-DNSSEC EDNS query without specifying the size and get the default?