Updates NAMESERVER15

[matsduf]

Purpose

The objective of the test case states about name servers that "it may sometimes be desirable not to reveal that information" but then if it does, this test case only sends an INFO message. An INFO message does not signal that there is any reason to look at it. This PR raises the level to NOTICE.

$ zonemaster-cli --test nameserver/nameserver15 telia.com --raw
   0.00 INFO     UNSPECIFIED    GLOBAL_VERSION   version=v4.7.2
   1.57 INFO     NAMESERVER15   N15_SOFTWARE_VERSION   ns_ip_list=dns358.fi.telia.net/88.194.40.67;dns49.de.telia.net/2001:2030:c000:5::4;dns49.de.telia.net/213.248.77.82; query_name=version.bind; string=9.18.9
   1.58 INFO     NAMESERVER15   N15_SOFTWARE_VERSION   ns_ip_list=dns1.telia.com/2001:2040:c001:101::5;dns1.telia.com/81.228.11.67;dns2.telia.com/2001:2040:c001:401::6;dns2.telia.com/81.228.10.67; query_name=version.bind; string=9.18.11

The specification does not distinguish between a server that does not respond at all on a "version query" and a server that responds, but with no version information. In the following example some of the servers do not respond at all and some of them responds with no information. This PR splits the message and make the test case make a distinction.

$ zonemaster-cli --test nameserver/nameserver15 festo.press --raw
   0.00 INFO     UNSPECIFIED    GLOBAL_VERSION   version=v4.7.2
  41.67 INFO     NAMESERVER15   N15_NO_VERSION   ns_ip_list=ns2.atvirtual.com/185.136.96.210;ns2.atvirtual.com/2a06:fb00:1::1:210;ns6.atvirtual.com/185.136.97.210;ns6.atvirtual.com/2a06:fb00:1::2:210;ns7.atvirtual.com/185.136.98.210;ns7.atvirtual.com/2a06:fb00:1::3:210;ns8.atvirtual.com/185.136.99.210;ns8.atvirtual.com/2a06:fb00:1::4:210

This PR also make the test case skip servers that do not even answer SOA queries to make it lift up any servers that do not answer because it is a "version query".

This PR also changes the argument from ns_ip_list to ns_list to give more information. It uses the same technique introduced by #1179.

This PR also updates the test case to check the class in the response.

Context

Also see zonemaster/zonemaster-engine#1281

Also see #1208

Also see test zones that match this update in #1217.

Changes

The specification of NAMESERVER15.

How to test this PR

Review the proposed changes.

[matsduf]

@tgreenx, you wrote the specification. Please review this proposal of updates.

[matsduf]

@tgreenx and @marc-vanderwal, please re-review.

[matsduf]

@marc-vanderwal, are you also fine with this?

[marc-vanderwal]

Yes, that looks good to me!

[matsduf]

Test zone specification for this test case in #1217

[matsduf]

@tgreenx and @marc-vanderwal, I made a version string just consisting of space to be equal to empty version string.

[matsduf]

Test zone specification for this test case in #1217

Now the test zones have been implemented.

[matsduf]

@tgreenx, you did the current implementation of Nameserver15. Could you do the update?

[tgreenx]

@tgreenx, you did the current implementation of Nameserver15. Could you do the update?

Yes

[matsduf]

A trivial merge conflict was resolved after two approvals. Merge without waiting for renewed approval.