extended DNS errors support

Credit for the original prototype (!794 (closed)) goes to Stéphane Bortzmeyer and Vladimír Čunát. Supersedes !794 (closed).

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EDE codes

Used

• 0 - Other
• 3 - Stale Answer
• 4 - Forged Answer
• 6 - DNSSEC Bogus
• 7 - Signature Expired
• 8 - Signature Not Yet Valid
• 10 - RRSIGs Missing
• 12 - NSEC Missing
• 15 - Blocked
• 18 - Prohibited
• 20 - Not Authoritative
• 21 - Not Supported
• 22 - No Reachable Authority

Ununsed

• 1 - Unsupported DNSKEY Algorithm: we use Other(0) instead
• 2 - Unsupported DS Digest Type: we use Other(0) instead
• 5 - DNSSEC Indeterminate
• 9 - DNSKEY Missing: we use DNSSEC Bogus(6) instead
• 11 - No Zone Key Bit Set: we use DNSSEC Bogus(6) instead
• 13 - Cached Error
• 14 - Not Ready
• 16 - Censored: possible to use with DENY_MSG
• 17 - Filtered: possible to use with DENY_MSG
• 19 - Stale NXDOMAIN Answer: we use Stale Answer(3) instead
• 23 - Network Error
• 24 - Invalid Data

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TODOs

• figure out remaining TODOs in code
• do we want any test coverage? how?

changed milestone to %5.5.0

added feature label

mentioned in merge request !794 (closed)

added 16 commits

• 6dc8afd7 - lib/resolve: kr_extended_error_t and related func
• f23af8e7 - lib/log: add LOG_GRP_EDE
• 9e4d0e1a - modules/extended_error: OPT section modification
• de7928fa - validate: add extended DNS errors
• a8a8fdc0 - validate: refactor - remove check for impossible return values
• 43fdd775 - validate: additional EDE DNSSEC errors
• efe878ea - modules/extended_error: package module
• f0c2eeff - logging: remove QVERBOSE in favor of kr_log_q
• 80b9c267 - ede: add KNOT_EDNS_EDE_NREACH_AUTH
• 74d60983 - ede: handle stale answers
• 70eb1898 - ede: handle not authoritative
• eb7218ff - kluautil: kr_string2c function
• de70556d - lua: extended_error const table
• 2eecadff - modules/dns64: EDE - mark as forged
• 0c3d8ad5 - policy: add extended errors
• 4d6695bd - libknot: bump dependency version to 3.0.2

Compare with previous version

changed the description

added 1 commit

• e39dd1e1 - fixup! libknot: bump dependency version to 3.0.2

Compare with previous version

marked this merge request as draft from e39dd1e1

I wonder if each line that sets an EDE should put some code into the error message, allowing us to uniquely identify origin of the error. As the EDE codes themselves don't carry that much information, I suspect these could get very useful in debugging, and they could be rather cheap (a couple bytes).

added 1 commit

• b28e9f65 - fixup! validate: additional EDE DNSSEC errors

Compare with previous version

added 5 commits

• 52d97434 - fixup! modules/extended_error: OPT section modification
• 457ba1c6 - fixup! ede: add KNOT_EDNS_EDE_NREACH_AUTH
• 37a818c3 - fixup! validate: add extended DNS errors
• e7fce160 - fixup! lib/resolve: kr_extended_error_t and related func
• 528e6d4e - fixup! modules/dns64: EDE - mark as forged

Compare with previous version

mentioned in merge request !1239 (merged)