Basic03 (basic03)

Status: Final

Purpose

Detect the “broken but functional” case by probing A records for www.<child-zone> against delegation nameservers.
Provide a compatibility path when Basic02 failed but the domain can still answer basic web-style queries.

Preconditions And Inputs

Preconditions:
- A zone.Zone is provided.
- Delegation nameserver addresses can be loaded using Method4.
Required inputs:
- Child zone name (z.Name).
- Derived query name www.<child-zone>.
Profile/config knobs that affect behavior:
- net.ipv4: enables or disables IPv4 A probes.
- net.ipv6: enables or disables IPv6 A probes.
- resolver.defaults.parallel: controls per-test parallel nameserver probing.

Algorithm And Decision Flow

In module orchestration (basic.All):
- If Basic02 emitted B02_AUTH_RESPONSE_SOA, Basic03 function is skipped and HAS_NAMESERVER_NO_WWW_A_TEST is emitted.
- Otherwise Basic03 function runs.
Basic03 function emits TEST_CASE_START.
Build queryName = "www." + child-zone.
Resolve nameserver targets with Method4 and probe each in parallel:
- Emit transport enable/disable tags (IPV4_*, IPV6_*) for rrtype A.
- Send A query for queryName.
- If response has A RR for queryName, emit HAS_A_RECORDS; otherwise emit NO_A_RECORDS.
If no probed nameserver produced any response packet, emit A_QUERY_NO_RESPONSES.
Emit TEST_CASE_END.

Emitted Tags (Possible Set)

Tag	Emitted when
`A_QUERY_NO_RESPONSES`	No nameserver produced a response packet for `A` query to `www.<child-zone>`.
`HAS_A_RECORDS`	A nameserver responded with at least one `A` RR for `www.<child-zone>`.
`HAS_NAMESERVER_NO_WWW_A_TEST`	Module orchestration skipped `Basic03` because `Basic02` succeeded (`B02_AUTH_RESPONSE_SOA`).
`IPV4_DISABLED`	IPv4 transport is disabled for `A` probe.
`IPV4_ENABLED`	IPv4 transport is enabled for `A` probe.
`IPV6_DISABLED`	IPv6 transport is disabled for `A` probe.
`IPV6_ENABLED`	IPv6 transport is enabled for `A` probe.
`NO_A_RECORDS`	Nameserver responded but no `A` RR matched `www.<child-zone>`.
`TEST_CASE_END`	Testcase completion marker is emitted.
`TEST_CASE_START`	Testcase start marker is emitted.

Tag Arguments

Tag	Argument key	Type	Meaning
`A_QUERY_NO_RESPONSES`	`-`	`-`	No arguments.
`HAS_A_RECORDS`	`ns`	`string`	Nameserver identity (`ns` name only; use `address` for IP) that returned `A` records.
`HAS_A_RECORDS`	`address`	`string`	Nameserver IP address for the same endpoint.
`HAS_A_RECORDS`	`domain`	`string`	Queried name (`www.<child-zone>`).
`HAS_NAMESERVER_NO_WWW_A_TEST`	`zname`	`string`	Child zone name for skipped `Basic03` probing path.
`IPV4_DISABLED`	`ns`	`string`	Nameserver identity (`ns` name only; use `address` for IP).
`IPV4_DISABLED`	`address`	`string`	Nameserver IP address for the same endpoint.
`IPV4_DISABLED`	`rrtype`	`string`	rrtype skipped (`A`).
`IPV4_ENABLED`	`ns`	`string`	Nameserver identity (`ns` name only; use `address` for IP).
`IPV4_ENABLED`	`address`	`string`	Nameserver IP address for the same endpoint.
`IPV4_ENABLED`	`rrtype`	`string`	rrtype queried (`A`).
`IPV6_DISABLED`	`ns`	`string`	Nameserver identity (`ns` name only; use `address` for IP).
`IPV6_DISABLED`	`address`	`string`	Nameserver IP address for the same endpoint.
`IPV6_DISABLED`	`rrtype`	`string`	rrtype skipped (`A`).
`IPV6_ENABLED`	`ns`	`string`	Nameserver identity (`ns` name only; use `address` for IP).
`IPV6_ENABLED`	`address`	`string`	Nameserver IP address for the same endpoint.
`IPV6_ENABLED`	`rrtype`	`string`	rrtype queried (`A`).
`NO_A_RECORDS`	`ns`	`string`	Nameserver identity (`ns` name only; use `address` for IP) with no matching `A` data.
`NO_A_RECORDS`	`address`	`string`	Nameserver IP address for the same endpoint.
`NO_A_RECORDS`	`domain`	`string`	Queried name (`www.<child-zone>`).
`TEST_CASE_END`	`testcase`	`string`	Testcase display name (`Basic03`).
`TEST_CASE_START`	`testcase`	`string`	Testcase display name (`Basic03`).

Severity Levels Per Tag

Tag	Level	Notes
`A_QUERY_NO_RESPONSES`	`INFO`	Default from `share/profile.json`.
`HAS_A_RECORDS`	`ERROR`	Default from `share/profile.json`.
`HAS_NAMESERVER_NO_WWW_A_TEST`	`INFO`	Default from `share/profile.json`.
`IPV4_DISABLED`	`DEBUG`	Default from `share/profile.json`.
`IPV4_ENABLED`	`DEBUG`	Default from `share/profile.json`.
`IPV6_DISABLED`	`DEBUG`	Default from `share/profile.json`.
`IPV6_ENABLED`	`DEBUG`	Default from `share/profile.json`.
`NO_A_RECORDS`	`DEBUG`	Default from `share/profile.json`.
`TEST_CASE_END`	`DEBUG`	Default from `share/profile.json`.
`TEST_CASE_START`	`DEBUG`	Default from `share/profile.json`.

Differences From Upstream

Upstream reference: basic03.md
Differences (Upstream vs Gonemaster):
- Upstream: does not define a skip marker for this path. Gonemaster: emits HAS_NAMESERVER_NO_WWW_A_TEST when Basic03 is skipped because Basic02 succeeded.
- Upstream: outcome text says testcase fails when no response contains an A record. Gonemaster: default levels make HAS_A_RECORDS the error path and keep NO_A_RECORDS at DEBUG.
Potential upstream report:
- yes
If yes, include:
- Upstream expected behavior: Basic03 outcome text describes failure when no A evidence is found.
- Gonemaster observed behavior: severity contract treats HAS_A_RECORDS as the strong signal (ERROR) and NO_A_RECORDS as non-failing (DEBUG default).
- evidence: engine/test/basic/basic.go (All, Basic03), share/profile.json (test_levels.BASIC).
- report status: not filed

Edge Cases And Limitations

If Method4 yields no nameserver addresses, function path emits only testcase markers unless orchestration emitted HAS_NAMESERVER_NO_WWW_A_TEST.
A_QUERY_NO_RESPONSES is emitted only when there are zero response packets; responses without A produce NO_A_RECORDS instead.
Per-nameserver output ordering is deterministic after parallel execution due runner merge order.