Basic01 (basic01)

Status: Final

Purpose

Determine whether the child zone exists and whether a parent zone can be identified from iterative authoritative responses.
Detect inconsistent delegation or alias outcomes while traversing from the root toward the child zone.

Preconditions And Inputs

Preconditions:
- A zone.Zone is provided with a non-empty name.
- A recursor is available on the zone object.
Required inputs:
- Child zone name (z.Name).
- Root server set from Recursor.RootServers().
Profile/config knobs that affect behavior:
- net.ipv4: enables or disables IPv4 queries.
- net.ipv6: enables or disables IPv6 queries.
- Undelegated mode via fake addresses (Recursor.HasFakeAddresses(child)).

Algorithm And Decision Flow

Emit TEST_CASE_START.
If child is root (.), emit B01_CHILD_FOUND and B01_ROOT_HAS_NO_PARENT, then emit TEST_CASE_END and return.
If child has fake addresses (undelegated context), emit B01_CHILD_FOUND and B01_PARENT_DISREGARDED, then emit TEST_CASE_END and return.
Start from root servers and iteratively probe with SOA/NS (and DNAME when needed), extending the intermediate name toward the child.
For each probed nameserver address:
- Emit transport enable/disable tags (IPV4_*, IPV6_*) per rrtype (SOA, NS, DNAME) and skip queries on disabled transports.
- Emit B01_SERVER_ZONE_ERROR when response requirements fail.
Collect parent/delegation observations and emit:
- B01_PARENT_FOUND for discovered parents.
- B01_PARENT_UNDETERMINED when multiple parent candidates exist.
- B01_PARENT_NOT_FOUND when none exists.
Emit child/delegation status:
- B01_CHILD_FOUND when delegation or authoritative SOA evidence exists.
- B01_INCONSISTENT_DELEGATION for inconsistent parent-side results.
- B01_NO_CHILD (normal mode) or B01_CHILD_NOT_EXIST (fake-address mode) when child evidence is absent.
Emit alias findings:
- B01_CHILD_IS_ALIAS per detected DNAME target.
- B01_INCONSISTENT_ALIAS when multiple alias targets are found.
Emit TEST_CASE_END.

Emitted Tags (Possible Set)

Tag	Emitted when
`B01_CHILD_NOT_EXIST`	No delegation/SOA evidence exists and child is in fake-address mode.
`B01_CHILD_IS_ALIAS`	Child is identified as alias via DNAME evidence.
`B01_CHILD_FOUND`	Child existence is confirmed (root, undelegated, delegation, or authoritative SOA path).
`B01_INCONSISTENT_ALIAS`	More than one DNAME target was observed for child aliasing.
`B01_INCONSISTENT_DELEGATION`	Parent-side responses for child delegation are inconsistent.
`B01_NO_CHILD`	No delegation/SOA evidence exists in normal mode (non-fake-address).
`B01_PARENT_DISREGARDED`	Fake-address (undelegated) mode is active, so parent search is skipped.
`B01_PARENT_FOUND`	At least one parent zone candidate is identified.
`B01_PARENT_NOT_FOUND`	No parent zone candidate was identified from any probed nameserver response.
`B01_PARENT_UNDETERMINED`	Multiple parent zone candidates were identified.
`B01_ROOT_HAS_NO_PARENT`	Child zone is root (`.`).
`B01_SERVER_ZONE_ERROR`	SOA/NS response validation fails for a probed server/query name.
`IPV4_DISABLED`	IPv4 transport is disabled for queried rrtype.
`IPV4_ENABLED`	IPv4 transport is enabled for queried rrtype.
`IPV6_DISABLED`	IPv6 transport is disabled for queried rrtype.
`IPV6_ENABLED`	IPv6 transport is enabled for queried rrtype.
`LOOP_PROTECTION`	Internal traversal loop protection threshold is hit.
`TEST_CASE_END`	Testcase completion marker is emitted.
`TEST_CASE_START`	Testcase start marker is emitted.

Tag Arguments

Tag	Argument key	Type	Meaning
`B01_CHILD_NOT_EXIST`	`domain`	`string`	Child zone name.
`B01_CHILD_IS_ALIAS`	`domain_child`	`string`	Child zone name.
`B01_CHILD_IS_ALIAS`	`domain_target`	`string`	Alias target name from DNAME.
`B01_CHILD_IS_ALIAS`	`servers`	`array<object>`	Structured nameserver list that returned the result.
`B01_CHILD_FOUND`	`domain`	`string`	Child zone name found.
`B01_INCONSISTENT_ALIAS`	`domain`	`string`	Child zone name with inconsistent alias targets.
`B01_INCONSISTENT_DELEGATION`	`domain_parent`	`string`	Parent zone candidate showing inconsistency.
`B01_INCONSISTENT_DELEGATION`	`domain_child`	`string`	Child zone name.
`B01_INCONSISTENT_DELEGATION`	`servers`	`array<object>`	Structured nameserver list tied to inconsistency.
`B01_NO_CHILD`	`domain_child`	`string`	Child zone name.
`B01_NO_CHILD`	`domain_super`	`string`	Next-higher domain suggested for testing.
`B01_PARENT_DISREGARDED`	`-`	`-`	No arguments.
`B01_PARENT_FOUND`	`domain`	`string`	Parent zone name candidate.
`B01_PARENT_FOUND`	`servers`	`array<object>`	Structured nameserver list returning parent evidence.
`B01_PARENT_NOT_FOUND`	`-`	`-`	No arguments.
`B01_PARENT_UNDETERMINED`	`servers`	`array<object>`	Structured nameserver list across competing parents.
`B01_ROOT_HAS_NO_PARENT`	`-`	`-`	No arguments.
`B01_SERVER_ZONE_ERROR`	`query_name`	`string`	Queried owner name that failed validation.
`B01_SERVER_ZONE_ERROR`	`rrtype`	`string`	Queried rrtype (`SOA` or `NS`).
`B01_SERVER_ZONE_ERROR`	`ns`	`string`	Nameserver identity (`ns` name only; use `address` for IP).
`B01_SERVER_ZONE_ERROR`	`address`	`string`	Nameserver IP address for the same endpoint.
`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 due to transport disable.
`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 over enabled transport.
`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 due to transport disable.
`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 over enabled transport.
`LOOP_PROTECTION`	`caller`	`string`	Internal caller name that hit loop protection.
`LOOP_PROTECTION`	`child_zone_name`	`string`	Child zone name under test.
`LOOP_PROTECTION`	`zone_name`	`string`	Current loop zone name state.
`LOOP_PROTECTION`	`intermediate_query_name`	`string`	Intermediate query name at stop point.
`TEST_CASE_END`	`testcase`	`string`	Testcase display name (`Basic01`).
`TEST_CASE_START`	`testcase`	`string`	Testcase display name (`Basic01`).

Severity Levels Per Tag

Tag	Level	Notes
`B01_CHILD_NOT_EXIST`	`INFO`	Default from `share/profile.json`.
`B01_CHILD_IS_ALIAS`	`NOTICE`	Default from `share/profile.json`.
`B01_CHILD_FOUND`	`INFO`	Default from `share/profile.json`.
`B01_INCONSISTENT_ALIAS`	`ERROR`	Default from `share/profile.json`.
`B01_INCONSISTENT_DELEGATION`	`ERROR`	Default from `share/profile.json`.
`B01_NO_CHILD`	`ERROR`	Default from `share/profile.json`.
`B01_PARENT_DISREGARDED`	`INFO`	Default from `share/profile.json`.
`B01_PARENT_FOUND`	`INFO`	Default from `share/profile.json`.
`B01_PARENT_NOT_FOUND`	`WARNING`	Default from `share/profile.json`.
`B01_PARENT_UNDETERMINED`	`WARNING`	Default from `share/profile.json`.
`B01_ROOT_HAS_NO_PARENT`	`INFO`	Default from `share/profile.json`.
`B01_SERVER_ZONE_ERROR`	`DEBUG`	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`.
`LOOP_PROTECTION`	`DEBUG2`	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: basic01.md
Differences (Upstream vs Gonemaster):
- Upstream: documents B01_NO_CHILD for the non-existing-child outcome. Gonemaster: also emits B01_CHILD_NOT_EXIST in fake-address mode.
- Upstream: testcase summary does not list transport debug tags or LOOP_PROTECTION. Gonemaster: emits IPV4_*, IPV6_*, and LOOP_PROTECTION.
Potential upstream report:
- yes
If yes, include:
- Upstream expected behavior: Child-not-exist path is described with B01_NO_CHILD only, and summary does not include transport or loop-protection tags.
- Gonemaster observed behavior: B01_CHILD_NOT_EXIST, transport tags, and LOOP_PROTECTION are possible emissions.
- evidence: engine/test/basic/basic.go (Basic01, ipDisabledMessage, ipEnabledMessage).
- report status: not filed

Implementation Notes

The following behaviors are implementation choices, not mandated by RFC 1034/1035:

Traversal strategy: The testcase probes iteratively from root servers using SOA, NS, and DNAME queries, extending the intermediate name toward the child zone at each step. The DNS protocol specifies the resolution model but does not define how a testcase tool should walk the hierarchy.
Sorted servers arguments: Nameserver lists passed in tag arguments are sorted before joining with ;. Deterministic ordering simplifies reproducible output but is not a protocol requirement.
Loop protection threshold: Traversal stops at a fixed internal limit and emits LOOP_PROTECTION. No DNS standard defines a specific iteration bound; the limit is a defensive implementation choice.

Edge Cases And Limitations

A missing recursor causes testcase execution error before completion.
Loop-protection fallback is defensive; when triggered it logs LOOP_PROTECTION and terminates the testcase early.
Child existence outcomes differ between normal and fake-address modes (B01_NO_CHILD vs B01_CHILD_NOT_EXIST).
Nameserver list argument order is deterministic because lists are sorted before join.