Delegation03

Status: Final

Purpose

• Check how large a synthesized maximal referral response is relative to the 512-byte non-EDNS UDP payload limit and the 1232-byte EDNS payload size, and grade it accordingly.

Preconditions And Inputs

• Preconditions:
  • A zone.Zone object is available.
• Required inputs:
  • Parent zone object from z.Parent(ctx).
  • Delegation NS names from z.GlueNames(ctx) .
  • Delegation addressed NS from GlueNameservers .
• Profile/config knobs that affect behavior:
  • No direct profile knob in this testcase.
  • Size thresholds are fixed by constants.UDPPayloadLimit (512) and constants.EDNSUDPPayloadDNSSECDefault (1232).

Algorithm And Decision Flow

1. Emit TEST_CASE_START.
2. Build a maximally long qname under the tested zone apex.
3. Build a DNS message with question <max-length-name> IN NS.
4. Add NS records for all names from z.GlueNames into the authority section.
5. Get parent zone from z.Parent(ctx); if parent is missing, return an error.
6. Read delegation addressed NS from GlueNameservers .
7. If IPv4 delegation NS list is non-empty and all names are in-bailiwick of parent:
   • Add one A glue record to additional section, using the first IPv4 nameserver.
8. If IPv6 delegation NS list is non-empty and all names are in-bailiwick of parent:
   • Add one AAAA glue record to additional section, using the first IPv6 nameserver.
9. Pack wire format with compression enabled and measure packet size.
10. Emit one of:
    • REFERRAL_SIZE_TOO_LARGE when packed size > 1232.
    • REFERRAL_SIZE_LARGE when packed size > 512 and <= 1232.
    • REFERRAL_SIZE_OK otherwise (packed size <= 512).
11. Emit TEST_CASE_END.

Synthetic Referral Build and Size Check (steps 2-11)

build qname = maxLengthNameFor(z.Name)   (FQDN padded to constants.FQDNMaxLength)
build msg with question <qname> IN NS

authority section:
   for each name in z.GlueNames -> add NS RR (owner = z.Name)

parent = z.Parent(ctx)
parent absent -> return error (testcase aborts)

delNS = GlueNameservers

additional section, A:
   nssV4 = filterByIPVersion(delNS, IPv4)
   nssV4 non-empty AND every NS name in nssV4 is in-bailiwick(parent.Name)
     -> add one A RR using nssV4[0]

additional section, AAAA:
   nssV6 = filterByIPVersion(delNS, IPv6)
   nssV6 non-empty AND every NS name in nssV6 is in-bailiwick(parent.Name)
     -> add one AAAA RR using nssV6[0]

pack msg with compression; size = len(packed)
   size >  constants.EDNSUDPPayloadDNSSECDefault (1232) -> REFERRAL_SIZE_TOO_LARGE (size)
   size >  constants.UDPPayloadLimit (512)              -> REFERRAL_SIZE_LARGE     (size)
   size <= 512                                          -> REFERRAL_SIZE_OK        (size)

emit TEST_CASE_END

Emitted Tags (Possible Set)

Tag Arguments

Severity Levels Per Tag

Differences From Upstream

• Differences (Upstream vs Gonemaster):
  • Upstream: describes adding one A/AAAA record with any address when conditions are met. Gonemaster: adds one record using the first available NS address from GlueNameservers for each family.
  • Upstream: does not describe testcase boundary debug markers. Gonemaster: emits TEST_CASE_START and TEST_CASE_END.
• Potential upstream report:
  • no

Edge Cases And Limitations

• This testcase does not send network queries; it evaluates synthesized packet size only.
• When a family has any out-of-bailiwick NS name relative to parent, no additional-section record is added for that family.
• A missing parent zone object is treated as a hard error instead of a logged result tag.