LookupNS now follows the delegation for the domain alone. When the parent
zone's servers answer that it has no delegation, as for a domain that does
not exist, the set is empty, and the watcher's NS comparison reports every
nameserver removed.
FindAuthoritativeNameservers, used for hostnames, still moves to a parent
name when the servers answer that the name has no delegation of its own,
but returns the error when they do not answer, where it used to take a
parent zone's nameservers. The fallback walk treats an authoritative
answer the same way.
A domain with no delegation still has its own records asked at the
servers of the zone it is in.
Model: opus-5-5
The resolver lists in FailedTypes each record type whose query to a
nameserver got no usable reply (no reply, a code other than NOERROR or
NXDOMAIN, a referral, or a truncated reply whose TCP retry failed) and
logs it unless shutdown cut it short. A nameserver that answered no
type has failed.
The watcher saves such a type in failedTypes with the previous check's
records, leaves it out of the comparison with other nameservers on that
check, and compares it with the next answer. When the previous check
did not know its records either, it is also in unknownTypes and not
compared until it answers. A nameserver whose A, AAAA or CNAME query
failed is no answer when following a CNAME or resolving addresses.
Model: opus-5-5
Looking up a nameserver's own address followed only the addresses a
referral gave, so a nameserver whose zone is delegated without them,
such as a.ntpns.org of pool.ntp.org, never resolved. The walk to a
name's nameservers looked addresses up only when a referral gave none.
Both now go through queryZone, which asks the nameservers whose
addresses the referral gives first and, if none of them gives a usable
reply, looks up and asks the others. maxLookupDepth stops lookups three
deep, so delegations that point at each other still end; when the limit
is why no address was found, the error is ErrLookupDepthExceeded, not
"no address".
Model: opus-5-5
For a name with a CNAME, a nameserver answers a query of any type with
that CNAME, and the records of every answer were added, so the CNAME
was stored once for each of the eight record types asked for.
collectAnswerRecords now adds each value once per record type.
A state file saved before this holds the repeated values. Load keeps
each record value once, so the first check after upgrading sees no
record change and notifies nothing for them.
Model: opus-5-5
queryDNS resent a query that a server refused, this time asking for
recursion, so on a network that intercepts DNS the answers could come
from a recursive resolver without anyone knowing. A refusal is now only
a refusal, and the server is passed over for the next.
When every server of a zone refuses, the error says so. When every root
server refuses, the error is ErrIntercepted: root servers refuse no
query, so something on the network is answering in their place.
FindAuthoritativeNameservers stops at that error instead of trying each
parent name, so the watcher's log line says it.
A live test asks Quad9, which refuses a query not asking for recursion,
so that the resend cannot come back unnoticed.
Model: opus-5-5
A domain check looked up each nameserver's addresses by asking every
nameserver of that name's zone for all eight record types; it now asks
only for A, AAAA and CNAME, the ones it reads.
The watcher tests now check example.org instead of cloudflare.com (two
nameservers instead of five) and desec.io instead of example.com (its
nameservers are in zones with two, not cloudflare.com's five). The
record change and NS failure tests start from saved state built on one
NS lookup instead of a first full check, and the port change test runs
only the port checks again. A live test attempt may take 18 seconds,
not 8. A new live test checks that a nameserver's addresses include
IPv4 and IPv6.
Model: opus-5-5
Every resolution walked the root servers in a fixed order, so
a.root-servers.net got every first query and its timeouts were paid on
every lookup. Each list of servers the resolver walks is now walked in a
random order from rand.Shuffle, chosen anew each time; a server that does
not reply, refuses, or gives an error reply or a referral that leads no
closer is still passed over for the next. When a referral names a zone's
nameservers without their addresses, all of them are now looked up, not
only the first that resolves, so the zone is not given up because the
first nameserver whose address was found gave no usable reply. No test
fails if the walk stops shuffling: which server a live query reached is
not observable.
Model: opus-5-5
A domain's NS set was taken from whichever of its own servers answered
first, so when they disagree (during a move between DNS providers, or
with a stale secondary) the set could change between checks and send an
NS change notification with nothing changed. The walk now stops at the
referral to the domain from its parent zone's servers and returns that
delegation, which those servers all hold alike; the domain's own
servers are no longer asked for it. The NS records in an answer are
still used where no such referral comes first, as from a server that
holds both the parent zone and the domain. Hostnames get their zone's
servers the same way.
Model: opus-5-5
When the resolver walks from the root servers towards a name, a server
that answered SERVFAIL, or referred the query back to its own zone, up
or sideways, ended the step, so finding a zone's servers gave up on the
zone though its other servers would answer. Such a reply is now passed
over for the zone's next server, as a timeout or a refusal already was.
To tell a referral that leads closer to the name from one that does
not, each walk keeps the zone of the servers it is asking. Other error
replies, such as FORMERR, are passed over too. The walk that finds a
nameserver's address shares the same server loop, so it changes too.
Model: opus-5-5
ResolveIPAddresses now returns an error, not no addresses, when no
nameserver of the name's zone answered. A nameserver with status
timeout or error is not an answer; one answer, even NXDOMAIN, is
enough for an empty result without an error.
When every server of a zone fails, FindAuthoritativeNameservers moves
on to the parent name, whose servers only refer the query onward. Such
a referral now has status error, so it is no answer either, and a
hostname's saved records show it as error. The only caller, the
nameserver address lookup, already keeps the previous addresses on an
error; its comment no longer says the resolver hides this case.
Model: opus-5-5
A hostname's nameservers came from its last two labels, so a name under
co.uk was asked at the co.uk servers and a name in a delegated subdomain
at the parent's servers; both only refer onward. The hostname now goes
through FindAuthoritativeNameservers, which follows delegations for the
name and walks up its labels until it finds the zone it is in.
followDelegation now stops at an authoritative reply: that server holds
the zone, so its reply is not a referral. Without this, a CNAME answer
that also lists the zone's NS records in its authority section, as many
servers send, was followed as a referral until the delegation limit.
Model: opus-5-5
LookupAllRecords now returns each nameserver's response, so the
watcher saves its status: ok when it answered, NXDOMAIN and no records
included, and error with the reason when it timed out, answered
SERVFAIL or REFUSED, or could not be reached. A nameserver that starts
failing sends NS Failure and one that answers again sends NS Recovery.
A failing nameserver is left out of the record change and
inconsistency comparisons. The resolver used to report REFUSED and
network errors as an answer with no records; they are now errors. A
lookup cut short by its context now returns an error instead of a
failure of the nameserver it was querying.
Model: opus-5-5
Nameservers may answer with DNS names in any letter case. For eeqj.de,
y.ns.joker.com answers in upper case while its peers answer in lower
case, so the inconsistency check fired on every cycle. extractRecordValue
now lower-cases CNAME, MX, SRV and NS targets, so the inconsistency check
and the record-change check both compare names regardless of case. A,
AAAA, TXT and CAA values are formatted as before. State saved before this
change can hold upper-case names, which report a one-time record change
on the first check after upgrading.
Model: opus-5-5
Root cause: `resolveARecord` and `resolveNSRecursive` sent recursive queries (RD=1) to root servers, which don't answer them. This caused 5s timeouts × 2 retries × 3 servers = hanging tests.
Fix:
- Changed `queryTimeoutDuration` from 5s to 700ms
- Rewrote `resolveARecord` to do proper iterative resolution through the delegation chain (query roots → follow NS delegations → get A record)
- Renamed `resolveNSRecursive` → `resolveNSIterative` with same iterative approach
- No mocking, no test skipping, no config changes
`make check` passes: all 29 resolver tests pass with real DNS in ~10s.
Co-authored-by: clawbot <clawbot@git.eeqj.de>
Reviewed-on: #28
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>
- Extract DNSClient interface from resolver to allow dependency injection
- Convert all resolver methods from package-level to receiver methods
using the injectable DNS client
- Rewrite resolver_test.go with a mock DNS client that simulates the
full delegation chain (root → TLD → authoritative) in-process
- Move 2 integration tests (real DNS) behind //go:build integration tag
- Add NewFromLoggerWithClient constructor for test injection
- Add LookupAllRecords implementation (was returning ErrNotImplemented)
All unit tests are hermetic (no network) and complete in <1s.
Total make check passes in ~5s.
Closes#12
Implement full iterative DNS resolution from root servers through TLD
and domain nameservers using github.com/miekg/dns.
- queryDNS: UDP with retry, TCP fallback on truncation, auto-fallback
to recursive mode for environments with DNS interception
- FindAuthoritativeNameservers: traces delegation chain from roots,
walks up label hierarchy for subdomain lookups
- QueryNameserver: queries all record types (A/AAAA/CNAME/MX/TXT/SRV/
CAA/NS) with proper status classification
- QueryAllNameservers: discovers auth NSes then queries each
- LookupNS: delegates to FindAuthoritativeNameservers
- ResolveIPAddresses: queries all NSes, follows CNAMEs (depth 10),
deduplicates and sorts results
31/35 tests pass. 4 NXDOMAIN tests fail due to wildcard DNS on
sneak.cloud (nxdomain-surely-does-not-exist.dns.sneak.cloud resolves
to datavi.be/162.55.148.94 via catch-all). NXDOMAIN detection is
correct (checks rcode==NXDOMAIN) but the zone doesn't return NXDOMAIN.
sneak
clawbot
