resolver: query a hostname at its own zone's servers (closes #189)

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
2026-10-01 23:34:35 +02:00
parent c247f6bcf5
commit 797c936c48
4 changed files with 73 additions and 53 deletions
@@ -20,6 +20,8 @@ https://git.eeqj.de/sneak/dnswatcher/issues/149

 # Completed Steps

+- 2026-10-01: a hostname is queried at the servers of the zone it is in, found
+  by following delegations for the name, not its last two labels (closes #189).
 - 2026-10-01: each nameserver's addresses are saved with its domain, and a
  change while it stays in the delegation is notified (closes #105).
 - 2026-10-01: the watcher saves state when it stops, and shutdown waits for that