bind9/bin/tests/system/minimalresponses/common.py
Ondřej Surý 0c007d8659
Rename view->hints to view->rootdb and rearm priming
With the parent-centric resolver, dns_view_bestzonecut() consults the
delegation DB (view->deleg) rather than the main cache for the closest
zonecut.  Root is never the target of a referral, so it never lands in
delegdb; bestzonecut therefore falls through to the hints lookup on
every query whose closest ancestor is root.  prime_done() only called
dns_root_checkhints(), which logs discrepancies but does not update
any store bestzonecut looks at, so the fresh root NS records obtained
by priming were never used and priming kept re-firing.

Rename view->hints to view->rootdb and refresh it when a priming
fetch completes: the '.' NS rdataset is replaced with the fetched
one, and for each listed nameserver the matching A/AAAA glue is
copied from the response's ADDITIONAL section.  Only glue for names
that actually appear as NS targets is accepted, so a hostile response
cannot inject unrelated records.  Glue the response did not carry is
left untouched, so the hints-file records loaded at startup remain as
a fallback.

Each view gets its own rootdb: the previous shared
named_g_server->in_roothints is gone, and configure_view() calls
dns_rootns_create() per view when the class-IN defaults are needed.
That keeps the priming writer one-per-DB, so concurrent priming in
different views cannot race on the same zone-DB version.

The rootdb refresh runs synchronously from the resolver response path,
so records go straight from the wire into rootdb with no cache round
trip and no dependency on DNSSEC validation state.  A new
DNS_FETCHOPT_PRIMING option marks the priming fetch; prime_done()
itself is now pure cleanup.

Track the rootdb freshness window in view->rootdb_expires and trigger
re-priming lazily from dns_view_find() and bestzonecut_rootdb() only
when the window has elapsed.  Stale records are still served while the
fresh priming fetch is in flight.

Drop dns_root_checkhints() and its helpers; the rootdb is now the
authoritative source the resolver consults.
2026-04-16 13:39:18 +02:00

121 lines
5.5 KiB
Python

# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
#
# SPDX-License-Identifier: MPL-2.0
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, you can obtain one at https://mozilla.org/MPL/2.0/.
#
# See the COPYRIGHT file distributed with this work for additional
# information regarding copyright ownership.
# pylint: disable=global-statement
from re import compile as Re
from dns.rcode import NOERROR, REFUSED
import isctest
EXAMPLE2_NS = "example2. 300 IN NS ns.example2."
AEXAMPLE2_A = "a.example2. 300 IN A 10.53.0.20"
NSEXAMPLE2_A = "ns.example2. 300 IN A 10.53.0.2"
EXAMPLE4_NS = "example4. 300 IN NS ns.example4."
AEXAMPLE4_A = "a.example4. 300 IN A 10.53.0.40"
NSEXAMPLE4_A = "ns.example4. 300 IN A 10.53.0.4"
AROOTSERVER_NS = ". 300 IN NS a.root-servers.nil."
INPUTPARAMS = "ns, qname, qtype, rd, cached, rcode, answer, authority, additional"
# `minimal-responses yes` and `minimal-responses no-auth` behaves the same,
# hence they share the same input.
# The only case AUTHORITY and ADDITIONAL are provided are when strictly needed:
# - either from an authoritative server for delegation
# (cases with ns1, both AUTHORITY and glues in ADDITIONAL);
# - either from a resolver with RD=0 and no cache,
# so the resolver can only return the root hints (AUTHORITY only).
INPUTS_YES_NOAUTH = [
("ns1", "a.example2", "A", True, False, NOERROR, None, EXAMPLE2_NS, NSEXAMPLE2_A),
("ns1", "a.example4", "A", True, False, NOERROR, None, EXAMPLE4_NS, NSEXAMPLE4_A),
("ns2", "a.example2", "A", True, False, NOERROR, AEXAMPLE2_A, None, None),
("ns2", "a.example4", "A", True, False, REFUSED, None, None, None),
("ns3", "a.example2", "A", True, False, NOERROR, AEXAMPLE2_A, None, None),
("ns3", "a.example4", "A", True, False, NOERROR, AEXAMPLE4_A, None, None),
("ns3", "a.example2", "A", True, True, NOERROR, AEXAMPLE2_A, None, None),
("ns3", "a.example4", "A", True, True, NOERROR, AEXAMPLE4_A, None, None),
("ns4", "a.example2", "A", True, False, NOERROR, AEXAMPLE2_A, None, None),
("ns4", "a.example4", "A", True, False, NOERROR, AEXAMPLE4_A, None, None),
("ns4", "a.example2", "A", True, True, NOERROR, AEXAMPLE2_A, None, None),
("ns4", "a.example4", "A", True, True, NOERROR, AEXAMPLE4_A, None, None),
("ns1", "a.example2", "A", False, False, NOERROR, None, EXAMPLE2_NS, NSEXAMPLE2_A),
("ns1", "a.example4", "A", False, False, NOERROR, None, EXAMPLE4_NS, NSEXAMPLE4_A),
("ns2", "a.example2", "A", False, False, NOERROR, AEXAMPLE2_A, None, None),
("ns2", "a.example4", "A", False, False, REFUSED, None, None, None),
("ns3", "a.example2", "A", False, False, NOERROR, None, AROOTSERVER_NS, None),
("ns3", "a.example4", "A", False, False, NOERROR, None, AROOTSERVER_NS, None),
("ns3", "a.example2", "A", False, True, NOERROR, AEXAMPLE2_A, None, None),
("ns3", "a.example4", "A", False, True, NOERROR, AEXAMPLE4_A, None, None),
("ns4", "a.example2", "A", False, False, NOERROR, None, AROOTSERVER_NS, None),
("ns4", "a.example4", "A", False, False, NOERROR, AEXAMPLE4_A, None, None),
("ns4", "a.example2", "A", False, True, NOERROR, AEXAMPLE2_A, None, None),
("ns4", "a.example4", "A", False, True, NOERROR, AEXAMPLE4_A, None, None),
# Resolver always provides glues with associated NS for qtype=NS
("ns3", "example2", "NS", True, False, NOERROR, EXAMPLE2_NS, None, NSEXAMPLE2_A),
("ns3", "example2", "NS", False, False, NOERROR, None, AROOTSERVER_NS, None),
("ns3", "example2", "NS", False, True, NOERROR, EXAMPLE2_NS, None, NSEXAMPLE2_A),
("ns3", "example2", "NS", True, True, NOERROR, EXAMPLE2_NS, None, NSEXAMPLE2_A),
]
TESTSERVERS = None
FLUSHED_PATTERN = Re("flushing cache.*succeeded")
def check(ns, qname, qtype, rd, cached, rcode, answer, authority, additional):
ns = TESTSERVERS[ns]
msg = isctest.query.create(qname, qtype, rd=rd)
if cached:
cachingmsg = isctest.query.create(qname, qtype, rd=True)
isctest.query.udp(cachingmsg, ns.ip)
else:
with ns.watch_log_from_here() as watcher:
ns.rndc("flush")
watcher.wait_for_line(FLUSHED_PATTERN)
res = isctest.query.udp(msg, ns.ip)
isctest.check.rcode(res, rcode)
if answer:
assert len(res.answer) == 1
# Clamp the answer TTL to 300 to match the expected answer
# (In case the server would be a bit slow to process the
# query, and we would end up with a TTL of ~299)
res.answer[0].ttl = 300
assert str(res.answer[0]) == answer
else:
assert len(res.answer) == 0
if authority:
assert len(res.authority) == 1
assert str(res.authority[0]) == authority
else:
assert len(res.authority) == 0
if additional:
assert len(res.additional) == 1
# Clamp the answer TTL to 300 to match the expected answer
# (In case the server would be a bit slow to process the
# query, and we would end up with a TTL of ~299)
res.additional[0].ttl = 300
assert str(res.additional[0]) == additional
else:
assert len(res.additional) == 0
def reconfig(servers, templates, minresp):
global TESTSERVERS
for server in servers:
ns = servers[server]
with ns.watch_log_from_here() as watcher:
templates.render(f"{server}/named.conf", {"minresp": minresp})
ns.rndc("reload")
watcher.wait_for_line("running")
TESTSERVERS = servers