Since mirror zone data is treated as cache data for access control
purposes, configuring a mirror zone and disabling recursion at the same
time would effectively prevent mirror zone data from being used since
disabling recursion also disables cache access to all clients by
default. Even though this behavior can be inhibited by configuration,
mirror zones are a recursive resolver feature and thus recursion is now
required to use them.
Ignore the fact that certain configurations might still trick named into
assuming recursion is enabled when it effectively is not since this
change is not meant to put a hard policy in place but rather just to
prevent accidental mirror zone misuse.
Previous way of handling NOTIFY settings for mirror zones was a bit
tricky: any value of the "notify" option was accepted, but it was
subsequently overridden with dns_notifytype_explicit. Given the way
zone configuration is performed, this resulted in the following
behavior:
- if "notify yes;" was set explicitly at any configuration level or
inherited from default configuration, it was silently changed and so
only hosts specified in "also-notify", if any, were notified,
- if "notify no;" was set at any configuration level, it was
effectively honored since even though zone->notifytype was silently
set to dns_notifytype_explicit, the "also-notify" option was never
processed due to "notify no;" being set.
Effectively, this only allowed the hosts specified in "also-notify" to
be notified, when either "notify yes;" or "notify explicit;" was
explicitly set or inherited from default configuration.
Clean up handling of NOTIFY settings for mirror zones by:
- reporting a configuration error when anything else than "notify no;"
or "notify explicit;" is set for a mirror zone at the zone level,
- overriding inherited "notify yes;" setting with "notify explicit;"
for mirror zones,
- informing the user when the "notify" setting is overridden, unless
the setting in question was inherited from default configuration.
Use a zone's 'type' field instead of the value of its DNS_ZONEOPT_MIRROR
option for checking whether it is a mirror zone. This makes said zone
option and its associated helper function, dns_zone_mirror(), redundant,
so remove them. Remove a check specific to mirror zones from
named_zone_reusable() since another check in that function ensures that
changing a zone's type prevents it from being reused during
reconfiguration.
Commit ba91243542 causes the resolver to
respond to a client query with FORMERR when all upstream queries sent to
the servers authoritative for QNAME elicit FORMERR responses. This
happens because resolver code returns DNS_R_FORMERR in such a case and
dns_result_torcode() acts as a pass-through for all arguments which are
already a valid RCODE.
The correct RCODE to set in the response returned to the client in the
case described above is SERVFAIL. Make sure this happens by overriding
the RCODE in query_gotanswer(), on the grounds that any format errors in
the client query itself should be caught long before execution reaches
that point. This change should not reduce query error logging accuracy
as the resolver code itself reports the exact reason for returning a
DNS_R_FORMERR result using log_formerr().
- the text returned by "rndc nta" when adding NTAs to multiple views
was incorrectly terminated after the first line, so users only saw
on NTA added unless they checked the logs.
This properly orders clearing the freed pointer and calling isc_refcount_destroy
as early as possible to have ability to put proper memory barrier when cleaning
up reference counting.
Force ns3 to use a constant source address (10.53.0.3) when sending
transfer requests for the "initially-unavailable" zone to prevent
failures of transfers not triggered by bin/tests/system/mirror/tests.sh
from causing fallback to using a source address for which transfers of
that zone are refused throughout the entire "mirror" system test since
that might yield false positives.
A short time window exists between logging the addition of an NSEC3PARAM
record to a zone and committing it to the current version of the zone
database. If a query arrives during such a time window, an unsigned
response will be returned. One of the checks in the "inline" system
test requires NSEC3 records to be present in an answer - that check
would fail in the case described above. Use rndc instead of log
watching for checking whether zone signing and NSEC3 chain modifications
are complete in order to prevent intermittent "inline" system test
failures.
While "rndc reload" causes dns_zone_asyncload() to be called for the
signed version of an inline-signed zone, the subsequent zone_load() call
causes the raw version to be reloaded from storage. This means that
DNS_ZONEFLG_LOADPENDING gets set for the signed version of the zone by
dns_zone_asyncload() before the reload is attempted, but zone_postload()
is only called for the raw version and thus DNS_ZONEFLG_LOADPENDING is
cleared for the raw version, but not for the signed version. This in
turn prevents zone maintenance from happening for the signed version of
the zone.
Until commit 29b7efdd9f, this problem
remained dormant because DNS_ZONEFLG_LOADPENDING was previously
immediately, unconditionally cleared after zone loading was started
(whereas it should only be cleared when zone loading is finished or an
error occurs). This behavior caused other issues [1] and thus had to be
changed.
Fix reloading inline-signed zones by clearing DNS_ZONEFLG_LOADPENDING
for the signed version of the zone once the raw version reload
completes. Take care not to clear it prematurely during initial zone
load. Also make sure that DNS_ZONEFLG_LOADPENDING gets cleared when
zone_postload() encounters an error or returns early, to prevent other
scenarios from resulting in the same problem. Add comments aiming to
help explain code flow.
[1] see RT #47076
Michał KępieńandOndřej Surý
Witold KręcickiandEvan Hunt
Mark AndrewsandWitold Kręcicki