Don't attempt to resolve DNS responses for intermediate results. This
may create multiple refreshes and can cause a crash.
One scenario is where for the query there is a CNAME and canonical
answer in cache that are both stale. This will trigger a refresh of
the RRsets because we encountered stale data and we prioritized it over
the lookup. It will trigger a refresh of both RRsets. When we start
recursing, it will detect a recursion loop because the recursion
parameters will eventually be the same. In 'dns_resolver_destroyfetch'
the sanity check fails, one of the callers did not get its event back
before trying to destroy the fetch.
Move the call to 'query_refresh_rrset' to 'ns_query_done', so that it
is only called once per client request.
Another scenario is where for the query there is a stale CNAME in the
cache that points to a record that is also in cache but not stale. This
will trigger a refresh of the RRset (because we encountered stale data
and we prioritized it over the lookup).
We mark RRsets that we add to the message with
DNS_RDATASETATTR_STALE_ADDED to prevent adding a duplicate RRset when
a stale lookup and a normal lookup conflict with each other. However,
the other non-stale RRset when following a CNAME chain will be added to
the message without setting that attribute, because it is not stale.
This is a variant of the bug in #2594. The fix covered the same crash
but for stale-answer-client-timeout > 0.
Fix this by clearing all RRsets from the message before refreshing.
This requires the refresh to happen after the query is send back to
the client.
(cherry picked from commit d939d2ecde)
Limit the amount of database lookups that can be triggered in
fctx_getaddresses() (i.e. when determining the name server addresses to
query next) by setting a hard limit on the number of NS RRs processed
for any delegation encountered. Without any limit in place, named can
be forced to perform large amounts of database lookups per each query
received, which severely impacts resolver performance.
The limit used (20) is an arbitrary value that is considered to be big
enough for any sane DNS delegation.
(cherry picked from commit 3a44097fd6)
It is possible to bypass Response Rate Limiting (RRL)
`responses-per-second` limitation using specially crafted wildcard
names, because the current implementation, when encountering a found
DNS name generated from a wildcard record, just strips the leftmost
label of the name before making a key for the bucket.
While that technique helps with limiting random requests like
<random>.example.com (because all those requests will be accounted
as belonging to a bucket constructed from "example.com" name), it does
not help with random names like subdomain.<random>.example.com.
The best solution would have been to strip not just the leftmost
label, but as many labels as necessary until reaching the suffix part
of the wildcard record from which the found name is generated, however,
we do not have that information readily available in the context of RRL
processing code.
Fix the issue by interpreting all valid wildcard domain names as
the zone's origin name concatenated to the "*" name, so they all will
be put into the same bucket.
(cherry picked from commit baa9698c9d)
The zone 'retransfer3.' tests whether zones that 'rndc signing
-nsec3param' requests are queued even if the zone is not loaded.
The test assumes that if 'rndc signing -list' shows that the zone is
done signing with two keys, and there are no NSEC3 chains pending, the
zone is done handling the '-nsec3param' queued requests. However, it
is possible that the 'rndc signing -list' command is received before
the corresponding privatetype records are added to the zone (the records
that are used to retrieve the signing status with 'rndc signing').
This is what happens in test failure
https://gitlab.isc.org/isc-projects/bind9/-/jobs/2722752.
The 'rndc signing -list retransfer3' is thus an unreliable check.
It is simpler to just remove the check and wait for a certain amount
of time and check whether ns3 has re-signed the zone using NSEC3.
(cherry picked from commit 8b71cbd09c)
previously, if ns_clientmgr_create() failed, the interface was not
cleaned up correctly and an assertion or segmentation fault could
follow. this has been fixed.
The usage of xmlInitThreads() and xmlCleanupThreads() functions in
libxml2 is now marked as deprecated, and these functions will be made
private in the future.
Use xmlInitParser() and xmlCleanupParser() instead of them.
(cherry picked from commit a5d412d924)
Having implicit inline-signing set for dnssec-policy when there is no
update policy is confusing, so lets make this explicit.
(cherry picked from commit 5ca02fe6e7e591d1fb85936ea4dda720c3d741ef)
In several cases where IDNA2008 mappings do not exist whereas IDNA2003
mappings do, dig was failing to process the suplied domain name. Take a
backwards compatible approach, and convert the domain to IDNA2008 form,
and if that fails try the IDNA2003 conversion.
(cherry picked from commit 10923f9d87)
This should make sure that the memory context is not destroyed
before the memory pool, which is using the context.
(cherry picked from commit e97c3eea95)
YAML strings should be quoted if they contain colon characters.
Since IPv6 addresses do, we now quote the query_address and
response_address strings in all YAML output.
(cherry picked from commit 66eaf6bb73)
The dnstap query_message field was in some cases being filled in
with response messages, along with the response_message field.
The query_message field should only be used when logging requests,
and the response_message field only when logging responses.
