dns_db_findext() asserts if RRSIG is passed to it and
query_lookup_stale() failed to map RRSIG to ANY to prevent this. To
avoid cases like this in the future, move the mapping of SIG and RRSIG
to ANY for qctx->type to qctx_init().
(cherry picked from commit 56eae06418)
verify that updates are refused when the client is disallowed by
allow-query, and update forwarding is refused when the client is
is disallowed by update-forwarding.
verify that "too many DNS UPDATEs" appears in the log file when too
many simultaneous updates are processing.
(cherry picked from commit b91339b80e)
check allow-update, update-policy, and allow-update-forwarding before
consuming quota slots, so that unauthorized clients can't fill the
quota.
(this moves the access check before the prerequisite check, which
violates the precise wording of RFC 2136. however, RFC co-author Paul
Vixie has stated that the RFC is mistaken on this point; it should have
said that access checking must happen *no later than* the completion of
prerequisite checks, not that it must happen exactly then.)
(cherry picked from commit 964f559edb)
limit the number of simultaneous DNS UPDATE events that can be
processed by adding a quota for update and update forwarding.
this quota currently, arbitrarily, defaults to 100.
also add a statistics counter to record when the update quota
has been exceeded.
(cherry picked from commit 7c47254a14)
Previously, an incremental hash table resizing was implemented for the
dns_rbt_t hash table implementation. Using that as a base, also
implement the incremental hash table resizing also for isc_ht API
hashtables:
1. During the resize, allocate the new hash table, but keep the old
table unchanged.
2. In each lookup, delete, or iterator operation, check both tables.
3. Perform insertion operations only in the new table.
4. At each insertion also move <r> elements from the old table to
the new table.
5. When all elements are removed from the old table, deallocate it.
To ensure that the old table is completely copied over before the new
table itself needs to be enlarged, it is necessary to increase the
size of the table by a factor of at least (<r> + 1)/<r> during resizing.
In our implementation <r> is equal to 1.
The downside of this approach is that the old table and the new table
could stay in memory for longer when there are no new insertions into
the hash table for prolonged periods of time as the incremental
rehashing happens only during the insertions.
(cherry picked from commit e42cb1f198)
As shown in the previous commit, using sizeof(type_t) is a little
bit more error-prone when copy-pasting code, so extracting the
size information from the pointer which is being dealt with seems
like a better alternative.
(cherry picked from commit cf4003fa58)
Free 'sizeof(dns_forwarder_t)' bytes of memory instead of
'sizeof(dns_sockaddr_t)' bytes, because `fwd` is a pointer
to a 'dns_forwarder_t' type structure.
(cherry picked from commit 0cc1b06d98)
The dns_zonemgr_releasezone() function makes a decision to destroy
'zmgr' (based on its references count, after decreasing it) inside
a lock, and then destroys the object outside of the lock.
This causes a race with dns_zonemgr_detach(), which could destroy
the object in the meantime.
Change dns_zonemgr_releasezone() to detach from 'zmgr' and destroy
the object (if needed) using dns_zonemgr_detach(), outside of the
lock.
(cherry picked from commit c1fc212253)
Prefer the pthread_barrier implementation on platforms where it is
available over uv_barrier implementation. This also solves the problem
with thread sanitizer builds on macOS that doesn't have pthread barrier.
(cherry picked from commit d07c4a98da)
This reverts commit f17f5e831b that made
following change:
> The TLSDNS transport was not honouring the single read callback for
> TLSDNS client. It would call the read callbacks repeatedly in case the
> single TLS read would result in multiple DNS messages in the decoded
> buffer.
Turns out that this change broke XoT, so we are reverting the change
until we figure out a proper fix that will keep the design promise and
not break XoT at the same time.
The ns_client_aclchecksilent is used to check multiple ACLs before
the decision is made that a query is denied. It is also used to
determine if recursion is available. In those cases we should not
set the extended DNS error "Prohibited".
(cherry picked from commit 798c8f57d4)
Arthimetic on NULL pointers is undefined. Avoid arithmetic operations
when 'in' is NULL and require 'in' to be non-NULL if 'inlen' is not zero.
(cherry picked from commit 349c23dbb7)
DSCP has not been fully working since the network manager was
introduced in 9.16, and has been completely broken since 9.18.
This seems to have caused very few difficulties for anyone,
so we have now marked it as obsolete and removed the
implementation.
To ensure that old config files don't fail, the code to parse
dscp key-value pairs is still present, but a warning is logged
that the feature is obsolete and should not be used. Nothing is
done with configured values, and there is no longer any
range checking.
(cherry picked from commit 916ea26ead)
Commit 9ffb4a7ba1 causes Clang Static
Analyzer to flag a potential NULL dereference in query_nxdomain():
query.c:9394:26: warning: Dereference of null pointer [core.NullDereference]
if (!qctx->nxrewrite || qctx->rpz_st->m.rpz->addsoa) {
^~~~~~~~~~~~~~~~~~~
1 warning generated.
The warning above is for qctx->rpz_st potentially being a NULL pointer
when query_nxdomain() is called from query_resume(). This is a false
positive because none of the database lookup result codes currently
causing query_nxdomain() to be called (DNS_R_EMPTYWILD, DNS_R_NXDOMAIN)
can be returned by a database lookup following a recursive resolution
attempt. Add a NULL check nevertheless in order to future-proof the
code and silence Clang Static Analyzer.
(cherry picked from commit 07592d1315)
(cherry picked from commit a4547a1093)
With 'stale-answer-enable yes;' and 'stale-answer-client-timeout off;',
consider the following situation:
A CNAME record and its target record are in the cache, then the CNAME
record expires, but the target record is still valid.
When a new query for the CNAME record arrives, and the query fails,
the stale record is used, and then the query "restarts" to follow
the CNAME target. The problem is that the query's multiple stale
options (like DNS_DBFIND_STALEOK) are not reset, so 'query_lookup()'
treats the restarted query as a lookup following a failed lookup,
and returns a SERVFAIL answer when there is no stale data found in the
cache, even if there is valid non-stale data there available.
With this change, query_lookup() now considers non-stale data in the
cache in the first place, and returns it if it is available.
(cherry picked from commit 91a1a8efc5)
Prime the cache with the following records:
shortttl.cname.example. 1 IN CNAME longttl.target.example.
longttl.target.example. 600 IN A 10.53.0.2
Wait for the CNAME record to expire, disable the authoritative server,
and query 'shortttl.cname.example' again, expecting a stale answer.
(cherry picked from commit 537187bf2f)
Previously, dns_dispatch_gettcp() could pick a TCP connection created by
different thread - this breaks our contractual promise to DNS dispatch
by using the TCP connection on a different thread than it was created.
Add .tid member to the dns_dispatch_t struct and skip the dispatches
from other threads when looking up a TCP dispatch that we can reuse in
dns_request.
NOTE: This is going to be properly refactored, but this change could be
also backported to 9.18 for better stability and thread-affinity.
(cherry picked from commit 1a999353cd)
This bug was masked in the tests because the `catz` test script did an
`rndc addzone` before an `rndc delzone`. The `addzone` autovivified
the NZF config, so `delzone` worked OK.
This commit swaps the order of two sections of the `catz` test script
so that it uses `delzone` before `addzone`, which provokes a crash
when `delzone` requires a non-NULL NZF config.
To fix the crash, we now try to remove the zone from the NZF config
only if it was dynamically added but not by a catalog zone.
(cherry picked from commit 9fa20d6f6c)
If the isc_task_create_bound() fails in the middle of buckets
initialization - the most common case would be shutdown initialized
during reload, not all tasks would be initialized, but the cleanup
code would try to cleanup all buckets.
Make sure that we cleanup only the initialized buckets by setting
ntasks to the number of already initialized tasks on the error path.
The 'localaddr' pointer can be NULL, which causes an assertion failure.
Use '&disp->local' instead when printing a debug log message.
(cherry picked from commit 41ca9d419e)
