dns_adb_flushname() calls dns_name_hash() to determine the ADB bucket
number to search for the given name. Meanwhile, all other functions in
lib/dns/adb.c call dns_name_fullhash() for determining the bucket number
instead. This discrepancy causes dns_adb_flushname() to have virtually
no chances of actually removing the given name from the ADB if the
name is longer than 16 bytes (since dns_name_hash() only hashes the
first 16 bytes of the name provided to it) - more specifically, the
probability of success for names longer than 16 bytes is inversely
proportional to the number of ADB buckets in use, i.e. 1:1021 at best.
Fix by using dns_name_fullhash() instead of dns_name_hash() in
dns_adb_flushname(), so that the logic for determining the bucket number
that a given name belongs to is consistent throughout lib/dns/adb.c.
When canceling the last fetch, we also need to stop the fctx_expired
timer from possibly firing between the fctx_shutdown() call and the
fetch being actually destroyed along with the timer. As there are
multiple places where fctx_shutdown() is being called without stopping
the timer, move the fctx_stoptimer() to fctx_shutdown() and cleanup the
explicit usage.
Address Database (ADB) shares the memory for the short lived ADB
objects (finds, fetches, addrinfo) and the long lived ADB
objects (names, entries, namehooks). This could lead to a situation
where the resolver-heavy load would force evict ADB objects from the
database to point where ADB is completely empty, leading to even more
resolver-heavy load.
Make the short lived ADB objects use the other memory context that we
already created for the hashmaps. This makes the ADB overmem condition
to not be triggered by the ongoing resolver fetches.
(cherry picked from commit 05faff6d53)
When the recursive-clients value is too large, the linked lists holding
the fetch contexts can also grow large and since the algorithm to merge
outgoing queries is quadratic, named can get slow.
Replace the linked list with hashtable for faster lookups. This also
allows us to reduce the number of tasks (buckets) in the resolver.
Previously, this function always acquires a node write lock if it
might need node cleanup in case the reference decrements to 0. In
fact, the lock is unnecessary if the reference is larger than 1 and it
can be optimized as an "easy" case. This optimization could even be
"necessary". In some extreme cases, many worker threads could repeat
acquring and releasing the reference on the same node, resulting in
severe lock contention for nothing (as the ref wouldn't decrement to 0
in most cases). This change would prevent noticeable performance
drop like query timeout for such cases.
Co-authored-by: JINMEI Tatuya <jtatuya@infoblox.com>
Co-authored-by: Ondřej Surý <ondrej@isc.org>
(cherry picked from commit 7f4471594d)
Currently, the fetch context will continue running even when the last
fetch (response) has been removed from the context, so named can process
and cache the answer. This can lead to a situation where the number of
outgoing recursing clients exceeds the the configured number for
recursive-clients.
Be more stringent about the recursive-clients limit and shutdown the
fetch context immediately after the last fetch has been canceled from
that particular fetch context.
The last remaining tuning value was RESOLVER_NTASKS and instead of
having variable number of the tasks per-cpu and in named and in
dns_client, set the number of the resolver tasks to 523 (number taken
from dns_client unit) to accomodate most of the recursive-clients
values.
When answering queries, don't add data to the additional section if
the answer has more than 13 names in the RDATA. This limits the
number of lookups into the database(s) during a single client query,
reducing query processing load.
Also, don't append any additional data to type=ANY queries. The
answer to ANY is already big enough.
(cherry picked from commit a1982cf1bb)
Commit af7db89513 as part of #4141 was
supposed to apply the 'max-recursion-queries' quota to validator
queries, but the counter was never actually passed on to
dns_resolver_createfetch(). This has been fixed, and the global query
counter ('max-query-count', per client request) is now also added.
(cherry picked from commit 5b1ae4a948)
While implementing the global limit 'max-query-count', initially I
thought adding the variable to the resolver structure. But the limit
is per client request so it was moved to the view structure (and
counter in ns_query structure). However, I forgot to remove the
variable from the resolver structure again. This commit fixes that.
(cherry picked from commit 397ca34e34)
This global limit is not reset on query restarts and is a hard limit
for any client request.
Note: This commit has been significantly modified because of many
merge conflicts due to the dns_resolver_createfetch api changes.
(cherry picked from commit 16b3bd1cc7)
Add another option to configure how many outgoing queries per
client request is allowed. The existing 'max-recursion-queries' is
per restart, this one is a global limit.
(cherry picked from commit bbc16cc8e6)
DNS_LOGMODULE_RBTDB was simply inappropriate, and this
log message is actually dependent on db implementation
details, so DNS_LOGMODULE_DB would be the best choice.
(cherry picked from commit b0309ee631)
The new log message is emitted when adding or updating an RRset
fails due to exceeding the max-records-per-type limit. The log includes
the owner name and type, corresponding zone name, and the limit value.
It will be emitted on loading a zone file, inbound zone transfer
(both AXFR and IXFR), handling a DDNS update, or updating a cache DB.
It's especially helpful in the case of zone transfer, since the
secondary side doesn't have direct access to the offending zone data.
It could also be used for max-types-per-name, but this change
doesn't implement it yet as it's much less likely to happen
in practice.
(cherry picked from commit 4156995431)
The DLZ modules are poorly maintained as we only ensure they can still
be compiled, the DLZ interface is blocking, so anything that blocks the
query to the database blocks the whole server and they should not be
used except in testing. The DLZ interface itself should be scheduled
for removal.
(cherry picked from commit a6cce753e2)
The 'dns' variable in dohpath can be in various forms ({?dns},
{dns}, {&dns} etc.). To check for a valid dohpath it ends up
being simpler to just parse the URI template rather than looking
for all the various forms if substring.
(cherry picked from commit af54ef9f5d)
Prior to running the keymgr, first make sure that existing keys
are present in the new keylist. If not, treat this as an operational
error where the keys are made offline (temporarily), possibly unwanted.
(cherry picked from commit 5fdad05a8a)
Static-stub address and addresses from other sources where being
mixed together resulting in static-stub queries going to addresses
not specified in the configuration or alternatively static-stub
addresses being used instead of the real addresses.
(cherry picked from commit b3a2c790f3)
The 'all_spilled' local variable in resolver.c:fctx_getaddresses()
is 'true' by default, and only becomes false when there is at least
one successfully found NS address. However, when a 'forward only;'
configuration is used, the code jumps over the part where it looks
for NS addresses and doesn't reset the 'all_spilled' to false, which
results in incorretly increased 'serverquota' statistics variable,
and also in invalid return error code from the function. The result
code error didn't make any differences, because all codes other than
'ISC_R_SUCCESS' or 'DNS_R_WAIT' were treated in the same way, and
the result code was never logged anywhere.
Set the default value of 'all_spilled' to 'false', and only make it
'true' before actually starting to look up NS addresses.
(cherry picked from commit e430ce7039)
This change allows fallback from an IXFR failure to AXFR when the
reason is DNS_R_TOOMANYRECORDS. This is because this error condition
could be temporary only in an intermediate version of IXFR
transactions and it's possible that the latest version of the zone
doesn't have that condition. In such a case, the secondary would never
be able to update the zone (even if it could) without this fallback.
This fallback behavior is particularly useful with the recently
introduced max-records-per-type and max-types-per-name options:
the primary may not have these limitations and may temporarily
introduce "too many" records, breaking IXFR. If the primary side
subsequently deletes these records, this fallback will help recover
the zone transfer failure automatically; without it, the secondary
side would first need to increase the limit, which requires more
operational overhead and has its own adverse effect.
This change also fixes a minor glitch that DNS_R_TOOMANYRECORDS wasn't
logged in xfrin_fail.
(cherry picked from commit 7289090683)
Return partial match from dns_db_find/dns_db_find when requested
to short circuit the closest encloser discover process. Most of the
time this will be the actual closest encloser but may not be when
there yet to be committed / cleaned up versions of the zone with
names below the actual closest encloser.
(cherry picked from commit d42ea08f16)
If there is an algorithm rollover and two keys of different algorithm
share the same keytags, then there is a possibility that if we check
that a key matches a specific state, we are checking against the wrong
key.
Fix this by not only checking for matching key id but also key
algorithm.
(cherry picked from commit f37eb33f29)
openssleddsa_isprivate failed to properly determine if a buffer was
private or not. Pass in a buffer so that EVP_PKEY_get_raw_private_key
fails when there is not a private key.
During a reconfiguration named doesn't reconfigure catalog zones
member zones. Implement the necessary code to reconfigure catz
member zones.
(cherry picked from commit fd71ed5d73ae2dc968e8782ce652fb8ef257c25e)
MAX_RESTARTS is no longer hard-coded; ns_server_setmaxrestarts()
and dns_client_setmaxrestarts() can now be used to modify the
max-restarts value at runtime. in both cases, the default is 11.
(cherry picked from commit c5588babaf)
the number of steps that can be followed in a CNAME chain
before terminating the lookup has been reduced from 16 to 11.
(this is a hard-coded value, but will be made configurable later.)
(cherry picked from commit 05d78671bb)
previously, validator queries for DNSKEY and DS records were
not counted toward the quota for max-recursion-queries; they
are now.
(cherry picked from commit af7db89513)
there were cases in resolver.c when queries for NS records were
started without passing a pointer to the parent fetch's query counter;
as a result, the max-recursion-queries quota for those queries started
counting from zero, instead of sharing the limit for the parent fetch,
making the quota ineffective in some cases.
(cherry picked from commit d3b7e92783)
Instead of randomly using -1 or 1 as a failure status, properly utilize
the EXIT_FAILURE define that's platform specific (as it should be).
(cherry picked from commit76997983fde02d9c32aa23bda30b65f1ebd4178c)
when a priming query is complete, it's currently logged at
level ISC_LOG_INFO, regardless of success or failure. we
are now changing it to ISC_LOG_NOTICE in the case of failure
and ISC_LOG_DEBUG(1) in case of success.
(cherry picked from commit a84d54c6ff)
Decrementing optlen immediately before calling continue is unneccesary
and inconsistent with the rest of dns_message_pseudosectiontoyaml
and dns_message_pseudosectiontotext. Coverity was also reporting
an impossible false positive overflow of optlen (CID 499061).
4176 } else if (optcode == DNS_OPT_CLIENT_TAG) {
4177 uint16_t id;
4178 ADD_STRING(target, "; CLIENT-TAG:");
4179 if (optlen == 2U) {
4180 id = isc_buffer_getuint16(&optbuf);
4181 snprintf(buf, sizeof(buf), " %u\n", id);
4182 ADD_STRING(target, buf);
CID 499061: (#1 of 1): Overflowed constant (INTEGER_OVERFLOW)
overflow_const: Expression optlen, which is equal to 65534, underflows
the type that receives it, an unsigned integer 16 bits wide.
4183 optlen -= 2;
4184 POST(optlen);
4185 continue;
4186 }
4187 } else if (optcode == DNS_OPT_SERVER_TAG) {
(cherry picked from commit 47338c2c87)
The period between the most significant nibble of the IPv4 address
and the 2.0.0.2.IP6.ARPA suffix was missing resulting in the wrong
name being checked.
(cherry picked from commit bca63437a1)
In yaml mode we emit a string for each question and record. Certain
names and data could result in invalid yaml being produced. Use single
quote string for all questions and records. This requires that single
quotes get converted to two quotes within the string.
(cherry picked from commit 393d7fa78e)
ALPN are defined as 1*255OCTET in RFC 9460. commatxt_fromtext was not
rejecting invalid inputs produces by missing a level of escaping
which where later caught be dns_rdata_fromwire on reception.
These inputs should have been rejected
svcb in svcb 1 1.svcb alpn=\,abc
svcb1 in svcb 1 1.svcb alpn=a\,\,abc
and generated 00 03 61 62 63 and 01 61 00 02 61 62 63 respectively.
The correct inputs to include commas in the alpn requires double
escaping.
svcb in svcb 1 1.svcb alpn=\\,abc
svcb1 in svcb 1 1.svcb alpn=a\\,\\,abc
and generate 04 2C 61 62 63 and 06 61 2C 2C 61 62 63 respectively.
(cherry picked from commit b51c9eb797)
Michał Kępień
Andoni Duarte Pintado
Ondřej Surý
Mark Andrews
JINMEI TatuyaandOndřej Surý
Matthijs Mekking
Remi GacogneandMark Andrews
Nicki KřížekandOndřej Surý
Aram SargsyanandMark Andrews
Michal Nowak
Evan Hunt