Colin Vidal [Mon, 27 Jan 2025 11:48:49 +0000 (11:48 +0000)]
fix: dev: fix EDE 22 time out detection
Extended DNS error 22 (No reachable authority) was previously detected when `fctx_expired` fired. It turns out this function is used as a "safety net" and the timeout detection should be caught earlier.
It was working though, because of another issue fixed by !9927. But then, the recursive request timed out detection occurs before `fctx_expired` making impossible to raise the EDE 22 error.
This fixes the problem by triggering the EDE 22 in the part of the code detecting the (TCP or UDP) time out and taking the decision to cancel the whole fetch (i.e. There is no other server to attempt to contact).
Note this is not targeting users (no release note) because there is no release versions of BIND between !9927 and this changes. Thus a release note would be confusing.
Colin Vidal [Fri, 24 Jan 2025 16:27:09 +0000 (17:27 +0100)]
fix byte order in EDE logging
When an EDE code is added to a message, the code is converted early in a
big-endian order so it can be memcpy-ed directly in the EDE buffer that
will go on the wire.
This previous change forget to update debug logs which still assume the
EDE code was in host byte order. Add a separate variable to
differentiate both and avoid ambiguities
Colin Vidal [Fri, 24 Jan 2025 10:23:43 +0000 (11:23 +0100)]
update serve-stale test to support EDE 22
When EDE 3 (stale answer) was added the serve-stale tests were checking
for those exclusively, i.e. grepping for no "EDE" in the dig output when
no stale answer was expected.
However, some stale tests disable stale answers and make the
authoritative server unresponsive, effectively triggering a timed out
request thus an EDE 22. Update those tests so they still tests the
absence of EDE 3 error, but also the presence of EDE 22.
Colin Vidal [Thu, 23 Jan 2025 15:43:53 +0000 (16:43 +0100)]
add new EDE 22 system tests
This re-do a previously existing EDE 22 system test as well as add
another one making sure the timed out flow detection works also on UDP
when the resolver is contacting the authoritative server. (the existing
test was using TCP to contact the authoritative servers).
Colin Vidal [Thu, 23 Jan 2025 15:38:35 +0000 (16:38 +0100)]
fix EDE 22 time out detection
Extended DNS error 22 (No reachable authority) was previously detected
when `fctx_expired` fired. It turns out this function is used as a
"safety net" and the timeout detection should be caught earlier.
It was working though, because of another issue fixed by !9927. Since
this change, the recursive request timed out detection occurs before
`fctx_expired` so EDE 22 is not added to the response message anymore.
The fix of the problem is to add the EDE 22 code in two situations:
- When the dispatch code timed out (rctx_timedout) the resolver code
checks various properties to figure out if it needs to make another
fetch attempt. One of the paramters if the fetch expiration time. If
it expires, the whole recursion is canceled, so it now adds the EDE 22
code.
- If the fetch expiration time doesn't expires in the case above (and
other parameters allows it) a new fetch attempt is made (fctx_query).
But before the new request is actually made, the fetch expiration time
is re-checked. It might then has elapsed, and the whole recursion is
canceled. So it now also adds the EDE 22 code here as well.
Aydın Mercan [Sat, 25 Jan 2025 12:53:38 +0000 (12:53 +0000)]
new: usr: add a rndc command to toggle jemalloc profiling
The new command is `rndc memprof`. The memory profiling status is also
reported inside `rndc status`. The status also shows whether named can
toggle memory profiling or not and if the server is built with jemalloc.
Closes #4759
Merge branch '4759-add-a-trigger-to-dump-jeprof-data-or-memory-statistics' into 'main'
Aydın Mercan [Mon, 12 Aug 2024 15:17:05 +0000 (18:17 +0300)]
add a rndc command to toggle jemalloc profiling
The new command is `rndc memprof`. The memory profiling status is also
reported inside `rndc status`. The status also shows whether named can
toggle memory profiling or not and if the server is built with jemalloc.
Nicki Křížek [Fri, 24 Jan 2025 18:10:32 +0000 (18:10 +0000)]
chg: ci: Ensure changelog job builds docs with the new entry
The changelog job is supposed to test that the text from GitLab MR
title&description is valid rst syntax and can be built with sphinx. In 49128fc1, the way gitchangelog generates entries was changed - it no
longer writes to the changelog file, but generates output on stdout
instead. Ensure the generated notes is actually written to (some)
rendered file which is part of the docs so that the subsequent sphinx
build attempts to render the note.
Merge branch 'nicki/ci-fix-changelog-job' into 'main'
Nicki Křížek [Mon, 2 Dec 2024 14:31:53 +0000 (15:31 +0100)]
Ensure changelog job builds docs with the new entry
The changelog job is supposed to test that the text from GitLab MR
title&description is valid rst syntax and can be built with sphinx. In 49128fc1, the way gitchangelog generates entries was changed - it no
longer writes to the changelog file, but generates output on stdout
instead. Ensure the generated notes is actually written to (some)
rendered file which is part of the docs so that the subsequent sphinx
build attempts to render the note.
Colin Vidal [Mon, 20 Jan 2025 19:59:23 +0000 (20:59 +0100)]
add DNSSEC EDE test for unsupported digest and alg
A DNSSEC validation can fail in the case where multiple DNSKEY are
available for a zone and none of them are supported, but for different
reasons: one has a DS record in the parent zone using an unsupported
digest while the other one uses an unsupported encryption algorithm.
Add a specific test case covering this flow and making sure that two
extended DNS error are provided: code 1 and 2, each of them highlighting
unsupported algorithm and digest.
Colin Vidal [Mon, 13 Jan 2025 13:50:01 +0000 (14:50 +0100)]
add support for EDE code 1 and 2
Add support for EDE codes 1 (Unsupported DNSKEY Algorithm) and 2
(Unsupported DS Digest Type) which might occurs during DNSSEC
validation in case of unsupported DNSKEY algorithm or DS digest type.
Because DNSSEC internally kicks off various fetches, we need to copy
all encountered extended errors from fetch responses to the fetch
context. Upon an event, the errors from the fetch context are copied
to the client response.
Nicki Křížek [Wed, 28 Aug 2024 13:00:02 +0000 (15:00 +0200)]
Make servers fixture in pytest module-wide
The servers are setup and torn down once per each test module. All the
logs and server state persists between individual tests within the same
module. The servers fixture representing these servers should be
module-wide as well.
Michal Nowak [Thu, 10 Oct 2024 17:46:22 +0000 (19:46 +0200)]
Use Debian "sid" for pylint and mypy jobs to get recent dnspython
The base image tends to have a rather old dnspython version and when
used with pylint and mypy it produces errors about newer dnspython
features the old version does not know about.
$ mypy "bin/tests/system/isctest/"
bin/tests/system/isctest/query.py:55: error: Unexpected keyword argument "verify" for "tls" [call-arg]
/usr/lib/python3/dist-packages/dns/query.py:958: note: "tls" defined here
Michal Nowak [Wed, 17 Jan 2024 19:47:42 +0000 (20:47 +0100)]
Add isctest.query.tls() function
When explicitly set to True, the "verify" argument lets dnspython verify
certificates used for the connection. As most certificates in the system
test will inevitably be self-signed, the "verify" argument defaults to
False.
The "verify" argument is present in dnspython since the version 2.5.0.
Evan Hunt [Fri, 24 Jan 2025 00:58:06 +0000 (00:58 +0000)]
rem: dev: Clean up unused result codes
A number of result codes are obsolete and can be removed. Others, including `ISC_R_NOMEMORY`, are still checked in various places even though they can't occur any longer. These have been cleaned up.
Evan Hunt [Thu, 9 Jan 2025 04:13:34 +0000 (20:13 -0800)]
deduplicate result codes
ISCCC_R_SYNTAX, ISCCC_R_EXPIRED, and ISCCC_R_CLOCKSKEW have the
same usage and text formats as DNS_R_SYNTAX, DNS_R_EXPIRED and
DNS_R_CLOCKSCREW respectively. this was originally done because
result codes were defined in separate libraries, and some tool
might be linked with libisccc but not libdns. as the result codes
are now defined in only one place, there's no need to retain the
duplicates.
Evan Hunt [Wed, 8 Jan 2025 21:50:53 +0000 (13:50 -0800)]
clean up uses of DST_R_NOCRYPTO
building BIND without crypto support is no longer possible.
consequently this result code is never sent, and therefore we
don't need code in calling functions to handle it.
Evan Hunt [Wed, 8 Jan 2025 03:03:07 +0000 (19:03 -0800)]
clean up uses of ISC_R_NOMEMORY
the isc_mem allocation functions can no longer fail; as a result,
ISC_R_NOMEMORY is now rarely used: only when an external library
such as libjson-c or libfstrm could return NULL. (even in
these cases, arguably we should assert rather than returning
ISC_R_NOMEMORY.)
code and comments that mentioned ISC_R_NOMEMORY have been
cleaned up, and the following functions have been changed to
type void, since (in most cases) the only value they could
return was ISC_R_SUCCESS:
(the exception is dns_view_create(), which could have returned
other error codes in the event of a crypto library failure when
calling isc_file_sanitize(), but that should be a RUNTIME_CHECK
anyway.)
Nicki Křížek [Thu, 23 Jan 2025 17:26:40 +0000 (17:26 +0000)]
chg: ci: Set stricter limits for respdiff testing
Adjust the limit of maximum disagreements in respdiff results based on
recent pipeline results.
The respdiff and respdiff:asan seem to have almost identical results,
typically around 0.07 % of differences with ocassional spikes up to
around 0.11 %. Similar results are for respdiff:tsan, perhaps with more
common spikes with values up to around 0.12 %. Set the limit to 0.15 %
to allow for some tolerance due to network conditions, time of day etc.
The respdiff:third-party has a slightly higher disagreements average,
with typical values being around 0.12 %. Set the limit to 0.2 %.
Exceeding either of those values should be quite clear indication that
some resolution behaviour has changed, since the values appear to be
very stable within the newly configured limits.
Merge branch 'nicki/ci-respdiff-limits' into 'main'
Nicki Křížek [Mon, 13 Jan 2025 13:29:24 +0000 (14:29 +0100)]
Set stricter limits for respdiff testing
Adjust the limit of maximum disagreements in respdiff results based on
recent pipeline results.
The respdiff and respdiff:asan seem to have almost identical results,
typically around 0.07 % of differences with ocassional spikes up to
around 0.11 %. Similar results are for respdiff:tsan, perhaps with more
common spikes with values up to around 0.12 %. Set the limit to 0.15 %
to allow for some tolerance due to network conditions, time of day etc.
The respdiff:third-party has a slightly higher disagreements average,
with typical values being around 0.12 %. Set the limit to 0.2 %.
Exceeding either of those values should be quite clear indication that
some resolution behaviour has changed, since the values appear to be
very stable within the newly configured limits.
Matthijs Mekking [Thu, 23 Jan 2025 11:12:33 +0000 (11:12 +0000)]
fix: doc: Clarify dnssec-signzone interval option
There was confusion about whether the interval was calculated from
the validity period provided on the command line (with -s and -e),
or from the signature being replaced.
Add text to clarify that the interval is calculated from the new
validity period.
Closes #5128
Merge branch '5128-clarify-dnssec-signzone-interval' into 'main'
Matthijs Mekking [Wed, 15 Jan 2025 12:47:48 +0000 (13:47 +0100)]
Clarify dnssec-signzone interval option
There was confusion about whether the interval was calculated from
the validity period provided on the command line (with -s and -e),
or from the signature being replaced.
Add text to clarify that the interval is calculated from the new
validity period.
Matthijs Mekking [Thu, 23 Jan 2025 10:36:15 +0000 (10:36 +0000)]
fix: usr: Fix a bug in dnssec-signzone related to keys being offline
In the case when `dnssec-signzone` is called on an already signed zone, and the private key file is unavailable, a signature that needs to be refreshed may be dropped without being able to generate a replacement. This has been fixed.
Closes #5126
Merge branch '5126-dnssec-signzone-retain-rrsig-if-key-is-offline' into 'main'
Matthijs Mekking [Tue, 14 Jan 2025 14:18:40 +0000 (15:18 +0100)]
dnssec-signzone retain signature if key is offline
Track inside the dns_dnsseckey structure whether we have seen the
private key, or if this key only has a public key file.
If the key only has a public key file, or a DNSKEY reference in the
zone, mark the key 'pubkey'. In dnssec-signzone, if the key only
has a public key available, consider the key to be offline. Any
signatures that should be refreshed for which the key is not available,
retain the signature.
So in the code, 'expired' becomes 'refresh', and the new 'expired'
is only used to determine whether we need to keep the signature if
the corresponding key is not available (retaining the signature if
it is not expired).
In the 'keysthatsigned' function, we can remove:
- key->force_publish = false;
- key->force_sign = false;
because they are redundant ('dns_dnsseckey_create' already sets these
values to false).
Matthijs Mekking [Tue, 14 Jan 2025 13:10:20 +0000 (14:10 +0100)]
Test dnssec-signzone with private key file missing
Add a test case for the scenario below.
There is a case when signing a zone with dnssec-signzone where the
private key file is moved outside the key directory (for offline
ksk purposes), and then the zone is resigned. The signature of the
DNSKEY needs refreshing, but is not expired.
Rather than removing the signature without having a valid replacement,
leave the signature in the zone (despite it needs to be refreshed).
Colin Vidal [Wed, 22 Jan 2025 21:32:28 +0000 (21:32 +0000)]
new: usr: Add support for multiple extended DNS errors
Extended DNS error mechanism (EDE) may have several errors raised during a DNS resolution. `named` is now able to add up to three EDE codes in a DNS response. In the case of duplicate error codes, only the first one will be part of the DNS response.
Colin Vidal [Tue, 14 Jan 2025 16:13:42 +0000 (17:13 +0100)]
add support for multiple EDE
Extended DNS error mechanism (EDE) enables to have several EDE raised
during a DNS resolution (typically, a DNSSEC query will do multiple
fetches which each of them can have an error). Add support to up to 3
EDE errors in an DNS response. If duplicates occur (two EDEs with the
same code, the extra text is not compared), only the first one will be
part of the DNS answer.
Because the maximum number of EDE is statically fixed, `ns_client_t`
object own a static vector of `DNS_DE_MAX_ERRORS` (instead of a linked
list, for instance). The array can be fully filled (all slots point to
an allocated `dns_ednsopt_t` object) or partially filled (or
empty). In such case, the first NULL slot means there is no more EDE
objects.
Arаm Sаrgsyаn [Wed, 22 Jan 2025 13:41:25 +0000 (13:41 +0000)]
chg: dev: Use a suitable response in tcp_connected() when initiating a read
When 'ISC_R_TIMEDOUT' is received in 'tcp_recv()', it times out the
oldest response in the active responses queue, and only after that it
checks whether other active responses have also timed out. So when
setting a timeout value for a read operation after a successful
connection, it makes sense to take the timeout value from the oldest
response in the active queue too, because, theoretically, the responses
can have different timeout values, e.g. when the TCP dispatch is shared.
Currently 'resp' is always NULL. Previously when connect and read timeouts
were not separated in dispatch this affected only logging, but now since
we are setting a new timeout after a successful connection, we need to
choose a suitable response from the active queue.
Merge branch 'aram/dispatch-tcp_connected-fix' into 'main'
Aram Sargsyan [Sat, 21 Dec 2024 09:10:20 +0000 (09:10 +0000)]
Clean up fctx->next_timeout
Since the support for non-zero values of stale-answer-client-timeout
was removed in bd7463914fe6375e3e9157f305c60d0172f2b312, 'next_timeout'
is unused. Clean it up.
Aram Sargsyan [Fri, 20 Dec 2024 10:39:26 +0000 (10:39 +0000)]
Adjust the resolver-query-timeout test
Since the read timeout now works, the resolver time outs from the
dispatch level instead of from the "hung fetch" timer, and so the
EDE value in 'fctx_expired()' is not being set. Remove the expected
EDE value from the test.
Aram Sargsyan [Fri, 20 Dec 2024 08:41:03 +0000 (08:41 +0000)]
Fix rtt calculation bug for TCP in the resolver
When TCP is used, 'fctx_query()' adds one second to the rtt
(round-trip time) value, but there's a bug when the decision
about using TCP is made already after the calculation. Move the
block of the code which looks up the peers list to decide
whether to use TCP into a place that's before the rtt calculation
is performed. This commit doesn't add or remove any code, it just
moves the code and adds a comment block.
Aram Sargsyan [Thu, 19 Dec 2024 14:22:54 +0000 (14:22 +0000)]
Use a suitable response in tcp_connected() when initiating a read
When 'ISC_R_TIMEDOUT' is received in 'tcp_recv()', it times out the
oldest response in the active responses queue, and only after that it
checks whether other active responses have also timed out. So when
setting a timeout value for a read operation after a successful
connection, it makes sense to take the timeout value from the oldest
response in the active queue too, because, theoretically, the responses
can have different timeout values, e.g. when the TCP dispatch is shared.
Currently 'resp' is always NULL. Previously when connect and read
timeouts were not separated in dispatch this affected only logging, but
now since we are setting a new timeout after a successful connection,
we need to choose a suitable response from the active queue.
Ondřej Surý [Wed, 22 Jan 2025 13:27:40 +0000 (13:27 +0000)]
fix: usr: Avoid unnecessary locking in the zone/cache database
Prevent lock contention among many worker threads referring to the same database node at the same time. This would improve zone and cache database performance for the heavily contended database nodes.
Closes #5130
Merge branch '5130-reduce-lock-contention-in-decrement-reference' into 'main'
JINMEI Tatuya [Sat, 18 Jan 2025 00:54:19 +0000 (16:54 -0800)]
Optimize database decref by avoiding locking with refs > 1
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.
Ondřej Surý [Wed, 15 Jan 2025 12:02:20 +0000 (13:02 +0100)]
Shutdown the fetch context after canceling the last fetch
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.
Ondřej Surý [Wed, 22 Jan 2025 13:14:40 +0000 (13:14 +0000)]
fix: usr: Apply the memory limit only to ADB database items
Resolver under heavy-load could exhaust the memory available for storing
the information in the Address Database (ADB) effectively evicting already
stored information in the ADB. The memory used to retrieve and provide
information from the ADB is now not a subject of the same memory limits
that are applied for storing the information in the Address Database.
Closes #5127
Merge branch '5127-change-ADB-memory-split' into 'main'
Ondřej Surý [Wed, 15 Jan 2025 09:36:33 +0000 (10:36 +0100)]
Remove memory limit on ADB finds and fetches
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.
Arаm Sаrgsyаn [Wed, 22 Jan 2025 12:58:29 +0000 (12:58 +0000)]
chg: dev: Separate the connect and the read TCP timeouts in dispatch
The network manager layer has two different timers with their
own timeout values for TCP connections: connect timeout and read
timeout. Separate the connect and the read TCP timeouts in the
dispatch module too.
Closes #5009
Merge branch '5009-dispatch-separate-connect-and-read-timeouts' into 'main'
Aram Sargsyan [Wed, 30 Oct 2024 13:31:34 +0000 (13:31 +0000)]
Remove dispatch timeout INT16_MAX limitation
In some places there was a limitation of the maximum timeout
value of INT16_MAX, which is only about 32 seconds. Refactor
the code to remove the limitation.
Aram Sargsyan [Wed, 30 Oct 2024 09:23:33 +0000 (09:23 +0000)]
Separate the connect and the read timeouts in dispatch
The network manager layer has two different timers with their
own timeout values for TCP connections: connect timeout and read
timeout. Separate the connect and the read TCP timeouts in the
dispatch module too.
Colin Vidal [Thu, 9 Jan 2025 11:01:28 +0000 (12:01 +0100)]
remove validator link form fetchctx
struct fetchctx does have a list of pending validators as well as a
pointer to the HEAD validator. Remove the validator pointer to avoid
confusion, as there is no perticular reasons to have it directly
accessible outside of the list.
Fix DNS-over-HTTP(S) implementation issues that arise under heavy
query load. Optimize resource usage for :iscman:`named` instances
that accept queries over DNS-over-HTTP(S).
Previously, :iscman:`named` would process all incoming HTTP/2 data
at once, which could overwhelm the server, especially when dealing
with clients that send requests but don't wait for responses. That
has been fixed. Now, :iscman:`named` handles HTTP/2 data in smaller
chunks and throttles reading until the remote side reads the
response data. It also throttles clients that send too many requests
at once.
Additionally, :iscman:`named` now carefully processes data sent by
some clients, which can be considered "flooding." It logs these
clients and drops connections from them.
:gl:`#4795`
In some cases, :iscman:`named` could leave DNS-over-HTTP(S)
connections in the `CLOSE_WAIT` state indefinitely. That also has
been fixed. ISC would like to thank JF Billaud for thoroughly
investigating the issue and verifying the fix.
:gl:`#5083`
See https://gitlab.isc.org/isc-projects/bind9/-/issues/4795
We started using isc_nm_bad_request() more actively throughout
codebase. In the case of HTTP/2 it can lead to a large count of
useless "Bad Request" messages in the BIND log, as often we attempt to
send such request over effectively finished HTTP/2 sessions.
Do not stop timer in isc_nm_read_stop() in manual timer mode
A call to isc_nm_read_stop() would always stop reading timer even in
manual timer control mode which was added with StreamDNS in mind. That
looks like an omission that happened due to how timers are controlled
in StreamDNS where we always stop the timer before pausing reading
anyway (see streamdns_on_complete_dnsmessage()). That would not work
well for HTTP, though, where we might want pause reading without
stopping the timer in the case we want to split incoming data into
multiple chunks to be processed independently.
I suppose that it happened due to NM refactoring in the middle of
StreamDNS development (at the time isc_nm_cancelread() and
isc_nm_pauseread() were removed), as the StreamDNS code seems to be
written as if timers are not stoping during a call to
isc_nm_read_stop().
This commit introduces manual read timer control as used by StreamDNS
and its underlying transports. Before that, DoH code would rely on the
timer control provided by TCP, which would reset the timer any time
some data arrived. Now, the timer is restarted only when a full DNS
message is processed in line with other DNS transports.
That change is required because we should not stop the timer when
reading from the network is paused due to throttling. We need a way to
drop timed-out clients, particularly those who refuse to read the data
we send.
This commit adds logic to make code better protected against clients
that send valid HTTP/2 data that is useless from a DNS server
perspective.
Firstly, it adds logic that protects against clients who send too
little useful (=DNS) data. We achieve that by adding a check that
eventually detects such clients with a nonfavorable useful to
processed data ratio after the initial grace period. The grace period
is limited to processing 128 KiB of data, which should be enough for
sending the largest possible DNS message in a GET request and then
some. This is the main safety belt that would detect even flooding
clients that initially behave well in order to fool the checks server.
Secondly, in addition to the above, we introduce additional checks to
detect outright misbehaving clients earlier:
The code will treat clients that open too many streams (50) without
sending any data for processing as flooding ones; The clients that
managed to send 1.5 KiB of data without opening a single stream or
submitting at least some DNS data will be treated as flooding ones.
Of course, the behaviour described above is nothing else but
heuristical checks, so they can never be perfect. At the same time,
they should be reasonable enough not to drop any valid clients,
realatively easy to implement, and have negligible computational
overhead.
DoH: process data chunk by chunk instead of all at once
Initially, our DNS-over-HTTP(S) implementation would try to process as
much incoming data from the network as possible. However, that might
be undesirable as we might create too many streams (each effectively
backed by a ns_client_t object). That is too forgiving as it might
overwhelm the server and trash its memory allocator, causing high CPU
and memory usage.
Instead of doing that, we resort to processing incoming data using a
chunk-by-chunk processing strategy. That is, we split data into small
chunks (currently 256 bytes) and process each of them
asynchronously. However, we can process more than one chunk at
once (up to 4 currently), given that the number of HTTP/2 streams has
not increased while processing a chunk.
That alone is not enough, though. In addition to the above, we should
limit the number of active streams: these streams for which we have
received a request and started processing it (the ones for which a
read callback was called), as it is perfectly fine to have more opened
streams than active ones. In the case we have reached or surpassed the
limit of active streams, we stop reading AND processing the data from
the remote peer. The number of active streams is effectively decreased
only when responses associated with the active streams are sent to the
remote peer.
Overall, this strategy is very similar to the one used for other
stream-based DNS transports like TCP and TLS.
Andoni Duarte [Wed, 15 Jan 2025 11:56:06 +0000 (11:56 +0000)]
[CVE-2024-11187] sec: usr: Limit the additional processing for large RDATA sets
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.
See isc-projects/bind9#5034
Merge branch '5034-security-limit-additional' into 'v9.21.4-release'
Ondřej Surý [Thu, 14 Nov 2024 09:37:29 +0000 (10:37 +0100)]
Limit the additional processing for large RDATA sets
Limit the number of records appended to ADDITIONAL section to the names
that have less than 14 records in the RDATA. This limits the number
of the lookups into the database(s) during single client query.
Also don't append any additional data to ANY queries. The answer to ANY
is already big enough.
Ondřej Surý [Tue, 7 Jan 2025 14:22:40 +0000 (15:22 +0100)]
Isolate using the -T noaa flag only for part of the resolver test
Instead of running the whole resolver/ns4 server with -T noaa flag,
use it only for the part where it is actually needed. The -T noaa
could interfere with other parts of the test because the answers don't
have the authoritative-answer bit set, and we could have false
positives (or false negatives) in the test because the authoritative
server doesn't follow the DNS protocol for all the tests in the resolver
system test.
Ondřej Surý [Thu, 14 Nov 2024 10:18:00 +0000 (11:18 +0100)]
Rename the qpzone and qpcache methods that implement DB api
All the database implementations share the same names for the methods
implementing the database. That has some advantages like knowing what
to expect, but it turns out that any time such method shows up in any
kind of tracing - be it perf record, backtrace or anything else that
uses symbol names, it is very hard to distinguish whether the find()
belongs to qpcache, qpzone, builtin or sdlz implementation.
Make at least the names for qpzone and qpcache unique.
Nicki Křížek [Tue, 14 Jan 2025 08:34:16 +0000 (08:34 +0000)]
fix: usr: querying an NSEC3-signed zone for an empty record could trigger an assertion
A bug in the qpzone database could trigger a crash when querying for a deleted name, or a newly-added empty non-terminal name, in an NSEC3-signed zone. This has been fixed.
Evan Hunt [Thu, 9 Jan 2025 02:08:05 +0000 (18:08 -0800)]
detect when closest-encloser name is too long
there was a database bug in which dns_db_find() could get a partial
match for the query name, but still set foundname to match the full
query name. this triggered an assertion when query_addwildcardproof()
assumed that foundname would be shorter.
the database bug has been fixed, but in case it happens again, we
can just copy the name instead of splitting it. we will also log a
warning that the closest-encloser name was invalid.
Evan Hunt [Sat, 21 Dec 2024 02:31:30 +0000 (18:31 -0800)]
dns_nsec3_addnsec3() can fail when iterating back
when adding a new NSEC3 record, dns_nsec3_addnsec3() uses a
dbiterator to seek to the newly created node and then find its
predecessor. dbiterators in the qpzone use snapshots, so changes
to the database are not reflected in an already-existing iterator.
consequently, when we add a new node, we have to create a new iterator
before we can seek to it.
Evan Hunt [Sat, 21 Dec 2024 01:25:10 +0000 (17:25 -0800)]
add a regression test for a new ENT node
this test adds a record with empty non-terminal nodes above it. this
has also been observed to trigger the crash in NSEC3 zones.
NOTE: the test currently fails, because while there is no crash, the
query results are not as expected. when we add a node below an ENT,
receive_secure_serial() gets DNS_R_PARTIALMATCH, and the signed
zone is never updated. this is not a regression from fixing the
crash bug; it's a separate inline-signing bug.
Evan Hunt [Thu, 19 Dec 2024 22:19:43 +0000 (14:19 -0800)]
qpzone find() function could set foundname incorrectly
when a requested name is found in the QP trie during a lookup, but its
records have been marked as nonexistent by a previous deletion, then
it's treated as a partial match, but the foundname could be left
pointing to the original qname rather than the parent. this could
lead to an assertion failure in query_findclosestnsec3().
Michał Kępień [Thu, 9 Jan 2025 11:16:48 +0000 (12:16 +0100)]
Fix default IANA root zone mirror configuration
Commit b121f02eac342ee285b6ab1292a0136448a91ee0 renamed the top-level
"primaries" block in bin/named/config.c to "remote-servers". This
configuration block lists the primary servers used for an IANA root zone
mirror when no primary servers are explicitly specified for it in the
configuration. However, the relevant part of the named_zone_configure()
function only looks for a top-level "primaries" block and not for any of
its synonyms. As a result, configuring an IANA root zone mirror with
just:
zone "." {
type mirror;
};
now results in a cryptic fatal error on startup:
loading configuration: not found
exiting (due to fatal error)
Fix by using the correct top-level block name in named_zone_configure().
Aram Sargsyan [Wed, 25 Dec 2024 14:30:53 +0000 (14:30 +0000)]
Don't disable RPZ and CATZ for zones with an $INCLUDE statement
The code in zone_startload() disables RPZ and CATZ for a zone if
dns_master_loadfile() returns anything other than ISC_R_SUCCESS,
which makes sense, but it's an error because zone_startload() can
also return DNS_R_SEENINCLUDE upon success when the zone had an
$INCLUDE statement.
projects / thirdparty / bind9.git / log
