To mitigate DNS flood attacks over a single TCP connection, we throttle the connection when the other side does not read the data. Throttling should only occur on server-side sockets, but erroneously also happened for nsupdate, which acts as a client. When nsupdate started throttling the connection, it never attempts to read again. This has been fixed.
Closes#4910
Backport of MR !9709
Merge branch 'backport-4910-nsupdate-hangs-when-processing-large-update-9.20' into 'bind-9.20'
See merge request isc-projects/bind9!9834
The root cause is the fix for CVE-2024-0760 (part 3), which resets
the TCP connection on a failed send. Specifically commit
4b7c61381f stops reading on the socket
because the TCP connection is throttling.
When the tcpdns_send_cb callback thinks about restarting reading
on the socket, this fails because the socket is a client socket.
And nsupdate is a client and is using the same netmgr code.
This commit removes the requirement that the socket must be a server
socket, allowing reading on the socket again after being throttled.
(cherry picked from commit aa24b77d8b)
If ECDSAP256SHA256_SUPPORTED or ECDSAP384SHA384_SUPPORTED variables were
not present in the environment, os.environ would raise KeyError that is
not being handled in the decorator. Use os.getenv() instead.
(cherry picked from commit 1a5683b638)
The configuration option 'max-query-count' sets how many outgoing queries per client request is allowed. The existing 'max-recursion-queries' is the number of permissible queries for a single name and is reset on every CNAME redirection. This new option is a global limit on the client request. The default is 200.
This allows us to send a bit more queries while looking up a single name. The default for 'max-recursion-queries' is changed from 32 to 50.
Closes#4980Closes#4921
Backport of MR !9737
Merge branch 'backport-4980-global-limit-outgoing-queries-9.20' into 'bind-9.20'
See merge request isc-projects/bind9!9832
Changing the default for max-recursion-queries from 100 to 32 was too
strict in some cases, especially lookups in reverse IPv6 trees started
to fail more frequently. From issue #4921 it looks like 50 is a better
default.
Now that we have 'max-query-count' as a global limit of outgoing queries
per client request, we can increase the default for
'max-recursion-queries' again, as the number of recursive queries is
no longer bound by the multiple of 'max-recursion-queries' and
'max-query-restarts'.
(cherry picked from commit 84df920d9e)
This adds a new test directory specifically for CAMP attacks. This first
test in this test directory follows multiple CNAME chains, restarting
the max-recursion-queries counter, but should bail when the global
maximum quota max-query-count is reached.
(cherry picked from commit 73eafaba14)
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)
When returning zone statistics counters, the statistics sets are now attached while the zone is locked. This addresses Coverity warnings CID 468720, 468728 and 468729.
Closes#4934
Backport of MR !9488
Merge branch 'backport-4934-lock-and-attach-when-return-zone-stats-9.20' into 'bind-9.20'
See merge request isc-projects/bind9!9843
In dns_zone_getdnssecsignstats, dns_zone_getrcvquerystats and
dns_zone_getrequeststats attach to the statistics structure.
(cherry picked from commit fb50a71159)
Commit 4b3d0c6600 has removed them, but
did not remove few traces in documentation and help. Remove them from
remaining places.
Backport of MR !9606
Merge branch 'backport-main-memory-flags-size-mctx-9.20' into 'bind-9.20'
See merge request isc-projects/bind9!9842
Commit 4b3d0c6600 has removed them, but
did not remove few traces in documentation and help. Remove them from
remaining places.
(cherry picked from commit 65b9eeb39a)
`dnssec-signzone` was using revoked keys for signing RRsets other than DNSKEY. This has been corrected.
Closes#5070
Backport of MR !9800
Merge branch 'backport-5070-dnssec-signzone-fix-revoke-9.20' into 'bind-9.20'
See merge request isc-projects/bind9!9840
The ns2/managed1.conf file is created by the setup.sh script. Then, in
the tests.sh script it is moved to ns2/managed.conf. The latter file
name is in mkeys extra_artifacts, but the former one is not. This is a
problem when pytest is started with the --setup-only option as it only
runs the setup.sh script (e.g., in the cross-version-config-tests CI
job) and thus failing the "Unexpected files found" assertion.
Backport of MR !9815
Merge branch 'backport-mnowak/mkeys-add-ns2-managed1-conf-to-extra-artifacts-9.20' into 'bind-9.20'
See merge request isc-projects/bind9!9824
The ns2/managed1.conf file is created by the setup.sh script. Then, in
the tests.sh script it is moved to ns2/managed.conf. The latter file
name is in mkeys extra_artifacts, but the former one is not. This is a
problem when pytest is started with the --setup-only option as it only
runs the setup.sh script (e.g., in the cross-version-config-tests CI
job) and thus failing the "Unexpected files found" assertion.
(cherry picked from commit e7d973bd00)
When the resolver is trying to query an authority server and eventually timed out, a SERVFAIL answer is given to the client. Add the Extended DNS Error Code 22 - No Reachable Authority to the response.
Closes#2268
Backport of MR !9743
Merge branch 'backport-2268/ede-no-reachable-authority-9.20' into 'bind-9.20'
See merge request isc-projects/bind9!9814
Add support for Extended DNS Errors (EDE) error 22: No reachable
authority. This occurs when after a timeout delay when the resolver is
trying to query an authority server.
(cherry picked from commit d13e94b930)
Commit amended in order to fix usage of isc_log_write (adding dns_lctx
parameter)
Previously, the update policy rules check was moved earlier in the
sequence, and the keep rule match pointers were kept to maintain the
ability to verify maximum records by type.
However, these pointers can become invalid if server reloading
or reconfiguration occurs before update completion. To prevent
this issue, extract the maximum records by type value immediately
during processing and only keep the copy of the values instead of the
full ssurule.
(cherry picked from commit 44a54a29d8)
Release automation went wrong, it seems. And I just glanced over the
line, saw 4 -> 5 change at the end and did not notice the change at the
beginning of the line...
When release notes are generated, the text is wrapped and line breaks
are inserted into each paragraph (sourced from the commit message's
body). Prevent line breaks after hyphens, as these are often used for
option names. This makes it possible to easily find the options
afterwards.
Backport of MR !9801
Merge branch 'backport-nicki/gitchangelog-dont-break-on-hyphens-9.20' into 'bind-9.20'
See merge request isc-projects/bind9!9802
When release notes are generated, the text is wrapped and line breaks
are inserted into each paragraph (sourced from the commit message's
body). Prevent line breaks after hyphens, as these are often used for
option names. This makes it possible to easily find the options
afterwards.
(cherry picked from commit 9b0d0c0173)
In rbtdb.c, there were places where the code touched .references
directly instead of using the helper functions. Use the helper
functions instead.
Forward port from https://gitlab.isc.org/isc-private/bind9/-/merge_requests/753
Merge branch 'ondrej/use-attach-detach-in-rbtdb-9.20' into 'bind-9.20'
See merge request isc-projects/bind9!9795
There was a data race dns_validator_cancel() was called when the
offloaded operations were in progress. Make dns_validator_cancel()
respect the data ownership and only set new .canceling variable when
the offloaded operations are in progress. The cancel operation would
then finish when the offloaded work passes the ownership back to the
respective thread.
Closes#4926
Backport of MR !9470
Merge branch 'backport-4926-fix-data-race-in-dns_validator-9.20' into 'bind-9.20'
See merge request isc-projects/bind9!9790
There was a data race dns_validator_cancel() was called when the
offloaded operations were in progress. Make dns_validator_cancel()
respect the data ownership and only set new .shuttingdown variable when
the offloaded operations are in progress. The cancel operation would
then finish when the offloaded work passes the ownership back to the
respective thread.
(cherry picked from commit ee122ba025)
The SERVFAIL cache doesn't have a memory bound and the
cleaning of the old SERVFAIL cache entries was implemented
only in opportunistic manner. Improve the memory cleaning
of the SERVFAIL cache to be more aggressive, so it doesn't
consume a lot of memory in the case the server encounters
many SERVFAILs at once.
Closes#5025
Backport of MR !9760
Merge branch 'backport-5025-improve-badcache-cleaning-9.20' into 'bind-9.20'
See merge request isc-projects/bind9!9794
The lame-ttl processing was overriden to be disabled in the config,
but the code related to the lame-ttl was still kept in the resolver
code. More importantly, the DNS_RESOLVER_BADCACHETTL() macro would
cause the entries in the resolver badcache to be always cached for at
least 30 seconds even if the lame-ttl would be set to 0.
Remove the dns_badcache code from the dns_resolver unit, so we save some
processing time and memory in the resolver code.
(cherry picked from commit b61739836d)
Instead of cleaning the dns_badcache opportunistically, add per-loop
LRU, so each thread-loop can clean the expired entries. This also
allows removal of the atomic operations as the badcache entries are now
immutable, instead of updating the badcache entry in place, the old
entry is now deleted from the hashtable and the LRU list, and the new
entry is inserted in the LRU.
(cherry picked from commit 2cb5a6210f)
The nslookup system test checks the count of resolved addresses in
the CNAME tests using a 'grep' match on the hostname, and ignoring
lines containing the 'canonical name' string. In order to protect
the check from intermittent failures like the 'address in use' warning
message, which then automatically resolves after a retry, edit the
'grep' matching string to also ignore the comments (as the mentioned
warning message is a comment which contains the hostname).
Closes#4948
Backport of MR !9523
Merge branch 'backport-4948-nslookup-test-fix-9.20' into 'bind-9.20'
See merge request isc-projects/bind9!9791
The nslookup system test checks the count of resolved addresses in
the CNAME tests using a 'grep' match on the hostname, and ignoring
lines containing the 'canonical name' string. In order to protect
the check from intermittent failures like the 'address in use' warning
message, which then automatically resolves after a retry, edit the
'grep' matching string to also ignore the comments (as the mentioned
warning message is a comment which contains the hostname).
(cherry picked from commit 345b0f9e5c)
In some cases (there is evidence only when XoT was used) `named` failed
to try the next primary server in the list when the previous one was
marked as unreachable. This has been fixed.
Closes#5038
Backport of MR !9781
Merge branch 'backport-5038-xfr-primary-next-fix-9.20' into 'bind-9.20'
See merge request isc-projects/bind9!9788
