The dnstap system test fails intermittently, and it appears to be
a timing issue - adding a short delay after running 'fstrm_capture',
and before running 'dnstap -reopen' improves the situation from
50% failures (5 out of 10 times) to 0% failures (0 out of 20 times),
tested locally.
The reason is that 'fstrm_capture' is executed in the background,
and due to OS scheduling and other factors, the listener socket
may not be ready when the following command runs and tells 'named'
to (re)open it.
Dumping of the freshly transferred zone file can take some time.
Retry 5 times before failing.
The log excerpt below shows such a case, when dumping lasted more than
two seconds.
06-Mar-2023 09:32:09.973 zone example6/IN: Transfer started.
06-Mar-2023 09:32:10.301 zone example6/IN: zone transfer finished: success
06-Mar-2023 09:32:10.301 zone_dump: zone example6/IN: enter
06-Mar-2023 09:32:11.789 client @0x7fe9ab435d68 10.53.0.10#44113 (example6): AXFR request
06-Mar-2023 09:32:11.801 client @0x7fe9ab435d68 10.53.0.10#44113 (example6): transfer of 'example6/IN': AXFR ended: 5 messages, 2676 records, 55815 bytes, 0.011 secs (5074090 bytes/sec) (serial 1397051952)
06-Mar-2023 09:32:12.409 zone_gotwritehandle: zone example6/IN: enter
06-Mar-2023 09:32:12.421 dump_done: zone example6/IN: enter
06-Mar-2023 09:32:12.421 zone_journal_compact: zone example6/IN: target journal size 53044
There can be comments in dig output for a zone transfer only in case
of an error, so we should print those errors not when wait_for_tls_xfer
succeeds, but when it fails.
Also, there is no point in printing those comments when a failure was
indeed expected.
The serve-stale system test was intermittently failing due to a timing
issue:
I:serve-stale:check stale data.example TXT was refreshed...
I:serve-stale:failed
The RRset is refreshed, however, it first checks for an expected log
line, prior checking that the stale data.example TXT was refreshed
(using dig). This log line is there to ensure the record is actually
refreshed before we start querying again. Alternatively we could just
retry_quiet 10 <wait for dig output matches expectations>. It would
lower the chances for intermittent test failures, since there is no
longer a "check for log line, sleep one second if check fails, check
for log line, ...", prior to the check.
without diffie-hellman TKEY negotiation, some other code is
now effectively dead or unnecessary, and can be cleaned up:
- the rndc tsig-list and tsig-delete commands.
- a nonoperational command-line option to dnssec-keygen that
was documented as being specific to DH.
- the section of the ARM that discussed TKEY/DH.
- the functions dns_tkey_builddeletequery(), processdeleteresponse(),
and tkey_processgssresponse(), which are unused.
Completely remove the TKEY Mode 2 (Diffie-Hellman Exchanged Keying) from
BIND 9 (from named, named.conf and all the tools). The TKEY usage is
fringe at best and in all known cases, GSSAPI is being used as it should.
The draft-eastlake-dnsop-rfc2930bis-tkey specifies that:
4.2 Diffie-Hellman Exchanged Keying (Deprecated)
The use of this mode (#2) is NOT RECOMMENDED for the following two
reasons but the specification is still included in Appendix A in case
an implementation is needed for compatibility with old TKEY
implementations. See Section 4.6 on ECDH Exchanged Keying.
The mixing function used does not meet current cryptographic
standards because it uses MD5 [RFC6151].
RSA keys must be excessively long to achieve levels of security
required by current standards.
We might optionally implement Elliptic Curve Diffie-Hellman (ECDH) key
exchange mode 6 if the draft ever reaches the RFC status. Meanwhile the
insecure DH mode needs to be removed.
Named now logs both compile time and run time UV versions when
starting up. This is useful information to have when debugging
network issues involving named.
During reconfiguration, the configure_view() function reverts the
configured zones to the previous view in case if there is an error.
It uses the 'zones_configured' boolean variable to decide whether
it is required to revert the zones, i.e. the error happened after
all the zones were successfully configured.
The problem is that it does not account for the case when an error
happens during the configuration of one of the zones (not the first),
in which case there are zones that are already configured for the
new view (and they need to be reverted), and there are zones that
are not (starting from the failed one).
Since 'zones_configured' remains 'false', the configured zones are
not reverted.
Replace the 'zones_configured' variable with a pointer to the latest
successfully configured zone configuration element, and when reverting,
revert up to and including that zone.
The trick is to configure a duplicate zone, which comes after the
catalog zone, where the duplicate zone is an existing member zone.
In that scenario, all the zones which come before the "faulty" zone
in the configuration file will fail to be reverted to the previous
version of the view after a reconfiguration error, and in this
particular case that will result in an assertion failure when the
catalog zone update is initiated, because it will be still tied to
the new version of the view, which was dismissed.
Building the bin/tests/system/rpz/dnsrps helper binary is currently not
possible at all as the necessary compiler and linker flag definitions
are missing from bin/tests/system/Makefile.am. Add these as a basis for
addressing the problem.
Unfortunately, this is where the "mostly" bit mentioned in this commit's
subject line comes into play. The dlopen() parts of DNSRPS code have
not yet been reworked to use libuv's dlopen() API (uv_dlopen() etc.)
(See commit 37b9511ce1 for prior work in
this area.) While it is certainly possible to do that, implementing
such a change without testing it in practice against a usable librpz.so
(i.e. a DNSRPS provider library) is bound to cause more trouble and
confusion than keeping the code the way it is right now. However,
making that code buildable as-is requires linking against a C standard
library that exports the dlopen(), dlsym(), and dlclose() symbols used
by the DNSRPS dynamic loading code. glibc 2.34+ satisfies that
requirement, but older glibc versions do not (these come with a separate
libdl shared library that would need to be linked in as well). (Other
C standard library implementations have not been examined.) Since the
long-term plan is to rely on libuv's dlopen() API exclusively and
detecting the shared object containing dlopen() & friends would only
pull in build system complexity for no good reason, assume for now that
the target system provides the dlopen() API in its C standard library.
This change enables the system test suite to be run for a BIND 9 build
prepared using --enable-dnsrps --enable-dnsrps-dl (on systems satisfying
the requirement explained above). However, it is important to note that
this change by itself does NOT enable actual testing of the DNSRPS
feature as doing that requires a DNSRPS provider library to be present
on the test host.
This implements node reference tracing that passes all the internal
layers from dns_db API (and friends) to increment_reference() and
decrement_reference().
It can be enabled by #defining DNS_DB_NODETRACE in <dns/trace.h> header.
The output then looks like this:
incr:node:check_address_records:rootns.c:409:0x7f67f5a55a40->references = 1
decr:node:check_address_records:rootns.c:449:0x7f67f5a55a40->references = 0
incr:nodelock:check_address_records:rootns.c:409:0x7f67f5a55a40:0x7f68304d7040->references = 1
decr:nodelock:check_address_records:rootns.c:449:0x7f67f5a55a40:0x7f68304d7040->references = 0
There's associated python script to find the missing detach located at:
https://gitlab.isc.org/isc-projects/bind9/-/snippets/1038
Change the commandline option -G to take a string that determines what
sync records should be published. It is a comma-separated string with
each element being either "cdnskey", or "cds:<algorithm>", where
<algorithm> is a valid digest type. Duplicates are suppressed.
Now that we can configure a different digest type, update the code
to honor the configuration. Update 'dns_dnssec_syncupdate' so that
the correct CDS record is published, and also when deleting CDS records,
ensure that all possible CDS records are removed from the zone.
Change one of the test cases to use a different digest type (4). The
system tests and kasp script need to be updated to take into account
the new algorithm (instead of the hard coded 2).
The test was setting a minimum count for recursive clients which
was not always being met (e.g. 91 instead of 100) producing a false
positive. Lower the lower bound on recursive clients for this
test to 1.
Add the 'ixfr-from-differences yes;' option to trigger a failed
zone postload operation when a zone is updated but the serial
number is not updated, then issue two successive 'rndc reload'
commands to trigger the bug, which causes an assertion failure.
The configure_catz() function creates the catalog zones structure
for the view even when it is not needed, in which case it then
discards it (by detaching) later.
Instead, call dns_catz_new_zones() only when it is needed, i.e. when
there is no existing "previous" view with an existing 'catzs', that
is going to be reused.
* Change 'dns_catz_new_zones()' function's prototype (the order of the
arguments) to synchronize it with the similar function in rpz.c.
* Rename 'refs' to 'references' in preparation of ISC_REFCOUNT_*
macros usage for reference tracking.
* Unify dns_catz_zone_t naming to catz, and dns_catz_zones_t naming to
catzs, following the logic of similar changes in rpz.c.
* Use C compound literals for structure initialization.
* Synchronize the "new zone version came too soon" log message with the
one in rpz.c.
* Use more of 'sizeof(*ptr)' style instead of the 'sizeof(type_t)' style
expressions when allocating or freeing memory for 'ptr'.
`libirs` used to be a reference implementation of `getaddrinfo` and
related modern resolver APIs. It was stripped down in BIND 9.18
leaving only the `irs_resconf` module, which parses
`/etc/resolv.conf`. I have kept its include path and namespace prefix,
so it remains a little fragment of libirs now embedded in libdns.
the dns_xfrin module was still using the network manager directly to
manage TCP connections and send and receive messages. this commit
changes it to use the dispatch manager instead.
the 'dispatchmgr' member of the resolver object is used by both
the dns_resolver and dns_request modules, and may in the future
be used by others such as dns_xfrin. it doesn't make sense for it
to live in the resolver object; this commit moves it into dns_view.
the parser could crash when "include" specified an empty string in place
of the filename. this has been fixed by returning ISC_R_FILENOTFOUND
when the string length is 0.
Reproduce the assertion by configuring a 'named' resolver with
'recursive-clients 10;' configuration option and running 20
queries is parallel.
Also tweak the 'ans2/ans.pl' to simulate a 50ms network latency
when qname starts with "latency". This makes sure that queries
running in parallel don't get served immediately, thus allowing
the configured recursive clients quota limitation to be activated.
instead of using the SDB API as a wrapper to register and
unregister and provide a call framework for the builtin databases,
this commit flattens things so that the builtin databases implement
dns_db directly.
move all dns_sdb code into bin/named/builtin.c, which is the
only place from which it's called.
(note this is temporary: later we'll refactor builtin so that it's a
standalone dns_db implementation on its own instead of using SDB
as a wrapper.)
move database attach/detach functions to db.c, instead of
requiring them to be implemented for every database type.
instead, they must implement a 'destroy' function that is
called when references go to zero.
this enables us to use ISC_REFCOUNT_IMPL for databases,
with detailed tracing enabled by setting DNS_DB_TRACE to 1.
SDB is currently (and foreseeably) only used by the named
builtin databases, so it only needs as much of its API as
those databases use.
- removed three flags defined for the SDB API that were always
set the same by builtin databases.
- there were two different types of lookup functions defined for
SDB, using slightly different function signatures. since backward
compatibility is no longer a concern, we can eliminate the 'lookup'
entry point and rename 'lookup2' to 'lookup'.
- removed the 'allnodes' entry point and all database iterator
implementation code
- removed dns_sdb_putnamedrr() and dns_sdb_putnamedrdata() since
they were never used.
initialize dns_dbmethods, dns_sdbmethods and dns_rdatasetmethods
using explicit struct member names, so we don't have to keep track
of NULLs for unimplemented functions any longer.
some dns_db functions would have crashed if the DB implementation failed
to implement them, requiring the implementations to add functions that
did nothing but return ISC_R_NOTIMPLEMENTED or some obvious default
value. we can just have the dns_db wrapper functions themselves return
those values, and clean up the implementations accordingly.
When switching to a new view during a reconfiguration (or reverting
to the old view), detach the 'rpzs' and 'catzs' from the previuos view.
The 'catzs' case was earlier solved slightly differently, by detaching
from the new view when reverting to the old view, but we can not solve
this the same way for 'rpzs', because now in BIND 9.19 and BIND 9.18
a dns_rpz_shutdown_rpzs() call was added in view's destroy() function
before detaching the 'rpzs', so we can not leave the 'rpzs' attached to
the previous view and let it be shut down when we intend to continue
using it with the new view.
Instead, "re-fix" the issue for the 'catzs' pointer the same way as
for 'rpzs' for consistency, and also because a similar shutdown call
is likely to be implemented for 'catzs' in the near future.
this function was just a front-end for gethostname(). it was
needed when we supported windows, which has a different function
for looking up the hostname; it's not needed any longer.
