The isc_nm_pause(), isc_nm_resume() and finishing the nm_thread() from
nm_destroy() has been refactored, so all use the netievents instead of
directly touching the worker structure members. This allows us to
remove most of the locking as the .paused and .finished members are
always accessed from the matching nm_thread.
When shutting down the nm_thread(), instead of issuing uv_stop(), we
just shutdown the .async handler, so all uv_loop_t events are properly
finished first and uv_run() ends gracefully with no outstanding active
handles in the loop.
Since Mac OS X 10.1, Mach-O object files are by default built with a
so-called two-level namespace which prevents symbol lookups in BIND unit
tests that attempt to override the implementations of certain library
functions from working as intended. This feature can be disabled by
passing the "-flat_namespace" flag to the linker. Fix unit tests
affected by this issue on macOS by adding "-flat_namespace" to LDFLAGS
used for building all object files on that operating system (it is not
enough to only set that flag for the unit test executables).
As currently used in the BIND source tree, the --wrap linker option is
redundant because:
- static builds are no longer supported,
- there is no need to wrap around existing functions - what is
actually required (at least for now) is to replace them altogether
in unit tests,
- only functions exposed by shared libraries linked into unit test
binaries are currently being replaced.
Given the above, providing the alternative implementations of functions
to be overridden in lib/ns/tests/nstest.c is a much simpler alternative
to using the --wrap linker option. Drop the code detecting support for
the latter from configure.ac, simplify the relevant Makefile.am, and
remove lib/ns/tests/wrap.c, updating lib/ns/tests/nstest.c accordingly
(it is harmless for unit tests which are not calling the overridden
functions).
RPZ rules cannot be fully relied upon until the summary RPZ database is
updated after an "rndc reload". Wait until the relevant message is
logged after an "rndc reload" to prevent false positives in the
"rpzrecurse" system test caused by the RPZ rules not yet being in effect
by the time ns3 is queried.
The typical sequence of events for AAAA queries which trigger recursion
for an A RRset at the same name is as follows:
1. Original query context is created.
2. An AAAA RRset is found in cache.
3. Client-specific data is allocated from the filter-aaaa memory pool.
4. Recursion is triggered for an A RRset.
5. Original query context is torn down.
6. Recursion for an A RRset completes.
7. A second query context is created.
8. Client-specific data is retrieved from the filter-aaaa memory pool.
9. The response to be sent is processed according to configuration.
10. The response is sent.
11. Client-specific data is returned to the filter-aaaa memory pool.
12. The second query context is torn down.
However, steps 6-12 are not executed if recursion for an A RRset is
canceled. Thus, if named is in the process of recursing for A RRsets
when a shutdown is requested, the filter-aaaa memory pool will have
outstanding allocations which will never get released. This in turn
leads to a crash since every memory pool must not have any outstanding
allocations by the time isc_mempool_destroy() is called.
Fix by creating a stub query context whenever fetch_callback() is called,
including cancellation events. When the qctx is destroyed, it will ensure
the client is detached and the plugin memory is freed.
By changing the check in 'rdatasetiter_first' and 'rdatasetiter_next'
from "now > header->rdh_ttl" to "now - RBDTB_VIRTUAL > header->rdh_ttl"
we include expired rdataset entries so that they can be used for
"rndc dumpdb -expired".
Minor changes are:
- Replace the "$RNDCCMD dumpdb" logic with "rndc_dumpdb" from
conf.sh.common (it does the same thing).
- Update a comment to match the grep calls below it (comment said the
rest should be expired, while the grep calls indicate that they
are still in the cache, the comment now explains why).
The message buffer passed to ns__client_request is only valid for
the life of the the ns__client_request call. Save a copy of it
when we recurse or process a update as ns__client_request will
return before those operations complete.
The dotat() function has been changed to send the TAT
query asynchronously, so there's no lock order loop
because we initialize the data first and then we schedule
the TAT send to happen asynchronously.
This breaks following lock-order loops:
zone->lock (dns_zone_setviewcommit) while holding view->lock
(dns_view_setviewcommit)
keytable->lock (dns_keytable_find) while holding zone->lock
(zone_asyncload)
view->lock (dns_view_findzonecut) while holding keytable->lock
(dns_keytable_forall)
As the query_prefetch() or query_rpzfetch() could be called during
"regular" fetch, we need to introduce separate storage for attaching
the nmhandle during prefetching the records. The query_prefetch()
and query_rpzfetch() are guarded for re-entrance by .query.prefetch
member of ns_client_t, so we can reuse the same .prefetchhandle for
both.
The size of the log generated by each GitLab CI job is limited to 4 MB
by default. While this limit is configurable, it makes little sense to
print build logs to standard output if they are being captured to files
anyway. Limit use of "tee" in util/pairwise-testing.sh to printing the
combination of configure switches used for a given build. This way the
job should never exceed the default 4 MB log size limit, yet it will
still indicate its progress in a concise way.
Include the log file generated by the last failed pairwise build among
the artifacts produced by the "pairwise" GitLab CI job in order to
simplify troubleshooting pairwise build failures.
Pairwise testing is a test case generation technique based on the
observation that most faults are caused by interactions of at most two
factors. For BIND, its configure options can be thought of as such
factors.
Process BIND configure options into a model that is subsequently
processed by the PICT tool in order to find an effective test vector.
That test vector is then used for configuring and building BIND using
various combinations of configure options.
Each dns_rpz_zone_t structure keeps a hash table of the names this RPZ
database contains. Here is what happens when an RPZ is updated:
- a new hash table is prepared for the new version of the RPZ by
iterating over it; each name found is added to the summary RPZ
database,
- every name added to the new hash table is searched for in the old
hash table; if found, it is removed from the old hash table,
- the old hash table is iterated over; all names found in it are
removed from the summary RPZ database (because at that point the old
hash table should only contain names which are not present in the
new version of the RPZ),
- the new hash table replaces the old hash table.
When the new version of the RPZ is iterated over, if a given name is
spelled using a different letter case than in the old version of the
RPZ, the new variant will hash to a different value than the old
variant, which means it will not be removed from the old hash table.
When the old hash table is subsequently iterated over to remove
seemingly deleted names, the old variant of the name will still be
there, causing the name to be deleted from the summary RPZ database
(which effectively causes a given rule to be ignored).
The issue can be triggered not just by altering the case of existing
names in an RPZ, but also by adding sibling names spelled with a
different letter case. This is because RBT code preserves case when
node splitting occurs. The end result is that when the RPZ is iterated
over, a given name may be using a different case than in the zone file
(or XFR contents).
Fix by downcasing all names found in the RPZ database before adding them
to the summary RPZ database.
Add an item to the release checklist to make sure eligible customers get
notified about the location of the latest version of BIND Subscription
Edition upon its release.
No issues with the glue cache feature have been reported since its
introduction in BIND 9.12. As the rationale for introducing the
"glue-cache" option was to have a safety switch readily available in
case the glue cache turns out to cause problems, it is time to deprecate
the option. Glue cache will be permanently enabled in a future release,
at which point the "glue-cache" option will be made obsolete.
The clang 12 has a new warning that warns when using multi-line strings
in the string arrays, f.e.:
{ "aa",
"b"
"b",
"cc" }
would generate warning like this:
private_test.c:162:7: error: suspicious concatenation of string literals in an array initialization; did you mean to separate the elements with a comma? [-Werror,-Wstring-concatenation]
"33333/RSASHA1" };
^
private_test.c:161:7: note: place parentheses around the string literal to silence warning
"Done removing signatures for key "
^
private_test.c:197:7: error: suspicious concatenation of string literals in an array initialization; did you mean to separate the elements with a comma? [-Werror,-Wstring-concatenation]
"NSEC chain",
^
private_test.c:196:7: note: place parentheses around the string literal to silence warning
"Removing NSEC3 chain 1 0 30 DEAF / creating "
^
2 errors generated.
If NETMGR_TRACE is defined, we now maintain a list of active sockets
in the netmgr object and a list of active handles in each socket
object; by walking the list and printing `backtrace` in a debugger
we can see where they were created, to assist in in debugging of
reference counting errors.
On shutdown, if netmgr finds there are still active sockets after
waiting, isc__nm_dump_active() will be called to log the list of
active sockets and their underlying handles, along with some details
about them.
if more than 10 seconds pass while we wait for netmgr events to
finish running on shutdown, something is almost certainly wrong
and we should assert and crash.
Attaching and detaching handle pointers will make it easier to
determine where and why reference counting errors have occurred.
A handle needs to be referenced more than once when multiple
asynchronous operations are in flight, so callers must now maintain
multiple handle pointers for each pending operation. For example,
ns_client objects now contain:
- reqhandle: held while waiting for a request callback (query,
notify, update)
- sendhandle: held while waiting for a send callback
- fetchhandle: held while waiting for a recursive fetch to
complete
- updatehandle: held while waiting for an update-forwarding
task to complete
control channel connection objects now contain:
- readhandle: held while waiting for a read callback
- sendhandle: held while waiting for a send callback
- cmdhandle: held while an rndc command is running
httpd connections contain:
- readhandle: held while waiting for a read callback
- sendhandle: held while waiting for a send callback
- rename isc_nmsocket_t->tcphandle to statichandle
- cancelread functions now take handles instead of sockets
- add a 'client' flag in socket objects, currently unused, to
indicate whether it is to be used as a client or server socket
some versions of perl failed to run packet.pl because the 'last'
keyword can't be used outside of a loop block. this commit changes
the packet dumping code to a function so we can use 'return' instead.
the tcp system test uses the 'packet.pl' test tool to send a packet
thousands of times. this took a long time because the tool was waiting
for replies and parsing them; however, for that particular test the
replies aren't relevant.
this commit uses non-blocking sockets and moves the reply parsing
outside the send loop, which speeds the system test up substantially.
As generated documentation files are no longer stored in the BIND Git
repository, put a copy of the PDF version of the BIND ARM generated by
the "docs" GitLab CI job into the Windows zips to make it easily
available to the end users on that platform.
Make sure Windows zips also contain certain documentation files included
in source tarballs to make the contents of each release more consistent
across different platforms.
The "huge.zone" zone can take longer than 100 seconds to load when
running under a sanitizer. Increase the relevant zone load timeout to
prevent intermittent failures of the "rndc" system test.
The CDS/CDNSKEY record will be published when the DS is in the
rumoured state. However, with the introduction of the rndc '-checkds'
command, the logic in the keymgr was changed to prevent the DS
state to go in RUMOURED unless the specific command was given. Hence,
the CDS was never published before it was seen in the parent.
Initially I thought this was a policy approval rule, however it is
actually a DNSSEC timing rule. Remove the restriction from
'keymgr_policy_approval' and update the 'keymgr_transition_time'
function. When looking to move the DS state to OMNIPRESENT it will
no longer calculate the state from its last change, but from when
the DS was seen in the parent, "DS Publish". If the time was not set,
default to next key event of an hour.
Similarly for moving the DS state to HIDDEN, the time to wait will
be derived from the "DS Delete" time, not from when the DS state
last changed.
The 'rndc_checkds' utility now allows "now" as the time when the DS
has been seen in/seen removed from the parent.
Also it uses "KEYX" as the key argument, rather than key id.
The 'rndc_checkds' will retrieve the key from the "KEYX" string. This
makes the call a bit more readable.
This commit has a lot of updates on comments, mainly to make the
system test more readable.
Also remove some redundant signing policy checks (check_keys,
check_dnssecstatus, check_keytimes).
Finally, move key time checks and expected key time settings above
'rndc_checkds' calls (with the new way of testing next key event
times there is no need to do them after 'rndc_checkds', and moving
them above 'rndc_checkds' makes the flow of testing easier to follow.
Add two more arguments to the dnssec-settime tool. '-P ds' sets the
time that the DS was published in the parent, '-D ds' sets the time
that the DS was removed from the parent (these times are not accurate,
but rely on the user to use them appropriately, and as long as the
time is not before actual publication/withdrawal, it is fine).
These new arguments are needed for the kasp system test. We want to
test when the next key event is once a DS is published, and now
that 'parent-registration-delay' is obsoleted, we need a different
approach to reliable test the timings.
This switch is believed to be unnecessary. The possibility to use
gperftools CPU profiler was kept, one needs to set 'CFLAGS' and
'LDFLAGS' accordingly.
The test works as follows:
1. Client wants to resolve unusual ip6.arpa. name:
test1.test2.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.9.0.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. IN TXT
2. Query is sent to ns7, a qmin enabled resolver.
3. ns7 do the first stage in query minimization for the name and send a new
query to root (ns1):
_.1.0.0.2.ip6.arpa. IN A
4. ns1 delegates ip6.arpa. to ns2.good.:
;; AUTHORITY SECTION:
;ip6.arpa. 20 IN NS ns2.good.
;; ADDITIONAL SECTION:
;ns2.good. 20 IN A 10.53.0.2
5. ns7 do a second round in minimizing the name and send a new query
to ns2.good. (10.53.0.2):
_.8.2.6.0.1.0.0.2.ip6.arpa. IN A
6. ans2 delegates 8.2.6.0.1.0.0.2.ip6.arpa. to ns3.good.:
;; AUTHORITY SECTION:
;8.2.6.0.1.0.0.2.ip6.arpa. 60 IN NS ns3.good.
;; ADDITIONAL SECTION:
;ns3.good. 60 IN A 10.53.0.3
7. ns7 do a third round in minimizing the name and send a new query to
ns3.good.:
_.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. IN A
8. ans3 delegates 1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. to ns4.good.:
;; AUTHORITY SECTION:
;1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. 60 IN NS ns4.good.
;; ADDITIONAL SECTION:
;ns4.good. 60 IN A 10.53.0.4
9. ns7 do fourth round in minimizing the name and send a new query to
ns4.good.:
_.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. IN A
10. ns4.good. doesn't know such name, but answers stating it is authoritative for
the domai:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 53815
...
;; AUTHORITY SECTION:
1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. 60 IN SOA ns4.good. ...
11. ns7 do another minimization on name:
_.9.0.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa
sends to ns4.good. and gets the same SOA response stated in item #10
12. ns7 do another minimization on name:
_.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.9.0.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa
sends to ns4.good. and gets the same SOA response stated in item #10.
13. ns7 do the last query minimization name for the ip6.arpa. QNAME.
After all IPv6 labels are exausted the algorithm falls back to the
original QNAME:
test1.test2.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.9.0.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa
ns7 sends a new query with the original QNAME to ans4.
14. Finally ans4 answers with the expected response:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40969
;; flags: qr aa; QUESTION: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 8192
;; QUESTION SECTION:
;test1.test2.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.9.0.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. IN TXT
;; ANSWER SECTION:
;test1.test2.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.9.0.9.4.1.1.1.1.8.2.6.0.1.0.0.2.ip6.arpa. 1 IN TXT "long_ip6_name"
Before this commit, BIND was unable to resolve ip6.arpa names like
the one reported in issue #1847 when using query minimization.
As reported in the issue, an attempt to resolve a name like
'rec-test-dom-158937817846788.test123.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.3.4.3.5.4.0.8.2.6.0.1.0.0.2.ip6.arpa'
using default settings would fail.
The reason was that query minimization algorithm in 'fctx_minimize_qname'
would divide any ip6.arpa names in increasing number of labels,
7,11, ... up to 35, thus limiting the destination name (minimized) to a number
of 35 labels.
In case the last query minimization attempt (with 35 labels) would fail with
NXDOMAIN, BIND would attempt the query mininimization again with the exact
same QNAME, limited on the 35 labels, and that in turn would fail again.
This fix avoids this fail loop by considering the extra labels that may appear
in the leftmost part of an ip6.arpa name, those after the IPv6 part.
The test for assertion failure via large TCP packet needs to be repeated
multiple times (we use 300000). This commit fixes the input file to be
properly hexlified and uses the new packet.pl -r feature to send it
300000 times via TCP.
For some tests, we need to send big data streams (for TCP) or repeated
packets (for UDP), this commits adds `-r` option to packet.pl that sends
the same input <repeats> times using the specified protocol.
While
if (isc_refcount_decrement() == 1) { // memory_order_release
isc_refcount_destroy(); // memory_order_acquire
...
}
is theoretically the most efficent in practice, using
memory_order_acq_rel produces the same code on x86_64 and doesn't
trigger tsan data races (which use a idealistic model) if
isc_refcount_destroy() is not called immediately. In fact
isc_refcount_destroy() could be removed if we didn't want
to check for the count being 0 when isc_refcount_destroy() is
called.
https://stackoverflow.com/questions/49112732/memory-order-in-shared-pointer-destructor
In order to lower the amount of memory allocated at startup by named
instances used in the BIND system test suite, set the default value of
"max-cache-size" for these to 2 megabytes. The purpose of this change
is to prevent named instances (or even entire virtual machines) from
getting killed by the operating system on the test host due to excessive
memory use.
Remove all "max-cache-size" statements from named configuration files
used in system tests ("checkconf" notwithstanding) to prevent confusion
as the "-T maxcachesize=..." command line option takes precedence over
configuration files.
An implicit default of "max-cache-size 90%;" may cause memory use issues
on hosts which run numerous named instances in parallel (e.g. GitLab CI
runners) due to the cache RBT hash table now being pre-allocated [1] at
startup. Add a new command line option, "-T maxcachesize=...", to allow
the default value of "max-cache-size" to be overridden at runtime. When
this new option is in effect, it overrides any other "max-cache-size"
setting in the configuration, either implicit or explicit. This
approach was chosen because it is arguably the simplest one to
implement.
The following alternative approaches to solving this problem were
considered and ultimately rejected (after it was decided they were not
worth the extra code complexity):
- adding the same command line option, but making explicit
configuration statements have priority over it,
- adding a build-time option that allows the implicit default of
"max-cache-size 90%;" to be overridden.
[1] see commit e24bc324b4
Resolve "[CVE-2020-8623] A flaw in native PKCS#11 code can lead to a remotely triggerable assertion failure in pk11.c"
See merge request isc-projects/bind9!4037
It was discovered, that some systems might set EPROTO instead of EACCESS
on recvmsg() call causing spurious syslog messages from the socket
code. This commit returns soft handling of EPROTO errno code to the
socket code. [GL #1928]
When calculating the new hashtable bitsize, there was an off-by-one
error that would allow the new bitsize to be larger than maximum allowed
causing assertion failure in the rehash() function.
Printing test-suite.log on system test failure does not work for system
test run from tarball because the "after_script" step does not honour
directory change from the "before_script" step and fails with:
Running after script...
$ cat bin/tests/system/test-suite.log
cat: bin/tests/system/test-suite.log: No such file or directory
The rbtdb version glue_table has been refactored similarly to rbt.c hash
table, so it does use 32-bit hash function return values and apply
Fibonacci Hashing to lookup the index to the hash table instead of
modulo. For more details, see the lib/dns/rbt.c commit log.
The non-minimized corpus from https://github.com/CZ-NIC/dns-fuzzing was
used as input to afl-cmin, then every case were processed by afl-tmin
and then afl-cmin was used to further minimize the corpus again.
Previously, the bin/system/wire_test.c was optionally used as a fuzzer,
this commit extracts the parts relevant to the fuzzing into a
specialized fuzzer that can be used in oss-fuzz project.
The fuzzer parses the input as UDP DNS message, then prints parsed DNS
message, then renders the DNS message and then prints the rendered DNS
message. No part of the code should cause a assertion failure.
Shifting (signed) integer left could trigger undefined behaviour when
the shifted value would overflow into the sign bit (e.g. 2048).
The issue was found when using AFL++ and UBSAN:
message.c:2274:33: runtime error: left shift of 2048 by 20 places cannot be represented in type 'int'
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior message.c:2274:33 in
sockaddr.c:147:49: error: pointer targets in passing argument 2 of ‘isc__buffer_putmem’ differ in signedness
rdata.c:1780:30: error: pointer targets in passing argument 2 of ‘isc__buffer_putmem’ differ in signedness
When updating source files, we might forget to update pre-generated
files (generated by sphinx-build and cfg_gen) and then the extra changes
would get included in the random merge request.
This commit updates the tarball-create job to enable the maintainer
mode, then clean all maintainer files (`make maintainer-clean`) rebuild
all the file from scratch and compare the result which must be a clean
git directory.
This commit updates and simplifies the checks for the readline support
in nslookup and nsupdate:
* Change the autoconf checks to pkg-config only, all supported
libraries have accompanying .pc files now.
* Add editline support in addition to libedit and GNU readline
* Add isc/readline.h shim header that defines dummy readline()
function when no readline library is available
* Disallow compression pointers in names as we are not
reading from a packet and as a result length checks fail.
* Increase totext buffer size as fuzzer ran out of space on
big bitmaps.
* NUL terminate totext to make fault diagnosis easier.
* Add debugging messages to make fault diagnosie easier.
base32_decode_char() added a extra zero octet to the output
if the fifth character was a pad character. The length
of octets to copy to the output was set to 3 instead of 2.
Prevent intermittent false positives on slow platforms by subtracting
the number of seconds which passed between key creation and invoking
'rndc dnssec -checkds'.
This particularly fails for the step3.csk-roll2.autosign zone because
the closest next key event is when the zone signatures become
omnipresent. Running 'rndc dnssec -checkds' some time later means
that the next key event is in fact closer than the calculated time
and thus we need to adjust the expected time by the time already
passed.
The --enable-fuzzing option now allows third choice "ossfuzz" that just
adds $LIB_FUZZING_ENGINE to FUZZ_LDFLAGS to make the fuzzer builds
compatible with OSS-Fuzz project that has some special quirks (the
main() routine is provided in the static library the project provides).
Previously, we have disallowed static linking (for good reasons).
However, there are legitimate reasons where static linking might be
useful, and one of the reasons is the OSS-Fuzz project that doesn't have
the libraries used for build, so static linking is the sane option here.
The static linking is still disallowed in the "production" builds, but
it's not possible to disable shared and enable static libraries when
used together with --enable-developer.
There was a copy&paste error in fuzz/isc_lex_getmastertoken.c where we
didn't really test the function we wanted to test. Update the test to
have the input data to always include expected 'tokentype' in the first
byte, `eol` argument in the second byte and the rest of the input is the
data to parse.
Previously .txt files with full backtrace may be identified as a
crashed test:
I:Core dumps were found for the following system tests:
I: core.19948-backtrace.txt
I: shutdown
Now .txt files are removed from the list.
Change 'run.sh.in' to match the core matching pattern in
'testsummary.sh'.
Resolve "readline/rltypedefs.h:35:22: error: this function declaration is not a prototype on NetBSD 9"
Closes#2045
See merge request isc-projects/bind9!3926
Hold a weak reference to the view so that it can't go away while
nta is performing its lookups. Cancel nta timers once all external
references to the view have gone to prevent them triggering new work.
The hash table rework MRs (!3865, !3871) increased the default RBT hash
table size from 64 to 65,536 entries (for 64-bit architectures, that is
512 bytes before vs. 524,288 bytes after). This works fine for RBTs
used for cache databases, but since three separate RBT databases are
created for every zone loaded (RRs, NSEC, NSEC3), memory usage would
skyrocket when BIND 9 is used as an authoritative DNS server with many
zones.
The default RBT hash table size before the rework was 64 entries, this
commit reduces it to 16 entries because our educated guess is that most
zones are just couple of entries (SOA, NS, A, AAAA, MX) and rehashing
small hash tables is actually cheap. The rework we did in the previous
MRs tries to avoid growing the hash tables for big-to-huge caches where
growing the hash table comes at a price because the whole cache needs to
be locked.
(cherry picked from commit 1e043a011b)
The hash table rework MRs (!3865, !3871) increased the default RBT hash
table size from 64 to 65,536 entries (for 64-bit architectures, that is
512 bytes before vs. 524,288 bytes after). This works fine for RBTs
used for cache databases, but since three separate RBT databases are
created for every zone loaded (RRs, NSEC, NSEC3), memory usage would
skyrocket when BIND 9 is used as an authoritative DNS server with many
zones.
The default RBT hash table size before the rework was 64 entries, this
commit reduces it to 16 entries because our educated guess is that most
zones are just couple of entries (SOA, NS, A, AAAA, MX) and rehashing
small hash tables is actually cheap. The rework we did in the previous
MRs tries to avoid growing the hash tables for big-to-huge caches where
growing the hash table comes at a price because the whole cache needs to
be locked.
Running "make recheck" after the test suite fails hides intermittent
system test failures in GitLab CI. This makes it hard to identify which
branches are affected by a particular test failure mode and causes CI
results to be overly optimistic. Prevent "make recheck" from being run
when "make check" fails to ensure GitLab CI results properly reflect the
stability of the "main" branch.
Make sure the 'checkds' command correctly sets the right key timing
metadata and also make sure that it rejects setting the key timing
metadata if there are multiple keys with the KSK role and no key
identifier is provided.
With 'checkds' replacing 'parent-registration-delay', the kasp
test needs the expected times to be adjusted. Also the system test
needs to call 'rndc dnssec -checkds' to progress the rollovers.
Since we pretend that the KSK is active as soon as the DS is
submitted (and parent registration delay is no longer applicable)
we can simplify the 'csk_rollover_predecessor_keytimes' function
to take only one "addtime" parameter.
This commit also slightly changes the 'check_dnssecstatus' function,
passing the zone as a parameter.
Don't strip off the final character when printing times in key files.
With the introduction of 'rndc dnssec -status' we introduced
'isc_stdtime_tostring()'. This changed in behavior such that it was no
longer needed to strip of the final '\n' of the string format
datetime. However, in 'printtime()' it still stripped the final
character.
Add a new 'rndc' command 'dnssec -checkds' that allows the user to
signal named that a new DS record has been seen published in the
parent, or that an existing DS record has been withdrawn from the
parent.
Upon the 'checkds' request, 'named' will write out the new state for
the key, updating the 'DSPublish' or 'DSRemoved' timing metadata.
This replaces the "parent-registration-delay" configuration option,
this was unreliable because it was purely time based (if the user
did not actually submit the new DS to the parent for example, this
could result in an invalid DNSSEC state).
Because we cannot rely on the parent registration delay for state
transition, we need to replace it with a different guard. Instead,
if a key wants its DS state to be moved to RUMOURED, the "DSPublish"
time must be set and must not be in the future. If a key wants its
DS state to be moved to UNRETENTIVE, the "DSRemoved" time must be set
and must not be in the future.
By default, with '-checkds' you set the time that the DS has been
published or withdrawn to now, but you can set a different time with
'-when'. If there is only one KSK for the zone, that key has its
DS state moved to RUMOURED. If there are multiple keys for the zone,
specify the right key with '-key'.
When pk11_numbits() is passed a user provided input that contains all
zeroes (via crafted DNS message), it would crash with assertion
failure. Fix that by properly handling such input.
QNAME minimization is normally disabled when forwarding. if, in the
course of processing a fetch, we switch back to normal recursion at
some point, we can't safely start minimizing because we may have
been left in an inconsistent state.
Each worker has a receive buffer with space for 20 DNS messages of up
to 2^16 bytes each, and the allocator function passed to uv_read_start()
or uv_udp_recv_start() will reserve a portion of it for use by sockets.
UDP can use recvmmsg() and so it needs that entire space, but TCP reads
one message at a time.
This commit introduces separate allocator functions for TCP and UDP
setting different buffer size limits, so that libuv will provide the
correct buffer sizes to each of them.
The only arm64 runner we have at our disposal is suffering from
intermittent connectivity issues which make it unusable for extended
periods of time. Remove arm64 jobs from GitLab CI until we manage to
set up an arm64 runner with more reliable connectivity.
The named configuration files used in the "geoip2" system test cause a
rather large number of views (6-8) to be set up in each tested named
instance. Each view has its own cache.
Commit e24bc324b4 caused the RBT hash
table to be pre-allocated to a size derived from "max-cache-size", so
that it never needs to be rehashed. The size of that hash table is not
expected to be significant enough to cause memory use issues in typical
conditions even for large "max-cache-size" settings.
However, these two factors combined can cause memory exhaustion issues
in GitLab CI, where we run multiple "instances" of the test suite in
parallel on the same runner, each test suite executes multiple system
tests concurrently, and each system test may potentially start multiple
named instances at the same time. In practice, this problem currently
only seems to be affecting the "geoip2" system test, which is failing
intermittently due to named instances used by that test getting killed
by oom-killer.
Prevent the "geoip2" system test from failing intermittently by setting
"max-cache-size" in named configuration files used in that test to a low
value in order to keep memory usage at bay even with a large number of
views configured.
Resolve "BIND ARM incorrectly documents the processing of forwarders (still has the pre 9.3.0 explanation)"
Closes#2030
See merge request isc-projects/bind9!3881
Now that the log message has been printed set the result code to
DNS_R_FORMERR. We don't do this via dns_result_torcode() as we
don't want upstream errors to produce FORMERR if that processing
end with DNS_R_BADTSIG.
When a received RRSet has TTL 0, they would be preserved for
serve-stale (default `max-stale-cache` is 12 hours) rather than expiring
them quickly from the cache database.
This commit makes sure the RRSet didn't have TTL 0 before marking the
entry in the database as "stale".
The current serve-stale implementation in BIND 9 stores all received
records in the cache for a max-stale-ttl interval (default 12 hours).
This allows DNS operators to turn the serve-stale answers in an event of
large authoritative DNS outage. The caching of the stale answers needs
to be enabled before the outage happens or the feature would be
otherwise useless.
The negative consequence of the default setting is the inevitable
cache-bloat that happens for every and each DNS operator running named.
In this MR, a new configuration option `stale-cache-enable` is
introduced that allows the operators to selectively enable or disable
the serve-stale feature of BIND 9 based on their decision.
The newly introduced option has been disabled by default,
e.g. serve-stale is disabled in the default configuration and has to be
enabled if required.
In this commit, the simple fuzzing tests for the isc_lex_gettoken() and
isc_lex_getmastertoken() functions have been added.
As part of this commit, the initialization has been moved from fuzz.h
constructor/destructor to LLVMFuzzerInitialize() in each fuzz test. The
main.c of no-fuzzing and AFL modes have been modified to run the
LLVMFuzzerInitialize() at the start of the main() function mimicking
the libfuzzer mode of operation.
The fuzzing tests were temporarily disabled when the build system has been
converted to automake. This commit restores the functionality to run the
fuzzing tests as part of the `make check`. When the afl or libfuzzer
is enabled via ./configure, it uses a custom LOG_DRIVER (fuzz/<fuzzer.sh>).
Currently only libfuzzer.sh has been implemented that runs each fuzz
test for 5 seconds each.
When a new IPv6 interface/address appears it's first in a tentative
state - in which we cannot bind to it, yet it's already being reported
by the route socket. Because of that BIND9 is unable to listen on any
newly detected IPv6 addresses. Fix it by setting IP_FREEBIND option (or
equivalent option on other OSes) and then retrying bind() call.
Created isc_refcount_decrement_expect macro to test conditionally
the return value to ensure it is in expected range. Converted
unchecked isc_refcount_decrement to use isc_refcount_decrement_expect.
Converted INSIST(isc_refcount_decrement()...) to isc_refcount_decrement_expect.
When silencing the Coverity warning in remove_old_tsversions(), the code
was refactored to reduce the indentation levels and break down the long
code into individual functions. This improve fix for [GL #1989].
':!.gitlab-ci.yml' is a pathspec pattern used to limit paths in the "git
grep" command to all but the .gitlab-ci.yml file which includes the
checked word itself. This requires Git 2.13.
It seems that config.guess gets always created in source root, so for
that sake of out-of-tree system test, we should expect the file there
instead of where configure was run.
The $SYSTEMTESTTOP shell variable if often set to .. in various shell
scripts inside bin/tests/system/, but most of the time it is only
used one line later, while sourcing conf.sh. This hardly improves
code readability.
$SYSTEMTESTTOP is also used for the purpose of referencing
scripts/files living in bin/tests/system/, but given that the
variable is always set to a short, relative path, we can drop it and
replace all of its occurrences with the relative path without adversely
affecting code readability.
When named acting as a resolver connects to an authoritative server over
TCP, it sets the idle timeout for that connection to 20 seconds. This
fixed timeout was picked back when the default processing timeout for
each client query was hardcoded to 30 seconds. Commit
000a8970f8 made this processing timeout
configurable through "resolver-query-timeout" and decreased its default
value to 10 seconds, but the idle TCP timeout was not adjusted to
reflect that change. As a result, with the current defaults in effect,
a single hung TCP connection will consistently cause the resolution
process for a given query to time out.
Set the idle timeout for connected TCP sockets to half of the client
query processing timeout configured for a resolver. This allows named
to handle hung TCP connections more robustly and prevents the timeout
mismatch issue from resurfacing in the future if the default is ever
changed again.
when building without ISC_BUFFER_USEINLINE (which is the default on
Windows) an assertion failure could occur when setting up a new
isc_httpd_t object for the statistics channel.
Whenever an exact match is found by dns_rbt_findnode(),
the highest level node in the chain will not be put into
chain->levels[] array, but instead the chain->end
pointer will be adjusted to point to that node.
Suppose we have the following entries in a rpz zone:
example.com CNAME rpz-passthru.
*.example.com CNAME rpz-passthru.
A query for www.example.com would result in the
following chain object returned by dns_rbt_findnode():
chain->level_count = 2
chain->level_matches = 2
chain->levels[0] = .
chain->levels[1] = example.com
chain->levels[2] = NULL
chain->end = www
Since exact matches only care for testing rpz set bits,
we need to test for rpz wild bits through iterating the nodechain, and
that includes testing the rpz wild bits in the highest level node found.
In the case of an exact match, chain->levels[chain->level_matches]
will be NULL, to address that we must use chain->end as the start point,
then iterate over the remaining levels in the chain.
Creation of EVP_MD_CTX and EVP_PKEY is quite expensive, so until we fix the code
to reuse the OpenSSL contexts and keys we'll use our own implementation of
siphash instead of trying to integrate with OpenSSL.
There were several problems with rbt hashtable implementation:
1. Our internal hashing function returns uint64_t value, but it was
silently truncated to unsigned int in dns_name_hash() and
dns_name_fullhash() functions. As the SipHash 2-4 higher bits are
more random, we need to use the upper half of the return value.
2. The hashtable implementation in rbt.c was using modulo to pick the
slot number for the hash table. This has several problems because
modulo is: a) slow, b) oblivious to patterns in the input data. This
could lead to very uneven distribution of the hashed data in the
hashtable. Combined with the single-linked lists we use, it could
really hog-down the lookup and removal of the nodes from the rbt
tree[a]. The Fibonacci Hashing is much better fit for the hashtable
function here. For longer description, read "Fibonacci Hashing: The
Optimization that the World Forgot"[b] or just look at the Linux
kernel. Also this will make Diego very happy :).
3. The hashtable would rehash every time the number of nodes in the rbt
tree would exceed 3 * (hashtable size). The overcommit will make the
uneven distribution in the hashtable even worse, but the main problem
lies in the rehashing - every time the database grows beyond the
limit, each subsequent rehashing will be much slower. The mitigation
here is letting the rbt know how big the cache can grown and
pre-allocate the hashtable to be big enough to actually never need to
rehash. This will consume more memory at the start, but since the
size of the hashtable is capped to `1 << 32` (e.g. 4 mio entries), it
will only consume maximum of 32GB of memory for hashtable in the
worst case (and max-cache-size would need to be set to more than
4TB). Calling the dns_db_adjusthashsize() will also cap the maximum
size of the hashtable to the pre-computed number of bits, so it won't
try to consume more gigabytes of memory than available for the
database.
FIXME: What is the average size of the rbt node that gets hashed? I
chose the pagesize (4k) as initial value to precompute the size of
the hashtable, but the value is based on feeling and not any real
data.
For future work, there are more places where we use result of the hash
value modulo some small number and that would benefit from Fibonacci
Hashing to get better distribution.
Notes:
a. A doubly linked list should be used here to speedup the removal of
the entries from the hashtable.
b. https://probablydance.com/2018/06/16/fibonacci-hashing-the-optimization-that-the-world-forgot-or-a-better-alternative-to-integer-modulo/
Make sure bin/tests/system/run.sh returns a non-zero exit code if any of
the following happens:
- the test being run produces a core dump,
- assertion failures are found in the test's logs,
- ThreadSanitizer reports are found after the test completes,
- the servers started by the test fail to shut down cleanly.
This change is necessary to always fail a test in such cases (before the
migration to Automake, test failures were determined based on the
presence of "R:<test-name>:FAIL" lines in the test suite output and thus
it was not necessary for bin/tests/system/run.sh to return a non-zero
exit code).
Add an item to the release checklist to make sure confidential issues
assigned to the relevant milestone are made public after the BIND
versions addressing them are released.
Fix Coverity CHECKED_RETURN reports for dst_key_getbool(). In most
cases we do not really care about its return value, but it is prudent
to check it.
In one case, where a dst_key_getbool() error should be treated
identically as success, cast the return value to void and add a relevant
comment.
Our GitLab Runner Custom executor scripts now use the "image" key
instead of the job name for determining the QCOW2 image to use for a
given CI job. Update .gitlab-ci.yml to reflect that change.
Since October 2019 I have had complaints from `dnssec-cds` reporting
that the signatures on some of my test zones had expired. These were
zones signed by BIND 9.15 or 9.17, with a DNSKEY TTL of 24h and
`sig-validity-interval 10 8`.
This is the same setup we have used for our production zones since
2015, which is intended to re-sign the zones every 2 days, keeping
at least 8 days signature validity. The SOA expire interval is 7
days, so even in the presence of zone transfer problems, no-one
should ever see expired signatures. (These timers are a bit too
tight to be completely correct, because I should have increased
the expiry timers when I increased the DNSKEY TTLs from 1h to 24h.
But that should only matter when zone transfers are broken, which
was not the case for the error reports that led to this patch.)
For example, this morning my test zone contained:
dev.dns.cam.ac.uk. 86400 IN RRSIG DNSKEY 13 5 86400 (
20200701221418 20200621213022 ...)
But one of my resolvers had cached:
dev.dns.cam.ac.uk. 21424 IN RRSIG DNSKEY 13 5 86400 (
20200622063022 20200612061136 ...)
This TTL was captured at 20200622105807 so the resolver cached the
RRset 64976 seconds previously (18h02m56s), at 20200621165511
only about 12h before expiry.
The other symptom of this error was incorrect `resign` times in
the output from `rndc zonestatus`.
For example, I have configured a test zone
zone fast.dotat.at {
file "../u/z/fast.dotat.at";
type primary;
auto-dnssec maintain;
sig-validity-interval 500 499;
};
The zone is reset to a minimal zone containing only SOA and NS
records, and when `named` starts it loads and signs the zone. After
that, `rndc zonestatus` reports:
next resign node: fast.dotat.at/NS
next resign time: Fri, 28 May 2021 12:48:47 GMT
The resign time should be within the next 24h, but instead it is
near the signature expiry time, which the RRSIG(NS) says is
20210618074847. (Note 499 hours is a bit more than 20 days.)
May/June 2021 is less than 500 days from now because expiry time
jitter is applied to the NS records.
Using this test I bisected this bug to 09990672d which contained a
mistake leading to the resigning interval always being calculated in
hours, when days are expected.
This bug only occurs for configurations that use the two-argument form
of `sig-validity-interval`.
Resolve "gssapictx.c:681:10: error: implicit declaration of function 'gsskrb5_register_acceptor_identity' on illumos"
Closes#1995
See merge request isc-projects/bind9!3830
When we're shutting the system down via "rndc stop" or "rndc halt",
or reconfiguring the control channel, there are potential shutdown
races between the server task and network manager. These are adressed by:
- purging any pending command tasks when shutting down the control channel
- adding an extra handle reference before the command handler to
ensure the handle can't be deleted out from under us before calling
command_respond()
- using an isc_task to execute all rndc functions makes it relatively
simple for them to acquire task exclusive mode when needed
- control_recvmessage() has been separated into two functions,
control_recvmessage() and control_respond(). the respond function
can be called immediately from control_recvmessage() when processing
a nonce, or it can be called after returning from the task event
that ran the rndc command function.
- updated libisccc to use netmgr events
- updated rndc to use isc_nm_tcpconnect() to establish connections
- updated control channel to use isc_nm_listentcp()
open issues:
- the control channel timeout was previously 60 seconds, but it is now
overridden by the TCP idle timeout setting, which defaults to 30
seconds. we should add a function that sets the timeout value for
a specific listener socket, instead of always using the global value
set in the netmgr. (for the moment, since 30 seconds is a reasonable
timeout for the control channel, I'm not prioritizing this.)
- the netmgr currently has no support for UNIX-domain sockets; until
this is addressed, it will not be possible to configure rndc to use
them. we will need to either fix this or document the change in
behavior.
The basic scenario for the problem was that in the process of
resolving a query, if any rrset was eligible for prefetching, then it
would trigger a call to query_prefetch(), this call would run in
parallel to the normal query processing.
The problem arises due to the fact that both query_prefetch(), and,
in the original thread, a call to ns_query_recurse(), try to attach
to the recursionquota, but recursing client stats counter is only
incremented if ns_query_recurse() attachs to it first.
Conversely, if fetch_callback() is called before prefetch_done(),
it would not only detach from recursionquota, but also decrement
the stats counter, if query_prefetch() attached to te quota first
that would result in a decrement not matched by an increment, as
expected.
To solve this issue an atomic bool was added, it is set once in
ns_query_recurse(), allowing fetch_callback() to check for it
and decrement stats accordingly.
For a more compreensive explanation check the thread comment below:
https://gitlab.isc.org/isc-projects/bind9/-/issues/1719#note_145857
If too many versions of log / dnstap files to be saved where requests
the memory after to_keep could be overwritten. Force the number of
versions to be saved to a save level. Additionally the memmove length
was incorrect.
When "rndc reconfig" is run, named first configures a fresh set of views
and then tears down the old views. Consider what happens for a single
view with LMDB enabled; "envA" is the pointer to the LMDB environment
used by the original/old version of the view, "envB" is the pointer to
the same LMDB environment used by the new version of that view:
1. mdb_env_open(envA) is called when the view is first created.
2. "rndc reconfig" is called.
3. mdb_env_open(envB) is called for the new instance of the view.
4. mdb_env_close(envA) is called for the old instance of the view.
This seems to have worked so far. However, an upstream change [1] in
LMDB which will be part of its 0.9.26 release prevents the above
sequence of calls from working as intended because the locktable mutexes
will now get destroyed by the mdb_env_close() call in step 4 above,
causing any subsequent mdb_txn_begin() calls to fail (because all of the
above steps are happening within a single named process).
Preventing the above scenario from happening would require either
redesigning the way we use LMDB in BIND, which is not something we can
easily backport, or redesigning the way BIND carries out its
reconfiguration process, which would be an even more severe change.
To work around the problem, set MDB_NOLOCK when calling mdb_env_open()
to stop LMDB from controlling concurrent access to the database and do
the necessary locking in named instead. Reuse the view->new_zone_lock
mutex for this purpose to prevent the need for modifying struct dns_view
(which would necessitate library API version bumps). Drop use of
MDB_NOTLS as it is made redundant by MDB_NOLOCK: MDB_NOTLS only affects
where LMDB reader locktable slots are stored while MDB_NOLOCK prevents
the reader locktable from being used altogether.
[1] https://git.openldap.org/openldap/openldap/-/commit/2fd44e325195ae81664eb5dc36e7d265927c5ebc
2020-07-10 11:29:18 +02:00
2056 changed files with 12031 additions and 7614 deletions
- [ ]***(Support)*** Publish links to downloads on ISC website.
- [ ]***(Support)*** Write release email to *bind-announce*.
- [ ]***(Support)*** Write email to *bind-users* (if a major release).
- [ ]***(Support)*** Send eligible customers updated links to the Subscription Edition.
- [ ]***(Support)*** Update tickets in case of waiting support customers.
- [ ]***(QA)*** Build and test any outstanding private packages.
- [ ]***(QA)*** Build public packages (`*.deb`, RPMs).
@@ -67,6 +68,7 @@
- [ ]***(SwEng)*** Push tags for the published releases to the public repository.
- [ ]***(QA)*** For each maintained branch, update the `BIND_BASELINE_VERSION` variable for the `abi-check` job in `.gitlab-ci.yml` to the latest published BIND version tag for a given branch.
- [ ]***(QA)*** Prepare empty release notes for the next set of releases.
- [ ]***(QA)*** Sanitize all confidential issues assigned to the release milestone and make them public.
- [ ]***(QA)*** Update QA tools used in GitLab CI (e.g. Flake8, PyLint) by modifying the relevant `Dockerfile`.
[^1]: If not, use the time remaining until the tagging deadline to ensure all outstanding issues are either resolved or moved to a different milestone.
@@ -46,8 +46,9 @@ building communities that are welcoming and inclusive: environments where people
are encouraged to share ideas, treat each other with respect, and collaborate
towards the best solutions. To reinforce our commitment, ISC
has adopted a slightly modified version of the Django
[Code of Conduct](https://gitlab.isc.org/isc-projects/bind9/-/blob/master/CODE_OF_CONDUCT.md) for the BIND 9 project, as well as for the conduct of our
developers throughout the industry.
[Code of Conduct](https://gitlab.isc.org/isc-projects/bind9/-/blob/main/CODE_OF_CONDUCT.md)
for the BIND 9 project, as well as for the conduct of our developers throughout
the industry.
### <a name="access"></a>Access to source code
@@ -80,7 +81,7 @@ Whenever a branch is ready for publication, a tag is placed of the
form `v9_X_Y`. The 9.12.0 release, for instance, is tagged as `v9_12_0`.
The branch in which the next major release is being developed is called
`master`.
`main`.
### <a name="bugs"></a>Reporting bugs
@@ -100,6 +101,7 @@ use credentials from an existing account at GitHub, GitLab, Google,
Twitter, or Facebook.
### Reporting possible security issues
If you think you may be seeing a potential security vulnerability in BIND
(for example, a crash with REQUIRE, INSIST, or ASSERT failure), please
report it immediately by emailing to security-officer@isc.org. Plain-text
@@ -111,7 +113,8 @@ Do not discuss undisclosed security vulnerabilities on any public mailing list.
ISC has a long history of handling reported vulnerabilities promptly and
effectively and we respect and acknowledge responsible reporters.
ISC's Security Vulnerability Disclosure Policy is documented at [https://kb.isc.org/docs/aa-00861](https://kb.isc.org/docs/aa-00861).
ISC's Security Vulnerability Disclosure Policy is documented at
or, if you have Xcode already installed, you can run
`xcode-select--install`. (Note that an Apple ID may be required to access the download
page.)
or, if you have Xcode already installed, you can run`xcode-select --install`.
(Note that an Apple ID may be required to access the download page.)
#### <a name="dependencies"> Dependencies
@@ -208,9 +207,6 @@ installed:
To see a full list of configuration options, run `configure --help`.
To build shared libraries, specify `--with-libtool` on the `configure`
command line.
For the server to support DNSSEC, you need to build it with crypto support.
To use OpenSSL, you should have OpenSSL 1.0.2e or newer installed. If the
OpenSSL library is installed in a nonstandard location, specify the prefix
@@ -339,7 +335,7 @@ the change that was made; these categories are:
| [cleanup] | Minor corrections and refactoring |
| [doc] | Documentation |
| [contrib] | Changes to the contributed tools and libraries in the 'contrib' subdirectory |
| [placeholder] | Used in the master development branch to reserve change numbers for use in other branches, e.g., when fixing a bug that only exists in older releases |
| [placeholder] | Used in the main development branch to reserve change numbers for use in other branches, e.g., when fixing a bug that only exists in older releases |
In general, [func] and [experimental] tags only appear in new-feature
releases (i.e., those with version numbers ending in zero). Some new
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