The pthread_self(), thrd_current() or GetCurrentThreadId() could
actually be a pointer, so we should rather convert the value into
uintptr_t instead of unsigned long.
Convert the isc_hp API to use the globally available isc_tid_v instead
of locally defined tid_v. This should solve most of the problems on
machines with many number of cores / CPUs.
The current isc_hp API uses internal tid_v variable that gets
incremented for each new thread using hazard pointers. This tid_v
variable is then used as a index to global shared table with hazard
pointers state. Since the tid_v is only incremented and never
decremented the table could overflow very quickly if we create set of
threads for short period of time, they finish the work and cease to
exist. Then we create identical set of threads and so on and so on.
This is not a problem for a normal `named` operation as the set of
threads is stable, but the problematic place are the unit tests where we
test network manager or other APIs (task, timer) that create threads.
This commits adds a thin wrapper around any function called from
isc_thread_create() that adds unique-but-reusable small digit thread id
that can be used as index to f.e. hazard pointer tables. The trampoline
wrapper ensures that the thread ids will be reused, so the highest
thread_id number doesn't grow indefinitely when threads are created and
destroyed and then created again. This fixes the hazard pointer table
overflow on machines with many cores. [GL #2396]
When a staleonly lookup doesn't find a satisfying answer, it should
not try to respond to the client.
This is not true when the initial lookup is staleonly (that is when
'stale-answer-client-timeout' is set to 0), because no resolver fetch
has been created at this point. In this case continue with the lookup
normally.
Fix a crash that can happen in the following scenario:
A client request is received. There is no data for it in the cache,
(not even stale data). A resolver fetch is created as part of
recursion.
Some time later, the fetch still hasn't completed, and
stale-answer-client-timeout is triggered. A staleonly lookup is
started. It will also find no data in the cache.
So 'query_lookup()' will call 'query_gotanswer()' with ISC_R_NOTFOUND,
so this will call 'query_notfound()' and this will start recursion.
We will eventually end up in 'ns_query_recurse()' and that requires
the client query fetch to be NULL:
REQUIRE(client->query.fetch == NULL);
If the previously started fetch is still running this assertion
fails.
The crash is easily prevented by not requiring recursion for
staleonly lookups.
Also remove a redundant setting of the staleonly flag at the end of
'query_lookup_staleonly()' before destroying the query context.
Add a system test to catch this case.
When applying dnssec-policy on a dynamic zone (e.g. that allows Dynamic
Updates), the NSEC3 parameters were put on the queue, but they were
not being processed (until a reload of the zone or reconfiguration).
Process the NSEC3PARAM queue on zone postload when handling a
dynamic zone.
The BIND 9 libraries on Windows define DllMain() optional entry point
into a dynamic-link library (DLL). When the system starts or terminates
a process or thread, it calls the entry-point function for each loaded
DLL using the first thread of the process.
When the DLL is being loaded into the virtual address space of the
current process as a result of the process starting up, we make a call
to DisableThreadLibraryCalls() which should disable the
DLL_THREAD_ATTACH and DLL_THREAD_DETACH notifications for the specified
dynamic-link library (DLL).
This seems not be the case because we never check the return value of
the DisableThreadLibraryCalls() call, and it could in fact fail. The
DisableThreadLibraryCalls() function fails if the DLL specified by
hModule has active static thread local storage, or if hModule is an
invalid module handle.
In this commit, we remove the safe-guard assertion put in place for the
DLL_THREAD_ATTACH and DLL_THREAD_DETACH events and we just ignore them.
BIND 9 doesn't create/destroy enough threads for it actually to make any
difference, and in fact we do use static thread local storage in the
code.
The 'checknames' field wasn't initialized in dns_view_create(), but it
should otherwise AddressSanitizer identifies the following runtime error
in query_test.c.
runtime error: load of value 190, which is not a valid value for type '_Bool'
'checknames' field of struct dns_view is not initialized by
dns_view_create(). ASAN identified this as runtime error:
runtime error: load of value 190, which is not a valid value for type '_Bool'
Removing stderr from the pict tool serves no purpose and drops valuable
information, we might use when debugging failed pairwise CI job, such
as:
Input Error: A parameter names must be unique
*** CID 320481: Null pointer dereferences (REVERSE_INULL)
/bin/tests/wire_test.c: 261 in main()
255 process_message(input);
256 }
257 } else {
258 process_message(input);
259 }
260
CID 320481: Null pointer dereferences (REVERSE_INULL)
Null-checking "input" suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
261 if (input != NULL) {
262 isc_buffer_free(&input);
263 }
264
265 if (printmemstats) {
266 isc_mem_stats(mctx, stdout);
remove redundant 'inst != NULL' test
162cleanup:
CID 281450 (#1 of 1): Dereference before null check (REVERSE_INULL)
check_after_deref: Null-checking inst suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
163 if (result != ISC_R_SUCCESS && inst != NULL) {
164 plugin_destroy((void **)&inst);
165 }
Removed redundant 'listener != NULL' check.
1191cleanup:
CID 304936 (#1 of 1): Dereference before null check (REVERSE_INULL)
check_after_deref: Null-checking listener suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
1192 if (listener != NULL) {
1193 isc_refcount_decrement(&listener->refs);
1194 listener->exiting = true;
1195 free_listener(listener);
1196 }
Two minor fixes in the kasp system test:
1. A wrong comment in ns3/setup.sh (we are subtracting 2 hours, not
adding them).
2. 'get_keyids' used bad parameters "$1" "$2" when 'check_numkeys'
failed. Also, 'check_numkeys' can use $DIR, $ZONE, and $NUMKEYS
directly, no need to pass them.
Add some more zones to the kasp system test to test the 'purge-keys'
option. Three zones test that the predecessor key files are removed
after the purge keys interval, one test checks that the key files
are retained if 'purge-keys' is disabled. For that, we change the
times to 90 days in the past (the default value for 'purge-keys').
On each keymgr run, we now also check if key files can be removed.
The 'purge-keys' interval determines how long keys should be retained
after they have become completely hidden.
Key files should not be removed if it has a state that is set to
something else then HIDDEN, if purge-keys is 0 (disabled), if
the key goal is set to OMNIPRESENT, or if the key is unused (a key is
unused if no timing metadata set, and no states are set or if set,
they are set to HIDDEN).
If the last changed timing metadata plus the purge-keys interval is
in the past, the key files may be removed.
Add a dst_key_t variable 'purge' to signal that the key file should
not be written to file again.
Add a new option 'purge-keys' to 'dnssec-policy' that will purge key
files for deleted keys. The option determines how long key files
should be retained prior to removing the corresponding files from
disk.
If set to 0, the option is disabled and 'named' will not remove key
files from disk.
dns_dt_open() is not currently called with mode dns_dtmode_unix.
*** CID 281489: Resource leaks (RESOURCE_LEAK)
/lib/dns/dnstap.c: 983 in dns_dt_open()
977
978 if (!dnstap_file(handle->reader)) {
979 CHECK(DNS_R_BADDNSTAP);
980 }
981 break;
982 case dns_dtmode_unix:
CID 281489: Resource leaks (RESOURCE_LEAK)
Variable "handle" going out of scope leaks the storage it points to.
983 return (ISC_R_NOTIMPLEMENTED);
984 default:
985 INSIST(0);
986 ISC_UNREACHABLE();
987 }
988
The addition of lib/isc/tls_p.h to the source tree was not accounted for
in the relevant variable in lib/isc/Makefile.am and thus the former file
is not being included in release tarballs prepared using "make dist".
Fix by tweaking the libisc_la_SOURCES list in lib/isc/Makefile.am
accordingly.
The build-time requirement for libtool was introduced inadvertently:
1. Commit 1628f5865acb2d472ce4adf71fc78ac99094fa1c added a check to
configure.ac which claims to test whether the libtool script is
available. There are two problems with that check:
- it is effectively a no-op as the AC_PROG_LIBTOOL() macro always
sets the LIBTOOL variable [1],
- this check was intended to be performed before autoreconf is
run, not when ./configure is run; the libtool script is supposed
to be dynamically generated by ./configure on the build host and
thus there is no need for a standalone libtool script to be
installed system-wide on every host attempting to build BIND 9
e.g. from a tarball produced by "make dist".
2. Commit a7982d14dddb864420deb49e735f782022d1fa07 was based on the
incorrect assumption that the AC_PROG_LIBTOOL() macro looks for the
libtool binary in PATH and sets the LIBTOOL variable accordingly,
which is what other AC_PROG_*() macros do. Meanwhile, the
AC_PROG_LIBTOOL() macro only initializes libtool for use with
Automake. It is not necessary for a standalone libtool script to be
available in PATH on the build host when ./configure is run.
Do not look for libtool in PATH at build time as it prevents hosts
without a libtool script available system-wide from building BIND 9 from
source tarballs prepared using "make dist". Note that libtool m4
macros, utilities, etc. still need to be present on a given host if
autoreconf is to be run on it.
[1] https://git.savannah.gnu.org/cgit/libtool.git/tree/m4/libtool.m4?h=v2.4.6#n89
