when built without libtool, the sample driver in the dyndb
system test runs library intializers that have already been
run, causing the value for isc__trampoline_min to be reset.
wrap the trampoline initialize and shutdown routines under
isc_once_do() to ensure that they are only run once.
When attaching to the trampoline, the isc__trampoline_max was access
unlocked. This would not manifest under normal circumstances because we
initialize 65 trampolines by default and that's enough for most
commodity hardware, but there are ARM machines with 128+ cores where
this would be reported by ThreadSanitizer.
Add locking around the code in isc__trampoline_attach(). This also
requires the lock to leak on exit (along with memory that we already)
because a new thread might be attaching to the trampoline while we are
running the library destructor at the same time.
(cherry picked from commit 933162ae14)
When we compile with libuv that has some capabilities via flags passed
to f.e. uv_udp_listen() or uv_udp_bind(), the call with such flags would
fail with invalid arguments when older libuv version is linked at the
runtime that doesn't understand the flag that was available at the
compile time.
Enforce minimal libuv version when flags have been available at the
compile time, but are not available at the runtime. This check is less
strict than enforcing the runtime libuv version to be same or higher
than compile time libuv version.
Since version 5.0.0, decay-based purging is the only available dirty
page cleanup mechanism in jemalloc. It relies on so-called tickers,
which are simple data structures used for ensuring that certain actions
are taken "once every N times". Ticker data (state) is stored in a
thread-specific data structure called tsd in jemalloc parlance. Ticks
are triggered when extents are allocated and deallocated. Once every
1000 ticks, jemalloc attempts to release some of the dirty pages hanging
around (if any). This allows memory use to be kept in check over time.
This dirty page cleanup mechanism has a quirk. If the first
allocator-related action for a given thread is a free(), a
minimally-initialized tsd is set up which does not include ticker data.
When that thread subsequently calls *alloc(), the tsd transitions to its
nominal state, but due to a certain flag being set during minimal tsd
initialization, ticker data remains unallocated. This prevents
decay-based dirty page purging from working, effectively enabling memory
exhaustion over time. [1]
The quirk described above has been addressed (by moving ticker state to
a different structure) in jemalloc's development branch [2], but not in
any numbered jemalloc version released to date (the latest one being
5.2.1 as of this writing).
Work around the problem by ensuring that every thread spawned by
isc_thread_create() starts with a malloc() call. Avoid immediately
calling free() for the dummy allocation to prevent an optimizing
compiler from stripping away the malloc() + free() pair altogether.
An alternative implementation of this workaround was considered that
used a pair of isc_mem_create() + isc_mem_destroy() calls instead of
malloc() + free(), enabling the change to be fully contained within
isc__trampoline_run() (i.e. to not touch struct isc__trampoline), as the
compiler is not allowed to strip away arbitrary function calls.
However, that solution was eventually dismissed as it triggered
ThreadSanitizer reports when tools like dig, nsupdate, or rndc exited
abruptly without waiting for all worker threads to finish their work.
[1] https://github.com/jemalloc/jemalloc/issues/2251
[2] c259323ab3
(cherry picked from commit 7aa7b6474b)
When backporting the load balanced sockets to BIND 9.16, the Windows
specific paths were missed. Add the #if(n)def _WIN32 back into the
appropriate places.
Previously, HAVE_SO_REUSEPORT_LB has been defined only in the private
netmgr-int.h header file, making the configuration of load balanced
sockets inoperable.
Move the missing HAVE_SO_REUSEPORT_LB define the isc/netmgr.h and add
missing isc_nm_getloadbalancesockets() implementation.
(cherry picked from commit 142c63dda8)
Previously, the option to enable kernel load balancing of the sockets
was always enabled when supported by the operating system (SO_REUSEPORT
on Linux and SO_REUSEPORT_LB on FreeBSD).
It was reported that in scenarios where the networking threads are also
responsible for processing long-running tasks (like RPZ processing, CATZ
processing or large zone transfers), this could lead to intermitten
brownouts for some clients, because the thread assigned by the operating
system might be busy. In such scenarious, the overall performance would
be better served by threads competing over the sockets because the idle
threads can pick up the incoming traffic.
Add new configuration option (`load-balance-sockets`) to allow enabling
or disabling the load balancing of the sockets.
(cherry picked from commit 85c6e797aa)
In couple places, we have missed INSIST(0) or ISC_UNREACHABLE()
replacement on some branches with UNREACHABLE(). Replace all
ISC_UNREACHABLE() or INSIST(0) calls with UNREACHABLE().
The backport of using modern compiler features broken Windows debug
build because there's no __builtin_unreachable() in MSVC.
Define __builtin_unreachable() shim on MSVC using __assume(0).
Historically, the inline keyword was a strong suggestion to the compiler
that it should inline the function marked inline. As compilers became
better at optimising, this functionality has receded, and using inline
as a suggestion to inline a function is obsolete. The compiler will
happily ignore it and inline something else entirely if it finds that's
a better optimisation.
Therefore, remove all the occurences of the inline keyword with static
functions inside single compilation unit and leave the decision whether
to inline a function or not entirely on the compiler
NOTE: We keep the usage the inline keyword when the purpose is to change
the linkage behaviour.
(cherry picked from commit 20f0936cf2)
Previously, the unreachable code paths would have to be tagged with:
INSIST(0);
ISC_UNREACHABLE();
There was also older parts of the code that used comment annotation:
/* NOTREACHED */
Unify the handling of unreachable code paths to just use:
UNREACHABLE();
The UNREACHABLE() macro now asserts when reached and also uses
__builtin_unreachable(); when such builtin is available in the compiler.
(cherry picked from commit 584f0d7a7e)
Gcc 7+ and Clang 10+ have implemented __attribute__((fallthrough)) which
is explicit version of the /* FALLTHROUGH */ comment we are currently
using.
Add and apply FALLTHROUGH macro that uses the attribute if available,
but does nothing on older compilers.
In one case (lib/dns/zone.c), using the macro revealed that we were
using the /* FALLTHROUGH */ comment in wrong place, remove that comment.
(cherry picked from commit fe7ce629f4)
Upcoming LLVM/Clang 15 has marked the ATOMIC_VAR_INIT() as deprecated
breaking the build. In the previous commit, we have removed the use of
ATOMIC_VAR_INIT(), but as that was a prerequisite to using the
--enable-mutexatomic debugging mode, we have to remove the debugging
mode.
The C17 standard deprecated ATOMIC_VAR_INIT() macro (see [1]). Follow
the suite and remove the ATOMIC_VAR_INIT() usage in favor of simple
assignment of the value as this is what all supported stdatomic.h
implementations do anyway:
* MacOSX.plaform: #define ATOMIC_VAR_INIT(__v) {__v}
* Gcc stdatomic.h: #define ATOMIC_VAR_INIT(VALUE) (VALUE)
1. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1138r0.pdf
(cherry picked from commit f251d69eba)
The clang-format-15 has new option InsertBraces that could add missing
branches around single line statements. Use that to our advantage
without switching to not-yet-released LLVM version to add missing braces
in couple of places.
Previously, the established TCP connections (both client and server)
would be gracefully closed waiting for the write timeout.
Don't wait for TCP connections to gracefully shutdown, but directly
reset them for faster shutdown.
(cherry picked from commit 6ddac2d56d)
Previously, there was a single per-socket write timer that would get
restarted for every new write. This turned out to be insufficient
because the other side could keep reseting the timer, and never reading
back the responses.
Change the single write timer to per-send timer which would in turn
reset the TCP connection on the first send timeout.
(cherry picked from commit a761aa59e3)
When sock->closehandle_cb is set, we need to run nmhandle_detach_cb()
asynchronously to ensure correct order of multiple packets processing in
the isc__nm_process_sock_buffer(). When not run asynchronously, it
would cause:
a) out-of-order processing of the return codes from processbuffer();
b) stack growth because the next TCP DNS message read callback will
be called from within the current TCP DNS message read callback.
The sock->closehandle_cb is set to isc__nm_resume_processing() for TCP
sockets which calls isc__nm_process_sock_buffer(). If the read callback
(called from isc__nm_process_sock_buffer()->processbuffer()) doesn't
attach to the nmhandle (f.e. because it wants to drop the processing or
we send the response directly via uv_try_write()), the
isc__nm_resume_processing() (via .closehandle_cb) would call
isc__nm_process_sock_buffer() recursively.
The below shortened code path shows how the stack can grow:
1: ns__client_request(handle, ...);
2: isc_nm_tcpdns_sequential(handle);
3: ns_query_start(client, handle);
4: query_lookup(qctx);
5: query_send(qctcx->client);
6: isc__nmhandle_detach(&client->reqhandle);
7: nmhandle_detach_cb(&handle);
8: sock->closehandle_cb(sock); // isc__nm_resume_processing
9: isc__nm_process_sock_buffer(sock);
10: processbuffer(sock); // isc__nm_tcpdns_processbuffer
11: isc_nmhandle_attach(req->handle, &handle);
12: isc__nm_readcb(sock, req, ISC_R_SUCCESS);
13: isc__nm_async_readcb(NULL, ...);
14: uvreq->cb.recv(...); // ns__client_request
Instead, if 'sock->closehandle_cb' is set, we need to run detach the
handle asynchroniously in 'isc__nmhandle_detach', so that on line 8 in
the code flow above does not start this recursion. This ensures the
correct order when processing multiple packets in the function
'isc__nm_process_sock_buffer()' and prevents the stack growth.
When not run asynchronously, the out-of-order processing leaves the
first TCP socket open until all requests on the stream have been
processed.
If the pipelining is disabled on the TCP via `keep-response-order`
configuration option, named would keep the first socket in lingering
CLOSE_WAIT state when the client sends an incomplete packet and then
closes the connection from the client side.
Previously, the function(s) in the commit subject could fail for various
reasons - mostly allocation failures, or other functions returning
different return code than ISC_R_SUCCESS. Now, the aforementioned
function(s) cannot ever fail and they would always return ISC_R_SUCCESS.
Change the function(s) to return void and remove the extra checks in
the code that uses them.
(cherry picked from commit bbb4cdb92d)
Previously, the function(s) in the commit subject could fail for various
reasons - mostly allocation failures, or other functions returning
different return code than ISC_R_SUCCESS. Now, the aforementioned
function(s) cannot ever fail and they would always return ISC_R_SUCCESS.
Change the function(s) to return void and remove the extra checks in
the code that uses them.
(cherry picked from commit 8fa27365ec)
LibreSSL 3.5.0 fails to compile with these shims. We could have just
removed the LibreSSL check from the pre-processor condition, but it
seems that these shims are no longer needed because all the supported
versions of OpenSSL and LibreSSL have those functions.
According to EVP_ENCRYPTINIT(3) manual page in LibreSSL,
EVP_CIPHER_CTX_new() and EVP_CIPHER_CTX_free() first appeared in
OpenSSL 0.9.8b, and have been available since OpenBSD 4.5.
(cherry picked from commit a3789053682b57a2031de8c544134f1923e76cf3)
when parsing key pairs, if the '=' character fell at max_token
a protective INSIST preventing buffer overrun could be triggered.
Attempt to grow the buffer immediately before the INSIST.
Also removed an unnecessary INSIST on the opening double quote
of key buffer pair.
(cherry picked from commit 4c356d2770)
The isc__nmsocket_reset() was missing a case for raw TCP sockets (used
by RNDC and DoH) which would case a assertion failure when write timeout
would be triggered.
TCP sockets are now also properly handled in isc__nmsocket_reset().
(cherry picked from commit b220fb32bd)
When isc__nm_uvreq_t gets deactivated, it could be just put onto array
stack to be reused later to save some initialization time.
Unfortunately, this might hide some use-after-free errors.
Disable the inactive uvreqs caching when compiled with Address or
Thread Sanitizer.
(cherry picked from commit be339b3c83)
When isc_nmhandle_t gets deactivated, it could be just put onto array
stack to be reused later to safe some initialization time.
Unfortunately, this might hide some use-after-free errors.
Disable the inactive handles caching when compiled with Address or
Thread Sanitizer.
(cherry picked from commit 92cce1da65)
The isc__nmsocket_t has locked array of isc_nmhandle_t that's not used
for anything. The isc__nmhandle_get() adds the isc_nmhandle_t to the
locked array (and resized if necessary) and removed when
isc_nmhandle_put() finally destroys the handle. That's all it does, so
it serves no useful purpose.
Remove the .ah_handles, .ah_size, and .ah_frees members of the
isc__nmsocket_t and .ah_pos member of the isc_nmhandle_t struct.
(cherry picked from commit e2555a306f)
When the TCP, TCPDNS or TLSDNS connection times out, the isc__nm_uvreq_t
would be pushed into sock->inactivereqs before the uv_tcp_connect()
callback finishes. Because the isc__nmsocket_t keeps the list of
inactive isc__nm_uvreq_t, this would cause use-after-free only when the
sock->inactivereqs is full (which could never happen because the failure
happens in connection timeout callback) or when the sock->inactivereqs
mechanism is completely removed (f.e. when running under Address or
Thread Sanitizer).
Delay isc__nm_uvreq_t deallocation to the connection callback and only
signal the connection callback should be called by shutting down the
libuv socket from the connection timeout callback.
(cherry picked from commit 3268627916)
When the isc_netmgr is being destroyed, the normal and priority queues
should be dequeued and netievents properly freed. This wasn't the case.
(cherry picked from commit 88418c3372)
Use the isc_nmhandle_setwritetimeout() function in the netmgr unit test
to allow more time for writing and reading the responses because some of
the intervals that are used in the unit tests are really small leaving a
little room for any delays.
(cherry picked from commit ee359d6ffa)
In some situations (unit test and forthcoming XFR timeouts MR), we need
to modify the write timeout independently of the read timeout. Add a
isc_nmhandle_setwritetimeout() function that could be called before
isc_nm_send() to specify a custom write timeout interval.
(cherry picked from commit a89d9e0fa6)
When the outgoing TCP write buffers are full because the other party is
not reading the data, the uv_write() could wait indefinitely on the
uv_loop and never calling the callback. Add a new write timer that uses
the `tcp-idle-timeout` value to interrupt the TCP connection when we are
not able to send data for defined period of time.
(cherry picked from commit 408b362169)
The uv_tcp_close_reset() function was added in libuv 1.32.0 and since we
support older libuv releases, we have to add a shim uv_tcp_close_reset()
implementation loosely based on libuv.
(cherry picked from commit cd3b58622c)
Before adding the write timer, we have to remove the generic sock->timer
to sock->read_timer. We don't touch the function names to limit the
impact of the refactoring.
(cherry picked from commit 45a73c113f)
Replace the RUNTIME_CHECK() calls for libuv API calls with
UV_RUNTIME_CHECK() to get more detailed error message when
something fails and should not.
(cherry picked from commit 8715be1e4b)
When libuv functions fail, they return correct return value that could
be useful for more detailed debugging. Currently, we usually just check
whether the return value is 0 and invoke assertion error if it doesn't
throwing away the details why the call has failed. Unfortunately, this
often happen on more exotic platforms.
Add a UV_RUNTIME_CHECK() macro that can be used to print more detailed
error message (via uv_strerror() before ending the execution of the
program abruptly with the assertion.
(cherry picked from commit 62e15bb06d)
The task exclusive mode stops all processing (tasks and networking IO)
except the designated exclusive task events. This has impact on the
operation of the server. Add log messages indicating when we start the
exclusive mode, and when we end exclusive task mode.
(cherry picked from commit b9cb29076f)
The isc_thread_setaffinity call was removed in !5265 and we are not
going to restore it because it was proven that the performance is better
without it. Additionally, remove the already disabled cpu system test.
The isc_thread_setconcurrency function is unused and also calling
pthread_setconcurrency() on Linux has no meaning, formerly it was
added because of Solaris in 2001 and it was removed when taskmgr was
refactored to run on top of netmgr in !4918.
(cherry picked from commit 0500345513)
When isc_quota_attach_cb() API returns ISC_R_QUOTA (meaning hard quota
was reached) the accept_connection() would return without logging a
message about quota reached.
Change the connection callback to log the quota reached message.
(cherry picked from commit 2ae84702ad)
Apparently we forgot about DLZ when updating DNS_CLIENTINFO_VERSION
constant for ECS, which is at value "3" since ECS was introduced.
The code in example drivers and tests now hardcodes version numbers
2 (without ECS) and 3 (with ECS) depending on what a given code path
requires.
(cherry picked from commit f81debe1c8)
The commit itself is harmless, but at the same time it is also useless,
so we are reverting it.
This reverts commit 11c869a3d5.
(cherry picked from commit 0a4e91ee47)
Previously, the netmgr/udp.c tried to detect the recvmmsg detection in
libuv with #ifdef UV_UDP_<foo> preprocessor macros. However, because
the UV_UDP_<foo> are not preprocessor macros, but enum members, the
detection didn't work. Because the detection didn't work, the code
didn't have access to the information when we received the final chunk
of the recvmmsg and tried to free the uvbuf every time. Fortunately,
the isc__nm_free_uvbuf() had a kludge that detected attempt to free in
the middle of the receive buffer, so the code worked.
However, libuv 1.37.0 changed the way the recvmmsg was enabled from
implicit to explicit, and we checked for yet another enum member
presence with preprocessor macro, so in fact libuv recvmmsg support was
never enabled with libuv >= 1.37.0.
This commit changes to the preprocessor macros to autoconf checks for
declaration, so the detection now works again. On top of that, it's now
possible to cleanup the alloc_cb and free_uvbuf functions because now,
the information whether we can or cannot free the buffer is available to
us.
(cherry picked from commit 7370725008)
This commit converts the license handling to adhere to the REUSE
specification. It specifically:
1. Adds used licnses to LICENSES/ directory
2. Add "isc" template for adding the copyright boilerplate
3. Changes all source files to include copyright and SPDX license
header, this includes all the C sources, documentation, zone files,
configuration files. There are notes in the doc/dev/copyrights file
on how to add correct headers to the new files.
4. Handle the rest that can't be modified via .reuse/dep5 file. The
binary (or otherwise unmodifiable) files could have license places
next to them in <foo>.license file, but this would lead to cluttered
repository and most of the files handled in the .reuse/dep5 file are
system test files.
(cherry picked from commit 58bd26b6cf)
The isc__nm_tcp_resumeread() was using maybe_enqueue function to enqueue
netmgr event which could case the read callback to be executed
immediately if there was enough data waiting in the TCP queue.
If such thing would happen, the read callback would be called before the
previous read callback was finished and the worker receive buffer would
be still marked "in use" causing a assertion failure.
This would affect only raw TCP channels, e.g. rndc and http statistics.
(cherry picked from commit 11c869a3d5)
While doing code review, it was found that the taskmgr->exiting is set
under taskmgr->lock, but accessed under taskmgr->excl_lock in the
isc_task_beginexclusive().
Additionally, before the change that moved running the tasks to the
netmgr, the task_ready() subrouting of isc_task_detach() would lock
mgr->lock, requiring the mgr->excl to be protected mgr->excl_lock
to prevent deadlock in the code. After !4918 has been merged, this is
no longer true, and we can remove taskmgr->excl_lock and use
taskmgr->lock in its stead.
Solve both issues by removing the taskmgr->excl_lock and exclusively use
taskmgr->lock to protect both taskmgr->excl and taskmgr->exiting which
now doesn't need to be atomic_bool, because it's always accessed from
within the locked section.
(cherry picked from commit e705f213ca)
The isc_taskmgr_excltask() would return ISC_R_NOTFOUND either when the
exclusive task was not set (yet) or when the taskmgr is shutting down
and the exclusive task has been already cleared.
Distinguish between the two states and return ISC_R_SHUTTINGDOWN when
the taskmgr is being shut down instead of ISC_R_NOTFOUND.
(cherry picked from commit f9d90159b8)
For small sized allocations, the internal allocator gets the memory in
bigger blobs that gets splits into right-sized chunks. This increases
speed of small allocations and reduced the fragmentation, but such
memory is never released back to the operating system.
Disable the internal allocator by default, and add new `-M internal`
command line option to `named`.
