This commit separates TLS context creation code from xfrin_start() as
it has become too large and hard to follow into a new
function (similarly how it is done in dighost.c)
The dead code has been removed from the cleanup section of the TLS
creation code:
* there is no way 'tlsctx' can equal 'found';
* there is no way 'sess_cache' can be non-NULL in the cleanup section.
Also, it fixes a bug in the older version of the code, where TLS
client session context fetched from the cache would not get passed to
isc_nm_tlsdnsconnect().
(cherry picked from commit 98f758ed4f)
The recently added TLS client session cache used
SSL_SESSION_is_resumable() to avoid polluting the cache with
non-resumable sessions. However, it turned out that we cannot provide
a shim for this function across the whole range of OpenSSL versions
due to the fact that OpenSSL 1.1.0 does uses opaque pointers for
SSL_SESSION objects.
The commit replaces the shim for SSL_SESSION_is_resumable() with a non
public approximation of it on systems shipped with OpenSSL 1.1.0. It
is not turned into a proper shim because it does not fully emulate the
behaviour of SSL_SESSION_is_resumable(), but in our case it is good
enough, as it still helps to protect the cache from pollution.
For systems shipped with OpenSSL 1.0.X and derivatives (e.g. older
versions of LibreSSL), the provided replacement perfectly mimics the
function it is intended to replace.
(cherry picked from commit 40be3c9263)
The commit fixes a corner case in client-side DoH code, when a write
attempt is done on a closing socket (session).
The change ensures that the write call-back will be called with a
proper error code (see failed_send_cb() call in client_httpsend()).
(cherry picked from commit 9abb00bb5f)
In such a case it will return UV_EINVAL (-EINVAL), leading to
aborting, as the code expects the function to succeed.
(cherry picked from commit 245f7cec2e)
This commit extends DoT code with TLS client session resumption
support implemented on top of the TLS client session cache.
(cherry picked from commit 86465c1dac)
This commit extends TLS stream code and DoH code with TLS client
session resumption support implemented on top of the TLS client
session cache.
(cherry picked from commit 90bc13a5d5)
This commit extends TLS context cache with TLS client session cache so
that an associated session cache can be stored alongside the TLS
context within the context cache.
(cherry picked from commit 987892d113)
This commit adds an implementation of a client TLS session cache. TLS
client session cache is an object which allows efficient storing and
retrieval of previously saved TLS sessions so that they can be
resumed. This object is supposed to be a foundation for implementing
TLS session resumption - a standard technique to reduce the cost of
re-establishing a connection to the remote server endpoint.
OpenSSL does server-side TLS session caching transparently by
default. However, on the client-side, a TLS session to resume must be
manually specified when establishing the TLS connection. The TLS
client session cache is precisely the foundation for that.
(cherry picked from commit 4ef40988f3)
Before the changes from this commit were introduced, the accept
callback function will get called twice when accepting connection
during two of these stages:
* when accepting the TCP connection;
* when handshake has completed.
That is clearly an error, as it should have been called only once. As
far as I understand it the mistake is a result of TLS DNS transport
being essentially a fork of TCP transport, where calling the accept
callback immediately after accepting TCP connection makes sense.
This commit fixes this mistake. It did not have any very serious
consequences because in BIND the accept callback only checks an ACL
and updates stats.
(cherry picked from commit e616d7f240)
Under specific rare timing circumstances the uv_read_start() could
fail with UV_EINVAL when the connection is reset between the connect (or
accept) and the uv_read_start() call on the nmworker loop. Handle such
situation gracefully by propagating the errors from uv_read_start() into
upper layers, so the socket can be internally closed().
(cherry picked from commit b432d5d3bc)
The unit tests are now using a common base, which means that
lib/dns/tests/ code now has to include lib/isc/include/isc/test.h and
link with lib/isc/test.c and lib/ns/tests has to include both libisc and
libdns parts.
Instead of cross-linking code between the directories, move the
/lib/<foo>/test.c to /tests/<foo>.c and /lib/<foo>/include/<foo>test.h
to /tests/include/tests/<foo>.h and create a single libtest.la
convenience library in /tests/.
At the same time, move the /lib/<foo>/tests/ to /tests/<foo>/ (but keep
it symlinked to the old location) and adjust paths accordingly. In few
places, we are now using absolute paths instead of relative paths,
because the directory level has changed. By moving the directories
under the /tests/ directory, the test-related code is kept in a single
place and we can avoid referencing files between libns->libdns->libisc
which is unhealthy because they live in a separate Makefile-space.
In the future, the /bin/tests/ should be merged to /tests/ and symlink
kept, and the /fuzz/ directory moved to /tests/fuzz/.
(cherry picked from commit 2c3b2dabe9)
The unit tests contain a lot of duplicated code and here's an attempt
to reduce code duplication.
This commit does several things:
1. Remove #ifdef HAVE_CMOCKA - we already solve this with automake
conditionals.
2. Create a set of ISC_TEST_* and ISC_*_TEST_ macros to wrap the test
implementations, test lists, and the main test routine, so we don't
have to repeat this all over again. The macros were modeled after
libuv test suite but adapted to cmocka as the test driver.
A simple example of a unit test would be:
ISC_RUN_TEST_IMPL(test1) { assert_true(true); }
ISC_TEST_LIST_START
ISC_TEST_ENTRY(test1)
ISC_TEST_LIST_END
ISC_TEST_MAIN (Discussion: Should this be ISC_TEST_RUN ?)
For more complicated examples including group setup and teardown
functions, and per-test setup and teardown functions.
3. The macros prefix the test functions and cmocka entries, so the name
of the test can now match the tested function name, and we don't have
to append `_test` because `run_test_` is automatically prepended to
the main test function, and `setup_test_` and `teardown_test_` is
prepended to setup and teardown function.
4. Update all the unit tests to use the new syntax and fix a few bits
here and there.
5. In the future, we can separate the test declarations and test
implementations which are going to greatly help with uncluttering the
bigger unit tests like doh_test and netmgr_test, because the test
implementations are not declared static (see `ISC_RUN_TEST_DECLARE`
and `ISC_RUN_TEST_IMPL` for more details.
NOTE: This heavily relies on preprocessor macros, but the result greatly
outweighs all the negatives of using the macros. There's less
duplicated code, the tests are more uniform and the implementation can
be more flexible.
(cherry picked from commit 63fe9312ff)
Typing from libuv structure to isc_region_t is not possible, because
their sizes differ on 64 bit architectures. Little endian machines seems
to be lucky and still result in test passed. But big endian machine such
as s390x fails the test reliably.
Fix by directly creating the buffer as isc_region_t and skipping the
type conversion. More readable and still more correct.
(cherry picked from commit 057438cb45)
Setting the sock->write_timeout from the TCP, TCPDNS, and TLSDNS send
functions could lead to (harmless) data race when setting the value for
the first time when the isc_nm_send() function would be called from
thread not-matching the socket we are sending to. Move the setting the
sock->write_timeout to the matching async function which is always
called from the matching thread.
(cherry picked from commit 61117840c1)
Clang added support for the gcc-style fallthrough
attribute (i.e. __attribute__((fallthrough))) in version 10. However,
__has_attribute(fallthrough) will return 1 in C mode in older versions,
even though they only support the C++11 fallthrough attribute. At best,
the unsupported attribute is simply ignored; at worst, it causes errors.
The C2x fallthrough attribute has the advantages of being supported in
the broadest range of clang versions (added in version 9) and being easy
to check for support. Use C2x [[fallthrough]] attribute if possible, and
fall back to not using an attribute for clang versions that don't have
it.
Courtesy of Joshua Root
(cherry picked from commit 14c8d43863)
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)
This commit fixes a crash in generic TLS stream code, which could be
reproduced during some runs of the 'sslyze' tool.
The intention of this commit is twofold.
Firstly, it ensures that the TLS socket object cannot be destroyed too
early. Now it is being deleted alongside the underlying TCP socket
object.
Secondly, it ensures that the TLS socket object cannot be destroyed as
a result of calling 'tls_do_bio()' (the primary function which
performs encryption/decryption during the IO) as the code did not
expect that. This code path is fixed now.
(cherry picked from commit a696be6a2d)
This commit adds support for ISC_R_TLSBADPEERCERT error code, which is
supposed to be used to signal for TLS peer certificates verification
in dig and other code.
The support for this error code is added to our TLS and TLS DNS
implementations.
This commit also adds isc_nm_verify_tls_peer_result_string() function
which is supposed to be used to get a textual description of the
reason for getting a ISC_R_TLSBADPEERCERT error.
This commit adds support for keeping CA certificates stores associated
with TLS contexts. The intention is to keep one reusable store per a
set of related TLS contexts.
This commit adds a set of functions that can be used to implement
Strict and Mutual TLS:
* isc_tlsctx_load_client_ca_names();
* isc_tlsctx_load_certificate();
* isc_tls_verify_peer_result_string();
* isc_tlsctx_enable_peer_verification().
This commit adds a set of high-level utility functions to manipulate
the certificate stores. The stores are needed to implement TLS
certificates verification efficiently.
This commit adds isc_nmsocket_set_tlsctx() - an asynchronous function
that replaces the TLS context within a given TLS-enabled listener
socket object. It is based on the newly added reference counting
functionality.
The intention of adding this function is to add functionality to
replace a TLS context without recreating the whole socket object,
including the underlying TCP listener socket, as a BIND process might
not have enough permissions to re-create it fully on reconfiguration.
The implementation is done on top of the reference counting
functionality found in OpenSSL/LibreSSL, which allows for avoiding
wrapping the object.
Adding this function allows using reference counting for TLS contexts
in BIND 9's codebase.
This commit ensures that write callbacks are getting called only after
the data has been sent via the network.
Without this fix, a situation could appear when a write callback could
get called before the actual encrypted data would have been sent to
the network. Instead, it would get called right after it would have
been passed to the OpenSSL (i.e. encrypted).
Most likely, the issue does not reveal itself often because the
callback call was asynchronous, so in most cases it should have been
called after the data has been sent, but that was not guaranteed by
the code logic.
Also, this commit removes one memory allocation (netievent) from a hot
path, as there is no need to call this callback asynchronously
anymore.
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)
The shutdown() is part of standard library (POSIX-1), don't use such
name in the timer_test.c, but rather rename it to test_shutdown().
(cherry picked from commit 7868d8145b)
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)
Previously, the RPZ updates ran quantized on the main nm_worker loops.
As the quantum was set to 1024, this might lead to service
interruptions when large RPZ update was processed.
Change the RPZ update process to run as the offloaded work. The update
and cleanup loops were refactored to do as little locking of the
maintenance lock as possible for the shortest periods of time and the db
iterator is being paused for every iteration, so we don't hold the rbtdb
tree lock for prolonged periods of time.
(cherry picked from commit f106d0ed2b)
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().
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)
C11 has builtin support for _Noreturn function specifier with
convenience noreturn macro defined in <stdnoreturn.h> header.
Replace ISC_NORETURN macro by C11 noreturn with fallback to
__attribute__((noreturn)) if the C11 support is not complete.
(cherry picked from commit 04d0b70ba2)
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)
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.
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.
In httpd.c, the send callback can directly call read callback without
calling isc_nm_resumeread(). When per-send timeout was added, this
could lead to use-after-free when shutting down the named.
Cleanup the way how we attach to .readhandle and .sendhandle, so there's
assurance that .readhandle will be always non-NULL when reading and
.sendhandle will be always non-NULL when sending.
Additionally, it was found that the implementation ignored the
"Connection: close" header and it worked only accidentally by closing
the connection after the first read from the TCP socket. This has been
also fixed.
(cherry picked from commit 49c804f8b7)
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)
