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.
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)
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 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)
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)
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)
The current implementation of isc_queue uses Michael-Scott lock-free
queue that in turn uses hazard pointers. It was discovered that the way
we use the isc_queue, such complicated mechanism isn't really needed,
because most of the time, we either execute the work directly when on
nmthread (in case of UDP) or schedule the work from the matching
nmthreads.
Replace the current implementation of the isc_queue with a simple locked
ISC_LIST. There's a slight improvement - since copying the whole list
is very lightweight - we move the queue into a new list before we start
the processing and locking just for moving the queue and not for every
single item on the list.
NOTE: There's a room for future improvements - since we don't guarantee
the order in which the netievents are processed, we could have two lists
- one unlocked that would be used when scheduling the work from the
matching thread and one locked that would be used from non-matching
thread.
(cherry picked from commit 6bd025942c)
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)
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)
the addition of support for ECS client information in DLZ
modules omitted some necessary changes to build modules
in contrib.
(cherry picked from commit d3fed6f400)
IBM power architecture has L1 cache line size equal to 128. Take
advantage of that on that architecture, do not force more common value
of 64. When it is possible to detect higher value, use that value
instead. Keep the default to be 64.
(cherry picked from commit f00f521e9c)
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.
The isc_queue_new() was using dirty tricks to allocate the head and tail
members of the struct aligned to the cacheline. We can now use
isc_mem_get_aligned() to allocate the structure to the cacheline
directly.
Use ISC_OS_CACHELINE_SIZE (64) instead of arbitrary ALIGNMENT (128), one
cacheline size is enough to prevent false sharing.
Cleanup the unused max_threads variable - there was actually no limit on
the maximum number of threads. This was changed a while ago.
There are some situations where having aligned allocations would be
useful, so we don't have to play tricks with padding the data to the
cacheline sizes.
Add isc_mem_{get,put,reget,putanddetach}_aligned() functions that has
alignment and size as last argument mimicking the POSIX posix_memalign()
functions on systems with jemalloc (see the documentation on
MALLOX_ALIGN() for more details). On systems without jemalloc, those
functions are same as non-aligned variants.
Add library ctor and dtor for isc_os compilation unit which initializes
the numbers of the CPUs and also checks whether L1 cacheline size is
really 64 if the sysconf() call is available.
For consistency with similar functions, rename `pcache` to `cachep`,
call a separate destroy function when references reach 0, and add
a missing call to isc_refcount_destroy().
This commit adds a TLS context object cache implementation. The
intention of having this object is manyfold:
- In the case of client-side contexts: allow reusing the previously
created contexts to employ the context-specific TLS session resumption
cache. That will enable XoT connection to be reestablished faster and
with fewer resources by not going through the full TLS handshake
procedure.
- In the case of server-side contexts: reduce the number of contexts
created on startup. That could reduce startup time in a case when
there are many "listen-on" statements referring to a smaller amount of
`tls` statements, especially when "ephemeral" certificates are
involved.
- The long-term goal is to provide in-memory storage for additional
data associated with the certificates, like runtime
representation (X509_STORE) of intermediate CA-certificates bundle for
Strict TLS/Mutual TLS ("ca-file").
TLS pre-master secrets will be dumped to disk using the logging
framework provided by libisc. Add a new logging category for this type
of debugging data in order to enable exporting it to a dedicated
channel. Derive the name of the new category from the name of the
relevant environment variable, SSLKEYLOGFILE.
OpenSSL 3.0.1 does not accept 0 as a digest buffer length when
calling EVP_DigestSignFinal as it now checks that the digest buffer
length is large enough for the digest. Pass the digest buffer
length instead.
Mutex debugging code (used when the ISC_MUTEX_DEBUG preprocessor macro
is set to 1 and PTHREAD_MUTEX_ERRORCHECK is defined) has been broken for
the past 3 years (since commit 2f3eee5a4f)
and nobody complained, which is a strong indication that this code is
not being used these days any more. External tools for detecting
locking issues are already wired into various GitLab CI checks. Drop
all code depending on the ISC_MUTEX_DEBUG preprocessor macro being set.
Mutex profiling code (used when the ISC_MUTEX_PROFILE preprocessor macro
is set to 1) has been broken for the past 3 years (since commit
0bed9bfc28) and nobody complained, which
is a strong indication that this code is not being used these days any
more. External tools for both measuring performance and detecting
locking issues are already wired into various GitLab CI checks. Drop
all code depending on the ISC_MUTEX_PROFILE preprocessor macro being
set.
This commit adds an isc_nm_socket_type() function which can be used to
obtain a handle's socket type.
This change obsoletes isc_nm_is_tlsdns_handle() and
isc_nm_is_http_handle(). However, it was decided to keep the latter as
we eventually might end up supporting multiple HTTP versions.
Change 5756 (GL #2854) introduced build errors when using
'configure --disable-doh'. To fix this, isc_nm_is_http_handle() is
now defined in all builds, not just builds that have DoH enabled.
Missing code comments were added both for that function and for
isc_nm_is_tlsdns_handle().
This commit adds an isc_nm_set_min_answer_ttl() function which is
intended to to be used to give a hint to the underlying transport
regarding the answer TTL.
The interface is intentionally kept generic because over time more
transports might benefit from this functionality, but currently it is
intended for DoH to set "max-age" value within "Cache-Control" HTTP
header (as recommended in the RFC8484, section 5.1 "Cache
Interaction").
It is no-op for other DNS transports for the time being.
isc_nm_routeconnect() opens a route/netlink socket, then calls a
connect callback, much like isc_nm_udpconnect(), with a handle that
can then be monitored for network changes.
Internally the socket is treated as a UDP socket, since route/netlink
sockets follow the datagram contract.
The __builtin_expect() can be used to provide the compiler with branch
prediction information. The Gcc manual says[1] on the subject:
In general, you should prefer to use actual profile feedback for
this (-fprofile-arcs), as programmers are notoriously bad at
predicting how their programs actually perform.
Stop using __builtin_expect() and ISC_LIKELY() and ISC_UNLIKELY() macros
to provide the branch prediction information as the performance testing
shows that named performs better when the __builtin_expect() is not
being used.
1. https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#index-_005f_005fbuiltin_005fexpect
Unify the header guard style and replace the inconsistent include guards
with #pragma once.
The #pragma once is widely and very well supported in all compilers that
BIND 9 supports, and #pragma once was already in use in several new or
refactored headers.
Using simpler method will also allow us to automate header guard checks
as this is simpler to programatically check.
For reference, here are the reasons for the change taken from
Wikipedia[1]:
> In the C and C++ programming languages, #pragma once is a non-standard
> but widely supported preprocessor directive designed to cause the
> current source file to be included only once in a single compilation.
>
> Thus, #pragma once serves the same purpose as include guards, but with
> several advantages, including: less code, avoidance of name clashes,
> and sometimes improvement in compilation speed. On the other hand,
> #pragma once is not necessarily available in all compilers and its
> implementation is tricky and might not always be reliable.
1. https://en.wikipedia.org/wiki/Pragma_once
Replace some "master/slave" terminology in the code with the preferred
"primary/secondary" keywords. This also changes user output such as
log messages, and fixes a typo ("seconary") in cfg_test.c.
There are still some references to "master" and "slave" for various
reasons:
- The old syntax can still be used as a synonym.
- The master syntax is kept when it refers to master files and formats.
- This commit replaces mainly keywords that are local. If "master" or
"slave" is used in for example a structure that is all over the
place, it is considered out of scope for the moment.
Remove the dynamic registration of result codes. Convert isc_result_t
from unsigned + #defines into 32-bit enum type in grand unified
<isc/result.h> header. Keep the existing values of the result codes
even at the expense of the description and identifier tables being
unnecessary large.
Additionally, add couple of:
switch (result) {
[...]
default:
break;
}
statements where compiler now complains about missing enum values in the
switch statement.
Previously, when using compiler without support for static assertions,
the STATIC_ASSERT() macro would be replaced with runtime assertion.
Change the STATIC_ASSERT() macro to a version that's compile time
assertion even when using pre-C11 compilers.
Courtesy of Joseph Quinsey: https://godbolt.org/z/K9RvWS
This commit makes BIND verify that zone transfers are allowed to be
done over the underlying connection. Currently, it makes sense only
for DoT, but the code is deliberately made to be protocol-agnostic.
The intention of having this function is to have a predicate to check
if a zone transfer could be performed over the given handle. In most
cases we can assume that we can do zone transfers over any stream
transport except DoH, but this assumption will not work for zone
transfers over DoT (XoT), as the RFC9103 requires ALPN to happen,
which might not be the case for all deployments of DoT.
- Responses received by the dispatch are no longer sent to the caller
via a task event, but via a netmgr-style recv callback. the 'action'
parameter to dns_dispatch_addresponse() is now called 'response' and
is called directly from udp_recv() or tcp_recv() when a valid response
has been received.
- All references to isc_task and isc_taskmgr have been removed from
dispatch functions.
- All references to dns_dispatchevent_t have been removed and the type
has been deleted.
- Added a task to the resolver response context, to be used for fctx
events.
- When the caller cancels an operation, the response handler will be
called with ISC_R_CANCELED; it can abort immediately since the caller
will presumably have taken care of cleanup already.
- Cleaned up attach/detach in resquery and request.
