The TIME_NOW macro calls isc_time_now which uses CLOCK_REALTIME_COARSE
for getting the current time. This is perfectly fine for millisecond,
however when the user request microsecond resolutiuon, they are going
to get very inaccurate results. This is especially true on a server
class machine where the clock ticks may be set to 100HZ.
This changes dig to use the new TIME_NOW_HIRES macro that uses the
CLOCK_MONOTONIC_RAW that is more expensive, but gets the *actual*
current time rather than the at the last kernel time tick.
On 24-core machine, the tests would crash because we would run out of
the hazard pointers. We now adjust the number of hazard pointers to be
in the <128,256> interval based on the number of available cores.
Note: This is just a band-aid and needs a proper fix.
The <isc/readline.h> header provided a compatibility shim to use when
other non-GNU readline libraries are in use. The two places where
readline library is being used is nslookup and nsupdate, so the header
file has been moved to bin/dig directory and it's directly included from
bin/nsupdate.
This also conceals any readline headers exposed from the libisc headers.
* Following the example set in 634bdfb16d8, the tlsdns netmgr
module now uses libuv and SSL primitives directly, rather than
opening a TLS socket which opens a TCP socket, as the previous
model was difficult to debug. Closes#2335.
* Remove the netmgr tls layer (we will have to re-add it for DoH)
* Add isc_tls API to wrap the OpenSSL SSL_CTX object into libisc
library; move the OpenSSL initialization/deinitialization from dstapi
needed for OpenSSL 1.0.x to the isc_tls_{initialize,destroy}()
* Add couple of new shims needed for OpenSSL 1.0.x
* When LibreSSL is used, require at least version 2.7.0 that
has the best OpenSSL 1.1.x compatibility and auto init/deinit
* Enforce OpenSSL 1.1.x usage on Windows
* Added a TLSDNS unit test and implemented a simple TLSDNS echo
server and client.
This is a part of the works that intends to make the netmgr stable,
testable, maintainable and tested. It contains a numerous changes to
the netmgr code and unfortunately, it was not possible to split this
into smaller chunks as the work here needs to be committed as a complete
works.
NOTE: There's a quite a lot of duplicated code between udp.c, tcp.c and
tcpdns.c and it should be a subject to refactoring in the future.
The changes that are included in this commit are listed here
(extensively, but not exclusively):
* The netmgr_test unit test was split into individual tests (udp_test,
tcp_test, tcpdns_test and newly added tcp_quota_test)
* The udp_test and tcp_test has been extended to allow programatic
failures from the libuv API. Unfortunately, we can't use cmocka
mock() and will_return(), so we emulate the behaviour with #define and
including the netmgr/{udp,tcp}.c source file directly.
* The netievents that we put on the nm queue have variable number of
members, out of these the isc_nmsocket_t and isc_nmhandle_t always
needs to be attached before enqueueing the netievent_<foo> and
detached after we have called the isc_nm_async_<foo> to ensure that
the socket (handle) doesn't disappear between scheduling the event and
actually executing the event.
* Cancelling the in-flight TCP connection using libuv requires to call
uv_close() on the original uv_tcp_t handle which just breaks too many
assumptions we have in the netmgr code. Instead of using uv_timer for
TCP connection timeouts, we use platform specific socket option.
* Fix the synchronization between {nm,async}_{listentcp,tcpconnect}
When isc_nm_listentcp() or isc_nm_tcpconnect() is called it was
waiting for socket to either end up with error (that path was fine) or
to be listening or connected using condition variable and mutex.
Several things could happen:
0. everything is ok
1. the waiting thread would miss the SIGNAL() - because the enqueued
event would be processed faster than we could start WAIT()ing.
In case the operation would end up with error, it would be ok, as
the error variable would be unchanged.
2. the waiting thread miss the sock->{connected,listening} = `true`
would be set to `false` in the tcp_{listen,connect}close_cb() as
the connection would be so short lived that the socket would be
closed before we could even start WAIT()ing
* The tcpdns has been converted to using libuv directly. Previously,
the tcpdns protocol used tcp protocol from netmgr, this proved to be
very complicated to understand, fix and make changes to. The new
tcpdns protocol is modeled in a similar way how tcp netmgr protocol.
Closes: #2194, #2283, #2318, #2266, #2034, #1920
* The tcp and tcpdns is now not using isc_uv_import/isc_uv_export to
pass accepted TCP sockets between netthreads, but instead (similar to
UDP) uses per netthread uv_loop listener. This greatly reduces the
complexity as the socket is always run in the associated nm and uv
loops, and we are also not touching the libuv internals.
There's an unfortunate side effect though, the new code requires
support for load-balanced sockets from the operating system for both
UDP and TCP (see #2137). If the operating system doesn't support the
load balanced sockets (either SO_REUSEPORT on Linux or SO_REUSEPORT_LB
on FreeBSD 12+), the number of netthreads is limited to 1.
* The netmgr has now two debugging #ifdefs:
1. Already existing NETMGR_TRACE prints any dangling nmsockets and
nmhandles before triggering assertion failure. This options would
reduce performance when enabled, but in theory, it could be enabled
on low-performance systems.
2. New NETMGR_TRACE_VERBOSE option has been added that enables
extensive netmgr logging that allows the software engineer to
precisely track any attach/detach operations on the nmsockets and
nmhandles. This is not suitable for any kind of production
machine, only for debugging.
* The tlsdns netmgr protocol has been split from the tcpdns and it still
uses the old method of stacking the netmgr boxes on top of each other.
We will have to refactor the tlsdns netmgr protocol to use the same
approach - build the stack using only libuv and openssl.
* Limit but not assert the tcp buffer size in tcp_alloc_cb
Closes: #2061
This commit extends the perl Configure script to also check for libssl
in addition to libcrypto and change the vcxproj source files to link
with both libcrypto and libssl.
The recv_done() callback had many exit paths with different conditions,
and every path had it's own set of destructors. The refactored code now
has unified exit path with descriptive goto labels matching the intent:
- cancel_lookup
- next_lookup
- detach_query
- keep_query
The only exception to the rule is check_for_more_data() path, where the
part of the query gets reused, so the query->readhandle and query gets
detached on it's own, and by going to the keep_query, we are just
skipping calling the destructors again.
FreeBSD sometimes returns spurious errors in UDP connect() attempts,
so we try a few times before giving up. However, each failed attempt
triggers a call to udp_ready() in dighost.c, and that was causing
the query object to be detached prematurely.
Sometimes, the dig_lookup_t could be destroyed before the final
send_done() callback was be called, leading to dereferencing an
already freed dig_lookup_t object. By making the dig_lookup_t
reference counted, we are ensuring that it won't be freed until
the last reference (from dig_query_t .lookup) is released.
because dig now uses the netmgr, printing of response messages
happens in a different thread than setup. the IDN output filtering
procedure, which set using dns_name_settotextfilter(), is stored as
thread-local data, and so if it's set during setup, it won't be
accessible when printing. we now set it immediately before printing,
in the same thread, and clear it immedately afterward.
The network manager does not support returning UDP datagrams to
clients from unexpected sources; it is therefore not possible for
dig to accept them. The "+[no]unexpected" option has therefore
been removed from the dig command and its documentation.
The dns_message_create() function cannot soft fail (as all memory
allocations either succeed or cause abort), so we change the function to
return void and cleanup the calls.
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
The ARM and the manpages have been converted into Sphinx documentation
format.
Sphinx uses reStructuredText as its markup language, and many of its
strengths come from the power and straightforwardness of
reStructuredText and its parsing and translating suite, the Docutils.
The rewrite of BIND 9 build system is a large work and cannot be reasonable
split into separate merge requests. Addition of the automake has a positive
effect on the readability and maintainability of the build system as it is more
declarative, it allows conditional and we are able to drop all of the custom
make code that BIND 9 developed over the years to overcome the deficiencies of
autoconf + custom Makefile.in files.
This squashed commit contains following changes:
- conversion (or rather fresh rewrite) of all Makefile.in files to Makefile.am
by using automake
- the libtool is now properly integrated with automake (the way we used it
was rather hackish as the only official way how to use libtool is via
automake
- the dynamic module loading was rewritten from a custom patchwork to libtool's
libltdl (which includes the patchwork to support module loading on different
systems internally)
- conversion of the unit test executor from kyua to automake parallel driver
- conversion of the system test executor from custom make/shell to automake
parallel driver
- The GSSAPI has been refactored, the custom SPNEGO on the basis that
all major KRB5/GSSAPI (mit-krb5, heimdal and Windows) implementations
support SPNEGO mechanism.
- The various defunct tests from bin/tests have been removed:
bin/tests/optional and bin/tests/pkcs11
- The text files generated from the MD files have been removed, the
MarkDown has been designed to be readable by both humans and computers
- The xsl header is now generated by a simple sed command instead of
perl helper
- The <irs/platform.h> header has been removed
- cleanups of configure.ac script to make it more simpler, addition of multiple
macros (there's still work to be done though)
- the tarball can now be prepared with `make dist`
- the system tests are partially able to run in oot build
Here's a list of unfinished work that needs to be completed in subsequent merge
requests:
- `make distcheck` doesn't yet work (because of system tests oot run is not yet
finished)
- documentation is not yet built, there's a different merge request with docbook
to sphinx-build rst conversion that needs to be rebased and adapted on top of
the automake
- msvc build is non functional yet and we need to decide whether we will just
cross-compile bind9 using mingw-w64 or fix the msvc build
- contributed dlz modules are not included neither in the autoconf nor automake
All our MSVS Project files share the same intermediate directory. We
know that this doesn't cause any problems, so we can just disable the
detection in the project files.
Example of the warning:
warning MSB8028: The intermediate directory (.\Release\) contains files shared from another project (dnssectool.vcxproj). This can lead to incorrect clean and rebuild behavior.
Our vcxproj files set the WarningLevel to Level3, which is too verbose
for a code that needs to be portable. That basically leads to ignoring
all the errors that MSVC produces. This commits downgrades the
WarningLevel to Level1 and enables treating warnings as errors for
Release builds. For the Debug builds the WarningLevel got upgraded to
Level4, and treating warnings as errors is explicitly disabled.
We should eventually make the code clean of all MSVC warnings, but it's
a long way to go for Level4, so it's more reasonable to start at Level1.
For reference[1], these are the warning levels as described by MSVC
documentation:
* /W0 suppresses all warnings. It's equivalent to /w.
* /W1 displays level 1 (severe) warnings. /W1 is the default setting
in the command-line compiler.
* /W2 displays level 1 and level 2 (significant) warnings.
* /W3 displays level 1, level 2, and level 3 (production quality)
warnings. /W3 is the default setting in the IDE.
* /W4 displays level 1, level 2, and level 3 warnings, and all level 4
(informational) warnings that aren't off by default. We recommend
that you use this option to provide lint-like warnings. For a new
project, it may be best to use /W4 in all compilations. This option
helps ensure the fewest possible hard-to-find code defects.
* /Wall displays all warnings displayed by /W4 and all other warnings
that /W4 doesn't include — for example, warnings that are off by
default.
* /WX treats all compiler warnings as errors. For a new project, it
may be best to use /WX in all compilations; resolving all warnings
ensures the fewest possible hard-to-find code defects.
1. https://docs.microsoft.com/en-us/cpp/build/reference/compiler-option-warning-level?view=vs-2019
The isc_mem API now crashes on memory allocation failure, and this is
the next commit in series to cleanup the code that could fail before,
but cannot fail now, e.g. isc_result_t return type has been changed to
void for the isc_log API functions that could only return ISC_R_SUCCESS.
On Windows, C11 localtime_r() and gmtime_r() functions are not
available. While localtime() and gmtime() functions are already thread
safe because they use Thread Local Storage, it's quite ugly to #ifdef
around every localtime_r() and gmtime_r() usage to make the usage also
thread-safe on POSIX platforms.
The commit adds wrappers around Windows localtime_s() and gmtime_s()
functions.
NOTE: The implementation of localtime_s and gmtime_s in Microsoft CRT
are incompatible with the C standard since it has reversed parameter
order and errno_t return type.
