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
With the introduction of dnssec-policy, the aforementioned tools were
either rendered obsolete, or they will be replaced with dnssec-policy
based tools. Remove the tools and the requirement to have Python
installed. Python 3 is still being used for tests, so keep the autoconf
test, but make it much simpler.
The pk11/constants.h header contained static CK_BYTE arrays and
we had to use #defines to pull only those we need. This commit
changes the constants to only define byte arrays with the content
and either use them directly or define the CK_BYTE arrays locally
where used.
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.
MSVC documentation states: "This warning can be caused when a pointer to
a const or volatile item is assigned to a pointer not declared as
pointing to const or volatile."
Unfortunately, this happens when we dynamically allocate and deallocate
block of atomic variables using isc_mem_get and isc_mem_put.
Couple of examples:
lib\isc\hp.c(134): warning C4090: 'function': different 'volatile' qualifiers [C:\builds\isc-projects\bind9\lib\isc\win32\libisc.vcxproj]
lib\isc\hp.c(144): warning C4090: 'function': different 'volatile' qualifiers [C:\builds\isc-projects\bind9\lib\isc\win32\libisc.vcxproj]
lib\isc\stats.c(55): warning C4090: 'function': different 'volatile' qualifiers [C:\builds\isc-projects\bind9\lib\isc\win32\libisc.vcxproj]
lib\isc\stats.c(87): warning C4090: 'function': different 'volatile' qualifiers [C:\builds\isc-projects\bind9\lib\isc\win32\libisc.vcxproj]
The InterlockedOr8() and InterlockedAnd8() first argument was cast
to (atomic_int_fast8_t) instead of (atomic_int_fast8_t *), this was
reported by MSVC as:
warning C4024: '_InterlockedOr8': different types for formal and actual parameter 1
warning C4024: '_InterlockedAnd8': different types for formal and actual parameter 1
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 assembly code generated by MSVC for at least some signed comparisons
involving atomic variables incorrectly uses unsigned conditional jumps
instead of signed ones. In particular, the checks in isc_log_wouldlog()
are affected in a way which breaks logging on Windows and thus also all
system tests involving a named instance. Work around the issue by
assigning the values returned by atomic_load_acquire() calls in
isc_log_wouldlog() to local variables before performing comparisons.
The rwlock introduced to protect the .logconfig member of isc_log_t
structure caused a significant performance drop because of the rwlock
contention. It was also found, that the debug_level member of said
structure was not protected from concurrent read/writes.
The .dynamic and .highest_level members of isc_logconfig_t structure
were actually just cached values pulled from the assigned channels.
We introduced an even higher cache level for .dynamic and .highest_level
members directly into the isc_log_t structure, so we don't have to
access the .logconfig member in the isc_log_wouldlog() function.
We could have a race between handle closing and processing async
callback. Deactivate the handle before issuing the callback - we
have the socket referenced anyway so it's not a problem.
We introduce a isc_quota_attach_cb function - if ISC_R_QUOTA is returned
at the time the function is called, then a callback will be called when
there's quota available (with quota already attached). The callbacks are
organized as a LIFO queue in the quota structure.
It's needed for TCP client quota - with old networking code we had one
single place where tcp clients quota was processed so we could resume
accepting when the we had spare slots, but it's gone with netmgr - now
we need to notify the listener/accepter that there's quota available so
that it can resume accepting.
Remove unused isc_quota_force() function.
The isc_quote_reserve and isc_quota_release were used only internally
from the quota.c and the tests. We should not expose API we are not
using.
tcpdns used transport-specific functions to operate on the outer socket.
Use generic ones instead, and select the proper call in netmgr.c.
Make the missing functions (e.g. isc_nm_read) generic and add type-specific
calls (isc__nm_tcp_read). This is the preparation for netmgr TLS layer.
In isc_log_woudlog() the .logconfig member of isc_log_t structure was
accessed unlocked on the merit that there could be just a race when
.logconfig would be NULL, so the message would not be logged. This
turned not to be true, as there's also data race deeper. The accessed
isc_logconfig_t object could be in the middle of destruction, so the
pointer would be still non-NULL, but the structure members could point
to a chunk of memory no longer belonging to the object. Since we are
only accessing integer types (the log level), this would never lead to
a crash, it leads to memory access to memory area no longer belonging to
the object and this a) wrong, b) raises a red flag in thread-safety tools.
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.
The <isc/md.h> header directly included <openssl/evp.h> header which
enforced all users of the libisc library to explicitly list the include
path to OpenSSL and link with -lcrypto. By hiding the specific
implementation into the private namespace, we no longer enforce this.
In the long run, this might also allow us to switch cryptographic
library implementation without affecting the downstream users.
While making the isc_md_type_t type opaque, the API using the data type
was changed to use the pointer to isc_md_type_t instead of using the
type directly.
The <isc/md.h> header directly included <openssl/hmac.h> header which
enforced all users of the libisc library to explicitly list the include
path to OpenSSL and link with -lcrypto. By hiding the specific
implementation into the private namespace, we no longer enforce this.
In the long run, this might also allow us to switch cryptographic
library implementation without affecting the downstream users.
The two "functions" that isc/safe.h declared before were actually simple
defines to matching OpenSSL functions. The downside of the approach was
enforcing all users of the libisc library to explicitly list the include
path to OpenSSL and link with -lcrypto. By hiding the specific
implementation into the private namespace changing the defines into
simple functions, we no longer enforce this. In the long run, this
might also allow us to switch cryptographic library implementation
without affecting the downstream users.
The previous commit removed the code related to the internal symbol
table. On platforms where available, we can now use backtrace_symbols()
to print more verbose symbols table to the output.
As there's now general availability of backtrace() and
backtrace_symbols() functions (see below), the commit also removes the
usage of glibc internals and the custom stack tracing.
* backtrace(), backtrace_symbols(), and backtrace_symbols_fd() are
provided in glibc since version 2.1.
* backtrace(), backtrace_symbols(), and backtrace_symbols_fd() first
appeared in Mac OS X 10.5.
* The backtrace() library of functions first appeared in NetBSD 7.0 and
FreeBSD 10.0.
A data race was happening while BIND was starting due to
isc_log_wouldlog function accessing lctx->logconfig without a lock.
To prevent that without incurring much costs, that variable was made
atomic.
This commit fixes isc_glob function on windows environments.
The file_list_t * object pointed to by pglob->reserved was missing
ISC_LIST_INIT intialization macro.
