xmlInitThreads() and xmlCleanupThreads() are called from within
ns_statschannels_configure() and ns_statschannels_shutdown(),
respectively. Both of these functions are executed by worker threads,
not the main named thread. This causes ASAN to report memory leaks like
the following one upon shutdown (as long as named is asked to produce
any XML output over its configured statistics channels during its
lifetime):
Direct leak of 968 byte(s) in 1 object(s) allocated from:
#0 0x7f677c249cd8 in __interceptor_calloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cc:153
#1 0x7f677bc1838f in xmlGetGlobalState (/usr/lib/libxml2.so.2+0xa838f)
The data mentioned in the above report is a libxml2 state structure
stored as thread-specific data. Such chunks of memory are automatically
released (by a destructor passed to pthread_key_create() by libxml2)
whenever a thread that allocated a given chunk exits. However, if
xmlCleanupThreads() is called by a given thread before it exits, the
destructor will not be invoked (due to xmlCleanupThreads() calling
pthread_key_delete()) and ASAN will report a memory leak. Thus,
xmlInitThreads() and xmlCleanupThreads() must not be called from worker
threads. Since xmlInitThreads() must be called on Windows in order for
libxml2 to work at all, move xmlInitThreads() and xmlCleanupThreads()
calls to the main named thread (which does not produce any XML output
itself) in order to prevent the memory leak from being reported by ASAN.
(cherry picked from commit b425b5d56e)
Loaded GeoIP2 databases are only released when named is shut down, but
not during server reconfiguration. This causes memory to be leaked
every time "rndc reconfig" or "rndc reload" is used, as long as any
GeoIP2 database is in use. Fix by releasing any loaded GeoIP2 databases
before reloading them. Do not call dns_geoip_shutdown() until server
shutdown as that function releases the memory context used for caching
GeoIP2 lookup results.
(cherry picked from commit 670afbe84a)
When loading the configuration fails, there might be already other tasks
running and calling OpenSSL library functions. The OpenSSL on_exit
handler is called when exiting the main process and there's a timing
race between the on_exit function that destroys OpenSSL allocated
resources (threads, locks, ...) and other tasks accessing the very same
resources leading to a crash in the system threading library. Therefore,
the fatal() function needs to request exlusive access to the task
manager to finish the already running tasks and exit only when no other
tasks are running.
(cherry picked from commit 952d7fde63)
Previously, there was no limit to the number of concurrently served
queries over one pipelined TCP connection; an unlimited number of
queries sent over a single TCP connection could have potentially
exhausted the server's resources.
This variable will report the maximum number of simultaneous tcp clients
that BIND has served while running.
It can be verified by running rndc status, then inspect "tcp high-water:
count", or by generating statistics file, rndc stats, then inspect the
line with "TCP connection high-water" text.
The tcp-highwater variable is atomically updated based on an existing
tcp-quota system handled in ns/client.c.
(cherry picked from commit 66fe8627de)
The named_g_defaultdnstap was never used as the dnstap requires
explicit configuration of the output file.
Related scan-build report:
./server.c:3476:14: warning: Value stored to 'dpath' during its initialization is never read
const char *dpath = named_g_defaultdnstap;
^~~~~ ~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
(cherry picked from commit 6decd14592)
Until now, the build process for BIND on Windows involved upgrading the
solution file to the version of Visual Studio used on the build host.
Unfortunately, the executable used for that (devenv.exe) is not part of
Visual Studio Build Tools and thus there is no clean way to make that
executable part of a Windows Server container.
Luckily, the solution upgrade process boils down to just adding XML tags
to Visual Studio project files and modifying certain XML attributes - in
files which we pregenerate anyway using win32utils/Configure. Thus,
extend win32utils/Configure with three new command line parameters that
enable it to mimic what "devenv.exe bind9.sln /upgrade" does. This
makes the devenv.exe build step redundant and thus facilitates building
BIND in Windows Server containers.
(cherry picked from commit 0476e8f1ac)
Make stderr fully buffered on Windows to improve named performance when
it is logging to stderr, which happens e.g. in system tests. Note that:
- line buffering (_IOLBF) is unavailable on Windows,
- fflush() is called anyway after each log message gets written to the
default stderr logging channels created by libisc.
(cherry picked from commit c72da3497d)
BIND system tests are run in a Cygwin environment. Apparently Cygwin
shell sets the SEM_NOGPFAULTERRORBOX bit in its process error mode which
is then inherited by all spawned child processes. This bit prevents the
Windows Error Reporting dialog from being displayed, which I assume is
part of an effort to contain memory handling errors triggered by Cygwin
binaries in the Cygwin environment. Unfortunately, this also prevents
automatic crash dump creation by Windows Error Reporting and Cygwin
itself does not handle memory errors in native Windows processes spawned
from a Cygwin shell.
Fix by clearing the SEM_NOGPFAULTERRORBOX bit inside named if it is
started in a Cygwin environment, thus overriding the Cygwin-set process
error mode in order to enable Windows Error Reporting to handle all
named crashes.
(cherry picked from commit 3d4b17806f)
When libxml2 is to be used in a multi-threaded application, the
xmlInitThreads() function must be called before any other libxml2
function. This function does different things on various platforms and
thus one can get away without calling it on Unix systems, but not on
Windows, where it initializes critical section objects used for
synchronizing access to data structures shared between threads. Add the
missing xmlInitThreads() call to prevent crashes on affected systems.
Also add a matching xmlCleanupThreads() call to properly release the
resources set up by xmlInitThreads().
(cherry picked from commit a3c0b00ef6)
Addresses the database changing w/o the changes being done under task lock.
Fix: build the database before assigning it to the zone.
(cherry picked from commit 4e686f40e0)
For some libc implementations, BUFSIZ is small enough (e.g. 1024 for
musl libc) to trigger compilation warnings about insufficient size of
certain buffers. Since the relevant buffers are used for printing DNS
names, increase their size to '(n + 1) * DNS_NAME_FORMATSIZE', where 'n'
is the number of DNS names which are printed to a given buffer. This
results in somewhat arbitrary, albeit nicely-aligned and large enough
buffer sizes.
(cherry picked from commit 3384455659)
Including <sys/errno.h> instead of <errno.h> raises a compiler warning
when building against musl libc. Always include <errno.h> instead of
<sys/errno.h> to prevent that compilation warning from being triggered
and to achieve consistency in this regard across the entire source tree.
(cherry picked from commit b5cd146033)
This commit changes the BIND cookie algorithms to match
draft-sury-toorop-dnsop-server-cookies-00. Namely, it changes the Client Cookie
algorithm to use SipHash 2-4, adds the new Server Cookie algorithm using SipHash
2-4. The change doesn't make the SipHash 2-4 to be the default algorithm, this
is up to the operator.
(cherry picked from commit 196b342bc9)
- revise mapping of search terms to database types to match the
GeoIP2 schemas.
- open GeoIP2 databases when starting up; close when shutting down.
- clarify the logged error message when an unknown database type
is configured.
- add new geoip ACL subtypes to support searching for continent in
country databases.
- map geoip ACL subtypes to specific MMDB database queries.
- perform MMDB lookups based on subtype, saving state between
queries so repeated lookups for the same address aren't necessary.
(cherry picked from commit 6e0b93e5a0)
(cherry picked from commit 0283ab7512)
- "--with-geoip" is used to enable the legacy GeoIP library.
- "--with-geoip2" is used to enable the new GeoIP2 library
(libmaxminddb), and is on by default if the library is found.
- using both "--with-geoip" and "--with-geoip2" at the same time
is an error.
- an attempt is made to determine the default GeoIP2 database path at
compile time if pkg-config is able to report the module prefix. if
this fails, it will be necessary to set the path in named.conf with
geoip-directory
- Makefiles have been updated, and a stub lib/dns/geoip2.c has been
added for the eventual GeoIP2 search implementation.
(cherry picked from commit fea6b5bf10)
(cherry picked from commit 6a7e805796)
In ISC-Bugs 45340, I wrote:
The Statistics channel offers links to Zones and Traffic.
Both produce valid data, but display as blank pages with
a web browser.
Zones never had XSL (I provided the original
implementation, but punted on the XSL).
Traffic has XSL, but it wasn't updated to reflect the
split between IPv4 and IPv6 data.
I've picked up enough XSL to fix my original omission,
and as penance for my sloth, fixed the Traffic bug as well.
(cherry picked from commit 96f0bbd4d5)
- when processing authoritative queries for ./NS, set 'gluedb' so
that glue will be included in the response, regardless of how
'minimal-responses' has been configured.
(cherry picked from commit e7684c7b64)
We increase recursclients when we attach to recursion quota,
decrease when we detach. In some cases, when we hit soft
quota, we might attach to quota without increasing recursclients
gauge. We then decrease the gauge when we detach from quota,
and it causes the statistics to underflow.
Fix makes sure that we increase recursclients always when we
succesfully attach to recursion quota.
Backport named command line switches implemented in commit
c81c9660f5 as they are needed by the
"legacy" system checks which are currently present in master and v9_14
branches, but missing in the v9_11 branch.
