When "rndc reconfig" is run, named first configures a fresh set of views
and then tears down the old views. Consider what happens for a single
view with LMDB enabled; "envA" is the pointer to the LMDB environment
used by the original/old version of the view, "envB" is the pointer to
the same LMDB environment used by the new version of that view:
1. mdb_env_open(envA) is called when the view is first created.
2. "rndc reconfig" is called.
3. mdb_env_open(envB) is called for the new instance of the view.
4. mdb_env_close(envA) is called for the old instance of the view.
This seems to have worked so far. However, an upstream change [1] in
LMDB which will be part of its 0.9.26 release prevents the above
sequence of calls from working as intended because the locktable mutexes
will now get destroyed by the mdb_env_close() call in step 4 above,
causing any subsequent mdb_txn_begin() calls to fail (because all of the
above steps are happening within a single named process).
Preventing the above scenario from happening would require either
redesigning the way we use LMDB in BIND, which is not something we can
easily backport, or redesigning the way BIND carries out its
reconfiguration process, which would be an even more severe change.
To work around the problem, set MDB_NOLOCK when calling mdb_env_open()
to stop LMDB from controlling concurrent access to the database and do
the necessary locking in named instead. Reuse the view->new_zone_lock
mutex for this purpose to prevent the need for modifying struct dns_view
(which would necessitate library API version bumps). Drop use of
MDB_NOTLS as it is made redundant by MDB_NOLOCK: MDB_NOTLS only affects
where LMDB reader locktable slots are stored while MDB_NOLOCK prevents
the reader locktable from being used altogether.
[1] https://git.openldap.org/openldap/openldap/-/commit/2fd44e325195ae81664eb5dc36e7d265927c5ebc
(cherry picked from commit 53120279b5)
Make yaml.load_all() use yaml.SafeLoader to address a warning currently
emitted when bin/tests/system/dnstap/ydump.py is run:
ydump.py:28: YAMLLoadWarning: calling yaml.load_all() without Loader=... is deprecated, as the default Loader is unsafe. Please read https://msg.pyyaml.org/load for full details.
for l in yaml.load_all(f.stdout):
(cherry picked from commit 62f631f798)
The "krb5-devel" package on openSUSE Tumbleweed installs the
"krb5-config" binary into a custom prefix, which prevents BIND's
"configure" script from autodetecting it. Fix by specifying the path to
the "krb5-config" binary using --with-gssapi.
(cherry picked from commit 1be15f5900)
Add a note why we don't have a test case for the issue.
It is tricky to write a good test case for this if our tools are
not allowed to create signatures for unsupported algorithms.
(cherry picked from commit c6345fffe9)
Assign and then check node for NULL to address another thread
changing radix->head in the meantime.
Move 'node != NULL' check into while loop test to silence cppcheck
false positive.
Fix pointer != NULL style.
(cherry picked from commit 51f08d2095)
enough buffer space. Also change named_os_uname() prototype so
that it is now returning (const char *) rather than (char *). If
uname() is not supported on a UNIX build prepopulate unamebuf[]
with "unknown architecture".
(cherry picked from commit 4bc3de070f)
Mark Andrews
Michał Kępień
Ondřej Surý
Witold KręcickiandOndřej Surý
Michal NowakandMichał Kępień
Evan Hunt
Matthijs MekkingandMark Andrews
Tinderbox UserandMichał Kępień