refactor validator so that the validation status object (previously
called dns_valstatus_t, which was derived from dns_validatorevent_t), is
now part of the dns_validator object. when calling validator callbacks,
the validator itself is now sent as the argument.
(note: this necessitates caution in the callback functions that are
internal to validator.c validators spawn other validators, and it can be
confusing at times whether we need to be looking at val, val->subvalidator,
or val->parent.)
There was a code flow error that would remove the expired ADB entry from
the LRU list and then a check in the expire_entry() would cause
assertion error because it expect the ADB entry to be linked.
Additionally, the expire mechanism would loop for cases when we would
held only a read rwlock; in such case we need to upgrade the lock and
try again, not just try again.
as there is no further use of isc_task in BIND, this commit removes
it, along with isc_taskmgr, isc_event, and all other related types.
functions that accepted taskmgr as a parameter have been cleaned up.
as a result of this change, some functions can no longer fail, so
they've been changed to type void, and their callers have been
updated accordingly.
the tasks table has been removed from the statistics channel and
the stats version has been updated. dns_dyndbctx has been changed
to reference the loopmgr instead of taskmgr, and DNS_DYNDB_VERSION
has been udpated as well.
change functions using isc_taskmgr_beginexclusive() to use
isc_loopmgr_pause() instead.
also, removed an unnecessary use of exclusive mode in
named_server_tcptimeouts().
most functions that were implemented as task events because they needed
to be running in a task to use exclusive mode have now been changed
into loop callbacks instead. (the exception is catz, which is being
changed in a separate commit because it's a particularly complex change.)
callback events from dns_resolver_createfetch() are now posted
using isc_async_run.
other modules which called the resolver and maintained task/taskmgr
objects for this purpose have been cleaned up.
The callbacks from dns_abd_createfind() are now posted using
isc_async_run() instead of isc_task_send(). ADB event types
have been replaced with a new dns_adbstatus_t type which is
included as find->status.
(The ADB still uses a task for dns_resolver_createfetch().)
dns_request_create() and _createraw() now take a 'loop' parameter
and run the callback event on the specified loop.
as the task manager is no longer used, it has been removed from
the dns_requestmgr structure. the dns_resolver_taskmgr() function
is also no longer used and has been removed.
Replace the isc_mutex in the dns_adb unit with isc_rwlock for better
performance. Both ADB names and ADB entries hashtables and LRU are now
using isc_rwlock.
This changes the internal isc_rwlock implementation to:
Irina Calciu, Dave Dice, Yossi Lev, Victor Luchangco, Virendra
J. Marathe, and Nir Shavit. 2013. NUMA-aware reader-writer locks.
SIGPLAN Not. 48, 8 (August 2013), 157–166.
DOI:https://doi.org/10.1145/2517327.24425
(The full article available from:
http://mcg.cs.tau.ac.il/papers/ppopp2013-rwlocks.pdf)
The implementation is based on the The Writer-Preference Lock (C-RW-WP)
variant (see the 3.4 section of the paper for the rationale).
The implemented algorithm has been modified for simplicity and for usage
patterns in rbtdb.c.
The changes compared to the original algorithm:
* We haven't implemented the cohort locks because that would require a
knowledge of NUMA nodes, instead a simple atomic_bool is used as
synchronization point for writer lock.
* The per-thread reader counters are not being used - this would
require the internal thread id (isc_tid_v) to be always initialized,
even in the utilities; the change has a slight performance penalty,
so we might revisit this change in the future. However, this change
also saves a lot of memory, because cache-line aligned counters were
used, so on 32-core machine, the rwlock would be 4096+ bytes big.
* The readers use a writer_barrier that will raise after a while when
readers lock can't be acquired to prevent readers starvation.
* Separate ingress and egress readers counters queues to reduce both
inter and intra-thread contention.
The dns_badcache was pulling the <isc/atomic.h> header only indirectly
via <isc/rwlock.h>, add the direct include as the <isc/rwlock.h> no
longer pulls the header when pthread_rwlock is used.
I misunderstood the purpose of the `heap_index` rdataset header
member; I thought it identified which heap to use, and could therefore
be smaller, the same size as `locknum` indexes. But in fact it is a
position within a heap, so it needs to be able to count up to the
total number of rdatasets in the rbtdb.
So this changes `heap_index` from `uint16_t` back to `unsigned int`.
To avoid re-embiggening the rdatasetheader, shrink the `count` member
from `uint32` to `uint16`. The `count` is used to rotate RRsets in
`dns_rdataset_towiresorted()`, so 16 bits is more than large enough.
This change also means we no longer need to avoid colliding with
`DNS_RDATASET_COUNT_UNDEFINED` i.e. UINT32_MAX.
Closes#3862
Unfortunately, C still lacks a standard function for pause (x86,
sparc) or yeild (arm) instructions, for use in spin lock or CAS loops.
BIND has its own based on vendor intrinsics or inline asm.
Previously, it was buried in the `isc_rwlock` implementation. This
commit renames `isc_rwlock_pause()` to `isc_pause()` and moves
it into <isc/pause.h>.
This commit also fixes the configure script so that it detects ARM
yield support on systems that identify as `aarch*` instead of `arm*`.
On 64-bit ARM systems we now use the ISB (instruction synchronization
barrier) instruction in preference to yield. The ISB instruction
pauses the CPU for longer, several nanoseconds, which is more like the
x86 pause instruction. There are more details in a Rust pull request,
which also refers to MySQL making the same change:
https://github.com/rust-lang/rust/pull/84725
A dns_rpz_unref_rpzs() call is missing when taking the 'goto unlock;'
path on shutdown, in order to compensate for the earlier
dns_rpz_ref_rpzs() call.
Move the dns_rpz_ref_rpzs() call after the shutdown check.
When there are multiple managed trust anchors we need to know the
name of the trust anchor that is failing. Extend the error message
to include the trust anchor name.
removed some functions that are no longer used and unlikely to
be resurrected, and also some that were only used to support Windows
and can now be replaced with generic versions.
Add magic value to the fctxcount, to check for completely invalid
counters, or counters that have been already destroyed.
Improve the locking around the counters, and because of that we can drop
the atomics and use simple integers - the counters were already locked
and the tiny bits that used the atomics were not worth the extra effort.
- removed documentation of -S option from named man page
- removed documentation of reserved-sockets from ARM
- simplified documentation of dnssec-secure-to-insecure - it
now just says it's obsolete rather than describing what it
doesn't do anymore
- marked three formerly obsolete options as ancient:
parent-registration-delay, reserved-sockets, and
suppress-initial-notify
isc_bind9 was a global bool used to indicate whether the library
was being used internally by BIND or by an external caller. external
use is no longer supported, but the variable was retained for use
by dyndb, which needed it only when being built without libtool.
building without libtool is *also* no longer supported, so the variable
can go away.
libuv support for receiving multiple UDP messages in a single system
call (recvmmsg()) has been tweaked several times between libuv versions
1.35.0 and 1.40.0. Mixing and matching libuv versions within that span
may lead to assertion failures and is therefore considered harmful, so
try to limit potential damage be preventing users from mixing libuv
versions with distinct sets of recvmmsg()-related flags.
The implementation of UDP recvmmsg in libuv 1.35 and 1.36 is
incomplete and could cause assertion failure under certain
circumstances.
Modify the configure and runtime checks to report a fatal error when
trying to compile or run with the affected versions.
Instead of using an extra rarely-used paramater to dns_clientinfo_init()
to set ECS information for a client, this commit adds a function
dns_clientinfo_setecs() which can be called only when ECS is needed.
A recent refactoring in 7e4e125e5e
had introduced a logical error which could result in calling the
dns_resolver_createfetch() function with 'nameservers' pointer set
to NULL, but with 'domain' not set to NULL, which is not allowed
by the function.
Make sure 'domain' is set only when 'nsrdataset' is valid.
the optional 'port' option, when used with notify-source,
transfer-source, etc, is used to set up UDP dispatches with a
particular source port, but when the actual UDP connection was
established the port would be overridden with a random one. this
has been fixed.
(configuring source ports is deprecated in 9.20 and slated for
removal in 9.22, but should still work correctly until then.)
the built-in trust anchors in named and delv are sufficent for
validation. named still needs to be able to load trust anchors from
a bind.keys file for testing purposes, but it doesn't need to be
the default behavior.
we now only load trust anchors from a file if explicitly specified
via the "bindkeys-file" option in named or the "-a" command line
argument to delv. documentation has been cleaned up to remove references
to /etc/bind.keys.
Closes#3850.
it was possible for a managed trust anchor needing to send a key
refresh query to be unable to do so because an authoritative zone
was not yet loaded. this has been corrected by delaying the
synchronization of managed-keys zones until after all zones are
loaded.
