since it is not necessary to find partial matches when looking
up names in a TSIG keyring, we can use a hash table instead of
an RBT to store them.
the tsigkey object now stores the key name as a dns_fixedname
rather than allocating memory for it.
the `name` parameter to dns_tsigkeyring_add() has been removed;
it was unneeded since the tsigkey object already contains a copy
of the name.
the opportunistic cleanup_ring() function has been removed;
it was only slowing down lookups.
this function was no longer needed, because the algorithm name is no
longer copied into the tsigkey object by dns_tsigkey_createfromkey();
it's always just a pointer to a statically defined name.
the prior practice of passing a dns_name containing the
expanded name of an algorithm to dns_tsigkey_create() and
dns_tsigkey_createfromkey() is unnecessarily cumbersome;
we can now pass the algorithm number instead.
use the ISC_REFCOUNT attach/detach implementation in dns/tsig.c
so that detailed tracing can be used during refactoring.
dns_tsig_keyring_t has been renamed dns_tsigkeyring_t so the type
and the attach/detach function names will match.
- style cleanups.
- simplify the function parameters to dns_tsigkey_create():
+ remove 'restored' and 'generated', they're only ever set to false.
+ remove 'creator' because it's only ever set to NULL.
+ remove 'inception' and 'expiry' because they're only ever set to
(0, 0) or (now, now), and either way, this means "never expire".
+ remove 'ring' because we can just use dns_tsigkeyring_add() instead.
- rename dns_keyring_restore() to dns_tsigkeyring_restore() to match the
rest of the functions operating on dns_tsigkeyring objects.
dns_view_find* may be called after the final call to dns_view_detach
is made which detaches view->zonetable to permit the server to
shutdown. We need to detect if view->zonetable is NULL during this
stage and appropriately recover.
Remove the code implementing nonstardard behaviors that were formerly
needed to allow GSS-TSIG to work with Windows 2000, which passed
End-of-Life in 2010.
Deprecate the "oldgsstsig" command and "-o" command line option
to nsupdate; these are now treated as synonyms for "gsstsig" and "-g"
respectively.
Development versions of cmocka require the intmax_t and uintmax_t types
to be defined by the time the test code includes the <cmocka.h> header.
These types are defined in the <stdint.h> header, which is included by
the <inttypes.h> header, which in turn is already explicitly included by
some of the programs in the tests/ directory. Ensure all programs in
that directory that include the <cmocka.h> header also include the
<inttypes.h> header to future-proof the code while keeping the change
set minimal and the resulting code consistent. Also prevent explicitly
including the <stdint.h> header in those programs as it is included by
the <inttypes.h> header.
Instead of having a global hashtable with a global rwlock for the GLUE
cache, move the glue_list directly into rdatasetheader and use
Userspace-RCU to update the pointer when the glue_list is empty.
Additionally, the cached glue_lists needs to be stored in the RBTDB
version for early cleaning, otherwise the circular dependencies between
nodes and glue_lists will prevent nodes to be ever cleaned up.
When liburcu is not installed from a system package, its headers are
not treated as system headers by the compiler, so BIND's -Werror and
other warning options take effect. The liburcu headers have a lot
of inline functions, some of which do not use all their arguments,
which BIND's build treats as an error.
When shutting down TCP sockets, the read callback calling logic was
flawed, it would call either one less callback or one extra. Fix the
logic in the way:
1. When isc_nm_read() has been called but isc_nm_read_stop() hasn't on
the handle, the read callback will be called with ISC_R_CANCELED to
cancel active reading from the socket/handle.
2. When isc_nm_read() has been called and isc_nm_read_stop() has been
called on the on the handle, the read callback will be called with
ISC_R_SHUTTINGDOWN to signal that the dormant (not-reading) socket
is being shut down.
3. The .reading and .recv_read flags are little bit tricky. The
.reading flag indicates if the outer layer is reading the data (that
would be uv_tcp_t for TCP and isc_nmsocket_t (TCP) for TLSStream),
the .recv_read flag indicates whether somebody is interested in the
data read from the socket.
Usually, you would expect that the .reading should be false when
.recv_read is false, but it gets even more tricky with TLSStream as
the TLS protocol might need to read from the socket even when sending
data.
Fix the usage of the .recv_read and .reading flags in the TLSStream
to their true meaning - which mostly consist of using .recv_read
everywhere and then wrapping isc_nm_read() and isc_nm_read_stop()
with the .reading flag.
4. The TLS failed read helper has been modified to resemble the TCP code
as much as possible, clearing and re-setting the .recv_read flag in
the TCP timeout code has been fixed and .recv_read is now cleared
when isc_nm_read_stop() has been called on the streaming socket.
5. The use of Network Manager in the named_controlconf, isccc_ccmsg, and
isc_httpd units have been greatly simplified due to the improved design.
6. More unit tests for TCP and TLS testing the shutdown conditions have
been added.
Co-authored-by: Ondřej Surý <ondrej@isc.org>
Co-authored-by: Artem Boldariev <artem@isc.org>
OpenSSL 3.1.0 uses __attribute__(malloc), conflicting with a redefined
malloc in cmocka.h.
As a workaround, include an OpenSSL header file before including
cmocka.h in the unit tests where OpenSSL is used.
It should be floor(DNS_NAME_MAXWIRE / 2) + 1 == 128
The mistake was introduced in c6bf51492d because:
* I was refactoring an existing `DNS_MAX_LABELS` defined as 127
* There was a longstanding bug in `dns_name_isvalid()` which
checked the number of labels against 127U instead of 128
* I mistakenly thought `dns_name_isvalid()` was correct and
`dns_name_countlabels()` was incorrect, but the reverse was true.
After this commit, occurrances of `DNS_NAME_MAXLABELS` with value
128 are consistent with the use of 127 or 128 before commit
c6bf51492d except for the mistake in `dns_name_isvalid()`.
This commit adds a test case that checks the MAXLABELS case
in `dns_name_fromtext()` and `dns_name_isvalid()`.
This change makes the zone table lock-free for reads. Previously, the
zone table used a red-black tree, which is not thread safe, so the hot
read path acquired both the per-view mutex and the per-zonetable
rwlock. (The double locking was to fix to cleanup races on shutdown.)
One visible difference is that zones are not necessarily shut down
promptly: it depends on when the qp-trie garbage collector cleans up
the zone table. The `catz` system test checks several times that zones
have been deleted; the test now checks for zones to be removed from
the server configuration, instead of being fully shut down. The catz
test does not churn through enough zones to trigger a gc, so the zones
are not fully detached until the server exits.
After this change, it is still possible to improve the way we handle
changes to the zone table, for instance, batching changes, or better
compaction heuristics.
Revert refcount debug tracing (commit a8b29f0365), there are better
ways to do it.
Use the dns_qpmethods_t typedef where appropriate.
Some stylistic improvements.
This is the first of the "fancy" searches that know how the DNS
namespace maps on to the structure of a qp-trie. For example, it will
find the closest enclosing zone in the zone tree.
The isc_time_now() and isc_time_now_hires() were used inconsistently
through the code - either with status check, or without status check,
or via TIME_NOW() macro with RUNTIME_CHECK() on failure.
Refactor the isc_time_now() and isc_time_now_hires() to always fail when
getting current time has failed, and return the isc_time_t value as
return value instead of passing the pointer to result in the argument.
The only place where dns_name_hash() was being used is the old hash
table in the dns_badcache unit. Squash the dns_name_fullhash() and
dns_name_hash() into single dns_name_hash() function that's always
case-insensitive as it doesn't make to do case-sensitive hashing of the
domain names and we were not using this anywhere.
This is a simple replacement using the semantic patch from the previous
commit and as added bonus, one removal of previously undetected unused
variable in named/server.c.
Instead of marking the unused entities with UNUSED(x) macro in the
function body, use a `ISC_ATTR_UNUSED` attribute macro that expans to
C23 [[maybe_unused]] or __attribute__((__unused__)) as fallback.
stop and restart the server in the 'tsiggss' test, in order
to confirm that GSS negotiated TSIG keys are saved and restored
when named loads.
added logging to dns_tsigkey_createfromkey() to indicate whether
a key has been statically configured, generated via GSS negotiation,
or restored from a file.
Completely remove the TKEY Mode 2 (Diffie-Hellman Exchanged Keying) from
BIND 9 (from named, named.conf and all the tools). The TKEY usage is
fringe at best and in all known cases, GSSAPI is being used as it should.
The draft-eastlake-dnsop-rfc2930bis-tkey specifies that:
4.2 Diffie-Hellman Exchanged Keying (Deprecated)
The use of this mode (#2) is NOT RECOMMENDED for the following two
reasons but the specification is still included in Appendix A in case
an implementation is needed for compatibility with old TKEY
implementations. See Section 4.6 on ECDH Exchanged Keying.
The mixing function used does not meet current cryptographic
standards because it uses MD5 [RFC6151].
RSA keys must be excessively long to achieve levels of security
required by current standards.
We might optionally implement Elliptic Curve Diffie-Hellman (ECDH) key
exchange mode 6 if the draft ever reaches the RFC status. Meanwhile the
insecure DH mode needs to be removed.
This implements node reference tracing that passes all the internal
layers from dns_db API (and friends) to increment_reference() and
decrement_reference().
It can be enabled by #defining DNS_DB_NODETRACE in <dns/trace.h> header.
The output then looks like this:
incr:node:check_address_records:rootns.c:409:0x7f67f5a55a40->references = 1
decr:node:check_address_records:rootns.c:449:0x7f67f5a55a40->references = 0
incr:nodelock:check_address_records:rootns.c:409:0x7f67f5a55a40:0x7f68304d7040->references = 1
decr:nodelock:check_address_records:rootns.c:449:0x7f67f5a55a40:0x7f68304d7040->references = 0
There's associated python script to find the missing detach located at:
https://gitlab.isc.org/isc-projects/bind9/-/snippets/1038
Add some qp-trie tracing macros which can be enabled by a
developer. These print a message when a leaf is attached or
detached, indicating which part of the qp-trie implementation
did so. The refcount methods must now return the refcount value
so it can be printed by the trace macros.
The first working multi-threaded qp-trie was stuck with an unpleasant
trade-off:
* Use `isc_rwlock`, which has acceptable write performance, but
terrible read scalability because the qp-trie made all accesses
through a single lock.
* Use `liburcu`, which has great read scalability, but terrible
write performance, because I was relying on `rcu_synchronize()`
which is rather slow. And `liburcu` is LGPL.
To get the best of both worlds, we need our own scalable read side,
which we now have with `isc_qsbr`. And we need to modify the write
side so that it is not blocked by readers.
Better write performance requires an async cleanup function like
`call_rcu()`, instead of the blocking `rcu_synchronize()`. (There
is no blocking cleanup in `isc_qsbr`, because I have concluded
that it would be an attractive nuisance.)
Until now, all my multithreading qp-trie designs have been based
around two versions, read-only and mutable. This is too few to
work with asynchronous cleanup. The bare minimum (as in epoch
based reclamation) is three, but it makes more sense to support an
arbitrary number. Doing multi-version support "properly" makes
fewer assumptions about how safe memory reclamation works, and it
makes snapshots and rollbacks simpler.
To avoid making the memory management even more complicated, I
have introduced a new kind of "packed reader node" to anchor the
root of a version of the trie. This is simpler because it re-uses
the existing chunk lifetime logic - see the discussion under
"packed reader nodes" in `qp_p.h`.
I have also made the chunk lifetime logic simpler. The idea of a
"generation" is gone; instead, chunks are either mutable or
immutable. And the QSBR phase number is used to indicate when a
chunk can be reclaimed.
Instead of the `shared_base` flag (which was basically a one-bit
reference count, with a two version limit) the base array now has a
refcount, which replaces the confusing ad-hoc lifetime logic with
something more familiar and systematic.
Randomized testing with intensive consistency and correctness checks
make it much easier to get good coverage and to shake out bugs than
hand-written unit tests for specific cases.
These tests only run in a single thread, but each test transaction
uses both a write/update and a query/snapshot, to ensure that
modifications are not visible to concurrent readers.
This change adds a number of support routines for the unit tests, and
for benchmarks and fuzz tests to be added later. It isn't necessary to
include the support routines in libdns, since they are not needed by
BIND's installed programs. So `libtest` seems like the best place for
them.
The tests themselves verify that dns_qpkey_fromname() behaves as
expected.
the 'dispatchmgr' member of the resolver object is used by both
the dns_resolver and dns_request modules, and may in the future
be used by others such as dns_xfrin. it doesn't make sense for it
to live in the resolver object; this commit moves it into dns_view.
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.
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.
DSCP has not been fully working since the network manager was
introduced in 9.16, and has been completely broken since 9.18.
This seems to have caused very few difficulties for anyone,
so we have now marked it as obsolete and removed the
implementation.
To ensure that old config files don't fail, the code to parse
dscp key-value pairs is still present, but a warning is logged
that the feature is obsolete and should not be used. Nothing is
done with configured values, and there is no longer any
range checking.
Additionally to renaming, it changes the function definition so that
it accepts a pointer to pointer instead of returning a pointer to the
new object.
It is mostly done to make it in line with other functions in the
module.
