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13268 commits

Author SHA1 Message Date
Matthijs Mekking
42f43cebdd Update dns_dnssec_syncdelete() function
Update the function that synchronizes the CDS and CDNSKEY DELETE
records. It now allows for the possibility that the CDS DELETE record
is published and the CDNSKEY DELETE record is not, and vice versa.

Also update the code in zone.c how 'dns_dnssec_syncdelete()' is called.

With KASP, we still maintain the DELETE records our self. Otherwise,
we publish the CDS and CDNSKEY DELETE record only if they are added
to the zone. We do still check if these records can be signed by a KSK.

This change will allow users to add a CDS and/or CDNSKEY DELETE record
manually, without BIND removing them on the next zone sign.

Note that this commit removes the check whether the key is a KSK, this
check is redundant because this check is also made in
'dst_key_is_signing()' when the role is set to DST_BOOL_KSK.

(cherry picked from commit 3d05c99abb)
2022-04-13 15:13:12 +02:00
Ondřej Surý
a7f893e836 Rename the configuration option to load balance sockets to reuseport
After some back and forth, it was decidede to match the configuration
option with unbound ("so-reuseport"), PowerDNS ("reuseport") and/or
nginx ("reuseport").

(cherry picked from commit 7e71c4d0cc)
2022-04-06 17:51:12 +02:00
Ondřej Surý
daa7d6d6db Revert "General cleanup of dns_rpz implementation"
This reverts commit 84e62cece5.
2022-04-06 10:41:49 +02:00
Ondřej Surý
f5fbe2c26f Revert "Refactor the dns_rpz_add/delete to use local rpz copy"
This reverts commit 635147d01a.
2022-04-06 10:41:39 +02:00
Ondřej Surý
b68ccdc48e Revert "Run the RPZ update as offloaded work"
This reverts commit 73a0bb8588.
2022-04-06 10:31:23 +02:00
Ondřej Surý
d836f23f79 Fix the Windows paths modified for load balanced sockets
When backporting the load balanced sockets to BIND 9.16, the Windows
specific paths were missed.  Add the #if(n)def _WIN32 back into the
appropriate places.
2022-04-05 11:53:18 +02:00
Ondřej Surý
5f27873d01 Rename shutdown() to test_shutdown() in timer_test.c
The shutdown() is part of standard library (POSIX-1), don't use such
name in the timer_test.c, but rather rename it to test_shutdown().
2022-04-05 02:17:47 +02:00
Ondřej Surý
9159837315 Enable the load-balance-sockets configuration
Previously, HAVE_SO_REUSEPORT_LB has been defined only in the private
netmgr-int.h header file, making the configuration of load balanced
sockets inoperable.

Move the missing HAVE_SO_REUSEPORT_LB define the isc/netmgr.h and add
missing isc_nm_getloadbalancesockets() implementation.

(cherry picked from commit 142c63dda8)
2022-04-05 02:17:47 +02:00
Ondřej Surý
8993ebc01a Add option to configure load balance sockets
Previously, the option to enable kernel load balancing of the sockets
was always enabled when supported by the operating system (SO_REUSEPORT
on Linux and SO_REUSEPORT_LB on FreeBSD).

It was reported that in scenarios where the networking threads are also
responsible for processing long-running tasks (like RPZ processing, CATZ
processing or large zone transfers), this could lead to intermitten
brownouts for some clients, because the thread assigned by the operating
system might be busy.  In such scenarious, the overall performance would
be better served by threads competing over the sockets because the idle
threads can pick up the incoming traffic.

Add new configuration option (`load-balance-sockets`) to allow enabling
or disabling the load balancing of the sockets.

(cherry picked from commit 85c6e797aa)
2022-04-05 01:21:50 +02:00
Ondřej Surý
73a0bb8588 Run the RPZ update as offloaded work
Previously, the RPZ updates ran quantized on the main nm_worker loops.
As the quantum was set to 1024, this might lead to service
interruptions when large RPZ update was processed.

Change the RPZ update process to run as the offloaded work.  The update
and cleanup loops were refactored to do as little locking of the
maintenance lock as possible for the shortest periods of time and the db
iterator is being paused for every iteration, so we don't hold the rbtdb
tree lock for prolonged periods of time.

(cherry picked from commit f106d0ed2b)
(cherry picked from commit e128b6a951)
2022-04-05 00:30:39 +02:00
Ondřej Surý
635147d01a Refactor the dns_rpz_add/delete to use local rpz copy
Previously dns_rpz_add() were passed dns_rpz_zones_t and index to .zones
array.  Because we actually attach to dns_rpz_zone_t, we should be using
the local pointer instead of passing the index and "finding" the
dns_rpz_zone_t again.

Additionally, dns_rpz_add() and dns_rpz_delete() were used only inside
rpz.c, so make them static.

(cherry picked from commit b6e885c97f)
(cherry picked from commit f4cba0784e)
2022-04-05 00:30:39 +02:00
Ondřej Surý
84e62cece5 General cleanup of dns_rpz implementation
Do a general cleanup of lib/dns/rpz.c style:

 * Removed deprecated and unused functions
 * Unified dns_rpz_zone_t naming to rpz
 * Unified dns_rpz_zones_t naming to rpzs
 * Add and use rpz_attach() and rpz_attach_rpzs() functions
 * Shuffled variables to be more local (cppcheck cleanup)

(cherry picked from commit 840179a247)
(cherry picked from commit bfee462403)
2022-04-05 00:02:35 +02:00
Mark Andrews
c284112bec Prevent arithmetic overflow of 'i' in master.c:generate
the value of 'i' in generate could overflow when adding 'step' to
it in the 'for' loop.  Use an unsigned int for 'i' which will give
an additional bit and prevent the overflow.  The inputs are both
less than 2^31 and and the result will be less than 2^32-1.

(cherry picked from commit 5abdee9004)
2022-04-01 21:42:53 +11:00
Tony Finch
a5d65815bc Log "not authoritative for update zone" more clearly
Ensure the update zone name is mentioned in the NOTAUTH error message
in the server log, so that it is easier to track down problematic
update clients. There are two cases: either the update zone is
unrelated to any of the server's zones (previously no zone was
mentioned); or the update zone is a subdomain of one or more of the
server's zones (previously the name of the irrelevant parent zone was
misleadingly logged).

Closes #3209

(cherry picked from commit 84c4eb02e7)
2022-03-30 13:24:56 +01:00
Ondřej Surý
79b7804ce8 Consistenly use UNREACHABLE() instead of ISC_UNREACHABLE()
In couple places, we have missed INSIST(0) or ISC_UNREACHABLE()
replacement on some branches with UNREACHABLE().  Replace all
ISC_UNREACHABLE() or INSIST(0) calls with UNREACHABLE().
2022-03-28 23:28:05 +02:00
Ondřej Surý
4d1d91d709 Add win32 __builtin_unreachable() shim
The backport of using modern compiler features broken Windows debug
build because there's no __builtin_unreachable() in MSVC.

Define __builtin_unreachable() shim on MSVC using __assume(0).
2022-03-28 12:57:42 +02:00
Tony Finch
aaa923845d More explicit dns64 prefix errors
Quote the dns64 prefix in error messages that complain about
problems with it, to avoid confusion with the following ACLs.

Closes #3210

(cherry picked from commit 496c02d32a)
2022-03-25 16:09:12 +01:00
Ondřej Surý
888dcc6aab Remove UNREACHABLE() statements after exit()
Couple of UNREACHABLE() statements following exit() were found and
removed.

(cherry picked from commit 81fdc4a822)
2022-03-25 10:08:39 +01:00
Ondřej Surý
8b1d60933c Remove workaround for ancient clang versions (<< 3.2 and << 4.0.1)
Some ancient versions of clang reported uninitialized memory use false
positive (see https://bugs.llvm.org/show_bug.cgi?id=14461).  Since clang
4.0.1 has been long obsoleted, just remove the workarounds.

(cherry picked from commit ae508c17bc)
2022-03-25 09:37:22 +01:00
Ondřej Surý
b624be2544 Remove use of the inline keyword used as suggestion to compiler
Historically, the inline keyword was a strong suggestion to the compiler
that it should inline the function marked inline.  As compilers became
better at optimising, this functionality has receded, and using inline
as a suggestion to inline a function is obsolete.  The compiler will
happily ignore it and inline something else entirely if it finds that's
a better optimisation.

Therefore, remove all the occurences of the inline keyword with static
functions inside single compilation unit and leave the decision whether
to inline a function or not entirely on the compiler

NOTE: We keep the usage the inline keyword when the purpose is to change
the linkage behaviour.

(cherry picked from commit 20f0936cf2)
2022-03-25 09:37:18 +01:00
Ondřej Surý
75f9dd8e82 Simplify way we tag unreachable code with only ISC_UNREACHABLE()
Previously, the unreachable code paths would have to be tagged with:

    INSIST(0);
    ISC_UNREACHABLE();

There was also older parts of the code that used comment annotation:

    /* NOTREACHED */

Unify the handling of unreachable code paths to just use:

    UNREACHABLE();

The UNREACHABLE() macro now asserts when reached and also uses
__builtin_unreachable(); when such builtin is available in the compiler.

(cherry picked from commit 584f0d7a7e)
2022-03-25 09:33:51 +01:00
Ondřej Surý
673e53f81d Add FALLTHROUGH macro for __attribute__((fallthrough))
Gcc 7+ and Clang 10+ have implemented __attribute__((fallthrough)) which
is explicit version of the /* FALLTHROUGH */ comment we are currently
using.

Add and apply FALLTHROUGH macro that uses the attribute if available,
but does nothing on older compilers.

In one case (lib/dns/zone.c), using the macro revealed that we were
using the /* FALLTHROUGH */ comment in wrong place, remove that comment.

(cherry picked from commit fe7ce629f4)
2022-03-25 09:30:16 +01:00
Tony Finch
afb5f59a6f Remove a redundant variable-length array
In the GSS-TSIG verification code there was an alarming
variable-length array whose size came off the network, from the
signature in the request. It turned out to be safe, because the caller
had previously checked that the signature had a reasonable size.
However, the safety checks are in the generic TSIG implementation, and
the risky VLA usage was in the GSS-specific code, and they are
separated by the DST indirection layer, so it wasn't immediately
obvious that the risky VLA was in fact safe.

In fact this risky VLA was completely unnecessary, because the GSS
signature can be verified in place without being copied to the stack,
like the message covered by the signature. The `REGION_TO_GBUFFER()`
macro backwardly assigns the region in its left argument to the GSS
buffer in its right argument; this is just a pointer and length
conversion, without copying any data. The `gss_verify_mic()` call uses
both message and signature GSS buffers in a read-only manner.
2022-03-18 17:21:57 +00:00
Ondřej Surý
2c86bd4ed9 Remove debugging implementation of stdatomic using mutexes
Upcoming LLVM/Clang 15 has marked the ATOMIC_VAR_INIT() as deprecated
breaking the build.  In the previous commit, we have removed the use of
ATOMIC_VAR_INIT(), but as that was a prerequisite to using the
--enable-mutexatomic debugging mode, we have to remove the debugging
mode.
2022-03-17 21:44:04 +01:00
Ondřej Surý
25732d818d Remove usage of deprecated ATOMIC_VAR_INIT() macro
The C17 standard deprecated ATOMIC_VAR_INIT() macro (see [1]).  Follow
the suite and remove the ATOMIC_VAR_INIT() usage in favor of simple
assignment of the value as this is what all supported stdatomic.h
implementations do anyway:

  * MacOSX.plaform: #define ATOMIC_VAR_INIT(__v) {__v}
  * Gcc stdatomic.h: #define ATOMIC_VAR_INIT(VALUE)	(VALUE)

1. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1138r0.pdf

(cherry picked from commit f251d69eba)
2022-03-17 21:44:04 +01:00
Ondřej Surý
821be88002 Change xfer-out timer message log level to DEBUG(1)
When max-transfer-*-out timeouts were reintroduced, the log message
about starting the timer was errorneously left as ISC_LOG_ERROR.
Change the log level of said message to ISC_LOG_DEBUG(1).

(cherry picked from commit 8f6e4dfa15)
2022-03-17 21:39:20 +01:00
Ondřej Surý
be47b2e5e4 Add couple missing braces around single-line statements
The clang-format-15 has new option InsertBraces that could add missing
branches around single line statements.  Use that to our advantage
without switching to not-yet-released LLVM version to add missing braces
in couple of places.
2022-03-17 18:31:36 +01:00
Ondřej Surý
7a386256b6 On shutdown, reset the established TCP connections
Previously, the established TCP connections (both client and server)
would be gracefully closed waiting for the write timeout.

Don't wait for TCP connections to gracefully shutdown, but directly
reset them for faster shutdown.

(cherry picked from commit 6ddac2d56d)
2022-03-17 16:07:52 +01:00
Ondřej Surý
d17d043499 Change single write timer to per-send timers
Previously, there was a single per-socket write timer that would get
restarted for every new write.  This turned out to be insufficient
because the other side could keep reseting the timer, and never reading
back the responses.

Change the single write timer to per-send timer which would in turn
reset the TCP connection on the first send timeout.

(cherry picked from commit a761aa59e3)
2022-03-17 16:07:52 +01:00
Ondřej Surý
afee2b5a7b Run .closehandle_cb asynchrounosly in nmhandle_detach_cb()
When sock->closehandle_cb is set, we need to run nmhandle_detach_cb()
asynchronously to ensure correct order of multiple packets processing in
the isc__nm_process_sock_buffer().  When not run asynchronously, it
would cause:

  a) out-of-order processing of the return codes from processbuffer();

  b) stack growth because the next TCP DNS message read callback will
     be called from within the current TCP DNS message read callback.

The sock->closehandle_cb is set to isc__nm_resume_processing() for TCP
sockets which calls isc__nm_process_sock_buffer().  If the read callback
(called from isc__nm_process_sock_buffer()->processbuffer()) doesn't
attach to the nmhandle (f.e. because it wants to drop the processing or
we send the response directly via uv_try_write()), the
isc__nm_resume_processing() (via .closehandle_cb) would call
isc__nm_process_sock_buffer() recursively.

The below shortened code path shows how the stack can grow:

 1: ns__client_request(handle, ...);
 2: isc_nm_tcpdns_sequential(handle);
 3: ns_query_start(client, handle);
 4:   query_lookup(qctx);
 5:     query_send(qctcx->client);
 6:       isc__nmhandle_detach(&client->reqhandle);
 7:         nmhandle_detach_cb(&handle);
 8:           sock->closehandle_cb(sock); // isc__nm_resume_processing
 9:             isc__nm_process_sock_buffer(sock);
10:               processbuffer(sock); // isc__nm_tcpdns_processbuffer
11:                 isc_nmhandle_attach(req->handle, &handle);
12:                 isc__nm_readcb(sock, req, ISC_R_SUCCESS);
13:                   isc__nm_async_readcb(NULL, ...);
14:                     uvreq->cb.recv(...); // ns__client_request

Instead, if 'sock->closehandle_cb' is set, we need to run detach the
handle asynchroniously in 'isc__nmhandle_detach', so that on line 8 in
the code flow above does not start this recursion. This ensures the
correct order when processing multiple packets in the function
'isc__nm_process_sock_buffer()' and prevents the stack growth.

When not run asynchronously, the out-of-order processing leaves the
first TCP socket open until all requests on the stream have been
processed.

If the pipelining is disabled on the TCP via `keep-response-order`
configuration option, named would keep the first socket in lingering
CLOSE_WAIT state when the client sends an incomplete packet and then
closes the connection from the client side.
2022-03-17 00:19:11 +01:00
Mark Andrews
71b2421054 Look for zones deeper than the current domain or forward name
When caching glue, we need to ensure that there is no closer
source of truth for the name. If the owner name for the glue
record would be answered by a locally configured zone, do not
cache.
2022-03-17 00:19:11 +01:00
Mark Andrews
ea06552a3d Check cached names for possible "forward only" clause
When caching additional and glue data *not* from a forwarder, we must
check that there is no "forward only" clause covering the owner name
that would take precedence.  Such names would normally be allowed by
baliwick rules, but a "forward only" zone introduces a new baliwick
scope.
2022-03-17 00:19:11 +01:00
Mark Andrews
3fc7accd88 Check that the forward declaration is unchanged and not overridden
If we are using a fowarder, in addition to checking that names to
be cached are subdomains of the forwarded namespace, we must also
check that there are no subsidiary forwarded namespaces which would
take precedence. To be safe, we don't cache any responses if the
forwarding configuration has changed since the query was sent.
2022-03-17 00:19:11 +01:00
Mark Andrews
24155213be Add additional name checks when using a forwarder
When using a forwarder, check that the owner name of response
records are within the bailiwick of the forwarded name space.
2022-03-17 00:19:11 +01:00
Ondřej Surý
e7fb7c1de5 Make isc_heap_create() and isc_heap_insert() return void
Previously, the function(s) in the commit subject could fail for various
reasons - mostly allocation failures, or other functions returning
different return code than ISC_R_SUCCESS.  Now, the aforementioned
function(s) cannot ever fail and they would always return ISC_R_SUCCESS.

Change the function(s) to return void and remove the extra checks in
the code that uses them.

(cherry picked from commit bbb4cdb92d)
2022-03-08 20:49:15 +01:00
Ondřej Surý
848e6ee7b6 Make dns_catz_get_iterator() return void
Previously, the function(s) in the commit subject could fail for various
reasons - mostly allocation failures, or other functions returning
different return code than ISC_R_SUCCESS.  Now, the aforementioned
function(s) cannot ever fail and they would always return ISC_R_SUCCESS.

Change the function(s) to return void and remove the extra checks in
the code that uses them.

(cherry picked from commit d128656d2e)
2022-03-08 20:20:54 +01:00
Ondřej Surý
ba89da052a Make isc_ht_init() and isc_ht_iter_create() return void
Previously, the function(s) in the commit subject could fail for various
reasons - mostly allocation failures, or other functions returning
different return code than ISC_R_SUCCESS.  Now, the aforementioned
function(s) cannot ever fail and they would always return ISC_R_SUCCESS.

Change the function(s) to return void and remove the extra checks in
the code that uses them.

(cherry picked from commit 8fa27365ec)
2022-03-08 20:20:52 +01:00
Mark Andrews
2c7f02ca45 Check dnssec-policy key roles for validity
For each algorithm there must be a key performing the KSK and
ZSK rolls.  After reading the keys from named.conf check that
each algorithm present has both rolls.  CSK implicitly has both
rolls.

(cherry picked from commit 9bcf45f4ce)
2022-03-08 21:56:39 +11:00
Aram Sargsyan
73e660a806 Use autoconf check for BN_GENCB_new()
BIND unconditionally uses shims for BN_GENCB_new(), BN_GENCB_free(),
and BN_GENCB_get_arg() for all LibreSSL versions and, correctly, for
OpenSSL <1.1.0 versions.

This breaks LibreSSL compilation starting with LibreSSL 3.5.0.

Use autoconf check instead to check whether the family of the functions
are available.

(cherry picked from commit 749973f3259b7638a6af02b7da2f40ae28bdd402)
2022-03-02 09:34:29 +00:00
Aram Sargsyan
2325ed66c5 Remove EVP_CIPHER_CTX_new() and EVP_CIPHER_CTX_free() shims
LibreSSL 3.5.0 fails to compile with these shims. We could have just
removed the LibreSSL check from the pre-processor condition, but it
seems that these shims are no longer needed because all the supported
versions of OpenSSL and LibreSSL have those functions.

According to EVP_ENCRYPTINIT(3) manual page in LibreSSL,
EVP_CIPHER_CTX_new() and EVP_CIPHER_CTX_free() first appeared in
OpenSSL 0.9.8b, and have been available since OpenBSD 4.5.

(cherry picked from commit a3789053682b57a2031de8c544134f1923e76cf3)
2022-03-02 09:31:50 +00:00
Mark Andrews
0b6af23d61 Grow the lex token buffer in one more place
when parsing key pairs, if the '=' character fell at max_token
a protective INSIST preventing buffer overrun could be triggered.
Attempt to grow the buffer immediately before the INSIST.

Also removed an unnecessary INSIST on the opening double quote
of key buffer pair.

(cherry picked from commit 4c356d2770)
2022-03-02 01:04:40 +00:00
Mark Andrews
a247d282bf Use unsigned arithmetic when shifting by 24
By default C promotes short unsigned values to signed int which
leads to undefined behaviour when the value is shifted by too much.
Force unsigned arithmetic to be perform by explicitly casting to a
unsigned type.

(cherry picked from commit b8b99603f1)
2022-03-02 11:06:53 +11:00
Ondřej Surý
ac5952aee8 Handle TCP sockets in isc__nmsocket_reset()
The isc__nmsocket_reset() was missing a case for raw TCP sockets (used
by RNDC and DoH) which would case a assertion failure when write timeout
would be triggered.

TCP sockets are now also properly handled in isc__nmsocket_reset().

(cherry picked from commit b220fb32bd)
2022-02-28 11:44:47 +01:00
Ondřej Surý
fe5cd40a3a Disable inactive uvreqs caching when compiled with sanitizers
When isc__nm_uvreq_t gets deactivated, it could be just put onto array
stack to be reused later to save some initialization time.
Unfortunately, this might hide some use-after-free errors.

Disable the inactive uvreqs caching when compiled with Address or
Thread Sanitizer.

(cherry picked from commit be339b3c83)
2022-02-24 00:16:31 +01:00
Ondřej Surý
55780afdb9 Disable inactive handles caching when compiled with sanitizers
When isc_nmhandle_t gets deactivated, it could be just put onto array
stack to be reused later to safe some initialization time.
Unfortunately, this might hide some use-after-free errors.

Disable the inactive handles caching when compiled with Address or
Thread Sanitizer.

(cherry picked from commit 92cce1da65)
2022-02-24 00:10:18 +01:00
Ondřej Surý
7765263e68 Remove active handles tracking from isc__nmsocket_t
The isc__nmsocket_t has locked array of isc_nmhandle_t that's not used
for anything.  The isc__nmhandle_get() adds the isc_nmhandle_t to the
locked array (and resized if necessary) and removed when
isc_nmhandle_put() finally destroys the handle.  That's all it does, so
it serves no useful purpose.

Remove the .ah_handles, .ah_size, and .ah_frees members of the
isc__nmsocket_t and .ah_pos member of the isc_nmhandle_t struct.

(cherry picked from commit e2555a306f)
2022-02-23 23:50:54 +01:00
Ondřej Surý
7b8e265a40 Delay isc__nm_uvreq_t deallocation to connection callback
When the TCP, TCPDNS or TLSDNS connection times out, the isc__nm_uvreq_t
would be pushed into sock->inactivereqs before the uv_tcp_connect()
callback finishes.  Because the isc__nmsocket_t keeps the list of
inactive isc__nm_uvreq_t, this would cause use-after-free only when the
sock->inactivereqs is full (which could never happen because the failure
happens in connection timeout callback) or when the sock->inactivereqs
mechanism is completely removed (f.e. when running under Address or
Thread Sanitizer).

Delay isc__nm_uvreq_t deallocation to the connection callback and only
signal the connection callback should be called by shutting down the
libuv socket from the connection timeout callback.

(cherry picked from commit 3268627916)
2022-02-23 23:36:09 +01:00
Ondřej Surý
af2bddc242 Properly free up enqueued netievents in nm_destroy()
When the isc_netmgr is being destroyed, the normal and priority queues
should be dequeued and netievents properly freed.  This wasn't the case.

(cherry picked from commit 88418c3372)
2022-02-23 22:53:41 +01:00
Michał Kępień
60e82835ec Fix more ns_statscounter_recursclients underflows
Commit aab691d512 did not fix all possible
scenarios in which the ns_statscounter_recursclients counter underflows.
The solution implemented therein can be ineffective e.g. when CNAME
chaining happens with prefetching enabled.

Here is an example recursive resolution scenario in which the
ns_statscounter_recursclients counter can underflow with the current
logic in effect:

 1. Query processing starts, the answer is not found in the cache, so
    recursion is started.  The NS_CLIENTATTR_RECURSING attribute is set.
    ns_statscounter_recursclients is incremented (Δ = +1).

 2. Recursion completes, returning a CNAME.  client->recursionquota is
    non-NULL, so the NS_CLIENTATTR_RECURSING attribute remains set.
    ns_statscounter_recursclients is decremented (Δ = 0).

 3. Query processing restarts.

 4. The current QNAME (the target of the CNAME from step 2) is found in
    the cache, with a TTL low enough to trigger a prefetch.

 5. query_prefetch() attaches to client->recursionquota.
    ns_statscounter_recursclients is not incremented because
    query_prefetch() does not do that (Δ = 0).

 6. Query processing restarts.

 7. The current QNAME (the target of the CNAME from step 4) is not found
    in the cache, so recursion is started.  client->recursionquota is
    already attached to (since step 5) and the NS_CLIENTATTR_RECURSING
    attribute is set (since step 1), so ns_statscounter_recursclients is
    not incremented (Δ = 0).

 8. The prefetch from step 5 completes.  client->recursionquota is
    detached from in prefetch_done().  ns_statscounter_recursclients is
    not decremented because prefetch_done() does not do that (Δ = 0).

 9. Recursion for the current QNAME completes.  client->recursionquota
    is already detached from, i.e. set to NULL (since step 8), and the
    NS_CLIENTATTR_RECURSING attribute is set (since step 1), so
    ns_statscounter_recursclients is decremented (Δ = -1).

Another possible scenario is that after step 7, recursion for the target
of the CNAME from step 4 completes before the prefetch for the CNAME
itself.  fetch_callback() then notices that client->recursionquota is
non-NULL and decrements ns_statscounter_recursclients, even though
client->recursionquota was attached to by query_prefetch() and therefore
not accompanied by an incrementation of ns_statscounter_recursclients.
The net result is also an underflow.

Instead of trying to properly handle all possible orderings of events
set into motion by normal recursion and prefetch-triggered recursion,
adjust ns_statscounter_recursclients whenever the recursive clients
quota is successfully attached to or detached from.  Remove the
NS_CLIENTATTR_RECURSING attribute altogether as its only purpose is made
obsolete by this change.

(cherry picked from commit f7482b68b9)
2022-02-23 14:45:06 +01:00
Ondřej Surý
cbf2bed95e Reimplement the max-transfer-time-out and max-transfer-idle-out
While refactoring the libns to use the new network manager, the
max-transfer-*-out options were not implemented and they were turned
non-operational.

Reimplement the max-transfer-idle-out functionality using the write
timer and max-transfer-time-out using the new isc_nm_timer API.

(cherry picked from commit 8643bbab84)
2022-02-17 22:59:24 +01:00