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.
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.
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.
Commit b6d40b3c4e removed most uses of the
'fctx' variable from the rctx_dispfail() function: it is now only needed
by the FCTXTRACE3() macro. However, when --enable-querytrace is not in
effect, that macro evaluates to a list of UNUSED() macros that does not
include "UNUSED(fctx);". This triggers the following compilation
warning when building without --enable-querytrace:
resolver.c: In function 'rctx_dispfail':
resolver.c:7888:21: warning: unused variable 'fctx' [-Wunused-variable]
7888 | fetchctx_t *fctx = rctx->fctx;
| ^~~~
Fix by adding "UNUSED(fctx);" lines to all FCTXTRACE*() macros. This is
safe to do because all of those macros use the 'fctx' local variable, so
there is no danger of introducing new errors caused by use of undeclared
identifiers.
The keep-response-order option has been obsoleted, and in this commit,
remove the keep-response-order ACL map rendering the option no-op, the
call the isc_nm_sequential() and the now unused isc_nm_sequential()
function itself.
The keep-response-order option has been introduced when TCP pipelining
has been introduced to BIND 9 as a failsafe for possibly non-compliant
clients.
Declare the keep-response-order obsolete as all DNS clients should
either support out-of-order processing or don't send more DNS queries
until the DNS response for the previous one has been received.
There was an artificial limit of 23 on the number of simultaneous
pipelined queries in the single TCP connection. The new network
managers is capable of handling "unlimited" (limited only by the TCP
read buffer size ) queries similar to "unlimited" handling of the DNS
queries receive over UDP.
Don't limit the number of TCP queries that we can process within a
single TCP read callback.
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.
While refactoring the lib/ns/xfrout.c, it was discovered that .shutdown
and .shutdown_arg members of ns_client_t structure are unused.
Remove the unused members and associated code that was using in it in
the ns_xfrout.
When invalid DNS message is received, there was a handling mechanism for
DoH that would be called to return proper HTTP response.
Reuse this mechanism and reset the TCP connection when the client is
blackholed, DNS message is completely bogus or the ns_client receives
response instead of query.
- certain TCP result codes, including ISC_R_EOF and
ISC_R_CONNECTIONRESET, were being mapped to ISC_R_SHUTTINGDOWN
before calling the response handler in tcp_recv_cancelall().
the result codes should be passed through to the response handler
without being changed.
- the response handlers, resquery_response() and req_response(), had
code to return immediately if encountering ISC_R_EOF, but this is
not the correct behavior; that should only happen in the case of
ISC_R_CANCELED when it was the caller that canceled the operation
- ISC_R_CONNECTIONRESET was not being caught in rctx_dispfail().
- removed code in rctx_dispfail() to retry queries without EDNS
when receiving ISC_R_EOF; this is now treated the same as any
other connection failure.
Use the isc_nmhandle_setwritetimeout() function in the netmgr unit test
to allow more time for writing and reading the responses because some of
the intervals that are used in the unit tests are really small leaving a
little room for any delays.
In some situations (unit test and forthcoming XFR timeouts MR), we need
to modify the write timeout independently of the read timeout. Add a
isc_nmhandle_setwritetimeout() function that could be called before
isc_nm_send() to specify a custom write timeout interval.
When the outgoing TCP write buffers are full because the other party is
not reading the data, the uv_write() could wait indefinitely on the
uv_loop and never calling the callback. Add a new write timer that uses
the `tcp-idle-timeout` value to interrupt the TCP connection when we are
not able to send data for defined period of time.
The uv_tcp_close_reset() function was added in libuv 1.32.0 and since we
support older libuv releases, we have to add a shim uv_tcp_close_reset()
implementation loosely based on libuv.
Before adding the write timer, we have to remove the generic sock->timer
to sock->read_timer. We don't touch the function names to limit the
impact of the refactoring.
There was a bug in the checking of the "blackhole" ACL in
dns_request_create*(), causing an address to be treated as included
in the ACL if it was explicitly *excluded*. Thus, leaving "blackhole"
unset had no effect, but setting it to "none" would cause any
destination addresses to be rejected for dns_request purposes. This
would cause zone transfer requests and SOA queries to fail, among
other things.
The bug has been fixed, and "blackhole { none; };" was added to the
xfer system test as a regression test.
When a resolver priming attempt completes, the following message is
currently logged:
resolver priming query complete
This message is identical for both successful and failed priming
attempts. Consider the following log excerpts:
- successful priming attempt:
10-Feb-2022 11:33:11.272 all zones loaded
10-Feb-2022 11:33:11.272 running
10-Feb-2022 11:33:19.722 resolver priming query complete
- failed priming attempt:
10-Feb-2022 11:33:29.978 all zones loaded
10-Feb-2022 11:33:29.978 running
10-Feb-2022 11:33:38.432 timed out resolving '_.org/A/IN': 2001:500:9f::42#53
10-Feb-2022 11:33:38.522 timed out resolving './NS/IN': 2001:500:9f::42#53
10-Feb-2022 11:33:42.132 timed out resolving '_.org/A/IN': 2001:500:12::d0d#53
10-Feb-2022 11:33:42.285 timed out resolving './NS/IN': 2001:500:12::d0d#53
10-Feb-2022 11:33:44.685 resolver priming query complete
Include the result of each priming attempt in the relevant log message
to give the administrator better insight into named's resolver priming
process.
When libuv functions fail, they return correct return value that could
be useful for more detailed debugging. Currently, we usually just check
whether the return value is 0 and invoke assertion error if it doesn't
throwing away the details why the call has failed. Unfortunately, this
often happen on more exotic platforms.
Add a UV_RUNTIME_CHECK() macro that can be used to print more detailed
error message (via uv_strerror() before ending the execution of the
program abruptly with the assertion.
The task exclusive mode stops all processing (tasks and networking IO)
except the designated exclusive task events. This has impact on the
operation of the server. Add log messages indicating when we start the
exclusive mode, and when we end exclusive task mode.
There are reported occurences where the statitic counters underflows and
starts reporting non-sense.
Add a check for the underflow, when ``named`` is compiled in the
developer mode.
The isc_thread_setaffinity call was removed in !5265 and we are not
going to restore it because it was proven that the performance is better
without it. Additionally, remove the already disabled cpu system test.
The isc_thread_setconcurrency function is unused and also calling
pthread_setconcurrency() on Linux has no meaning, formerly it was
added because of Solaris in 2001 and it was removed when taskmgr was
refactored to run on top of netmgr in !4918.
When isc_quota_attach_cb() API returns ISC_R_QUOTA (meaning hard quota
was reached) the accept_connection() would return without logging a
message about quota reached.
Change the connection callback to log the quota reached message.
this brings DNS_CLIENTINFO_VERSION into line with the subscription
branch so that fixes applied to clientinfo processing can also be
applied to the main branch without diverging.
IBM power architecture has L1 cache line size equal to 128. Take
advantage of that on that architecture, do not force more common value
of 64. When it is possible to detect higher value, use that value
instead. Keep the default to be 64.
TLS clients can have their clock a short time in the past which will
result in not being able to validate the certificate.
Setting the "not before" property 5 minutes in the past will
accommodate with some possible clock skew across systems.
dns_dlzcreate() fails to free the memory allocated for dlzname
when an error occurs.
Free dlzname's memory (acquired earlier with isc_mem_strdup())
by calling isc_mem_free() before returning an error code.
When a zone is being configured with a new view, the catalog zones
structure will also be linked to that view. Later on, in case of some
error, should the zone be reverted to the previous view, the link
between the catalog zones structure and the view won't be reverted.
Change the dns_zone_setviewrevert() function so it calls
dns_zone_catz_enable() during a zone revert, which will reset the
link between `catzs` and view.
Separate the locked parts of dns_zone_catz_enable() and
dns_zone_catz_disable() functions into static functions. This will
let us perform those tasks from the other parts of the module while
the zone is locked, avoiding one pair of additional unlocking and
locking operations.
On some systems, the glibc can return 0 instead of cache-line size to
indicate the cache line sizes cannot be determined. This is comment
from glibc source code:
/* In general we cannot determine these values. Therefore we
return zero which indicates that no information is
available. */
As the goal of the check is to determine whether the L1 cache line size
is still 64 and we would use this value in case the sysconf() call is
not available, we can also ignore the invalid values returned by the
sysconf() call.
Some operating systems (OpenBSD and DragonFly BSD) don't restrict the
IPv6 sockets to sending and receiving IPv6 packets only. Explicitly
enable the IPV6_V6ONLY socket option on the IPv6 sockets to prevent
failures from using the IPv4-mapped IPv6 address.
The server_send_error_response() function is supposed to be used only
in case of failures and never in case of legitimate requests. Ensure
that ISC_HTTP_ERROR_SUCCESS is never passed there by mistake.
Previously, the netmgr/udp.c tried to detect the recvmmsg detection in
libuv with #ifdef UV_UDP_<foo> preprocessor macros. However, because
the UV_UDP_<foo> are not preprocessor macros, but enum members, the
detection didn't work. Because the detection didn't work, the code
didn't have access to the information when we received the final chunk
of the recvmmsg and tried to free the uvbuf every time. Fortunately,
the isc__nm_free_uvbuf() had a kludge that detected attempt to free in
the middle of the receive buffer, so the code worked.
However, libuv 1.37.0 changed the way the recvmmsg was enabled from
implicit to explicit, and we checked for yet another enum member
presence with preprocessor macro, so in fact libuv recvmmsg support was
never enabled with libuv >= 1.37.0.
This commit changes to the preprocessor macros to autoconf checks for
declaration, so the detection now works again. On top of that, it's now
possible to cleanup the alloc_cb and free_uvbuf functions because now,
the information whether we can or cannot free the buffer is available to
us.
When the named is shutting down, the zone event callbacks could
re-schedule the stub and refresh events leading to assertion failure.
Handle the ISC_R_SHUTTINGDOWN event state gracefully by bailing out.
In 2000, old BIND instances (BIND 8?) would return FORMERR if the SOA is
included in the NOTIFY.
Remove the workaround that detected the state and resent the NOTIFY
without SOA record.
Clients can cache the TLS certificates and refuse to accept
another one with the same serial number from the same issuer.
Generate a random serial number for the self-signed certificates
instead of using a fixed value.
GnuTLS, NSS, and possibly other TLS libraries currently fail to work
with compressed point conversion form supported by OpenSSL.
Use uncompressed point conversion form for better compatibility.
When the dispatch code was refactored in libdns, the netmgr was changed
to return ISC_R_SHUTTINGDOWN when the netmgr is shutting down, and the
ISC_R_CANCELED is now reserved only for situation where the callback was
canceled by the caller.
This change wasn't reflected in the controlconf.c channel which was
still looking for ISC_R_CANCELED as the shutdown event.
This commit converts the license handling to adhere to the REUSE
specification. It specifically:
1. Adds used licnses to LICENSES/ directory
2. Add "isc" template for adding the copyright boilerplate
3. Changes all source files to include copyright and SPDX license
header, this includes all the C sources, documentation, zone files,
configuration files. There are notes in the doc/dev/copyrights file
on how to add correct headers to the new files.
4. Handle the rest that can't be modified via .reuse/dep5 file. The
binary (or otherwise unmodifiable) files could have license places
next to them in <foo>.license file, but this would lead to cluttered
repository and most of the files handled in the .reuse/dep5 file are
system test files.
The isc__nm_tcp_resumeread() was using maybe_enqueue function to enqueue
netmgr event which could case the read callback to be executed
immediately if there was enough data waiting in the TCP queue.
If such thing would happen, the read callback would be called before the
previous read callback was finished and the worker receive buffer would
be still marked "in use" causing a assertion failure.
This would affect only raw TCP channels, e.g. rndc and http statistics.
