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.
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.
It is trivial to fully cleanup memory on all the error paths in
named-rrchecker, many of which are triggered by bad user input.
This involves freeing lex and mctx if they exist when fatal is
called.
* rbt node chains were sized to allow for bitstring labels, so they
had 256 levels; but in the absence of bistrings, 128 is enough.
* dns_byaddr_createptrname() had a redundant options argument,
and a very outdated doc comment.
* A number of comments referred to bitstring labels in a way that is
no longer helpful. (A few informative comments remain.)
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that the feature is obsolete and should not be used.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.
The isc_buffer_reserve() would be passed a reference to the buffer
pointer, which was unnecessary as the pointer would never be changed
in the current implementation. Remove the extra dereference.
The various factors like NS_PER_MS are now defined in a single place
and the names are no longer inconsistent. I chose the _PER_SEC names
rather than _PER_S because it is slightly more clear in isolation;
but the smaller units are always NS, US, and MS.
This change prepares ground for sending DNS requests using DoT,
which, in particular, will be used for forwarding dynamic updates
to TLS-enabled primaries.
dns_request_create() was a front-end to dns_request_createvia() that
was only used by test binaries. dns_request_createvia() has been
renamed to dns_request_create(), and the test programs that formerly
used dns_request_create() have been updated to use the new parameters.
YAML strings should be quoted if they contain colon characters.
Since IPv6 addresses do, we now quote the query_address and
response_address strings in all YAML output.
Previously:
* applications were using isc_app as the base unit for running the
application and signal handling.
* networking was handled in the netmgr layer, which would start a
number of threads, each with a uv_loop event loop.
* task/event handling was done in the isc_task unit, which used
netmgr event loops to run the isc_event calls.
In this refactoring:
* the network manager now uses isc_loop instead of maintaining its
own worker threads and event loops.
* the taskmgr that manages isc_task instances now also uses isc_loopmgr,
and every isc_task runs on a specific isc_loop bound to the specific
thread.
* applications have been updated as necessary to use the new API.
* new ISC_LOOP_TEST macros have been added to enable unit tests to
run isc_loop event loops. unit tests have been updated to use this
where needed.
* isc_timer was rewritten using the uv_timer, and isc_timermgr_t was
completely removed; isc_timer objects are now directly created on the
isc_loop event loops.
* the isc_timer API has been simplified. the "inactive" timer type has
been removed; timers are now stopped by calling isc_timer_stop()
instead of resetting to inactive.
* isc_manager now creates a loop manager rather than a timer manager.
* modules and applications using isc_timer have been updated to use the
new API.
It's wasteful to use 20 bytes and a pointer indirection to represent
two bits of information, so turn the struct into an enum. And change
the names of the enumeration constants to make the intent more clear.
This change introduces some inline functions into another header,
which confuses `gcovr` when it is trying to collect code coverage
statistics. So, in the CI job, copy more header files into a directory
where `gcovr` looks for them.
There was a proposal in the late 1990s that it might, but it turned
out to be unworkable. See RFC 6891, Extension Mechanisms for
DNS (EDNS(0)), section 5, Extended Label Types.
The remnants of the code that supported this in BIND are redundant.
Previously, tasks could be created either unbound or bound to a specific
thread (worker loop). The unbound tasks would be assigned to a random
thread every time isc_task_send() was called. Because there's no logic
that would assign the task to the least busy worker, this just creates
unpredictability. Instead of random assignment, bind all the previously
unbound tasks to worker 0, which is guaranteed to exist.
The dns_message_gettempname(), dns_message_gettemprdata(),
dns_message_gettemprdataset(), and dns_message_gettemprdatalist() always
succeeds because the memory allocation cannot fail now. Change the API
to return void and cleanup all the use of aforementioned functions.
After removing the isc_task_onshutdown(), the isc_task_shutdown() and
isc_task_destroy() became obsolete.
Remove calls to isc_task_shutdown() and replace the calls to
isc_task_destroy() with isc_task_detach().
Simplify the internal logic to destroy the task when the last reference
is removed.
Man pages for dig/mdig/delv used `.. option:: +[no]bla` to describe two
options at once, and very old Sphinx does not support that [] in option
names.
Solution is to split negative and positive options into `+bla, +nobla`
form. In the end it improves readability because it transforms hard to
read strings with double brackets from
`+[no]subnet=addr[/prefix-length]` to
`+subnet=addr[/prefix-length], +nosubnet`.
As a side-effect it also allows easier linking to dig/mdig/delv options
using their name directly instead of always overriding the link target
to `+[no]bla` form.
Transformation was done using regex:
s/:: +\[no\]\(.*\)/:: +\1, +no\1
... and manual review around occurences matching regex
+no.*=
Fixes: #3301
There are a couple of problems with dns_request_createvia(): a UDP
retry count of zero means unlimited retries (it should mean no
retries), and the overall request timeout is not enforced. The
combination of these bugs means that requests can be retried forever.
This change alters calls to dns_request_createvia() to avoid the
infinite retry bug by providing an explicit retry count. Previously,
the calls specified infinite retries and relied on the limit implied
by the overall request timeout and the UDP timeout (which did not work
because the overall timeout is not enforced). The `udpretries`
argument is also changed to be the number of retries; previously, zero
was interpreted as infinity because of an underflow to UINT_MAX, which
appeared to be a mistake. And `mdig` is updated to match the change in
retry accounting.
The bug could be triggered by zone maintenance queries, including
NOTIFY messages, DS parental checks, refresh SOA queries and stub zone
nameserver lookups. It could also occur with `nsupdate -r 0`.
(But `mdig` had its own code to avoid the bug.)
C11 has builtin support for _Noreturn function specifier with
convenience noreturn macro defined in <stdnoreturn.h> header.
Replace ISC_NORETURN macro by C11 noreturn with fallback to
__attribute__((noreturn)) if the C11 support is not complete.
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.
Replace :manpage: with :iscman: to generate internal hyperlinks. That
way reader can use links even when offline, and jumps to man pages
for the same version.
Formerly HTML version of man pages did not have links in See Also
section because :manpage: role in Sphinx can generate only external
hyperlinks - and we do not have that enabled.
Enabling the Sphinx :manpage: linking could reliably create hyperlinks
only to external URLs, but that would take users to another version
of docs.
Generated by:
find bin -name '*.rst' | xargs sed -i -e 's/:manpage:`\([^(]\+\)(\([0-9]\))`/:iscman:`\1(\2) <\1>`/g'
+ hand-edit to revert change for mmencode reference which is
not provided in our source tree.
Use the new role :iscman: to replace all occurences or ``binary``
with :iscman:`binary`, creating a hyperlink to the manual page.
Generated using:
find bin -name *.rst | xargs fgrep --files-with-matches '.. iscman' | xargs -I{} -n1 basename {} .rst > /tmp/progs
for PROG in $(cat /tmp/progs); do find -name '*.rst' | xargs sed -i -e "s/\`\`$PROG\`\`/:iscman:\`$PROG\`/g"; done
Additional hand-edits were done mainly around filter-aaaa and
filter-a which are program names and and option names at the
same time. Couple more edits was neede to fix .rst syntax broken by
automatic replacement.
Sphinx has it's own :program: syntax for refering to program names.
Use it for self-references in manual pages. These self-references are
not clickable and not as eye-cathing as links, which is a good thing.
There is no point in attracting attention to ``dig`` several times on a
single page dedicated to dig itself.
Substituted automatically using:
find bin -name *.rst | xargs fgrep --files-with-matches '.. program' | xargs -n1 bash /tmp/repl.sh
With /tmp/repl.sh being:
BASE=$(basename "$1" .rst)
sed -i -e "s/\`\`$BASE\`\`/:program:\`$BASE\`/g" "$1"
The new directive and role "iscman" allow to tag & reference man pages in
our source tree. Essentially it is just namespacing for ISC man pages,
but it comes with couple benefits.
Differences from .. _man_program label we formerly used:
- Does not expand :ref:`man_program` into full text of the page header.
- Generates index entry with category "manual page".
- Rendering style is closer to ubiquitous to the one produced
by ``named`` syntax.
Differences from Sphinx built-in :manpage: role:
- Supports all builders with support for cross-references.
- Generates internal links (unlike :manpage: which generates external
URLs).
- Checks that target exists withing our source tree.
Side-effect of hyperlinking is that typos in program and option names
are now detected by Sphinx.
Candidate -options were detected using:
find -name *.rst | xargs grep '``-[^`]'
and then modified from ``-o`` to :option:`-o` using regex
s/``\(-[^`]\+\)``/:option:`\1`/
+ manual modifications where necessary.
Non-hyphenated options were detected by looking at context around
program names:
find bin -name *.rst | xargs -I{} -n1 basename {} .rst | sort -u
and grepping for program name with trailing whitespace.
Stand-alone program names like ``named`` are not hyperlinked in this
commit.
The markup allows referencing individual options, and also makes them
more legible (no more thin red text on gray background).
Most of the work was done using regexes:
s/^``-\(.*\)``$/.. option:: -\1\r/
s/^``+\(.*\)``$/.. option:: +\1\r/
on bin/**/*.rst files along with visual inspection and hand-edits,
mostly for positional arguments.
Regex for rndc.rst:
s/^``\(.*\)``/.. option:: \1\r/
+ hand edits to remove extra asterisk and whitespace here and there.
Building BIND 9 with older version of BIND 9 installed would result in
build failure. Fix the last two remaining cases where <prog>_CFLAGS was
being used leading to wrong order of the build flags on the command line.
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.
Remove the dynamic registration of result codes. Convert isc_result_t
from unsigned + #defines into 32-bit enum type in grand unified
<isc/result.h> header. Keep the existing values of the result codes
even at the expense of the description and identifier tables being
unnecessary large.
Additionally, add couple of:
switch (result) {
[...]
default:
break;
}
statements where compiler now complains about missing enum values in the
switch statement.
- startrecv() and getnext() have been rewritten.
- Don't set TCP flag when connecting a UDP dispatch.
- Prevent TCP connections from trying to connect twice.
- dns_dispatch_gettcp() can now find a matching TCP dispatch that has
not yet fully connected, and attach to it. when the connection is
completed, the connect callbacks are run for all of the pending
entries.
- An atomic 'state' variable is now used for connection state instead of
attributes.
- When dns_dispatch_cancel() is called on a TCP dispatch entry, only
that one entry is canceled. the dispatch itself should not be shut
down until there are no dispatch entries left associated with it.
- Other incidental cleanup, including removing DNS_DISPATCHATTR_IPV4 and
_IPV6 (they were being set in the dispatch attributes but never used),
cleaning up dns_requestmgr_create(), and renaming dns_dispatch_read()
to the more descriptive dns_dispatch_resume().
- Responses received by the dispatch are no longer sent to the caller
via a task event, but via a netmgr-style recv callback. the 'action'
parameter to dns_dispatch_addresponse() is now called 'response' and
is called directly from udp_recv() or tcp_recv() when a valid response
has been received.
- All references to isc_task and isc_taskmgr have been removed from
dispatch functions.
- All references to dns_dispatchevent_t have been removed and the type
has been deleted.
- Added a task to the resolver response context, to be used for fctx
events.
- When the caller cancels an operation, the response handler will be
called with ISC_R_CANCELED; it can abort immediately since the caller
will presumably have taken care of cleanup already.
- Cleaned up attach/detach in resquery and request.
Since every dispsock was associated with a dispentry anyway (though not
always vice versa), the members of dispsock have been combined into
dispentry, which is now reference-counted. dispentry objects are now
attached before connecting and detached afterward to prevent races
between the connect callback and dns_dispatch_removeresponse().
Dispatch and dispatchmgr objects are now reference counted as well, and
the shutdown process has been simplified. reference counting of
resquery and request objects has also been cleaned up significantly.
dns_dispatch_cancel() now flags a dispentry as having been canceled, so
that if the connect callback runs after cancellation, it will not
initiate a read.
The isblackholed() function has been simplified.
The flow of operations in dispatch is changing and will now be similar
for both UDP and TCP queries:
1) Call dns_dispatch_addresponse() to assign a query ID and register
that we'll be listening for a response with that ID soon. the
parameters for this function include callback functions to inform the
caller when the socket is connected and when the message has been
sent, as well as a task action that will be sent when the response
arrives. (later this could become a netmgr callback, but at this
stage to minimize disruption to the calling code, we continue to use
isc_task for the response event.) on successful completion of this
function, a dispatch entry object will be instantiated.
2) Call dns_dispatch_connect() on the dispatch entry. this runs
isc_nm_udpconnect() or isc_nm_tcpdnsconnect(), as needed, and begins
listening for responses. the caller is informed via a callback
function when the connection is established.
3) Call dns_dispatch_send() on the dispatch entry. this runs
isc_nm_send() to send a request.
4) Call dns_dispatch_removeresponse() to terminate listening and close
the connection.
Implementation comments below:
- As we will be using netmgr buffers now. code to send the length in
TCP queries has also been removed as that is handled by the netmgr.
- TCP dispatches can be used by multiple simultaneous queries, so
dns_dispatch_connect() now checks whether the dispatch is already
connected before calling isc_nm_tcpdnsconnect() again.
- Running dns_dispatch_getnext() from a non-network thread caused a
crash due to assertions in the netmgr read functions that appear to be
unnecessary now. the assertions have been removed.
- fctx->nqueries was formerly incremented when the connection was
successful, but is now incremented when the query is started and
decremented if the connection fails.
- It's no longer necessary for each dispatch to have a pool of tasks, so
there's now a single task per dispatch.
- Dispatch code to avoid UDP ports already in use has been removed.
- dns_resolver and dns_request have been modified to use netmgr callback
functions instead of task events. some additional changes were needed
to handle shutdown processing correctly.
- Timeout processing is not yet fully converted to use netmgr timeouts.
- Fixed a lock order cycle reported by TSAN (view -> zone-> adb -> view)
by by calling dns_zt functions without holding the view lock.
- Many dispatch attributes can be set implicitly instead of being passed
in. we can infer whether to set DNS_DISPATCHATTR_TCP or _UDP from
whether we're calling dns_dispatch_createtcp() or _createudp(). we
can also infer DNS_DISPATCHATTR_IPV4 or _IPV6 from the addresses or
the socket that were passed in.
- We no longer use dup'd sockets in UDP dispatches, so the 'dup_socket'
parameter has been removed from dns_dispatch_createudp(), along with
the code implementing it. also removed isc_socket_dup() since it no
longer has any callers.
- The 'buffersize' parameter was ignored and has now been removed;
buffersize is now fixed at 4096.
- Maxbuffers and maxrequests don't need to be passed in on every call to
dns_dispatch_createtcp() and _createudp().
In all current uses, the value for mgr->maxbuffers will either be
raised once from its default of 20000 to 32768, or else left
alone. (passing in a value lower than 20000 does not lower it.) there
isn't enough difference between these values for there to be any need
to configure this.
The value for disp->maxrequests controls both the quota of concurrent
requests for a dispatch and also the size of the dispatch socket
memory pool. it's not clear that this quota is necessary at all. the
memory pool size currently starts at 32768, but is sometimes lowered
to 4096, which is definitely unnecessary.
This commit sets both values permanently to 32768.
- Previously TCP dispatches allocated their own separate QID table,
which didn't incorporate a port table. this commit removes
per-dispatch QID tables and shares the same table between all
dispatches. since dispatches are created for each TCP socket, this may
speed up the dispatch allocation process. there may be a slight
increase in lock contention since all dispatches are sharing a single
QID table, but since TCP sockets are used less often than UDP
sockets (which were already sharing a QID table), it should not be a
substantial change.
- The dispatch port table was being used to determine whether a port was
already in use; if so, then a UDP socket would be bound with
REUSEADDR. this commit removes the port table, and always binds UDP
sockets that way.
