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.
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>
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.
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.)
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.
For some applications, it's useful to not listen on full battery of
threads. Add workers argument to all isc_nm_listen*() functions and
convenience ISC_NM_LISTEN_ONE and ISC_NM_LISTEN_ALL macros.
Previously, it was possible to assign a bit of memory space in the
nmhandle to store the client data. This was complicated and prevents
further refactoring of isc_nmhandle_t caching (future work).
Instead of caching the data in the nmhandle, allocate the hot-path
ns_client_t objects from per-thread clientmgr memory context and just
assign it to the isc_nmhandle_t via isc_nmhandle_set().
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.
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.
Commit 9ee60e7a17bf34c7ef7f4d79e6a00ca45444ec8c enabled netmgr shutdown
to cause read callbacks for active control channel sockets to be invoked
with the ISC_R_SHUTTINGDOWN result code. However, control channel code
only recognizes ISC_R_CANCELED as an indicator of an in-progress netmgr
shutdown (which was correct before the above commit). This discrepancy
enables the following scenario to happen in rare cases:
1. A control channel request is received and responded to. libuv
manages to write the response to the TCP socket, but the completion
callback (control_senddone()) is yet to be invoked.
2. Server shutdown is initiated. All TCP sockets are shut down, which
i.a. causes control_recvmessage() to be invoked with the
ISC_R_SHUTTINGDOWN result code. As the result code is not
ISC_R_CANCELED, control_recvmessage() does not set
listener->controls->shuttingdown to 'true'.
3. control_senddone() is called with the ISC_R_SUCCESS result code. As
neither listener->controls->shuttingdown is 'true' nor is the result
code ISC_R_CANCELED, reading is resumed on the control channel
socket. However, this read can never be completed because the read
callback on that socket was cleared when the TCP socket was shut
down. This causes a reference on the socket's handle to be held
indefinitely, leading to a hang upon shutdown.
Ensure listener->controls->shuttingdown is also set to 'true' when
control_recvmessage() is invoked with the ISC_R_SHUTTINGDOWN result
code. This ensures the send completion callback does not resume reading
after the control channel socket is shut down.
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.
Continuing the effort to move all uses of the isc_socket API into
dispatch.c, this commit removes the dns_tcpmsg module entirely, as
dispatch was its only caller, and moves the parts of its functionality
that were being used into the dispatch module.
This code will be removed when we switch to using netmgr TCPDNS.
if a control channel listener was configured with more than one
key algorithm, message verification would be attempted with each
algorithm in turn. if the first key failed due to the wrong
signature length, the entire verification process was aborted,
rather than continuing on to try with another key.
The Windows support has been completely removed from the source tree
and BIND 9 now no longer supports native compilation on Windows.
We might consider reviewing mingw-w64 port if contributed by external
party, but no development efforts will be put into making BIND 9 compile
and run on Windows again.
configuring with --enable-mutex-atomics flagged these incorrectly
initialised variables on systems where pthread_mutex_init doesn't
just zero out the structure.
The isc_nmiface_t type was holding just a single isc_sockaddr_t,
so we got rid of the datatype and use plain isc_sockaddr_t in place
where isc_nmiface_t was used before. This means less type-casting and
shorter path to access isc_sockaddr_t members.
At the same time, instead of keeping the reference to the isc_sockaddr_t
that was passed to us when we start listening, we will keep a local
copy. This prevents the data race on destruction of the ns_interface_t
objects where pending nmsockets could reference the sockaddr of already
destroyed ns_interface_t object.
Previously, netmgr, taskmgr, timermgr and socketmgr all had their own
isc_<*>mgr_create() and isc_<*>mgr_destroy() functions. The new
isc_managers_create() and isc_managers_destroy() fold all four into a
single function and makes sure the objects are created and destroy in
correct order.
Especially now, when taskmgr runs on top of netmgr, the correct order is
important and when the code was duplicated at many places it's easy to
make mistake.
The former isc_<*>mgr_create() and isc_<*>mgr_destroy() functions were
made private and a single call to isc_managers_create() and
isc_managers_destroy() is required at the program startup / shutdown.
Removed redundant 'listener != NULL' check.
1191cleanup:
CID 304936 (#1 of 1): Dereference before null check (REVERSE_INULL)
check_after_deref: Null-checking listener suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
1192 if (listener != NULL) {
1193 isc_refcount_decrement(&listener->refs);
1194 listener->exiting = true;
1195 free_listener(listener);
1196 }
When `rndc stop` is received, the isc_app_shutdown() was being called
before response to the rndc client has been sent; as the
isc_app_shutdown() also tears down the netmgr, the message was never
sent and rndc would complain about connection being interrupted in the
middle of the transaction. We now postpone the shutdown after the rndc
response has been sent.
1. The isc__nm_tcp_send() and isc__nm_tcp_read() was not checking
whether the socket was still alive and scheduling reads/sends on
closed socket.
2. The isc_nm_read(), isc_nm_send() and isc_nm_resumeread() have been
changed to always return the error conditions via the callbacks, so
they always succeed. This applies to all protocols (UDP, TCP and
TCPDNS).
The controllistener could be freed before the event posted by
isc_nm_stoplistening() has been processed. This commit adds
a reference counter to the controllistener to determine when
to free the listener.
Attaching and detaching handle pointers will make it easier to
determine where and why reference counting errors have occurred.
A handle needs to be referenced more than once when multiple
asynchronous operations are in flight, so callers must now maintain
multiple handle pointers for each pending operation. For example,
ns_client objects now contain:
- reqhandle: held while waiting for a request callback (query,
notify, update)
- sendhandle: held while waiting for a send callback
- fetchhandle: held while waiting for a recursive fetch to
complete
- updatehandle: held while waiting for an update-forwarding
task to complete
control channel connection objects now contain:
- readhandle: held while waiting for a read callback
- sendhandle: held while waiting for a send callback
- cmdhandle: held while an rndc command is running
httpd connections contain:
- readhandle: held while waiting for a read callback
- sendhandle: held while waiting for a send callback
When we're shutting the system down via "rndc stop" or "rndc halt",
or reconfiguring the control channel, there are potential shutdown
races between the server task and network manager. These are adressed by:
- purging any pending command tasks when shutting down the control channel
- adding an extra handle reference before the command handler to
ensure the handle can't be deleted out from under us before calling
command_respond()
- using an isc_task to execute all rndc functions makes it relatively
simple for them to acquire task exclusive mode when needed
- control_recvmessage() has been separated into two functions,
control_recvmessage() and control_respond(). the respond function
can be called immediately from control_recvmessage() when processing
a nonce, or it can be called after returning from the task event
that ran the rndc command function.
- updated libisccc to use netmgr events
- updated rndc to use isc_nm_tcpconnect() to establish connections
- updated control channel to use isc_nm_listentcp()
open issues:
- the control channel timeout was previously 60 seconds, but it is now
overridden by the TCP idle timeout setting, which defaults to 30
seconds. we should add a function that sets the timeout value for
a specific listener socket, instead of always using the global value
set in the netmgr. (for the moment, since 30 seconds is a reasonable
timeout for the control channel, I'm not prioritizing this.)
- the netmgr currently has no support for UNIX-domain sockets; until
this is addressed, it will not be possible to configure rndc to use
them. we will need to either fix this or document the change in
behavior.
Due to lack of synchronization, whenever named was being requested to
stop using rndc, controlconf.c module could be trying to access an already
released pointer through named_g_server->interfacemgr in a separate
thread.
The race could only be triggered if named was being shutdown and more
rndc connections were ocurring at the same time.
This fix correctly checks if the server is shutting down before opening
a new rndc connection.
The rewrite of BIND 9 build system is a large work and cannot be reasonable
split into separate merge requests. Addition of the automake has a positive
effect on the readability and maintainability of the build system as it is more
declarative, it allows conditional and we are able to drop all of the custom
make code that BIND 9 developed over the years to overcome the deficiencies of
autoconf + custom Makefile.in files.
This squashed commit contains following changes:
- conversion (or rather fresh rewrite) of all Makefile.in files to Makefile.am
by using automake
- the libtool is now properly integrated with automake (the way we used it
was rather hackish as the only official way how to use libtool is via
automake
- the dynamic module loading was rewritten from a custom patchwork to libtool's
libltdl (which includes the patchwork to support module loading on different
systems internally)
- conversion of the unit test executor from kyua to automake parallel driver
- conversion of the system test executor from custom make/shell to automake
parallel driver
- The GSSAPI has been refactored, the custom SPNEGO on the basis that
all major KRB5/GSSAPI (mit-krb5, heimdal and Windows) implementations
support SPNEGO mechanism.
- The various defunct tests from bin/tests have been removed:
bin/tests/optional and bin/tests/pkcs11
- The text files generated from the MD files have been removed, the
MarkDown has been designed to be readable by both humans and computers
- The xsl header is now generated by a simple sed command instead of
perl helper
- The <irs/platform.h> header has been removed
- cleanups of configure.ac script to make it more simpler, addition of multiple
macros (there's still work to be done though)
- the tarball can now be prepared with `make dist`
- the system tests are partially able to run in oot build
Here's a list of unfinished work that needs to be completed in subsequent merge
requests:
- `make distcheck` doesn't yet work (because of system tests oot run is not yet
finished)
- documentation is not yet built, there's a different merge request with docbook
to sphinx-build rst conversion that needs to be rebased and adapted on top of
the automake
- msvc build is non functional yet and we need to decide whether we will just
cross-compile bind9 using mingw-w64 or fix the msvc build
- contributed dlz modules are not included neither in the autoconf nor automake
this corrects some style glitches such as:
```
long_function_call(arg, arg2, arg3, arg4, arg5, "str"
"ing");
```
...by adjusting the penalties for breaking strings and call
parameter lists.
Both clang-tidy and uncrustify chokes on statement like this:
for (...)
if (...)
break;
This commit uses a very simple semantic patch (below) to add braces around such
statements.
Semantic patch used:
@@
statement S;
expression E;
@@
while (...)
- if (E) S
+ { if (E) { S } }
@@
statement S;
expression E;
@@
for (...;...;...)
- if (E) S
+ { if (E) { S } }
@@
statement S;
expression E;
@@
if (...)
- if (E) S
+ { if (E) { S } }
Also disable the semantic patch as the code needs tweaks here and there because
some destroy functions might not destroy the object and return early if the
object is still in use.
The isc_buffer_allocate() function now cannot fail with ISC_R_MEMORY.
This commit removes all the checks on the return code using the semantic
patch from previous commit, as isc_buffer_allocate() now returns void.
- removed some dead code
- dns_zone_setdbtype is now void as it could no longer return
anything but ISC_R_SUCCESS; calls to it no longer check for a result
- controlkeylist_fromconfig() is also now void
- fixed a whitespace error
