This might be removed when we stop supporting older libuv versions.

The first step in all existing setup.sh scripts is to call clean.sh.  To
reduce code duplication and ensure all system tests added in the future
behave consistently with existing ones, invoke clean.sh from run.sh
before calling setup.sh.

Since the role of the bin/tests/system/clean.sh script has now been
reduced to calling a given system test's clean.sh script, remove the
former altogether and replace its only use with a direct invocation of
the latter.

The "runtime" system test currently fails on Windows because it waits
for named to log a message indicating successful startup ("running"),
but that never happens since named on Windows fails to open the
configuration file as its path includes control characters.

Instead of putting control characters in directory names, put them in
the value of the -D command line switch passed to named, which is used
for identifying an instance of named in a process listing and whose
value is completely ignored by named, but still logged.

While a similar check using special characters appears to be working
fine on Windows for the time being, modify it in the same way to avoid
potential future problems on other platforms and make the test cleaner.

Intertwining release notes from different BIND releases in a single XML
file has caused confusion in the past due to different (and often
arbitrary) approaches to keeping/removing release notes from older
releases on different BIND branches.  Divide doc/arm/notes.xml into
per-version sections to simplify determining the set of changes
introduced by a given release and to make adding/reviewing release notes
less error-prone.

- ns__client_request() is now called by netmgr with an isc_nmhandle_t
  parameter. The handle can then be permanently associated with an
  ns_client object.
- The task manager is paused so that isc_task events that may be
  triggred during client processing will not fire until after the netmgr is
  finished with it. Before any asynchronous event, the client MUST
  call isc_nmhandle_ref(client->handle), to prevent the client from
  being reset and reused while waiting for an event to process. When
  the asynchronous event is complete, isc_nmhandle_unref(client->handle)
  must be called to ensure the handle can be reused later.
- reference counting of client objects is now handled in the nmhandle
  object.  when the handle references drop to zero, the client's "reset"
  callback is used to free temporary resources and reiniialize it,
  whereupon the handle (and associated client) is placed in the
  "inactive handles" queue.  when the sysstem is shutdown and the
  handles are cleaned up, the client's "put" callback is called to free
  all remaining resources.
- because client allocation is no longer handled in the same way,
  the '-T clienttest' option has now been removed and is no longer
  used by any system tests.
- the unit tests require wrapping the isc_nmhandle_unref() function;
  when LD_WRAP is supported, that is used. otherwise we link a
  libwrap.so interposer library and use that.

This is a replacement for the existing isc_socket and isc_socketmgr
implementation. It uses libuv for asynchronous network communication;
"networker" objects will be distributed across worker threads reading
incoming packets and sending them for processing.

UDP listener sockets automatically create an array of "child" sockets
so each worker can listen separately.

TCP sockets are shared amongst worker threads.

A TCPDNS socket is a wrapper around a TCP socket, which handles the
the two-byte length field at the beginning of DNS messages over TCP.

(Other wrapper socket types can be implemented in the future to handle
DNS over TLS, DNS over HTTPS, etc.)

this is a lockless queue based on hazard pointers.

this is a mechanism to allow safe lock-free data structures.

'dnssec-policy' can now also be set on the options and view level and
a zone that does not set 'dnssec-policy' explicitly will inherit it
from the view or options level.

This requires a new keyword to be introduced: 'none'.  If set to
'none' the zone will not be DNSSEC maintained, in other words it will
stay unsigned.  You can use this to break the inheritance.  Of course
you can also break the inheritance by referring to a different
policy.

The keywords 'default' and 'none' are not allowed when configuring
your own dnssec-policy statement.

Add appropriate tests for checking the configuration (checkconf)
and add tests to the kasp system test to verify the inheritance
works.

Edit the kasp system test such that it can deal with unsigned zones
and views (so setting a TSIG on the query).

Add more tests for kasp:

- Add tests for different algorithms.

- Add a test to ensure that an edit in an unsigned zone is
  picked up and properly signed.

- Add two tests that ensures that a zone gets signed when it is
  configured as so-called 'inline-signing'.  In other words, a
  secondary zone that is configured with a 'dnssec-policy'.  A zone
  that is transferred over AXFR or IXFR will get signed.

- Add a test to ensure signatures are reused if they are still
  fresh enough.

- Adds two more tests to verify that expired and unfresh signatures
  will be regenerated.

- Add tests for various cases with keys already available in the
  key-directory.

Add a key manager to named.  If a 'dnssec-policy' is set, 'named'
will run a key manager on the matching keys.  This will do a couple
of things:

1. Create keys when needed (in case of rollover for example)
   according to the set policy.

2. Retire keys that are in excess of the policy.

3. Maintain key states according to "Flexible and Robust Key
   Rollover" [1]. After key manager ran, key files will be saved to
   disk.

   [1] https://matthijsmekking.nl/static/pdf/satin2012-Schaeffer.pdf

KEY GENERATION

Create keys according to DNSSEC policy.  Zones configured with
'dnssec-policy' will allow 'named' to create DNSSEC keys (similar
to dnssec-keymgr) if not available.

KEY ROLLOVER

Rather than determining the desired state from timing metadata,
add a key state goal.  Any keys that are created or picked from the
key ring and selected to be a successor has its key state goal set
to OMNIPRESENT (this key wants to be signing!). At the same time,
a key that is being retired has its key state goal set to HIDDEN.

The keymgr state machine with the three rules will make sure no
introduction or withdrawal of DNSSEC records happens too soon.

KEY TIMINGS

All timings are based on RFC 7583.

The keymgr will return when the next action is happening so
that the zone can set the proper rekey event. Prior to this change
the rekey event will run every hour by default (configurable),
but with kasp we can determine exactly when we need to run again.

The prepublication time is derived from policy.

This commit adds code for generating keys with dnssec-keygen given
a specific dnssec-policy.

The dnssec-policy can be set with a new option '-k'. The '-l'
option can be used to set a configuration file that contains a
specific dnssec-policy.

Because the dnssec-policy dictates how the keys should look like,
many of the existing dnssec-keygen options cannot be used together
with '-k'.

If the dnssec-policy lists multiple keys, dnssec-keygen has now the
possibility to generate multiple keys at one run.

Add two tests for creating keys with '-k': One with the default
policy, one with multiple keys from the configuration.

Add code for creating, configuring, and destroying KASP keys.  When
using the default policy, create one CSK, no rollover.

This stores the dnssec-policy configuration and adds methods to
create, destroy, and attach/detach, as well as find a policy with
the same name in a list.

Also, add structures and functions for creating and destroying
kasp keys.

This commit introduces the initial `dnssec-policy` configuration
statement. It has an initial set of options to deal with signature
and key maintenance.

Add some checks to ensure that dnssec-policy is configured at the
right locations, and that policies referenced to in zone statements
actually exist.

Add some checks that when a user adds the new `dnssec-policy`
configuration, it will no longer contain existing DNSSEC
configuration options.  Specifically: `inline-signing`,
`auto-dnssec`, `dnssec-dnskey-kskonly`, `dnssec-secure-to-insecure`,
`update-check-ksk`, `dnssec-update-mode`, `dnskey-sig-validity`,
and `sig-validity-interval`.

Test a good kasp configuration, and some bad configurations.

Initial design document.

The ttlval configuration types are replaced by duration configuration
types. The duration is an ISO 8601 duration that is going to be used
for DNSSEC key timings such as key lifetimes, signature resign
intervals and refresh periods, etc. But it is also still allowed to
use the BIND ttlval ways of configuring intervals (number plus
optional unit).

A duration is stored as an array of 7 different time parts.
A duration can either be expressed in weeks, or in a combination of
the other datetime indicators.

Add several unit tests to ensure the correct value is parsed given
different string values.

Note: ans6/ans6.py is a helper script that allows tests.sh to open/close
TCP connections to some BIND instance.

The OASIS pkcs11.h header has a restrictive license.  Replace the
pkcs11.h pkcs11f.h and pkcs11t.h headers with pkcs11.h from p11-kit.

For source distribution, the license for the OASIS headers itself
doesn't pose any licensing problem when combined with MPL license, but
it possibly creates problem for downstream distributors of BIND 9.

- the cache-file and check-itegrity options were not needed
- some zones and files were not used

- this required modification to the code that generates grammar text for
  the documentation, because the "dnssec-lookaside" option spanned more
  than one line in doc/misc/options, so grepping out only the lines
  marked "// obsolete" didn't remove the whole option.  this commit adds
  an option to cfg_test to print named.conf clauses only if they don't
  have the obsolete, ancient, test-only, or not-yet-implemented flags
  set.

The isc-config.sh script was introduced before pkg-config as is a purely
historical thing.  There are two reason for removal of isc-config.sh scripts:

a) The BIND 9 libraries are now meant to be used only from BIND 9, so there's no
   reason to provide convenience script to link with the libraries.

b) Even if that was not the case, we should and would replace the isc-config.sh
   with respective pkg-config (.pc) file for every library.

Special, for-tests-only, mode with atomics emulated by a mutex-locked variable - useful for finding atomics congestions

When printing a packet, dnstap-read checks whether its text form takes
up more than the 2048 bytes allocated for the output buffer by default.
If that is the case, the output buffer is automatically expanded, but
the truncated output is left in the buffer, resulting in malformed data
being printed.  Clear the output buffer before expanding it to prevent
this issue from occurring.