Add a BIND9 plugin which, in "reverse" mode, enables the server to build
a synthesized response to a PTR query when the PTR record requested is
not found in the zone. (The plugin won't be called for names below a
delegation point, because it couldn't know whether a name actually
exists within the delegation.)
The dynamically-built name is constructed from a static prefix (passed
as a plugin parameter), the IP address (extracted from the query name)
and a suffx (also passed as a plugin parameter). An "allow-synth"
address-match list is used to limit the network addresses for which
the plugin may generate responses.
The plugin can also be used in "forward" mode, to build synthesized
A/AAAA records from names using the same format as he dynamically-built
PTR names, if the query name and type are not found in the zone.
The same parameters are used when the plugin is in forward mode:
the plugin will react and answer a query if the name matches the
configured prefix and origin, and encodes an IP address that is
within "allow-synth".
Meson is a modern build system that has seen a rise in adoption and some
version of it is available in almost every platform supported.
Compared to automake, meson has the following advantages:
* Meson provides a significant boost to the build and configuration time
by better exploiting parallelism.
* Meson is subjectively considered to be better in readability.
These merits alone justify experimenting with meson as a way of
improving development time and ergonomics. However, there are some
compromises to ensure the transition goes relatively smooth:
* The system tests currently rely on various files within the source
directory. Changing this requirement is a non-trivial task that can't
be currently justified. Currently the last compiled build directory
writes into the source tree which is in turn used by pytest.
* The minimum version supported has been fixed at 0.61. Increasing this
value will require choosing a baseline of distributions that can
package with meson. On the contrary, there will likely be an attempt
to decrease this value to ensure almost universal support for building
BIND 9 with meson.
