# This file is Copyright 2019 Volatility Foundation and licensed under the Volatility Software License 1.0
# which is available at https://www.volatilityfoundation.org/license/vsl-v1.0
#
"""An automagic module to use configuration data to configure and then
construct classes that fulfill the descendants of a :class:`~volatility3.framewo
rk.interfaces.configuration.ConfigurableInterface`."""
import logging
import sys
from typing import List
from volatility3 import framework
from volatility3.framework import constants
from volatility3.framework import interfaces
vollog = logging.getLogger(__name__)
[docs]class ConstructionMagic(interfaces.automagic.AutomagicInterface):
"""Constructs underlying layers.
Class to run through the requirement tree of the :class:`~volatility3.framework.interfaces.configuration.ConfigurableInterface`
and from the bottom of the tree upwards, attempt to construct all
:class:`~volatility3.framework.interfaces.configuration.ConstructableRequirementInterface` based classes.
:warning: This `automagic` should run first to allow existing configurations to have been constructed for use by later automagic
"""
priority = 0
def __call__(
self,
context: interfaces.context.ContextInterface,
config_path: str,
requirement: interfaces.configuration.RequirementInterface,
progress_callback=None,
optional=False,
) -> List[str]:
# Make sure we import the layers, so they can reconstructed
framework.import_files(sys.modules["volatility3.framework.layers"])
result: List[str] = []
if requirement.unsatisfied(context, config_path):
# Having called validate at the top level tells us both that we need to dig deeper
# but also ensures that TranslationLayerRequirements have got the correct subrequirements if their class is populated
subreq_config_path = interfaces.configuration.path_join(
config_path, requirement.name
)
for subreq in requirement.requirements.values():
try:
self(
context,
subreq_config_path,
subreq,
optional=optional or subreq.optional,
)
except Exception as e:
# We don't really care if this fails, it tends to mean the configuration isn't complete for that item
vollog.log(
constants.LOGLEVEL_VVVV, f"Construction Exception occurred: {e}"
)
invalid = subreq.unsatisfied(context, subreq_config_path)
# We want to traverse optional paths, so don't check until we've tried to validate
# We also don't want to emit a debug message when a parent is optional, hence the optional parameter
if invalid and not (optional or subreq.optional):
vollog.log(
constants.LOGLEVEL_V,
f"Failed on requirement: {subreq_config_path}",
)
result.append(
interfaces.configuration.path_join(
subreq_config_path, subreq.name
)
)
if result:
return result
elif isinstance(
requirement, interfaces.configuration.ConstructableRequirementInterface
):
# We know all the subrequirements are filled, so let's populate
requirement.construct(context, config_path)
if progress_callback is not None:
progress_callback(100, "Reconstruction finished")
return []