Improve ListRequirement handling (default values, etc).

volatility/cli/__init__.py

@@ -135,6 +135,10 @@ class CommandLine(object):
             for requirement in configurables_list[configurable].get_requirements():
                 value = vargs.get(requirement.name, None)
                 if value is not None:
+                    if isinstance(requirement, requirements.ListRequirement):
+                        if not isinstance(value, list):
+                            raise TypeError("Configuration for ListRequirement was not a list")
+                        value = [requirement.element_type(x) for x in value]
                     if not inspect.isclass(configurables_list[configurable]):
                         config_path = configurables_list[configurable].config_path
                     else:
@@ -228,15 +232,8 @@ class CommandLine(object):
                     if "type" in additional:
                         del additional["type"]
             elif isinstance(requirement, volatility.framework.configuration.requirements.ListRequirement):
-                if requirement.min_elements != requirement.max_elements:
-                    if requirement.min_elements > 0:
-                        additional["nargs"] = "+"
-                    additional["nargs"] = "*"
-                    # We can't test for min_elements > 1 or going over max_elements but rather than warning here,
-                    # we expect the plugin to fail validation instead
-                else:
-                    additional["nargs"] = requirement.max_elements
-                additional["type"] = requirement.element_type
+                # This is a trick to generate a list of values
+                additional["type"] = lambda x: x.split(',')
             elif isinstance(requirement, volatility.framework.configuration.requirements.ChoiceRequirement):
                 additional["type"] = str
                 additional["choices"] = requirement.choices

volatility/framework/configuration/requirements.py

@@ -81,9 +81,15 @@ class ListRequirement(interfaces_configuration.RequirementInterface):
 
     def unsatisfied(self, context: interfaces.context.ContextInterface, config_path: str) -> typing.List[str]:
         """Check the types on each of the returned values and their number and then call the element type's check for each one"""
-        value = self.config_value(context, config_path)
-        if value is None:
-            raise ValueError("No value stored in the configuration")
+        default = None
+        value = self.config_value(context, config_path, default)
+        if not value and self.min_elements > 0:
+            vollog.log(constants.LOGLEVEL_V, "ListRequirement Unsatisfied - ListRequirement has non-zero min_elements")
+            return [interfaces_configuration.path_join(config_path, self.name)]
+        if value == default:
+            # We need to differentiate between no value and an empty list
+            vollog.log(constants.LOGLEVEL_V, "ListRequirement Unsatisfied - Value was not specified")
+            return [interfaces_configuration.path_join(config_path, self.name)]
         if not isinstance(value, list):
             # TODO: Check this is the correct response for an error
             raise ValueError("Unexpected config value found: {}".format(repr(value)))
@@ -94,7 +100,8 @@ class ListRequirement(interfaces_configuration.RequirementInterface):
             vollog.log(constants.LOGLEVEL_V, "TypeError - Too many values provided to list option.")
             return [interfaces_configuration.path_join(config_path, self.name)]
         if not all([self._check_type(element, self.element_type) for element in value]):
-            vollog.log(constants.LOGLEVEL_V, "TypeError - At least one element in the list is not of the correct type.")
+            vollog.log(constants.LOGLEVEL_V,
+                       "TypeError - At least one element in the list is not of the correct type.")
             return [interfaces_configuration.path_join(config_path, self.name)]
         return []
 

volatility/framework/interfaces/automagic.py

@@ -69,14 +69,16 @@ class AutomagicInterface(interfaces_configuration.ConfigurableInterface, metacla
 
         :param context: Context on which to operate
         :param config_path: Configuration path of the top-level requirement
-        :param requirement: Top-level requirement whose subrequirements will all be searched
+        :param requirement_root: Top-level requirement whose subrequirements will all be searched
+        :param requirement_type: Type of requirement to find
+        :param shortcut: Only returns requirements that live under unsatisfied requirements
         :return: A list of tuples containing the config_path, sub_config_path and requirement identifying the SymbolRequirements
         """
         sub_config_path = interfaces_configuration.path_join(config_path, requirement_root.name)
         results = []
         recurse = not shortcut
         if isinstance(requirement_root, requirement_type):
-            if not shortcut or requirement_root.unsatisfied(context, config_path):
+            if recurse or requirement_root.unsatisfied(context, config_path):
                 results.append((config_path, sub_config_path, requirement_root))
         else:
             recurse = True