Rework how we handle import errors.

volatility/cli/__init__.py

@@ -108,10 +108,16 @@ class CommandLine(interfaces.plugins.FileConsumerInterface):
             file_logger.setFormatter(file_formatter)
             vollog.addHandler(file_logger)
             vollog.info("Logging started")
+        if partial_args.verbosity < 3:
+            console.setLevel(30 - (partial_args.verbosity * 10))
+        else:
+            console.setLevel(10 - (partial_args.verbosity - 2))
 
         # Do the initialization
         ctx = contexts.Context()  # Construct a blank context
-        framework.import_files(volatility.plugins)  # Will not log as console's default level is WARNING
+        failures = framework.import_files(volatility.plugins,
+                                          True)  # Will not log as console's default level is WARNING
+        vollog.info("Plugins could not be loaded: " + ", ".join(failures))
         automagics = automagic.available(ctx)
 
         plugin_list = framework.list_plugins()
@@ -141,10 +147,6 @@ class CommandLine(interfaces.plugins.FileConsumerInterface):
         args = parser.parse_args()
         if args.plugin is None:
             parser.error("Please select a plugin to run")
-        if args.verbosity < 3:
-            console.setLevel(30 - (args.verbosity * 10))
-        else:
-            console.setLevel(10 - (args.verbosity - 2))
 
         vollog.log(constants.LOGLEVEL_VVV, "Cache directory used: {}".format(constants.CACHE_PATH))
 

volatility/framework/__init__.py

@@ -82,8 +82,9 @@ def class_subclasses(cls: T) -> typing.Generator[T, None, None]:
             yield return_value
 
 
-def import_files(base_module) -> None:
+def import_files(base_module, ignore_errors = False) -> typing.List[str]:
     """Imports all plugins present under plugins path"""
+    failures = []
     if not isinstance(base_module.__path__, list):
         raise TypeError("[base_module].__path__ must be a list of paths")
     for path in base_module.__path__:
@@ -101,11 +102,13 @@ def import_files(base_module) -> None:
                             __import__(base_module.__name__ + "." + module)
                         except ImportError as e:
                             vollog.debug(str(e))
-                            vollog.warning("Failed to import module {} based on file: {}".format(module, modpath))
-                            raise
+                            vollog.debug("Failed to import module {} based on file: {}".format(module, modpath))
+                            failures.append(base_module.__name__ + "." + module)
+                            if not ignore_errors:
+                                raise
                     else:
                         vollog.info("Skipping existing module: {}".format(module))
-    return None
+    return failures
 
 
 def list_plugins() -> typing.Dict[str, typing.Type[interfaces.plugins.PluginInterface]]:

volatility/plugins/windows/vadyarascan.py

@@ -1,13 +1,6 @@
 import logging
 import typing
 
-try:
-    import yara
-
-    has_yara = True
-except ImportError:
-    has_yara = False
-
 from volatility.framework import interfaces, layers, renderers
 from volatility.framework.renderers import format_hints
 from volatility.framework.symbols.windows import extensions
@@ -16,6 +9,11 @@ from volatility.plugins.windows import pslist
 
 vollog = logging.getLogger(__name__)
 
+try:
+    import yara
+except ImportError:
+    vollog.info("Python Yara module not found, plugin (and dependent plugins) not available")
+
 
 class VadYaraScan(interfaces.plugins.PluginInterface):
 
@@ -79,8 +77,5 @@ class VadYaraScan(interfaces.plugins.PluginInterface):
         return scan_iterator
 
     def run(self):
-        if not has_yara:
-            vollog.error("Please install Yara from https://plusvic.github.io/yara/")
-
         return renderers.TreeGrid([('Offset', format_hints.Hex),
                                    ('Rule', str)], self._generator())

volatility/plugins/yarascan.py

@@ -6,14 +6,13 @@ from volatility.framework.configuration import requirements
 from volatility.framework.interfaces import plugins
 from volatility.framework.renderers import format_hints
 
+vollog = logging.getLogger(__name__)
+
 try:
     import yara
-
-    has_yara = True
-except:
-    has_yara = False
-
-vollog = logging.getLogger(__name__)
+except ImportError:
+    vollog.info("Python Yara module not found, plugin (and dependent plugins) not available")
+    raise
 
 
 class YaraScanner(interfaces.layers.ScannerInterface):
@@ -87,8 +86,5 @@ class YaraScan(plugins.PluginInterface):
             yield format_hints.Hex(offset), name
 
     def run(self):
-        if not has_yara:
-            vollog.error("Please install Yara from https://plusvic.github.io/yara/")
-
         return renderers.TreeGrid([('Offset', format_hints.Hex),
                                    ('Rule', str)], self._generator())