Changes to make vsapm the preferred APM back-end (#736)

log2timeline · May 13, 2023 · 44765f0 · 44765f0
1 parent 2ce8685
commit 44765f0
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Showing 6 changed files with 34 additions and 14 deletions.
diff --git a/dfvfs/lib/definitions.py b/dfvfs/lib/definitions.py
@@ -108,7 +108,7 @@
     TYPE_INDICATOR_VSHADOW])
 
 # The preferred back-ends.
-PREFERRED_APM_BACK_END = TYPE_INDICATOR_TSK_PARTITION
+PREFERRED_APM_BACK_END = TYPE_INDICATOR_APM
 PREFERRED_EXT_BACK_END = TYPE_INDICATOR_EXT
 PREFERRED_FAT_BACK_END = TYPE_INDICATOR_TSK
 PREFERRED_GPT_BACK_END = TYPE_INDICATOR_GPT

diff --git a/dfvfs/vfs/apm_directory.py b/dfvfs/vfs/apm_directory.py
@@ -8,6 +8,9 @@
 class APMDirectory(directory.Directory):
   """File system directory that uses pyvsapm."""
 
+  _STATUS_FLAG_IS_VALID = 0x00000001
+  _STATUS_FLAG_IS_ALLOCATED = 0x00000002
+
   def _EntriesGenerator(self):
     """Retrieves directory entries.
 
@@ -25,8 +28,10 @@ def _EntriesGenerator(self):
         location == self._file_system.LOCATION_ROOT):
       vsapm_volume = self._file_system.GetAPMVolume()
 
-      for partition_index in range(vsapm_volume.number_of_partitions):
-        apm_entry_index = partition_index + 1
-        yield apm_path_spec.APMPathSpec(
-            entry_index=entry_index, location=f'/p{apm_entry_index:d}',
-            parent=self.path_spec.parent)
+      for partition_index, partition in enumerate(vsapm_volume.partitions):
+        if (partition.status_flags & self._STATUS_FLAG_IS_VALID and
+            partition.status_flags & self._STATUS_FLAG_IS_ALLOCATED):
+          apm_entry_index = partition_index + 1
+          yield apm_path_spec.APMPathSpec(
+              entry_index=entry_index, location=f'/p{apm_entry_index:d}',
+              parent=self.path_spec.parent)
diff --git a/tests/analyzer/analyzer.py b/tests/analyzer/analyzer.py
@@ -361,7 +361,7 @@ def testGetVolumeSystemTypeIndicatorsAPM(self):
 
     path_spec = os_path_spec.OSPathSpec(location=test_file)
 
-    expected_type_indicators = [definitions.TYPE_INDICATOR_TSK_PARTITION]
+    expected_type_indicators = [definitions.PREFERRED_APM_BACK_END]
     type_indicators = analyzer.Analyzer.GetVolumeSystemTypeIndicators(path_spec)
     self.assertEqual(type_indicators, expected_type_indicators)
 

diff --git a/tests/helpers/source_scanner.py b/tests/helpers/source_scanner.py
@@ -360,14 +360,29 @@ def testScanOnAPM(self):
     self.assertEqual(
         scan_context.source_type, definitions.SOURCE_TYPE_STORAGE_MEDIA_IMAGE)
 
-    scan_node = self._GetTestScanNode(scan_context)
+    scan_node = scan_context.GetRootScanNode()
+    self.assertIsNotNone(scan_node)
+    self.assertEqual(scan_node.type_indicator, definitions.TYPE_INDICATOR_OS)
+    self.assertEqual(len(scan_node.sub_nodes), 1)
+
+    scan_node = scan_node.sub_nodes[0]
+    self.assertIsNotNone(scan_node)
+    self.assertEqual(scan_node.type_indicator, definitions.TYPE_INDICATOR_RAW)
+    self.assertEqual(len(scan_node.sub_nodes), 1)
+
+    scan_node = scan_node.sub_nodes[0]
     self.assertIsNotNone(scan_node)
     self.assertEqual(
-        scan_node.type_indicator, definitions.TYPE_INDICATOR_TSK_PARTITION)
+        scan_node.type_indicator, definitions.PREFERRED_APM_BACK_END)
 
-    self.assertEqual(len(scan_node.sub_nodes), 5)
+    if scan_node.type_indicator == definitions.TYPE_INDICATOR_TSK_PARTITION:
+      self.assertEqual(len(scan_node.sub_nodes), 5)
+      scan_node = scan_node.sub_nodes[3]
+    else:
+      self.assertEqual(len(scan_node.sub_nodes), 1)
+      scan_node = scan_node.sub_nodes[0]
 
-    scan_node = scan_node.sub_nodes[3].GetSubNodeByLocation('/')
+    scan_node = scan_node.GetSubNodeByLocation('/')
     self.assertIsNotNone(scan_node)
     self.assertEqual(
         scan_node.type_indicator, definitions.PREFERRED_HFS_BACK_END)

diff --git a/tests/vfs/apm_directory.py b/tests/vfs/apm_directory.py
@@ -53,7 +53,7 @@ def testEntriesGenerator(self):
     self.assertIsNotNone(directory)
 
     entries = list(directory.entries)
-    self.assertEqual(len(entries), 2)
+    self.assertEqual(len(entries), 1)
 
 
 if __name__ == '__main__':

diff --git a/tests/volume/apm_volume_system.py b/tests/volume/apm_volume_system.py
@@ -58,9 +58,9 @@ def testIterateVolumes(self):
     volume_system.Open(self._apm_path_spec)
 
     self.assertEqual(volume_system.number_of_sections, 0)
-    self.assertEqual(volume_system.number_of_volumes, 2)
+    self.assertEqual(volume_system.number_of_volumes, 1)
 
-    self.assertEqual(volume_system.volume_identifiers, ['p1', 'p2'])
+    self.assertEqual(volume_system.volume_identifiers, ['p1'])
 
     volume = volume_system.GetVolumeByIndex(0)
     self.assertIsNotNone(volume)