Changes to expose FAT data stream extents log2timeline#597

.pylintrc

@@ -98,6 +98,7 @@ disable=assignment-from-none,
         locally-disabled,
         locally-enabled,
         logging-format-interpolation,
+        logging-fstring-interpolation,
         metaclass-assignment,
         missing-param-doc,
         no-absolute-import,

config/dpkg/control

@@ -9,7 +9,7 @@ Homepage: https://github.com/log2timeline/dfvfs
 
 Package: python3-dfvfs
 Architecture: all
-Depends: libbde-python3 (>= 20220121), libewf-python3 (>= 20131210), libfsapfs-python3 (>= 20220709), libfsext-python3 (>= 20220829), libfsfat-python3 (>= 20220816), libfshfs-python3 (>= 20220831), libfsntfs-python3 (>= 20211229), libfsxfs-python3 (>= 20220829), libfvde-python3 (>= 20220121), libfwnt-python3 (>= 20210717), libluksde-python3 (>= 20220121), libmodi-python3 (>= 20210405), libphdi-python3 (>= 20220228), libqcow-python3 (>= 20201213), libsigscan-python3 (>= 20191221), libsmdev-python3 (>= 20140529), libsmraw-python3 (>= 20140612), libvhdi-python3 (>= 20201014), libvmdk-python3 (>= 20140421), libvsgpt-python3 (>= 20211115), libvshadow-python3 (>= 20160109), libvslvm-python3 (>= 20160109), python3-cffi-backend (>= 1.9.1), python3-cryptography (>= 2.0.2), python3-dfdatetime (>= 20220816), python3-dtfabric (>= 20220219), python3-idna (>= 2.5), python3-pytsk3 (>= 20210419), python3-pyxattr (>= 0.7.2), python3-yaml (>= 3.10), ${misc:Depends}
+Depends: libbde-python3 (>= 20220121), libewf-python3 (>= 20131210), libfsapfs-python3 (>= 20220709), libfsext-python3 (>= 20220829), libfsfat-python3 (>= 20220925), libfshfs-python3 (>= 20220831), libfsntfs-python3 (>= 20211229), libfsxfs-python3 (>= 20220829), libfvde-python3 (>= 20220121), libfwnt-python3 (>= 20210717), libluksde-python3 (>= 20220121), libmodi-python3 (>= 20210405), libphdi-python3 (>= 20220228), libqcow-python3 (>= 20201213), libsigscan-python3 (>= 20191221), libsmdev-python3 (>= 20140529), libsmraw-python3 (>= 20140612), libvhdi-python3 (>= 20201014), libvmdk-python3 (>= 20140421), libvsgpt-python3 (>= 20211115), libvshadow-python3 (>= 20160109), libvslvm-python3 (>= 20160109), python3-cffi-backend (>= 1.9.1), python3-cryptography (>= 2.0.2), python3-dfdatetime (>= 20220816), python3-dtfabric (>= 20220219), python3-idna (>= 2.5), python3-pytsk3 (>= 20210419), python3-pyxattr (>= 0.7.2), python3-yaml (>= 3.10), ${misc:Depends}
 Description: Python 3 module of dfVFS
  dfVFS, or Digital Forensics Virtual File System, provides read-only access to
  file-system objects from various storage media types and file formats. The goal

dependencies.ini

@@ -66,7 +66,7 @@ version_property: get_version()
 [pyfsfat]
 dpkg_name: libfsfat-python3
 l2tbinaries_name: libfsfat
-minimum_version: 20220816
+minimum_version: 20220925
 pypi_name: libfsfat-python
 rpm_name: libfsfat-python3
 version_property: get_version()

dfvfs/vfs/fat_file_entry.py

@@ -11,6 +11,7 @@
 from dfvfs.path import fat_path_spec
 from dfvfs.resolver import resolver
 from dfvfs.vfs import attribute
+from dfvfs.vfs import extent
 from dfvfs.vfs import fat_directory
 from dfvfs.vfs import file_entry
 
@@ -160,6 +161,31 @@ def size(self):
     """int: size of the file entry in bytes or None if not available."""
     return self._fsfat_file_entry.size
 
+  def GetExtents(self):
+    """Retrieves the extents.
+
+    Returns:
+      list[Extent]: the extents.
+    """
+    if self.entry_type != definitions.FILE_ENTRY_TYPE_FILE:
+      return []
+
+    extents = []
+    for extent_index in range(self._fsfat_file_entry.number_of_extents):
+      extent_offset, extent_size, extent_flags = (
+          self._fsfat_file_entry.get_extent(extent_index))
+
+      if extent_flags & 0x1:
+        extent_type = definitions.EXTENT_TYPE_SPARSE
+      else:
+        extent_type = definitions.EXTENT_TYPE_DATA
+
+      data_stream_extent = extent.Extent(
+          extent_type=extent_type, offset=extent_offset, size=extent_size)
+      extents.append(data_stream_extent)
+
+    return extents
+
   def GetFileObject(self, data_stream_name=''):
     """Retrieves a file-like object of a specific data stream.
 

requirements.txt

@@ -8,7 +8,7 @@ libbde-python >= 20220121
 libewf-python >= 20131210
 libfsapfs-python >= 20220709
 libfsext-python >= 20220829
-libfsfat-python >= 20220816
+libfsfat-python >= 20220925
 libfshfs-python >= 20220831
 libfsntfs-python >= 20211229
 libfsxfs-python >= 20220829

setup.cfg

@@ -21,7 +21,7 @@ requires = libbde-python3 >= 20220121
            libewf-python3 >= 20131210
            libfsapfs-python3 >= 20220709
            libfsext-python3 >= 20220829
-           libfsfat-python3 >= 20220816
+           libfsfat-python3 >= 20220925
            libfshfs-python3 >= 20220831
            libfsntfs-python3 >= 20211229
            libfsxfs-python3 >= 20220829

setup.py

@@ -28,9 +28,8 @@
 
 version_tuple = (sys.version_info[0], sys.version_info[1])
 if version_tuple < (3, 7):
-  print((
-      'Unsupported Python version: {0:s}, version 3.7 or higher '
-      'required.').format(sys.version))
+  print(f'Unsupported Python version: {sys.version:s}, version 3.7 or higher '
+        f'required.')
   sys.exit(1)
 
 # Change PYTHONPATH to include dfvfs so that we can get the version.
@@ -87,8 +86,8 @@ def _make_spec_file(self):
           summary = line[9:]
 
         elif line.startswith('BuildRequires: '):
-          line = 'BuildRequires: {0:s}-setuptools, {0:s}-devel'.format(
-              python_package)
+          line = (f'BuildRequires: {python_package:s}-setuptools, '
+                  f'{python_package:s}-devel')
 
         elif line.startswith('Requires: '):
           requires = line[10:]
@@ -111,7 +110,7 @@ def _make_spec_file(self):
 
         elif line.startswith('%files'):
           lines = [
-              '%files -n {0:s}-%{{name}}'.format(python_package),
+              f'%files -n {python_package:s}-%{{name}}',
               '%defattr(644,root,root,755)',
               '%license LICENSE',
               '%doc ACKNOWLEDGEMENTS AUTHORS README']
@@ -132,17 +131,16 @@ def _make_spec_file(self):
         elif line.startswith('%prep'):
           in_description = False
 
-          python_spec_file.append(
-              '%package -n {0:s}-%{{name}}'.format(python_package))
-          python_summary = 'Python 3 module of {0:s}'.format(summary)
+          python_spec_file.append(f'%package -n {python_package:s}-%{{name}}')
+          python_summary = f'Python 3 module of {summary:s}'
 
           if requires:
-            python_spec_file.append('Requires: {0:s}'.format(requires))
+            python_spec_file.append(f'Requires: {requires:s}')
 
           python_spec_file.extend([
-              'Summary: {0:s}'.format(python_summary),
+              f'Summary: {python_summary:s}',
               '',
-              '%description -n {0:s}-%{{name}}'.format(python_package)])
+              f'%description -n {python_package:s}-%{{name}}'])
 
           python_spec_file.extend(description)
 

tests/vfs/fat_file_entry.py

@@ -210,6 +210,32 @@ def testGetDataStream(self):
     data_stream = file_entry.GetDataStream('')
     self.assertIsNotNone(data_stream)
 
+  def testGetExtents(self):
+    """Tests the GetExtents function."""
+    path_spec = path_spec_factory.Factory.NewPathSpec(
+        definitions.TYPE_INDICATOR_FAT,
+        identifier=self._IDENTIFIER_ANOTHER_FILE,
+        location='\\a_directory\\another_file',
+        parent=self._raw_path_spec)
+    file_entry = self._file_system.GetFileEntryByPathSpec(path_spec)
+    self.assertIsNotNone(file_entry)
+
+    extents = file_entry.GetExtents()
+    self.assertEqual(len(extents), 1)
+
+    self.assertEqual(extents[0].extent_type, definitions.EXTENT_TYPE_DATA)
+    self.assertEqual(extents[0].offset, 31232)
+    self.assertEqual(extents[0].size, 2048)
+
+    path_spec = path_spec_factory.Factory.NewPathSpec(
+        definitions.TYPE_INDICATOR_FAT, identifier=self._IDENTIFIER_A_DIRECTORY,
+        location='\\a_directory', parent=self._raw_path_spec)
+    file_entry = self._file_system.GetFileEntryByPathSpec(path_spec)
+    self.assertIsNotNone(file_entry)
+
+    extents = file_entry.GetExtents()
+    self.assertEqual(len(extents), 0)
+
   def testGetFileEntryByPathSpec(self):
     """Tests the GetFileEntryByPathSpec function."""
     path_spec = path_spec_factory.Factory.NewPathSpec(

utils/dependencies.py

@@ -157,8 +157,7 @@ def _CheckPythonModule(self, dependency):
     """
     module_object = self._ImportPythonModule(dependency.name)
     if not module_object:
-      status_message = 'missing: {0:s}'.format(dependency.name)
-      return False, status_message
+      return False, f'missing: {dependency.name:s}'
 
     if not dependency.version_property:
       return True, dependency.name
@@ -196,13 +195,11 @@ def _CheckPythonModuleVersion(
         module_version = version_method()
 
     if not module_version:
-      status_message = (
-          'unable to determine version information for: {0:s}').format(
-              module_name)
-      return False, status_message
+      return False, (
+          f'unable to determine version information for: {module_name:s}')
 
     # Make sure the module version is a string.
-    module_version = '{0!s}'.format(module_version)
+    module_version = f'{module_version!s}'
 
     # Split the version string and convert every digit into an integer.
     # A string compare of both version strings will yield an incorrect result.
@@ -217,42 +214,38 @@ def _CheckPythonModuleVersion(
       module_version_map = list(
           map(int, self._VERSION_SPLIT_REGEX.split(module_version)))
     except ValueError:
-      status_message = 'unable to parse module version: {0:s} {1:s}'.format(
-          module_name, module_version)
-      return False, status_message
+      return False, (
+          f'unable to parse module version: {module_name:s} {module_version:s}')
 
     if minimum_version:
       try:
         minimum_version_map = list(
             map(int, self._VERSION_SPLIT_REGEX.split(minimum_version)))
       except ValueError:
-        status_message = 'unable to parse minimum version: {0:s} {1:s}'.format(
-            module_name, minimum_version)
-        return False, status_message
+        return False, (
+            f'unable to parse minimum version: {module_name:s} '
+            f'{minimum_version:s}')
 
       if module_version_map < minimum_version_map:
-        status_message = (
-            '{0:s} version: {1!s} is too old, {2!s} or later required').format(
-                module_name, module_version, minimum_version)
-        return False, status_message
+        return False, (
+            f'{module_name:s} version: {module_version!s} is too old, '
+            f'{minimum_version!s} or later required')
 
     if maximum_version:
       try:
         maximum_version_map = list(
             map(int, self._VERSION_SPLIT_REGEX.split(maximum_version)))
       except ValueError:
-        status_message = 'unable to parse maximum version: {0:s} {1:s}'.format(
-            module_name, maximum_version)
-        return False, status_message
+        return False, (
+            f'unable to parse maximum version: {module_name:s} '
+            f'{maximum_version:s}')
 
       if module_version_map > maximum_version_map:
-        status_message = (
-            '{0:s} version: {1!s} is too recent, {2!s} or earlier '
-            'required').format(module_name, module_version, maximum_version)
-        return False, status_message
+        return False, (
+            f'{module_name:s} version: {module_version!s} is too recent, '
+            f'{maximum_version!s} or earlier required')
 
-    status_message = '{0:s} version: {1!s}'.format(module_name, module_version)
-    return True, status_message
+    return True, f'{module_name:s} version: {module_version!s}'
 
   def _ImportPythonModule(self, module_name):
     """Imports a Python module.
@@ -292,10 +285,10 @@ def _PrintCheckDependencyStatus(
       else:
         status_indicator = '[FAILURE]'
 
-      print('{0:s}\t{1:s}'.format(status_indicator, status_message))
+      print(f'{status_indicator:s}\t{status_message:s}')
 
     elif verbose_output:
-      print('[OK]\t\t{0:s}'.format(status_message))
+      print(f'[OK]\t\t{status_message:s}')
 
   def CheckDependencies(self, verbose_output=True):
     """Checks the availability of the dependencies.
@@ -349,7 +342,8 @@ def CheckTestDependencies(self, verbose_output=True):
         continue
 
       result, status_message = self._CheckPythonModule(dependency)
-      if not result:
+
+      if not result and not dependency.is_optional:
         check_result = False
 
       self._PrintCheckDependencyStatus(