Added attributes support for fsext back-end log2timeline#504

config/dpkg/control

@@ -9,7 +9,7 @@ Homepage: https://github.com/log2timeline/dfvfs
 
 Package: python3-dfvfs
 Architecture: all
-Depends: libbde-python3 (>= 20140531), libewf-python3 (>= 20131210), libfsapfs-python3 (>= 20201107), libfsext-python3 (>= 20210424), libfshfs-python3 (>= 20210530), libfsntfs-python3 (>= 20200921), libfsxfs-python3 (>= 20201114), libfvde-python3 (>= 20160719), libfwnt-python3 (>= 20210717), libluksde-python3 (>= 20200101), libmodi-python3 (>= 20210405), libqcow-python3 (>= 20201213), libsigscan-python3 (>= 20191221), libsmdev-python3 (>= 20140529), libsmraw-python3 (>= 20140612), libvhdi-python3 (>= 20201014), libvmdk-python3 (>= 20140421), libvsgpt-python3 (>= 20210207), libvshadow-python3 (>= 20160109), libvslvm-python3 (>= 20160109), python3-cffi-backend (>= 1.9.1), python3-cryptography (>= 2.0.2), python3-dfdatetime (>= 20210509), python3-dtfabric (>= 20170524), python3-idna (>= 2.5), python3-pytsk3 (>= 20210419), python3-yaml (>= 3.10), ${python3:Depends}, ${misc:Depends}
+Depends: libbde-python3 (>= 20140531), libewf-python3 (>= 20131210), libfsapfs-python3 (>= 20201107), libfsext-python3 (>= 20210721), libfshfs-python3 (>= 20210530), libfsntfs-python3 (>= 20200921), libfsxfs-python3 (>= 20201114), libfvde-python3 (>= 20160719), libfwnt-python3 (>= 20210717), libluksde-python3 (>= 20200101), libmodi-python3 (>= 20210405), libqcow-python3 (>= 20201213), libsigscan-python3 (>= 20191221), libsmdev-python3 (>= 20140529), libsmraw-python3 (>= 20140612), libvhdi-python3 (>= 20201014), libvmdk-python3 (>= 20140421), libvsgpt-python3 (>= 20210207), libvshadow-python3 (>= 20160109), libvslvm-python3 (>= 20160109), python3-cffi-backend (>= 1.9.1), python3-cryptography (>= 2.0.2), python3-dfdatetime (>= 20210509), python3-dtfabric (>= 20170524), python3-idna (>= 2.5), python3-pytsk3 (>= 20210419), python3-yaml (>= 3.10), ${python3:Depends}, ${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

@@ -56,7 +56,7 @@ version_property: get_version()
 [pyfsext]
 dpkg_name: libfsext-python3
 l2tbinaries_name: libfsext
-minimum_version: 20210424
+minimum_version: 20210721
 pypi_name: libfsext-python
 rpm_name: libfsext-python3
 version_property: get_version()

dfvfs/vfs/attribute.py

@@ -1,6 +1,8 @@
 # -*- coding: utf-8 -*-
 """The Virtual File System (VFS) attribute interface."""
 
+from dfvfs.lib import definitions
+
 
 class Attribute(object):
   """Attribute interface."""
@@ -9,3 +11,39 @@ class Attribute(object):
   def type_indicator(self):
     """str: type indicator or None if not known."""
     return getattr(self, 'TYPE_INDICATOR', None)
+
+
+class StatAttribute(object):
+  """Attribute that represents a POSIX stat.
+
+  Attributes:
+    group_identifier (int): group identifier (GID), equivalent to st_gid.
+    inode_number (int): number of the corresponding inode, equivalent to st_ino.
+    mode (int): access mode, equivalent to st_mode & 0x0fff.
+    number_of_links (int): number of hard links, equivalent to st_nlink.
+    owner_user_identifier (int): user identifier (UID) of the owner, equivalent
+        to st_uid.
+    size (int): size, in number of bytes, equivalent to st_size.
+    type (str): file type, value derived from st_mode >> 12.
+  """
+
+  TYPE_DEVICE = definitions.FILE_ENTRY_TYPE_DEVICE
+  TYPE_DIRECTORY = definitions.FILE_ENTRY_TYPE_DIRECTORY
+  TYPE_FILE = definitions.FILE_ENTRY_TYPE_FILE
+  TYPE_LINK = definitions.FILE_ENTRY_TYPE_LINK
+  TYPE_SOCKET = definitions.FILE_ENTRY_TYPE_SOCKET
+  TYPE_PIPE = definitions.FILE_ENTRY_TYPE_PIPE
+  TYPE_WHITEOUT = definitions.FILE_ENTRY_TYPE_WHITEOUT
+
+  def __init__(self):
+    """Initializes an attribute."""
+    super(StatAttribute, self).__init__()
+    self.group_identifier = None
+    self.inode_number = None
+    self.mode = None
+    self.number_of_links = None
+    self.owner_identifier = None
+    self.size = None
+    self.type = None
+
+    # TODO: consider adding st_dev, st_rdev, st_blksize or st_blocks.

dfvfs/vfs/ext_attribute.py

@@ -0,0 +1,107 @@
+# -*- coding: utf-8 -*-
+"""The EXT attribute implementations."""
+
+import os
+
+from dfvfs.lib import errors
+from dfvfs.vfs import attribute
+
+
+class EXTExtendedAttribute(attribute.Attribute):
+  """EXT extended attribute that uses pyfsext."""
+
+  def __init__(self, fsext_extended_attribute):
+    """Initializes an attribute.
+
+    Args:
+      fsext_extended_attribute (pyfsext.extended_attribute): EXT extended
+          attribute.
+
+    Raises:
+      BackEndError: if the pyfsext extended attribute is missing.
+    """
+    if not fsext_extended_attribute:
+      raise errors.BackEndError('Missing pyfsext extended attribute.')
+
+    super(EXTExtendedAttribute, self).__init__()
+    self._fsext_extended_attribute = fsext_extended_attribute
+
+  @property
+  def name(self):
+    """str: name."""
+    return self._fsext_extended_attribute.name
+
+  # Note: that the following functions do not follow the style guide
+  # because they are part of the file-like object interface.
+  # pylint: disable=invalid-name
+
+  def read(self, size=None):
+    """Reads a byte string from the file input/output (IO) object.
+
+    The function will read a byte string of the specified size or
+    all of the remaining data if no size was specified.
+
+    Args:
+      size (Optional[int]): number of bytes to read, where None is all
+          remaining data.
+
+    Returns:
+      bytes: data read.
+
+    Raises:
+      IOError: if the read failed.
+      OSError: if the read failed.
+    """
+    return self._fsext_extended_attribute.read_buffer(size)
+
+  def seek(self, offset, whence=os.SEEK_SET):
+    """Seeks to an offset within the file input/output (IO) object.
+
+    Args:
+      offset (int): offset to seek.
+      whence (Optional[int]): value that indicates whether offset is an
+          absolute or relative position within the file.
+
+    Raises:
+      IOError: if the seek failed.
+      OSError: if the seek failed.
+    """
+    self._fsext_extended_attribute.seek_offset(offset, whence)
+
+  # get_offset() is preferred above tell() by the libbfio layer used in libyal.
+  def get_offset(self):
+    """Retrieves the current offset into the file input/output (IO) object.
+
+    Returns:
+      int: current offset into the file input/output (IO) object.
+
+    Raises:
+      IOError: if the file input/output (IO)-like object has not been opened.
+      OSError: if the file input/output (IO)-like object has not been opened.
+    """
+    return self._fsext_extended_attribute.get_offset()
+
+  # Pythonesque alias for get_offset().
+  def tell(self):
+    """Retrieves the current offset into the file input/output (IO) object."""
+    return self.get_offset()
+
+  def get_size(self):
+    """Retrieves the size of the file input/output (IO) object.
+
+    Returns:
+      int: size of the file input/output (IO) object.
+
+    Raises:
+      IOError: if the file input/output (IO) object has not been opened.
+      OSError: if the file input/output (IO) object has not been opened.
+    """
+    return self._fsext_extended_attribute.get_size()
+
+  def seekable(self):
+    """Determines if a file input/output (IO) object is seekable.
+
+    Returns:
+      bool: True since a file IO object provides a seek method.
+    """
+    return True

dfvfs/vfs/ext_file_entry.py

@@ -6,6 +6,8 @@
 from dfvfs.lib import definitions
 from dfvfs.lib import errors
 from dfvfs.path import ext_path_spec
+from dfvfs.vfs import attribute
+from dfvfs.vfs import ext_attribute
 from dfvfs.vfs import file_entry
 
 
@@ -107,6 +109,24 @@ def __init__(
     self.entry_type = self._ENTRY_TYPES.get(
         fsext_file_entry.file_mode & 0xf000, None)
 
+  def _GetAttributes(self):
+    """Retrieves the attributes.
+
+    Returns:
+      list[Attribute]: attributes.
+    """
+    if self._attributes is None:
+      stat_attribute = self._GetStatAttribute()
+      self._attributes = [stat_attribute]
+
+      for fsext_extended_attribute in (
+          self._fsext_file_entry.extended_attributes):
+        extended_attribute = ext_attribute.EXTExtendedAttribute(
+            fsext_extended_attribute)
+        self._attributes.append(extended_attribute)
+
+    return self._attributes
+
   def _GetDirectory(self):
     """Retrieves a directory.
 
@@ -159,6 +179,23 @@ def _GetStat(self):
 
     return stat_object
 
+  def _GetStatAttribute(self):
+    """Retrieves a stat attribute.
+
+    Returns:
+      StatAttribute: a stat attribute.
+    """
+    stat_attribute = attribute.StatAttribute()
+    stat_attribute.group_identifier = self._fsext_file_entry.group_identifier
+    stat_attribute.inode_number = self._fsext_file_entry.inode_number
+    stat_attribute.mode = self._fsext_file_entry.file_mode & 0x0fff
+    stat_attribute.number_of_links = self._fsext_file_entry.number_of_links
+    stat_attribute.owner_identifier = self._fsext_file_entry.owner_identifier
+    stat_attribute.size = self._fsext_file_entry.size
+    stat_attribute.type = self.entry_type
+
+    return stat_attribute
+
   def _GetSubFileEntries(self):
     """Retrieves a sub file entries generator.
 

dfvfs/vfs/ntfs_attribute.py

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-"""The NTFS attribute implementation."""
+"""The NTFS attribute implementations."""
 
 import pyfwnt
 

requirements.txt

@@ -8,7 +8,7 @@ idna >= 2.5
 libbde-python >= 20140531
 libewf-python >= 20131210
 libfsapfs-python >= 20201107
-libfsext-python >= 20210424
+libfsext-python >= 20210721
 libfshfs-python >= 20210530
 libfsntfs-python >= 20200921
 libfsxfs-python >= 20201114

setup.cfg

@@ -20,7 +20,7 @@ build_requires = python3-setuptools
 requires = libbde-python3 >= 20140531
            libewf-python3 >= 20131210
            libfsapfs-python3 >= 20201107
-           libfsext-python3 >= 20210424
+           libfsext-python3 >= 20210721
            libfshfs-python3 >= 20210530
            libfsntfs-python3 >= 20200921
            libfsxfs-python3 >= 20201114

tests/vfs/ext_file_entry.py

@@ -7,6 +7,8 @@
 from dfvfs.lib import definitions
 from dfvfs.path import factory as path_spec_factory
 from dfvfs.resolver import context
+from dfvfs.vfs import attribute
+from dfvfs.vfs import ext_attribute
 from dfvfs.vfs import ext_file_entry
 from dfvfs.vfs import ext_file_system
 
@@ -19,6 +21,8 @@
 class EXTFileEntryTestWithEXT2(shared_test_lib.BaseTestCase):
   """Tests the EXT file entry on an ext2 image."""
 
+  # pylint: disable=protected-access
+
   _INODE_A_DIRECTORY = 12
   _INODE_A_FILE = 13
   _INODE_A_LINK = 16
@@ -97,6 +101,82 @@ def testModificationTime(self):
     self.assertIsNotNone(file_entry)
     self.assertIsNotNone(file_entry.modification_time)
 
+  def testGetAttributes(self):
+    """Tests the _GetAttributes function."""
+    test_location = '/a_directory/another_file'
+    path_spec = path_spec_factory.Factory.NewPathSpec(
+        definitions.TYPE_INDICATOR_EXT, inode=self._INODE_ANOTHER_FILE,
+        location=test_location, parent=self._raw_path_spec)
+    file_entry = self._file_system.GetFileEntryByPathSpec(path_spec)
+    self.assertIsNotNone(file_entry)
+
+    self.assertIsNone(file_entry._attributes)
+
+    file_entry._GetAttributes()
+    self.assertIsNotNone(file_entry._attributes)
+    self.assertEqual(len(file_entry._attributes), 2)
+
+    test_attribute = file_entry._attributes[0]
+    self.assertIsInstance(test_attribute, attribute.StatAttribute)
+
+    test_attribute = file_entry._attributes[1]
+    self.assertIsInstance(test_attribute, ext_attribute.EXTExtendedAttribute)
+    self.assertEqual(test_attribute.name, 'security.selinux')
+
+    test_attribute_value_data = test_attribute.read()
+    self.assertEqual(
+        test_attribute_value_data, b'unconfined_u:object_r:unlabeled_t:s0\x00')
+
+  def testGetStat(self):
+    """Tests the _GetStat function."""
+    test_location = '/a_directory/another_file'
+    path_spec = path_spec_factory.Factory.NewPathSpec(
+        definitions.TYPE_INDICATOR_EXT, inode=self._INODE_ANOTHER_FILE,
+        location=test_location, parent=self._raw_path_spec)
+    file_entry = self._file_system.GetFileEntryByPathSpec(path_spec)
+    self.assertIsNotNone(file_entry)
+
+    stat_object = file_entry._GetStat()
+
+    self.assertIsNotNone(stat_object)
+    self.assertEqual(stat_object.type, stat_object.TYPE_FILE)
+    self.assertEqual(stat_object.size, 22)
+
+    self.assertEqual(stat_object.mode, 436)
+    self.assertEqual(stat_object.uid, 1000)
+    self.assertEqual(stat_object.gid, 1000)
+
+    self.assertEqual(stat_object.atime, 1567246979)
+    self.assertFalse(hasattr(stat_object, 'atime_nano'))
+
+    self.assertEqual(stat_object.ctime, 1567246979)
+    self.assertFalse(hasattr(stat_object, 'ctime_nano'))
+
+    self.assertFalse(hasattr(stat_object, 'crtime'))
+
+    self.assertEqual(stat_object.mtime, 1567246979)
+    self.assertFalse(hasattr(stat_object, 'mtime_nano'))
+
+  def testGetStatAttribute(self):
+    """Tests the _GetStatAttribute function."""
+    test_location = '/a_directory/another_file'
+    path_spec = path_spec_factory.Factory.NewPathSpec(
+        definitions.TYPE_INDICATOR_EXT, inode=self._INODE_ANOTHER_FILE,
+        location=test_location, parent=self._raw_path_spec)
+    file_entry = self._file_system.GetFileEntryByPathSpec(path_spec)
+    self.assertIsNotNone(file_entry)
+
+    stat_attribute = file_entry._GetStatAttribute()
+
+    self.assertIsNotNone(stat_attribute)
+    self.assertEqual(stat_attribute.group_identifier, 1000)
+    self.assertEqual(stat_attribute.inode_number, 15)
+    self.assertEqual(stat_attribute.mode, 0o664)
+    self.assertEqual(stat_attribute.number_of_links, 1)
+    self.assertEqual(stat_attribute.owner_identifier, 1000)
+    self.assertEqual(stat_attribute.size, 22)
+    self.assertEqual(stat_attribute.type, stat_attribute.TYPE_FILE)
+
   def testGetFileEntryByPathSpec(self):
     """Tests the GetFileEntryByPathSpec function."""
     path_spec = path_spec_factory.Factory.NewPathSpec(
@@ -136,36 +216,6 @@ def testGetParentFileEntry(self):
 
     self.assertEqual(parent_file_entry.name, 'a_directory')
 
-  def testGetStat(self):
-    """Tests the GetStat function."""
-    test_location = '/a_directory/another_file'
-    path_spec = path_spec_factory.Factory.NewPathSpec(
-        definitions.TYPE_INDICATOR_EXT, inode=self._INODE_ANOTHER_FILE,
-        location=test_location, parent=self._raw_path_spec)
-    file_entry = self._file_system.GetFileEntryByPathSpec(path_spec)
-    self.assertIsNotNone(file_entry)
-
-    stat_object = file_entry.GetStat()
-
-    self.assertIsNotNone(stat_object)
-    self.assertEqual(stat_object.type, stat_object.TYPE_FILE)
-    self.assertEqual(stat_object.size, 22)
-
-    self.assertEqual(stat_object.mode, 436)
-    self.assertEqual(stat_object.uid, 1000)
-    self.assertEqual(stat_object.gid, 1000)
-
-    self.assertEqual(stat_object.atime, 1567246979)
-    self.assertFalse(hasattr(stat_object, 'atime_nano'))
-
-    self.assertEqual(stat_object.ctime, 1567246979)
-    self.assertFalse(hasattr(stat_object, 'ctime_nano'))
-
-    self.assertFalse(hasattr(stat_object, 'crtime'))
-
-    self.assertEqual(stat_object.mtime, 1567246979)
-    self.assertFalse(hasattr(stat_object, 'mtime_nano'))
-
   def testIsFunctions(self):
     """Tests the Is? functions."""
     test_location = '/a_directory/another_file'