Source code for plaso.parsers.fseventsd

# -*- coding: utf-8 -*-
"""Parsers for MacOS fseventsd files.

Also see:

import os

from dfvfs.resolver import resolver as path_spec_resolver

from plaso.containers import events
from plaso.lib import dtfabric_helper
from plaso.lib import errors
from plaso.lib import specification
from plaso.parsers import interface
from plaso.parsers import manager

[docs] class FseventsdEventData(events.EventData): """MacOS file system event (fseventsd) event data. Attributes: event_identifier (int): the record event identifier. file_entry_modification_time (dfdatetime.DateTimeValues): file entry last modification date and time. flags (int): flags stored in the record. node_identifier (int): file system node identifier related to the file system event. path (str): path recorded in the fseventsd record. """ DATA_TYPE = 'macos:fseventsd:record'
[docs] def __init__(self): """Initializes an Fseventsd event data.""" super(FseventsdEventData, self).__init__(data_type=self.DATA_TYPE) self.event_identifier = None self.file_entry_modification_time = None self.flags = None self.node_identifier = None self.path = None
[docs] class FseventsdParser( interface.FileObjectParser, dtfabric_helper.DtFabricHelper): """Parser for fseventsd files. This parser supports both version 1 and version 2 fseventsd files. """ NAME = 'fseventsd' DATA_FORMAT = 'MacOS File System Events Disk Log Stream (fseventsd) file' # The version 1 format was used in Mac OS X 10.5 (Leopard) through macOS 10.12 # (Sierra). _DLS_V1_SIGNATURE = b'1SLD' # The version 2 format was introduced in MacOS High Sierra (10.13). _DLS_V2_SIGNATURE = b'2SLD' _DEFINITION_FILE = os.path.join( os.path.dirname(__file__), 'fseventsd.yaml')
[docs] @classmethod def GetFormatSpecification(cls): """Retrieves the format specification. Returns: FormatSpecification: format specification. """ format_specification = specification.FormatSpecification(cls.NAME) format_specification.AddNewSignature(cls._DLS_V1_SIGNATURE, offset=0) format_specification.AddNewSignature(cls._DLS_V2_SIGNATURE, offset=0) return format_specification
def _ParseDLSPageHeader(self, file_object, page_offset): """Parses a DLS page header from a file-like object. Args: file_object (file): file-like object to read the header from. page_offset (int): offset of the start of the page header, relative to the start of the file. Returns: tuple: containing: dls_page_header: parsed record structure. int: header size. Raises: ParseError: when the header cannot be parsed. """ page_header_map = self._GetDataTypeMap('dls_page_header') try: page_header, page_size = self._ReadStructureFromFileObject( file_object, page_offset, page_header_map) except (ValueError, errors.ParseError) as exception: raise errors.ParseError( 'Unable to parse page header at offset: 0x{0:08x} ' 'with error: {1!s}'.format(page_offset, exception)) return page_header, page_size def _BuildEventData(self, record): """Builds an FseventsdData object from a parsed structure. Args: record (dls_record_v1|dls_record_v2): parsed record structure. Returns: FseventsdEventData: event data attribute container. """ event_data = FseventsdEventData() event_data.path = record.path event_data.flags = record.event_flags event_data.event_identifier = record.event_identifier # Node identifier is only set in DLS V2 records. event_data.node_identifier = getattr(record, 'node_identifier', None) return event_data def _GetParentModificationTime(self, gzip_file_entry): """Retrieves the modification time of the file entry's parent file. Note that this retrieves the time from the file entry of the parent of the gzip file entry's path spec, which is different from trying to retrieve it from the gzip file entry's parent file entry. It would be preferable to retrieve the modification time from the metadata in the gzip file itself, but it appears to not be set when the file is written by fseventsd. Args: gzip_file_entry (dfvfs.FileEntry): file entry of the gzip file containing the fseventsd data. Returns: dfdatetime.DateTimeValues: parent modification time, or None if not available. """ parent_file_entry = path_spec_resolver.Resolver.OpenFileEntry( gzip_file_entry.path_spec.parent) if not parent_file_entry: return None return parent_file_entry.modification_time
[docs] def ParseFileObject(self, parser_mediator, file_object): """Parses an fseventsd file. Args: parser_mediator (ParserMediator): parser mediator. file_object (dfvfs.FileIO): a file-like object. Raises: WrongParser: when the header cannot be parsed. """ page_header_map = self._GetDataTypeMap('dls_page_header') try: page_header, file_offset = self._ReadStructureFromFileObject( file_object, 0, page_header_map) except (ValueError, errors.ParseError) as exception: raise errors.WrongParser( 'Unable to parse page header with error: {0!s}'.format( exception)) current_page_end = page_header.page_size file_entry = parser_mediator.GetFileEntry() date_time = self._GetParentModificationTime(file_entry) file_size = file_object.get_size() while file_offset < file_size: if file_offset >= current_page_end: try: page_header, header_size = self._ParseDLSPageHeader( file_object, file_offset) except errors.ParseError as exception: parser_mediator.ProduceExtractionWarning( 'Unable to parse page header with error: {0!s}'.format( exception)) break current_page_end += page_header.page_size file_offset += header_size continue if page_header.signature == self._DLS_V1_SIGNATURE: record_map = self._GetDataTypeMap('dls_record_v1') else: record_map = self._GetDataTypeMap('dls_record_v2') try: record, record_length = self._ReadStructureFromFileObject( file_object, file_offset, record_map) file_offset += record_length except (ValueError, errors.ParseError) as exception: parser_mediator.ProduceExtractionWarning( 'Unable to parse page record with error: {0!s}'.format( exception)) break event_data = self._BuildEventData(record) event_data.file_entry_modification_time = date_time parser_mediator.ProduceEventData(event_data)