# -*- coding: utf-8 -*-
"""Text parser plugin for Debian package manager log (dpkg.log) files.
An example:
2016-08-03 15:25:53 install base-passwd:amd64 <none> 3.5.33
Log messages are of the form:
YYYY-MM-DD HH:MM:SS startup type command
Where type is:
archives (with a command of unpack or install)
packages (with a command of configure, triggers-only, remove or purge)
YYYY-MM-DD HH:MM:SS status state pkg installed-version
YYYY-MM-DD HH:MM:SS action pkg installed-version available-version
Where action is:
install, upgrade, configure, trigproc, disappear, remove or purge.
YYYY-MM-DD HH:MM:SS conffile filename decision
Where decision is install or keep.
"""
import pyparsing
from dfdatetime import time_elements as dfdatetime_time_elements
from plaso.containers import events
from plaso.lib import errors
from plaso.parsers import text_parser
from plaso.parsers.text_plugins import interface
[docs]class DpkgEventData(events.EventData):
"""Dpkg event data.
Attributes:
added_time (dfdatetime.DateTimeValues): date and time the log entry
was added.
body (str): body of the log line.
"""
DATA_TYPE = 'linux:dpkg_log:entry'
def __init__(self):
"""Initializes event data."""
super(DpkgEventData, self).__init__(data_type=self.DATA_TYPE)
self.added_time = None
self.body = None
[docs]class DpkgTextPlugin(interface.TextPlugin):
"""Text parser plugin for Debian package manager log (dpkg.log) files."""
NAME = 'dpkg'
DATA_FORMAT = 'Debian package manager log (dpkg.log) file'
ENCODING = 'utf-8'
_TWO_DIGITS = pyparsing.Word(pyparsing.nums, exact=2).setParseAction(
lambda tokens: int(tokens[0], 10))
_FOUR_DIGITS = pyparsing.Word(pyparsing.nums, exact=4).setParseAction(
lambda tokens: int(tokens[0], 10))
_DATE_TIME = pyparsing.Group(
_FOUR_DIGITS + pyparsing.Suppress('-') +
_TWO_DIGITS + pyparsing.Suppress('-') +
_TWO_DIGITS +
_TWO_DIGITS + pyparsing.Suppress(':') +
_TWO_DIGITS + pyparsing.Suppress(':') +
_TWO_DIGITS).setResultsName('date_time')
_DPKG_STARTUP_TYPE = pyparsing.oneOf([
'archives',
'packages'])
_DPKG_STARTUP_COMMAND = pyparsing.oneOf([
'unpack',
'install',
'configure',
'triggers-only',
'remove',
'purge'])
_DPKG_STARTUP_BODY = pyparsing.Combine((
pyparsing.Literal('startup') + _DPKG_STARTUP_TYPE +
_DPKG_STARTUP_COMMAND), joinString=' ', adjacent=False)
_DPKG_STATUS_BODY = pyparsing.Combine((
pyparsing.Literal('status') + pyparsing.Word(pyparsing.printables) +
pyparsing.Word(pyparsing.printables) +
pyparsing.Word(pyparsing.printables)), joinString=' ', adjacent=False)
_DPKG_ACTION = pyparsing.oneOf([
'install',
'upgrade',
'configure',
'trigproc',
'disappear',
'remove',
'purge'])
_DPKG_ACTION_BODY = pyparsing.Combine((
_DPKG_ACTION + pyparsing.Word(pyparsing.printables) +
pyparsing.Word(pyparsing.printables) +
pyparsing.Word(pyparsing.printables)), joinString=' ', adjacent=False)
_DPKG_CONFFILE_DECISION = pyparsing.oneOf([
'install',
'keep'])
_DPKG_CONFFILE_BODY = pyparsing.Combine((
pyparsing.Literal('conffile') + pyparsing.Word(pyparsing.printables) +
_DPKG_CONFFILE_DECISION), joinString=' ', adjacent=False)
_END_OF_LINE = pyparsing.Suppress(pyparsing.LineEnd())
_LOG_LINE = (_DATE_TIME + pyparsing.MatchFirst([
_DPKG_STARTUP_BODY, _DPKG_STATUS_BODY, _DPKG_ACTION_BODY,
_DPKG_CONFFILE_BODY]).setResultsName('body') +
_END_OF_LINE)
_LINE_STRUCTURES = [('log_line', _LOG_LINE)]
VERIFICATION_GRAMMAR = _LOG_LINE
VERIFICATION_LITERALS = [
' conffile ', ' configure ', ' disappear ', ' install ', ' purge ',
' remove ', ' startup ', ' status ', ' trigproc ', ' upgrade ']
def _ParseRecord(self, parser_mediator, key, structure):
"""Parses a pyparsing structure.
Args:
parser_mediator (ParserMediator): mediates interactions between parsers
and other components, such as storage and dfVFS.
key (str): name of the parsed structure.
structure (pyparsing.ParseResults): tokens from a parsed log line.
Raises:
ParseError: if the structure cannot be parsed.
"""
time_elements_structure = self._GetValueFromStructure(
structure, 'date_time')
event_data = DpkgEventData()
event_data.added_time = self._ParseTimeElements(time_elements_structure)
event_data.body = self._GetValueFromStructure(structure, 'body')
parser_mediator.ProduceEventData(event_data)
def _ParseTimeElements(self, time_elements_structure):
"""Parses date and time elements of a log line.
Args:
time_elements_structure (pyparsing.ParseResults): date and time elements
of a log line.
Returns:
dfdatetime.TimeElements: date and time value.
Raises:
ParseError: if a valid date and time value cannot be derived from
the time elements.
"""
try:
# Ensure time_elements_tuple is not a pyparsing.ParseResults otherwise
# copy.deepcopy() of the dfDateTime object will fail on Python 3.8 with:
# "TypeError: 'str' object is not callable" due to pyparsing.ParseResults
# overriding __getattr__ with a function that returns an empty string
# when named token does not exists.
year, month, day_of_month, hours, minutes, seconds = (
time_elements_structure)
date_time = dfdatetime_time_elements.TimeElements(time_elements_tuple=(
year, month, day_of_month, hours, minutes, seconds))
date_time.is_local_time = True
return date_time
except (TypeError, ValueError) as exception:
raise errors.ParseError(
'Unable to parse time elements with error: {0!s}'.format(exception))
[docs] def CheckRequiredFormat(self, parser_mediator, text_reader):
"""Check if the log record has the minimal structure required by the plugin.
Args:
parser_mediator (ParserMediator): mediates interactions between parsers
and other components, such as storage and dfVFS.
text_reader (EncodedTextReader): text reader.
Returns:
bool: True if this is the correct parser, False otherwise.
"""
try:
structure = self._VerifyString(text_reader.lines)
except errors.ParseError:
return False
time_elements_structure = self._GetValueFromStructure(
structure, 'date_time')
try:
self._ParseTimeElements(time_elements_structure)
except errors.ParseError:
return False
return True
text_parser.TextLogParser.RegisterPlugin(DpkgTextPlugin)