"""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"
[docs]
def __init__(self):
"""Initializes event data."""
super().__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"
# Date and time values are formatted as:
# 2009-02-25 11:45:23
_DATE_TIME = pyparsing.Regex(
r"(?P<date_time>[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}) "
)
_DPKG_STARTUP_TYPE = pyparsing.one_of(["archives", "packages"])
_DPKG_STARTUP_COMMAND = pyparsing.one_of(
["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.one_of(
["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.one_of(["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,
]
).set_results_name("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:
date_time = dfdatetime_time_elements.TimeElements()
date_time.CopyFromDateTimeString(time_elements_structure)
# APT History logs store date and time values in local time.
date_time.is_local_time = True
# TODO: remove this after updating dfDateTime not to set the time zone in
# CopyFromDateTimeString for a time string without time zone information.
date_time.time_zone_offset = None
return date_time
except (IndexError, TypeError, ValueError) as exception:
raise errors.ParseError(
f"Unable to parse time elements with error: {exception!s}"
)
[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 plugin, 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)