fail2ban/fail2ban/client/jailreader.py

286 lines
9.1 KiB
Python

# emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: t -*-
# vi: set ft=python sts=4 ts=4 sw=4 noet :
# This file is part of Fail2Ban.
#
# Fail2Ban is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# Fail2Ban is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Fail2Ban; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
# Author: Cyril Jaquier
#
__author__ = "Cyril Jaquier"
__copyright__ = "Copyright (c) 2004 Cyril Jaquier"
__license__ = "GPL"
import glob
import json
import os.path
import re
from .configreader import ConfigReaderUnshared, ConfigReader
from .filterreader import FilterReader
from .actionreader import ActionReader
from ..version import version
from ..helpers import getLogger
from ..helpers import splitwords
# Gets the instance of the logger.
logSys = getLogger(__name__)
class JailReader(ConfigReader):
# regex, to extract list of options:
optionCRE = re.compile(r"^([^\[]+)(?:\[(.*)\])?\s*$", re.DOTALL)
# regex, to iterate over single option in option list, syntax:
# `action = act[p1="...", p2='...', p3=...]`, where the p3=... not contains `,` or ']'
# since v0.10 separator extended with `]\s*[` for support of multiple option groups, syntax
# `action = act[p1=...][p2=...]`
optionExtractRE = re.compile(
r'([\w\-_\.]+)=(?:"([^"]*)"|\'([^\']*)\'|([^,\]]*))(?:,|\]\s*\[|$)', re.DOTALL)
def __init__(self, name, force_enable=False, **kwargs):
ConfigReader.__init__(self, **kwargs)
self.__name = name
self.__filter = None
self.__force_enable = force_enable
self.__actions = list()
self.__opts = None
@property
def options(self):
return self.__opts
def setName(self, value):
self.__name = value
def getName(self):
return self.__name
def read(self):
out = ConfigReader.read(self, "jail")
# Before returning -- verify that requested section
# exists at all
if not (self.__name in self.sections()):
raise ValueError("Jail %r was not found among available"
% self.__name)
return out
def isEnabled(self):
return self.__force_enable or (
self.__opts and self.__opts.get("enabled", False))
@staticmethod
def _glob(path):
"""Given a path for glob return list of files to be passed to server.
Dangling symlinks are warned about and not returned
"""
pathList = []
for p in glob.glob(path):
if os.path.exists(p):
pathList.append(p)
else:
logSys.warning("File %s is a dangling link, thus cannot be monitored" % p)
return pathList
def getOptions(self):
opts1st = [["bool", "enabled", False],
["string", "filter", ""]]
opts = [["bool", "enabled", False],
["string", "logpath", None],
["string", "logencoding", None],
["string", "backend", "auto"],
["int", "maxretry", None],
["string", "findtime", None],
["string", "bantime", None],
["string", "usedns", None], # be sure usedns is before all regex(s) in stream
["string", "failregex", None],
["string", "ignoreregex", None],
["string", "ignorecommand", None],
["bool", "ignoreself", None],
["string", "ignoreip", None],
["string", "filter", ""],
["string", "datepattern", None],
["string", "action", ""]]
# Before interpolation (substitution) add static options always available as default:
defsec = self._cfg.get_defaults()
defsec["fail2ban_version"] = version
try:
# Read first options only needed for merge defaults ('known/...' from filter):
self.__opts = ConfigReader.getOptions(self, self.__name, opts1st, shouldExist=True)
if not self.__opts: # pragma: no cover
raise JailDefError("Init jail options failed")
if not self.isEnabled():
return True
# Read filter
flt = self.__opts["filter"]
if flt:
filterName, filterOpt = JailReader.extractOptions(flt)
if not filterName:
raise JailDefError("Invalid filter definition %r" % flt)
self.__filter = FilterReader(
filterName, self.__name, filterOpt,
share_config=self.share_config, basedir=self.getBaseDir())
ret = self.__filter.read()
if not ret:
raise JailDefError("Unable to read the filter %r" % filterName)
# merge options from filter as 'known/...' (all options unfiltered):
self.__filter.getOptions(self.__opts, all=True)
ConfigReader.merge_section(self, self.__name, self.__filter.getCombined(), 'known/')
else:
self.__filter = None
logSys.warning("No filter set for jail %s" % self.__name)
# Read second all options (so variables like %(known/param) can be interpolated):
self.__opts = ConfigReader.getOptions(self, self.__name, opts)
if not self.__opts: # pragma: no cover
raise JailDefError("Read jail options failed")
# cumulate filter options again (ignore given in jail):
if self.__filter:
self.__filter.getOptions(self.__opts)
# Read action
for act in self.__opts["action"].split('\n'):
try:
if not act: # skip empty actions
continue
actName, actOpt = JailReader.extractOptions(act)
if not actName:
raise JailDefError("Invalid action definition %r" % act)
if actName.endswith(".py"):
self.__actions.append([
"set",
self.__name,
"addaction",
actOpt.pop("actname", os.path.splitext(actName)[0]),
os.path.join(
self.getBaseDir(), "action.d", actName),
json.dumps(actOpt),
])
else:
action = ActionReader(
actName, self.__name, actOpt,
share_config=self.share_config, basedir=self.getBaseDir())
ret = action.read()
if ret:
action.getOptions(self.__opts)
self.__actions.append(action)
else:
raise JailDefError("Unable to read action %r" % actName)
except JailDefError:
raise
except Exception as e:
logSys.debug("Caught exception: %s", e, exc_info=True)
raise ValueError("Error in action definition %r: %r" % (act, e))
if not len(self.__actions):
logSys.warning("No actions were defined for %s" % self.__name)
except JailDefError as e:
e = str(e)
logSys.error(e)
if not self.__opts:
self.__opts = dict()
self.__opts['config-error'] = e
return False
return True
def convert(self, allow_no_files=False):
"""Convert read before __opts to the commands stream
Parameters
----------
allow_missing : bool
Either to allow log files to be missing entirely. Primarily is
used for testing
"""
stream = []
e = self.__opts.get('config-error')
if e:
stream.extend([['config-error', "Jail '%s' skipped, because of wrong configuration: %s" % (self.__name, e)]])
return stream
if self.__filter:
stream.extend(self.__filter.convert())
for opt, value in self.__opts.iteritems():
if opt == "logpath":
if self.__opts.get('backend', None).startswith("systemd"): continue
found_files = 0
for path in value.split("\n"):
path = path.rsplit(" ", 1)
path, tail = path if len(path) > 1 else (path[0], "head")
pathList = JailReader._glob(path)
if len(pathList) == 0:
logSys.error("No file(s) found for glob %s" % path)
for p in pathList:
found_files += 1
stream.append(
["set", self.__name, "addlogpath", p, tail])
if not (found_files or allow_no_files):
raise ValueError(
"Have not found any log file for %s jail" % self.__name)
elif opt == "logencoding":
stream.append(["set", self.__name, "logencoding", value])
elif opt == "backend":
backend = value
elif opt == "ignoreip":
for ip in splitwords(value):
stream.append(["set", self.__name, "addignoreip", ip])
elif opt in ("failregex", "ignoreregex"):
multi = []
for regex in value.split('\n'):
# Do not send a command if the rule is empty.
if regex != '':
multi.append(regex)
if len(multi) > 1:
stream.append(["multi-set", self.__name, "add" + opt, multi])
elif len(multi):
stream.append(["set", self.__name, "add" + opt, multi[0]])
elif opt not in ('action', 'filter', 'enabled'):
stream.append(["set", self.__name, opt, value])
for action in self.__actions:
if isinstance(action, (ConfigReaderUnshared, ConfigReader)):
stream.extend(action.convert())
else:
stream.append(action)
stream.insert(0, ["add", self.__name, backend])
return stream
@staticmethod
def extractOptions(option):
match = JailReader.optionCRE.match(option)
if not match:
# TODO proper error handling
return None, None
option_name, optstr = match.groups()
option_opts = dict()
if optstr:
for optmatch in JailReader.optionExtractRE.finditer(optstr):
opt = optmatch.group(1)
value = [
val for val in optmatch.group(2,3,4) if val is not None][0]
option_opts[opt.strip()] = value.strip()
return option_name, option_opts
class JailDefError(Exception):
pass