fail2ban/fail2ban/server/jail.py

233 lines
6.5 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, Lee Clemens, Yaroslav Halchenko"
__copyright__ = "Copyright (c) 2004 Cyril Jaquier, 2011-2012 Lee Clemens, 2012 Yaroslav Halchenko"
__license__ = "GPL"
import Queue, logging
from .actions import Actions
# Gets the instance of the logger.
logSys = logging.getLogger(__name__)
class Jail:
"""Fail2Ban jail, which manages a filter and associated actions.
The class handles the initialisation of a filter, and actions. It's
role is then to act as an interface between the filter and actions,
passing bans detected by the filter, for the actions to then act upon.
Parameters
----------
name : str
Name assigned to the jail.
backend : str
Backend to be used for filter. "auto" will attempt to pick
the most preferred backend method. Default: "auto"
db : Fail2BanDb
Fail2Ban persistent database instance. Default: `None`
Attributes
----------
name
database
filter
actions
idle
status
"""
#Known backends. Each backend should have corresponding __initBackend method
# yoh: stored in a list instead of a tuple since only
# list had .index until 2.6
_BACKENDS = ['pyinotify', 'gamin', 'polling', 'systemd']
def __init__(self, name, backend = "auto", db=None):
self.__db = db
# 26 based on iptable chain name limit of 30 less len('f2b-')
if len(name) >= 26:
logSys.warning("Jail name %r might be too long and some commands "
"might not function correctly. Please shorten"
% name)
self.__name = name
self.__queue = Queue.Queue()
self.__filter = None
logSys.info("Creating new jail '%s'" % self.name)
self._setBackend(backend)
def __repr__(self):
return "%s(%r)" % (self.__class__.__name__, self.name)
def _setBackend(self, backend):
backend = backend.lower() # to assure consistent matching
backends = self._BACKENDS
if backend != 'auto':
# we have got strict specification of the backend to use
if not (backend in self._BACKENDS):
logSys.error("Unknown backend %s. Must be among %s or 'auto'"
% (backend, backends))
raise ValueError("Unknown backend %s. Must be among %s or 'auto'"
% (backend, backends))
# so explore starting from it till the 'end'
backends = backends[backends.index(backend):]
for b in backends:
initmethod = getattr(self, '_init%s' % b.capitalize())
try:
initmethod()
if backend != 'auto' and b != backend:
logSys.warning("Could only initiated %r backend whenever "
"%r was requested" % (b, backend))
else:
logSys.info("Initiated %r backend" % b)
self.__actions = Actions(self)
return # we are done
except ImportError, e:
logSys.debug(
"Backend %r failed to initialize due to %s" % (b, e))
# log error since runtime error message isn't printed, INVALID COMMAND
logSys.error(
"Failed to initialize any backend for Jail %r" % self.name)
raise RuntimeError(
"Failed to initialize any backend for Jail %r" % self.name)
def _initPolling(self):
logSys.info("Jail '%s' uses poller" % self.name)
from filterpoll import FilterPoll
self.__filter = FilterPoll(self)
def _initGamin(self):
# Try to import gamin
import gamin
logSys.info("Jail '%s' uses Gamin" % self.name)
from filtergamin import FilterGamin
self.__filter = FilterGamin(self)
def _initPyinotify(self):
# Try to import pyinotify
import pyinotify
logSys.info("Jail '%s' uses pyinotify" % self.name)
from filterpyinotify import FilterPyinotify
self.__filter = FilterPyinotify(self)
def _initSystemd(self): # pragma: systemd no cover
# Try to import systemd
import systemd
logSys.info("Jail '%s' uses systemd" % self.name)
from filtersystemd import FilterSystemd
self.__filter = FilterSystemd(self)
@property
def name(self):
"""Name of jail.
"""
return self.__name
@property
def database(self):
"""The database used to store persistent data for the jail.
"""
return self.__db
@property
def filter(self):
"""The filter which the jail is using to monitor log files.
"""
return self.__filter
@property
def actions(self):
"""Actions object used to manage actions for jail.
"""
return self.__actions
@property
def idle(self):
"""A boolean indicating whether jail is idle.
"""
return self.filter.idle or self.actions.idle
@idle.setter
def idle(self, value):
self.filter.idle = value
self.actions.idle = value
@property
def status(self):
"""The status of the jail.
"""
return [
("Filter", self.filter.status),
("Actions", self.actions.status),
]
def putFailTicket(self, ticket):
"""Add a fail ticket to the jail.
Used by filter to add a failure for banning.
"""
self.__queue.put(ticket)
if self.database is not None:
self.database.addBan(self, ticket)
def getFailTicket(self):
"""Get a fail ticket from the jail.
Used by actions to get a failure for banning.
"""
try:
return self.__queue.get(False)
except Queue.Empty:
return False
def start(self):
"""Start the jail, by starting filter and actions threads.
Once stated, also queries the persistent database to reinstate
any valid bans.
"""
self.filter.start()
self.actions.start()
# Restore any previous valid bans from the database
if self.database is not None:
for ticket in self.database.getBans(
jail=self, bantime=self.actions.getBanTime()):
self.__queue.put(ticket)
logSys.info("Jail '%s' started" % self.name)
def stop(self):
"""Stop the jail, by stopping filter and actions threads.
"""
self.filter.stop()
self.actions.stop()
self.filter.join()
self.actions.join()
logSys.info("Jail '%s' stopped" % self.name)
def is_alive(self):
"""Check jail "is_alive" by checking filter and actions threads.
"""
return self.filter.is_alive() or self.actions.is_alive()