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fail2ban/server/server.py

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12 KiB

# 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
# Author: Cyril Jaquier
#
# $Revision$
__author__ = "Cyril Jaquier"
__version__ = "$Revision$"
__date__ = "$Date$"
__copyright__ = "Copyright (c) 2004 Cyril Jaquier"
__license__ = "GPL"
from threading import Lock, RLock
from jails import Jails
from transmitter import Transmitter
from ssocket import SSocket
from ssocket import SSocketErrorException
import logging, logging.handlers, sys, os, signal
# Gets the instance of the logger.
logSys = logging.getLogger("fail2ban.server")
class Server:
def __init__(self, daemon = False):
self.__loggingLock = Lock()
self.__lock = RLock()
self.__jails = Jails()
self.__daemon = daemon
self.__transm = Transmitter(self)
self.__socket = SSocket(self.__transm)
self.__logLevel = 3
self.__logTarget = "STDOUT"
# Set logging level
self.setLogLevel(self.__logLevel)
self.setLogTarget(self.__logTarget)
def __sigTERMhandler(self, signum, frame):
logSys.debug("Caught signal %d. Exiting" % signum)
self.quit()
def start(self, sock, force = False):
logSys.info("Starting Fail2ban")
# Install signal handlers
signal.signal(signal.SIGTERM, self.__sigTERMhandler)
signal.signal(signal.SIGINT, self.__sigTERMhandler)
# First set the mask to only allow access to owner
os.umask(0077)
if self.__daemon:
ret = self.__createDaemon()
if ret:
logSys.info("Daemon started")
else:
logSys.error("Could not create daemon")
raise ServerInitializationError("Could not create daemon")
# Start the communication
logSys.debug("Starting communication")
try:
self.__socket.initialize(sock, force)
self.__socket.start()
# Workaround (???) for join() bug.
# https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1167930&group_id=5470
while self.__socket.isAlive():
self.__socket.join(1)
except SSocketErrorException:
logSys.error("Could not start server")
logSys.info("Exiting Fail2ban")
def quit(self):
self.stopAllJail()
# Stop communication
self.__socket.stop()
def addJail(self, name, backend):
self.__jails.add(name, backend)
def delJail(self, name):
self.__jails.remove(name)
def startJail(self, name):
try:
self.__lock.acquire()
if not self.isActive(name):
self.__jails.get(name).start()
finally:
self.__lock.release()
def stopJail(self, name):
try:
self.__lock.acquire()
if self.isActive(name):
self.__jails.get(name).stop()
self.delJail(name)
finally:
self.__lock.release()
def stopAllJail(self):
try:
self.__lock.acquire()
for jail in self.__jails.getAll():
self.stopJail(jail)
finally:
self.__lock.release()
def isActive(self, name):
return self.__jails.get(name).isActive()
def setIdleJail(self, name, value):
self.__jails.get(name).setIdle(value)
return True
def getIdleJail(self, name):
return self.__jails.get(name).getIdle()
# Filter
def addIgnoreIP(self, name, ip):
self.__jails.getFilter(name).addIgnoreIP(ip)
def delIgnoreIP(self, name, ip):
self.__jails.getFilter(name).delIgnoreIP(ip)
def getIgnoreIP(self, name):
return self.__jails.getFilter(name).getIgnoreIP()
def addLogPath(self, name, fileName):
self.__jails.getFilter(name).addLogPath(fileName)
def delLogPath(self, name, fileName):
self.__jails.getFilter(name).delLogPath(fileName)
def getLogPath(self, name):
return self.__jails.getFilter(name).getLogPath()
def setTimeRegex(self, name, value):
self.__jails.getFilter(name).setTimeRegex(value)
def getTimeRegex(self, name):
return self.__jails.getFilter(name).getTimeRegex()
def setTimePattern(self, name, value):
self.__jails.getFilter(name).setTimePattern(value)
def getTimePattern(self, name):
return self.__jails.getFilter(name).getTimePattern()
def setFindTime(self, name, value):
self.__jails.getFilter(name).setFindTime(value)
def getFindTime(self, name):
return self.__jails.getFilter(name).getFindTime()
def addFailRegex(self, name, value):
self.__jails.getFilter(name).addFailRegex(value)
def delFailRegex(self, name, index):
self.__jails.getFilter(name).delFailRegex(index)
def getFailRegex(self, name):
return self.__jails.getFilter(name).getFailRegex()
def addIgnoreRegex(self, name, value):
self.__jails.getFilter(name).addIgnoreRegex(value)
def delIgnoreRegex(self, name, index):
self.__jails.getFilter(name).delIgnoreRegex(index)
def getIgnoreRegex(self, name):
return self.__jails.getFilter(name).getIgnoreRegex()
def setMaxRetry(self, name, value):
self.__jails.getFilter(name).setMaxRetry(value)
def getMaxRetry(self, name):
return self.__jails.getFilter(name).getMaxRetry()
# Action
def addAction(self, name, value):
self.__jails.getAction(name).addAction(value)
def getLastAction(self, name):
return self.__jails.getAction(name).getLastAction()
def delAction(self, name, value):
self.__jails.getAction(name).delAction(value)
def setCInfo(self, name, action, key, value):
self.__jails.getAction(name).getAction(action).setCInfo(key, value)
def getCInfo(self, name, action, key):
return self.__jails.getAction(name).getAction(action).getCInfo(key)
def delCInfo(self, name, action, key):
self.__jails.getAction(name).getAction(action).delCInfo(key)
def setBanTime(self, name, value):
self.__jails.getAction(name).setBanTime(value)
def getBanTime(self, name):
return self.__jails.getAction(name).getBanTime()
def setActionStart(self, name, action, value):
self.__jails.getAction(name).getAction(action).setActionStart(value)
def getActionStart(self, name, action):
return self.__jails.getAction(name).getAction(action).getActionStart()
def setActionStop(self, name, action, value):
self.__jails.getAction(name).getAction(action).setActionStop(value)
def getActionStop(self, name, action):
return self.__jails.getAction(name).getAction(action).getActionStop()
def setActionCheck(self, name, action, value):
self.__jails.getAction(name).getAction(action).setActionCheck(value)
def getActionCheck(self, name, action):
return self.__jails.getAction(name).getAction(action).getActionCheck()
def setActionBan(self, name, action, value):
self.__jails.getAction(name).getAction(action).setActionBan(value)
def getActionBan(self, name, action):
return self.__jails.getAction(name).getAction(action).getActionBan()
def setActionUnban(self, name, action, value):
self.__jails.getAction(name).getAction(action).setActionUnban(value)
def getActionUnban(self, name, action):
return self.__jails.getAction(name).getAction(action).getActionUnban()
# Status
def status(self):
try:
self.__lock.acquire()
jailList = ''
for jail in self.__jails.getAll():
jailList += jail + ', '
length = len(jailList)
if not length == 0:
jailList = jailList[:length-2]
ret = [("Number of jail", self.__jails.size()),
("Jail list", jailList)]
return ret
finally:
self.__lock.release()
def statusJail(self, name):
return self.__jails.get(name).getStatus()
# Logging
##
# Set the logging level.
#
# Incrementing the value gives more messages.
# 0 = FATAL
# 1 = ERROR
# 2 = WARNING
# 3 = INFO
# 4 = DEBUG
# @param value the level
def setLogLevel(self, value):
try:
self.__loggingLock.acquire()
self.__logLevel = value
logLevel = logging.DEBUG
if value == 0:
logLevel = logging.FATAL
elif value == 1:
logLevel = logging.ERROR
elif value == 2:
logLevel = logging.WARNING
elif value == 3:
logLevel = logging.INFO
logging.getLogger("fail2ban").setLevel(logLevel)
finally:
self.__loggingLock.release()
##
# Get the logging level.
#
# @see setLogLevel
# @return the log level
def getLogLevel(self):
try:
self.__loggingLock.acquire()
return self.__logLevel
finally:
self.__loggingLock.release()
##
# Sets the logging target.
#
# target can be a file, SYSLOG, STDOUT or STDERR.
# @param target the logging target
def setLogTarget(self, target):
try:
self.__loggingLock.acquire()
if target == "SYSLOG":
facility = logging.handlers.SysLogHandler.LOG_DAEMON
hdlr = logging.handlers.SysLogHandler("/dev/log",
facility = facility)
elif target == "STDOUT":
hdlr = logging.StreamHandler(sys.stdout)
elif target == "STDERR":
hdlr = logging.StreamHandler(sys.stderr)
else:
# Target should be a file
try:
open(target, "a")
hdlr = logging.FileHandler(target)
except IOError:
logSys.error("Unable to log to " + target)
logSys.info("Logging to previous target " + self.__logTarget)
return False
self.__logTarget = target
# Remove previous handler
logging.getLogger("fail2ban").handlers = []
# set a format which is simpler for console use
formatter = logging.Formatter("%(asctime)s %(name)-16s: %(levelname)-6s %(message)s")
# tell the handler to use this format
hdlr.setFormatter(formatter)
logging.getLogger("fail2ban").addHandler(hdlr)
return True
finally:
self.__loggingLock.release()
def getLogTarget(self):
try:
self.__loggingLock.acquire()
return self.__logTarget
finally:
self.__loggingLock.release()
def __createDaemon(self):
""" Detach a process from the controlling terminal and run it in the
background as a daemon.
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/278731
"""
try:
# Fork a child process so the parent can exit. This will return control
# to the command line or shell. This is required so that the new process
# is guaranteed not to be a process group leader. We have this guarantee
# because the process GID of the parent is inherited by the child, but
# the child gets a new PID, making it impossible for its PID to equal its
# PGID.
pid = os.fork()
except OSError, e:
return((e.errno, e.strerror)) # ERROR (return a tuple)
if pid == 0: # The first child.
# Next we call os.setsid() to become the session leader of this new
# session. The process also becomes the process group leader of the
# new process group. Since a controlling terminal is associated with a
# session, and this new session has not yet acquired a controlling
# terminal our process now has no controlling terminal. This shouldn't
# fail, since we're guaranteed that the child is not a process group
# leader.
os.setsid()
# When the first child terminates, all processes in the second child
# are sent a SIGHUP, so it's ignored.
signal.signal(signal.SIGHUP, signal.SIG_IGN)
try:
# Fork a second child to prevent zombies. Since the first child is
# a session leader without a controlling terminal, it's possible for
# it to acquire one by opening a terminal in the future. This second
# fork guarantees that the child is no longer a session leader, thus
# preventing the daemon from ever acquiring a controlling terminal.
pid = os.fork() # Fork a second child.
except OSError, e:
return((e.errno, e.strerror)) # ERROR (return a tuple)
if (pid == 0): # The second child.
# Ensure that the daemon doesn't keep any directory in use. Failure
# to do this could make a filesystem unmountable.
os.chdir("/")
else:
os._exit(0) # Exit parent (the first child) of the second child.
else:
os._exit(0) # Exit parent of the first child.
# Close all open files. Try the system configuration variable, SC_OPEN_MAX,
# for the maximum number of open files to close. If it doesn't exist, use
# the default value (configurable).
try:
maxfd = os.sysconf("SC_OPEN_MAX")
except (AttributeError, ValueError):
maxfd = 256 # default maximum
for fd in range(0, maxfd):
try:
os.close(fd)
except OSError: # ERROR (ignore)
pass
# Redirect the standard file descriptors to /dev/null.
os.open("/dev/null", os.O_RDONLY) # standard input (0)
os.open("/dev/null", os.O_RDWR) # standard output (1)
os.open("/dev/null", os.O_RDWR) # standard error (2)
return True
class ServerInitializationError(Exception):
pass