fail2ban/server/action.py

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# 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: 556 $
__author__ = "Cyril Jaquier"
__version__ = "$Revision: 556 $"
__date__ = "$Date: 2007-03-07 21:54:32 +0100 (Wed, 07 Mar 2007) $"
__copyright__ = "Copyright (c) 2004 Cyril Jaquier"
__license__ = "GPL"
import logging, os
#from subprocess import call
# Gets the instance of the logger.
logSys = logging.getLogger("fail2ban.actions.action")
##
# Execute commands.
#
# This class reads the failures from the Jail queue and decide if an
# action has to be taken. A BanManager take care of the banned IP
# addresses.
class Action:
def __init__(self, name):
self.__name = name
self.__cInfo = dict()
## Command executed in order to initialize the system.
self.__actionStart = ''
## Command executed when an IP address gets banned.
self.__actionBan = ''
## Command executed when an IP address gets removed.
self.__actionUnban = ''
## Command executed in order to check requirements.
self.__actionCheck = ''
## Command executed in order to stop the system.
self.__actionStop = ''
logSys.debug("Created Action")
##
# Sets the action name.
#
# @param name the name of the action
def setName(self, name):
self.__name = name
##
# Returns the action name.
#
# @return the name of the action
def getName(self):
return self.__name
##
# Sets a "CInfo".
#
# CInfo are statically defined properties. They can be definied by
# the user and are used to set e-mail addresses, port, host or
# anything that should not change during the life of the server.
#
# @param key the property name
# @param value the property value
def setCInfo(self, key, value):
self.__cInfo[key] = value
##
# Returns a "CInfo".
#
# @param key the property name
def getCInfo(self, key):
return self.__cInfo[key]
##
# Removes a "CInfo".
#
# @param key the property name
def delCInfo(self, key):
del self.__cInfo[key]
##
# Set the "start" command.
#
# @param value the command
def setActionStart(self, value):
self.__actionStart = value
logSys.info("Set actionStart = %s" % value)
##
# Get the "start" command.
#
# @return the command
def getActionStart(self):
return self.__actionStart
##
# Executes the action "start" command.
#
# Replaces the tags in the action command with value of "cInfo"
# and executes the resulting command.
#
# @return True if the command succeeded
def execActionStart(self):
startCmd = Action.replaceTag(self.__actionStart, self.__cInfo)
return Action.executeCmd(startCmd)
##
# Set the "ban" command.
#
# @param value the command
def setActionBan(self, value):
self.__actionBan = value
logSys.info("Set actionBan = %s" % value)
##
# Get the "ban" command.
#
# @return the command
def getActionBan(self):
return self.__actionBan
##
# Executes the action "ban" command.
#
# @return True if the command succeeded
def execActionBan(self, aInfo):
return self.__processCmd(self.__actionBan, aInfo)
##
# Set the "unban" command.
#
# @param value the command
def setActionUnban(self, value):
self.__actionUnban = value
logSys.info("Set actionUnban = %s" % value)
##
# Get the "unban" command.
#
# @return the command
def getActionUnban(self):
return self.__actionUnban
##
# Executes the action "unban" command.
#
# @return True if the command succeeded
def execActionUnban(self, aInfo):
return self.__processCmd(self.__actionUnban, aInfo)
##
# Set the "check" command.
#
# @param value the command
def setActionCheck(self, value):
self.__actionCheck = value
logSys.info("Set actionCheck = %s" % value)
##
# Get the "check" command.
#
# @return the command
def getActionCheck(self):
return self.__actionCheck
##
# Set the "stop" command.
#
# @param value the command
def setActionStop(self, value):
self.__actionStop = value
logSys.info("Set actionStop = %s" % value)
##
# Get the "stop" command.
#
# @return the command
def getActionStop(self):
return self.__actionStop
##
# Executes the action "stop" command.
#
# Replaces the tags in the action command with value of "cInfo"
# and executes the resulting command.
#
# @return True if the command succeeded
def execActionStop(self):
stopCmd = Action.replaceTag(self.__actionStop, self.__cInfo)
return Action.executeCmd(stopCmd)
##
# Replaces tags in query with property values in aInfo.
#
# @param query the query string with tags
# @param aInfo the properties
# @return a string
@staticmethod
def replaceTag(query, aInfo):
""" Replace tags in query
"""
string = query
for tag in aInfo:
string = string.replace('<' + tag + '>', str(aInfo[tag]))
# New line
string = string.replace("<br>", '\n')
return string
##
# Executes a command with preliminary checks and substitutions.
#
# Before executing any commands, executes the "check" command first
# in order to check if prerequirements are met. If this check fails,
# it tries to restore a sane environnement before executing the real
# command.
# Replaces "aInfo" and "cInfo" in the query too.
#
# @param cmd The command to execute
# @param aInfo Dynamic properties
# @return True if the command succeeded
def __processCmd(self, cmd, aInfo = None):
""" Executes an OS command.
"""
if cmd == "":
logSys.debug("Nothing to do")
return True
checkCmd = Action.replaceTag(self.__actionCheck, self.__cInfo)
if not Action.executeCmd(checkCmd):
logSys.error("Invariant check failed. Trying to restore a sane" +
" environment")
stopCmd = Action.replaceTag(self.__actionStop, self.__cInfo)
Action.executeCmd(stopCmd)
startCmd = Action.replaceTag(self.__actionStart, self.__cInfo)
Action.executeCmd(startCmd)
if not Action.executeCmd(checkCmd):
logSys.fatal("Unable to restore environment")
return False
# Replace tags
if not aInfo == None:
realCmd = Action.replaceTag(cmd, aInfo)
else:
realCmd = cmd
# Replace static fields
realCmd = Action.replaceTag(realCmd, self.__cInfo)
return Action.executeCmd(realCmd)
##
# Executes a command.
#
# We need a shell here because commands are mainly shell script. They
# contain pipe, redirection, etc.
#
# @todo Force the use of bash!?
# @todo Kill the command after a given timeout
#
# @param realCmd the command to execute
# @return True if the command succeeded
@staticmethod
def executeCmd(realCmd):
logSys.debug(realCmd)
try:
# The following line gives deadlock with multiple jails
#retcode = call(realCmd, shell=True)
retcode = os.system(realCmd)
if retcode == 0:
logSys.debug("%s returned successfully" % realCmd)
return True
else:
logSys.error("%s returned %x" % (realCmd, retcode))
except OSError, e:
logSys.error("%s failed with %s" % (realCmd, e))
return False