filtergamin.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: 697 $

__author__ = "Cyril Jaquier"
__version__ = "$Revision: 697 $"
__date__ = "$Date: 2008-05-19 23:08:36 +0200 (Mon, 19 May 2008) $"
__copyright__ = "Copyright (c) 2004 Cyril Jaquier"
__license__ = "GPL"

from failmanager import FailManagerEmpty
from filter import FileFilter
from mytime import MyTime

import time, logging, gamin

# Gets the instance of the logger.
logSys = logging.getLogger("fail2ban.filter")

##
# Log reader class.
#
# This class reads a log file and detects login failures or anything else
# that matches a given regular expression. This class is instanciated by
# a Jail object.

class FilterGamin(FileFilter):

    ##
    # Constructor.
    #
    # Initialize the filter object with default values.
    # @param jail the jail object
    
    def __init__(self, jail):
        FileFilter.__init__(self, jail)
        self.__modified = False
        # Gamin monitor
        self.monitor = gamin.WatchMonitor()
        logSys.debug("Created FilterGamin")


    def callback(self, path, event):
        logSys.debug("Got event: " + `event` + " for " + path)
        if event in (gamin.GAMCreated, gamin.GAMChanged, gamin.GAMExists):
            logSys.debug("File changed: " + path)
            self.getFailures(path)
            self.__modified = True


    ##
    # Add a log file path
    #
    # @param path log file path

    def addLogPath(self, path, tail = True):
        if self.containsLogPath(path):
            logSys.error(path + " already exists")
        else:
            self.monitor.watch_file(path, self.callback)
            FileFilter.addLogPath(self, path, tail)
            logSys.info("Added logfile = %s" % path)            
    
    ##
    # Delete a log path
    #
    # @param path the log file to delete
    
    def delLogPath(self, path):
        if not self.containsLogPath(path):
            logSys.error(path + " is not monitored")
        else:
            self.monitor.stop_watch(path)
            FileFilter.delLogPath(self, path)
            logSys.info("Removed logfile = %s" % path)
        
    ##
    # Main loop.
    #
    # This function is the main loop of the thread. It checks if the
    # file has been modified and looks for failures.
    # @return True when the thread exits nicely

    def run(self):
        self.setActive(True)
        while self._isActive():
            if not self.getIdle():
                # We cannot block here because we want to be able to
                # exit.
                if self.monitor.event_pending():
                    self.monitor.handle_events()

                if self.__modified:
                    try:
                        while True:
                            ticket = self.failManager.toBan()
                            self.jail.putFailTicket(ticket)
                    except FailManagerEmpty:
                        self.failManager.cleanup(MyTime.time())
                    self.__modified = False
                time.sleep(self.getSleepTime())
            else:
                time.sleep(self.getSleepTime())
        # Cleanup Gamin
        self.__cleanup()
        logSys.debug(self.jail.getName() + ": filter terminated")
        return True

    ##
    # Desallocates the resources used by Gamin.

    def __cleanup(self):
        for path in self.getLogPath():
            self.monitor.stop_watch(path.getFileName())
        del self.monitor