Merge pull request #25 from leeclemens/enh/pyinotify

ENH: pyinotify

MANIFEST

@@ -20,6 +20,7 @@ client/configurator.py
 client/csocket.py
 server/asyncserver.py
 server/filter.py
+server/filterpyinotify.py
 server/filtergamin.py
 server/filterpoll.py
 server/iso8601.py

README

@@ -22,6 +22,11 @@ Required:
    >=python-2.3 (http://www.python.org)
 
 Optional:
+   pyinotify:
+      >=linux-2.6.13
+      >=python-2.4
+      >=pyinotify-0.8.3 (https://github.com/seb-m/pyinotify)
+   Gamin:
       >=gamin-0.0.21 (http://www.gnome.org/~veillard/gamin)
 
 To install, just do:

TODO

@@ -19,8 +19,6 @@ Legend:
 
 - Add timeout to external commands (signal alarm, watchdog thread, etc)
 
-- New backend: pyinotify
-
 - Uniformize filters and actions name. Use the software name (openssh, postfix,
   proftp)
 
@@ -52,3 +50,5 @@ Legend:
 # better return values in function
 
 # refactoring in server.py, actions.py, filter.py
+
+* New backend: pyinotify

config/jail.conf

@@ -25,14 +25,17 @@ findtime  = 600
 # "maxretry" is the number of failures before a host get banned.
 maxretry = 3
 
-# "backend" specifies the backend used to get files modification. Available
-# options are "gamin", "polling" and "auto". This option can be overridden in
-# each jail too (use "gamin" for a jail and "polling" for another).
+# "backend" specifies the backend used to get files modification.
+# Available options are "pyinotify", "gamin", "polling" and "auto".
+# This option can be overridden in each jail as well.
 #
-# gamin:   requires Gamin (a file alteration monitor) to be installed. If Gamin
-#          is not installed, Fail2ban will use polling.
+# pyinotify: requires pyinotify (a file alteration monitor) to be installed.
+#              If pyinotify is not installed, Fail2ban will use auto.
+# gamin:     requires Gamin (a file alteration monitor) to be installed.
+#              If Gamin is not installed, Fail2ban will use auto.
 # polling:   uses a polling algorithm which does not require external libraries.
-# auto:    will choose Gamin if available and polling otherwise.
+# auto:      will try to use the following backends, in order:
+#              pyinotify, gamin, polling.
 backend = auto
 
 

server/filterpyinotify.py

@@ -0,0 +1,155 @@
+# 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.
+
+# Original 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"
+
+from failmanager import FailManagerEmpty
+from filter import FileFilter
+from mytime import MyTime
+
+import time, logging, pyinotify
+
+# 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 instantiated by
+# a Jail object.
+
+class FilterPyinotify(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
+		# Pyinotify watch manager
+		self.__monitor = pyinotify.WatchManager()
+		self.__watches = dict()
+		logSys.debug("Created FilterPyinotify")
+
+
+	def callback(self, path):
+		self.getFailures(path)
+		try:
+			while True:
+				ticket = self.failManager.toBan()
+				self.jail.putFailTicket(ticket)
+		except FailManagerEmpty:
+			self.failManager.cleanup(MyTime.time())
+		self.dateDetector.sortTemplate()
+		self.__modified = False
+
+	##
+	# Add a log file path
+	#
+	# @param path log file path
+
+	def addLogPath(self, path, tail=False):
+		if self.containsLogPath(path):
+			logSys.error(path + " already exists")
+		else:
+			wd = self.__monitor.add_watch(path, pyinotify.IN_MODIFY)
+			self.__watches.update(wd)
+			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:
+			wdInt = self.__watches[path]
+			wd = self.__monitor.rm_watch(wdInt)
+			if wd[wdInt]:
+				del self.__watches[path]
+				FileFilter.delLogPath(self, path)
+				logSys.info("Removed logfile = %s" % path)
+			else:
+				logSys.error("Failed to remove watch on path: %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)
+		self.__notifier = pyinotify.ThreadedNotifier(self.__monitor,
+			ProcessPyinotify(self))
+		self.__notifier.start()
+		while self._isActive():
+			if not self.getIdle():
+				self.__notifier.process_events()
+				if self.__notifier.check_events():
+					self.__notifier.read_events()
+			else:
+				time.sleep(self.getSleepTime())
+		# Cleanup pyinotify
+		self.__cleanup()
+		logSys.debug(self.jail.getName() + ": filter terminated")
+		return True
+
+	##
+	# Call super.stop() and then stop the 'Notifier'
+
+	def stop(self):
+		# Call super to set __isRunning
+		super(FilterPyinotify, self).stop()
+		# Now stop the Notifier, otherwise we're deadlocked
+		self.__notifier.stop()
+
+	##
+	# Deallocates the resources used by pyinotify.
+
+	def __cleanup(self):
+		del self.__notifier
+		del self.__monitor
+
+
+class ProcessPyinotify(pyinotify.ProcessEvent):
+	def __init__(self, FileFilter, **kargs):
+		#super(ProcessPyinotify, self).__init__(**kargs)
+		# for some reason root class _ProcessEvent is old-style (is
+		# not derived from object), so to play safe let's avoid super
+		# for now, and call superclass directly
+		pyinotify.ProcessEvent.__init__(self, **kargs)
+		self.__FileFilter = FileFilter
+		pass
+
+	# just need default, since using mask on watch to limit events
+	def process_default(self, event):
+		logSys.debug("Callback for Event: %s" % event)
+		self.__FileFilter.callback(event.pathname)

server/jail.py

@@ -18,13 +18,9 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 # Author: Cyril Jaquier
-# 
-# $Revision$
 
-__author__ = "Cyril Jaquier"
-__version__ = "$Revision$"
-__date__ = "$Date$"
-__copyright__ = "Copyright (c) 2004 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
@@ -36,32 +32,65 @@ logSys = logging.getLogger("fail2ban.jail")
 
 class Jail:
 
+	#Known backends. Each backend should have corresponding __initBackend method
+	_BACKENDS = ('pyinotify', 'gamin', 'polling')
+
 	def __init__(self, name, backend = "auto"):
 		self.__name = name
 		self.__queue = Queue.Queue()
 		self.__filter = None
 		logSys.info("Creating new jail '%s'" % self.__name)
-		if backend == "polling":
-			self.__initPoller()
-		else:
-			try:
-				self.__initGamin()
-			except ImportError:
-				self.__initPoller()
-		self.__action = Actions(self)
+		self._setBackend(backend)
 
-	def __initPoller(self):
+	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):
+				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.__action = Actions(self)
+				return					# we are done
+			except ImportError, e:
+				logSys.debug(
+					"Backend %r failed to initialize due to %s" % (b, e))
+		raise RuntimeError(
+			"We should have initialized at least 'polling' backend")
+
+
+	def _initPoller(self):
 		logSys.info("Jail '%s' uses poller" % self.__name)
 		from filterpoll import FilterPoll
 		self.__filter = FilterPoll(self)
 	
-	def __initGamin(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 setName(self, name):
 		self.__name = name