From e442503133c86f5ef78dcc63cf1b90014213a22f Mon Sep 17 00:00:00 2001
From: Lee Clemens <java@leeclemens.net>
Date: Fri, 30 Dec 2011 00:18:52 -0500
Subject: [PATCH 01/14] Added pyinotify backend

---
 MANIFEST                  |   1 +
 config/jail.conf          |  17 +++--
 server/filterpyinotify.py | 148 ++++++++++++++++++++++++++++++++++++++
 server/jail.py            |  39 ++++++++--
 4 files changed, 194 insertions(+), 11 deletions(-)
 create mode 100644 server/filterpyinotify.py

diff --git a/MANIFEST b/MANIFEST
index 4c60f8e4..eef145b6 100644
--- a/MANIFEST
+++ b/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
diff --git a/config/jail.conf b/config/jail.conf
index fec6b1bd..cdef1cb3 100644
--- a/config/jail.conf
+++ b/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.
-# polling: uses a polling algorithm which does not require external libraries.
-# auto:    will choose Gamin if available and polling otherwise.
+# 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 try to use the following backends, in order:
+#              pyinotify, gamin, polling.
 backend = auto
 
 
diff --git a/server/filterpyinotify.py b/server/filterpyinotify.py
new file mode 100644
index 00000000..c5e70e22
--- /dev/null
+++ b/server/filterpyinotify.py
@@ -0,0 +1,148 @@
+# 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., 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 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 ProcessPyinotify(pyinotify.ProcessEvent):
+	def __init__(self, FileFilter, **kargs):
+		super(ProcessPyinotify, self).__init__(**kargs)
+		self.__FileFilter = FileFilter
+		pass
+
+	# just need default, since using mask on watch to limit events
+	def process_default(self, event):
+		logSys.debug("PYINOTIFY: Callback for Event: %s" % event)
+		self.__FileFilter.callback(event.pathname)
+
+
+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
+		self.monitor = pyinotify.WatchManager()
+		self.watches = dict()
+
+
+	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[path] = wd[path]
+			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.rm_watch(self.watches[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)
+		self.notifier = pyinotify.ThreadedNotifier(self.monitor,
+			ProcessPyinotify(self))
+		self.notifier.start()
+		while self._isActive():
+			if not self.getIdle():
+				self.notifier.process_events()
+				# Convert sleep seconds to millis
+				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
diff --git a/server/jail.py b/server/jail.py
index eefe69e5..16bdd088 100644
--- a/server/jail.py
+++ b/server/jail.py
@@ -41,13 +41,37 @@ class Jail:
 		self.__queue = Queue.Queue()
 		self.__filter = None
 		logSys.info("Creating new jail '%s'" % self.__name)
-		if backend == "polling":
-			self.__initPoller()
-		else:
+		self.__setBackend = False
+		if backend == "auto":
+			# Quick-escape for auto (default/fall-back condition)
+			self.__setBackend = False
+		elif backend == "pyinotify":
+			try:
+				self.__initPyinotify()
+				self.__setBackend = True
+			except ImportError:
+				self.__setBackend = False
+		elif backend == "gamin":
 			try:
 				self.__initGamin()
+				self.__setBackend = True
 			except ImportError:
-				self.__initPoller()
+				self.__setBackend = False
+		elif backend == "polling":
+			self.__initPoller()
+			self.__setBackend = True
+
+		if not self.__setBackend:
+			# If auto, or unrecognized, or failed using an explicit value
+			try:
+				self.__initPyinotify()
+			except ImportError:
+				try:
+					self.__initGamin()
+				except ImportError:
+					self.__initPoller()
+					self.__setBackend = True
+
 		self.__action = Actions(self)
 	
 	def __initPoller(self):
@@ -62,6 +86,13 @@ class Jail:
 		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
 	

From d1050350db96703cf15a36c99f842e45623d17e5 Mon Sep 17 00:00:00 2001
From: Lee Clemens <java@leeclemens.net>
Date: Fri, 30 Dec 2011 00:28:17 -0500
Subject: [PATCH 02/14] Added pyinotify backend

---
 server/filterpyinotify.py | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/server/filterpyinotify.py b/server/filterpyinotify.py
index c5e70e22..9b7a6f09 100644
--- a/server/filterpyinotify.py
+++ b/server/filterpyinotify.py
@@ -31,9 +31,7 @@ from failmanager import FailManagerEmpty
 from filter import FileFilter
 from mytime import MyTime
 
-import  time, logging, pyinotify
-
-
+import time, logging, pyinotify
 
 # Gets the instance of the logger.
 logSys = logging.getLogger("fail2ban.filter")
@@ -45,28 +43,19 @@ logSys = logging.getLogger("fail2ban.filter")
 # that matches a given regular expression. This class is instantiated by
 # a Jail object.
 
-class ProcessPyinotify(pyinotify.ProcessEvent):
-	def __init__(self, FileFilter, **kargs):
-		super(ProcessPyinotify, self).__init__(**kargs)
-		self.__FileFilter = FileFilter
-		pass
-
-	# just need default, since using mask on watch to limit events
-	def process_default(self, event):
-		logSys.debug("PYINOTIFY: Callback for Event: %s" % event)
-		self.__FileFilter.callback(event.pathname)
-
-
 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):
@@ -84,12 +73,12 @@ class FilterPyinotify(FileFilter):
 	# 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[path] = wd[path]
 			FileFilter.addLogPath(self, path, tail)
 			logSys.info("Added logfile = %s" % path)
 
@@ -102,7 +91,6 @@ class FilterPyinotify(FileFilter):
 		if not self.containsLogPath(path):
 			logSys.error(path + " is not monitored")
 		else:
-			self.monitor.rm_watch(self.watches[path])
 			FileFilter.delLogPath(self, path)
 			logSys.info("Removed logfile = %s" % path)
 
@@ -146,3 +134,15 @@ class FilterPyinotify(FileFilter):
 	def __cleanup(self):
 		del self.notifier
 		del self.monitor
+
+
+class ProcessPyinotify(pyinotify.ProcessEvent):
+	def __init__(self, FileFilter, **kargs):
+		super(ProcessPyinotify, self).__init__(**kargs)
+		self.__FileFilter = FileFilter
+		pass
+
+	# just need default, since using mask on watch to limit events
+	def process_default(self, event):
+		logSys.debug("PYINOTIFY: Callback for Event: %s" % event)
+		self.__FileFilter.callback(event.pathname)

From 4bf4d4ddb517a1980c72f2c2def3483d3cebe7d7 Mon Sep 17 00:00:00 2001
From: Lee Clemens <java@leeclemens.net>
Date: Fri, 30 Dec 2011 00:37:15 -0500
Subject: [PATCH 03/14] Removed wd assignment and irrelevant comment

---
 server/filterpyinotify.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/server/filterpyinotify.py b/server/filterpyinotify.py
index 9b7a6f09..12317687 100644
--- a/server/filterpyinotify.py
+++ b/server/filterpyinotify.py
@@ -78,7 +78,7 @@ class FilterPyinotify(FileFilter):
 		if self.containsLogPath(path):
 			logSys.error(path + " already exists")
 		else:
-			wd = self.monitor.add_watch(path, pyinotify.IN_MODIFY)
+			self.monitor.add_watch(path, pyinotify.IN_MODIFY)
 			FileFilter.addLogPath(self, path, tail)
 			logSys.info("Added logfile = %s" % path)
 
@@ -109,7 +109,6 @@ class FilterPyinotify(FileFilter):
 		while self._isActive():
 			if not self.getIdle():
 				self.notifier.process_events()
-				# Convert sleep seconds to millis
 				if self.notifier.check_events():
 					self.notifier.read_events()
 			else:

From adca2b87e8e1557bd0bc2dc6a5df78d2c98858d0 Mon Sep 17 00:00:00 2001
From: Lee Clemens <java@leeclemens.net>
Date: Fri, 30 Dec 2011 17:20:58 -0500
Subject: [PATCH 04/14] Changed Copyright information

---
 server/filterpyinotify.py | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/server/filterpyinotify.py b/server/filterpyinotify.py
index 12317687..1202eb41 100644
--- a/server/filterpyinotify.py
+++ b/server/filterpyinotify.py
@@ -18,13 +18,11 @@
 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 # Author: Cyril Jaquier
-#
-# $Revision$
 
-__author__ = "Cyril Jaquier"
+__author__ = "Lee Clemens"
 __version__ = "$Revision$"
 __date__ = "$Date$"
-__copyright__ = "Copyright (c) 2004 Cyril Jaquier"
+__copyright__ = "Copyright (c) 2011 Lee Clemens"
 __license__ = "GPL"
 
 from failmanager import FailManagerEmpty

From b0830385ed4e92fff7248cf664dbb02d576d2cef Mon Sep 17 00:00:00 2001
From: Lee Clemens <java@leeclemens.net>
Date: Sat, 31 Dec 2011 02:01:19 -0500
Subject: [PATCH 05/14] Update Free Software Foundation's address

---
 server/filterpyinotify.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/server/filterpyinotify.py b/server/filterpyinotify.py
index 1202eb41..11c5f911 100644
--- a/server/filterpyinotify.py
+++ b/server/filterpyinotify.py
@@ -15,7 +15,7 @@
 #
 # 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
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 # Author: Cyril Jaquier
 

From 4c130634980f2acc3b9d7352529d9f5a388435c1 Mon Sep 17 00:00:00 2001
From: Lee Clemens <java@leeclemens.net>
Date: Sat, 31 Dec 2011 03:33:58 -0500
Subject: [PATCH 06/14] Added addLogPath and delLogPath functionality
 (adds/removes paths from the WatchManager)

---
 server/filterpyinotify.py | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/server/filterpyinotify.py b/server/filterpyinotify.py
index 11c5f911..ec6f53da 100644
--- a/server/filterpyinotify.py
+++ b/server/filterpyinotify.py
@@ -54,6 +54,7 @@ class FilterPyinotify(FileFilter):
 		# Pyinotify watch manager
 		self.monitor = pyinotify.WatchManager()
 		logSys.debug("Created FilterPyinotify")
+		self.__watches = dict()
 
 
 	def callback(self, path):
@@ -76,7 +77,8 @@ class FilterPyinotify(FileFilter):
 		if self.containsLogPath(path):
 			logSys.error(path + " already exists")
 		else:
-			self.monitor.add_watch(path, pyinotify.IN_MODIFY)
+			wd = self.monitor.add_watch(path, pyinotify.IN_MODIFY)
+			self.__watches.update(wd)
 			FileFilter.addLogPath(self, path, tail)
 			logSys.info("Added logfile = %s" % path)
 
@@ -89,8 +91,14 @@ class FilterPyinotify(FileFilter):
 		if not self.containsLogPath(path):
 			logSys.error(path + " is not monitored")
 		else:
-			FileFilter.delLogPath(self, path)
-			logSys.info("Removed logfile = %s" % path)
+			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.

From 5c4ec6e7fb83022d7305c7fa83a71c2a637421e9 Mon Sep 17 00:00:00 2001
From: Lee Clemens <java@leeclemens.net>
Date: Sat, 31 Dec 2011 03:37:43 -0500
Subject: [PATCH 07/14] Renamed Notifier and Watch Manager to start with __
 prefix

---
 server/filterpyinotify.py | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/server/filterpyinotify.py b/server/filterpyinotify.py
index ec6f53da..c5ca6b99 100644
--- a/server/filterpyinotify.py
+++ b/server/filterpyinotify.py
@@ -52,7 +52,7 @@ class FilterPyinotify(FileFilter):
 		FileFilter.__init__(self, jail)
 		self.__modified = False
 		# Pyinotify watch manager
-		self.monitor = pyinotify.WatchManager()
+		self.__monitor = pyinotify.WatchManager()
 		logSys.debug("Created FilterPyinotify")
 		self.__watches = dict()
 
@@ -77,7 +77,7 @@ class FilterPyinotify(FileFilter):
 		if self.containsLogPath(path):
 			logSys.error(path + " already exists")
 		else:
-			wd = self.monitor.add_watch(path, pyinotify.IN_MODIFY)
+			wd = self.__monitor.add_watch(path, pyinotify.IN_MODIFY)
 			self.__watches.update(wd)
 			FileFilter.addLogPath(self, path, tail)
 			logSys.info("Added logfile = %s" % path)
@@ -92,7 +92,7 @@ class FilterPyinotify(FileFilter):
 			logSys.error(path + " is not monitored")
 		else:
 			wdInt = self.__watches[path]
-			wd = self.monitor.rm_watch(wdInt)
+			wd = self.__monitor.rm_watch(wdInt)
 			if wd[wdInt]:
 				del self.__watches[path]
 				FileFilter.delLogPath(self, path)
@@ -109,14 +109,14 @@ class FilterPyinotify(FileFilter):
 
 	def run(self):
 		self.setActive(True)
-		self.notifier = pyinotify.ThreadedNotifier(self.monitor,
+		self.__notifier = pyinotify.ThreadedNotifier(self.__monitor,
 			ProcessPyinotify(self))
-		self.notifier.start()
+		self.__notifier.start()
 		while self._isActive():
 			if not self.getIdle():
-				self.notifier.process_events()
-				if self.notifier.check_events():
-					self.notifier.read_events()
+				self.__notifier.process_events()
+				if self.__notifier.check_events():
+					self.__notifier.read_events()
 			else:
 				time.sleep(self.getSleepTime())
 		# Cleanup pyinotify
@@ -131,14 +131,14 @@ class FilterPyinotify(FileFilter):
 		# Call super to set __isRunning
 		super(FilterPyinotify, self).stop()
 		# Now stop the Notifier, otherwise we're deadlocked
-		self.notifier.stop()
+		self.__notifier.stop()
 
 	##
 	# Deallocates the resources used by pyinotify.
 
 	def __cleanup(self):
-		del self.notifier
-		del self.monitor
+		del self.__notifier
+		del self.__monitor
 
 
 class ProcessPyinotify(pyinotify.ProcessEvent):

From aa4514bffa36d296de0f9dd8dfc9193e178d33d4 Mon Sep 17 00:00:00 2001
From: Lee Clemens <java@leeclemens.net>
Date: Sat, 31 Dec 2011 03:39:25 -0500
Subject: [PATCH 08/14] Removed PYINOTIFY prefix to debug statement for
 Callback for Event

---
 server/filterpyinotify.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/server/filterpyinotify.py b/server/filterpyinotify.py
index c5ca6b99..94e2328c 100644
--- a/server/filterpyinotify.py
+++ b/server/filterpyinotify.py
@@ -149,5 +149,5 @@ class ProcessPyinotify(pyinotify.ProcessEvent):
 
 	# just need default, since using mask on watch to limit events
 	def process_default(self, event):
-		logSys.debug("PYINOTIFY: Callback for Event: %s" % event)
+		logSys.debug("Callback for Event: %s" % event)
 		self.__FileFilter.callback(event.pathname)

From 02894623cfcabef6773051ab43bd6ba10b2b351c Mon Sep 17 00:00:00 2001
From: Lee Clemens <java@leeclemens.net>
Date: Tue, 3 Jan 2012 20:14:24 -0500
Subject: [PATCH 09/14] Moved dict() above debug statement

---
 server/filterpyinotify.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/server/filterpyinotify.py b/server/filterpyinotify.py
index 94e2328c..2f466960 100644
--- a/server/filterpyinotify.py
+++ b/server/filterpyinotify.py
@@ -53,8 +53,8 @@ class FilterPyinotify(FileFilter):
 		self.__modified = False
 		# Pyinotify watch manager
 		self.__monitor = pyinotify.WatchManager()
-		logSys.debug("Created FilterPyinotify")
 		self.__watches = dict()
+		logSys.debug("Created FilterPyinotify")
 
 
 	def callback(self, path):

From c9945db756f974a446a6d759cfe2fd92086b2cff Mon Sep 17 00:00:00 2001
From: Lee Clemens <java@leeclemens.net>
Date: Tue, 3 Jan 2012 21:30:55 -0500
Subject: [PATCH 10/14] Updated TODO

---
 TODO | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/TODO b/TODO
index 2b17c916..ce40ebcf 100644
--- a/TODO
+++ b/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

From f9ccc0543f674dd5ab0ca362bfe41fb660396833 Mon Sep 17 00:00:00 2001
From: Lee Clemens <java@leeclemens.net>
Date: Sun, 8 Jan 2012 14:27:00 -0500
Subject: [PATCH 11/14] Added pyinotify requirements to README

---
 README | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/README b/README
index 4b5048ed..556e2fac 100644
--- a/README
+++ b/README
@@ -22,7 +22,12 @@ Required:
    >=python-2.3 (http://www.python.org)
 
 Optional:
-   >=gamin-0.0.21 (http://www.gnome.org/~veillard/gamin)
+   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:
 

From 7413817f9acb239c2e4fd088d7a35d7819c8998f Mon Sep 17 00:00:00 2001
From: Yaroslav Halchenko <debian@onerussian.com>
Date: Sun, 8 Jan 2012 21:27:12 -0500
Subject: [PATCH 12/14] RF: for pyinotify's filter -- adjusted
 authors/copyright and avoided super() for old-style class

---
 server/filterpyinotify.py | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/server/filterpyinotify.py b/server/filterpyinotify.py
index 2f466960..66d43e53 100644
--- a/server/filterpyinotify.py
+++ b/server/filterpyinotify.py
@@ -17,12 +17,10 @@
 # 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
+# Original author: Cyril Jaquier
 
-__author__ = "Lee Clemens"
-__version__ = "$Revision$"
-__date__ = "$Date$"
-__copyright__ = "Copyright (c) 2011 Lee Clemens"
+__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
@@ -143,7 +141,11 @@ class FilterPyinotify(FileFilter):
 
 class ProcessPyinotify(pyinotify.ProcessEvent):
 	def __init__(self, FileFilter, **kargs):
-		super(ProcessPyinotify, self).__init__(**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
 

From f90d53fc2616d38b7ee2d65ba13ee7c0f1463b0c Mon Sep 17 00:00:00 2001
From: Yaroslav Halchenko <debian@onerussian.com>
Date: Sun, 8 Jan 2012 21:29:43 -0500
Subject: [PATCH 13/14] RF: traverse known backends in a loop

should now be
- easier to comprehend
- more scalable happens new backends come
- more informative with all the info and debug messages

NB not sure why __setBackend was instance's attribute, now there is a
   method _setBackend
---
 server/jail.py | 82 +++++++++++++++++++++++++-------------------------
 1 file changed, 41 insertions(+), 41 deletions(-)

diff --git a/server/jail.py b/server/jail.py
index ff7f4e25..4307db78 100644
--- a/server/jail.py
+++ b/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 Celemens, Yaroslav Halchenko"
+__copyright__ = "Copyright (c) 2004 Cyril Jaquier, 2011-2012 Lee Clemens, 2012 Yaroslav Halchenko"
 __license__ = "GPL"
 
 import Queue, logging
@@ -35,58 +31,62 @@ from actions import Actions
 logSys = logging.getLogger("fail2ban.jail")
 
 class Jail:
-	
+
+	_BACKENDS = ('pyinotify', 'gamin', 'pull')
+	"""Known backends.  Each backend should have corresponding
+	__initBackend method
+	"""
+
 	def __init__(self, name, backend = "auto"):
 		self.__name = name
 		self.__queue = Queue.Queue()
 		self.__filter = None
 		logSys.info("Creating new jail '%s'" % self.__name)
-		self.__setBackend = False
-		if backend == "auto":
-			# Quick-escape for auto (default/fall-back condition)
-			self.__setBackend = False
-		elif backend == "pyinotify":
-			try:
-				self.__initPyinotify()
-				self.__setBackend = True
-			except ImportError:
-				self.__setBackend = False
-		elif backend == "gamin":
-			try:
-				self.__initGamin()
-				self.__setBackend = True
-			except ImportError:
-				self.__setBackend = False
-		elif backend == "polling":
-			self.__initPoller()
-			self.__setBackend = True
+		self._setBackend(backend)
 
-		if not self.__setBackend:
-			# If auto, or unrecognized, or failed using an explicit value
-			try:
-				self.__initPyinotify()
-			except ImportError:
-				try:
-					self.__initGamin()
-				except ImportError:
-					self.__initPoller()
-					self.__setBackend = True
+	def _setBackend(self, backend):
+		backend = backend.lower()		# to assure consistent matching
 
-		self.__action = Actions(self)
-	
-	def __initPoller(self):
+		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):
+	def _initPyinotify(self):
 		# Try to import pyinotify
 		import pyinotify
 		logSys.info("Jail '%s' uses pyinotify" % self.__name)

From b7adb290887644a23927d5ffd27bf34ef2ba0d1a Mon Sep 17 00:00:00 2001
From: Lee Clemens <java@leeclemens.net>
Date: Mon, 9 Jan 2012 19:30:49 -0500
Subject: [PATCH 14/14] Spelling, Changed docstring to comment

---
 server/jail.py | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/server/jail.py b/server/jail.py
index 4307db78..dd179a30 100644
--- a/server/jail.py
+++ b/server/jail.py
@@ -19,7 +19,7 @@
 
 # Author: Cyril Jaquier
 
-__author__ = "Cyril Jaquier, Lee Celemens, Yaroslav Halchenko"
+__author__ = "Cyril Jaquier, Lee Clemens, Yaroslav Halchenko"
 __copyright__ = "Copyright (c) 2004 Cyril Jaquier, 2011-2012 Lee Clemens, 2012 Yaroslav Halchenko"
 __license__ = "GPL"
 
@@ -32,10 +32,8 @@ logSys = logging.getLogger("fail2ban.jail")
 
 class Jail:
 
-	_BACKENDS = ('pyinotify', 'gamin', 'pull')
-	"""Known backends.  Each backend should have corresponding
-	__initBackend method
-	"""
+	#Known backends. Each backend should have corresponding __initBackend method
+	_BACKENDS = ('pyinotify', 'gamin', 'polling')
 
 	def __init__(self, name, backend = "auto"):
 		self.__name = name