From 96c3b06abbb11f7eb8735acd7741d62854e425ba Mon Sep 17 00:00:00 2001
From: sebres <serg.brester@sebres.de>
Date: Fri, 19 May 2017 13:25:49 +0200
Subject: [PATCH] amend to #1778: repair notifier wait-cycle (too long timeout
 in polling, too late check for pending files, too long stop)

---
 fail2ban/server/filterpyinotify.py | 32 ++++++++++++++++++++----------
 fail2ban/tests/filtertestcase.py   |  1 +
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/fail2ban/server/filterpyinotify.py b/fail2ban/server/filterpyinotify.py
index 71540f3c..53f2cbda 100644
--- a/fail2ban/server/filterpyinotify.py
+++ b/fail2ban/server/filterpyinotify.py
@@ -82,7 +82,7 @@ class FilterPyinotify(FileFilter):
 		self.__watchDirs = dict()
 		self.__pending = dict()
 		self.__pendingChkTime = 0
-		self.__pendingNextTime = 0
+		self.__pendingMinTime = 60
 		logSys.debug("Created FilterPyinotify")
 
 	def callback(self, event, origin=''):
@@ -150,7 +150,7 @@ class FilterPyinotify(FileFilter):
 	def _addPending(self, path, reason, isDir=False):
 		if path not in self.__pending:
 			self.__pending[path] = [Utils.DEFAULT_SLEEP_INTERVAL, isDir];
-			self.__pendingNextTime = 0
+			self.__pendingMinTime = 0
 			if isinstance(reason, pyinotify.Event):
 				reason = [reason.maskname, reason.pathname]
 			logSys.log(logging.MSG, "Log absence detected (possibly rotation) for %s, reason: %s of %s",
@@ -165,7 +165,7 @@ class FilterPyinotify(FileFilter):
 		if not self.__pending:
 			return
 		ntm = time.time()
-		if ntm < self.__pendingNextTime:
+		if ntm < self.__pendingChkTime + self.__pendingMinTime:
 			return
 		found = {}
 		minTime = 60
@@ -187,7 +187,7 @@ class FilterPyinotify(FileFilter):
 				del self.__pending[path]
 			except KeyError: pass
 		self.__pendingChkTime = time.time()
-		self.__pendingNextTime = self.__pendingChkTime + minTime
+		self.__pendingMinTime = minTime
 		# process now because we've missed it in monitoring:
 		for path, isDir in found.iteritems():
 			# refresh monitoring of this:
@@ -295,6 +295,12 @@ class FilterPyinotify(FileFilter):
 			self.commonError()
 		self.ticks += 1
 
+	@property
+	def __notify_maxtout(self):
+		# timeout for pyinotify must be set in milliseconds (fail2ban time values are 
+		# floats contain seconds), max 0.5 sec (additionally regards pending check time)
+		return min(self.sleeptime, 0.5, self.__pendingMinTime) * 1000
+
 	##
 	# Main loop.
 	#
@@ -304,9 +310,8 @@ class FilterPyinotify(FileFilter):
 	def run(self):
 		prcevent = pyinotify.ProcessEvent()
 		prcevent.process_default = self.__process_default
-		## timeout for pyinotify must be set in milliseconds (our time values are floats contain seconds)
 		self.__notifier = pyinotify.Notifier(self.__monitor,
-			prcevent, timeout=self.sleeptime * 1000)
+			prcevent, timeout=self.__notify_maxtout)
 		logSys.debug("[%s] filter started (pyinotifier)", self.jailName)
 		while self.active:
 			try:
@@ -314,13 +319,19 @@ class FilterPyinotify(FileFilter):
 				# slow check events while idle:
 				if self.idle:
 					if Utils.wait_for(lambda: not self.active or not self.idle,
-						self.sleeptime * 10, self.sleeptime
+						min(self.sleeptime * 10, self.__pendingMinTime), 
+						min(self.sleeptime, self.__pendingMinTime)
 					):
 						if not self.active: break
 
 				# default pyinotify handling using Notifier:
 				self.__notifier.process_events()
-				if Utils.wait_for(lambda: not self.active or self.__notifier.check_events(), self.sleeptime):
+
+				# wait for events / timeout:
+				notify_maxtout = self.__notify_maxtout
+				def __check_events():
+					return not self.active or self.__notifier.check_events(timeout=notify_maxtout)
+				if Utils.wait_for(__check_events, min(self.sleeptime, self.__pendingMinTime)):
 					if not self.active: break
 					self.__notifier.read_events()
 
@@ -347,11 +358,10 @@ class FilterPyinotify(FileFilter):
 	# Call super.stop() and then stop the 'Notifier'
 
 	def stop(self):
-		if self.__notifier: # stop the notifier
-			self.__notifier.stop()
 		# stop filter thread:
 		super(FilterPyinotify, self).stop()
-		self.join()
+		if self.__notifier: # stop the notifier
+			self.__notifier.stop()
 
 	##
 	# Wait for exit with cleanup.
diff --git a/fail2ban/tests/filtertestcase.py b/fail2ban/tests/filtertestcase.py
index ec2dea89..20a7ad50 100644
--- a/fail2ban/tests/filtertestcase.py
+++ b/fail2ban/tests/filtertestcase.py
@@ -996,6 +996,7 @@ def get_monitor_failures_testcase(Filter_):
 			self._wait4failures(2)
 			# stop before tmpdir deleted (just prevents many monitor events)
 			self.filter.stop()
+			self.filter.join()
 
 
 		def _test_move_into_file(self, interim_kill=False):