simplifying logic and shortening messages (delta in minutes; removed clock synchronization, because it is rarely an issue on fail2ban side, e. g. for remote logs only, etc)

fail2ban/server/filter.py

@@ -655,45 +655,34 @@ class Filter(JailThread):
 					tupleLine = ("", self.__lastTimeText, line)
 					date = self.__lastDate
 		
-		if self.checkFindTime:
+		if self.checkFindTime and date is not None:
 			# if in operation (modifications have been really found):
 			if self.inOperation:
 				# if weird date - we'd simulate now for timeing issue (too large deviation from now):
-				delta = date - MyTime.time()
-				if (date is None or abs(delta) > 60):
-					latency = "This could indicate a latency problem."
-					synchronization = "This could be a clock synchronization" + \
-						" problem; are you sure that NTP is set up?"
-					timezone = "This looks like a timezone problem."
-					msg = ""
-					if -15*60 <= delta <= 0:
-						msg = latency
-					elif 0 < delta <= 15*60:
-						msg = synchronization
-					else:
-						msg = timezone
-					# log time zone issue as warning once per day:
+				delta = int(date - MyTime.time())
+				if abs(delta) > 60:
+					delta /= 60
+					# log timing issue as warning once per day:
 					self._logWarnOnce("_next_simByTimeWarn",
-						("Found a log entry with a timestamp %ss %s the current time. %s",
-						 abs(delta),
-						 "before" if delta <= 0 else "after",
-						 msg),
-						("Please check this jail and associated logs as there" +
-						 " is potentially a timezone or latency problem: %s",
+						("Detected a log entry %sm %s the current time in operation mode. "
+						 "This looks like a %s problem. Treating such entries as if they just happened.",
+						 abs(delta), "before" if delta < 0 else "after",
+						 "latency" if -55 <= delta < 0 else "timezone"
+						 ),
+						("Please check a jail for a timing issue. Line with odd timestamp: %s",
 						 line))
 					# simulate now as date:
 					date = MyTime.time()
 					self.__lastDate = date
 			else:
 				# in initialization (restore) phase, if too old - ignore:
-				if date is not None and date < MyTime.time() - self.getFindTime():
+				if date < MyTime.time() - self.getFindTime():
 					# log time zone issue as warning once per day:
 					self._logWarnOnce("_next_ignByTimeWarn",
-						("Ignoring all log entries older than %s; these are probably" +
+						("Ignoring all log entries older than %ss; these are probably" +
 						 " messages generated while fail2ban was not running.",
 							self.getFindTime()),
-						("Please check this jail and associated logs as" +
-						 " there is potentially a timezone or latency problem: %s",
+						("Please check a jail for a timing issue. Line with odd timestamp: %s",
 						 line))
 					# ignore - too old (obsolete) entry:
 					return []

fail2ban/tests/filtertestcase.py

@@ -444,11 +444,11 @@ class IgnoreIP(LogCaptureTestCase):
 	def testTimeJump_InOperation(self):
 		self._testTimeJump(inOperation=True)
 
-	def testWrongTimeZone(self):
+	def testWrongTimeOrTZ(self):
 		try:
 			self.filter.addFailRegex('fail from <ADDR>$')
 			self.filter.setDatePattern(r'{^LN-BEG}%Y-%m-%d %H:%M:%S(?:\s*%Z)?\s')
-			self.filter.setMaxRetry(5); # don't ban here
+			self.filter.setMaxRetry(50); # don't ban here
 			self.filter.inOperation = True; # real processing (all messages are new)
 			# current time is 1h later than log-entries:
 			MyTime.setTime(1572138000+3600)
@@ -476,36 +476,29 @@ class IgnoreIP(LogCaptureTestCase):
 				"Match without a timestamp:",
 				"192.0.2.17:1", "192.0.2.17:2", "192.0.2.17:3",
 				"Total # of detected failures: 9.", all=True, wait=True)
-		finally:
-			tearDownMyTime()
-
-	def testWrongTimeDelta(self):
-		try:
-			self.filter.addFailRegex('fail from <ADDR>$')
-			self.filter.setDatePattern(r'{^LN-BEG}%Y-%m-%d %H:%M:%S(?:\s*%Z)?\s')
-			self.filter.setMaxRetry(5); # don't ban here
-			self.filter.inOperation = True; # real processing (all messages are new)
-			expectable_messages = ["timezone problem.", "clock synchronization problem;", "latency problem."]
-			cases = [(-90*60, 0),
-				 (-10*60, 1),
-				 (-30, None),
-				 (30, None),
-				 (10*60, 2),
-				 (90*60, 0)]
-			for idx, (delta, expect) in enumerate(cases):
+			#
+			phase = 3
+			for delta, expect in (
+				(-90*60, "timezone"), #90 minutes after
+				(-60*60, "timezone"), #60 minutes after
+				(-10*60, "timezone"), #10 minutes after
+				(-59,    None),       #59 seconds after
+				(59,     None),       #59 seconds before
+				(61,     "latency"),  #>1 minute before
+				(55*60,  "latency"),  #55 minutes before
+				(90*60,  "timezone")  #90 minutes before
+			):
+				phase += 1
 				MyTime.setTime(1572138000+delta)
 				setattr(self.filter, "_next_simByTimeWarn", -1)
-				self.pruneLog('[phase {phase}] log entries offset by {delta}s'.format(phase=idx+1, delta=delta))
-				for i in (1,2,3):
+				self.pruneLog('[phase {phase}] log entries offset by {delta}s'.format(phase=phase, delta=delta))
 				self.filter.processLineAndAdd('2019-10-27 02:00:00 fail from 192.0.2.15');
-				for (idx, msg) in enumerate(expectable_messages):
-					if idx == expect:
-						self.assertLogged(expectable_messages[idx])
+				self.assertLogged("Found 192.0.2.15", wait=True)
+				if expect:
+					self.assertLogged(("timezone problem", "latency problem")[int(expect == "latency")], all=True)
+					self.assertNotLogged(("timezone problem", "latency problem")[int(expect != "latency")])
 				else:
-						self.assertNotLogged(expectable_messages[idx])
-				self.assertLogged(
-					"192.0.2.15:1", "192.0.2.15:2", "192.0.2.15:3",
-					"Total # of detected failures: 3.", wait=True)
+					self.assertNotLogged("timezone problem", "latency problem", all=True)
 		finally:
 			tearDownMyTime()