actions: bug fix in lambdas in checkBan, because getBansMerged could return None (purge resp. asynchronous addBan), make the logic all around more stable;

test cases: extended with test to check action together with database functionality (ex.: to verify lambdas in checkBan);
database: getBansMerged should work within lock, using reentrant lock (cause call of getBans inside of getBansMerged);

2 files changed, 84 insertions, 44 deletions

diff --git a/fail2ban/server/actions.py b/fail2ban/server/actions.py
index c8e9c5d9..a36802bc 100644
--- a/fail2ban/server/actions.py
+++ b/fail2ban/server/actions.py
@@ -243,6 +243,44 @@ class Actions(JailThread, Mapping):
 		logSys.debug(self._jail.name + ": action terminated")
 		return True
 
+	def __getBansMerged(self, mi, idx):
+		"""Helper for lamda to get bans merged once
+
+		This function never returns None for ainfo lambdas - always a ticket (merged or single one)
+		and prevents any errors through merging (to guarantee ban actions will be executed).
+		[TODO] move merging to observer - here we could wait for merge and read already merged info from a database
+
+		Parameters
+		----------
+		mi : dict
+			initial for lambda should contains {ip, ticket}
+		idx : str
+			key to get a merged bans :
+			'all' - bans merged for all jails
+			'jail' - bans merged for current jail only
+
+		Returns
+		-------
+		BanTicket 
+			merged or self ticket only
+		"""
+		if idx in mi:
+			return mi[idx] if mi[idx] is not None else mi['ticket']
+		try:
+			jail=self._jail
+			ip=mi['ip']
+			mi[idx] = None
+			if idx == 'all':
+				mi[idx] = jail.database.getBansMerged(ip=ip)
+			elif idx == 'jail':
+				mi[idx] = jail.database.getBansMerged(ip=ip, jail=jail)
+		except Exception as e:
+			logSys.error(
+				"Failed to get %s bans merged, jail '%s': %s",
+				idx, jail.name, e,
+				exc_info=logSys.getEffectiveLevel()<=logging.DEBUG)
+		return mi[idx] if mi[idx] is not None else mi['ticket']
+
 	def __checkBan(self):
 		"""Check for IP address to ban.
 
@@ -264,14 +302,11 @@ class Actions(JailThread, Mapping):
 			aInfo["time"] = bTicket.getTime()
 			aInfo["matches"] = "\n".join(bTicket.getMatches())
 			if self._jail.database is not None:
-				aInfo["ipmatches"] = lambda jail=self._jail: "\n".join(
-					jail.database.getBansMerged(ip=ip).getMatches())
-				aInfo["ipjailmatches"] = lambda jail=self._jail: "\n".join(
-					jail.database.getBansMerged(ip=ip, jail=jail).getMatches())
-				aInfo["ipfailures"] = lambda jail=self._jail: \
-					jail.database.getBansMerged(ip=ip).getAttempt()
-				aInfo["ipjailfailures"] = lambda jail=self._jail: \
-					jail.database.getBansMerged(ip=ip, jail=jail).getAttempt()
+				mi4ip = lambda idx, self=self, mi={'ip':ip, 'ticket':bTicket}: self.__getBansMerged(mi, idx)
+				aInfo["ipmatches"]      = lambda: "\n".join(mi4ip('all').getMatches())
+				aInfo["ipjailmatches"]  = lambda: "\n".join(mi4ip('jail').getMatches())
+				aInfo["ipfailures"]     = lambda: mi4ip('all').getAttempt()
+				aInfo["ipjailfailures"] = lambda: mi4ip('jail').getAttempt()
 			if self.__banManager.addBanTicket(bTicket):
 				logSys.notice("[%s] Ban %s" % (self._jail.name, aInfo["ip"]))
 				for name, action in self._actions.iteritems():
diff --git a/fail2ban/server/database.py b/fail2ban/server/database.py
index 351d1829..bbf7adad 100644
--- a/fail2ban/server/database.py
+++ b/fail2ban/server/database.py
@@ -27,7 +27,7 @@ import sqlite3
 import json
 import locale
 from functools import wraps
-from threading import Lock
+from threading import RLock
 
 from .mytime import MyTime
 from .ticket import FailTicket
@@ -123,7 +123,7 @@ class Fail2BanDb(object):
 
 	def __init__(self, filename, purgeAge=24*60*60):
 		try:
-			self._lock = Lock()
+			self._lock = RLock()
 			self._db = sqlite3.connect(
 				filename, check_same_thread=False,
 				detect_types=sqlite3.PARSE_DECLTYPES)
@@ -365,6 +365,10 @@ class Fail2BanDb(object):
 			del self._bansMergedCache[(ticket.getIP(), jail)]
 		except KeyError:
 			pass
+		try:
+			del self._bansMergedCache[(ticket.getIP(), None)]
+		except KeyError:
+			pass
 		#TODO: Implement data parts once arbitrary match keys completed
 		cur.execute(
 			"INSERT INTO bans(jail, ip, timeofban, data) VALUES(?, ?, ?, ?)",
@@ -455,40 +459,41 @@ class Fail2BanDb(object):
 			in a list. When `ip` argument passed, a single `Ticket` is
 			returned.
 		"""
-		cacheKey = None
-		if bantime is None or bantime < 0:
-			cacheKey = (ip, jail)
-			if cacheKey in self._bansMergedCache:
-				return self._bansMergedCache[cacheKey]
-
-		tickets = []
-		ticket = None
-
-		results = list(self._getBans(ip=ip, jail=jail, bantime=bantime))
-		if results:
-			prev_banip = results[0][0]
-			matches = []
-			failures = 0
-			for banip, timeofban, data in results:
-				#TODO: Implement data parts once arbitrary match keys completed
-				if banip != prev_banip:
-					ticket = FailTicket(prev_banip, prev_timeofban, matches)
-					ticket.setAttempt(failures)
-					tickets.append(ticket)
-					# Reset variables
-					prev_banip = banip
-					matches = []
-					failures = 0
-				matches.extend(data['matches'])
-				failures += data['failures']
-				prev_timeofban = timeofban
-			ticket = FailTicket(banip, prev_timeofban, matches)
-			ticket.setAttempt(failures)
-			tickets.append(ticket)
-
-		if cacheKey:
-			self._bansMergedCache[cacheKey] = tickets if ip is None else ticket
-		return tickets if ip is None else ticket
+		with self._lock:
+			cacheKey = None
+			if bantime is None or bantime < 0:
+				cacheKey = (ip, jail)
+				if cacheKey in self._bansMergedCache:
+					return self._bansMergedCache[cacheKey]
+
+			tickets = []
+			ticket = None
+
+			results = list(self._getBans(ip=ip, jail=jail, bantime=bantime))
+			if results:
+				prev_banip = results[0][0]
+				matches = []
+				failures = 0
+				for banip, timeofban, data in results:
+					#TODO: Implement data parts once arbitrary match keys completed
+					if banip != prev_banip:
+						ticket = FailTicket(prev_banip, prev_timeofban, matches)
+						ticket.setAttempt(failures)
+						tickets.append(ticket)
+						# Reset variables
+						prev_banip = banip
+						matches = []
+						failures = 0
+					matches.extend(data['matches'])
+					failures += data['failures']
+					prev_timeofban = timeofban
+				ticket = FailTicket(banip, prev_timeofban, matches)
+				ticket.setAttempt(failures)
+				tickets.append(ticket)
+
+			if cacheKey:
+				self._bansMergedCache[cacheKey] = tickets if ip is None else ticket
+			return tickets if ip is None else ticket
 
 	@commitandrollback
 	def purge(self, cur):