fail2ban/bin/fail2ban-regex

#!/usr/bin/python
# 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.

__author__ = "Cyril Jaquier, Yaroslav Halchenko"
__copyright__ = "Copyright (c) 2004 Cyril Jaquier, 2012 Yaroslav Halchenko"
__license__ = "GPL"

import getopt, sys, time, logging, os, locale
from ConfigParser import NoOptionError, NoSectionError, MissingSectionHeaderError

try:
	from fail2ban.server.filtersystemd import FilterSystemd
	from systemd import journal
except:
	journal = None

from fail2ban.version import version
from fail2ban.client.configparserinc import SafeConfigParserWithIncludes
from fail2ban.server.filter import Filter
from fail2ban.server.failregex import RegexException

# Gets the instance of the logger.
logSys = logging.getLogger("fail2ban.regex")

class RegexStat:

	def __init__(self, failregex):
		self.__stats = 0
		self.__failregex = failregex
		self.__ipList = list()

	def __str__(self):
		return "%s(%r) %d failed: %s" \
		  % (self.__class__, self.__failregex, self.__stats, self.__ipList)

	def inc(self):
		self.__stats += 1

	def getStats(self):
		return self.__stats

	def getFailRegex(self):
		return self.__failregex

	def appendIP(self, value):
		self.__ipList.extend(value)

	def getIPList(self):
		return self.__ipList

class Fail2banRegex:

	test = None

	CONFIG_DEFAULTS = {'configpath' : "/etc/fail2ban/"}

	def __init__(self):
		self.__filter = Filter(None)
		self.__ignoreregex = list()
		self.__failregex = list()
		self.__journalmatch = ""
		self.__verbose = False
		self.__maxlines_set = False		  # so we allow to override maxlines in cmdline
		self.encoding = locale.getpreferredencoding()
		# Setup logging
		logging.getLogger("fail2ban").handlers = []
		self.__hdlr = logging.StreamHandler(Fail2banRegex.test)
		# set a format which is simpler for console use
		formatter = logging.Formatter("%(message)s")
		# tell the handler to use this format
		self.__hdlr.setFormatter(formatter)
		self.__logging_level = self.__verbose and logging.DEBUG or logging.WARN
		logging.getLogger("fail2ban").addHandler(self.__hdlr)
		logging.getLogger("fail2ban").setLevel(logging.ERROR)

	#@staticmethod
	def dispVersion():
		print "Fail2Ban v" + version
		print
		print "Copyright (c) 2004-2008 Cyril Jaquier"
		print "Copyright of modifications held by their respective authors."
		print "Licensed under the GNU General Public License v2 (GPL)."
		print
		print "Written by Cyril Jaquier <cyril.jaquier@fail2ban.org>."
		print "Many contributions by Yaroslav O. Halchenko <debian@onerussian.com>."
	dispVersion = staticmethod(dispVersion)

	#@staticmethod
	def dispUsage():
		print "Usage: "+sys.argv[0]+" [OPTIONS] <LOG> <REGEX> [IGNOREREGEX]"
		print
		print "Fail2Ban v" + version + " reads log file that contains password failure report"
		print "and bans the corresponding IP addresses using firewall rules."
		print
		print "This tools can test regular expressions for \"fail2ban\"."
		print
		print "Options:"
		print "    -e ENCODING, --encoding=ENCODING"
		print "                            set the file encoding. default:system locale"
		print "    -h, --help              display this help message"
		print "    -V, --version           print the version"
		print "    -v, --verbose           verbose output"
		print "    -l INT, --maxlines=INT  set maxlines for multi-line regex default: 1"
		print "    -m MATCHES, --matches=MATCHES"
		print "                            journalctl style matches, overriding filter file."
		print "                            Special value \"ALL\" searches entire journal"
		print
		print "Log:"
		print "    string                  a string representing a log line"
		print "    filename                path to a log file (/var/log/auth.log)"
		print "    \"systemd-journal\"       search systemd journal (systemd python required)"
		print
		print "Regex:"
		print "    string                  a string representing a 'failregex'"
		print "    filename                path to a filter file (filter.d/sshd.conf)"
		print
		print "IgnoreRegex:"
		print "    string                  a string representing an 'ignoreregex'"
		print "    filename                path to a filter file (filter.d/sshd.conf)"
		print
		print "Report bugs to https://github.com/fail2ban/fail2ban/issues"
	dispUsage = staticmethod(dispUsage)

	def setMaxLines(self, v):
		if not self.__maxlines_set:
			self.__filter.setMaxLines(int(v))
			self.__maxlines_set = True

	def getCmdLineOptions(self, optList):
		""" Gets the command line options
		"""
		for opt in optList:
			if opt[0] in ["-h", "--help"]:
				self.dispUsage()
				sys.exit(0)
			elif opt[0] in ["-V", "--version"]:
				self.dispVersion()
				sys.exit(0)
			elif opt[0] in ["-v", "--verbose"]:
				self.__verbose = True
			elif opt[0] in ["-e", "--encoding"]:
				self.encoding = opt[1]
			elif opt[0] in ["-l", "--maxlines"]:
				try:
					self.setMaxLines(opt[1])
				except ValueError:
					print "Invlaid value for maxlines: %s" % (
                        opt[1])
					fail2banRegex.dispUsage()
					sys.exit(-1)

	#@staticmethod
	def logIsFile(value):
		return os.path.isfile(value)
	logIsFile = staticmethod(logIsFile)

	def readIgnoreRegex(self, value):
		if os.path.isfile(value):
			reader = SafeConfigParserWithIncludes(defaults=self.CONFIG_DEFAULTS)
			try:
				reader.read(value)
				print "Use ignoreregex file : " + value
				self.__ignoreregex = [RegexStat(m)
									for m in reader.get("Definition", "ignoreregex").split('\n')]
			except NoSectionError:
				print "No [Definition] section in " + value
				print
				return False
			except NoOptionError:
				print "No failregex option in " + value
				print
				return False
			except MissingSectionHeaderError:
				print "No section headers in " + value
				print
				return False
		else:
			if len(value) > 53:
				stripReg = value[0:50] + "..."
			else:
				stripReg = value
			print "Use ignoreregex line : " + stripReg
			self.__ignoreregex = [RegexStat(value)]
		return True

	def readRegex(self, value):
		if os.path.isfile(value):
			reader = SafeConfigParserWithIncludes(defaults=self.CONFIG_DEFAULTS)
			try:
				reader.read(value)
				print "Use regex file : " + value
				self.__failregex = [RegexStat(m)
									for m in reader.get("Definition", "failregex").split('\n')]
			except NoSectionError:
				print "No [Definition] section in " + value
				print
				return False
			except NoOptionError:
				print "No failregex option in " + value
				print
				return False
			except MissingSectionHeaderError:
				print "No section headers in " + value
				print
				return False

			# Read out and set possible value of maxlines
			try:
				maxlines = reader.get("Init", "maxlines")
			except NoSectionError, NoOptionError:
				# No [Init].maxlines found.
				pass
			else:
				try:
					self.setMaxLines(maxlines)
				except ValueError:
					print "ERROR: Invalid value for maxlines (%(maxlines)r) " \
					      "read from %(value)s" % locals()
					return False
			try:
				self.__journalmatch = reader.get("Init", "journalmatch")
			except (NoSectionError, NoOptionError):
				pass
		else:
			if len(value) > 53:
				stripReg = value[0:50] + "..."
			else:
				stripReg = value
			print "Use regex line : " + stripReg
			self.__failregex = [RegexStat(value)]

		print "Use maxlines   : %d" % self.__filter.getMaxLines()
		return True

	def testIgnoreRegex(self, line):
		found = False
		for regex in self.__ignoreregex:
			logging.getLogger("fail2ban").setLevel(self.__logging_level)
			try:
				self.__filter.addIgnoreRegex(regex.getFailRegex())
				try:
					ret = self.__filter.ignoreLine(line)
					if ret:
						regex.inc()
				except RegexException, e:
					print e
					return False
			finally:
				self.__filter.delIgnoreRegex(0)
				logging.getLogger("fail2ban").setLevel(self.__logging_level)

	def testRegex(self, line):
		found = False
		for regex in self.__ignoreregex:
			self.__filter.addIgnoreRegex(regex.getFailRegex())
		for regex in self.__failregex:
			logging.getLogger("fail2ban").setLevel(logging.DEBUG)
			try:
				self.__filter.addFailRegex(regex.getFailRegex())
				try:
					ret = self.__filter.processLine(line)
					if not len(ret) == 0:
						if found == True:
							ret[0].append(True)
						else:
							found = True
							ret[0].append(False)
						regex.inc()
						regex.appendIP(ret)
				except RegexException, e:
					print e
					return False
				except IndexError:
					print "Sorry, but no <host> found in regex"
					return False
			finally:
				self.__filter.delFailRegex(0)
				logging.getLogger("fail2ban").setLevel(logging.CRITICAL)
		for regex in self.__ignoreregex:
					self.__filter.delIgnoreRegex(0)

	def printStats(self):
		print
		print "Results"
		print "======="
		print

		def print_failregexes(title, failregexes):
			# Print title
			total, out = 0, []
			for cnt, failregex in enumerate(failregexes):
				match = failregex.getStats()
				total += match
				if (match or self.__verbose):
					out.append("|  %d) [%d] %s" % (cnt+1, match, failregex.getFailRegex()))
			print "%s: %d total" % (title, total)
			if len(out):
				print "|- #) [# of hits] regular expression"
				print '\n'.join(out)
				print '`-'
			print
			return total

		# Print title
		total = print_failregexes("Failregex", self.__failregex)
		_ = print_failregexes("Ignoreregex", self.__ignoreregex)

		print "Summary"
		print "======="
		print

		if total == 0:
			print "Sorry, no match"
			print
			print "Look at the above section 'Running tests' which could contain important"
			print "information."
			return False
		else:
			# Print stats
			print "Addresses found:"
			for cnt, failregex in enumerate(self.__failregex):
				if self.__verbose or len(failregex.getIPList()):
					print "[%d]" % (cnt+1)
					for ip in failregex.getIPList():
						timeTuple = time.localtime(ip[1])
						timeString = time.strftime("%a %b %d %H:%M:%S %Y", timeTuple)
						print "    %s (%s)%s" % (
							ip[0], timeString, ip[2] and " (already matched)" or "")
			print

			print "Date template hits:"
			for template in self.__filter.dateDetector.getTemplates():
				if self.__verbose or template.getHits():
					print `template.getHits()` + " hit(s): " + template.getName()
			print

			print "Success, the total number of match is " + str(total)
			print
			print "However, look at the above section 'Running tests' which could contain important"
			print "information."
			return True

	def getJournalMatch(self):
		return self.__journalmatch

if __name__ == "__main__":
	fail2banRegex = Fail2banRegex()
	# Reads the command line options.
	try:
		cmdOpts = 'hVcvl:e:m:'
		cmdLongOpts = ['help', 'version', 'verbose', 'maxlines=', 'encoding=',
			'matches=']
		optList, args = getopt.getopt(sys.argv[1:], cmdOpts, cmdLongOpts)
	except getopt.GetoptError:
		fail2banRegex.dispUsage()
		sys.exit(-1)
	# Process command line
	fail2banRegex.getCmdLineOptions(optList)

	# We need 2 or 3 parameters
	if not len(args) in (2, 3):
		fail2banRegex.dispUsage()
		sys.exit(-1)
	else:
		print
		print "Running tests"
		print "============="
		print

		cmd_log, cmd_regex = args[:2]

		if len(args) == 3:
			fail2banRegex.readIgnoreRegex(args[2]) or sys.exit(-1)

		fail2banRegex.readRegex(cmd_regex) or sys.exit(-1)

		if fail2banRegex.logIsFile(cmd_log):
			try:
				hdlr = open(cmd_log, 'rb')
				print "Use log file   : " + cmd_log
				print "Use encoding   : " + fail2banRegex.encoding
				print
				for line in hdlr:
					try:
						line = line.decode(fail2banRegex.encoding, 'strict')
					except UnicodeDecodeError:
						if sys.version_info >= (3,): # Python 3 must be decoded
							line = line.decode(fail2banRegex.encoding, 'ignore')
					fail2banRegex.testIgnoreRegex(line)
					fail2banRegex.testRegex(line)
			except IOError, e:
				print e
				print
				sys.exit(-1)
		elif cmd_log == "systemd-journal":
			if journal is None:
				print "Error: systemd library not found. Exiting..."
				sys.exit(-1)
			myjournal = journal.Reader()
			journalmatch = ""
			# Parse journal matches from command line
			for opt in optList:
				if opt[0] in ["-m", "--matches"]:
					journalmatch = opt[1]
			# If no command line option, take journal match from filter
			if not journalmatch:
				journalmatch = fail2banRegex.getJournalMatch()
			try:
				if journalmatch != "ALL":
					for element in journalmatch.split():
						if element == "+":
							myjournal.add_disjunction()
						else:
							myjournal.add_match(element)
			except ValueError:
				print "Error: Invalid journal match: %s" % journalmatch
				print "Exiting..."
				sys.exit(-1)
			print "Use systemd journal match: %s" % (journalmatch or "ALL")
			while True:
				try:
					entry = myjournal.get_next()
				except OSError:
					continue
				else:
					if not entry:
						break
				line = FilterSystemd.formatJournalEntry(entry)
				fail2banRegex.testIgnoreRegex(line)
				fail2banRegex.testRegex(line)
		else:
			if len(sys.argv[1]) > 53:
				stripLog = cmd_log[0:50] + "..."
			else:
				stripLog = cmd_log
			print "Use single line: " + stripLog
			print
			fail2banRegex.testIgnoreRegex(cmd_log)
			fail2banRegex.testRegex(cmd_log)

		fail2banRegex.printStats() or sys.exit(-1)