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

# Inserts our own modules path first in the list
# fix for bug #343821
if os.path.abspath(__file__).startswith('/usr/'):
	# makes sense to use system-wide library iff -regex is also under /usr/
    sys.path.insert(1, "/usr/share/fail2ban")

from client.configparserinc import SafeConfigParserWithIncludes
from ConfigParser import NoOptionError, NoSectionError, MissingSectionHeaderError
from common.version import version
from server.filter import Filter
from 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.__verbose = False
		# 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 "    -h, --help              display this help message"
		print "    -V, --version           print the version"
		print "    -v, --verbose           verbose output"
		print
		print "Log:"
		print "    string                  a string representing a log line"
		print "    filename                path to a log file (/var/log/auth.log)"
		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 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

	#@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
		else:
			if len(value) > 53:
				stripReg = value[0:50] + "..."
			else:
				stripReg = value
			print "Use regex line : " + stripReg
			self.__failregex = [RegexStat(value)]
		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

			
if __name__ == "__main__":
	fail2banRegex = Fail2banRegex()
	# Reads the command line options.
	try:
		cmdOpts = 'hVcv'
		cmdLongOpts = ['help', 'version', 'verbose']
		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)
				print "Use log file   : " + cmd_log
				print
				for line in hdlr:
					fail2banRegex.testIgnoreRegex(line)
					fail2banRegex.testRegex(line)
			except IOError, e:
				print e
				print
				sys.exit(-1)
		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)