fail2ban-client

#!/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"
__copyright__ = "Copyright (c) 2004 Cyril Jaquier"
__license__ = "GPL"

import sys, string, os, pickle, re, logging, signal
import getopt, time, shlex, socket

# Inserts our own modules path first in the list
# fix for bug #343821
try:
	from common.version import version
except ImportError, e:
	sys.path.insert(1, "/usr/share/fail2ban")
	from common.version import version

# Now we can import the rest of modules
from common.protocol import printFormatted
from client.csocket import CSocket
from client.configurator import Configurator
from client.beautifier import Beautifier

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

##
#
# @todo This class needs cleanup.

class Fail2banClient:

	SERVER = "fail2ban-server"
	PROMPT = "fail2ban> "

	def __init__(self):
		self.__argv = None
		self.__stream = None
		self.__configurator = Configurator()
		self.__conf = dict()
		self.__conf["conf"] = "/etc/fail2ban"
		self.__conf["dump"] = False
		self.__conf["force"] = False
		self.__conf["verbose"] = 1
		self.__conf["interactive"] = False
		self.__conf["socket"] = None
		self.__conf["pidfile"] = None

	def dispVersion(self):
		print "Fail2Ban v" + version
		print
		print "Copyright (c) 2004-2008 Cyril Jaquier, 2008- Fail2Ban Contributors"
		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>."

	def dispUsage(self):
		""" Prints Fail2Ban command line options and exits
		"""
		print "Usage: "+self.__argv[0]+" [OPTIONS] <COMMAND>"
		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 "Options:"
		print "    -c <DIR>                configuration directory"
		print "    -s <FILE>               socket path"
		print "    -p <FILE>               pidfile path"
		print "    -d                      dump configuration. For debugging"
		print "    -i                      interactive mode"
		print "    -v                      increase verbosity"
		print "    -q                      decrease verbosity"
		print "    -x                      force execution of the server (remove socket file)"
		print "    -h, --help              display this help message"
		print "    -V, --version           print the version"
		print
		print "Command:"

		# Prints the protocol
		printFormatted()

		print
		print "Report bugs to https://github.com/fail2ban/fail2ban/issues"

	def dispInteractive(self):
		print "Fail2Ban v" + version + " reads log file that contains password failure report"
		print "and bans the corresponding IP addresses using firewall rules."
		print

	def __sigTERMhandler(self, signum, frame):
		# Print a new line because we probably come from wait
		print
		logSys.warn("Caught signal %d. Exiting" % signum)
		sys.exit(-1)

	def __getCmdLineOptions(self, optList):
		""" Gets the command line options
		"""
		for opt in optList:
			if opt[0] == "-c":
				self.__conf["conf"] = opt[1]
			elif opt[0] == "-s":
				self.__conf["socket"] = opt[1]
			elif opt[0] == "-p":
				self.__conf["pidfile"] = opt[1]
			elif opt[0] == "-d":
				self.__conf["dump"] = True
			elif opt[0] == "-v":
				self.__conf["verbose"] = self.__conf["verbose"] + 1
			elif opt[0] == "-q":
				self.__conf["verbose"] = self.__conf["verbose"] - 1
			elif opt[0] == "-x":
				self.__conf["force"] = True
			elif opt[0] == "-i":
				self.__conf["interactive"] = True
			elif opt[0] in ["-h", "--help"]:
				self.dispUsage()
				sys.exit(0)
			elif opt[0] in ["-V", "--version"]:
				self.dispVersion()
				sys.exit(0)

	def __ping(self):
		return self.__processCmd([["ping"]], False)

	def __processCmd(self, cmd, showRet = True):
		beautifier = Beautifier()
		for c in cmd:
			beautifier.setInputCmd(c)
			try:
				client = CSocket(self.__conf["socket"])
				ret = client.send(c)
				if ret[0] == 0:
					logSys.debug("OK : " + `ret[1]`)
					if showRet:
						print beautifier.beautify(ret[1])
				else:
					logSys.error("NOK: " + `ret[1].args`)
					if showRet:
						print beautifier.beautifyError(ret[1])
					return False
			except socket.error:
				if showRet:
					logSys.error("Unable to contact server. Is it running?")
				return False
			except Exception, e:
				if showRet:
					logSys.error(e)
				return False
		return True

	##
	# Process a command line.
	#
	# Process one command line and exit.
	# @param cmd the command line

	def __processCommand(self, cmd):
		if len(cmd) == 1 and cmd[0] == "start":
			if self.__ping():
				logSys.error("Server already running")
				return False
			else:
				# Read the config
				ret = self.__readConfig()
				# Do not continue if configuration is not 100% valid
				if not ret:
					return False
				# verify that directory for the socket file exists
				socket_dir = os.path.dirname(self.__conf["socket"])
				if not os.path.exists(socket_dir):
					logSys.error(
						"There is no directory %s to contain the socket file %s."
						% (socket_dir, self.__conf["socket"]))
					return False
				if not os.access(socket_dir, os.W_OK | os.X_OK):
					logSys.error(
						"Directory %s exists but not accessible for writing"
						% (socket_dir,))
					return False
				# Start the server
				self.__startServerAsync(self.__conf["socket"],
										self.__conf["pidfile"],
										self.__conf["force"])
				try:
					# Wait for the server to start
					self.__waitOnServer()
					# Configure the server
					self.__processCmd(self.__stream, False)
					return True
				except ServerExecutionException:
					logSys.error("Could not start server. Maybe an old "
								 "socket file is still present. Try to "
								 "remove " + self.__conf["socket"] + ". If "
								 "you used fail2ban-client to start the "
								 "server, adding the -x option will do it")
					return False
		elif len(cmd) == 1 and cmd[0] == "reload":
			if self.__ping():
				ret = self.__readConfig()
				# Do not continue if configuration is not 100% valid
				if not ret:
					return False
				self.__processCmd([['stop', 'all']], False)
				# Configure the server
				return self.__processCmd(self.__stream, False)
			else:
				logSys.error("Could not find server")
				return False
		elif len(cmd) == 2 and cmd[0] == "reload":
			if self.__ping():
				jail = cmd[1]
				ret = self.__readConfig(jail)
				# Do not continue if configuration is not 100% valid
				if not ret:
					return False
				self.__processCmd([['stop', jail]], False)
				# Configure the server
				return self.__processCmd(self.__stream, False)
			else:
				logSys.error("Could not find server")
				return False
		else:
			return self.__processCmd([cmd])


	##
	# Start Fail2Ban server.
	#
	# Start the Fail2ban server in daemon mode.

	def __startServerAsync(self, socket, pidfile, force = False):
		# Forks the current process.
		pid = os.fork()
		if pid == 0:
			args = list()
			args.append(self.SERVER)
			# Start in background mode.
			args.append("-b")
			# Set the socket path.
			args.append("-s")
			args.append(socket)
			# Set the pidfile
			args.append("-p")
			args.append(pidfile)
			# Force the execution if needed.
			if force:
				args.append("-x")
			try:
				# Use the current directory.
				exe = os.path.abspath(os.path.join(sys.path[0], self.SERVER))
				logSys.debug("Starting %r with args %r" % (exe, args))
				os.execv(exe, args)
			except OSError:
				try:
					# Use the PATH env.
					logSys.warning("Initial start attempt failed.  Starting %r with the same args" % (self.SERVER,))
					os.execvp(self.SERVER, args)
				except OSError:
					logSys.error("Could not start %s" % self.SERVER)
					os.exit(-1)

	def __waitOnServer(self):
		# Wait for the server to start
		cnt = 0
		if self.__conf["verbose"] > 1:
			pos = 0
			delta = 1
			mask = "[          ]"
		while not self.__ping():
			# Wonderful visual :)
			if self.__conf["verbose"] > 1:
				pos += delta
				sys.stdout.write("\rINFO   " + mask[:pos] + '#' + mask[pos+1:] +
								 " Waiting on the server...")
				sys.stdout.flush()
				if pos > len(mask)-3:
					delta = -1
				elif pos < 2:
					delta = 1
			# The server has 30 seconds to start.
			if cnt >= 300:
				if self.__conf["verbose"] > 1:
					sys.stdout.write('\n')
				raise ServerExecutionException("Failed to start server")
			time.sleep(0.1)
			cnt += 1
		if self.__conf["verbose"] > 1:
			sys.stdout.write('\n')


	def start(self, argv):
		# Command line options
		self.__argv = argv

		# Install signal handlers
		signal.signal(signal.SIGTERM, self.__sigTERMhandler)
		signal.signal(signal.SIGINT, self.__sigTERMhandler)

		# Reads the command line options.
		try:
			cmdOpts = 'hc:s:p:xdviqV'
			cmdLongOpts = ['help', 'version']
			optList, args = getopt.getopt(self.__argv[1:], cmdOpts, cmdLongOpts)
		except getopt.GetoptError:
			self.dispUsage()
			return False

		self.__getCmdLineOptions(optList)

		verbose = self.__conf["verbose"]
		if verbose <= 0:
			logSys.setLevel(logging.ERROR)
		elif verbose == 1:
			logSys.setLevel(logging.WARN)
		elif verbose == 2:
			logSys.setLevel(logging.INFO)
		else:
			logSys.setLevel(logging.DEBUG)
		# Add the default logging handler to dump to stderr
		logout = logging.StreamHandler(sys.stderr)
		# set a format which is simpler for console use
		formatter = logging.Formatter('%(levelname)-6s %(message)s')
		# tell the handler to use this format
		logout.setFormatter(formatter)
		logSys.addHandler(logout)

		# Set the configuration path
		self.__configurator.setBaseDir(self.__conf["conf"])

		# Set socket path
		self.__configurator.readEarly()
		conf = self.__configurator.getEarlyOptions()
		if self.__conf["socket"] is None:
			self.__conf["socket"] = conf["socket"]
		if self.__conf["pidfile"] is None:
			self.__conf["pidfile"] = conf["pidfile"]
		logSys.info("Using socket file " + self.__conf["socket"])

		if self.__conf["dump"]:
			ret = self.__readConfig()
			self.dumpConfig(self.__stream)
			return ret

		# Interactive mode
		if self.__conf["interactive"]:
			try:
				import readline
			except ImportError:
				logSys.error("Readline not available")
				return False
			try:
				ret = True
				if len(args) > 0:
					ret = self.__processCommand(args)
				if ret:
					readline.parse_and_bind("tab: complete")
					self.dispInteractive()
					while True:
						cmd = raw_input(self.PROMPT)
						if cmd == "exit" or cmd == "quit":
							# Exit
							return True
						if cmd == "help":
							self.dispUsage()
						elif not cmd == "":
							try:
								self.__processCommand(shlex.split(cmd))
							except Exception, e:
								logSys.error(e)
			except (EOFError, KeyboardInterrupt):
				print
				return True
		# Single command mode
		else:
			if len(args) < 1:
				self.dispUsage()
				return False
			return self.__processCommand(args)

	def __readConfig(self, jail=None):
		# Read the configuration
		# TODO: get away from stew of return codes and exception
		# handling -- handle via exceptions
		try:
			self.__configurator.readAll()
			ret = self.__configurator.getOptions(jail)
			self.__configurator.convertToProtocol()
			self.__stream = self.__configurator.getConfigStream()
		except Exception, e:
			logSys.error("Failed during configuration: %s" % e)
			ret = False
		return ret

	#@staticmethod
	def dumpConfig(cmd):
		for c in cmd:
			print c
		return True
	dumpConfig = staticmethod(dumpConfig)


class ServerExecutionException(Exception):
	pass

if __name__ == "__main__": # pragma: no cover - can't test main
	client = Fail2banClient()
	# Exit with correct return value
	if client.start(sys.argv):
		sys.exit(0)
	else:
		sys.exit(-1)