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# 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
# Author: Cyril Jaquier
#
# $Revision$
__author__ = "Cyril Jaquier"
__version__ = "$Revision$"
__date__ = "$Date$"
__copyright__ = "Copyright (c) 2004 Cyril Jaquier"
__license__ = "GPL"
import re, sre_constants
##
# Regular expression class.
#
# This class represents a regular expression with its compiled version.
class Regex:
##
# Constructor.
#
# Creates a new object. This method can throw RegexException in order to
# avoid construction of invalid object.
# @param value the regular expression
def __init__(self, regex):
self._matchCache = None
# Perform shortcuts expansions.
# Replace "<HOST>" with default regular expression for host.
regex = regex.replace("<HOST>", "(?:::f{4,6}:)?(?P<host>[\w\-.^_]+)")
if regex.lstrip() == '':
raise RegexException("Cannot add empty regex")
try:
self._regexObj = re.compile(regex)
self._regex = regex
except sre_constants.error:
raise RegexException("Unable to compile regular expression '%s'" %
regex)
##
# Gets the regular expression.
#
# The effective regular expression used is returned.
# @return the regular expression
def getRegex(self):
return self._regex
##
# Searches the regular expression.
#
# Sets an internal cache (match object) in order to avoid searching for
# the pattern again. This method must be called before calling any other
# method of this object.
# @param value the line
def search(self, value):
self._matchCache = self._regexObj.search(value)
##
# Checks if the previous call to search() matched.
#
# @return True if a match was found, False otherwise
def hasMatched(self):
if self._matchCache:
return True
else:
return False
##
# Exception dedicated to the class Regex.
class RegexException(Exception):
pass
##
# Regular expression class.
#
# This class represents a regular expression with its compiled version.
class FailRegex(Regex):
##
# Constructor.
#
# Creates a new object. This method can throw RegexException in order to
# avoid construction of invalid object.
# @param value the regular expression
def __init__(self, regex):
# Initializes the parent.
Regex.__init__(self, regex)
# Check for group "host"
if "host" not in self._regexObj.groupindex:
raise RegexException("No 'host' group in '%s'" % self._regex)
##
# Returns the matched host.
#
# This corresponds to the pattern matched by the named group "host".
# @return the matched host
def getHost(self):
host = self._matchCache.group("host")
if host == None:
# Gets a few information.
s = self._matchCache.string
r = self._matchCache.re
raise RegexException("No 'host' found in '%s' using '%s'" % (s, r))
return host
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