fail2ban/server/regex.py

94 lines
2.5 KiB
Python

# 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: 589 $
__author__ = "Cyril Jaquier"
__version__ = "$Revision: 589 $"
__date__ = "$Date: 2007-06-25 23:43:25 +0200 (Mon, 25 Jun 2007) $"
__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>\S+)")
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