# 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: 642 $ __author__ = "Cyril Jaquier" __version__ = "$Revision: 642 $" __date__ = "$Date: 2008-01-05 23:33:44 +0100 (Sat, 05 Jan 2008) $" __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 "" with default regular expression for host. regex = regex.replace("", "(?:::f{4,6}:)?(?P[\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