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Editing: filterpoll.py
# 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 # __author__ = "Cyril Jaquier, Yaroslav Halchenko" __copyright__ = "Copyright (c) 2004 Cyril Jaquier; 2012 Yaroslav Halchenko" __license__ = "GPL" import os import time from .filter import FileFilter from .utils import Utils from ..helpers import getLogger, logging # Gets the instance of the logger. logSys = getLogger(__name__) ## # Log reader class. # # This class reads a log file and detects login failures or anything else # that matches a given regular expression. This class is instantiated by # a Jail object. class FilterPoll(FileFilter): ## # Constructor. # # Initialize the filter object with default values. # @param jail the jail object def __init__(self, jail): FileFilter.__init__(self, jail) ## The time of the last modification of the file. self.__prevStats = dict() self.__file404Cnt = dict() logSys.debug("Created FilterPoll") ## # Add a log file path # # @param path log file path def _addLogPath(self, path): self.__prevStats[path] = (0, None, None) # mtime, ino, size self.__file404Cnt[path] = 0 ## # Delete a log path # # @param path the log file to delete def _delLogPath(self, path): del self.__prevStats[path] del self.__file404Cnt[path] ## # Get a modified log path at once # def getModified(self, modlst): for filename in self.getLogPaths(): if self.isModified(filename): modlst.append(filename) return modlst ## # Main loop. # # This function is the main loop of the thread. It checks if the # file has been modified and looks for failures. # @return True when the thread exits nicely def run(self): while self.active: try: if logSys.getEffectiveLevel() <= 4: logSys.log(4, "Woke up idle=%s with %d files monitored", self.idle, self.getLogCount()) if self.idle: if not Utils.wait_for(lambda: not self.active or not self.idle, self.sleeptime * 10, self.sleeptime ): self.ticks += 1 continue # Get file modification modlst = [] Utils.wait_for(lambda: not self.active or self.getModified(modlst), self.sleeptime) if not self.active: # pragma: no cover - timing break for filename in modlst: self.getFailures(filename) self.ticks += 1 if self.ticks % 10 == 0: self.performSvc() except Exception as e: # pragma: no cover if not self.active: # if not active - error by stop... break logSys.error("Caught unhandled exception in main cycle: %r", e, exc_info=logSys.getEffectiveLevel()<=logging.DEBUG) # incr common error counter: self.commonError("unhandled", e) logSys.debug("[%s] filter terminated", self.jailName) return True ## # Checks if the log file has been modified. # # Checks if the log file has been modified using os.stat(). # @return True if log file has been modified def isModified(self, filename): try: logStats = os.stat(filename) stats = logStats.st_mtime, logStats.st_ino, logStats.st_size pstats = self.__prevStats.get(filename, (0,)) if logSys.getEffectiveLevel() <= 4: # we do not want to waste time on strftime etc if not necessary dt = logStats.st_mtime - pstats[0] logSys.log(4, "Checking %s for being modified. Previous/current stats: %s / %s. dt: %s", filename, pstats, stats, dt) # os.system("stat %s | grep Modify" % filename) self.__file404Cnt[filename] = 0 if pstats == stats: return False logSys.debug("%s has been modified", filename) self.__prevStats[filename] = stats return True except Exception as e: # still alive (may be deleted because multi-threaded): if not self.getLog(filename) or self.__prevStats.get(filename) is None: logSys.warning("Log %r seems to be down: %s", filename, e) return False # log error: if self.__file404Cnt[filename] < 2: if e.errno == 2: logSys.debug("Log absence detected (possibly rotation) for %s, reason: %s", filename, e) else: # pragma: no cover logSys.error("Unable to get stat on %s because of: %s", filename, e, exc_info=logSys.getEffectiveLevel()<=logging.DEBUG) # increase file and common error counters: self.__file404Cnt[filename] += 1 self.commonError() if self.__file404Cnt[filename] > 50: logSys.warning("Too many errors. Remove file %r from monitoring process", filename) self.__file404Cnt[filename] = 0 self.delLogPath(filename) return False def getPendingPaths(self): return list(self.__file404Cnt.keys())
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