mirror of https://github.com/fail2ban/fail2ban
608 lines
15 KiB
Python
608 lines
15 KiB
Python
# emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: t -*-
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# vi: set ft=python sts=4 ts=4 sw=4 noet :
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# This file is part of Fail2Ban.
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#
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# Fail2Ban is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# Fail2Ban is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with Fail2Ban; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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# Author: Cyril Jaquier
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#
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# $Revision$
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__author__ = "Cyril Jaquier"
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__version__ = "$Revision$"
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__date__ = "$Date$"
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__copyright__ = "Copyright (c) 2004 Cyril Jaquier"
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__license__ = "GPL"
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from failmanager import FailManager
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from ticket import FailTicket
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from jailthread import JailThread
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from datedetector import DateDetector
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from mytime import MyTime
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from failregex import FailRegex, Regex, RegexException
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import logging, re, os, fcntl, time
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# Gets the instance of the logger.
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logSys = logging.getLogger("fail2ban.filter")
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##
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# Log reader class.
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#
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# This class reads a log file and detects login failures or anything else
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# that matches a given regular expression. This class is instanciated by
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# a Jail object.
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class Filter(JailThread):
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##
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# Constructor.
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#
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# Initialize the filter object with default values.
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# @param jail the jail object
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def __init__(self, jail):
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JailThread.__init__(self)
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## The jail which contains this filter.
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self.jail = jail
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## The failures manager.
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self.failManager = FailManager()
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## The regular expression list matching the failures.
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self.__failRegex = list()
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## The regular expression list with expressions to ignore.
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self.__ignoreRegex = list()
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## The amount of time to look back.
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self.__findTime = 6000
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## The ignore IP list.
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self.__ignoreIpList = []
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self.dateDetector = DateDetector()
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self.dateDetector.addDefaultTemplate()
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logSys.debug("Created Filter")
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##
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# Add a regular expression which matches the failure.
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#
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# The regular expression can also match any other pattern than failures
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# and thus can be used for many purporse.
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# @param value the regular expression
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def addFailRegex(self, value):
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try:
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regex = FailRegex(value)
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self.__failRegex.append(regex)
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except RegexException, e:
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logSys.error(e)
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def delFailRegex(self, index):
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try:
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del self.__failRegex[index]
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except IndexError:
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logSys.error("Cannot remove regular expression. Index %d is not "
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"valid" % index)
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##
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# Get the regular expression which matches the failure.
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#
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# @return the regular expression
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def getFailRegex(self):
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failRegex = list()
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for regex in self.__failRegex:
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failRegex.append(regex.getRegex())
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return failRegex
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##
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# Add the regular expression which matches the failure.
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#
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# The regular expression can also match any other pattern than failures
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# and thus can be used for many purporse.
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# @param value the regular expression
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def addIgnoreRegex(self, value):
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try:
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regex = Regex(value)
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self.__ignoreRegex.append(regex)
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except RegexException, e:
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logSys.error(e)
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def delIgnoreRegex(self, index):
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try:
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del self.__ignoreRegex[index]
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except IndexError:
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logSys.error("Cannot remove regular expression. Index %d is not "
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"valid" % index)
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##
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# Get the regular expression which matches the failure.
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#
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# @return the regular expression
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def getIgnoreRegex(self):
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ignoreRegex = list()
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for regex in self.__ignoreRegex:
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ignoreRegex.append(regex.getRegex())
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return ignoreRegex
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##
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# Set the time needed to find a failure.
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#
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# This value tells the filter how long it has to take failures into
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# account.
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# @param value the time
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def setFindTime(self, value):
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self.__findTime = value
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self.failManager.setMaxTime(value)
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logSys.info("Set findtime = %s" % value)
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##
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# Get the time needed to find a failure.
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#
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# @return the time
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def getFindTime(self):
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return self.__findTime
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##
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# Set the maximum retry value.
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#
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# @param value the retry value
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def setMaxRetry(self, value):
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self.failManager.setMaxRetry(value)
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logSys.info("Set maxRetry = %s" % value)
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##
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# Get the maximum retry value.
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#
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# @return the retry value
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def getMaxRetry(self):
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return self.failManager.getMaxRetry()
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##
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# Main loop.
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#
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# This function is the main loop of the thread. It checks if the
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# file has been modified and looks for failures.
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# @return True when the thread exits nicely
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def run(self):
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raise Exception("run() is abstract")
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##
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# Ban an IP - http://blogs.buanzo.com.ar/2009/04/fail2ban-patch-ban-ip-address-manually.html
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# Arturo 'Buanzo' Busleiman <buanzo@buanzo.com.ar>
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#
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# to enable banip fail2ban-client BAN command
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def addBannedIP(self, ip):
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unixTime = time.time()
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self.failManager.addFailure(FailTicket(ip, unixTime))
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return ip
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##
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# Add an IP/DNS to the ignore list.
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#
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# IP addresses in the ignore list are not taken into account
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# when finding failures. CIDR mask and DNS are also accepted.
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# @param ip IP address to ignore
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def addIgnoreIP(self, ip):
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logSys.debug("Add " + ip + " to ignore list")
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self.__ignoreIpList.append(ip)
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def delIgnoreIP(self, ip):
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logSys.debug("Remove " + ip + " from ignore list")
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self.__ignoreIpList.remove(ip)
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def getIgnoreIP(self):
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return self.__ignoreIpList
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##
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# Check if IP address/DNS is in the ignore list.
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#
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# Check if the given IP address matches an IP address/DNS or a CIDR
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# mask in the ignore list.
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# @param ip IP address
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# @return True if IP address is in ignore list
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def inIgnoreIPList(self, ip):
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for i in self.__ignoreIpList:
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# An empty string is always false
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if i == "":
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continue
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s = i.split('/', 1)
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# IP address without CIDR mask
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if len(s) == 1:
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s.insert(1, '32')
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s[1] = long(s[1])
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try:
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a = DNSUtils.cidr(s[0], s[1])
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b = DNSUtils.cidr(ip, s[1])
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except Exception:
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# Check if IP in DNS
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ips = DNSUtils.dnsToIp(i)
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if ip in ips:
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return True
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else:
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continue
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if a == b:
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return True
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return False
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def processLine(self, line):
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try:
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# Decode line to UTF-8
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l = line.decode('utf-8')
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except UnicodeDecodeError:
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l = line
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timeMatch = self.dateDetector.matchTime(l)
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if timeMatch:
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# Lets split into time part and log part of the line
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timeLine = timeMatch.group()
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# Lets leave the beginning in as well, so if there is no
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# anchore at the beginning of the time regexp, we don't
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# at least allow injection. Should be harmless otherwise
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logLine = l[:timeMatch.start()] + l[timeMatch.end():]
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else:
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timeLine = l
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logLine = l
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return self.findFailure(timeLine, logLine)
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def processLineAndAdd(self, line):
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for element in self.processLine(line):
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ip = element[0]
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unixTime = element[1]
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logSys.debug("Processing line with time:%s and ip:%s"
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% (unixTime, ip))
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if unixTime < MyTime.time() - self.getFindTime():
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logSys.debug("Ignore line since time %s < %s - %s"
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% (unixTime, MyTime.time(), self.getFindTime()))
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break
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if self.inIgnoreIPList(ip):
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logSys.debug("Ignore %s" % ip)
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continue
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logSys.debug("Found %s" % ip)
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self.failManager.addFailure(FailTicket(ip, unixTime, [line]))
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##
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# Returns true if the line should be ignored.
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#
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# Uses ignoreregex.
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# @param line: the line
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# @return: a boolean
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def ignoreLine(self, line):
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for ignoreRegex in self.__ignoreRegex:
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ignoreRegex.search(line)
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if ignoreRegex.hasMatched():
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return True
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return False
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##
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# Finds the failure in a line given split into time and log parts.
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#
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# Uses the failregex pattern to find it and timeregex in order
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# to find the logging time.
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# @return a dict with IP and timestamp.
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def findFailure(self, timeLine, logLine):
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failList = list()
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# Checks if we must ignore this line.
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if self.ignoreLine(logLine):
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# The ignoreregex matched. Return.
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return failList
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# Iterates over all the regular expressions.
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for failRegex in self.__failRegex:
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failRegex.search(logLine)
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if failRegex.hasMatched():
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# The failregex matched.
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date = self.dateDetector.getUnixTime(timeLine)
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if date == None:
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logSys.debug("Found a match for '" + logLine +"' but no "
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+ "valid date/time found for '"
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+ timeLine + "'. Please contact the "
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+ "author in order to get support for this "
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+ "format")
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else:
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try:
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host = failRegex.getHost()
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ipMatch = DNSUtils.textToIp(host)
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if ipMatch:
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for ip in ipMatch:
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failList.append([ip, date])
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# We matched a regex, it is enough to stop.
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break
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except RegexException, e:
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logSys.error(e)
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return failList
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##
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# Get the status of the filter.
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#
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# Get some informations about the filter state such as the total
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# number of failures.
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# @return a list with tuple
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def status(self):
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ret = [("Currently failed", self.failManager.size()),
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("Total failed", self.failManager.getFailTotal())]
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return ret
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class FileFilter(Filter):
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def __init__(self, jail):
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Filter.__init__(self, jail)
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## The log file path.
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self.__logPath = []
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##
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# Add a log file path
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#
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# @param path log file path
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def addLogPath(self, path, tail = False):
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container = FileContainer(path, tail)
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self.__logPath.append(container)
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##
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# Delete a log path
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#
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# @param path the log file to delete
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def delLogPath(self, path):
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for log in self.__logPath:
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if log.getFileName() == path:
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self.__logPath.remove(log)
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return
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##
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# Get the log file path
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#
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# @return log file path
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def getLogPath(self):
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return self.__logPath
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##
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# Check whether path is already monitored.
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#
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# @param path The path
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# @return True if the path is already monitored else False
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def containsLogPath(self, path):
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for log in self.__logPath:
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if log.getFileName() == path:
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return True
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return False
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def getFileContainer(self, path):
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for log in self.__logPath:
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if log.getFileName() == path:
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return log
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return None
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##
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# Gets all the failure in the log file.
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#
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# Gets all the failure in the log file which are newer than
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# MyTime.time()-self.findTime. When a failure is detected, a FailTicket
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# is created and is added to the FailManager.
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def getFailures(self, filename):
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container = self.getFileContainer(filename)
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if container == None:
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logSys.error("Unable to get failures in " + filename)
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return False
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# Try to open log file.
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try:
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container.open()
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except Exception, e:
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logSys.error("Unable to open %s" % filename)
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logSys.exception(e)
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return False
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line = container.readline()
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while not line == "":
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if not self._isActive():
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# The jail has been stopped
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break
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self.processLineAndAdd(line)
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# Read a new line.
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line = container.readline()
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container.close()
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return True
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def status(self):
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ret = Filter.status(self)
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path = [m.getFileName() for m in self.getLogPath()]
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ret.append(("File list", path))
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return ret
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##
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# FileContainer class.
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#
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# This class manages a file handler and takes care of log rotation detection.
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# In order to detect log rotation, the hash (MD5) of the first line of the file
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# is computed and compared to the previous hash of this line.
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try:
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import hashlib
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md5sum = hashlib.md5
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except ImportError:
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# hashlib was introduced in Python 2.5. For compatibility with those
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# elderly Pythons, import from md5
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import md5
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md5sum = md5.new
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class FileContainer:
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def __init__(self, filename, tail = False):
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self.__filename = filename
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self.__tail = tail
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self.__handler = None
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# Try to open the file. Raises an exception if an error occured.
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handler = open(filename)
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stats = os.fstat(handler.fileno())
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self.__ino = stats.st_ino
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try:
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firstLine = handler.readline()
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# Computes the MD5 of the first line.
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self.__hash = md5sum(firstLine).digest()
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# Start at the beginning of file if tail mode is off.
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if tail:
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handler.seek(0, 2)
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self.__pos = handler.tell()
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else:
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self.__pos = 0
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finally:
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handler.close()
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def getFileName(self):
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return self.__filename
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def open(self):
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self.__handler = open(self.__filename)
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# Set the file descriptor to be FD_CLOEXEC
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fd = self.__handler.fileno()
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fcntl.fcntl(fd, fcntl.F_SETFD, fd | fcntl.FD_CLOEXEC)
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firstLine = self.__handler.readline()
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# Computes the MD5 of the first line.
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myHash = md5sum(firstLine).digest()
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stats = os.fstat(self.__handler.fileno())
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# Compare hash and inode
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if self.__hash != myHash or self.__ino != stats.st_ino:
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logSys.info("Log rotation detected for %s" % self.__filename)
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self.__hash = myHash
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self.__ino = stats.st_ino
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self.__pos = 0
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# Sets the file pointer to the last position.
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self.__handler.seek(self.__pos)
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def readline(self):
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if self.__handler == None:
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return ""
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return self.__handler.readline()
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def close(self):
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if not self.__handler == None:
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# Saves the last position.
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self.__pos = self.__handler.tell()
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# Closes the file.
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self.__handler.close()
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self.__handler = None
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##
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# Utils class for DNS and IP handling.
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#
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# This class contains only static methods used to handle DNS and IP
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# addresses.
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import socket, struct
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class DNSUtils:
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IP_CRE = re.compile("^(?:\d{1,3}\.){3}\d{1,3}$")
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#@staticmethod
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def dnsToIp(dns):
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""" Convert a DNS into an IP address using the Python socket module.
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Thanks to Kevin Drapel.
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"""
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try:
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return socket.gethostbyname_ex(dns)[2]
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except socket.gaierror:
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logSys.warn("Unable to find a corresponding IP address for %s"
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% dns)
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return list()
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dnsToIp = staticmethod(dnsToIp)
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#@staticmethod
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def searchIP(text):
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""" Search if an IP address if directly available and return
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it.
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"""
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match = DNSUtils.IP_CRE.match(text)
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if match:
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return match
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else:
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return None
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searchIP = staticmethod(searchIP)
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#@staticmethod
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def isValidIP(string):
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""" Return true if str is a valid IP
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"""
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s = string.split('/', 1)
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try:
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socket.inet_aton(s[0])
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return True
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except socket.error:
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return False
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isValidIP = staticmethod(isValidIP)
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#@staticmethod
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def textToIp(text):
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""" Return the IP of DNS found in a given text.
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"""
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ipList = list()
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# Search for plain IP
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plainIP = DNSUtils.searchIP(text)
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if not plainIP == None:
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plainIPStr = plainIP.group(0)
|
|
if DNSUtils.isValidIP(plainIPStr):
|
|
ipList.append(plainIPStr)
|
|
if not ipList:
|
|
# Try to get IP from possible DNS
|
|
ip = DNSUtils.dnsToIp(text)
|
|
for e in ip:
|
|
ipList.append(e)
|
|
return ipList
|
|
textToIp = staticmethod(textToIp)
|
|
|
|
#@staticmethod
|
|
def cidr(i, n):
|
|
""" Convert an IP address string with a CIDR mask into a 32-bit
|
|
integer.
|
|
"""
|
|
# 32-bit IPv4 address mask
|
|
MASK = 0xFFFFFFFFL
|
|
return ~(MASK >> n) & MASK & DNSUtils.addr2bin(i)
|
|
cidr = staticmethod(cidr)
|
|
|
|
#@staticmethod
|
|
def addr2bin(string):
|
|
""" Convert a string IPv4 address into an unsigned integer.
|
|
"""
|
|
return struct.unpack("!L", socket.inet_aton(string))[0]
|
|
addr2bin = staticmethod(addr2bin)
|
|
|
|
#@staticmethod
|
|
def bin2addr(addr):
|
|
""" Convert a numeric IPv4 address into string n.n.n.n form.
|
|
"""
|
|
return socket.inet_ntoa(struct.pack("!L", addr))
|
|
bin2addr = staticmethod(bin2addr)
|