fail2ban/fail2ban/server/filter.py

1248 lines
35 KiB
Python

# 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 and Fail2Ban Contributors"
__copyright__ = "Copyright (c) 2004 Cyril Jaquier, 2011-2013 Yaroslav Halchenko"
__license__ = "GPL"
import codecs
import datetime
import fcntl
import logging
import os
import re
import sys
import time
from .failmanager import FailManagerEmpty, FailManager
from .ipdns import DNSUtils, IPAddr
from .observer import Observers
from .ticket import FailTicket
from .jailthread import JailThread
from .datedetector import DateDetector, validateTimeZone
from .mytime import MyTime
from .failregex import FailRegex, Regex, RegexException
from .action import CommandAction
from .utils import Utils
from ..helpers import getLogger, PREFER_ENC
# 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 Filter(JailThread):
##
# Constructor.
#
# Initialize the filter object with default values.
# @param jail the jail object
def __init__(self, jail, useDns='warn'):
JailThread.__init__(self)
## The jail which contains this filter.
self.jail = jail
## The failures manager.
self.failManager = FailManager()
## Regular expression pre-filtering matching the failures.
self.__prefRegex = None
## The regular expression list matching the failures.
self.__failRegex = list()
## The regular expression list with expressions to ignore.
self.__ignoreRegex = list()
## Use DNS setting
self.setUseDns(useDns)
## The amount of time to look back.
self.__findTime = 600
## Ignore own IPs flag:
self.__ignoreSelf = True
## The ignore IP list.
self.__ignoreIpList = []
## Size of line buffer
self.__lineBufferSize = 1
## Line buffer
self.__lineBuffer = []
## Store last time stamp, applicable for multi-line
self.__lastTimeText = ""
self.__lastDate = None
## if set, treat log lines without explicit time zone to be in this time zone
self.__logtimezone = None
## External command
self.__ignoreCommand = False
## Default or preferred encoding (to decode bytes from file or journal):
self.__encoding = PREFER_ENC
## Cache temporary holds failures info (used by multi-line for wrapping e. g. conn-id to host):
self.__mlfidCache = None
## Error counter (protected, so can be used in filter implementations)
## if it reached 100 (at once), run-cycle will go idle
self._errors = 0
## return raw host (host is not dns):
self.returnRawHost = False
## check each regex (used for test purposes):
self.checkAllRegex = False
## if true ignores obsolete failures (failure time < now - findTime):
self.checkFindTime = True
## Ticks counter
self.ticks = 0
self.dateDetector = DateDetector()
logSys.debug("Created %s", self)
def __repr__(self):
return "%s(%r)" % (self.__class__.__name__, self.jail)
@property
def jailName(self):
return (self.jail is not None and self.jail.name or "~jailless~")
def clearAllParams(self):
""" Clear all lists/dicts parameters (used by reloading)
"""
self.delFailRegex()
self.delIgnoreRegex()
self.delIgnoreIP()
def reload(self, begin=True):
""" Begin or end of reloading resp. refreshing of all parameters
"""
if begin:
self.clearAllParams()
if hasattr(self, 'getLogPaths'):
self._reload_logs = dict((k, 1) for k in self.getLogPaths())
else:
if hasattr(self, '_reload_logs'):
# if it was not reloaded - remove obsolete log file:
for path in self._reload_logs:
self.delLogPath(path)
delattr(self, '_reload_logs')
@property
def mlfidCache(self):
if self.__mlfidCache:
return self.__mlfidCache
self.__mlfidCache = Utils.Cache(maxCount=100, maxTime=5*60)
return self.__mlfidCache
@property
def prefRegex(self):
return self.__prefRegex
@prefRegex.setter
def prefRegex(self, value):
if value:
self.__prefRegex = Regex(value, useDns=self.__useDns)
else:
self.__prefRegex = None
##
# Add a regular expression which matches the failure.
#
# The regular expression can also match any other pattern than failures
# and thus can be used for many purporse.
# @param value the regular expression
def addFailRegex(self, value):
multiLine = self.getMaxLines() > 1
try:
regex = FailRegex(value, prefRegex=self.__prefRegex, multiline=multiLine,
useDns=self.__useDns)
self.__failRegex.append(regex)
except RegexException as e:
logSys.error(e)
raise e
def delFailRegex(self, index=None):
try:
# clear all:
if index is None:
del self.__failRegex[:]
return
# delete by index:
del self.__failRegex[index]
except IndexError:
logSys.error("Cannot remove regular expression. Index %d is not "
"valid", index)
##
# Get the regular expressions as list.
#
# @return the regular expression list
def getFailRegex(self):
return [regex.getRegex() for regex in self.__failRegex]
##
# Add the regular expression which matches the failure.
#
# The regular expression can also match any other pattern than failures
# and thus can be used for many purpose.
# @param value the regular expression
def addIgnoreRegex(self, value):
try:
regex = Regex(value, useDns=self.__useDns)
self.__ignoreRegex.append(regex)
except RegexException as e:
logSys.error(e)
raise e
def delIgnoreRegex(self, index=None):
try:
# clear all:
if index is None:
del self.__ignoreRegex[:]
return
# delete by index:
del self.__ignoreRegex[index]
except IndexError:
logSys.error("Cannot remove regular expression. Index %d is not "
"valid", index)
##
# Get the regular expression which matches the failure.
#
# @return the regular expression
def getIgnoreRegex(self):
ignoreRegex = list()
for regex in self.__ignoreRegex:
ignoreRegex.append(regex.getRegex())
return ignoreRegex
##
# Set the Use DNS mode
# @param value the usedns mode
def setUseDns(self, value):
if isinstance(value, bool):
value = {True: 'yes', False: 'no'}[value]
value = value.lower() # must be a string by now
if not (value in ('yes', 'warn', 'no', 'raw')):
logSys.error("Incorrect value %r specified for usedns. "
"Using safe 'no'", value)
value = 'no'
logSys.debug("Setting usedns = %s for %s", value, self)
self.__useDns = value
##
# Get the usedns mode
# @return the usedns mode
def getUseDns(self):
return self.__useDns
##
# Set the time needed to find a failure.
#
# This value tells the filter how long it has to take failures into
# account.
# @param value the time
def setFindTime(self, value):
value = MyTime.str2seconds(value)
self.__findTime = value
self.failManager.setMaxTime(value)
logSys.info(" findtime: %s", value)
##
# Get the time needed to find a failure.
#
# @return the time
def getFindTime(self):
return self.__findTime
##
# Set the date detector pattern, removing Defaults
#
# @param pattern the date template pattern
def setDatePattern(self, pattern):
if pattern is None:
self.dateDetector = None
return
else:
dd = DateDetector()
dd.default_tz = self.__logtimezone
if not isinstance(pattern, (list, tuple)):
pattern = filter(bool, map(str.strip, re.split('\n+', pattern)))
for pattern in pattern:
dd.appendTemplate(pattern)
self.dateDetector = dd
##
# Get the date detector pattern, or Default Detectors if not changed
#
# @return pattern of the date template pattern
def getDatePattern(self):
if self.dateDetector is not None:
templates = self.dateDetector.templates
# lazy template init, by first match
if not len(templates) or len(templates) > 2:
return None, "Default Detectors"
elif len(templates):
if hasattr(templates[0], "pattern"):
pattern = templates[0].pattern
else:
pattern = None
return pattern, templates[0].name
return None
##
# Set the log default time zone
#
# @param tz the symbolic timezone (for now fixed offset only: UTC[+-]HHMM)
def setLogTimeZone(self, tz):
validateTimeZone(tz); # avoid setting of wrong value, but hold original
self.__logtimezone = tz
if self.dateDetector: self.dateDetector.default_tz = self.__logtimezone
##
# Get the log default timezone
#
# @return symbolic timezone (a string)
def getLogTimeZone(self):
return self.__logtimezone
##
# Set the maximum retry value.
#
# @param value the retry value
def setMaxRetry(self, value):
self.failManager.setMaxRetry(value)
logSys.info(" maxRetry: %s", value)
##
# Get the maximum retry value.
#
# @return the retry value
def getMaxRetry(self):
return self.failManager.getMaxRetry()
##
# Set the maximum line buffer size.
#
# @param value the line buffer size
def setMaxLines(self, value):
if int(value) <= 0:
raise ValueError("maxlines must be integer greater than zero")
self.__lineBufferSize = int(value)
logSys.info(" maxLines: %i", self.__lineBufferSize)
##
# Get the maximum line buffer size.
#
# @return the line buffer size
def getMaxLines(self):
return self.__lineBufferSize
##
# Set the log file encoding
#
# @param encoding the encoding used with log files
def setLogEncoding(self, encoding):
if encoding.lower() == "auto":
encoding = PREFER_ENC
codecs.lookup(encoding) # Raise LookupError if invalid codec
self.__encoding = encoding
logSys.info(" encoding: %s", encoding)
return encoding
##
# Get the log file encoding
#
# @return log encoding value
def getLogEncoding(self):
return self.__encoding
##
# 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): # pragma: no cover
raise Exception("run() is abstract")
##
# Set external command, for ignoredips
#
def setIgnoreCommand(self, command):
self.__ignoreCommand = command
##
# Get external command, for ignoredips
#
def getIgnoreCommand(self):
return self.__ignoreCommand
##
# Ban an IP - http://blogs.buanzo.com.ar/2009/04/fail2ban-patch-ban-ip-address-manually.html
# Arturo 'Buanzo' Busleiman <buanzo@buanzo.com.ar>
#
# to enable banip fail2ban-client BAN command
def addBannedIP(self, ip):
if not isinstance(ip, IPAddr):
ip = IPAddr(ip)
if self.inIgnoreIPList(ip):
logSys.warning('Requested to manually ban an ignored IP %s. User knows best. Proceeding to ban it.', ip)
unixTime = MyTime.time()
self.failManager.addFailure(FailTicket(ip, unixTime), self.failManager.getMaxRetry())
# Perform the banning of the IP now.
try: # pragma: no branch - exception is the only way out
while True:
ticket = self.failManager.toBan(ip)
self.jail.putFailTicket(ticket)
except FailManagerEmpty:
self.failManager.cleanup(MyTime.time())
return ip
##
# Ignore own IP/DNS.
#
@property
def ignoreSelf(self):
return self.__ignoreSelf
@ignoreSelf.setter
def ignoreSelf(self, value):
self.__ignoreSelf = value
##
# Add an IP/DNS to the ignore list.
#
# IP addresses in the ignore list are not taken into account
# when finding failures. CIDR mask and DNS are also accepted.
# @param ip IP address to ignore
def addIgnoreIP(self, ipstr):
# An empty string is always false
if ipstr == "":
return
# Create IP address object
ip = IPAddr(ipstr)
# Avoid exact duplicates
if ip in self.__ignoreIpList:
logSys.warn(" Ignore duplicate %r (%r), already in ignore list", ip, ipstr)
return
# log and append to ignore list
logSys.debug(" Add %r to ignore list (%r)", ip, ipstr)
self.__ignoreIpList.append(ip)
def delIgnoreIP(self, ip=None):
# clear all:
if ip is None:
del self.__ignoreIpList[:]
return
# delete by ip:
logSys.debug(" Remove %r from ignore list", ip)
self.__ignoreIpList.remove(ip)
def logIgnoreIp(self, ip, log_ignore, ignore_source="unknown source"):
if log_ignore:
logSys.info("[%s] Ignore %s by %s", self.jailName, ip, ignore_source)
def getIgnoreIP(self):
return self.__ignoreIpList
##
# Check if IP address/DNS is in the ignore list.
#
# Check if the given IP address matches an IP address/DNS or a CIDR
# mask in the ignore list.
# @param ip IP address object
# @return True if IP address is in ignore list
def inIgnoreIPList(self, ip, log_ignore=False):
if not isinstance(ip, IPAddr):
ip = IPAddr(ip)
# check own IPs should be ignored and 'ip' is self IP:
if self.__ignoreSelf and ip in DNSUtils.getSelfIPs():
return True
for net in self.__ignoreIpList:
# check if the IP is covered by ignore IP
if ip.isInNet(net):
self.logIgnoreIp(ip, log_ignore, ignore_source=("ip" if net.isValid else "dns"))
return True
if self.__ignoreCommand:
command = CommandAction.replaceTag(self.__ignoreCommand, { 'ip': ip } )
logSys.debug('ignore command: %s', command)
ret, ret_ignore = CommandAction.executeCmd(command, success_codes=(0, 1))
ret_ignore = ret and ret_ignore == 0
self.logIgnoreIp(ip, log_ignore and ret_ignore, ignore_source="command")
return ret_ignore
return False
def processLine(self, line, date=None):
"""Split the time portion from log msg and return findFailures on them
"""
if date:
tupleLine = line
else:
l = line.rstrip('\r\n')
logSys.log(7, "Working on line %r", line)
(timeMatch, template) = self.dateDetector.matchTime(l)
if timeMatch:
tupleLine = (
l[:timeMatch.start(1)],
l[timeMatch.start(1):timeMatch.end(1)],
l[timeMatch.end(1):],
(timeMatch, template)
)
else:
tupleLine = (l, "", "", None)
# save last line (lazy convert of process line tuple to string on demand):
self.processedLine = lambda: "".join(tupleLine[::2])
return self.findFailure(tupleLine, date)
def processLineAndAdd(self, line, date=None):
"""Processes the line for failures and populates failManager
"""
try:
for element in self.processLine(line, date):
ip = element[1]
unixTime = element[2]
fail = element[3]
logSys.debug("Processing line with time:%s and ip:%s",
unixTime, ip)
if self.inIgnoreIPList(ip, log_ignore=True):
continue
logSys.info(
"[%s] Found %s - %s", self.jailName, ip, datetime.datetime.fromtimestamp(unixTime).strftime("%Y-%m-%d %H:%M:%S")
)
tick = FailTicket(ip, unixTime, data=fail)
self.failManager.addFailure(tick)
# report to observer - failure was found, for possibly increasing of it retry counter (asynchronous)
if Observers.Main is not None:
Observers.Main.add('failureFound', self.failManager, self.jail, tick)
# reset (halve) error counter (successfully processed line):
if self._errors:
self._errors //= 2
except Exception as e:
logSys.error("Failed to process line: %r, caught exception: %r", line, e,
exc_info=logSys.getEffectiveLevel()<=logging.DEBUG)
# incr common error counter:
self.commonError()
def commonError(self):
# incr error counter, stop processing (going idle) after 100th error :
self._errors += 1
# sleep a little bit (to get around time-related errors):
time.sleep(self.sleeptime)
if self._errors >= 100:
logSys.error("Too many errors at once (%s), going idle", self._errors)
self._errors //= 2
self.idle = True
##
# Returns true if the line should be ignored.
#
# Uses ignoreregex.
# @param line: the line
# @return: a boolean
def ignoreLine(self, tupleLines):
for ignoreRegexIndex, ignoreRegex in enumerate(self.__ignoreRegex):
ignoreRegex.search(tupleLines)
if ignoreRegex.hasMatched():
return ignoreRegexIndex
return None
def _mergeFailure(self, mlfid, fail, failRegex):
mlfidFail = self.mlfidCache.get(mlfid) if self.__mlfidCache else None
# if multi-line failure id (connection id) known:
if mlfidFail:
mlfidGroups = mlfidFail[1]
# update - if not forget (disconnect/reset):
if not fail.get('mlfforget'):
mlfidGroups.update(fail)
else:
self.mlfidCache.unset(mlfid) # remove cached entry
# merge with previous info:
fail2 = mlfidGroups.copy()
fail2.update(fail)
if not fail.get('nofail'): # be sure we've correct current state
try:
del fail2['nofail']
except KeyError:
pass
fail2["matches"] = fail.get("matches", []) + failRegex.getMatchedTupleLines()
fail = fail2
elif not fail.get('mlfforget'):
mlfidFail = [self.__lastDate, fail]
self.mlfidCache.set(mlfid, mlfidFail)
if fail.get('nofail'):
fail["matches"] = failRegex.getMatchedTupleLines()
return fail
##
# Finds the failure in a line given split into time and log parts.
#
# Uses the failregex pattern to find it and timeregex in order
# to find the logging time.
# @return a dict with IP and timestamp.
def findFailure(self, tupleLine, date=None):
failList = list()
returnRawHost = self.returnRawHost
cidr = IPAddr.CIDR_UNSPEC
if self.__useDns == "raw":
returnRawHost = True
cidr = IPAddr.CIDR_RAW
# Checks if we mut ignore this line.
if self.ignoreLine([tupleLine[::2]]) is not None:
# The ignoreregex matched. Return.
logSys.log(7, "Matched ignoreregex and was \"%s\" ignored",
"".join(tupleLine[::2]))
return failList
timeText = tupleLine[1]
if date:
self.__lastTimeText = timeText
self.__lastDate = date
elif timeText:
dateTimeMatch = self.dateDetector.getTime(timeText, tupleLine[3])
if dateTimeMatch is None:
logSys.error("findFailure failed to parse timeText: %s", timeText)
date = self.__lastDate
else:
# Lets get the time part
date = dateTimeMatch[0]
self.__lastTimeText = timeText
self.__lastDate = date
else:
timeText = self.__lastTimeText or "".join(tupleLine[::2])
date = self.__lastDate
if self.checkFindTime and date is not None and date < MyTime.time() - self.getFindTime():
logSys.log(5, "Ignore line since time %s < %s - %s",
date, MyTime.time(), self.getFindTime())
return failList
if self.__lineBufferSize > 1:
orgBuffer = self.__lineBuffer = (
self.__lineBuffer + [tupleLine[:3]])[-self.__lineBufferSize:]
else:
orgBuffer = self.__lineBuffer = [tupleLine[:3]]
logSys.log(5, "Looking for match of %r", self.__lineBuffer)
# Pre-filter fail regex (if available):
preGroups = {}
if self.__prefRegex:
if logSys.getEffectiveLevel() <= logging.HEAVYDEBUG: # pragma: no cover
logSys.log(5, " Looking for prefregex %r", self.__prefRegex.getRegex())
self.__prefRegex.search(self.__lineBuffer)
if not self.__prefRegex.hasMatched():
logSys.log(5, " Prefregex not matched")
return failList
preGroups = self.__prefRegex.getGroups()
logSys.log(7, " Pre-filter matched %s", preGroups)
repl = preGroups.get('content')
# Content replacement:
if repl:
del preGroups['content']
self.__lineBuffer = [('', '', repl)]
# Iterates over all the regular expressions.
for failRegexIndex, failRegex in enumerate(self.__failRegex):
if logSys.getEffectiveLevel() <= logging.HEAVYDEBUG: # pragma: no cover
logSys.log(5, " Looking for failregex %r", failRegex.getRegex())
failRegex.search(self.__lineBuffer, orgBuffer)
if not failRegex.hasMatched():
continue
# The failregex matched.
logSys.log(7, " Matched %s", failRegex)
# Checks if we must ignore this match.
if self.ignoreLine(failRegex.getMatchedTupleLines()) \
is not None:
# The ignoreregex matched. Remove ignored match.
self.__lineBuffer = failRegex.getUnmatchedTupleLines()
logSys.log(7, " Matched ignoreregex and was ignored")
if not self.checkAllRegex:
break
else:
continue
if date is None:
logSys.warning(
"Found a match for %r but no valid date/time "
"found for %r. Please try setting a custom "
"date pattern (see man page jail.conf(5)). "
"If format is complex, please "
"file a detailed issue on"
" https://github.com/fail2ban/fail2ban/issues "
"in order to get support for this format.",
"\n".join(failRegex.getMatchedLines()), timeText)
continue
self.__lineBuffer = failRegex.getUnmatchedTupleLines()
# retrieve failure-id, host, etc from failure match:
try:
raw = returnRawHost
if preGroups:
fail = preGroups.copy()
fail.update(failRegex.getGroups())
else:
fail = failRegex.getGroups()
# first try to check we have mlfid case (caching of connection id by multi-line):
mlfid = fail.get('mlfid')
if mlfid is not None:
fail = self._mergeFailure(mlfid, fail, failRegex)
# bypass if no-failure case:
if fail.get('nofail'):
logSys.log(7, "Nofail by mlfid %r in regex %s: %s",
mlfid, failRegexIndex, fail.get('mlfforget', "waiting for failure"))
if not self.checkAllRegex: return failList
else:
# matched lines:
fail["matches"] = fail.get("matches", []) + failRegex.getMatchedTupleLines()
# failure-id:
fid = fail.get('fid')
# ip-address or host:
host = fail.get('ip4')
if host is not None:
cidr = IPAddr.FAM_IPv4
raw = True
else:
host = fail.get('ip6')
if host is not None:
cidr = IPAddr.FAM_IPv6
raw = True
if host is None:
host = fail.get('dns')
if host is None:
# first try to check we have mlfid case (cache connection id):
if fid is None and mlfid is None:
# if no failure-id also (obscure case, wrong regex), throw error inside getFailID:
fid = failRegex.getFailID()
host = fid
cidr = IPAddr.CIDR_RAW
# if mlfid case (not failure):
if host is None:
logSys.log(7, "No failure-id by mlfid %r in regex %s: %s",
mlfid, failRegexIndex, fail.get('mlfforget', "waiting for identifier"))
if not self.checkAllRegex: return failList
ips = [None]
# if raw - add single ip or failure-id,
# otherwise expand host to multiple ips using dns (or ignore it if not valid):
elif raw:
ip = IPAddr(host, cidr)
# check host equal failure-id, if not - failure with complex id:
if fid is not None and fid != host:
ip = IPAddr(fid, IPAddr.CIDR_RAW)
ips = [ip]
# otherwise, try to use dns conversion:
else:
ips = DNSUtils.textToIp(host, self.__useDns)
# append failure with match to the list:
for ip in ips:
failList.append([failRegexIndex, ip, date, fail])
if not self.checkAllRegex:
break
except RegexException as e: # pragma: no cover - unsure if reachable
logSys.error(e)
return failList
def status(self, flavor="basic"):
"""Status of failures detected by filter.
"""
ret = [("Currently failed", self.failManager.size()),
("Total failed", self.failManager.getFailTotal())]
return ret
class FileFilter(Filter):
def __init__(self, jail, **kwargs):
Filter.__init__(self, jail, **kwargs)
## The log file path.
self.__logs = dict()
self.__autoSeek = dict()
##
# Add a log file path
#
# @param path log file path
def addLogPath(self, path, tail=False, autoSeek=True):
if path in self.__logs:
if hasattr(self, '_reload_logs') and path in self._reload_logs:
del self._reload_logs[path]
else:
logSys.error(path + " already exists")
else:
log = FileContainer(path, self.getLogEncoding(), tail)
db = self.jail.database
if db is not None:
lastpos = db.addLog(self.jail, log)
if lastpos and not tail:
log.setPos(lastpos)
self.__logs[path] = log
logSys.info("Added logfile: %r (pos = %s, hash = %s)" , path, log.getPos(), log.getHash())
if autoSeek:
# if default, seek to "current time" - "find time":
if isinstance(autoSeek, bool):
autoSeek = MyTime.time() - self.getFindTime()
self.__autoSeek[path] = autoSeek
self._addLogPath(path) # backend specific
def _addLogPath(self, path):
# nothing to do by default
# to be overridden by backends
pass
##
# Delete a log path
#
# @param path the log file to delete
def delLogPath(self, path):
try:
log = self.__logs.pop(path)
except KeyError:
return
db = self.jail.database
if db is not None:
db.updateLog(self.jail, log)
logSys.info("Removed logfile: %r", path)
self._delLogPath(path)
return
def _delLogPath(self, path): # pragma: no cover - overwritten function
# nothing to do by default
# to be overridden by backends
pass
##
# Get the log file names
#
# @return log paths
def getLogPaths(self):
return self.__logs.keys()
##
# Get the log containers
#
# @return log containers
def getLogs(self):
return self.__logs.values()
##
# Get the count of log containers
#
# @return count of log containers
def getLogCount(self):
return len(self.__logs)
##
# Check whether path is already monitored.
#
# @param path The path
# @return True if the path is already monitored else False
def containsLogPath(self, path):
return path in self.__logs
##
# Set the log file encoding
#
# @param encoding the encoding used with log files
def setLogEncoding(self, encoding):
encoding = super(FileFilter, self).setLogEncoding(encoding)
for log in self.__logs.itervalues():
log.setEncoding(encoding)
def getLog(self, path):
return self.__logs.get(path, None)
##
# Gets all the failure in the log file.
#
# Gets all the failure in the log file which are newer than
# MyTime.time()-self.findTime. When a failure is detected, a FailTicket
# is created and is added to the FailManager.
def getFailures(self, filename):
log = self.getLog(filename)
if log is None:
logSys.error("Unable to get failures in %s", filename)
return False
# We should always close log (file), otherwise may be locked (log-rotate, etc.)
try:
# Try to open log file.
try:
has_content = log.open()
# see http://python.org/dev/peps/pep-3151/
except IOError as e:
logSys.error("Unable to open %s", filename)
if e.errno != 2: # errno.ENOENT
logSys.exception(e)
return False
except OSError as e: # pragma: no cover - requires race condition to tigger this
logSys.error("Error opening %s", filename)
logSys.exception(e)
return False
except Exception as e: # pragma: no cover - Requires implemention error in FileContainer to generate
logSys.error("Internal error in FileContainer open method - please report as a bug to https://github.com/fail2ban/fail2ban/issues")
logSys.exception(e)
return False
# seek to find time for first usage only (prevent performance decline with polling of big files)
if self.__autoSeek.get(filename):
startTime = self.__autoSeek[filename]
del self.__autoSeek[filename]
# prevent completely read of big files first time (after start of service),
# initial seek to start time using half-interval search algorithm:
try:
self.seekToTime(log, startTime)
except Exception as e: # pragma: no cover
logSys.error("Error during seek to start time in \"%s\"", filename)
raise
logSys.exception(e)
return False
if has_content:
while not self.idle:
line = log.readline()
if not line or not self.active:
# The jail reached the bottom or has been stopped
break
self.processLineAndAdd(line)
finally:
log.close()
db = self.jail.database
if db is not None:
db.updateLog(self.jail, log)
return True
##
# Seeks to line with date (search using half-interval search algorithm), to start polling from it
#
def seekToTime(self, container, date, accuracy=3):
fs = container.getFileSize()
if logSys.getEffectiveLevel() <= logging.DEBUG:
logSys.debug("Seek to find time %s (%s), file size %s", date,
datetime.datetime.fromtimestamp(date).strftime("%Y-%m-%d %H:%M:%S"), fs)
minp = container.getPos()
maxp = fs
tryPos = minp
lastPos = -1
foundPos = 0
foundTime = None
cntr = 0
unixTime = None
movecntr = accuracy
while maxp > minp:
if tryPos is None:
pos = int(minp + (maxp - minp) / 2)
else:
pos, tryPos = tryPos, None
# because container seek will go to start of next line (minus CRLF):
pos = max(0, pos-2)
seekpos = pos = container.seek(pos)
cntr += 1
# within next 5 lines try to find any legal datetime:
lncntr = 5;
dateTimeMatch = None
nextp = None
while True:
line = container.readline()
if not line:
break
(timeMatch, template) = self.dateDetector.matchTime(line)
if timeMatch:
dateTimeMatch = self.dateDetector.getTime(
line[timeMatch.start():timeMatch.end()],
(timeMatch, template))
else:
nextp = container.tell()
if nextp > maxp:
pos = seekpos
break
pos = nextp
if not dateTimeMatch and lncntr:
lncntr -= 1
continue
break
# not found at this step - stop searching
if dateTimeMatch:
unixTime = dateTimeMatch[0]
if unixTime >= date:
if foundTime is None or unixTime <= foundTime:
foundPos = pos
foundTime = unixTime
if pos == maxp:
pos = seekpos
if pos < maxp:
maxp = pos
else:
if foundTime is None or unixTime >= foundTime:
foundPos = pos
foundTime = unixTime
if nextp is None:
nextp = container.tell()
pos = nextp
if pos > minp:
minp = pos
# if we can't move (position not changed)
if pos == lastPos:
movecntr -= 1
if movecntr <= 0:
break
# we have found large area without any date mached
# or end of search - try min position (because can be end of previous line):
if minp != lastPos:
lastPos = tryPos = minp
continue
break
lastPos = pos
# always use smallest pos, that could be found:
foundPos = container.seek(minp, False)
container.setPos(foundPos)
if logSys.getEffectiveLevel() <= logging.DEBUG:
logSys.debug("Position %s from %s, found time %s (%s) within %s seeks", lastPos, fs, foundTime,
(datetime.datetime.fromtimestamp(foundTime).strftime("%Y-%m-%d %H:%M:%S") if foundTime is not None else ''), cntr)
def status(self, flavor="basic"):
"""Status of Filter plus files being monitored.
"""
ret = super(FileFilter, self).status(flavor=flavor)
path = self.__logs.keys()
ret.append(("File list", path))
return ret
def stop(self):
"""Stop monitoring of log-file(s)
"""
# stop files monitoring:
for path in self.__logs.keys():
self.delLogPath(path)
# stop thread:
super(Filter, self).stop()
##
# FileContainer class.
#
# This class manages a file handler and takes care of log rotation detection.
# In order to detect log rotation, the hash (MD5) of the first line of the file
# is computed and compared to the previous hash of this line.
try:
import hashlib
try:
md5sum = hashlib.md5
# try to use it (several standards like FIPS forbid it):
md5sum(' ').hexdigest()
except: # pragma: no cover
md5sum = hashlib.sha1
except ImportError: # pragma: no cover
# hashlib was introduced in Python 2.5. For compatibility with those
# elderly Pythons, import from md5
import md5
md5sum = md5.new
class FileContainer:
def __init__(self, filename, encoding, tail = False):
self.__filename = filename
self.setEncoding(encoding)
self.__tail = tail
self.__handler = None
# Try to open the file. Raises an exception if an error occurred.
handler = open(filename, 'rb')
stats = os.fstat(handler.fileno())
self.__ino = stats.st_ino
try:
firstLine = handler.readline()
# Computes the MD5 of the first line.
self.__hash = md5sum(firstLine).hexdigest()
# Start at the beginning of file if tail mode is off.
if tail:
handler.seek(0, 2)
self.__pos = handler.tell()
else:
self.__pos = 0
finally:
handler.close()
def getFileName(self):
return self.__filename
def getFileSize(self):
return os.path.getsize(self.__filename);
def setEncoding(self, encoding):
codecs.lookup(encoding) # Raises LookupError if invalid
self.__encoding = encoding
def getEncoding(self):
return self.__encoding
def getHash(self):
return self.__hash
def getPos(self):
return self.__pos
def setPos(self, value):
self.__pos = value
def open(self):
self.__handler = open(self.__filename, 'rb')
# Set the file descriptor to be FD_CLOEXEC
fd = self.__handler.fileno()
flags = fcntl.fcntl(fd, fcntl.F_GETFD)
fcntl.fcntl(fd, fcntl.F_SETFD, flags | fcntl.FD_CLOEXEC)
# Stat the file before even attempting to read it
stats = os.fstat(self.__handler.fileno())
if not stats.st_size:
# yoh: so it is still an empty file -- nothing should be
# read from it yet
# print "D: no content -- return"
return False
firstLine = self.__handler.readline()
# Computes the MD5 of the first line.
myHash = md5sum(firstLine).hexdigest()
## print "D: fn=%s hashes=%s/%s inos=%s/%s pos=%s rotate=%s" % (
## self.__filename, self.__hash, myHash, stats.st_ino, self.__ino, self.__pos,
## self.__hash != myHash or self.__ino != stats.st_ino)
## sys.stdout.flush()
# Compare hash and inode
if self.__hash != myHash or self.__ino != stats.st_ino:
logSys.log(logging.MSG, "Log rotation detected for %s", self.__filename)
self.__hash = myHash
self.__ino = stats.st_ino
self.__pos = 0
# Sets the file pointer to the last position.
self.__handler.seek(self.__pos)
return True
def seek(self, offs, endLine=True):
h = self.__handler
# seek to given position
h.seek(offs, 0)
# goto end of next line
if offs and endLine:
h.readline()
# get current real position
return h.tell()
def tell(self):
# get current real position
return self.__handler.tell()
@staticmethod
def decode_line(filename, enc, line):
try:
return line.decode(enc, 'strict')
except (UnicodeDecodeError, UnicodeEncodeError) as e:
global _decode_line_warn
lev = logging.DEBUG
if _decode_line_warn.get(filename, 0) <= MyTime.time():
lev = logging.WARNING
_decode_line_warn[filename] = MyTime.time() + 24*60*60
logSys.log(lev,
"Error decoding line from '%s' with '%s'."
" Consider setting logencoding=utf-8 (or another appropriate"
" encoding) for this jail. Continuing"
" to process line ignoring invalid characters: %r",
filename, enc, line)
# decode with replacing error chars:
line = line.decode(enc, 'replace')
return line
def readline(self):
if self.__handler is None:
return ""
return FileContainer.decode_line(
self.getFileName(), self.getEncoding(), self.__handler.readline())
def close(self):
if not self.__handler is None:
# Saves the last position.
self.__pos = self.__handler.tell()
# Closes the file.
self.__handler.close()
self.__handler = None
## print "D: Closed %s with pos %d" % (handler, self.__pos)
## sys.stdout.flush()
_decode_line_warn = {}
##
# JournalFilter class.
#
# Base interface class for systemd journal filters
class JournalFilter(Filter): # pragma: systemd no cover
def clearAllParams(self):
super(JournalFilter, self).clearAllParams()
self.delJournalMatch()
def addJournalMatch(self, match): # pragma: no cover - Base class, not used
pass
def delJournalMatch(self, match=None): # pragma: no cover - Base class, not used
pass
def getJournalMatch(self, match): # pragma: no cover - Base class, not used
return []