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# 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
#
__author__ = "Cyril Jaquier"
__copyright__ = "Copyright (c) 2004 Cyril Jaquier"
__license__ = "GPL"
from threading import Lock
from .ticket import BanTicket
from .mytime import MyTime
from ..helpers import getLogger, logging
# Gets the instance of the logger.
logSys = getLogger(__name__)
##
# Banning Manager.
#
# Manage the banned IP addresses. Convert FailTicket to BanTicket.
# This class is mainly used by the Action class.
class BanManager:
##
# Constructor.
#
# Initialize members with default values.
def __init__(self):
## Mutex used to protect the ban list.
self.__lock = Lock()
## The ban list.
self.__banList = dict()
## The amount of time an IP address gets banned.
self.__banTime = 600
## Total number of banned IP address
self.__banTotal = 0
## The time for next unban process (for performance and load reasons):
self._nextUnbanTime = BanTicket.MAX_TIME
##
# Set the ban time.
#
# Set the amount of time an IP address get banned.
# @param value the time
def setBanTime(self, value):
self.__banTime = int(value)
##
# Get the ban time.
#
# Get the amount of time an IP address get banned.
# @return the time
def getBanTime(self):
return self.__banTime
##
# Set the total number of banned address.
#
# @param value total number
def setBanTotal(self, value):
self.__banTotal = value
##
# Get the total number of banned address.
#
# @return the total number
def getBanTotal(self):
return self.__banTotal
##
# Returns a copy of the IP list.
#
# @return IP list
def getBanList(self, ordered=False, withTime=False):
if not ordered:
return list(self.__banList.keys())
with self.__lock:
lst = []
for ticket in self.__banList.values():
eob = ticket.getEndOfBanTime(self.__banTime)
lst.append((ticket,eob))
lst.sort(key=lambda t: t[1])
t2s = MyTime.time2str
if withTime:
return ['%s \t%s + %d = %s' % (
t[0].getID(),
t2s(t[0].getTime()), t[0].getBanTime(self.__banTime), t2s(t[1])
) for t in lst]
return [t[0].getID() for t in lst]
##
# Returns a iterator to ban list (used in reload, so idle).
#
# @return ban list iterator
def __iter__(self):
# ensure iterator is safe - traverse over the list in snapshot created within lock (GIL):
return iter(list(self.__banList.values()))
##
# Returns normalized value
#
# @return value or "unknown" if value is None or empty string
@staticmethod
def handleBlankResult(value):
if value is None or len(value) == 0:
return "unknown"
else:
return value
##
# Returns Cymru DNS query information
#
# @return {"asn": [], "country": [], "rir": []} dict for self.__banList IPs
def getBanListExtendedCymruInfo(self, timeout=10):
return_dict = {"asn": [], "country": [], "rir": []}
if not hasattr(self, 'dnsResolver'):
global dns
try:
import dns.exception
import dns.resolver
resolver = dns.resolver.Resolver()
resolver.lifetime = timeout
resolver.timeout = timeout / 2
self.dnsResolver = resolver
except ImportError as e: # pragma: no cover
logSys.error("dnspython package is required but could not be imported")
return_dict["error"] = repr(e)
return_dict["asn"].append("error")
return_dict["country"].append("error")
return_dict["rir"].append("error")
return return_dict
# get ips in lock:
with self.__lock:
banIPs = [banData.getIP() for banData in list(self.__banList.values())]
# get cymru info:
try:
for ip in banIPs:
# Reference: https://www.team-cymru.com/IP-ASN-mapping.html#dns
question = ip.getPTR(
"origin.asn.cymru.com" if ip.isIPv4
else "origin6.asn.cymru.com"
)
try:
resolver = self.dnsResolver
answers = resolver.query(question, "TXT")
if not answers:
raise ValueError("No data retrieved")
asns = set()
countries = set()
rirs = set()
for rdata in answers:
asn, net, country, rir, changed =\
[answer.strip("'\" ") for answer in rdata.to_text().split("|")]
asn = self.handleBlankResult(asn)
country = self.handleBlankResult(country)
rir = self.handleBlankResult(rir)
asns.add(self.handleBlankResult(asn))
countries.add(self.handleBlankResult(country))
rirs.add(self.handleBlankResult(rir))
return_dict["asn"].append(', '.join(sorted(asns)))
return_dict["country"].append(', '.join(sorted(countries)))
return_dict["rir"].append(', '.join(sorted(rirs)))
except dns.resolver.NXDOMAIN:
return_dict["asn"].append("nxdomain")
return_dict["country"].append("nxdomain")
return_dict["rir"].append("nxdomain")
except (dns.exception.DNSException, dns.resolver.NoNameservers, dns.exception.Timeout) as dnse: # pragma: no cover
logSys.error("DNSException %r querying Cymru for %s TXT", dnse, question)
if logSys.level <= logging.DEBUG:
logSys.exception(dnse)
return_dict["error"] = repr(dnse)
break
except Exception as e: # pragma: no cover
logSys.error("Unhandled Exception %r querying Cymru for %s TXT", e, question)
if logSys.level <= logging.DEBUG:
logSys.exception(e)
return_dict["error"] = repr(e)
break
except Exception as e: # pragma: no cover
logSys.error("Failure looking up extended Cymru info: %s", e)
if logSys.level <= logging.DEBUG:
logSys.exception(e)
return_dict["error"] = repr(e)
return return_dict
##
# Returns list of Banned ASNs from Cymru info
#
# Use getBanListExtendedCymruInfo() to provide cymru_info
#
# @return list of Banned ASNs
def geBanListExtendedASN(self, cymru_info):
try:
return [asn for asn in cymru_info["asn"]]
except Exception as e:
logSys.error("Failed to lookup ASN")
logSys.exception(e)
return []
##
# Returns list of Banned Countries from Cymru info
#
# Use getBanListExtendedCymruInfo() to provide cymru_info
#
# @return list of Banned Countries
def geBanListExtendedCountry(self, cymru_info):
try:
return [country for country in cymru_info["country"]]
except Exception as e:
logSys.error("Failed to lookup Country")
logSys.exception(e)
return []
##
# Returns list of Banned RIRs from Cymru info
#
# Use getBanListExtendedCymruInfo() to provide cymru_info
#
# @return list of Banned RIRs
def geBanListExtendedRIR(self, cymru_info):
try:
return [rir for rir in cymru_info["rir"]]
except Exception as e:
logSys.error("Failed to lookup RIR")
logSys.exception(e)
return []
##
# Add a ban ticket.
#
# Add a BanTicket instance into the ban list.
# @param ticket the ticket
# @return True if the IP address is not in the ban list
def addBanTicket(self, ticket, reason={}):
eob = ticket.getEndOfBanTime(self.__banTime)
if eob < MyTime.time():
reason['expired'] = 1
return False
with self.__lock:
# check already banned
fid = ticket.getID()
oldticket = self.__banList.get(fid)
if oldticket:
reason['ticket'] = oldticket
# if new time for end of ban is larger than already banned end-time:
if eob > oldticket.getEndOfBanTime(self.__banTime):
# we have longest ban - set new (increment) ban time
reason['prolong'] = 1
btm = ticket.getBanTime(self.__banTime)
# if not permanent:
if btm != -1:
diftm = ticket.getTime() - oldticket.getTime()
if diftm > 0:
btm += diftm
oldticket.setBanTime(btm)
return False
# not yet banned - add new one:
self.__banList[fid] = ticket
self.__banTotal += 1
ticket.incrBanCount()
# correct next unban time:
if self._nextUnbanTime > eob:
self._nextUnbanTime = eob
return True
##
# Get the size of the ban list.
#
# @return the size
def size(self):
return len(self.__banList)
##
# Check if a ticket is in the list.
#
# Check if a BanTicket with a given IP address is already in the
# ban list.
# @param ticket the ticket
# @return True if a ticket already exists
def _inBanList(self, ticket):
return ticket.getID() in self.__banList
##
# Get the list of IP address to unban.
#
# Return a list of BanTicket which need to be unbanned.
# @param time the time
# @return the list of ticket to unban
def unBanList(self, time, maxCount=0x7fffffff):
with self.__lock:
# Check next unban time:
nextUnbanTime = self._nextUnbanTime
if nextUnbanTime > time:
return list()
# Gets the list of ticket to remove (thereby correct next unban time).
unBanList = {}
nextUnbanTime = BanTicket.MAX_TIME
for fid,ticket in self.__banList.items():
# current time greater as end of ban - timed out:
eob = ticket.getEndOfBanTime(self.__banTime)
if time > eob:
unBanList[fid] = ticket
if len(unBanList) >= maxCount: # stop search cycle, so reset back the next check time
nextUnbanTime = self._nextUnbanTime
break
elif nextUnbanTime > eob:
nextUnbanTime = eob
self._nextUnbanTime = nextUnbanTime
# Removes tickets.
if len(unBanList):
if len(unBanList) / 2.0 <= len(self.__banList) / 3.0:
# few as 2/3 should be removed - remove particular items:
for fid in unBanList.keys():
del self.__banList[fid]
else:
# create new dictionary without items to be deleted:
self.__banList = dict((fid,ticket) for fid,ticket in self.__banList.items() \
if fid not in unBanList)
# return list of tickets:
return list(unBanList.values())
##
# Flush the ban list.
#
# Get the ban list and initialize it with an empty one.
# @return the complete ban list
def flushBanList(self):
with self.__lock:
uBList = list(self.__banList.values())
self.__banList = dict()
return uBList
##
# Gets the ticket for the specified ID (most of the time it is IP-address).
#
# @return the ticket or False.
def getTicketByID(self, fid):
with self.__lock:
try:
# Return the ticket after removing (popping)
# if from the ban list.
return self.__banList.pop(fid)
except KeyError:
pass
return None # if none found
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