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#
# logactio - simple framework for doing configured action on certain
# log file events
#
# Copyright 2012 - 2015 David Sommerseth <dazo@eurephia.org>
#
# This program 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, version 2
# of the License.
#
# This program 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 this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# For the avoidance of doubt the "preferred form" of this code is one which
# is in an open unpatent encumbered format. Where cryptographic key signing
# forms part of the process of creating an executable the information
# including keys needed to generate an equivalently functional executable
# are deemed to be part of the source code.
#
import hashlib, time
class ThresholdType_Rule(object):
def __init__(self, params):
if "threshold" not in params:
raise ValueError("Missing required 'threshold' parameter")
self.__threshold = int(params["threshold"])
self.__timeframe = params["timeframe"] and int(params["timeframe"]) or None
self.__ratelimit = params["ratelimit"] and int(params["ratelimit"]) or None
self.__lastseen = 0
self.__lastsent = 0
self.__currentcount = 0
def CheckThreshold(self, alert, notused_regexmatch):
now = int(time.time())
self.__currentcount += 1
ret = (self.__threshold == 0
or ((self.__currentcount % self.__threshold == 0)
and (self.__timeframe is None
or now <= (self.__lastseen + self.__timeframe)))
and (self.__ratelimit is None or now > (self.__lastsent + self.__ratelimit)))
if (self.__timeframe and (self.__lastseen > 0)
and (now >= (self.__lastseen + self.__timeframe))):
# If the time-frame have timed out, reset it
self.__lastseen = 0
else:
self.__lastseen = now
return ret
def ClearTimeTrackers(self, notused_regexmatch):
self.__lastseen = 0
self.__lastsent = 0
def GetThreshold(self):
return self.__threshold
def GetCurrentCount(self, rgmatch):
return self.__currentcount
class ThresholdType_Exact(object):
def __init__(self, params):
self.__matchedgroups = {}
self.__threshold = int(params["threshold"])
self.__timeframe = params["timeframe"] and int(params["timeframe"]) or None
self.__ratelimit = params["ratelimit"] and int(params["ratelimit"]) or None
def __gen_hash(self, regexmatch):
v = "|".join(regexmatch)
return hashlib.sha384(v.encode('utf-8')).hexdigest()
def CheckThreshold(self, alert, regexmatch):
now = int(time.time())
ret = False
# If threshold is 0 or 1, then we process all records
if self.__threshold < 2:
return True
# Check if we have a regexmatch on this from earlier checks
rghash = self.__gen_hash(regexmatch)
if rghash in self.__matchedgroups:
lastevent = self.__matchedgroups[rghash]
lastevent["count"] += 1
ret = ((lastevent["count"] % self.__threshold == 0)
and (self.__timeframe is None
or now <= (lastevent["lastseen"] + self.__timeframe))
and (self.__ratelimit is None or now > (lastevent["lastsent"] + self.__ratelimit)))
try:
if (self.__timeframe and 'lastseen' in lastevent
and (lastevent["lastseen"] > 0)
and (now >= (lastevent["lastseen"] + self.__timeframe))):
# If the time-frame have timed out, reset it
self.__lastseen = 0
else:
self.__lastseen = now
except KeyError as e:
self.__lastseen = now
else:
# Not seen before, register it as a new one
self.__matchedgroups[rghash] = {
"count": 1,
"lastseen": now,
"lastsent": 0
}
ret = (1 % self.__threshold == 0)
return ret
def ClearTimeTrackers(self, regexmatch):
rghash = self.__gen_hash(regexmatch)
if rghash in self.__matchedgroups:
self.__matchedgroups[rghash]["lasteen"] = 0
self.__matchedgroups[rghash]["lastsent"] = 0
def GetThreshold(self):
return self.__threshold
def GetCurrentCount(self, regexmatch):
rghash = self.__gen_hash(regexmatch)
if rghash in self.__matchedgroups:
return self.__matchedgroups[rghash]["count"]
else:
return 0
class ThresholdWatch(object):
WATCHTYPE_RULE = 1
WATCHTYPE_EXACT = 2
def __init__(self, watchtype, params):
self.__watchtype = watchtype
if watchtype == self.WATCHTYPE_RULE:
self.__thresholdtype = ThresholdType_Rule(params)
elif watchtype == self.WATCHTYPE_EXACT:
self.__thresholdtype = ThresholdType_Exact(params)
else:
raise ValueError("Invalid watchtype parameter")
def CheckThreshold(self, alert, regexmatch):
return self.__thresholdtype.CheckThreshold(alert, regexmatch)
def ClearTimeTrackers(self, regexmatch):
self.__thresholdtype.ClearTimeTrackers(regexmatch)
def GetThreshold(self):
return self.__thresholdtype.GetThreshold()
def GetCurrentCount(self, regexmatch):
return self.__thresholdtype.GetCurrentCount(regexmatch)
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