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from __future__ import print_function
import time
import shelve
import thread
import logging
import urllib
log = logging.getLogger('milter.greylist')
def quoteAddress(s):
'''Quote an address so that it's safe to store in the file-system.
Address can either be a domain name, or local part.
Returns the quoted address.'''
s = urllib.quote(s, '@_-+~!.%')
if s.startswith('.'): s = '%2e' + s[1:]
return s
class Record(object):
__slots__ = ( 'firstseen', 'lastseen', 'umis', 'cnt' )
def __init__(self,timeinc=0):
now = time.time() + timeinc
self.firstseen = now
self.lastseen = now
self.cnt = 0
self.umis = None
def __str__(self):
return "Grey[%s:%s:%s:%d]" % (
time.ctime(self.firstseen),time.ctime(self.lastseen),
self.umis,self.cnt
)
class Greylist(object):
def __init__(self,dbname,grey_time=10,grey_expire=4,grey_retain=36):
self.ignoreLastByte = False
self.greylist_time = grey_time * 60 # minutes
self.greylist_expire = grey_expire * 3600 # hours
self.greylist_retain = grey_retain * 24 * 3600 # days
self.dbp = shelve.open(dbname,'c',protocol=2)
self.lock = thread.allocate_lock()
def export_csv(self,fp,timeinc=0):
"Export records to csv."
import csv
dbp = self.dbp
w = csv.writer(fp)
now = time.time() + timeinc
for key, r in dbp.iteritems():
if now > r.lastseen + self.greylist_retain: continue
ip,sender,recipient = key.rsplit(':',2)
w.writerow([ip,sender,recipient,r.firstseen,r.lastseen,r.cnt,r.umis])
def clean(self,timeinc=0):
"Delete records past the retention limit."
now = time.time() + timeinc
cnt = 0
dbp = self.dbp
for key, r in dbp.iteritems():
#print(key,r,time.ctime(now))
if now > r.lastseen + self.greylist_retain:
self.lock.acquire()
try:
r = dbp[key]
now = time.time() + timeinc
if now > r.lastseen + self.greylist_retain:
del dbp[key]
cnt += 1
finally:
self.lock.release()
return cnt
def check(self,ip,sender,recipient,timeinc=0):
"Return number of allowed messages for greylist triple."
sender = quoteAddress(sender)
recipient = quoteAddress(recipient)
key = ip + ':' + sender + ':' + recipient
self.lock.acquire()
try:
dbp = self.dbp
try:
r = dbp[key]
now = time.time() + timeinc
if now > r.lastseen + self.greylist_retain:
# expired
log.debug('Expired greylist: %s',key)
r = Record(timeinc)
elif now < r.firstseen + self.greylist_time + 5:
# still greylisted
log.debug('Early greylist: %s',key)
#r = Record(timeinc)
r.lastseen = now
elif r.cnt or now < r.firstseen + self.greylist_expire:
# in greylist window or active
r.lastseen = now
r.cnt += 1
log.debug('Active greylist(%d): %s',r.cnt,key)
else:
# passed greylist window
log.debug('Late greylist: %s',key)
r = Record(timeinc)
dbp[key] = r
except:
r = Record(timeinc)
dbp[key] = r
dbp.sync()
finally:
self.lock.release()
return r.cnt
def close(self):
self.dbp.close()
if __name__ == '__main__':
import sys
g = Greylist(sys.argv[1],5,24,36)
try:
g.export_csv(sys.stdout)
finally: g.close()
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