Stuart Gathman
75 lines
2.1 KiB
Python
75 lines
2.1 KiB
Python
import time
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import shelve
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import thread
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import logging
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import urllib
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log = logging.getLogger('milter.greylist')
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def quoteAddress(s):
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'''Quote an address so that it's safe to store in the file-system.
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Address can either be a domain name, or local part.
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Returns the quoted address.'''
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s = urllib.quote(s, '@_-+~!.%')
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if s.startswith('.'): s = '%2e' + s[1:]
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return s
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class Record(object):
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__slots__ = ( 'firstseen', 'lastseen', 'umis', 'cnt' )
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def __init__(self):
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now = time.time()
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self.firstseen = now
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self.lastseen = now
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self.cnt = 0
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self.umis = None
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class Greylist(object):
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def __init__(self,dbname,grey_time=10,grey_expire=4,grey_retain=36):
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self.ignoreLastByte = False
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self.greylist_time = grey_time * 60 # minutes
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self.greylist_expire = grey_expire * 3600 # hours
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self.greylist_retain = grey_retain * 24 * 3600 # days
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self.dbp = shelve.open(dbname,'c',protocol=2)
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self.lock = thread.allocate_lock()
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def check(self,ip,sender,recipient):
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"Return number of allowed messages for greylist triple."
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sender = quoteAddress(sender)
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recipient = quoteAddress(recipient)
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key = ip + ':' + sender + ':' + recipient
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self.lock.acquire()
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try:
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dbp = self.dbp
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try:
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r = dbp[key]
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now = time.time()
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if now > r.lastseen + self.greylist_retain:
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# expired
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log.debug('Expired greylist: %s',key)
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r = Record()
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elif now < r.firstseen + self.greylist_time + 5:
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# still greylisted
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log.debug('Early greylist: %s',key)
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#r = Record()
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r.lastseen = now
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elif r.cnt or now < r.firstseen + self.greylist_expire:
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# in greylist window or active
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r.lastseen = now
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r.cnt += 1
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log.debug('Active greylist(%d): %s',r.cnt,key)
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else:
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# passed greylist window
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log.debug('Late greylist: %s',key)
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r = Record()
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dbp[key] = r
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except:
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r = Record()
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dbp[key] = r
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dbp.sync()
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finally:
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self.lock.release()
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return r.cnt
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