ISP Config¶
So, you are a ISP and consider fuglu as your scan glue? Here’s what you need to know.
Quarantine GUI¶
Fuglu itself does not ship any kind of quarantine web gui (like Mailwatch, Mailguard etc) for a simple reason: the requirements are too diverse. We are pretty sure you would spend the same amount of time adapting our gui to your needs as writing it from scratch.
A few examples:
- programming language used in the web environment (python, php, perl, ...)
- ACL concepts
- some have a concept of “alias domains”, some don’t
- different antispam/antivirus backends
- different types of quarantine storage, such as
- distributed on scanning machine like mailscanner
- centralized nfs
- stored in a Cassandra/CouchDB cluster
- different types of reports (some want to show every detail to their clients, some others just want them to see number of spam/ham/virus, etc)
- CRM/ERP integration
We recommend you write your user interface the way you like and then let fuglu’s plugin system interface to your gui, usually via a database.
The fuglu ISP plugin¶
Your quarantine gui probaly reads some sort of maillog table which contains a list of all received messages. In fuglu you’d write a plugin which fills this table.
Below is a stripped down example of such a plugin. In a real setup you’d probably have more database fields, add blacklist/whitelist capabilities and support for per domain/per user configuration overrides.
# -*- coding: UTF-8 -*-
from fuglu.shared import ScannerPlugin,DELETE,DUNNO,DEFER,Suspect,string_to_actioncode
import time
import datetime
import os
import fuglu.extensions.sql
import re
from email.header import decode_header
from sqlalchemy import *
from sqlalchemy.ext.declarative import declarative_base
import logging
import socket
MYHOSTNAME=socket.gethostname()
DeclarativeBase = declarative_base()
metadata = DeclarativeBase.metadata
maillog = Table('maillog', metadata,
Column('fugluid', Unicode(255), primary_key=True),
Column('subject', Unicode(255),nullable=False),
Column('from_address', Unicode(255)),
Column('to_address', Unicode(255),nullable=False),
Column('from_domain', Unicode(255)),
Column('to_domain', Unicode(255),nullable=False),
Column('spam', Boolean, default=False),
Column('highspam', Boolean, default=False),
Column('virus', Boolean, default=False),
Column('date', Date, nullable=False),
Column('time', TIME(10), nullable=False),
Column('headers', UnicodeText, nullable=False),
Column('size', Integer,nullable=False),
Column('messageid',Unicode(255),nullable=True),
Column('spamrules',TEXT, nullable=True),
Column('virusinfo',TEXT, nullable=True),
Column('blockedfile', Boolean, nullable=False, default=False),
Column('blockinfo',TEXT, nullable=True),
Column('sascore',Float, nullable=True),
Column('quarantined', Boolean, nullable=False, default=False),
Column('sascantime', Float, nullable=True),
Column('scanhost', Unicode(255),nullable=True),
mysql_engine='InnoDB',
mysql_charset='utf8',
)
class ISPPlugin(ScannerPlugin):
"""ISP Demo Plugin"""
def __init__(self,config,section=None):
ScannerPlugin.__init__(self,config,section)
self.logger=self._logger()
self.requiredvars=((self.section,'dbconnectstring'),)
def needquarantine(self,suspect):
"""return True if message should be quarantined"""
if suspect.get_tag('debug'):
return False
#infected mails can't be whitelisted
if suspect.is_virus():
return True
#blocked attachments can't be whitelisted
blockinfo=suspect.get_tag('FiletypePlugin.errormessage')
if blockinfo!=None:
return True
#whitelisted -> no quarantine
#assuming you have a prevous plugin which sets a 'whitelisted' tag
if suspect.get_tag('whitelisted'):
return False
#blacklisted -> quarantine
#assuming you have a previous plugin which sets a 'blacklisted' tag
if suspect.get_tag('blacklisted'):
return True
#spam -> quarantine
(spam,highspam)=self.is_spam_highspam(suspect)
if spam or highspam:
return True
#ham -> no quarantine
return False
def should_tag_and_send(self,suspect):
"""return true if message should be tagged and sent to the recipient"""
if suspect.is_virus():
return False
blockinfo=suspect.get_tag('FiletypePlugin.errormessage')
if blockinfo!=None:
return False
if suspect.get_tag('blacklisted'):
return False
(spam,highspam)=self.is_spam_highspam(suspect)
#here you could load user/domain individual configs and check if they have disabled the quarantine
#conf=get_filter_config(suspect,self.config.get(self.section,'dbconnectstring'))
#if (spam and conf.deliverspam) or (highspam and conf.deliverhighspam):
# return True
#fallback if quarantine was not available (set by examine method)
if (spam or highspam) and suspect.get_tag("tagandsend"):
return True
return False
def subject_decode(self, encoded_subject):
"""Try to decode subject. Some ugly shaped subjects will remain."""
decoded_subject = u''
for part, encoding in decode_header(encoded_subject):
if encoding is None:
decoded_subject += part.decode(errors='ignore')
else:
decoded_subject += part.decode(encoding,'ignore')
return decoded_subject
def examine(self,suspect):
starttime=time.time()
suspect.set_tag('ispquar',False)
action=DUNNO
if self.needquarantine(suspect):
try:
self.quarantine(suspect)
suspect.set_tag('ispquar',True)
self.logger.info('message quarantined: %s'%suspect.id)
action=DELETE
except Exception,e:
try:
self.logger.warn("quarantine failed")
#you could use a fallback mechanism here, eg. store in a local directory
except Exception,e:
self.logger.error("Could not quarantine message %s : %s -> fallback to tag and send"%(suspect.id,str(e)))
suspect.set_tag("tagandsend",True)
self.maillog(suspect)
self.logger.info('suspect %s logged to database'%suspect.id)
#check for tag&send
if self.should_tag_and_send(suspect):
suspect.set_tag("tagandsend",True)
action=DUNNO
tag="*** SPAM ***"
msgrep=suspect.getMessageRep()
oldsubj=msgrep.get("subject","")
newsubj="%s%s"%(tag,oldsubj)
del msgrep["subject"]
msgrep["subject"]=newsubj
suspect.setMessageRep(msgrep)
endtime=time.time()
difftime=endtime-starttime
suspect.tags['ISPPlugin.time']="%.4f"%difftime
return action
def quarantine(self,suspect):
"""Store message source into quarantine"""
if suspect.get_tag('debug'):
return
#your code here to store the message source in your quarantine (local file, database, ....)
def maillog(self,suspect):
"""Log this message into a mysql database table"""
if suspect.get_tag('debug'):
return
msgrep=suspect.getMessageRep()
headers=re.split('(?:\n\n)|(?:\r\n\r\n)',suspect.getSource(maxbytes=1048576),1)[0]
subj=msgrep['X-Spam-Prev-Subject']
if subj==None:
subj=msgrep['Subject']
if subj==None:
subj=''
try:
subj = self.subject_decode(subj)
except:
self.logger.warning("Could not decode subject - may be truncated")
ts=suspect.timestamp
dt=datetime.datetime.fromtimestamp(ts)
datenow=dt.date()
timenow=dt.time()
session=fuglu.extensions.sql.get_session(self.config.get(self.section,'dbconnectstring'))
metadata.bind=session
#we can't use suspect.is_spam here since spamassassin or other plugins
#(maybe) don't know about individual isp user settings
spam,highspam=self.is_spam_highspam(suspect)
#file block info
blocked=False
blockinfo=suspect.get_tag('FiletypePlugin.errormessage')
if blockinfo!=None:
blocked=True
messageid=msgrep['Message-Id']
#spam rules
ruletext=suspect.get_tag('SAPlugin.report')
#virusinfo: only virusnames separated by space
allviruses=[]
#clam
claminfo=suspect.get_tag('ClamavPlugin.virus')
if claminfo!=None:
for infectedfile,virusname in claminfo.iteritems():
allviruses.append(virusname)
# add other virus scanners here
#remove duplicate viruses
univiruses=set(allviruses)
#remove spaces in virusnames and concatenate into single string
virusinfo=""
for virusname in univiruses:
virusname=virusname.replace(' ','_').strip()
virusinfo=virusinfo+" "+virusname
virusinfo=virusinfo.strip()
#spamscore
try:
sascore=float(suspect.get_tag('SAPlugin.spamscore'))
except:
sascore=None
try:
headers=headers.decode('utf8','replace')
except Exception,e:
self.logger.warning("Could not decode headers to utf8 - output may be truncated")
scantime=suspect.get_tag("SAPlugin.time")
if scantime!=None:
try:
scantime=float(scantime)
except:
scantime=None
data={
'fugluid':suspect.id.decode(),
'from_address':suspect.from_address.decode(),
'to_address':suspect.to_address.decode(),
'from_domain':suspect.from_domain.decode(),
'to_domain':suspect.to_domain.decode(),
'date':datenow,
'time':timenow,
'spam':spam,
'highspam':highspam,
'virus':suspect.is_virus(),
'size':suspect.size,
'subject':subj,
'headers':headers,
'messageid':messageid,
'virusinfo':virusinfo,
'sascore':sascore,
'blockedfile':blocked,
'blockinfo':blockinfo,
'quarantined':suspect.get_tag('ispquar')==True,
'scanhost':MYHOSTNAME,
'sascantime':scantime,
# more fields here....
}
session.execute(maillog.insert().values(**data))
session.close()
def is_spam_highspam(self,suspect):
"""Returns a tuple bool,bool for spam/highspam according to user or domain sa thresholds"""
if suspect.get_tag('whitelisted'):
return (False,False)
try:
score=float( suspect.get_tag('SAPlugin.spamscore'))
except Exception,e:
#subject was not sa scanned
return (False,False)
#here you would load per user/per domain individual spam scores
# user_scpamscore= ...
# user_highspamscore= ...
spam=False
highspam=False
if score>=user_spamscore:
spam=True
if score>=user_highspamscore:
highspam=True
return (spam,highspam)
def __str__(self):
return u'ISP Quarantine/Maillog';
Configuration of other plugins¶
In a ISP setup, your ISP Plugin should be the only one making decisions ( forward / delete ...) based on the results of other plugins.
In your fuglu.conf you’d probably set:
[spam]
defaultlowspamaction=DUNNO
defaulthighspamaction=DUNNO
[virus]
defaultvirusaction=DUNNO
Also, make sure the ISP Plugin is the last plugin
[main]
plugins=clamav,<other virus scanners here>,spamassassin,attachment,<your isp plugin>
So, in case of an infected message, the virus scanner plugins would tag the message as virus but hand it over to later plugins anyway. your isp plugin then reads the tag and returns “DELETE” after the infected message has been quarantined.