475 lines
16 KiB
Python
Executable file
475 lines
16 KiB
Python
Executable file
#!/usr/bin/env python
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# -*- coding: iso-8859-1 -*-
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# The authors of this code are
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# Manuel Sabban <manu@feyd-rautha.org>
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# Frédéric Pauget <pauget@crans.ens-cachan.fr>
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#
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# Copyright (c) 2004 Manuel Sabban, Frédéric Pauget
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#
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# Permission to use, copy, and modify this software with or without fee
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# is hereby granted, provided that this entire notice is included in
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# all source code copies of any software which is or includes a copy or
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# modification of this software.
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#
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# THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
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# IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
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# REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
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# MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
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# PURPOSE.
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""" classe Firewall de Komaz """
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import syslog
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import iptools,config
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import ldap_crans
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from affich_tools import *
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from commands import getstatusoutput
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from iptools import AddrInNet
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syslog.openlog('firewall')
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class ErrorArgument(Exception):
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"""
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User defined exception
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Erreur sur les arguments d'appel du firewall
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"""
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pass
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class ErrorIp(Exception):
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"""
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User defined exception
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Erreur dans les fonctions Ips
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"""
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def __init__(self, ip):
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self.ip=ip
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class ErrorMoreThanOneIp(ErrorIp):
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"""
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User defined exception
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Au moins deux utilisateurs ont la même ip
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"""
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pass
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class IptablesError(Exception):
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""" Gestion des erreurs d'iptables """
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def __init__(self,cmd,err_code,output):
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self.cmd=cmd
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self.err_code=err_code
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self.output=output
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syslog.syslog(syslog.LOG_ERR,"%s : status %s,%s" % (cmd,err_code,output))
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def __str__(self):
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return "%s\n status : %s\n %s" % (self.cmd,self.err_code,self.output)
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def iptables(cmd):
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""" Interface à iptables """
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syslog.syslog(syslog.LOG_INFO,cmd)
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status,output=getstatusoutput("/sbin/iptables "+cmd)
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if status:
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raise IptablesError(cmd,status,output)
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class ErrorNoSuchIp(ErrorIp):
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"""
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User defined exception
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Personne n'a cette ip
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"""
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pass
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class firewall:
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"""
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Structure du firewall :
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table nat :
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PREROUTING (policy par defaut : DROP)
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1) passage par TEST_VIRUS_FLOOD pour tout ce qui n'est pas dans zone_serveur
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2) passage dans RESEAUX_NON_ROUTABLES_DST
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3) passage est paquets venant de l'extérieur dans RESEAUX_NON_ROUTABLES_SRC
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4) on laisse passer vers filter les paquets suivants :
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source ou destination les serveurs de serveurs_crans
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ce qui vient de l'extérieur
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5) passage par TEST_MAC-IP
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TEST_VIRUS_FLOOD droppe les paquets contenant des virus ou les paquets de flood
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RESEAUX_NON_ROUTABLES_DST droppe les paquets dont la destination est non routable
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RESEAUX_NON_ROUTABLES_SRC droppe les paquets dont la source est non routable
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TEST_MAC-IP envoi les bon paquets vers CRANS_VERS_EXT
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CRANS_VERS_EXT
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ACCEPT pour les paquets venant des machines du crans (test port-ip)
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REJECT pour le reste
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table filter :
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FORWARD (policy par defaut : ACCEPT)
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1) passage par BLACKLIST
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2) ce qui a pour source les serveurs de serveurs_crans est dirigé vers SERVEURS_VERS_EXT
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3) ce qui a pour destination les serveurs de serveurs_crans est dirigé EXT_VERS_SERVEURS
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4) tout ce qui vient de l'interface externe est dirigé vers EXT_VERS_CRANS
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5) ce qui a pour source les serveurs de serveurs_crans est dirigé vers EXT_VERS_CRANS
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BLACKLIST fitre des ip blacklistées (reject)
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EXT_VERS_CRANS
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ACCEPT pour les paquets vers les machines du crans (test port-ip)
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REJECT pour le reste
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EXT_VERS_SERVEURS et SERVEURS_VERS_EXT
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ACCEPT pour bon mac-ip-port
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REJECT pour le reste
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"""
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zone_serveur="138.231.136.0/28"
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eth_ext = "eth2"
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# Ports ouverts
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ports_default = { 'tcp_EXT_VERS_CRANS' : [ '22' ],
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'tcp_CRANS_VERS_EXT': [ ':79', '81:134', '136', '140:444', '446:'],
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'udp_EXT_VERS_CRANS' : [ ],
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'udp_CRANS_VERS_EXT': [ ':136','140:'] }
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mac_wifi = '00:0c:f1:fa:f1:4b'
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limit = " -m limit --limit 10/s --limit-burst 10 "
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log_template = '-m limit --limit 1/s --limit-burst 1 -j LOG --log-level notice --log-prefix '
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filtre_flood = '-m dstlimit --dstlimit 20 --dstlimit-mode srcip-dstip --dstlimit-name flood'
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liste_reseaux_non_routables = [ '1.0.0.0/8','2.0.0.0/8','5.0.0.0/8','7.0.0.0/8',\
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'10.0.0.0/8','14.0.0.0/8','23.0.0.0/8','27.0.0.0/8','31.0.0.0/8','36.0.0.0/8',\
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'37.0.0.0/8','39.0.0.0/8','41.0.0.0/8','42.0.0.0/8','71.0.0.0/8','72.0.0.0/8',\
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'73.0.0.0/8','74.0.0.0/8','75.0.0.0/8','76.0.0.0/8','77.0.0.0/8','78.0.0.0/8',\
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'79.0.0.0/8','89.0.0.0/8','90.0.0.0/8','91.0.0.0/8','92.0.0.0/8','93.0.0.0/8',\
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'94.0.0.0/8','95.0.0.0/8','96.0.0.0/8','97.0.0.0/8','98.0.0.0/8','99.0.0.0/8',\
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'100.0.0.0/8','101.0.0.0/8','102.0.0.0/8','103.0.0.0/8','104.0.0.0/8',\
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'105.0.0.0/8','106.0.0.0/8','107.0.0.0/8','108.0.0.0/8','109.0.0.0/8',\
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'110.0.0.0/8','111.0.0.0/8','112.0.0.0/8','113.0.0.0/8','114.0.0.0/8',\
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'115.0.0.0/8','116.0.0.0/8','117.0.0.0/8','118.0.0.0/8','119.0.0.0/8',\
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'120.0.0.0/8','121.0.0.0/8','122.0.0.0/8','123.0.0.0/8','124.0.0.0/8',\
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'125.0.0.0/8','126.0.0.0/8','127.0.0.0/8','169.254.0.0/16','172.16.0.0/12',\
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'173.0.0.0/8','174.0.0.0/8','175.0.0.0/8','176.0.0.0/8','177.0.0.0/8',\
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'178.0.0.0/8','179.0.0.0/8','180.0.0.0/8','181.0.0.0/8','182.0.0.0/8',\
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'183.0.0.0/8','184.0.0.0/8','185.0.0.0/8','186.0.0.0/8','187.0.0.0/8',\
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'189.0.0.0/8','190.0.0.0/8','192.168.0.0/16','197.0.0.0/8','223.0.0.0/8',\
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'224.0.0.0/4','240.0.0.0/4']
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ports_virus = { 'tcp' : [ 135, 445 ] , 'udp' : [] }
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machines = []
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debug = 1
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def __machines(self) :
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""" Liste des machines du crans """
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if not self.machines :
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self.anim = anim(" Interrogation de la base LDAP")
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self.machines = ldap_crans.crans_ldap().search('ip=*')['machine']
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print OK
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return self.machines
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def start(self) :
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""" Construction du firewall """
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cprint('Démarrage firewall','gras')
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# Préliminaires
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if not self.__machines() or self.stop() :
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print "Abandon"
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return
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self.anim = anim(' Construction structure de la table nat')
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for chaine in [ 'LOG_VIRUS', 'LOG_FLOOD', 'TEST_VIRUS_FLOOD' , 'TEST_MAC-IP' , 'RESEAUX_NON_ROUTABLES_SRC', 'RESEAUX_NON_ROUTABLES_DST' ] :
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iptables('-t nat -N %s' % chaine)
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try :
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iptables("-t nat -P PREROUTING ACCEPT")
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iptables("-t nat -A PREROUTING -i lo -j ACCEPT")
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iptables("-t nat -A PREROUTING -s ! %s -j TEST_VIRUS_FLOOD" % self.zone_serveur)
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iptables("-t nat -A PREROUTING -j RESEAUX_NON_ROUTABLES_DST")
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iptables("-t nat -A PREROUTING -i %s -j RESEAUX_NON_ROUTABLES_SRC" % self.eth_ext )
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iptables("-t nat -A PREROUTING -d %s -j ACCEPT" % self.zone_serveur )
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iptables("-t nat -A PREROUTING -s %s -j ACCEPT" % self.zone_serveur )
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iptables("-t nat -A PREROUTING -i %s -j ACCEPT" % self.eth_ext )
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iptables("-t nat -A PREROUTING -j TEST_MAC-IP")
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iptables("-t nat -P PREROUTING DROP")
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print OK
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self.anim = anim(' Construction structure de la table filter')
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for chaine in [ 'EXT_VERS_SERVEURS', 'SERVEURS_VERS_EXT' , 'EXT_VERS_CRANS', 'CRANS_VERS_EXT', 'BLACKLIST_SRC', 'BLACKLIST_DST' ] :
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iptables('-N %s' % chaine)
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iptables("-A FORWARD -i lo -j ACCEPT")
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iptables("-A FORWARD -p icmp -j ACCEPT")
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iptables("-A FORWARD -i %s -j BLACKLIST_DST" % self.eth_ext )
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iptables("-A FORWARD -o %s -j BLACKLIST_SRC" % self.eth_ext )
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iptables("-A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT")
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iptables("-A FORWARD -i %s -d %s -j EXT_VERS_SERVEURS" % (self.eth_ext, self.zone_serveur) )
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iptables("-A FORWARD -o %s -s %s -j SERVEURS_VERS_EXT" % (self.eth_ext, self.zone_serveur) )
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iptables("-A FORWARD -i %s -j EXT_VERS_CRANS" % self.eth_ext )
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iptables("-A FORWARD -o %s -j CRANS_VERS_EXT" % self.eth_ext )
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print OK
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except IptablesError, c :
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print ERREUR
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if self.debug : print c
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self.stop()
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return 1
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except :
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print ERREUR
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self.stop()
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if self.debug :
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import traceback
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traceback.print_exc()
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return 1
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for tache in [ self.log_chaines, self.test_virus_flood, self.reseaux_non_routables,
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self.blacklist , self.serveurs_vers_ext, self.ext_vers_serveurs,
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self.crans_vers_ext, self.ext_vers_crans, self.test_mac_ip ] :
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try :
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tache()
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except IptablesError, c :
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self.anim.reinit()
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print ERREUR
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if self.debug : print c
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except :
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self.anim.reinit()
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print ERREUR
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import traceback
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if self.debug : traceback.print_exc()
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def log_chaines(self) :
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""" Construction des chaines de log (LOG_VIRUS et LOG_FLOOD) """
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self.anim = anim(' Création des chaines de log')
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for filtre in [ 'VIRUS', 'FLOOD' ] :
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# Vidage de la chaîne
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iptables('-t nat -F LOG_%s' % filtre)
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iptables('-t nat -A LOG_%s %s %s:' % (filtre, self.log_template, filtre.capitalize()) )
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iptables('-t nat -A LOG_%s -j DROP' % filtre )
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self.anim.cycle()
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self.anim.reinit()
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print OK
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def reseaux_non_routables(self) :
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""" Construction de RESEAUX_NON_ROUTABLES_{DST,SRC} """
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self.anim = anim(' Filtrage ip non routables',len(self.liste_reseaux_non_routables))
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for reseau in self.liste_reseaux_non_routables :
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iptables("-t nat -A RESEAUX_NON_ROUTABLES_DST -d %s -j DROP" % reseau)
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iptables("-t nat -A RESEAUX_NON_ROUTABLES_SRC -s %s -j DROP" % reseau)
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self.anim.cycle()
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self.anim.reinit()
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print OK
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def test_virus_flood(self) :
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""" Construction de la chaîne TEST_VIRUS """
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iptables('-t nat -F TEST_VIRUS_FLOOD')
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self.anim = anim(' Filtrage virus et floods')
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for proto, ports in self.ports_virus.items() :
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for port in ports :
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iptables('-t nat -A TEST_VIRUS_FLOOD -p %s --dport %s -j LOG_VIRUS' % (proto, port) )
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self.anim.cycle()
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iptables('-t nat -A TEST_VIRUS_FLOOD %s -j RETURN' % self.filtre_flood) # Les limites en négatif ca ne marche pas.
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self.anim.cycle()
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iptables('-t nat -A TEST_VIRUS_FLOOD -j LOG_FLOOD')
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self.anim.reinit()
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print OK
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def stop(self):
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""" Arrête le firewall """
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self.anim = anim(" Arrêt du firewall")
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try :
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iptables("-t nat -P PREROUTING ACCEPT")
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iptables("-F")
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iptables("-t nat -F")
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iptables("-X")
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iptables("-t nat -X")
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print OK
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return 0
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except IptablesError, c :
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print ERREUR
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if self.debug : print c
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except :
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print ERREUR
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if self.debug :
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import traceback
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traceback.print_exc()
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return 1
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def test_mac_ip(self) :
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""" Reconstruit la correspondance MAC-IP des machines des adhérents """
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self.anim = anim(' Construction de la chaîne TEST_MAC-IP',len(self.__machines())+1)
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iptables("-t nat -P PREROUTING ACCEPT")
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iptables("-t nat -F TEST_MAC-IP")
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self.anim.cycle()
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try:
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for machine in self.__machines() :
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self.__test_mac_ip(machine)
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self.anim.cycle()
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iptables("-t nat -P PREROUTING DROP")
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self.anim.reinit()
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print OK
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except IptablesError, c :
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self.anim.reinit()
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print ERREUR
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if self.debug : print c
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except :
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self.anim.reinit()
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print ERREUR
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if self.debug :
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import traceback
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traceback.print_exc()
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def serveurs_vers_ext(self) :
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""" Reconstruit la chaine SERVEURS_VERS_EXT """
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if self.__build_chaine('SERVEURS_VERS_EXT', self.__serveurs_vers_ext) :
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self.anim.reinit()
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print OK
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def ext_vers_serveurs(self) :
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""" Reconstruit la chaine EXT_VERS_SERVEURS """
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if self.__build_chaine('EXT_VERS_SERVEURS', self.__ext_vers_serveurs) :
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self.anim.reinit()
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print OK
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def crans_vers_ext(self) :
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""" Reconstruit la chaine CRANS_VERS_EXT """
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self.__build_chaine_adherent('CRANS_VERS_EXT',self.__crans_vers_ext)
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def ext_vers_crans(self) :
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""" Reconstruit la chaine EXT_VERS_CRANS """
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self.__build_chaine_adherent('EXT_VERS_CRANS',self.__ext_vers_crans)
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def __build_chaine_adherent(self,chaine,methode):
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if self.__build_chaine(chaine, methode) :
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# Défauts
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self.anim.reinit()
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for proto in [ 'tcp' , 'udp' ] :
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for port in self.ports_default["%s_%s" % ( proto, chaine) ] :
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self.anim.cycle()
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iptables("-I %s -p %s --dport %s -j ACCEPT" % (chaine, proto,port) )
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self.anim.reinit()
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print OK
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def __build_chaine(self,chaine, methode) :
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self.anim = anim(' Construction de la chaîne %s' % chaine,len(self.__machines())+1)
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iptables("-F %s" % chaine)
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self.anim.cycle()
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try:
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for machine in self.__machines() :
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methode(machine)
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self.anim.cycle()
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iptables("-A %s -j REJECT" % chaine)
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self.anim.reinit()
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return 1
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except IptablesError, c :
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self.anim.reinit()
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print ERREUR
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if self.debug : print c
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except :
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self.anim.reinit()
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print ERREUR
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if self.debug :
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import traceback
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traceback.print_exc()
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def add_machine(self,machine):
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self.__serveurs_vers_ext(machine)
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self.__ext_vers_serveurs(machine)
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self.__crans_vers_ext(machine)
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self.__ext_vers_crans(machine)
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self.__test_mac_ip(machine)
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def __serveurs_vers_ext(self,machine):
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ip=machine.ip()
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if not AddrInNet(ip,self.zone_serveur):
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# C'est une machine adhérent, rien à faire ici
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return
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mac = machine.mac()
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ports = { 'tcp' : machine.portTCPin(),
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'udp' : machine.portUDPin() }
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for proto in [ 'tcp', 'udp' ] :
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for port in ports[proto].split() :
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iptables("-I SERVEURS_VERS_EXT -s %s -p %s --dport %s -m mac --mac-source %s -j ACCEPT" \
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%(ip,proto,port,mac))
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def __ext_vers_serveurs(self,machine):
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ip=machine.ip()
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if not AddrInNet(ip,self.zone_serveur):
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# C'est une machine adhérent, rien à faire ici
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return
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ports = { 'tcp' : machine.portTCPin(),
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'udp' : machine.portUDPin() }
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for proto in [ 'tcp', 'udp' ] :
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for port in ports[proto].split() :
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iptables("-I EXT_VERS_SERVEURS -d %s -p %s --dport %s -j ACCEPT"\
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%(ip,proto,port))
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def __crans_vers_ext(self,machine):
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ip=machine.ip()
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if AddrInNet(ip,self.zone_serveur):
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# C'est un serveur, rien à faire ici
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return
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ports = { 'tcp' : machine.portTCPout(),
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'udp' : machine.portUDPout() }
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for proto in [ 'tcp', 'udp' ] :
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for port in ports[proto].split() :
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iptables("-I CRANS_VERS_EXT -s %s -p %s --dport %s -j ACCEPT" \
|
||
%(ip,proto,port))
|
||
|
||
def __ext_vers_crans(self,machine):
|
||
ip=machine.ip()
|
||
if AddrInNet(ip,self.zone_serveur):
|
||
# C'est un serveur, rien à faire ici
|
||
return
|
||
|
||
ports = { 'tcp' : machine.portTCPin(),
|
||
'udp' : machine.portUDPin() }
|
||
|
||
for proto in [ 'tcp', 'udp' ] :
|
||
for port in ports[proto].split() :
|
||
iptables("-I EXT_VERS_CRANS -d %s -p %s --dport %s -j ACCEPT" \
|
||
%(ip,proto,port))
|
||
|
||
def __test_mac_ip(self,machine):
|
||
ip=machine.ip()
|
||
mac=machine.mac()
|
||
if machine.ipsec():
|
||
# Machine wifi, c'est la mac de Nectaris
|
||
iptables("-t nat -A TEST_MAC-IP -s "+\
|
||
"%s -m mac --mac-source %s -j ACCEPT"%(ip,self.mac_wifi))
|
||
else:
|
||
# Machine fixe
|
||
iptables("-t nat -A TEST_MAC-IP -s "+\
|
||
"%s -m mac --mac-source %s -j ACCEPT"%(ip,mac))
|
||
|
||
def blacklist(self):
|
||
""" Construit les chaines de blackliste (BLACKLIST_{DST,SRC}) """
|
||
self.anim = anim(" Contruction blackliste")
|
||
iptables('-F BLACKLIST_DST')
|
||
iptables('-F BLACKLIST_SRC')
|
||
|
||
blacklist=[]
|
||
search=ldap_crans.crans_ldap().search('blacklist=*&paiement=%s'%ldap_crans.ann_scol)
|
||
for entite in search['adherent']+search['club']+search['machine']:
|
||
self.anim.cycle()
|
||
sanctions = entite.blacklist_actif()
|
||
if 'upload' in sanctions or 'warez' in sanctions :
|
||
if search.__class__ == ldap_crans.machine:
|
||
blacklist+=[entite]
|
||
else:
|
||
blacklist+=entite.machines()
|
||
|
||
for machine in blacklist:
|
||
iptables("-A BLACKLIST_DST -d %s -j REJECT" % machine.ip())
|
||
iptables("-A BLACKLIST_SRC -s %s -j REJECT" % machine.ip())
|
||
|
||
self.anim.reinit()
|
||
print OK
|
||
|
||
def del_entree(self,ip):
|
||
""" Détruit toutes les occurences à l'IP dans le firewall """
|
||
for table in [ 'filter' , 'nat' ] :
|
||
for chaine in iptables("-t %s -L -n --line-numbers" % table).split('Chain ') :
|
||
nom_chaine = chaine.split(' ',1)[0]
|
||
to_del=[]
|
||
for regle in chaine.split('\n')[1:] :
|
||
# On regarde les règles une à une
|
||
regle = regle.split()
|
||
if ip in regle :
|
||
# Règle à dértuire
|
||
to_del.append(int(regle[0]))
|
||
# Destruction des règles de cette chaîne
|
||
to_del.sort()
|
||
to_del.reverse()
|
||
for i in to_del :
|
||
iptables('-t %s -D %s %s' % (table, nom_chaine, i) )
|
||
|