scripts/gestion/gen_confs/firewall4/komaz.py
Pierre-Elliott Bécue 17e4baac12 [firewall] On permet aux serveurs d'être joignables sur le port 22
* Et on corrige deux typos dans utils.py
2014-05-15 14:09:12 +02:00

560 lines
25 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
import utils
import base
from utils import pretty_print, OK, anim
from base import dev
class firewall(base.firewall_routeur):
"""Pare-feu du serveur komaz, routeur principal de l'association"""
def __init__(self):
super(self.__class__, self).__init__()
self.reloadable.update({
'log_all' : self.log_all,
'admin_vlan' : self.admin_vlan,
'clamp_mss' : self.clamp_mss,
'ingress_filtering' : self.ingress_filtering,
'ssh_on_https' : self.ssh_on_https,
'connexion_secours' : self.connexion_secours,
'connexion_appartement' : self.connexion_appartement,
'blacklist_soft' : self.blacklist_soft,
'blacklist_upload' : self.blacklist_upload,
'reseaux_non_routable' : self.reseaux_non_routable,
'filtrage_ports' : self.filtrage_ports,
'limitation_debit' : self.limitation_debit,
'limit_ssh_connexion' : self.limit_ssh_connexion,
'tunnel_6in4' : self.tunnel_6in4,
})
self.use_ipset.extend([self.blacklist_soft, self.blacklist_upload, self.reseaux_non_routable])
self.use_tc.extend([self.limitation_debit])
self.ipset['reseaux_non_routable'] = {
'deny' : base.Ipset("RESEAUX-NON-ROUTABLE-DENY","nethash"),
'allow' : base.Ipset("RESEAUX-NON-ROUTABLE-ALLOW","nethash"),
}
self.ipset['blacklist'].update({
'soft' : base.Ipset("BLACKLIST-SOFT","ipmap","--from 138.231.136.0 --to 138.231.151.255"),
'upload' : base.Ipset("BLACKLIST-UPLOAD","ipmap","--from 138.231.136.0 --to 138.231.151.255"),
})
def blacklist_maj(self, ips):
"""Mise à jour des blacklistes"""
self.blacklist_hard_maj(ips)
self.blacklist_soft_maj(ips)
self.blacklist_upload_maj(ips)
def blacklists(self, table=None, fill_ipset=False, apply=False):
self.blacklist_hard(table=table, fill_ipset=fill_ipset, apply=apply)
self.blacklist_soft(table=table, fill_ipset=fill_ipset, apply=apply)
self.blacklist_upload(table=table, fill_ipset=fill_ipset, apply=apply)
def raw_table(self):
"""Génère les règles pour la table ``raw`` et remplis les chaines de la table"""
table = 'raw'
chain = 'PREROUTING'
self.add(table, chain, '-d 225.0.0.50 -j DROP')
return
def mangle_table(self):
table = 'mangle'
super(self.__class__, self).mangle_table()
chain = 'PREROUTING'
self.add(table, chain, '-j %s' % self.log_all(table))
self.add(table, chain, '-j %s' % self.connexion_secours(table))
self.add(table, chain, '-p tcp -j CONNMARK --restore-mark')
chain = 'POSTROUTING'
self.add(table, chain, '-j %s' % self.clamp_mss(table))
self.add(table,chain, '-j %s' % self.limitation_debit(table, run_tc=True))
self.add(table, chain, '-j %s' % self.blacklist_upload(table, fill_ipset=True))
return
def filter_table(self):
table = 'filter'
super(self.__class__, self).filter_table()
mac_ip_chain = self.test_mac_ip()
blacklist_hard_chain = self.blacklist_hard()
blacklist_soft_chain = self.blacklist_soft(table, fill_ipset=True)
chain = 'INPUT'
self.flush(table, chain)
self.add(table, chain, '-i lo -j ACCEPT')
self.add(table, chain, '-p icmp -j ACCEPT')
self.add(table, chain, '-m state --state RELATED,ESTABLISHED -j ACCEPT')
self.add(table, chain, '-j %s' % blacklist_soft_chain)
for net in base.config.NETs['all'] + base.config.NETs['adm'] + base.config.NETs['personnel-ens']:
self.add(table, chain, '-s %s -j %s' % (net, mac_ip_chain))
self.add(table, chain, '-j %s' % blacklist_hard_chain)
chain = 'FORWARD'
self.flush(table, chain)
# Valentin veux écouter la radio, en vrai, il faudrait utiliserl'URL authentication de icecast
# (http://www.icecast.org/docs/icecast-2.3.1/icecast2_listenerauth.html)
# pour authoriser les gens logué sur l'intranet2 à écouter la radio de n'importe où
# avec un filtrage par ip (si quelqu'un passe au travers, whos cares
# mais j'ai la flemme
self.add(table, chain, '-p tcp -s 82.227.130.15 -d tv.crans.org --dport 8000 -j ACCEPT') # Valentin veux écouter la radio
self.add(table, chain, '-i lo -j ACCEPT')
self.add(table, chain, '-j %s' % self.reseaux_non_routable(table, fill_ipset=True))
self.add(table, chain, '-p icmp -j ACCEPT')
self.add(table, chain, '-j %s' % self.admin_vlan(table))
self.add(table, chain, '-j %s' % blacklist_soft_chain)
self.add(table, chain, '-i %s -j %s' % (dev['out'], blacklist_hard_chain))
self.add(table, chain, '-o %s -j %s' % (dev['out'], blacklist_hard_chain))
self.add(table, chain, '-m state --state RELATED,ESTABLISHED -j ACCEPT')
self.add(table, chain, '-j %s' % self.tunnel_6in4(table))
for net in base.config.NETs['all'] + base.config.NETs['adm'] + base.config.NETs['personnel-ens']:
self.add(table, chain, '-s %s -j %s' % (net, mac_ip_chain))
self.add(table, chain, '-j %s' % self.connexion_secours(table))
self.add(table, chain, '-j %s' % self.connexion_appartement(table))
self.add(table, chain, '-j %s' % self.ingress_filtering(table))
self.add(table, chain, '-j %s' % self.limit_ssh_connexion(table))
self.add(table, chain, '-i %s -j %s' % (dev['out'], self.filtrage_ports(table)))
self.add(table, chain, '-o %s -j %s' % (dev['out'], self.filtrage_ports(table)))
return
def nat_table(self):
table = 'nat'
super(self.__class__, self).nat_table()
chain = 'PREROUTING'
self.add(table, chain, '-j %s' % self.ssh_on_https(table))
self.add(table, chain, '-j %s' % self.connexion_secours(table))
self.add(table, chain, '-j %s' % self.blacklist_soft(table))
chain = 'POSTROUTING'
self.add(table, chain, '-j %s' % self.connexion_appartement(table))
return
def tunnel_6in4(self, table=None, apply=False):
chain = 'TUNNEL_IPV6'
tunnels_ipv6 = [ ('216.66.84.42', '138.231.136.12'), ('216.66.84.42','138.231.136.164') ]
if table == 'filter':
pretty_print(table, chain)
for sideA, sideB in tunnels_ipv6:
self.add(table, chain, '--proto 41 -s %s -d %s -j ACCEPT' % (sideA, sideB))
self.add(table, chain, '--proto 41 -s %s -d %s -j ACCEPT' % (sideB, sideA))
print OK
if apply:
self.apply(table, chain)
return chain
def limit_ssh_connexion(self, table=None, apply=False):
chain = 'LIMIT-SSH-CONNEXION'
if table == 'filter':
pretty_print(table, chain)
self.add(table, chain, '-i %s -p tcp --dport ssh -m state --state NEW -m recent --name SSH --set' % dev['out'])
self.add(table, chain, '-i %s -p tcp --dport ssh -m state --state NEW -m recent --name SSH --update --seconds 30 --hitcount 10 --rttl -j DROP' % dev['out'])
print OK
if apply:
self.apply(table, chain)
return chain
def test_mac_ip(self, table=None, fill_ipset=False, apply=False):
chain = super(self.__class__, self).test_mac_ip()
if table == 'filter':
for key in ['out', 'tun-ovh' ]:
self.add(table, chain, '-i %s -j RETURN' % dev[key])
return super(self.__class__, self).test_mac_ip(table, fill_ipset, apply)
def log_all(self, table=None, apply=False):
chain = 'LOG_ALL'
if table == 'mangle':
pretty_print(table, chain)
for device in dev.values():
self.add(table, chain, '-i %s -m state --state NEW -j LOG --log-prefix "LOG_ALL "' % device)
print OK
if apply:
self.apply(table, chain)
return chain
def admin_vlan(self, table=None, apply=False):
chain = 'VLAN-ADM'
if table == 'filter':
pretty_print(table, chain)
for net in base.config.NETs['adm']:
self.add(table, chain, '-o %s -s %s -j ACCEPT' % (dev['tun-ovh'], net))
self.add(table, chain, '-i %s -d %s -j ACCEPT' % (dev['tun-ovh'], net))
self.add(table, chain, '-d %s -j REJECT' % net)
print OK
if apply:
self.apply(table, chain)
return chain
def qos(self, table=None, apply=False):
return
def clamp_mss(self, table=None, apply=False):
"""Force la MSS (Max Segment Size) TCP à rentrer dans la MTU (Max Transfert Unit)"""
chain = 'CLAMP-MSS'
if table == 'mangle':
pretty_print(table, chain)
self.add(table, chain, '-p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu')
print OK
if apply:
self.apply(table, chain)
return chain
def ingress_filtering(self, table=None, apply=False):
"""Pour ne pas router les paquêtes n'appartenant pas à notre plage ip voulant sortir de notre réseau
et empêcher certain type de spoof (cf http://travaux.ovh.net/?do=details&id=5183)"""
chain = 'INGRESS_FILTERING'
if table == 'filter':
pretty_print(table, chain)
for net in base.config.NETs['all']:
self.add(table, chain, '-o %s -s %s -j RETURN' % (dev['out'], net))
self.add(table, chain, '-o %s -j LOG --log-prefix BAD_ROUTE' % dev['out'])
self.add(table, chain, '-o %s -j DROP' % dev['out'])
for net_d in base.config.NETs['all']:
for net_s in base.config.NETs['all']:
self.add(table, chain,'-i %s ! -s %s -d %s -j RETURN' % (dev['out'], net_s, net_d))
self.add(table, chain,'-i %s -j LOG --log-prefix BAD_SRC' % dev['out'])
self.add(table, chain,'-i %s -j DROP' % dev['out'])
print OK
if apply:
self.apply(table, chain)
return chain
def ssh_on_https(self, table=None, apply=False):
"""Pour faire fonctionner ssh2.crans.org"""
chain = 'SSH2'
if table == 'nat':
pretty_print(table, chain)
self.add(table, chain, '-p tcp -d 138.231.136.2 --dport 22 -j DNAT --to-destination 138.231.136.1:22') # redirection du ssh vers zamok
self.add(table, chain, '-p tcp -d 138.231.136.2 --dport 443 -j DNAT --to-destination 138.231.136.1:22') # redirection du ssh vers zamok (pour passer dans un proxy, avec corkscrew)
print OK
if apply:
self.apply(table, chain)
return chain
def connexion_secours(self, table=None, apply=False):
"""Redirige les paquets vers un proxy lorsqu'on est en connexion de secours"""
chain = 'CONNEXION-SECOURS'
if table == 'mangle':
pretty_print(table, chain)
self.add(table, chain, '-p tcp -s 138.231.136.0/16 ! -d 138.231.136.0/16 --destination-port 80 -m condition --condition secours -j MARK --set-mark %s' % (base.config.firewall.mark['secours']))
self.add(table, chain, '-m mark --mark %s -j ACCEPT' % base.config.firewall.mark['secours'])
print OK
if table == 'nat':
pretty_print(table, chain)
self.add(table, chain, '-p tcp -m mark --mark %s -j DNAT --to-destination 10.231.136.4:3129' % base.config.firewall.mark['secours'] )
print OK
if table == 'filter':
pretty_print(table, chain)
self.add(table, chain, '-p tcp -s 138.231.136.0/16 ! -d 138.231.136.0/16 --destination-port 443 -m condition --condition secours -j REJECT')
self.add(table, chain, '-m mark --mark %s -j ACCEPT' % base.config.firewall.mark['secours'])
print OK
if apply:
self.apply(table, chain)
return chain
def connexion_appartement(self, table=None, apply=False):
"""PNAT les appartements derrière appartement.crans.org"""
chain = 'CONNEXION-APPARTEMENT'
if table == 'nat':
pretty_print(table, chain)
for dev_key in ['out', 'fil', 'wifi']:
for net in base.config.NETs['personnel-ens']:
self.add(table, chain, '-o %s -s %s -j SNAT --to 138.231.136.44' % (dev[dev_key], net))
print OK
if table == 'filter':
pretty_print(table, chain)
for net in base.config.NETs['personnel-ens']:
self.add(table, chain, '-s %s -j ACCEPT' % net)
self.add(table, chain, '-d %s -j ACCEPT' % net)
print OK
if apply:
self.apply(table, chain)
return chain
def blacklist_soft_maj(self, ip_list):
self.blacklist_soft(fill_ipset=True)
# for ip in ip_list:
# machine = self.conn.search(u"ipHostNumber=%s" % ip)
# # Est-ce qu'il y a des blacklists soft parmis les blacklists de la machine
# if machine and set([bl['type'] for bl in machine[0].blacklist_actif() ]).intersection(base.config.blacklist_sanctions_soft):
# try: self.ipset['blacklist']['soft'].add(ip)
# except IpsetError: pass
# else:
# try: self.ipset['blacklist']['soft'].delete(ip)
# except IpsetError: pass
def blacklist_soft(self, table=None, fill_ipset=False, apply=False):
"""Redirige les gens blacklisté vers le portail captif"""
chain = 'BLACKLIST_SOFT'
if fill_ipset:
# On récupère la liste de toutes les ips blacklistés soft
bl_soft_ips = self.blacklisted_ips(base.config.blacklist_sanctions_soft, base.config.NETs['all'])
anim('\tRestoration de l\'ipset %s' % self.ipset['blacklist']['soft'])
self.ipset['blacklist']['soft'].restore(bl_soft_ips)
print OK
if table == 'filter':
pretty_print(table, chain)
self.add(table, chain, '-p tcp --dport 80 -m set --match-set %s src -j ACCEPT' % self.ipset['blacklist']['soft'] )
self.add(table, chain, '-p tcp --sport 80 -m set --match-set %s dst -j ACCEPT' % self.ipset['blacklist']['soft'] )
self.add(table, chain, '-p tcp -d 10.231.136.4 --dport 3128 -m set --match-set %s src -j ACCEPT' % self.ipset['blacklist']['soft'] )
self.add(table, chain, '-p tcp -s 10.231.136.4 --sport 3128 -m set --match-set %s dst -j ACCEPT' % self.ipset['blacklist']['soft'] )
print OK
if table == 'nat':
pretty_print(table, chain)
for net in base.config.NETs['all']:
self.add(table, chain, '-d %s -j RETURN' % net)
self.add(table, chain, '-p tcp --dport 80 -m set --match-set %s src -j DNAT --to-destination 10.231.136.4:3128' % self.ipset['blacklist']['soft'] )
print OK
if apply:
self.apply(table, chain)
return chain
def blacklist_upload_maj(self, ip_list):
self.blacklist_upload(fill_ipset=True)
# for ip in ip_list:
# machine = self.conn.search(u"ipHostNumber=%s" % ip)
# # Est-ce qu'il y a des blacklists pour upload parmis les blacklists de la machine
# if machine and set([bl['type'] for bl in machine[0].blacklist_actif() ]).intersection(blacklist_bridage_upload):
# try: self.ipset['blacklist']['upload'].add(ip)
# except IpsetError: pass
# else:
# try: self.ipset['blacklist']['upload'].delete(ip)
# except IpsetError: pass
def blacklist_upload(self, table=None, fill_ipset=False, apply=False):
"""Les gens blacklistés ne sont plus prioritaires (classe de qos commune)"""
chain = 'BLACKLIST_UPLOAD'
if fill_ipset:
# On récupère la liste de toutes les ips blacklistés pour upload
bl_upload_ips = self.blacklisted_ips(base.config.blacklist_bridage_upload, base.config.NETs['all'])
anim('\tRestoration de l\'ipset %s' % self.ipset['blacklist']['upload'])
self.ipset['blacklist']['upload'].restore(bl_upload_ips)
print OK
if table == 'mangle':
pretty_print(table, chain)
# Classification pour les blacklists upload
self.add(table, chain, '-o %s -m set --match-set %s src -j CLASSIFY --set-class 1:11' % (dev['out'], self.ipset['blacklist']['upload']))
print OK
if apply:
self.apply(table, chain)
return chain
def reseaux_non_routable(self, table=None, fill_ipset=False, apply=False):
"""Bloque les réseaux non routables autres que ceux utilisés par le crans"""
chain = 'RESEAUX_NON_ROUTABLES'
if fill_ipset:
anim('\tRestoration de l\'ipset reseaux_non_routable')
allowed = [ net for nets in base.config.NETs.values() for net in nets if utils.NetInNets(net, base.config.firewall.reseaux_non_routables) ]
self.ipset['reseaux_non_routable']['allow'].restore(allowed)
self.ipset['reseaux_non_routable']['deny'].restore(base.config.firewall.reseaux_non_routables)
print OK
if table == 'filter':
pretty_print(table, chain)
self.add(table, chain, '-m set --match-set %s src -j RETURN' % self.ipset['reseaux_non_routable']['allow'])
self.add(table, chain, '-m set --match-set %s dst -j RETURN' % self.ipset['reseaux_non_routable']['allow'])
self.add(table, chain, '-m set --match-set %s src -j DROP' % self.ipset['reseaux_non_routable']['deny'])
self.add(table, chain, '-m set --match-set %s dst -j DROP' % self.ipset['reseaux_non_routable']['deny'])
print OK
if apply:
self.apply(table, chain)
return chain
def filtrage_ports_maj(self, ip_lists):
self.filtrage_ports('filter', apply=True)
def filtrage_ports(self, table=None, apply=False):
"""Ouvre les ports vers et depuis les machines du réseau crans"""
chain = 'FILTRAGE-PORTS'
def format_port(port):
port = str(port)
if port.endswith(':'):
port = '%s65535' % port
if port.startswith(':'):
port = '0%s' % port
return port
def add_ports(ip, machine, proto, sens):
self.add(
table,
chain,
'-p %s -%s %s -m multiport --dports %s -j RETURN' % (
proto,
(sens=='out' and 's') or (sens == 'in' and 'd'),
ip,
','.join( format_port(port) for port in machine['port%s%s' % (proto.upper(), sens)])
)
)
if table == 'filter':
pretty_print(table, chain)
for net in base.config.NETs['serveurs']:
for proto in base.config.firewall.srv_ports_default.keys():
if base.config.firewall.srv_ports_default[proto]['output']:
self.add(table, chain, '-p %s -s %s -m multiport --dports %s -j RETURN' % (proto, net, ','.join( format_port(port) for port in base.config.firewall.ports_default[proto]['output'])))
if base.config.firewall.srv_ports_default[proto]['input']:
self.add(table, chain, '-p %s -d %s -m multiport --dports %s -j RETURN' % (proto, net, ','.join( format_port(port) for port in base.config.firewall.ports_default[proto]['input'])))
for net in base.config.NETs['adherents'] + base.config.NETs['wifi-adh'] + base.config.NETs['personnel-ens']:
for proto in base.config.firewall.ports_default.keys():
if base.config.firewall.ports_default[proto]['output']:
self.add(table, chain, '-p %s -s %s -m multiport --dports %s -j RETURN' % (proto, net, ','.join( format_port(port) for port in base.config.firewall.ports_default[proto]['output'])))
if base.config.firewall.ports_default[proto]['input']:
self.add(table, chain, '-p %s -d %s -m multiport --dports %s -j RETURN' % (proto, net, ','.join( format_port(port) for port in base.config.firewall.ports_default[proto]['input'])))
for machine in self.machines():
for ip in machine['ipHostNumber']:
if 'portTCPout' in machine:
add_ports(ip, machine, 'tcp', 'out')
if 'portUDPout' in machine:
add_ports(ip, machine, 'udp', 'out')
if 'portTCPin' in machine:
add_ports(ip, machine, 'tcp', 'in')
if 'portUDPin' in machine:
add_ports(ip, machine, 'udp', 'in')
self.add(table, chain, '-j REJECT')
print OK
if apply:
self.apply(table, chain)
return chain
def limitation_debit(self, table=None, run_tc=False, apply=False):
"""Limite le débit de la connexion selon l'agréement avec l'ENS"""
chain = 'LIMITATION-DEBIT'
debit_max = base.config.firewall.debit_max
uplink_speed = '1024mbit'
if table == 'mangle':
pretty_print(table, chain)
# Pas de QoS vers/depuis la zone ENS
self.add(table, chain, '-d 138.231.0.0/16 -s 138.231.0.0/16 -j RETURN')
# Idem pour le ftp
self.add(table, chain, '-d ftp.crans.org -j RETURN')
self.add(table, chain, '-s ftp.crans.org -j RETURN')
self.add(table, chain, '-d tv.crans.org -j RETURN')
self.add(table, chain, '-s tv.crans.org -j RETURN')
# Idem vers soyouz pour le test de la connection de secours
self.add(table, chain, '-d soyouz.crans.org -j RETURN')
self.add(table, chain, '-s soyouz.crans.org -j RETURN')
# Classification par defaut pour tous les paquets
for net in base.config.NETs['all']:
self.add(table, chain, '-o %s -s %s -j CLASSIFY --set-class 1:10' % (dev['out'], net))
self.add(table, chain, '-o %s -d %s -j CLASSIFY --set-class 1:10' % (dev['fil'], net))
self.add(table, chain, '-o %s -d %s -j CLASSIFY --set-class 1:10' % (dev['wifi'], net))
# Classification pour les appartements
for net in base.config.NETs['personnel-ens']:
self.add(table, chain, '-o %s -d %s -j CLASSIFY --set-class 1:3' % (dev['app'], net))
self.add(table, chain, '-o %s -s %s -j CLASSIFY --set-class 1:2' % (dev['out'], net))
# Classification pour la voip
self.add(table, chain, '-d sip.crans.org -j CLASSIFY --set-class 1:12')
self.add(table, chain, '-s sip.crans.org -j CLASSIFY --set-class 1:12')
print OK
if run_tc:
anim('\tApplication des commandes tc')
for int_key in ['out', 'fil', 'wifi']:
try:
utils.tc('qdisc del dev %s root' % dev[int_key])
except utils.TcError:
pass
utils.tc('qdisc add dev %s root handle 1: htb r2q 1' % dev[int_key])
utils.tc("class add dev %s parent 1: classid 1:1 "
"htb rate %s ceil %s" % (dev[int_key], uplink_speed, uplink_speed))
utils.tc("class add dev %s parent 1:1 classid 1:2 "
"htb rate %skbps ceil %skbps" % (dev[int_key], debit_max, debit_max))
# Classe par defaut
utils.tc('class add dev %s parent 1:2 classid 1:10 '
'htb rate %skbps ceil %skbps prio 1' % (dev[int_key], debit_max, debit_max))
utils.tc('qdisc add dev %s parent 1:10 '
'handle 10: sfq perturb 10' % dev[int_key])
# Classe par pour la voip
utils.tc('class add dev %s parent 1:2 classid 1:12 '
'htb rate %skbps ceil %skbps prio 0' % (dev[int_key], debit_max, debit_max))
utils.tc('qdisc add dev %s parent 1:12 '
'handle 12: sfq perturb 10' % dev[int_key])
#Classe des decos upload
utils.tc('class add dev %s parent 1:2 classid 1:11 '
'htb rate 60kbps ceil 60kbps prio 1' % dev['out'])
utils.tc('qdisc add dev %s parent 1:11 '
'handle 11: sfq perturb 10' % dev['out'])
for int_key in ['app']:
try:
utils.tc('qdisc del dev %s root' % dev[int_key])
except TcError:
pass
utils.tc('qdisc add dev %s root handle 1: htb r2q 1' % dev[int_key])
utils.tc("class add dev %s parent 1: classid 1:1 "
"htb rate 128kbps ceil 128kbps" % dev[int_key])
# Classe pour l'upload des appartements
utils.tc("class add dev %s parent 1:1 classid 1:2 "
"htb rate 128kbps ceil 128kbps" % dev[int_key])
utils.tc('qdisc add dev %s parent 1:2 '
'handle 2: sfq perturb 10' % dev[int_key])
# Classe pour le download des apparetments
utils.tc("class add dev %s parent 1: classid 1:3 "
"htb rate %skbps ceil %skbps" % (dev[int_key], debit_max/10, debit_max/2))
utils.tc('qdisc add dev %s parent 1:3 '
'handle 3: sfq perturb 10' % dev[int_key])
print OK
if apply:
self.apply(table, chain)
return chain