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mirror of https://github.com/mailcow/mailcow-dockerized.git synced 2024-11-30 08:59:40 +02:00

[Netfilter] add nftables support

This commit is contained in:
FreddleSpl0it 2023-10-30 11:54:14 +01:00
parent a366494c34
commit f39005b72d
No known key found for this signature in database
GPG Key ID: 00E14E7634F4BEC5
8 changed files with 1232 additions and 3 deletions

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@ -1,6 +1,8 @@
FROM alpine:3.17
LABEL maintainer "The Infrastructure Company GmbH <info@servercow.de>"
WORKDIR /app
ENV XTABLES_LIBDIR /usr/lib/xtables
ENV PYTHON_IPTABLES_XTABLES_VERSION 12
ENV IPTABLES_LIBDIR /usr/lib
@ -14,10 +16,13 @@ RUN apk add --virtual .build-deps \
iptables \
ip6tables \
xtables-addons \
nftables \
tzdata \
py3-pip \
py3-nftables \
musl-dev \
&& pip3 install --ignore-installed --upgrade pip \
jsonschema \
python-iptables \
redis \
ipaddress \
@ -26,5 +31,10 @@ RUN apk add --virtual .build-deps \
# && pip3 install --upgrade pip python-iptables==0.13.0 redis ipaddress dnspython \
COPY server.py /
CMD ["python3", "-u", "/server.py"]
COPY modules /app/modules
COPY main.py /app/
COPY ./docker-entrypoint.sh /app/
RUN chmod +x /app/docker-entrypoint.sh
CMD ["/bin/sh", "-c", "/app/docker-entrypoint.sh"]

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@ -0,0 +1,29 @@
#!/bin/sh
backend=iptables
nft list table ip filter &>/dev/null
nftables_found=$?
iptables -L -n &>/dev/null
iptables_found=$?
if [ $nftables_found -lt $iptables_found ]; then
backend=nftables
fi
if [ $nftables_found -gt $iptables_found ]; then
backend=iptables
fi
if [ $nftables_found -eq 0 ] && [ $nftables_found -eq $iptables_found ]; then
nftables_lines=$(nft list ruleset | wc -l)
iptables_lines=$(iptables-save | wc -l)
if [ $nftables_lines -gt $iptables_lines ]; then
backend=nftables
else
backend=iptables
fi
fi
exec python -u /app/main.py $backend

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@ -0,0 +1,459 @@
#!/usr/bin/env python3
import re
import os
import sys
import time
import atexit
import signal
import ipaddress
from collections import Counter
from random import randint
from threading import Thread
from threading import Lock
import redis
import json
import dns.resolver
import dns.exception
from modules.Logger import Logger
from modules.IPTables import IPTables
from modules.NFTables import NFTables
# connect to redis
while True:
try:
redis_slaveof_ip = os.getenv('REDIS_SLAVEOF_IP', '')
redis_slaveof_port = os.getenv('REDIS_SLAVEOF_PORT', '')
if "".__eq__(redis_slaveof_ip):
r = redis.StrictRedis(host=os.getenv('IPV4_NETWORK', '172.22.1') + '.249', decode_responses=True, port=6379, db=0)
else:
r = redis.StrictRedis(host=redis_slaveof_ip, decode_responses=True, port=redis_slaveof_port, db=0)
r.ping()
except Exception as ex:
print('%s - trying again in 3 seconds' % (ex))
time.sleep(3)
else:
break
pubsub = r.pubsub()
# rename fail2ban to netfilter
if r.exists('F2B_LOG'):
r.rename('F2B_LOG', 'NETFILTER_LOG')
# globals
WHITELIST = []
BLACKLIST= []
bans = {}
quit_now = False
exit_code = 0
lock = Lock()
# init Logger
logger = Logger(r)
# init backend
backend = sys.argv[1]
if backend == "nftables":
logger.logInfo('Using NFTables backend')
tables = NFTables("MAILCOW", logger)
else:
logger.logInfo('Using IPTables backend')
tables = IPTables("MAILCOW", logger)
def refreshF2boptions():
global f2boptions
global quit_now
global exit_code
f2boptions = {}
if not r.get('F2B_OPTIONS'):
f2boptions['ban_time'] = r.get('F2B_BAN_TIME')
f2boptions['max_ban_time'] = r.get('F2B_MAX_BAN_TIME')
f2boptions['ban_time_increment'] = r.get('F2B_BAN_TIME_INCREMENT')
f2boptions['max_attempts'] = r.get('F2B_MAX_ATTEMPTS')
f2boptions['retry_window'] = r.get('F2B_RETRY_WINDOW')
f2boptions['netban_ipv4'] = r.get('F2B_NETBAN_IPV4')
f2boptions['netban_ipv6'] = r.get('F2B_NETBAN_IPV6')
else:
try:
f2boptions = json.loads(r.get('F2B_OPTIONS'))
except ValueError:
logger.logCrit('Error loading F2B options: F2B_OPTIONS is not json')
quit_now = True
exit_code = 2
verifyF2boptions(f2boptions)
r.set('F2B_OPTIONS', json.dumps(f2boptions, ensure_ascii=False))
def verifyF2boptions(f2boptions):
verifyF2boption(f2boptions,'ban_time', 1800)
verifyF2boption(f2boptions,'max_ban_time', 10000)
verifyF2boption(f2boptions,'ban_time_increment', True)
verifyF2boption(f2boptions,'max_attempts', 10)
verifyF2boption(f2boptions,'retry_window', 600)
verifyF2boption(f2boptions,'netban_ipv4', 32)
verifyF2boption(f2boptions,'netban_ipv6', 128)
def verifyF2boption(f2boptions, f2boption, f2bdefault):
f2boptions[f2boption] = f2boptions[f2boption] if f2boption in f2boptions and f2boptions[f2boption] is not None else f2bdefault
def refreshF2bregex():
global f2bregex
global quit_now
global exit_code
if not r.get('F2B_REGEX'):
f2bregex = {}
f2bregex[1] = 'mailcow UI: Invalid password for .+ by ([0-9a-f\.:]+)'
f2bregex[2] = 'Rspamd UI: Invalid password by ([0-9a-f\.:]+)'
f2bregex[3] = 'warning: .*\[([0-9a-f\.:]+)\]: SASL .+ authentication failed: (?!.*Connection lost to authentication server).+'
f2bregex[4] = 'warning: non-SMTP command from .*\[([0-9a-f\.:]+)]:.+'
f2bregex[5] = 'NOQUEUE: reject: RCPT from \[([0-9a-f\.:]+)].+Protocol error.+'
f2bregex[6] = '-login: Disconnected.+ \(auth failed, .+\): user=.*, method=.+, rip=([0-9a-f\.:]+),'
f2bregex[7] = '-login: Aborted login.+ \(auth failed .+\): user=.+, rip=([0-9a-f\.:]+), lip.+'
f2bregex[8] = '-login: Aborted login.+ \(tried to use disallowed .+\): user=.+, rip=([0-9a-f\.:]+), lip.+'
f2bregex[9] = 'SOGo.+ Login from \'([0-9a-f\.:]+)\' for user .+ might not have worked'
f2bregex[10] = '([0-9a-f\.:]+) \"GET \/SOGo\/.* HTTP.+\" 403 .+'
r.set('F2B_REGEX', json.dumps(f2bregex, ensure_ascii=False))
else:
try:
f2bregex = {}
f2bregex = json.loads(r.get('F2B_REGEX'))
except ValueError:
logger.logCrit('Error loading F2B options: F2B_REGEX is not json')
quit_now = True
exit_code = 2
def get_ip(address):
ip = ipaddress.ip_address(address)
if type(ip) is ipaddress.IPv6Address and ip.ipv4_mapped:
ip = ip.ipv4_mapped
if ip.is_private or ip.is_loopback:
return False
return ip
def ban(address):
global lock
refreshF2boptions()
BAN_TIME = int(f2boptions['ban_time'])
BAN_TIME_INCREMENT = bool(f2boptions['ban_time_increment'])
MAX_ATTEMPTS = int(f2boptions['max_attempts'])
RETRY_WINDOW = int(f2boptions['retry_window'])
NETBAN_IPV4 = '/' + str(f2boptions['netban_ipv4'])
NETBAN_IPV6 = '/' + str(f2boptions['netban_ipv6'])
ip = get_ip(address)
if not ip: return
address = str(ip)
self_network = ipaddress.ip_network(address)
with lock:
temp_whitelist = set(WHITELIST)
if temp_whitelist:
for wl_key in temp_whitelist:
wl_net = ipaddress.ip_network(wl_key, False)
if wl_net.overlaps(self_network):
logger.logInfo('Address %s is whitelisted by rule %s' % (self_network, wl_net))
return
net = ipaddress.ip_network((address + (NETBAN_IPV4 if type(ip) is ipaddress.IPv4Address else NETBAN_IPV6)), strict=False)
net = str(net)
if not net in bans:
bans[net] = {'attempts': 0, 'last_attempt': 0, 'ban_counter': 0}
bans[net]['attempts'] += 1
bans[net]['last_attempt'] = time.time()
if bans[net]['attempts'] >= MAX_ATTEMPTS:
cur_time = int(round(time.time()))
NET_BAN_TIME = BAN_TIME if not BAN_TIME_INCREMENT else BAN_TIME * 2 ** bans[net]['ban_counter']
logger.logCrit('Banning %s for %d minutes' % (net, NET_BAN_TIME / 60 ))
if type(ip) is ipaddress.IPv4Address:
with lock:
tables.banIPv4(net)
else:
with lock:
tables.banIPv6(net)
r.hset('F2B_ACTIVE_BANS', '%s' % net, cur_time + NET_BAN_TIME)
else:
logger.logWarn('%d more attempts in the next %d seconds until %s is banned' % (MAX_ATTEMPTS - bans[net]['attempts'], RETRY_WINDOW, net))
def unban(net):
global lock
if not net in bans:
logger.logInfo('%s is not banned, skipping unban and deleting from queue (if any)' % net)
r.hdel('F2B_QUEUE_UNBAN', '%s' % net)
return
logger.logInfo('Unbanning %s' % net)
if type(ipaddress.ip_network(net)) is ipaddress.IPv4Network:
with lock:
tables.unbanIPv4(net)
else:
with lock:
tables.unbanIPv6(net)
r.hdel('F2B_ACTIVE_BANS', '%s' % net)
r.hdel('F2B_QUEUE_UNBAN', '%s' % net)
if net in bans:
bans[net]['attempts'] = 0
bans[net]['ban_counter'] += 1
def permBan(net, unban=False):
global lock
is_unbanned = False
is_banned = False
if type(ipaddress.ip_network(net, strict=False)) is ipaddress.IPv4Network:
with lock:
if unban:
is_unbanned = tables.unbanIPv4(net)
else:
is_banned = tables.banIPv4(net)
else:
with lock:
if unban:
is_unbanned = tables.unbanIPv6(net)
else:
is_banned = tables.banIPv6(net)
if is_unbanned:
r.hdel('F2B_PERM_BANS', '%s' % net)
logger.logCrit('Removed host/network %s from blacklist' % net)
elif is_banned:
r.hset('F2B_PERM_BANS', '%s' % net, int(round(time.time())))
logger.logCrit('Added host/network %s to blacklist' % net)
def clear():
global lock
logger.logInfo('Clearing all bans')
for net in bans.copy():
unban(net)
with lock:
tables.clearIPv4Table()
tables.clearIPv6Table()
r.delete('F2B_ACTIVE_BANS')
r.delete('F2B_PERM_BANS')
pubsub.unsubscribe()
def watch():
logger.logInfo('Watching Redis channel F2B_CHANNEL')
pubsub.subscribe('F2B_CHANNEL')
global quit_now
global exit_code
while not quit_now:
try:
for item in pubsub.listen():
refreshF2bregex()
for rule_id, rule_regex in f2bregex.items():
if item['data'] and item['type'] == 'message':
try:
result = re.search(rule_regex, item['data'])
except re.error:
result = False
if result:
addr = result.group(1)
ip = ipaddress.ip_address(addr)
if ip.is_private or ip.is_loopback:
continue
logger.logWarn('%s matched rule id %s (%s)' % (addr, rule_id, item['data']))
ban(addr)
except Exception as ex:
logger.logWarn('Error reading log line from pubsub: %s' % ex)
quit_now = True
exit_code = 2
def snat4(snat_target):
global lock
global quit_now
while not quit_now:
time.sleep(10)
with lock:
tables.snat4(snat_target, os.getenv('IPV4_NETWORK', '172.22.1') + '.0/24')
def snat6(snat_target):
global lock
global quit_now
while not quit_now:
time.sleep(10)
with lock:
tables.snat6(snat_target, os.getenv('IPV6_NETWORK', 'fd4d:6169:6c63:6f77::/64'))
def autopurge():
while not quit_now:
time.sleep(10)
refreshF2boptions()
BAN_TIME = int(f2boptions['ban_time'])
MAX_BAN_TIME = int(f2boptions['max_ban_time'])
BAN_TIME_INCREMENT = bool(f2boptions['ban_time_increment'])
MAX_ATTEMPTS = int(f2boptions['max_attempts'])
QUEUE_UNBAN = r.hgetall('F2B_QUEUE_UNBAN')
if QUEUE_UNBAN:
for net in QUEUE_UNBAN:
unban(str(net))
for net in bans.copy():
if bans[net]['attempts'] >= MAX_ATTEMPTS:
NET_BAN_TIME = BAN_TIME if not BAN_TIME_INCREMENT else BAN_TIME * 2 ** bans[net]['ban_counter']
TIME_SINCE_LAST_ATTEMPT = time.time() - bans[net]['last_attempt']
if TIME_SINCE_LAST_ATTEMPT > NET_BAN_TIME or TIME_SINCE_LAST_ATTEMPT > MAX_BAN_TIME:
unban(net)
def mailcowChainOrder():
global lock
global quit_now
global exit_code
while not quit_now:
time.sleep(10)
with lock:
quit_now, exit_code = tables.checkIPv4ChainOrder()
if quit_now: return
quit_now, exit_code = tables.checkIPv6ChainOrder()
def isIpNetwork(address):
try:
ipaddress.ip_network(address, False)
except ValueError:
return False
return True
def genNetworkList(list):
resolver = dns.resolver.Resolver()
hostnames = []
networks = []
for key in list:
if isIpNetwork(key):
networks.append(key)
else:
hostnames.append(key)
for hostname in hostnames:
hostname_ips = []
for rdtype in ['A', 'AAAA']:
try:
answer = resolver.resolve(qname=hostname, rdtype=rdtype, lifetime=3)
except dns.exception.Timeout:
logger.logInfo('Hostname %s timedout on resolve' % hostname)
break
except (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer):
continue
except dns.exception.DNSException as dnsexception:
logger.logInfo('%s' % dnsexception)
continue
for rdata in answer:
hostname_ips.append(rdata.to_text())
networks.extend(hostname_ips)
return set(networks)
def whitelistUpdate():
global lock
global quit_now
global WHITELIST
while not quit_now:
start_time = time.time()
list = r.hgetall('F2B_WHITELIST')
new_whitelist = []
if list:
new_whitelist = genNetworkList(list)
with lock:
if Counter(new_whitelist) != Counter(WHITELIST):
WHITELIST = new_whitelist
logger.logInfo('Whitelist was changed, it has %s entries' % len(WHITELIST))
time.sleep(60.0 - ((time.time() - start_time) % 60.0))
def blacklistUpdate():
global quit_now
global BLACKLIST
while not quit_now:
start_time = time.time()
list = r.hgetall('F2B_BLACKLIST')
new_blacklist = []
if list:
new_blacklist = genNetworkList(list)
if Counter(new_blacklist) != Counter(BLACKLIST):
addban = set(new_blacklist).difference(BLACKLIST)
delban = set(BLACKLIST).difference(new_blacklist)
BLACKLIST = new_blacklist
logger.logInfo('Blacklist was changed, it has %s entries' % len(BLACKLIST))
if addban:
for net in addban:
permBan(net=net)
if delban:
for net in delban:
permBan(net=net, unban=True)
time.sleep(60.0 - ((time.time() - start_time) % 60.0))
def quit(signum, frame):
global quit_now
quit_now = True
if __name__ == '__main__':
# In case a previous session was killed without cleanup
clear()
# Reinit MAILCOW chain
# Is called before threads start, no locking
logger.logInfo("Initializing mailcow netfilter chain")
tables.initChainIPv4()
tables.initChainIPv6()
watch_thread = Thread(target=watch)
watch_thread.daemon = True
watch_thread.start()
if os.getenv('SNAT_TO_SOURCE') and os.getenv('SNAT_TO_SOURCE') != 'n':
try:
snat_ip = os.getenv('SNAT_TO_SOURCE')
snat_ipo = ipaddress.ip_address(snat_ip)
if type(snat_ipo) is ipaddress.IPv4Address:
snat4_thread = Thread(target=snat4,args=(snat_ip,))
snat4_thread.daemon = True
snat4_thread.start()
except ValueError:
print(os.getenv('SNAT_TO_SOURCE') + ' is not a valid IPv4 address')
if os.getenv('SNAT6_TO_SOURCE') and os.getenv('SNAT6_TO_SOURCE') != 'n':
try:
snat_ip = os.getenv('SNAT6_TO_SOURCE')
snat_ipo = ipaddress.ip_address(snat_ip)
if type(snat_ipo) is ipaddress.IPv6Address:
snat6_thread = Thread(target=snat6,args=(snat_ip,))
snat6_thread.daemon = True
snat6_thread.start()
except ValueError:
print(os.getenv('SNAT6_TO_SOURCE') + ' is not a valid IPv6 address')
autopurge_thread = Thread(target=autopurge)
autopurge_thread.daemon = True
autopurge_thread.start()
mailcowchainwatch_thread = Thread(target=mailcowChainOrder)
mailcowchainwatch_thread.daemon = True
mailcowchainwatch_thread.start()
blacklistupdate_thread = Thread(target=blacklistUpdate)
blacklistupdate_thread.daemon = True
blacklistupdate_thread.start()
whitelistupdate_thread = Thread(target=whitelistUpdate)
whitelistupdate_thread.daemon = True
whitelistupdate_thread.start()
signal.signal(signal.SIGTERM, quit)
atexit.register(clear)
while not quit_now:
time.sleep(0.5)
sys.exit(exit_code)

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@ -0,0 +1,213 @@
import iptc
import time
class IPTables:
def __init__(self, chain_name, logger):
self.chain_name = chain_name
self.logger = logger
def initChainIPv4(self):
if not iptc.Chain(iptc.Table(iptc.Table.FILTER), self.chain_name) in iptc.Table(iptc.Table.FILTER).chains:
iptc.Table(iptc.Table.FILTER).create_chain(self.chain_name)
for c in ['FORWARD', 'INPUT']:
chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), c)
rule = iptc.Rule()
rule.src = '0.0.0.0/0'
rule.dst = '0.0.0.0/0'
target = iptc.Target(rule, self.chain_name)
rule.target = target
if rule not in chain.rules:
chain.insert_rule(rule)
def initChainIPv6(self):
if not iptc.Chain(iptc.Table6(iptc.Table6.FILTER), self.chain_name) in iptc.Table6(iptc.Table6.FILTER).chains:
iptc.Table6(iptc.Table6.FILTER).create_chain(self.chain_name)
for c in ['FORWARD', 'INPUT']:
chain = iptc.Chain(iptc.Table6(iptc.Table6.FILTER), c)
rule = iptc.Rule6()
rule.src = '::/0'
rule.dst = '::/0'
target = iptc.Target(rule, self.chain_name)
rule.target = target
if rule not in chain.rules:
chain.insert_rule(rule)
def checkIPv4ChainOrder(self):
filter_table = iptc.Table(iptc.Table.FILTER)
filter_table.refresh()
return self.checkChainOrder(filter_table)
def checkIPv6ChainOrder(self):
filter_table = iptc.Table6(iptc.Table6.FILTER)
filter_table.refresh()
return self.checkChainOrder(filter_table)
def checkChainOrder(self, filter_table):
err = False
exit_code = None
forward_chain = iptc.Chain(filter_table, 'FORWARD')
input_chain = iptc.Chain(filter_table, 'INPUT')
for chain in [forward_chain, input_chain]:
target_found = False
for position, item in enumerate(chain.rules):
if item.target.name == self.chain_name:
target_found = True
if position > 2:
self.logger.logCrit('Error in %s chain: %s target not found, restarting container' % (chain.name, self.chain_name))
err = True
exit_code = 2
if not target_found:
self.logger.logCrit('Error in %s chain: %s target not found, restarting container' % (chain.name, self.chain_name))
err = True
exit_code = 2
return err, exit_code
def clearIPv4Table(self):
self.clearTable(iptc.Table(iptc.Table.FILTER))
def clearIPv6Table(self):
self.clearTable(iptc.Table6(iptc.Table6.FILTER))
def clearTable(self, filter_table):
filter_table.autocommit = False
forward_chain = iptc.Chain(filter_table, "FORWARD")
input_chain = iptc.Chain(filter_table, "INPUT")
mailcow_chain = iptc.Chain(filter_table, self.chain_name)
if mailcow_chain in filter_table.chains:
for rule in mailcow_chain.rules:
mailcow_chain.delete_rule(rule)
for rule in forward_chain.rules:
if rule.target.name == self.chain_name:
forward_chain.delete_rule(rule)
for rule in input_chain.rules:
if rule.target.name == self.chain_name:
input_chain.delete_rule(rule)
filter_table.delete_chain(self.chain_name)
filter_table.commit()
filter_table.refresh()
filter_table.autocommit = True
def banIPv4(self, source):
chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), self.chain_name)
rule = iptc.Rule()
rule.src = source
target = iptc.Target(rule, "REJECT")
rule.target = target
if rule in chain.rules:
return False
chain.insert_rule(rule)
return True
def banIPv6(self, source):
chain = iptc.Chain(iptc.Table6(iptc.Table6.FILTER), self.chain_name)
rule = iptc.Rule6()
rule.src = source
target = iptc.Target(rule, "REJECT")
rule.target = target
if rule in chain.rules:
return False
chain.insert_rule(rule)
return True
def unbanIPv4(self, source):
chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), self.chain_name)
rule = iptc.Rule()
rule.src = source
target = iptc.Target(rule, "REJECT")
rule.target = target
if rule not in chain.rules:
return False
chain.delete_rule(rule)
return True
def unbanIPv6(self, source):
chain = iptc.Chain(iptc.Table6(iptc.Table6.FILTER), self.chain_name)
rule = iptc.Rule6()
rule.src = source
target = iptc.Target(rule, "REJECT")
rule.target = target
if rule not in chain.rules:
return False
chain.delete_rule(rule)
return True
def snat4(self, snat_target, source):
try:
table = iptc.Table('nat')
table.refresh()
chain = iptc.Chain(table, 'POSTROUTING')
table.autocommit = False
new_rule = self.getSnat4Rule(snat_target, source)
if not chain.rules:
# if there are no rules in the chain, insert the new rule directly
self.logger.logInfo(f'Added POSTROUTING rule for source network {new_rule.src} to SNAT target {snat_target}')
chain.insert_rule(new_rule)
else:
for position, rule in enumerate(chain.rules):
if not hasattr(rule.target, 'parameter'):
continue
match = all((
new_rule.get_src() == rule.get_src(),
new_rule.get_dst() == rule.get_dst(),
new_rule.target.parameters == rule.target.parameters,
new_rule.target.name == rule.target.name
))
if position == 0:
if not match:
self.logger.logInfo(f'Added POSTROUTING rule for source network {new_rule.src} to SNAT target {snat_target}')
chain.insert_rule(new_rule)
else:
if match:
self.logger.logInfo(f'Remove rule for source network {new_rule.src} to SNAT target {snat_target} from POSTROUTING chain at position {position}')
chain.delete_rule(rule)
table.commit()
table.autocommit = True
return True
except:
self.logger.logCrit('Error running SNAT4, retrying...')
return False
def snat6(self, snat_target, source):
try:
table = iptc.Table6('nat')
table.refresh()
chain = iptc.Chain(table, 'POSTROUTING')
table.autocommit = False
new_rule = self.getSnat6Rule(snat_target, source)
if new_rule not in chain.rules:
self.logger.logInfo('Added POSTROUTING rule for source network %s to SNAT target %s' % (new_rule.src, snat_target))
chain.insert_rule(new_rule)
else:
for position, item in enumerate(chain.rules):
if item == new_rule:
if position != 0:
chain.delete_rule(new_rule)
table.commit()
table.autocommit = True
except:
self.logger.logCrit('Error running SNAT6, retrying...')
def getSnat4Rule(self, snat_target, source):
rule = iptc.Rule()
rule.src = source
rule.dst = '!' + rule.src
target = rule.create_target("SNAT")
target.to_source = snat_target
match = rule.create_match("comment")
match.comment = f'{int(round(time.time()))}'
return rule
def getSnat6Rule(self, snat_target, source):
rule = iptc.Rule6()
rule.src = source
rule.dst = '!' + rule.src
target = rule.create_target("SNAT")
target.to_source = snat_target
return rule

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@ -0,0 +1,23 @@
import time
import json
class Logger:
def __init__(self, redis):
self.r = redis
def log(self, priority, message):
tolog = {}
tolog['time'] = int(round(time.time()))
tolog['priority'] = priority
tolog['message'] = message
self.r.lpush('NETFILTER_LOG', json.dumps(tolog, ensure_ascii=False))
print(message)
def logWarn(self, message):
self.log('warn', message)
def logCrit(self, message):
self.log('crit', message)
def logInfo(self, message):
self.log('info', message)

View File

@ -0,0 +1,495 @@
import nftables
import ipaddress
class NFTables:
def __init__(self, chain_name, logger):
self.chain_name = chain_name
self.logger = logger
self.nft = nftables.Nftables()
self.nft.set_json_output(True)
self.nft.set_handle_output(True)
self.nft_chain_names = {'ip': {'filter': {'input': '', 'forward': ''}, 'nat': {'postrouting': ''} },
'ip6': {'filter': {'input': '', 'forward': ''}, 'nat': {'postrouting': ''} } }
self.search_current_chains()
def initChainIPv4(self):
self.insert_mailcow_chains("ip")
def initChainIPv6(self):
self.insert_mailcow_chains("ip6")
def checkIPv4ChainOrder(self):
return self.checkChainOrder("ip")
def checkIPv6ChainOrder(self):
return self.checkChainOrder("ip6")
def checkChainOrder(self, filter_table):
err = False
exit_code = None
for chain in ['input', 'forward']:
chain_position = self.check_mailcow_chains(filter_table, chain)
if chain_position is None: continue
if chain_position is False:
self.logger.logCrit(f'MAILCOW target not found in {filter_table} {chain} table, restarting container to fix it...')
err = True
exit_code = 2
if chain_position > 0:
self.logger.logCrit(f'MAILCOW target is in position {chain_position} in the {filter_table} {chain} table, restarting container to fix it...')
err = True
exit_code = 2
return err, exit_code
def clearIPv4Table(self):
self.clearTable("ip")
def clearIPv6Table(self):
self.clearTable("ip6")
def clearTable(self, _family):
is_empty_dict = True
json_command = self.get_base_dict()
chain_handle = self.get_chain_handle(_family, "filter", self.chain_name)
# if no handle, the chain doesn't exists
if chain_handle is not None:
is_empty_dict = False
# flush chain
mailcow_chain = {'family': _family, 'table': 'filter', 'name': self.chain_name}
flush_chain = {'flush': {'chain': mailcow_chain}}
json_command["nftables"].append(flush_chain)
# remove rule in forward chain
# remove rule in input chain
chains_family = [self.nft_chain_names[_family]['filter']['input'],
self.nft_chain_names[_family]['filter']['forward'] ]
for chain_base in chains_family:
if not chain_base: continue
rules_handle = self.get_rules_handle(_family, "filter", chain_base)
if rules_handle is not None:
for r_handle in rules_handle:
is_empty_dict = False
mailcow_rule = {'family':_family,
'table': 'filter',
'chain': chain_base,
'handle': r_handle }
delete_rules = {'delete': {'rule': mailcow_rule} }
json_command["nftables"].append(delete_rules)
# remove chain
# after delete all rules referencing this chain
if chain_handle is not None:
mc_chain_handle = {'family':_family,
'table': 'filter',
'name': self.chain_name,
'handle': chain_handle }
delete_chain = {'delete': {'chain': mc_chain_handle} }
json_command["nftables"].append(delete_chain)
if is_empty_dict == False:
if self.nft_exec_dict(json_command):
self.logger.logInfo(f"Clear completed: {_family}")
def banIPv4(self, source):
ban_dict = self.get_ban_ip_dict(source, "ip")
return self.nft_exec_dict(ban_dict)
def banIPv6(self, source):
ban_dict = self.get_ban_ip_dict(source, "ip6")
return self.nft_exec_dict(ban_dict)
def unbanIPv4(self, source):
unban_dict = self.get_unban_ip_dict(source, "ip")
if not unban_dict:
return False
return self.nft_exec_dict(unban_dict)
def unbanIPv6(self, source):
unban_dict = self.get_unban_ip_dict(source, "ip6")
if not unban_dict:
return False
return self.nft_exec_dict(unban_dict)
def snat4(self, snat_target, source):
self.snat_rule("ip", snat_target, source)
def snat6(self, snat_target, source):
self.snat_rule("ip6", snat_target, source)
def nft_exec_dict(self, query: dict):
if not query: return False
rc, output, error = self.nft.json_cmd(query)
if rc != 0:
#self.logger.logCrit(f"Nftables Error: {error}")
return False
# Prevent returning False or empty string on commands that do not produce output
if rc == 0 and len(output) == 0:
return True
return output
def get_base_dict(self):
return {'nftables': [{ 'metainfo': { 'json_schema_version': 1} } ] }
def search_current_chains(self):
nft_chain_priority = {'ip': {'filter': {'input': None, 'forward': None}, 'nat': {'postrouting': None} },
'ip6': {'filter': {'input': None, 'forward': None}, 'nat': {'postrouting': None} } }
# Command: 'nft list chains'
_list = {'list' : {'chains': 'null'} }
command = self.get_base_dict()
command['nftables'].append(_list)
kernel_ruleset = self.nft_exec_dict(command)
if kernel_ruleset:
for _object in kernel_ruleset['nftables']:
chain = _object.get("chain")
if not chain: continue
_family = chain['family']
_table = chain['table']
_hook = chain.get("hook")
_priority = chain.get("prio")
_name = chain['name']
if _family not in self.nft_chain_names: continue
if _table not in self.nft_chain_names[_family]: continue
if _hook not in self.nft_chain_names[_family][_table]: continue
if _priority is None: continue
_saved_priority = nft_chain_priority[_family][_table][_hook]
if _saved_priority is None or _priority < _saved_priority:
# at this point, we know the chain has:
# hook and priority set
# and it has the lowest priority
nft_chain_priority[_family][_table][_hook] = _priority
self.nft_chain_names[_family][_table][_hook] = _name
def search_for_chain(self, kernel_ruleset: dict, chain_name: str):
found = False
for _object in kernel_ruleset["nftables"]:
chain = _object.get("chain")
if not chain:
continue
ch_name = chain.get("name")
if ch_name == chain_name:
found = True
break
return found
def get_chain_dict(self, _family: str, _name: str):
# nft (add | create) chain [<family>] <table> <name>
_chain_opts = {'family': _family, 'table': 'filter', 'name': _name }
_add = {'add': {'chain': _chain_opts} }
final_chain = self.get_base_dict()
final_chain["nftables"].append(_add)
return final_chain
def get_mailcow_jump_rule_dict(self, _family: str, _chain: str):
_jump_rule = self.get_base_dict()
_expr_opt=[]
_expr_counter = {'family': _family, 'table': 'filter', 'packets': 0, 'bytes': 0}
_counter_dict = {'counter': _expr_counter}
_expr_opt.append(_counter_dict)
_jump_opts = {'jump': {'target': self.chain_name} }
_expr_opt.append(_jump_opts)
_rule_params = {'family': _family,
'table': 'filter',
'chain': _chain,
'expr': _expr_opt,
'comment': "mailcow" }
_add_rule = {'insert': {'rule': _rule_params} }
_jump_rule["nftables"].append(_add_rule)
return _jump_rule
def insert_mailcow_chains(self, _family: str):
nft_input_chain = self.nft_chain_names[_family]['filter']['input']
nft_forward_chain = self.nft_chain_names[_family]['filter']['forward']
# Command: 'nft list table <family> filter'
_table_opts = {'family': _family, 'name': 'filter'}
_list = {'list': {'table': _table_opts} }
command = self.get_base_dict()
command['nftables'].append(_list)
kernel_ruleset = self.nft_exec_dict(command)
if kernel_ruleset:
# chain
if not self.search_for_chain(kernel_ruleset, self.chain_name):
cadena = self.get_chain_dict(_family, self.chain_name)
if self.nft_exec_dict(cadena):
self.logger.logInfo(f"MAILCOW {_family} chain created successfully.")
input_jump_found, forward_jump_found = False, False
for _object in kernel_ruleset["nftables"]:
if not _object.get("rule"):
continue
rule = _object["rule"]
if nft_input_chain and rule["chain"] == nft_input_chain:
if rule.get("comment") and rule["comment"] == "mailcow":
input_jump_found = True
if nft_forward_chain and rule["chain"] == nft_forward_chain:
if rule.get("comment") and rule["comment"] == "mailcow":
forward_jump_found = True
if not input_jump_found:
command = self.get_mailcow_jump_rule_dict(_family, nft_input_chain)
self.nft_exec_dict(command)
if not forward_jump_found:
command = self.get_mailcow_jump_rule_dict(_family, nft_forward_chain)
self.nft_exec_dict(command)
def delete_nat_rule(self, _family:str, _chain: str, _handle:str):
delete_command = self.get_base_dict()
_rule_opts = {'family': _family,
'table': 'nat',
'chain': _chain,
'handle': _handle }
_delete = {'delete': {'rule': _rule_opts} }
delete_command["nftables"].append(_delete)
return self.nft_exec_dict(delete_command)
def snat_rule(self, _family: str, snat_target: str, source_address: str):
chain_name = self.nft_chain_names[_family]['nat']['postrouting']
# no postrouting chain, may occur if docker has ipv6 disabled.
if not chain_name: return
# Command: nft list chain <family> nat <chain_name>
_chain_opts = {'family': _family, 'table': 'nat', 'name': chain_name}
_list = {'list':{'chain': _chain_opts} }
command = self.get_base_dict()
command['nftables'].append(_list)
kernel_ruleset = self.nft_exec_dict(command)
if not kernel_ruleset:
return
rule_position = 0
rule_handle = None
rule_found = False
for _object in kernel_ruleset["nftables"]:
if not _object.get("rule"):
continue
rule = _object["rule"]
if not rule.get("comment") or not rule["comment"] == "mailcow":
rule_position +=1
continue
rule_found = True
rule_handle = rule["handle"]
break
dest_net = ipaddress.ip_network(source_address)
target_net = ipaddress.ip_network(snat_target)
if rule_found:
saddr_ip = rule["expr"][0]["match"]["right"]["prefix"]["addr"]
saddr_len = int(rule["expr"][0]["match"]["right"]["prefix"]["len"])
daddr_ip = rule["expr"][1]["match"]["right"]["prefix"]["addr"]
daddr_len = int(rule["expr"][1]["match"]["right"]["prefix"]["len"])
target_ip = rule["expr"][3]["snat"]["addr"]
saddr_net = ipaddress.ip_network(saddr_ip + '/' + str(saddr_len))
daddr_net = ipaddress.ip_network(daddr_ip + '/' + str(daddr_len))
current_target_net = ipaddress.ip_network(target_ip)
match = all((
dest_net == saddr_net,
dest_net == daddr_net,
target_net == current_target_net
))
try:
if rule_position == 0:
if not match:
# Position 0 , it is a mailcow rule , but it does not have the same parameters
if self.delete_nat_rule(_family, chain_name, rule_handle):
self.logger.logInfo(f'Remove rule for source network {saddr_net} to SNAT target {target_net} from {_family} nat {chain_name} chain, rule does not match configured parameters')
else:
# Position > 0 and is mailcow rule
if self.delete_nat_rule(_family, chain_name, rule_handle):
self.logger.logInfo(f'Remove rule for source network {saddr_net} to SNAT target {target_net} from {_family} nat {chain_name} chain, rule is at position {rule_position}')
except:
self.logger.logCrit(f"Error running SNAT on {_family}, retrying..." )
else:
# rule not found
json_command = self.get_base_dict()
try:
snat_dict = {'snat': {'addr': str(target_net.network_address)} }
expr_counter = {'family': _family, 'table': 'nat', 'packets': 0, 'bytes': 0}
counter_dict = {'counter': expr_counter}
prefix_dict = {'prefix': {'addr': str(dest_net.network_address), 'len': int(dest_net.prefixlen)} }
payload_dict = {'payload': {'protocol': _family, 'field': "saddr"} }
match_dict1 = {'match': {'op': '==', 'left': payload_dict, 'right': prefix_dict} }
payload_dict2 = {'payload': {'protocol': _family, 'field': "daddr"} }
match_dict2 = {'match': {'op': '!=', 'left': payload_dict2, 'right': prefix_dict } }
expr_list = [
match_dict1,
match_dict2,
counter_dict,
snat_dict
]
rule_fields = {'family': _family,
'table': 'nat',
'chain': chain_name,
'comment': "mailcow",
'expr': expr_list }
insert_dict = {'insert': {'rule': rule_fields} }
json_command["nftables"].append(insert_dict)
if self.nft_exec_dict(json_command):
self.logger.logInfo(f'Added {_family} nat {chain_name} rule for source network {dest_net} to {target_net}')
except:
self.logger.logCrit(f"Error running SNAT on {_family}, retrying...")
def get_chain_handle(self, _family: str, _table: str, chain_name: str):
chain_handle = None
# Command: 'nft list chains {family}'
_list = {'list': {'chains': {'family': _family} } }
command = self.get_base_dict()
command['nftables'].append(_list)
kernel_ruleset = self.nft_exec_dict(command)
if kernel_ruleset:
for _object in kernel_ruleset["nftables"]:
if not _object.get("chain"):
continue
chain = _object["chain"]
if chain["family"] == _family and chain["table"] == _table and chain["name"] == chain_name:
chain_handle = chain["handle"]
break
return chain_handle
def get_rules_handle(self, _family: str, _table: str, chain_name: str):
rule_handle = []
# Command: 'nft list chain {family} {table} {chain_name}'
_chain_opts = {'family': _family, 'table': _table, 'name': chain_name}
_list = {'list': {'chain': _chain_opts} }
command = self.get_base_dict()
command['nftables'].append(_list)
kernel_ruleset = self.nft_exec_dict(command)
if kernel_ruleset:
for _object in kernel_ruleset["nftables"]:
if not _object.get("rule"):
continue
rule = _object["rule"]
if rule["family"] == _family and rule["table"] == _table and rule["chain"] == chain_name:
if rule.get("comment") and rule["comment"] == "mailcow":
rule_handle.append(rule["handle"])
return rule_handle
def get_ban_ip_dict(self, ipaddr: str, _family: str):
json_command = self.get_base_dict()
expr_opt = []
ipaddr_net = ipaddress.ip_network(ipaddr)
right_dict = {'prefix': {'addr': str(ipaddr_net.network_address), 'len': int(ipaddr_net.prefixlen) } }
left_dict = {'payload': {'protocol': _family, 'field': 'saddr'} }
match_dict = {'op': '==', 'left': left_dict, 'right': right_dict }
expr_opt.append({'match': match_dict})
counter_dict = {'counter': {'family': _family, 'table': "filter", 'packets': 0, 'bytes': 0} }
expr_opt.append(counter_dict)
expr_opt.append({'drop': "null"})
rule_dict = {'family': _family, 'table': "filter", 'chain': self.chain_name, 'expr': expr_opt}
base_dict = {'insert': {'rule': rule_dict} }
json_command["nftables"].append(base_dict)
return json_command
def get_unban_ip_dict(self, ipaddr:str, _family: str):
json_command = self.get_base_dict()
# Command: 'nft list chain {s_family} filter MAILCOW'
_chain_opts = {'family': _family, 'table': 'filter', 'name': self.chain_name}
_list = {'list': {'chain': _chain_opts} }
command = self.get_base_dict()
command['nftables'].append(_list)
kernel_ruleset = self.nft_exec_dict(command)
rule_handle = None
if kernel_ruleset:
for _object in kernel_ruleset["nftables"]:
if not _object.get("rule"):
continue
rule = _object["rule"]["expr"][0]["match"]
left_opt = rule["left"]["payload"]
if not left_opt["protocol"] == _family:
continue
if not left_opt["field"] =="saddr":
continue
# ip currently banned
rule_right = rule["right"]
if isinstance(rule_right, dict):
current_rule_ip = rule_right["prefix"]["addr"] + '/' + str(rule_right["prefix"]["len"])
else:
current_rule_ip = rule_right
current_rule_net = ipaddress.ip_network(current_rule_ip)
# ip to ban
candidate_net = ipaddress.ip_network(ipaddr)
if current_rule_net == candidate_net:
rule_handle = _object["rule"]["handle"]
break
if rule_handle is not None:
mailcow_rule = {'family': _family, 'table': 'filter', 'chain': self.chain_name, 'handle': rule_handle}
delete_rule = {'delete': {'rule': mailcow_rule} }
json_command["nftables"].append(delete_rule)
else:
return False
return json_command
def check_mailcow_chains(self, family: str, chain: str):
position = 0
rule_found = False
chain_name = self.nft_chain_names[family]['filter'][chain]
if not chain_name: return None
_chain_opts = {'family': family, 'table': 'filter', 'name': chain_name}
_list = {'list': {'chain': _chain_opts}}
command = self.get_base_dict()
command['nftables'].append(_list)
kernel_ruleset = self.nft_exec_dict(command)
if kernel_ruleset:
for _object in kernel_ruleset["nftables"]:
if not _object.get("rule"):
continue
rule = _object["rule"]
if rule.get("comment") and rule["comment"] == "mailcow":
rule_found = True
break
position+=1
return position if rule_found else False

View File

@ -434,7 +434,7 @@ services:
- acme
netfilter-mailcow:
image: mailcow/netfilter:1.52
image: mailcow/netfilter:1.53
stop_grace_period: 30s
depends_on:
- dovecot-mailcow