Merge pull request #5585 from mailcow/feat/nftables

[Netfilter] add nftables support
This commit is contained in:
Patrick Schult 2023-12-11 11:54:01 +01:00 committed by GitHub
commit 3498d4b9c5
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GPG Key ID: 4AEE18F83AFDEB23
8 changed files with 1236 additions and 613 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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@ -13,10 +13,14 @@ from threading import Thread
from threading import Lock
import redis
import json
import iptc
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', '')
@ -31,34 +35,33 @@ while True:
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()
def log(priority, message):
tolog = {}
tolog['time'] = int(round(time.time()))
tolog['priority'] = priority
tolog['message'] = message
r.lpush('NETFILTER_LOG', json.dumps(tolog, ensure_ascii=False))
print(message)
def logWarn(message):
log('warn', message)
# 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 logCrit(message):
log('crit', message)
def logInfo(message):
log('info', message)
def refreshF2boptions():
global f2boptions
@ -79,7 +82,7 @@ def refreshF2boptions():
try:
f2boptions = json.loads(r.get('F2B_OPTIONS'))
except ValueError:
print('Error loading F2B options: F2B_OPTIONS is not json')
logger.logCrit('Error loading F2B options: F2B_OPTIONS is not json')
quit_now = True
exit_code = 2
@ -120,43 +123,22 @@ def refreshF2bregex():
f2bregex = {}
f2bregex = json.loads(r.get('F2B_REGEX'))
except ValueError:
print('Error loading F2B options: F2B_REGEX is not json')
logger.logCrit('Error loading F2B options: F2B_REGEX is not json')
quit_now = True
exit_code = 2
if r.exists('F2B_LOG'):
r.rename('F2B_LOG', 'NETFILTER_LOG')
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
def mailcowChainOrder():
global lock
global quit_now
global exit_code
while not quit_now:
time.sleep(10)
with lock:
filter4_table = iptc.Table(iptc.Table.FILTER)
filter6_table = iptc.Table6(iptc.Table6.FILTER)
filter4_table.refresh()
filter6_table.refresh()
for f in [filter4_table, filter6_table]:
forward_chain = iptc.Chain(f, 'FORWARD')
input_chain = iptc.Chain(f, 'INPUT')
for chain in [forward_chain, input_chain]:
target_found = False
for position, item in enumerate(chain.rules):
if item.target.name == 'MAILCOW':
target_found = True
if position > 2:
logCrit('Error in %s chain order: MAILCOW on position %d, restarting container' % (chain.name, position))
quit_now = True
exit_code = 2
if not target_found:
logCrit('Error in %s chain: MAILCOW target not found, restarting container' % (chain.name))
quit_now = True
exit_code = 2
return ip
def ban(address):
global lock
refreshF2boptions()
BAN_TIME = int(f2boptions['ban_time'])
BAN_TIME_INCREMENT = bool(f2boptions['ban_time_increment'])
@ -165,23 +147,18 @@ def ban(address):
NETBAN_IPV4 = '/' + str(f2boptions['netban_ipv4'])
NETBAN_IPV6 = '/' + str(f2boptions['netban_ipv6'])
ip = ipaddress.ip_address(address)
if type(ip) is ipaddress.IPv6Address and ip.ipv4_mapped:
ip = ip.ipv4_mapped
ip = get_ip(address)
if not ip: return
address = str(ip)
if ip.is_private or ip.is_loopback:
return
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):
logInfo('Address %s is whitelisted by rule %s' % (self_network, wl_net))
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)
@ -190,60 +167,44 @@ def ban(address):
if not net in bans:
bans[net] = {'attempts': 0, 'last_attempt': 0, 'ban_counter': 0}
current_attempt = time.time()
if current_attempt - bans[net]['last_attempt'] > RETRY_WINDOW:
bans[net]['attempts'] = 0
bans[net]['attempts'] += 1
bans[net]['last_attempt'] = time.time()
bans[net]['last_attempt'] = current_attempt
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']
logCrit('Banning %s for %d minutes' % (net, NET_BAN_TIME / 60 ))
logger.logCrit('Banning %s for %d minutes' % (net, NET_BAN_TIME / 60 ))
if type(ip) is ipaddress.IPv4Address:
with lock:
chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), 'MAILCOW')
rule = iptc.Rule()
rule.src = net
target = iptc.Target(rule, "REJECT")
rule.target = target
if rule not in chain.rules:
chain.insert_rule(rule)
tables.banIPv4(net)
else:
with lock:
chain = iptc.Chain(iptc.Table6(iptc.Table6.FILTER), 'MAILCOW')
rule = iptc.Rule6()
rule.src = net
target = iptc.Target(rule, "REJECT")
rule.target = target
if rule not in chain.rules:
chain.insert_rule(rule)
tables.banIPv6(net)
r.hset('F2B_ACTIVE_BANS', '%s' % net, cur_time + NET_BAN_TIME)
else:
logWarn('%d more attempts in the next %d seconds until %s is banned' % (MAX_ATTEMPTS - bans[net]['attempts'], RETRY_WINDOW, net))
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:
logInfo('%s is not banned, skipping unban and deleting from queue (if any)' % net)
logger.logInfo('%s is not banned, skipping unban and deleting from queue (if any)' % net)
r.hdel('F2B_QUEUE_UNBAN', '%s' % net)
return
logInfo('Unbanning %s' % net)
logger.logInfo('Unbanning %s' % net)
if type(ipaddress.ip_network(net)) is ipaddress.IPv4Network:
with lock:
chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), 'MAILCOW')
rule = iptc.Rule()
rule.src = net
target = iptc.Target(rule, "REJECT")
rule.target = target
if rule in chain.rules:
chain.delete_rule(rule)
tables.unbanIPv4(net)
else:
with lock:
chain = iptc.Chain(iptc.Table6(iptc.Table6.FILTER), 'MAILCOW')
rule = iptc.Rule6()
rule.src = net
target = iptc.Target(rule, "REJECT")
rule.target = target
if rule in chain.rules:
chain.delete_rule(rule)
tables.unbanIPv6(net)
r.hdel('F2B_ACTIVE_BANS', '%s' % net)
r.hdel('F2B_QUEUE_UNBAN', '%s' % net)
if net in bans:
@ -252,73 +213,44 @@ def unban(net):
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:
chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), 'MAILCOW')
rule = iptc.Rule()
rule.src = net
target = iptc.Target(rule, "REJECT")
rule.target = target
if rule not in chain.rules and not unban:
logCrit('Add host/network %s to blacklist' % net)
chain.insert_rule(rule)
r.hset('F2B_PERM_BANS', '%s' % net, int(round(time.time())))
elif rule in chain.rules and unban:
logCrit('Remove host/network %s from blacklist' % net)
chain.delete_rule(rule)
r.hdel('F2B_PERM_BANS', '%s' % net)
if unban:
is_unbanned = tables.unbanIPv4(net)
else:
is_banned = tables.banIPv4(net)
else:
with lock:
chain = iptc.Chain(iptc.Table6(iptc.Table6.FILTER), 'MAILCOW')
rule = iptc.Rule6()
rule.src = net
target = iptc.Target(rule, "REJECT")
rule.target = target
if rule not in chain.rules and not unban:
logCrit('Add host/network %s to blacklist' % net)
chain.insert_rule(rule)
r.hset('F2B_PERM_BANS', '%s' % net, int(round(time.time())))
elif rule in chain.rules and unban:
logCrit('Remove host/network %s from blacklist' % net)
chain.delete_rule(rule)
r.hdel('F2B_PERM_BANS', '%s' % net)
if unban:
is_unbanned = tables.unbanIPv6(net)
else:
is_banned = tables.banIPv6(net)
def quit(signum, frame):
global quit_now
quit_now = True
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
logInfo('Clearing all bans')
logger.logInfo('Clearing all bans')
for net in bans.copy():
unban(net)
with lock:
filter4_table = iptc.Table(iptc.Table.FILTER)
filter6_table = iptc.Table6(iptc.Table6.FILTER)
for filter_table in [filter4_table, filter6_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, "MAILCOW")
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 == 'MAILCOW':
forward_chain.delete_rule(rule)
for rule in input_chain.rules:
if rule.target.name == 'MAILCOW':
input_chain.delete_rule(rule)
filter_table.delete_chain("MAILCOW")
filter_table.commit()
filter_table.refresh()
filter_table.autocommit = True
tables.clearIPv4Table()
tables.clearIPv6Table()
r.delete('F2B_ACTIVE_BANS')
r.delete('F2B_PERM_BANS')
pubsub.unsubscribe()
def watch():
logInfo('Watching Redis channel F2B_CHANNEL')
logger.logInfo('Watching Redis channel F2B_CHANNEL')
pubsub.subscribe('F2B_CHANNEL')
global quit_now
@ -339,10 +271,10 @@ def watch():
ip = ipaddress.ip_address(addr)
if ip.is_private or ip.is_loopback:
continue
logWarn('%s matched rule id %s (%s)' % (addr, rule_id, item['data']))
logger.logWarn('%s matched rule id %s (%s)' % (addr, rule_id, item['data']))
ban(addr)
except Exception as ex:
logWarn('Error reading log line from pubsub: %s' % ex)
logger.logWarn('Error reading log line from pubsub: %s' % ex)
quit_now = True
exit_code = 2
@ -350,87 +282,19 @@ def snat4(snat_target):
global lock
global quit_now
def get_snat4_rule():
rule = iptc.Rule()
rule.src = os.getenv('IPV4_NETWORK', '172.22.1') + '.0/24'
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
while not quit_now:
time.sleep(10)
with lock:
try:
table = iptc.Table('nat')
table.refresh()
chain = iptc.Chain(table, 'POSTROUTING')
table.autocommit = False
new_rule = get_snat4_rule()
if not chain.rules:
# if there are no rules in the chain, insert the new rule directly
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:
logInfo(f'Added POSTROUTING rule for source network {new_rule.src} to SNAT target {snat_target}')
chain.insert_rule(new_rule)
else:
if match:
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
except:
print('Error running SNAT4, retrying...')
tables.snat4(snat_target, os.getenv('IPV4_NETWORK', '172.22.1') + '.0/24')
def snat6(snat_target):
global lock
global quit_now
def get_snat6_rule():
rule = iptc.Rule6()
rule.src = os.getenv('IPV6_NETWORK', 'fd4d:6169:6c63:6f77::/64')
rule.dst = '!' + rule.src
target = rule.create_target("SNAT")
target.to_source = snat_target
return rule
while not quit_now:
time.sleep(10)
with lock:
try:
table = iptc.Table6('nat')
table.refresh()
chain = iptc.Chain(table, 'POSTROUTING')
table.autocommit = False
if get_snat6_rule() not in chain.rules:
logInfo('Added POSTROUTING rule for source network %s to SNAT target %s' % (get_snat6_rule().src, snat_target))
chain.insert_rule(get_snat6_rule())
table.commit()
else:
for position, item in enumerate(chain.rules):
if item == get_snat6_rule():
if position != 0:
chain.delete_rule(get_snat6_rule())
table.commit()
table.autocommit = True
except:
print('Error running SNAT6, retrying...')
tables.snat6(snat_target, os.getenv('IPV6_NETWORK', 'fd4d:6169:6c63:6f77::/64'))
def autopurge():
while not quit_now:
@ -451,6 +315,17 @@ def autopurge():
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)
@ -458,7 +333,6 @@ def isIpNetwork(address):
return False
return True
def genNetworkList(list):
resolver = dns.resolver.Resolver()
hostnames = []
@ -474,12 +348,12 @@ def genNetworkList(list):
try:
answer = resolver.resolve(qname=hostname, rdtype=rdtype, lifetime=3)
except dns.exception.Timeout:
logInfo('Hostname %s timedout on resolve' % hostname)
logger.logInfo('Hostname %s timedout on resolve' % hostname)
break
except (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer):
continue
except dns.exception.DNSException as dnsexception:
logInfo('%s' % dnsexception)
logger.logInfo('%s' % dnsexception)
continue
for rdata in answer:
hostname_ips.append(rdata.to_text())
@ -499,7 +373,7 @@ def whitelistUpdate():
with lock:
if Counter(new_whitelist) != Counter(WHITELIST):
WHITELIST = new_whitelist
logInfo('Whitelist was changed, it has %s entries' % len(WHITELIST))
logger.logInfo('Whitelist was changed, it has %s entries' % len(WHITELIST))
time.sleep(60.0 - ((time.time() - start_time) % 60.0))
def blacklistUpdate():
@ -515,7 +389,7 @@ def blacklistUpdate():
addban = set(new_blacklist).difference(BLACKLIST)
delban = set(BLACKLIST).difference(new_blacklist)
BLACKLIST = new_blacklist
logInfo('Blacklist was changed, it has %s entries' % len(BLACKLIST))
logger.logInfo('Blacklist was changed, it has %s entries' % len(BLACKLIST))
if addban:
for net in addban:
permBan(net=net)
@ -524,40 +398,19 @@ def blacklistUpdate():
permBan(net=net, unban=True)
time.sleep(60.0 - ((time.time() - start_time) % 60.0))
def initChain():
# Is called before threads start, no locking
print("Initializing mailcow netfilter chain")
# IPv4
if not iptc.Chain(iptc.Table(iptc.Table.FILTER), "MAILCOW") in iptc.Table(iptc.Table.FILTER).chains:
iptc.Table(iptc.Table.FILTER).create_chain("MAILCOW")
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, "MAILCOW")
rule.target = target
if rule not in chain.rules:
chain.insert_rule(rule)
# IPv6
if not iptc.Chain(iptc.Table6(iptc.Table6.FILTER), "MAILCOW") in iptc.Table6(iptc.Table6.FILTER).chains:
iptc.Table6(iptc.Table6.FILTER).create_chain("MAILCOW")
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, "MAILCOW")
rule.target = target
if rule not in chain.rules:
chain.insert_rule(rule)
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
initChain()
# 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

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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

View File

@ -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