EVOLUTION-NINJA

Edit File: fw.py

# -*- coding: utf-8 -*-
#
# Copyright (C) 2010-2016 Red Hat, Inc.
#
# Authors:
# Thomas Woerner <twoerner@redhat.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

__all__ = [ "Firewall" ]

import os.path
import sys
import copy
import time
import traceback
from firewall import config
from firewall import functions
from firewall.core import ipXtables
from firewall.core import ebtables
from firewall.core import nftables
from firewall.core import ipset
from firewall.core import modules
from firewall.core.fw_icmptype import FirewallIcmpType
from firewall.core.fw_service import FirewallService
from firewall.core.fw_zone import FirewallZone
from firewall.core.fw_direct import FirewallDirect
from firewall.core.fw_config import FirewallConfig
from firewall.core.fw_policies import FirewallPolicies
from firewall.core.fw_ipset import FirewallIPSet
from firewall.core.fw_transaction import FirewallTransaction
from firewall.core.fw_helper import FirewallHelper
from firewall.core.fw_policy import FirewallPolicy
from firewall.core.fw_nm import nm_get_bus_name, nm_get_interfaces_in_zone
from firewall.core.logger import log
from firewall.core.io.firewalld_conf import firewalld_conf
from firewall.core.io.direct import Direct
from firewall.core.io.service import service_reader
from firewall.core.io.icmptype import icmptype_reader
from firewall.core.io.zone import zone_reader, Zone
from firewall.core.io.ipset import ipset_reader
from firewall.core.ipset import IPSET_TYPES
from firewall.core.io.helper import helper_reader
from firewall.core.io.policy import policy_reader
from firewall import errors
from firewall.errors import FirewallError

############################################################################
#
# class Firewall
#
############################################################################

class Firewall(object):
    def __init__(self, offline=False):
        self._firewalld_conf = firewalld_conf(config.FIREWALLD_CONF)
        self._offline = offline

if self._offline:
            self.ip4tables_enabled = False
            self.ip6tables_enabled = False
            self.ebtables_enabled = False
            self.ipset_enabled = False
            self.ipset_supported_types = IPSET_TYPES
            self.nftables_enabled = False
        else:
            self.ip4tables_backend = ipXtables.ip4tables(self)
            self.ip4tables_enabled = True
            self.ipv4_supported_icmp_types = [ ]
            self.ip6tables_backend = ipXtables.ip6tables(self)
            self.ip6tables_enabled = True
            self.ipv6_supported_icmp_types = [ ]
            self.ebtables_backend = ebtables.ebtables()
            self.ebtables_enabled = True
            self.ipset_backend = ipset.ipset()
            self.ipset_enabled = True
            self.ipset_supported_types = [ ]
            self.nftables_backend = nftables.nftables(self)
            self.nftables_enabled = True

self.modules_backend = modules.modules()

self.icmptype = FirewallIcmpType(self)
        self.service = FirewallService(self)
        self.zone = FirewallZone(self)
        self.direct = FirewallDirect(self)
        self.config = FirewallConfig(self)
        self.policies = FirewallPolicies()
        self.ipset = FirewallIPSet(self)
        self.helper = FirewallHelper(self)
        self.policy = FirewallPolicy(self)

self.__init_vars()

def __repr__(self):
        return '%s(%r, %r, %r, %r, %r, %r, %r, %r, %r, %r, %r, %r, %r, %r)' % \
            (self.__class__, self.ip4tables_enabled, self.ip6tables_enabled,
             self.ebtables_enabled, self._state, self._panic,
             self._default_zone, self._module_refcount, self._marks,
             self.cleanup_on_exit, self.cleanup_modules_on_exit,
             self.ipv6_rpfilter_enabled, self.ipset_enabled,
             self._individual_calls, self._log_denied)

def __init_vars(self):
        self._state = "INIT"
        self._panic = False
        self._default_zone = ""
        self._module_refcount = { }
        self._marks = [ ]
        # fallback settings will be overloaded by firewalld.conf
        self.cleanup_on_exit = config.FALLBACK_CLEANUP_ON_EXIT
        self.cleanup_modules_on_exit = config.FALLBACK_CLEANUP_MODULES_ON_EXIT
        self.ipv6_rpfilter_enabled = config.FALLBACK_IPV6_RPFILTER
        self._individual_calls = config.FALLBACK_INDIVIDUAL_CALLS
        self._log_denied = config.FALLBACK_LOG_DENIED
        self._firewall_backend = config.FALLBACK_FIREWALL_BACKEND
        self._flush_all_on_reload = config.FALLBACK_FLUSH_ALL_ON_RELOAD
        self._rfc3964_ipv4 = config.FALLBACK_RFC3964_IPV4
        self._allow_zone_drifting = config.FALLBACK_ALLOW_ZONE_DRIFTING

def _check_tables(self):
        # check if iptables, ip6tables and ebtables are usable, else disable
        if self.ip4tables_enabled and \
           "filter" not in self.ip4tables_backend.get_available_tables():
            log.info1("iptables is not usable.")
            self.ip4tables_enabled = False

if self.ip6tables_enabled and \
           "filter" not in self.ip6tables_backend.get_available_tables():
            log.info1("ip6tables is not usable.")
            self.ip6tables_enabled = False

if self.ebtables_enabled and \
           "filter" not in self.ebtables_backend.get_available_tables():
            log.info1("ebtables is not usable.")
            self.ebtables_enabled = False

# is there at least support for ipv4 or ipv6
        if not self.ip4tables_enabled and not self.ip6tables_enabled \
           and not self.nftables_enabled:
            log.fatal("No IPv4 and IPv6 firewall.")
            sys.exit(1)

def _start_check(self):
        try:
            self.ipset_backend.set_list()
        except ValueError:
            log.warning("ipset not usable, disabling ipset usage in firewall.")
            # ipset is not usable, no supported types
            self.ipset_enabled = False
            self.ipset_supported_types = [ ]
        else:
            # ipset is usable, get all supported types
            self.ipset_supported_types = self.ipset_backend.set_supported_types()

self.ip4tables_backend.fill_exists()
        if not self.ip4tables_backend.restore_command_exists:
            if self.ip4tables_backend.command_exists:
                log.warning("iptables-restore is missing, using "
                            "individual calls for IPv4 firewall.")
            else:
                log.warning("iptables-restore and iptables are missing, "
                            "disabling IPv4 firewall.")
                self.ip4tables_enabled = False
        if self.nftables_enabled:
            self.ipv4_supported_icmp_types = self.nftables_backend.supported_icmp_types("ipv4")
        else:
            if self.ip4tables_enabled:
                self.ipv4_supported_icmp_types = self.ip4tables_backend.supported_icmp_types()
            else:
                self.ipv4_supported_icmp_types = [ ]
        self.ip6tables_backend.fill_exists()
        if not self.ip6tables_backend.restore_command_exists:
            if self.ip6tables_backend.command_exists:
                log.warning("ip6tables-restore is missing, using "
                            "individual calls for IPv6 firewall.")
            else:
                log.warning("ip6tables-restore and ip6tables are missing, "
                            "disabling IPv6 firewall.")
                self.ip6tables_enabled = False
        if self.nftables_enabled:
            self.ipv6_supported_icmp_types = self.nftables_backend.supported_icmp_types("ipv6")
        else:
            if self.ip6tables_enabled:
                self.ipv6_supported_icmp_types = self.ip6tables_backend.supported_icmp_types()
            else:
                self.ipv6_supported_icmp_types = [ ]
        self.ebtables_backend.fill_exists()
        if not self.ebtables_backend.restore_command_exists:
            if self.ebtables_backend.command_exists:
                log.warning("ebtables-restore is missing, using "
                            "individual calls for bridge firewall.")
            else:
                log.warning("ebtables-restore and ebtables are missing, "
                            "disabling bridge firewall.")
                self.ebtables_enabled = False

if self.ebtables_enabled and not self._individual_calls and \
           not self.ebtables_backend.restore_noflush_option:
            log.debug1("ebtables-restore is not supporting the --noflush "
                       "option, will therefore not be used")

def _start(self, reload=False, complete_reload=False):
        # initialize firewall
        default_zone = config.FALLBACK_ZONE

# load firewalld config
        log.debug1("Loading firewalld config file '%s'", config.FIREWALLD_CONF)
        try:
            self._firewalld_conf.read()
        except Exception as msg:
            log.warning(msg)
            log.warning("Using fallback firewalld configuration settings.")
        else:
            if self._firewalld_conf.get("DefaultZone"):
                default_zone = self._firewalld_conf.get("DefaultZone")

if self._firewalld_conf.get("CleanupOnExit"):
                value = self._firewalld_conf.get("CleanupOnExit")
                if value is not None and value.lower() in [ "no", "false" ]:
                    self.cleanup_on_exit = False
                log.debug1("CleanupOnExit is set to '%s'",
                           self.cleanup_on_exit)

if self._firewalld_conf.get("CleanupModulesOnExit"):
                value = self._firewalld_conf.get("CleanupModulesOnExit")
                if value is not None and value.lower() in [ "yes", "true" ]:
                    self.cleanup_modules_on_exit = True
                if value is not None and value.lower() in [ "no", "false" ]:
                    self.cleanup_modules_on_exit = False
                log.debug1("CleanupModulesOnExit is set to '%s'",
                           self.cleanup_modules_on_exit)

if self._firewalld_conf.get("Lockdown"):
                value = self._firewalld_conf.get("Lockdown")
                if value is not None and value.lower() in [ "yes", "true" ]:
                    log.debug1("Lockdown is enabled")
                    try:
                        self.policies.enable_lockdown()
                    except FirewallError:
                        # already enabled, this is probably reload
                        pass

if self._firewalld_conf.get("IPv6_rpfilter"):
                value = self._firewalld_conf.get("IPv6_rpfilter")
                if value is not None:
                    if value.lower() in [ "no", "false" ]:
                        self.ipv6_rpfilter_enabled = False
                    if value.lower() in [ "yes", "true" ]:
                        self.ipv6_rpfilter_enabled = True
            if self.ipv6_rpfilter_enabled:
                log.debug1("IPv6 rpfilter is enabled")
            else:
                log.debug1("IPV6 rpfilter is disabled")

if self._firewalld_conf.get("IndividualCalls"):
                value = self._firewalld_conf.get("IndividualCalls")
                if value is not None and value.lower() in [ "yes", "true" ]:
                    log.debug1("IndividualCalls is enabled")
                    self._individual_calls = True

if self._firewalld_conf.get("LogDenied"):
                value = self._firewalld_conf.get("LogDenied")
                if value is None or value.lower() == "no":
                    self._log_denied = "off"
                else:
                    self._log_denied = value.lower()
                    log.debug1("LogDenied is set to '%s'", self._log_denied)

if self._firewalld_conf.get("FirewallBackend"):
                self._firewall_backend = self._firewalld_conf.get("FirewallBackend")
                log.debug1("FirewallBackend is set to '%s'",
                           self._firewall_backend)

if self._firewalld_conf.get("FlushAllOnReload"):
                value = self._firewalld_conf.get("FlushAllOnReload")
                if value.lower() in [ "no", "false" ]:
                    self._flush_all_on_reload = False
                else:
                    self._flush_all_on_reload = True
                log.debug1("FlushAllOnReload is set to '%s'",
                           self._flush_all_on_reload)

if self._firewalld_conf.get("RFC3964_IPv4"):
                value = self._firewalld_conf.get("RFC3964_IPv4")
                if value.lower() in [ "no", "false" ]:
                    self._rfc3964_ipv4 = False
                else:
                    self._rfc3964_ipv4 = True
                log.debug1("RFC3964_IPv4 is set to '%s'",
                           self._rfc3964_ipv4)

if self._firewalld_conf.get("AllowZoneDrifting"):
                value = self._firewalld_conf.get("AllowZoneDrifting")
                if value.lower() in [ "no", "false" ]:
                    self._allow_zone_drifting = False
                else:
                    self._allow_zone_drifting = True
                    if not self._offline:
                        log.warning("AllowZoneDrifting is enabled. This is considered "
                                    "an insecure configuration option. It will be "
                                    "removed in a future release. Please consider "
                                    "disabling it now.")
                log.debug1("AllowZoneDrifting is set to '%s'",
                           self._allow_zone_drifting)

self.config.set_firewalld_conf(copy.deepcopy(self._firewalld_conf))

self._select_firewall_backend(self._firewall_backend)

if not self._offline:
            self._start_check()

# load lockdown whitelist
        log.debug1("Loading lockdown whitelist")
        try:
            self.policies.lockdown_whitelist.read()
        except Exception as msg:
            if self.policies.query_lockdown():
                log.error("Failed to load lockdown whitelist '%s': %s",
                          self.policies.lockdown_whitelist.filename, msg)
            else:
                log.debug1("Failed to load lockdown whitelist '%s': %s",
                           self.policies.lockdown_whitelist.filename, msg)

# copy policies to config interface
        self.config.set_policies(copy.deepcopy(self.policies))

# load ipset files
        self._loader(config.FIREWALLD_IPSETS, "ipset")
        self._loader(config.ETC_FIREWALLD_IPSETS, "ipset")

# load icmptype files
        self._loader(config.FIREWALLD_ICMPTYPES, "icmptype")
        self._loader(config.ETC_FIREWALLD_ICMPTYPES, "icmptype")

if len(self.icmptype.get_icmptypes()) == 0:
            log.error("No icmptypes found.")

# load helper files
        self._loader(config.FIREWALLD_HELPERS, "helper")
        self._loader(config.ETC_FIREWALLD_HELPERS, "helper")

# load service files
        self._loader(config.FIREWALLD_SERVICES, "service")
        self._loader(config.ETC_FIREWALLD_SERVICES, "service")

if len(self.service.get_services()) == 0:
            log.error("No services found.")

# load zone files
        self._loader(config.FIREWALLD_ZONES, "zone")
        self._loader(config.ETC_FIREWALLD_ZONES, "zone")

if len(self.zone.get_zones()) == 0:
            log.fatal("No zones found.")
            sys.exit(1)

# load policy files
        self._loader(config.FIREWALLD_POLICIES, "policy")
        self._loader(config.ETC_FIREWALLD_POLICIES, "policy")

# check minimum required zones
        error = False
        for z in [ "block", "drop", "trusted" ]:
            if z not in self.zone.get_zones():
                log.fatal("Zone '%s' is not available.", z)
                error = True
        if error:
            sys.exit(1)

# check if default_zone is a valid zone
        if default_zone not in self.zone.get_zones():
            if "public" in self.zone.get_zones():
                zone = "public"
            elif "external" in self.zone.get_zones():
                zone = "external"
            else:
                zone = "block" # block is a base zone, therefore it has to exist

log.error("Default zone '%s' is not valid. Using '%s'.",
                      default_zone, zone)
            default_zone = zone
        else:
            log.debug1("Using default zone '%s'", default_zone)

# load direct rules
        obj = Direct(config.FIREWALLD_DIRECT)
        if os.path.exists(config.FIREWALLD_DIRECT):
            log.debug1("Loading direct rules file '%s'" % \
                       config.FIREWALLD_DIRECT)
            try:
                obj.read()
            except Exception as msg:
                log.error("Failed to load direct rules file '%s': %s",
                          config.FIREWALLD_DIRECT, msg)
        self.direct.set_permanent_config(obj)
        self.config.set_direct(copy.deepcopy(obj))

self._default_zone = self.check_zone(default_zone)

if self._offline:
            return

# check if needed tables are there
        self._check_tables()

if log.getDebugLogLevel() > 0:
            # get time before flushing and applying
            tm1 = time.time()

# Start transaction
        transaction = FirewallTransaction(self)

# flush rules
        if not reload:
            self.flush(use_transaction=transaction)

# If modules need to be unloaded in complete reload or if there are
        # ipsets to get applied, limit the transaction to flush.
        #
        # Future optimization for the ipset case in reload: The transaction
        # only needs to be split here if there are conflicting ipset types in
        # exsting ipsets and the configuration in firewalld.
        if (reload and complete_reload) or \
           (self.ipset_enabled and self.ipset.has_ipsets()):
            transaction.execute(True)
            transaction.clear()

# complete reload: unload modules also
        if reload and complete_reload:
            log.debug1("Unloading firewall modules")
            self.modules_backend.unload_firewall_modules()

self.apply_default_tables(use_transaction=transaction)
        transaction.execute(True)
        transaction.clear()

# apply settings for loaded ipsets while reloading here
        if self.ipset_enabled and self.ipset.has_ipsets():
            log.debug1("Applying ipsets")
            self.ipset.apply_ipsets()

# Start or continue with transaction

# apply default rules
        log.debug1("Applying default rule set")
        self.apply_default_rules(use_transaction=transaction)

# apply settings for loaded zones
        log.debug1("Applying used zones")
        self.zone.apply_zones(use_transaction=transaction)

self.zone.change_default_zone(None, self._default_zone,
                                      use_transaction=transaction)

# apply policies
        log.debug1("Applying used policies")
        self.policy.apply_policies(use_transaction=transaction)

# Execute transaction
        transaction.execute(True)

# Start new transaction for direct rules
        transaction.clear()

# apply direct chains, rules and passthrough rules
        if self.direct.has_configuration():
            log.debug1("Applying direct chains rules and passthrough rules")
            self.direct.apply_direct(transaction)

# since direct rules are easy to make syntax errors lets highlight
            # the cause if the transaction fails.
            try:
                transaction.execute(True)
                transaction.clear()
            except FirewallError as e:
                raise FirewallError(e.code, "Direct: %s" % (e.msg if e.msg else ""))
            except Exception:
                raise

del transaction

if log.getDebugLogLevel() > 1:
            # get time after flushing and applying
            tm2 = time.time()
            log.debug2("Flushing and applying took %f seconds" % (tm2 - tm1))

def start(self):
        try:
            self._start()
        except Exception:
            self._state = "FAILED"
            self.set_policy("ACCEPT")
            raise
        else:
            self._state = "RUNNING"
            self.set_policy("ACCEPT")

def _loader(self, path, reader_type, combine=False):
        # combine: several zone files are getting combined into one obj
        if not os.path.isdir(path):
            return

if combine:
            if path.startswith(config.ETC_FIREWALLD) and reader_type == "zone":
                combined_zone = Zone()
                combined_zone.name = os.path.basename(path)
                combined_zone.check_name(combined_zone.name)
                combined_zone.path = path
                combined_zone.default = False
            else:
                combine = False

for filename in sorted(os.listdir(path)):
            if not filename.endswith(".xml"):
                if path.startswith(config.ETC_FIREWALLD) and \
                        reader_type == "zone" and \
                        os.path.isdir("%s/%s" % (path, filename)):
                    self._loader("%s/%s" % (path, filename), reader_type,
                                 combine=True)
                continue

name = "%s/%s" % (path, filename)
            log.debug1("Loading %s file '%s'", reader_type, name)
            try:
                if reader_type == "icmptype":
                    obj = icmptype_reader(filename, path)
                    if obj.name in self.icmptype.get_icmptypes():
                        orig_obj = self.icmptype.get_icmptype(obj.name)
                        log.debug1("  Overloads %s '%s' ('%s/%s')", reader_type,
                                   orig_obj.name, orig_obj.path,
                                   orig_obj.filename)
                        self.icmptype.remove_icmptype(orig_obj.name)
                    elif obj.path.startswith(config.ETC_FIREWALLD):
                        obj.default = True
                    try:
                        self.icmptype.add_icmptype(obj)
                    except FirewallError as error:
                        log.info1("%s: %s, ignoring for run-time." % \
                                    (obj.name, str(error)))
                    # add a deep copy to the configuration interface
                    self.config.add_icmptype(copy.deepcopy(obj))
                elif reader_type == "service":
                    obj = service_reader(filename, path)
                    if obj.name in self.service.get_services():
                        orig_obj = self.service.get_service(obj.name)
                        log.debug1("  Overloads %s '%s' ('%s/%s')", reader_type,
                                   orig_obj.name, orig_obj.path,
                                   orig_obj.filename)
                        self.service.remove_service(orig_obj.name)
                    elif obj.path.startswith(config.ETC_FIREWALLD):
                        obj.default = True
                    self.service.add_service(obj)
                    # add a deep copy to the configuration interface
                    self.config.add_service(copy.deepcopy(obj))
                elif reader_type == "zone":
                    obj = zone_reader(filename, path, no_check_name=combine)
                    if combine:
                        # Change name for permanent configuration
                        obj.name = "%s/%s" % (
                            os.path.basename(path),
                            os.path.basename(filename)[0:-4])
                        obj.check_name(obj.name)
                    # Copy object before combine
                    config_obj = copy.deepcopy(obj)
                    if obj.name in self.zone.get_zones():
                        orig_obj = self.zone.get_zone(obj.name)
                        self.zone.remove_zone(orig_obj.name)
                        if orig_obj.combined:
                            log.debug1("  Combining %s '%s' ('%s/%s')",
                                        reader_type, obj.name,
                                        path, filename)
                            obj.combine(orig_obj)
                        else:
                            log.debug1("  Overloads %s '%s' ('%s/%s')",
                                       reader_type,
                                       orig_obj.name, orig_obj.path,
                                       orig_obj.filename)
                    elif obj.path.startswith(config.ETC_FIREWALLD):
                        obj.default = True
                        config_obj.default = True
                    self.config.add_zone(config_obj)
                    if combine:
                        log.debug1("  Combining %s '%s' ('%s/%s')",
                                   reader_type, combined_zone.name,
                                   path, filename)
                        combined_zone.combine(obj)
                    else:
                        self.zone.add_zone(obj)
                elif reader_type == "ipset":
                    obj = ipset_reader(filename, path)
                    if obj.name in self.ipset.get_ipsets():
                        orig_obj = self.ipset.get_ipset(obj.name)
                        log.debug1("  Overloads %s '%s' ('%s/%s')", reader_type,
                                   orig_obj.name, orig_obj.path,
                                   orig_obj.filename)
                        self.ipset.remove_ipset(orig_obj.name)
                    elif obj.path.startswith(config.ETC_FIREWALLD):
                        obj.default = True
                    try:
                        self.ipset.add_ipset(obj)
                    except FirewallError as error:
                        log.warning("%s: %s, ignoring for run-time." % \
                                    (obj.name, str(error)))
                    # add a deep copy to the configuration interface
                    self.config.add_ipset(copy.deepcopy(obj))
                elif reader_type == "helper":
                    obj = helper_reader(filename, path)
                    if obj.name in self.helper.get_helpers():
                        orig_obj = self.helper.get_helper(obj.name)
                        log.debug1("  Overloads %s '%s' ('%s/%s')", reader_type,
                                   orig_obj.name, orig_obj.path,
                                   orig_obj.filename)
                        self.helper.remove_helper(orig_obj.name)
                    elif obj.path.startswith(config.ETC_FIREWALLD):
                        obj.default = True
                    self.helper.add_helper(obj)
                    # add a deep copy to the configuration interface
                    self.config.add_helper(copy.deepcopy(obj))
                elif reader_type == "policy":
                    obj = policy_reader(filename, path)
                    if obj.name in self.policy.get_policies():
                        orig_obj = self.policy.get_policy(obj.name)
                        log.debug1("  Overloads %s '%s' ('%s/%s')", reader_type,
                                   orig_obj.name, orig_obj.path,
                                   orig_obj.filename)
                        self.policy.remove_policy(orig_obj.name)
                    elif obj.path.startswith(config.ETC_FIREWALLD):
                        obj.default = True
                    self.policy.add_policy(obj)
                    # add a deep copy to the configuration interface
                    self.config.add_policy_object(copy.deepcopy(obj))
                else:
                    log.fatal("Unknown reader type %s", reader_type)
            except FirewallError as msg:
                log.error("Failed to load %s file '%s': %s", reader_type,
                          name, msg)
            except Exception:
                log.error("Failed to load %s file '%s':", reader_type, name)
                log.exception()

if combine and combined_zone.combined:
            if combined_zone.name in self.zone.get_zones():
                orig_obj = self.zone.get_zone(combined_zone.name)
                log.debug1("  Overloading and deactivating %s '%s' ('%s/%s')",
                           reader_type, orig_obj.name, orig_obj.path,
                           orig_obj.filename)
                try:
                    self.zone.remove_zone(combined_zone.name)
                except Exception:
                    pass
                self.config.forget_zone(combined_zone.name)
            self.zone.add_zone(combined_zone)

def cleanup(self):
        self.icmptype.cleanup()
        self.service.cleanup()
        self.zone.cleanup()
        self.ipset.cleanup()
        self.helper.cleanup()
        self.config.cleanup()
        self.direct.cleanup()
        self.policies.cleanup()
        self.policy.cleanup()
        self._firewalld_conf.cleanup()
        self.__init_vars()

def stop(self):
        if not self._offline:
            if self.cleanup_on_exit:
                self.flush()
                self.ipset.flush()
                self.set_policy("ACCEPT")

if self.cleanup_modules_on_exit:
                log.debug1('Unloading firewall kernel modules')
                self.modules_backend.unload_firewall_modules()

self.cleanup()

# handle modules

def handle_modules(self, _modules, enable):
        num_failed = 0
        error_msgs = ""
        for i,module in enumerate(_modules):
            if enable:
                (status, msg) = self.modules_backend.load_module(module)
            else:
                if self._module_refcount[module] > 1:
                    status = 0 # module referenced more then one, do not unload
                else:
                    (status, msg) = self.modules_backend.unload_module(module)
            if status != 0:
                num_failed += 1
                error_msgs += msg
                continue

if enable:
                self._module_refcount.setdefault(module, 0)
                self._module_refcount[module] += 1
            else:
                if module in self._module_refcount:
                    self._module_refcount[module] -= 1
                    if self._module_refcount[module] == 0:
                        del self._module_refcount[module]
        return (num_failed, error_msgs)

def _select_firewall_backend(self, backend):
        if backend != "nftables":
            self.nftables_enabled = False
        # even if using nftables, the other backends are enabled for use with
        # the direct interface. nftables is used for the firewalld primitives.

def get_backend_by_name(self, name):
        for backend in self.all_backends():
            if backend.name == name:
                return backend
        raise FirewallError(errors.UNKNOWN_ERROR,
                            "'%s' backend does not exist" % name)

def get_backend_by_ipv(self, ipv):
        if self.nftables_enabled:
            return self.nftables_backend
        if ipv == "ipv4" and self.ip4tables_enabled:
            return self.ip4tables_backend
        elif ipv == "ipv6" and self.ip6tables_enabled:
            return self.ip6tables_backend
        elif ipv == "eb" and self.ebtables_enabled:
            return self.ebtables_backend
        raise FirewallError(errors.INVALID_IPV,
                            "'%s' is not a valid backend or is unavailable" % ipv)

def get_direct_backend_by_ipv(self, ipv):
        if ipv == "ipv4" and self.ip4tables_enabled:
            return self.ip4tables_backend
        elif ipv == "ipv6" and self.ip6tables_enabled:
            return self.ip6tables_backend
        elif ipv == "eb" and self.ebtables_enabled:
            return self.ebtables_backend
        raise FirewallError(errors.INVALID_IPV,
                            "'%s' is not a valid backend or is unavailable" % ipv)

def is_backend_enabled(self, name):
        if name == "ip4tables":
            return self.ip4tables_enabled
        elif name == "ip6tables":
            return self.ip6tables_enabled
        elif name == "ebtables":
            return self.ebtables_enabled
        elif name == "nftables":
            return self.nftables_enabled
        return False

def is_ipv_enabled(self, ipv):
        if self.nftables_enabled:
            return True
        if ipv == "ipv4":
            return self.ip4tables_enabled
        elif ipv == "ipv6":
            return self.ip6tables_enabled
        elif ipv == "eb":
            return self.ebtables_enabled
        return False

def enabled_backends(self):
        backends = []
        if self.nftables_enabled:
            backends.append(self.nftables_backend)
        else:
            if self.ip4tables_enabled:
                backends.append(self.ip4tables_backend)
            if self.ip6tables_enabled:
                backends.append(self.ip6tables_backend)
            if self.ebtables_enabled:
                backends.append(self.ebtables_backend)
        return backends

def all_backends(self):
        backends = []
        if self.ip4tables_enabled:
            backends.append(self.ip4tables_backend)
        if self.ip6tables_enabled:
            backends.append(self.ip6tables_backend)
        if self.ebtables_enabled:
            backends.append(self.ebtables_backend)
        if self.nftables_enabled:
            backends.append(self.nftables_backend)
        return backends

def apply_default_tables(self, use_transaction=None):
        if use_transaction is None:
            transaction = FirewallTransaction(self)
        else:
            transaction = use_transaction

for backend in self.enabled_backends():
            transaction.add_rules(backend, backend.build_default_tables())