neutron/neutron/services/firewall/drivers/linux/iptables_fwaas.py

276 lines
12 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# Copyright 2013 Dell Inc.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
#
# @author: Rajesh Mohan, Rajesh_Mohan3@Dell.com, DELL Inc.
from neutron.agent.linux import iptables_manager
from neutron.extensions import firewall as fw_ext
from neutron.openstack.common import log as logging
from neutron.services.firewall.drivers import fwaas_base
LOG = logging.getLogger(__name__)
FWAAS_DRIVER_NAME = 'Fwaas iptables driver'
FWAAS_DEFAULT_CHAIN = 'fwaas-default-policy'
INGRESS_DIRECTION = 'ingress'
EGRESS_DIRECTION = 'egress'
CHAIN_NAME_PREFIX = {INGRESS_DIRECTION: 'i',
EGRESS_DIRECTION: 'o'}
""" Firewall rules are applied on internal-interfaces of Neutron router.
The packets ingressing tenant's network will be on the output
direction on internal-interfaces.
"""
IPTABLES_DIR = {INGRESS_DIRECTION: '-o',
EGRESS_DIRECTION: '-i'}
IPV4 = 'ipv4'
IPV6 = 'ipv6'
IP_VER_TAG = {IPV4: 'v4',
IPV6: 'v6'}
class IptablesFwaasDriver(fwaas_base.FwaasDriverBase):
"""IPTables driver for Firewall As A Service."""
def __init__(self):
LOG.debug(_("Initializing fwaas iptables driver"))
def create_firewall(self, apply_list, firewall):
LOG.debug(_('Creating firewall %(fw_id)s for tenant %(tid)s)'),
{'fw_id': firewall['id'], 'tid': firewall['tenant_id']})
try:
if firewall['admin_state_up']:
self._setup_firewall(apply_list, firewall)
else:
self.apply_default_policy(apply_list, firewall)
except (LookupError, RuntimeError):
# catch known library exceptions and raise Fwaas generic exception
LOG.exception(_("Failed to create firewall: %s"), firewall['id'])
raise fw_ext.FirewallInternalDriverError(driver=FWAAS_DRIVER_NAME)
def delete_firewall(self, apply_list, firewall):
LOG.debug(_('Deleting firewall %(fw_id)s for tenant %(tid)s)'),
{'fw_id': firewall['id'], 'tid': firewall['tenant_id']})
fwid = firewall['id']
try:
for router_info in apply_list:
ipt_mgr = router_info.iptables_manager
self._remove_chains(fwid, ipt_mgr)
self._remove_default_chains(ipt_mgr)
# apply the changes immediately (no defer in firewall path)
ipt_mgr.defer_apply_off()
except (LookupError, RuntimeError):
# catch known library exceptions and raise Fwaas generic exception
LOG.exception(_("Failed to delete firewall: %s"), fwid)
raise fw_ext.FirewallInternalDriverError(driver=FWAAS_DRIVER_NAME)
def update_firewall(self, apply_list, firewall):
LOG.debug(_('Updating firewall %(fw_id)s for tenant %(tid)s)'),
{'fw_id': firewall['id'], 'tid': firewall['tenant_id']})
try:
if firewall['admin_state_up']:
self._setup_firewall(apply_list, firewall)
else:
self.apply_default_policy(apply_list, firewall)
except (LookupError, RuntimeError):
# catch known library exceptions and raise Fwaas generic exception
LOG.exception(_("Failed to update firewall: %s"), firewall['id'])
raise fw_ext.FirewallInternalDriverError(driver=FWAAS_DRIVER_NAME)
def apply_default_policy(self, apply_list, firewall):
LOG.debug(_('Applying firewall %(fw_id)s for tenant %(tid)s)'),
{'fw_id': firewall['id'], 'tid': firewall['tenant_id']})
fwid = firewall['id']
try:
for router_info in apply_list:
ipt_mgr = router_info.iptables_manager
# the following only updates local memory; no hole in FW
self._remove_chains(fwid, ipt_mgr)
self._remove_default_chains(ipt_mgr)
# create default 'DROP ALL' policy chain
self._add_default_policy_chain_v4v6(ipt_mgr)
self._enable_policy_chain(fwid, ipt_mgr)
# apply the changes immediately (no defer in firewall path)
ipt_mgr.defer_apply_off()
except (LookupError, RuntimeError):
# catch known library exceptions and raise Fwaas generic exception
LOG.exception(_("Failed to apply default policy on firewall: %s"),
fwid)
raise fw_ext.FirewallInternalDriverError(driver=FWAAS_DRIVER_NAME)
def _setup_firewall(self, apply_list, firewall):
fwid = firewall['id']
for router_info in apply_list:
ipt_mgr = router_info.iptables_manager
# the following only updates local memory; no hole in FW
self._remove_chains(fwid, ipt_mgr)
self._remove_default_chains(ipt_mgr)
# create default 'DROP ALL' policy chain
self._add_default_policy_chain_v4v6(ipt_mgr)
#create chain based on configured policy
self._setup_chains(firewall, ipt_mgr)
# apply the changes immediately (no defer in firewall path)
ipt_mgr.defer_apply_off()
def _get_chain_name(self, fwid, ver, direction):
return '%s%s%s' % (CHAIN_NAME_PREFIX[direction],
IP_VER_TAG[ver],
fwid)
def _setup_chains(self, firewall, ipt_mgr):
"""Create Fwaas chain using the rules in the policy
"""
fw_rules_list = firewall['firewall_rule_list']
fwid = firewall['id']
#default rules for invalid packets and established sessions
invalid_rule = self._drop_invalid_packets_rule()
est_rule = self._allow_established_rule()
for ver in [IPV4, IPV6]:
if ver == IPV4:
table = ipt_mgr.ipv4['filter']
else:
table = ipt_mgr.ipv6['filter']
ichain_name = self._get_chain_name(fwid, ver, INGRESS_DIRECTION)
ochain_name = self._get_chain_name(fwid, ver, EGRESS_DIRECTION)
for name in [ichain_name, ochain_name]:
table.add_chain(name)
table.add_rule(name, invalid_rule)
table.add_rule(name, est_rule)
for rule in fw_rules_list:
if not rule['enabled']:
continue
iptbl_rule = self._convert_fwaas_to_iptables_rule(rule)
if rule['ip_version'] == 4:
ver = IPV4
table = ipt_mgr.ipv4['filter']
else:
ver = IPV6
table = ipt_mgr.ipv6['filter']
ichain_name = self._get_chain_name(fwid, ver, INGRESS_DIRECTION)
ochain_name = self._get_chain_name(fwid, ver, EGRESS_DIRECTION)
table.add_rule(ichain_name, iptbl_rule)
table.add_rule(ochain_name, iptbl_rule)
self._enable_policy_chain(fwid, ipt_mgr)
def _remove_default_chains(self, nsid):
"""Remove fwaas default policy chain."""
self._remove_chain_by_name(IPV4, FWAAS_DEFAULT_CHAIN, nsid)
self._remove_chain_by_name(IPV6, FWAAS_DEFAULT_CHAIN, nsid)
def _remove_chains(self, fwid, ipt_mgr):
"""Remove fwaas policy chain."""
for ver in [IPV4, IPV6]:
for direction in [INGRESS_DIRECTION, EGRESS_DIRECTION]:
chain_name = self._get_chain_name(fwid, ver, direction)
self._remove_chain_by_name(ver, chain_name, ipt_mgr)
def _add_default_policy_chain_v4v6(self, ipt_mgr):
ipt_mgr.ipv4['filter'].add_chain(FWAAS_DEFAULT_CHAIN)
ipt_mgr.ipv4['filter'].add_rule(FWAAS_DEFAULT_CHAIN, '-j DROP')
ipt_mgr.ipv6['filter'].add_chain(FWAAS_DEFAULT_CHAIN)
ipt_mgr.ipv6['filter'].add_rule(FWAAS_DEFAULT_CHAIN, '-j DROP')
def _remove_chain_by_name(self, ver, chain_name, ipt_mgr):
if ver == IPV4:
ipt_mgr.ipv4['filter'].ensure_remove_chain(chain_name)
else:
ipt_mgr.ipv6['filter'].ensure_remove_chain(chain_name)
def _add_rules_to_chain(self, ipt_mgr, ver, chain_name, rules):
if ver == IPV4:
table = ipt_mgr.ipv4['filter']
else:
table = ipt_mgr.ipv6['filter']
for rule in rules:
table.add_rule(chain_name, rule)
def _enable_policy_chain(self, fwid, ipt_mgr):
bname = iptables_manager.binary_name
for (ver, tbl) in [(IPV4, ipt_mgr.ipv4['filter']),
(IPV6, ipt_mgr.ipv6['filter'])]:
for direction in [INGRESS_DIRECTION, EGRESS_DIRECTION]:
chain_name = self._get_chain_name(fwid, ver, direction)
chain_name = iptables_manager.get_chain_name(chain_name)
if chain_name in tbl.chains:
jump_rule = ['%s qr-+ -j %s-%s' % (IPTABLES_DIR[direction],
bname, chain_name)]
self._add_rules_to_chain(ipt_mgr, ver, 'FORWARD',
jump_rule)
#jump to DROP_ALL policy
chain_name = iptables_manager.get_chain_name(FWAAS_DEFAULT_CHAIN)
jump_rule = ['-o qr-+ -j %s-%s' % (bname, chain_name)]
self._add_rules_to_chain(ipt_mgr, IPV4, 'FORWARD', jump_rule)
self._add_rules_to_chain(ipt_mgr, IPV6, 'FORWARD', jump_rule)
#jump to DROP_ALL policy
chain_name = iptables_manager.get_chain_name(FWAAS_DEFAULT_CHAIN)
jump_rule = ['-i qr-+ -j %s-%s' % (bname, chain_name)]
self._add_rules_to_chain(ipt_mgr, IPV4, 'FORWARD', jump_rule)
self._add_rules_to_chain(ipt_mgr, IPV6, 'FORWARD', jump_rule)
def _convert_fwaas_to_iptables_rule(self, rule):
action = rule.get('action') == 'allow' and 'ACCEPT' or 'DROP'
args = [self._protocol_arg(rule.get('protocol')),
self._port_arg('dport',
rule.get('protocol'),
rule.get('destination_port')),
self._port_arg('sport',
rule.get('protocol'),
rule.get('source_port')),
self._ip_prefix_arg('s', rule.get('source_ip_address')),
self._ip_prefix_arg('d', rule.get('destination_ip_address')),
self._action_arg(action)]
iptables_rule = ' '.join(args)
return iptables_rule
def _drop_invalid_packets_rule(self):
return '-m state --state INVALID -j DROP'
def _allow_established_rule(self):
return '-m state --state ESTABLISHED,RELATED -j ACCEPT'
def _action_arg(self, action):
if action:
return '-j %s' % action
return ''
def _protocol_arg(self, protocol):
if protocol:
return '-p %s' % protocol
return ''
def _port_arg(self, direction, protocol, port):
if not (protocol in ['udp', 'tcp'] and port):
return ''
return '--%s %s' % (direction, port)
def _ip_prefix_arg(self, direction, ip_prefix):
if ip_prefix:
return '-%s %s' % (direction, ip_prefix)
return ''