vmware-nsx/vmware_nsx/services/fwaas/nsx_v/edge_fwaas_driver.py
Adit Sarfaty 80d83e2fce NSX|V: Fix FWaaS exceptions
Commit I6faf26d263788d21da078e570487ee4876d04efd moved the fwaas
exceptions to a new file

Change-Id: I1684605a16b7dfb565cbba373397181e5ebefbbd
2017-06-06 11:49:32 +03:00

283 lines
11 KiB
Python

# Copyright 2017 VMware, 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.
from neutron_lib import context as n_context
from neutron_lib.plugins import directory
from oslo_log import helpers as log_helpers
from oslo_log import log as logging
from neutron_fwaas.common import exceptions
from neutron_fwaas.services.firewall.drivers import fwaas_base
from vmware_nsx.common import locking
from vmware_nsx.plugins.nsx_v.vshield.common import (
exceptions as vcns_exc)
from vmware_nsx.plugins.nsx_v.vshield import edge_firewall_driver
from vmware_nsx.plugins.nsx_v.vshield import edge_utils
from vmware_nsx.plugins.nsx_v.vshield import vcns_driver
LOG = logging.getLogger(__name__)
FWAAS_DRIVER_NAME = 'Fwaas NSX-V driver'
RULE_NAME_PREFIX = 'Fwaas-'
class EdgeFwaasDriver(fwaas_base.FwaasDriverBase):
"""NSX-V driver for Firewall As A Service - V1."""
@property
def edge_manager(self):
return directory.get_plugin().edge_manager
def __init__(self):
LOG.debug("Loading FWaaS NsxVDriver.")
super(EdgeFwaasDriver, self).__init__()
self._nsxv = vcns_driver.VcnsDriver(None)
def should_apply_firewall_to_router(self, router_data):
"""Return True if the firewall rules should be added the router
Return False in those cases:
- router without an external gateway (rule may be added later when
there is a gateway)
Raise an exception if the router is unsupported:
- shared router (not supported)
- md proxy router (not supported)
"""
if (not router_data.get('distributed') and
router_data.get('router_type') == 'shared'):
LOG.error("Cannot apply firewall to shared router %s",
router_data['id'])
raise exceptions.FirewallInternalDriverError(
driver=FWAAS_DRIVER_NAME)
if router_data.get('name', '').startswith('metadata_proxy_router'):
LOG.error("Cannot apply firewall to the metadata proxy router %s",
router_data['id'])
raise exceptions.FirewallInternalDriverError(
driver=FWAAS_DRIVER_NAME)
if not router_data.get('external_gateway_info'):
LOG.info("Cannot apply firewall to router %s with no gateway",
router_data['id'])
return False
return True
def _get_routers_edges(self, context, apply_list):
# Get edges for all the routers in the apply list.
# note that shared routers are currently not supported
edge_manager = self.edge_manager
edges = []
for router_info in apply_list:
# No FWaaS rules needed if there is no external gateway
if not self.should_apply_firewall_to_router(router_info.router):
continue
lookup_id = None
router_id = router_info.router_id
if router_info.router.get('distributed'):
# Distributed router
# we need the plr edge id
lookup_id = edge_manager.get_plr_by_tlr_id(
context, router_id)
else:
# Exclusive router
lookup_id = router_id
if lookup_id:
# look for the edge id in the DB
edge_id = edge_utils.get_router_edge_id(context, lookup_id)
if edge_id:
edges.append(edge_id)
return edges
def _translate_rules(self, fwaas_rules):
translated_rules = []
for rule in fwaas_rules:
if not rule['enabled']:
# skip disabled rules
continue
# Make sure the rule has a name, and it starts with the prefix
# (backend max name length is 30)
if rule.get('name'):
rule['name'] = RULE_NAME_PREFIX + rule['name']
else:
rule['name'] = RULE_NAME_PREFIX + rule['id']
rule['name'] = rule['name'][:30]
# source & destination should be lists
if rule.get('destination_ip_address'):
rule['destination_ip_address'] = [
rule['destination_ip_address']]
if rule.get('source_ip_address'):
rule['source_ip_address'] = [rule['source_ip_address']]
translated_rules.append(rule)
return translated_rules
def _is_allow_external_rule(self, rule):
rule_name = rule.get('name', '')
if rule_name == edge_firewall_driver.FWAAS_ALLOW_EXT_RULE_NAME:
return True
# For older routers, the allow-external rule didn't have a name
# TODO(asarfaty): delete this in the future
if (not rule_name and
rule.get('action') == edge_firewall_driver.FWAAS_ALLOW and
rule.get('destination_vnic_groups', []) == ['external']):
return True
return False
def _get_other_backend_rules(self, context, edge_id):
"""Get a list of current backend rules from other applications
Those rules should stay on the backend firewall, when updating the
FWaaS rules.
Return it as 2 separate lists of rules, which should go before/after
the fwaas rules.
"""
try:
backend_fw = self._nsxv.get_firewall(context, edge_id)
backend_rules = backend_fw['firewall_rule_list']
except vcns_exc.VcnsApiException:
# Need to create a new one
backend_rules = []
# remove old FWaaS rules from the rules list.
# also delete the allow-external rule, if it is there.
# If necessary - we will add it again later
before_rules = []
after_rules = []
go_after = False
for rule_item in backend_rules:
rule = rule_item['firewall_rule']
rule_name = rule.get('name', '')
fwaas_rule = rule_name.startswith(RULE_NAME_PREFIX)
if fwaas_rule:
# reached the fwaas part, the rest of the rules should be
# in the 'after' list
go_after = True
if (rule_name == edge_firewall_driver.DNAT_RULE_NAME or
rule_name == edge_firewall_driver.NO_SNAT_RULE_NAME):
# passed the fwaas part, the rest of the rules should be
# in the 'after' list
go_after = True
if (not fwaas_rule and
not self._is_allow_external_rule(rule)):
if go_after:
after_rules.append(rule)
else:
before_rules.append(rule)
return before_rules, after_rules
def _set_rules_on_edge(self, context, edge_id, fw_id, translated_rules,
allow_external=False):
"""delete old FWaaS rules from the Edge, and add new ones
Note that the edge might have other FW rules like NAT or LBaas
that should remain there.
allow_external is usually False because it shouldn't exist with a
firewall. It should only be True when the firewall is being deleted.
"""
# Get the existing backend rules which do not belong to FWaaS
backend_rules, after_rules = self._get_other_backend_rules(
context, edge_id)
# add new FWaaS rules at the correct location by their original order
backend_rules.extend(translated_rules)
backend_rules.extend(after_rules)
# update the backend
try:
with locking.LockManager.get_lock(str(edge_id)):
self._nsxv.update_firewall(
edge_id,
{'firewall_rule_list': backend_rules},
context,
allow_external=allow_external)
except Exception as e:
# catch known library exceptions and raise Fwaas generic exception
LOG.error("Failed to update backend firewall %(fw)s: "
"%(e)s", {'e': e, 'fw': fw_id})
raise exceptions.FirewallInternalDriverError(
driver=FWAAS_DRIVER_NAME)
def _create_or_update_firewall(self, agent_mode, apply_list, firewall):
# admin state down means default block rule firewall
if not firewall['admin_state_up']:
self.apply_default_policy(agent_mode, apply_list, firewall)
return
context = n_context.get_admin_context()
# Find out the relevant edges
router_edges = self._get_routers_edges(context, apply_list)
if not router_edges:
LOG.warning("Cannot apply the firewall to any of the routers %s",
apply_list)
return
rules = self._translate_rules(firewall['firewall_rule_list'])
# update each edge
for edge_id in router_edges:
self._set_rules_on_edge(
context, edge_id, firewall['id'], rules)
@log_helpers.log_method_call
def create_firewall(self, agent_mode, apply_list, firewall):
"""Create the Firewall with a given policy. """
self._create_or_update_firewall(agent_mode, apply_list, firewall)
@log_helpers.log_method_call
def update_firewall(self, agent_mode, apply_list, firewall):
"""Remove previous policy and apply the new policy."""
self._create_or_update_firewall(agent_mode, apply_list, firewall)
def _delete_firewall_or_set_default_policy(self, apply_list, firewall,
allow_external):
context = n_context.get_admin_context()
router_edges = self._get_routers_edges(context, apply_list)
if router_edges:
for edge_id in router_edges:
self._set_rules_on_edge(context, edge_id, firewall['id'], [],
allow_external=allow_external)
@log_helpers.log_method_call
def delete_firewall(self, agent_mode, apply_list, firewall):
"""Delete firewall.
Removes rules created by this instance from the backend firewall
And add the default allow-external rule.
"""
self._delete_firewall_or_set_default_policy(apply_list, firewall,
allow_external=True)
@log_helpers.log_method_call
def apply_default_policy(self, agent_mode, apply_list, firewall):
"""Apply the default policy (deny all).
The backend firewall always has this policy (=deny all) as default,
so we only need to delete the current rules.
"""
self._delete_firewall_or_set_default_policy(apply_list, firewall,
allow_external=False)
def get_firewall_translated_rules(self, firewall):
if firewall['admin_state_up']:
return self._translate_rules(firewall['firewall_rule_list'])
return []