Commit d72c6520 authored by Graham Hayes's avatar Graham Hayes

Ensure we do not pass invalid data for A records

DNSPython does not allow IPs to have leading zeros
for A records [1] and eventlet agrees [2], so we should
ensure we do not create a situation where a project can
DOS itself.

This patch uses the DNSPython method to ensure it is kept in sync

1 - https://github.com/rthalley/dnspython/blob/v1.15.0/dns/ipv4.py#L52-L54
2 - https://github.com/eventlet/eventlet/blob/v0.20.0/eventlet/support/dns/ipv4.py#L52-L54

Partial-Bug: 1760833
Change-Id: I975b18d390647de9fe11c105cd421b761f88be6c
parent 7a2adab5
#!/usr/bin/env python
# Copyright (C) 2018 Verizon
#
# Author: Graham Hayes <gr@ham.ie>
#
# 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.
import sys
import argparse
import logging
import dns.exception
from dns.ipv4 import inet_aton
import netaddr
from designateclient.v2 import client
from designateclient import shell
from keystoneauth1.identity import generic
from keystoneauth1 import session as keystone_session
auth = generic.Password(
auth_url=shell.env('OS_AUTH_URL'),
username=shell.env('OS_USERNAME'),
password=shell.env('OS_PASSWORD'),
project_name=shell.env('OS_PROJECT_NAME'),
project_domain_id=shell.env('OS_PROJECT_DOMAIN_ID'),
user_domain_id=shell.env('OS_USER_DOMAIN_ID'))
session = keystone_session.Session(auth=auth)
client = client.Client(session=session)
logging.basicConfig()
LOG = logging.getLogger('fixleadingzeros')
def find_bad_recordsets():
bad_recordsets = {}
LOG.debug("Looking for all A recordsets")
recordsets = client.recordsets.list_all_zones(criterion={'type': 'A', })
LOG.debug("Found %d A recordsets", len(recordsets))
LOG.debug("Filtering recordsets")
for recordset in recordsets:
for record in recordset['records']:
try:
inet_aton(record)
except dns.exception.SyntaxError:
bad_recordsets[recordset['id']] = recordset
LOG.debug("Found %d A invaild recordsets", len(bad_recordsets))
return bad_recordsets
def show_recordsets(recordsets):
for rs in recordsets:
LOG.info(
("%(name)s - %(records)s - Zone ID: %(zone_id)s - "
"Project ID: %(project_id)s ") % recordsets[rs])
def fix_bad_recordsets(bad_recordsets):
LOG.debug("Removing leading zeros in IPv4 addresses")
for rs in bad_recordsets:
new_records = []
for ip in bad_recordsets[rs]['records']:
new_records.append(
str(netaddr.IPAddress(ip, flags=netaddr.ZEROFILL).ipv4())
)
bad_recordsets[rs]['records'] = new_records
return bad_recordsets
def update_recordsets(recordsets):
LOG.info("Updating recordsets")
for rs in recordsets:
LOG.debug(("Updating %(name)s - %(records)s - Zone ID: %(zone_id)s - "
"Project ID: %(project_id)s ") % recordsets[rs])
client.recordsets.update(
recordsets[rs]['zone_id'],
recordsets[rs]['id'],
{'records': recordsets[rs]['records']}
)
def main():
parser = argparse.ArgumentParser(
description='Fix any recordsets that have leading zeros in A records')
parser.add_argument('-v', '--verbose', action='store_true',
help='verbose output')
parser.add_argument('-d', '--dry-run', action='store_true',
help='do not modify records, just log bad records')
parser.add_argument('-a', '--all-projects', action='store_true',
help="Run on all projects")
args = parser.parse_args()
if args.verbose:
LOG.setLevel(logging.DEBUG)
else:
LOG.setLevel(logging.INFO)
if args.all_projects:
client.session.all_projects = True
bad_recordsets = find_bad_recordsets()
LOG.info("Bad recordsets")
show_recordsets(bad_recordsets)
fixed_recordsets = fix_bad_recordsets(bad_recordsets)
LOG.info("Fixed recordsets")
show_recordsets(fixed_recordsets)
if not args.dry_run:
update_recordsets(fixed_recordsets)
if __name__ == '__main__':
sys.exit(main())
......@@ -12,7 +12,8 @@
# 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 dns import ipv4
import dns.exception
import re
import uuid
......@@ -141,6 +142,11 @@ class ObjectField(ovoo_fields.ObjectField):
class IPV4AddressField(ovoo_fields.IPV4AddressField):
def coerce(self, obj, attr, value):
try:
# make sure that DNS Python agrees that it is a valid IP address
ipv4.inet_aton(str(value))
except dns.exception.SyntaxError:
raise ValueError()
value = super(IPV4AddressField, self).coerce(obj, attr, value)
# we use this field as a string, not need a netaddr.IPAdress
# as oslo.versionedobjects is using
......
# Copyright 2018 Verizon Wireless
#
# Author: Graham Hayes <gr@ham.ie>
#
# 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 oslo_log import log as logging
import oslotest.base
import testtools
from designate import exceptions
from designate import objects
LOG = logging.getLogger(__name__)
class RRDataATest(oslotest.base.BaseTestCase):
def test_reject_leading_zeros(self):
record = objects.A(data='10.0.001.1')
with testtools.ExpectedException(exceptions.InvalidObject):
record.validate()
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