freeipa/ipaserver/install/plugins/dns.py
Martin Basti af6aece39b Fix zone find during forwardzone upgrade
https://fedorahosted.org/freeipa/ticket/4818

Reviewed-By: Petr Spacek <pspacek@redhat.com>
2015-01-09 13:30:37 +01:00

361 lines
15 KiB
Python

# Authors:
# Martin Kosek <mkosek@redhat.com>
#
# Copyright (C) 2012 Red Hat
# see file 'COPYING' for use and warranty information
#
# 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 3 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/>.
import ldap as _ldap
import re
import traceback
import time
from ldif import LDIFWriter
from ipaserver.install.plugins import MIDDLE, LAST
from ipaserver.install.plugins.baseupdate import (PostUpdate, PreUpdate,
PreSchemaUpdate)
from ipaserver.install import sysupgrade
from ipalib import api, errors, util
from ipapython.dn import DN
from ipalib.plugins.dns import dns_container_exists
from ipapython.ipa_log_manager import *
class update_dnszones(PostUpdate):
"""
Update all zones to meet requirements in the new FreeIPA versions
1) AllowQuery and AllowTransfer
Set AllowQuery and AllowTransfer ACLs in all zones that may be configured
in an upgraded FreeIPA instance.
Upgrading to new version of bind-dyndb-ldap and having these ACLs empty
would result in a leak of potentially sensitive DNS information as
zone transfers are enabled for all hosts if not disabled in named.conf
or LDAP.
This plugin disables the zone transfer by default so that it needs to be
explicitly enabled by FreeIPA Administrator.
2) Update policy
SSH public key support includes a feature to automatically add/update
client SSH fingerprints in SSHFP records. However, the update won't
work for zones created before this support was added as they don't allow
clients to update SSHFP records in their update policies.
This module extends the original policy to allow the SSHFP updates.
"""
order=MIDDLE
def execute(self, **options):
ldap = self.obj.backend
if not dns_container_exists(ldap):
return (False, False, [])
try:
zones = api.Command.dnszone_find(all=True)['result']
except errors.NotFound:
self.log.info('No DNS zone to update found')
return (False, False, [])
for zone in zones:
update = {}
if not zone.get('idnsallowquery'):
# allow query from any client by default
update['idnsallowquery'] = u'any;'
if not zone.get('idnsallowtransfer'):
# do not open zone transfers by default
update['idnsallowtransfer'] = u'none;'
old_policy = util.get_dns_forward_zone_update_policy(api.env.realm, ('A', 'AAAA'))
if zone.get('idnsupdatepolicy', [''])[0] == old_policy:
update['idnsupdatepolicy'] = util.get_dns_forward_zone_update_policy(\
api.env.realm)
if update:
# FIXME: https://fedorahosted.org/freeipa/ticket/4722
api.Command.dnszone_mod(zone[u'idnsname'][0].make_absolute(),
**update)
return (False, False, [])
api.register(update_dnszones)
class update_dns_limits(PostUpdate):
"""
bind-dyndb-ldap persistent search queries LDAP for all DNS records.
The LDAP connection must have no size or time limits to work
properly. This plugin updates limits of the existing DNS service
principal to match there requirements.
"""
limit_attributes = ['nsTimeLimit', 'nsSizeLimit', 'nsIdleTimeout', 'nsLookThroughLimit']
limit_value = '-1'
def execute(self, **options):
ldap = self.obj.backend
if not dns_container_exists(ldap):
return (False, False, [])
dns_principal = 'DNS/%s@%s' % (self.env.host, self.env.realm)
dns_service_dn = DN(('krbprincipalname', dns_principal),
self.env.container_service,
self.env.basedn)
try:
entry = ldap.get_entry(dns_service_dn, self.limit_attributes)
except errors.NotFound:
# this host may not have DNS service set
root_logger.debug("DNS: service %s not found, no need to update limits" % dns_service_dn)
return (False, False, [])
if all(entry.get(limit.lower(), [None])[0] == self.limit_value for limit in self.limit_attributes):
root_logger.debug("DNS: limits for service %s already set" % dns_service_dn)
# service is already updated
return (False, False, [])
limit_updates = []
for limit in self.limit_attributes:
limit_updates.append('only:%s:%s' % (limit, self.limit_value))
dnsupdates = {}
dnsupdates[dns_service_dn] = {'dn': dns_service_dn,
'updates': limit_updates}
root_logger.debug("DNS: limits for service %s will be updated" % dns_service_dn)
return (False, True, [dnsupdates])
api.register(update_dns_limits)
class update_master_to_dnsforwardzones(PostUpdate):
"""
Update all zones to meet requirements in the new FreeIPA versions
All masters zones with specified forwarders, and forward-policy different
than none, will be tranformed to forward zones.
Original masters zone will be backed up to ldif file.
This should be applied only once, and only if original version was lower than 4.0
"""
order = LAST
backup_dir = u'/var/lib/ipa/backup/'
backup_filename = u'dns-forward-zones-backup-%Y-%m-%d-%H-%M-%S.ldif'
backup_path = u'%s%s' % (backup_dir, backup_filename)
def execute(self, **options):
ldap = self.obj.backend
# check LDAP if forwardzones already uses new semantics
dns_container_dn = DN(api.env.container_dns, api.env.basedn)
try:
container_entry = ldap.get_entry(dns_container_dn)
except errors.NotFound:
# DNS container not found, nothing to upgrade
return (False, False, [])
for config_option in container_entry.get("ipaConfigString", []):
matched = re.match("^DNSVersion\s+(?P<version>\d+)$",
config_option, flags=re.I)
if matched and int(matched.group("version")) >= 1:
# forwardzones already uses new semantics,
# no upgrade is required
return (False, False, [])
self.log.info('Updating forward zones')
# update the DNSVersion, following upgrade can be executed only once
container_entry.setdefault(
'ipaConfigString', []).append(u"DNSVersion 1")
ldap.update_entry(container_entry)
# Updater in IPA version from 4.0 to 4.1.2 doesn't work well, this
# should detect if update in past has been executed, and set proper
# DNSVersion into LDAP
try:
fwzones = api.Command.dnsforwardzone_find()['result']
except errors.NotFound:
# No forwardzones found, update probably has not been executed yet
pass
else:
if fwzones:
# fwzones exist, do not execute upgrade again
return (False, False, [])
zones = []
try:
# raw values are required to store into ldif
zones = api.Command.dnszone_find(all=True,
raw=True,
sizelimit=0)['result']
except errors.NotFound:
pass
if not zones:
self.log.info('No DNS zone to update found')
return (False, False, [])
zones_to_transform = []
for zone in zones:
if (
zone.get('idnsforwardpolicy', [u'first'])[0] == u'none' or
zone.get('idnsforwarders', []) == []
):
continue # don't update zone
zones_to_transform.append(zone)
if zones_to_transform:
# add time to filename
self.backup_path = time.strftime(self.backup_path)
# DNs of privileges which contain dns managed permissions
privileges_to_ldif = set() # store priviledges only once
zone_to_privileges = {} # zone: [privileges cn]
self.log.info('Zones with specified forwarders with policy different'
' than none will be transformed to forward zones.')
self.log.info('Original zones will be saved in LDIF format in '
'%s file' % self.backup_path)
try:
with open(self.backup_path, 'w') as f:
writer = LDIFWriter(f)
for zone in zones_to_transform:
# save backup to ldif
try:
dn = str(zone['dn'])
del zone['dn'] # dn shouldn't be as attribute in ldif
writer.unparse(dn, zone)
if 'managedBy' in zone:
entry = ldap.get_entry(DN(zone['managedBy'][0]))
for privilege_member_dn in entry.get('member', []):
privileges_to_ldif.add(privilege_member_dn)
writer.unparse(str(entry.dn), dict(entry.raw))
# privileges where permission is used
if entry.get('member'):
zone_to_privileges[zone['idnsname'][0]] = entry['member']
# raw values are required to store into ldif
records = api.Command['dnsrecord_find'](
zone['idnsname'][0],
all=True,
raw=True,
sizelimit=0)['result']
for record in records:
if record['idnsname'][0] == u'@':
# zone record was saved before
continue
dn = str(record['dn'])
del record['dn']
writer.unparse(dn, record)
except Exception, e:
self.log.error('Unable to backup zone %s' %
zone['idnsname'][0])
self.log.error(traceback.format_exc())
return (False, False, [])
for privilege_dn in privileges_to_ldif:
try:
entry = ldap.get_entry(privilege_dn)
writer.unparse(str(entry.dn), dict(entry.raw))
except Exception, e:
self.log.error('Unable to backup privilege %s' %
privilege_dn)
self.log.error(traceback.format_exc())
return (False, False, [])
f.close()
except Exception:
self.log.error('Unable to create backup file')
self.log.error(traceback.format_exc())
return (False, False, [])
# update
for zone in zones_to_transform:
# delete master zone
try:
api.Command['dnszone_del'](zone['idnsname'])
except Exception, e:
self.log.error('Transform to forwardzone terminated: '
'removing zone %s failed (%s)' % (
zone['idnsname'][0], e)
)
self.log.error(traceback.format_exc())
continue
# create forward zone
try:
kw = {
'idnsforwarders': zone.get('idnsforwarders', []),
'idnsforwardpolicy': zone.get('idnsforwardpolicy', [u'first'])[0]
}
api.Command['dnsforwardzone_add'](zone['idnsname'][0], **kw)
except Exception, e:
self.log.error('Transform to forwardzone terminated: creating '
'forwardzone %s failed' %
zone['idnsname'][0])
self.log.error(traceback.format_exc())
continue
# create permission if original zone has one
if 'managedBy' in zone:
try:
perm_name = api.Command['dnsforwardzone_add_permission'](
zone['idnsname'][0])['value']
except Exception, e:
self.log.error('Transform to forwardzone terminated: '
'Adding managed by permission to forward zone'
' %s failed' % zone['idnsname'])
self.log.error(traceback.format_exc())
self.log.info('Zone %s was transformed to forward zone '
' without managed permissions',
zone['idnsname'][0])
continue
else:
if zone['idnsname'][0] in zone_to_privileges:
privileges = [
dn[0].value for dn in zone_to_privileges[zone['idnsname'][0]]
]
try:
api.Command['permission_add_member'](perm_name,
privilege=privileges)
except Exception, e:
self.log.error('Unable to restore privileges for '
'permission %s, for zone %s'
% (perm_name, zone['idnsname']))
self.log.error(traceback.format_exc())
self.log.info('Zone %s was transformed to forward zone'
' without restored privileges',
zone['idnsname'][0])
continue
self.log.info('Zone %s was sucessfully transformed to forward zone',
zone['idnsname'][0])
return (False, False, [])
api.register(update_master_to_dnsforwardzones)