def __do_update(self):
'''Scan, check, and execute the Update section in the
DDNS Update message.
Returns an Rcode to signal the result (NOERROR upon success,
any error result otherwise).
'''
# prescan
prescan_result = self.__do_prescan()
if prescan_result != Rcode.NOERROR:
return prescan_result
# update
try:
# Do special handling for SOA first
self.__update_soa()
# Algorithm from RFC2136 Section 3.4
# Note that this works on full rrsets, not individual RRs.
# Some checks might be easier with individual RRs, but only if we
# would use the ZoneUpdater directly (so we can query the
# 'zone-as-it-would-be-so-far'. However, due to the current use
# of the Diff class, this is not the case, and therefore it
# is easier to work with full rrsets for the most parts
# (less lookups needed; conversion to individual rrs is
# the same effort whether it is done here or in the several
# do_update statements)
for rrset in self.__message.get_section(SECTION_UPDATE):
if rrset.get_class() == self.__zclass:
self.__do_update_add_rrs_to_rrset(rrset)
elif rrset.get_class() == RRClass.ANY:
if rrset.get_type() == RRType.ANY:
self.__do_update_delete_name(rrset)
else:
self.__do_update_delete_rrset(rrset)
elif rrset.get_class() == RRClass.NONE:
self.__do_update_delete_rrs_from_rrset(rrset)
if not check_zone(self.__zname, self.__zclass,
self.__diff.get_rrset_collection(),
(self.__validate_error, self.__validate_warning)):
raise UpdateError('Validation of the new zone failed',
self.__zname, self.__zclass, Rcode.REFUSED)
self.__diff.commit()
return Rcode.NOERROR
except UpdateError:
# Propagate UpdateError exceptions (don't catch them in the
# blocks below)
raise
except isc.datasrc.Error as dse:
logger.info(LIBDDNS_UPDATE_DATASRC_COMMIT_FAILED, dse)
return Rcode.SERVFAIL
except Exception as uce:
logger.error(LIBDDNS_UPDATE_UNCAUGHT_EXCEPTION,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
uce)
return Rcode.SERVFAIL
def __check_update_acl(self, zname, zclass):
'''Apply update ACL for the zone to be updated.'''
acl = self.__zone_config.get_update_acl(zname, zclass)
action = acl.execute(isc.acl.dns.RequestContext(
(self.__client_addr[0], self.__client_addr[1]), self.__tsig))
if action == REJECT:
logger.info(LIBDDNS_UPDATE_DENIED,
ClientFormatter(self.__client_addr, self.__tsig),
ZoneFormatter(zname, zclass))
raise UpdateError('rejected', zname, zclass, Rcode.REFUSED(), True)
if action == DROP:
logger.info(LIBDDNS_UPDATE_DROPPED,
ClientFormatter(self.__client_addr, self.__tsig),
ZoneFormatter(zname, zclass))
raise UpdateError('dropped', zname, zclass, None, True)
logger.debug(logger.DBGLVL_TRACE_BASIC, LIBDDNS_UPDATE_APPROVED,
ClientFormatter(self.__client_addr, self.__tsig),
ZoneFormatter(zname, zclass))
def __do_prescan(self):
'''Perform the prescan as defined in RFC2136 section 3.4.1.
This method has a side-effect; it sets self._new_soa if
it encounters the addition of a SOA record in the update
list (so serial can be checked by update later, etc.).
It puts the added SOA in self.__added_soa.
'''
for rrset in self.__message.get_section(SECTION_UPDATE):
if not self.__check_in_zone(rrset):
logger.info(LIBDDNS_UPDATE_NOTZONE,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset))
return Rcode.NOTZONE()
if rrset.get_class() == self.__zclass:
# In fact, all metatypes are in a specific range,
# so one check can test TKEY to ANY
# (some value check is needed anyway, since we do
# not have defined RRtypes for MAILA and MAILB)
if rrset.get_type().get_code() >= 249:
logger.info(LIBDDNS_UPDATE_ADD_BAD_TYPE,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset))
return Rcode.FORMERR()
if rrset.get_type() == RRType.SOA():
# In case there's multiple soa records in the update
# somehow, just take the last
for rr in foreach_rr(rrset):
self.__set_soa_rrset(rr)
elif rrset.get_class() == RRClass.ANY():
if rrset.get_ttl().get_value() != 0:
logger.info(LIBDDNS_UPDATE_DELETE_NONZERO_TTL,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset))
return Rcode.FORMERR()
if rrset.get_rdata_count() > 0:
logger.info(LIBDDNS_UPDATE_DELETE_RRSET_NOT_EMPTY,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset))
return Rcode.FORMERR()
if rrset.get_type().get_code() >= 249 and\
rrset.get_type().get_code() <= 254:
logger.info(LIBDDNS_UPDATE_DELETE_BAD_TYPE,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset))
return Rcode.FORMERR()
elif rrset.get_class() == RRClass.NONE():
if rrset.get_ttl().get_value() != 0:
logger.info(LIBDDNS_UPDATE_DELETE_RR_NONZERO_TTL,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset))
return Rcode.FORMERR()
if rrset.get_type().get_code() >= 249:
logger.info(LIBDDNS_UPDATE_DELETE_RR_BAD_TYPE,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset))
return Rcode.FORMERR()
else:
logger.info(LIBDDNS_UPDATE_BAD_CLASS,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset))
return Rcode.FORMERR()
return Rcode.NOERROR()
def __check_prerequisites(self):
'''Check the prerequisites section of the UPDATE Message.
RFC2136 Section 2.4.
Returns a dns Rcode signaling either no error (Rcode.NOERROR())
or that one of the prerequisites failed (any other Rcode).
'''
# Temporary array to store exact-match RRsets
exact_match_rrsets = []
for rrset in self.__message.get_section(SECTION_PREREQUISITE):
# First check if the name is in the zone
if not self.__check_in_zone(rrset):
logger.info(LIBDDNS_PREREQ_NOTZONE,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset))
return Rcode.NOTZONE()
# Algorithm taken from RFC2136 Section 3.2
if rrset.get_class() == RRClass.ANY():
if rrset.get_ttl().get_value() != 0 or\
rrset.get_rdata_count() != 0:
logger.info(LIBDDNS_PREREQ_FORMERR_ANY,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset))
return Rcode.FORMERR()
elif rrset.get_type() == RRType.ANY():
if not self.__prereq_name_in_use(rrset):
rcode = Rcode.NXDOMAIN()
logger.info(LIBDDNS_PREREQ_NAME_IN_USE_FAILED,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset), rcode)
return rcode
else:
if not self.__prereq_rrset_exists(rrset):
rcode = Rcode.NXRRSET()
logger.info(LIBDDNS_PREREQ_RRSET_EXISTS_FAILED,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset), rcode)
return rcode
elif rrset.get_class() == RRClass.NONE():
if rrset.get_ttl().get_value() != 0 or\
rrset.get_rdata_count() != 0:
logger.info(LIBDDNS_PREREQ_FORMERR_NONE,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset))
return Rcode.FORMERR()
elif rrset.get_type() == RRType.ANY():
if not self.__prereq_name_not_in_use(rrset):
rcode = Rcode.YXDOMAIN()
logger.info(LIBDDNS_PREREQ_NAME_NOT_IN_USE_FAILED,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset), rcode)
return rcode
else:
if not self.__prereq_rrset_does_not_exist(rrset):
rcode = Rcode.YXRRSET()
logger.info(LIBDDNS_PREREQ_RRSET_DOES_NOT_EXIST_FAILED,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset), rcode)
return rcode
elif rrset.get_class() == self.__zclass:
if rrset.get_ttl().get_value() != 0:
logger.info(LIBDDNS_PREREQ_FORMERR,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset))
return Rcode.FORMERR()
else:
collect_rrsets(exact_match_rrsets, rrset)
else:
logger.info(LIBDDNS_PREREQ_FORMERR_CLASS,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(rrset))
return Rcode.FORMERR()
for collected_rrset in exact_match_rrsets:
if not self.__prereq_rrset_exists_value(collected_rrset):
rcode = Rcode.NXRRSET()
logger.info(LIBDDNS_PREREQ_RRSET_EXISTS_VAL_FAILED,
ClientFormatter(self.__client_addr),
ZoneFormatter(self.__zname, self.__zclass),
RRsetFormatter(collected_rrset), rcode)
return rcode
# All prerequisites are satisfied
return Rcode.NOERROR()
