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Merged
bdraco merged 1 commit into from
Jun 17, 2021
Merged

Synchronize created time for incoming and outgoing queries #709

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26 changes: 26 additions & 0 deletions tests/test_protocol.py
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Original file line number Diff line number Diff line change
Expand Up @@ -720,3 +720,29 @@ def test_qu_packet_parser():
parsed = DNSIncoming(qu_packet)
assert parsed.questions[0].unicast is True
assert ",QU," in str(parsed.questions[0])


def test_records_same_packet_share_fate():
"""Test records in the same packet all have the same created time."""
out = r.DNSOutgoing(const._FLAGS_QR_QUERY | const._FLAGS_AA)
type_ = "_hap._tcp.local."
out.add_question(r.DNSQuestion(type_, const._TYPE_PTR, const._CLASS_IN))

for i in range(30):
out.add_answer_at_time(
DNSText(
("HASS Bridge W9DN %s._hap._tcp.local." % i),
const._TYPE_TXT,
const._CLASS_IN | const._CLASS_UNIQUE,
const._DNS_OTHER_TTL,
b'\x13md=HASS Bridge W9DN\x06pv=1.0\x14id=11:8E:DB:5B:5C:C5\x05c#=12\x04s#=1'
b'\x04ff=0\x04ci=2\x04sf=0\x0bsh=6fLM5A==',
),
0,
)

for packet in out.packets():
dnsin = DNSIncoming(packet)
first_time = dnsin.answers[0].created
for answer in dnsin.answers:
assert answer.created == first_time
11 changes: 6 additions & 5 deletions zeroconf/_core.py
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Original file line number Diff line number Diff line change
Expand Up @@ -465,19 +465,20 @@ def generate_service_query(self, info: ServiceInfo) -> DNSOutgoing: # pylint: d
#
# _CLASS_UNIQUE is the "QU" bit
out.add_question(DNSQuestion(info.type, _TYPE_PTR, _CLASS_IN | _CLASS_UNIQUE))
out.add_authorative_answer(info.dns_pointer())
out.add_authorative_answer(info.dns_pointer(created=current_time_millis()))
return out

def _add_broadcast_answer( # pylint: disable=no-self-use
self, out: DNSOutgoing, info: ServiceInfo, override_ttl: Optional[int]
) -> None:
"""Add answers to broadcast a service."""
now = current_time_millis()
other_ttl = info.other_ttl if override_ttl is None else override_ttl
host_ttl = info.host_ttl if override_ttl is None else override_ttl
out.add_answer_at_time(info.dns_pointer(override_ttl=other_ttl), 0)
out.add_answer_at_time(info.dns_service(override_ttl=host_ttl), 0)
out.add_answer_at_time(info.dns_text(override_ttl=other_ttl), 0)
for dns_address in info.dns_addresses(override_ttl=host_ttl):
out.add_answer_at_time(info.dns_pointer(override_ttl=other_ttl, created=now), 0)
out.add_answer_at_time(info.dns_service(override_ttl=host_ttl, created=now), 0)
out.add_answer_at_time(info.dns_text(override_ttl=other_ttl, created=now), 0)
for dns_address in info.dns_addresses(override_ttl=host_ttl, created=now):
out.add_answer_at_time(dns_address, 0)

def unregister_service(self, info: ServiceInfo) -> None:
Expand Down
33 changes: 22 additions & 11 deletions zeroconf/_dns.py
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Original file line number Diff line number Diff line change
Expand Up @@ -139,10 +139,12 @@ class DNSRecord(DNSEntry):
"""A DNS record - like a DNS entry, but has a TTL"""

# TODO: Switch to just int ttl
def __init__(self, name: str, type_: int, class_: int, ttl: Union[float, int]) -> None:
def __init__(
self, name: str, type_: int, class_: int, ttl: Union[float, int], created: Optional[float] = None
) -> None:
super().__init__(name, type_, class_)
self.ttl = ttl
self.created = current_time_millis()
self.created = created or current_time_millis()
self._expiration_time: Optional[float] = None
self._stale_time: Optional[float] = None
self._recent_time: Optional[float] = None
Expand Down Expand Up @@ -218,8 +220,10 @@ class DNSAddress(DNSRecord):

"""A DNS address record"""

def __init__(self, name: str, type_: int, class_: int, ttl: int, address: bytes) -> None:
super().__init__(name, type_, class_, ttl)
def __init__(
self, name: str, type_: int, class_: int, ttl: int, address: bytes, created: Optional[float] = None
) -> None:
super().__init__(name, type_, class_, ttl, created)
self.address = address

def write(self, out: 'DNSOutgoing') -> None:
Expand Down Expand Up @@ -252,8 +256,10 @@ class DNSHinfo(DNSRecord):

"""A DNS host information record"""

def __init__(self, name: str, type_: int, class_: int, ttl: int, cpu: str, os: str) -> None:
super().__init__(name, type_, class_, ttl)
def __init__(
self, name: str, type_: int, class_: int, ttl: int, cpu: str, os: str, created: Optional[float] = None
) -> None:
super().__init__(name, type_, class_, ttl, created)
self.cpu = cpu
self.os = os

Expand Down Expand Up @@ -284,8 +290,10 @@ class DNSPointer(DNSRecord):

"""A DNS pointer record"""

def __init__(self, name: str, type_: int, class_: int, ttl: int, alias: str) -> None:
super().__init__(name, type_, class_, ttl)
def __init__(
self, name: str, type_: int, class_: int, ttl: int, alias: str, created: Optional[float] = None
) -> None:
super().__init__(name, type_, class_, ttl, created)
self.alias = alias

@property
Expand Down Expand Up @@ -319,9 +327,11 @@ class DNSText(DNSRecord):

"""A DNS text record"""

def __init__(self, name: str, type_: int, class_: int, ttl: int, text: bytes) -> None:
def __init__(
self, name: str, type_: int, class_: int, ttl: int, text: bytes, created: Optional[float] = None
) -> None:
assert isinstance(text, (bytes, type(None)))
super().__init__(name, type_, class_, ttl)
super().__init__(name, type_, class_, ttl, created)
self.text = text

def write(self, out: 'DNSOutgoing') -> None:
Expand Down Expand Up @@ -357,8 +367,9 @@ def __init__(
weight: int,
port: int,
server: str,
created: Optional[float] = None,
) -> None:
super().__init__(name, type_, class_, ttl)
super().__init__(name, type_, class_, ttl, created)
self.priority = priority
self.weight = weight
self.port = port
Expand Down
44 changes: 29 additions & 15 deletions zeroconf/_handlers.py
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Original file line number Diff line number Diff line change
Expand Up @@ -162,67 +162,80 @@ def __init__(self, registry: ServiceRegistry, cache: DNSCache) -> None:
self.cache = cache

def _add_service_type_enumeration_query_answers(
self, answer_set: _AnswerWithAdditionalsType, known_answers: DNSRRSet
self, answer_set: _AnswerWithAdditionalsType, known_answers: DNSRRSet, now: float
) -> None:
"""Provide an answer to a service type enumeration query.

https://datatracker.ietf.org/doc/html/rfc6763#section-9
"""
for stype in self.registry.get_types():
dns_pointer = DNSPointer(
_SERVICE_TYPE_ENUMERATION_NAME, _TYPE_PTR, _CLASS_IN, _DNS_OTHER_TTL, stype
_SERVICE_TYPE_ENUMERATION_NAME, _TYPE_PTR, _CLASS_IN, _DNS_OTHER_TTL, stype, now
)
if not known_answers.suppresses(dns_pointer):
answer_set[dns_pointer] = set()

def _add_pointer_answers(
self, name: str, answer_set: _AnswerWithAdditionalsType, known_answers: DNSRRSet
self, name: str, answer_set: _AnswerWithAdditionalsType, known_answers: DNSRRSet, now: float
) -> None:
"""Answer PTR/ANY question."""
for service in self.registry.get_infos_type(name):
# Add recommended additional answers according to
# https://tools.ietf.org/html/rfc6763#section-12.1.
dns_pointer = service.dns_pointer()
dns_pointer = service.dns_pointer(created=now)
if not known_answers.suppresses(dns_pointer):
answer_set[dns_pointer] = set(
[service.dns_service(), service.dns_text(), *service.dns_addresses()]
[
service.dns_service(created=now),
service.dns_text(created=now),
*service.dns_addresses(created=now),
]
)

def _add_address_answers(
self, name: str, answer_set: _AnswerWithAdditionalsType, known_answers: DNSRRSet, type_: int
self,
name: str,
answer_set: _AnswerWithAdditionalsType,
known_answers: DNSRRSet,
now: float,
type_: int,
) -> None:
"""Answer A/AAAA/ANY question."""
for service in self.registry.get_infos_server(name):
for dns_address in service.dns_addresses(version=_TYPE_TO_IP_VERSION[type_]):
for dns_address in service.dns_addresses(version=_TYPE_TO_IP_VERSION[type_], created=now):
if not known_answers.suppresses(dns_address):
answer_set[dns_address] = set()

def _answer_question(
self, question: DNSQuestion, answer_set: _AnswerWithAdditionalsType, known_answers: DNSRRSet
self,
question: DNSQuestion,
answer_set: _AnswerWithAdditionalsType,
known_answers: DNSRRSet,
now: float,
) -> None:
if question.type == _TYPE_PTR and question.name.lower() == _SERVICE_TYPE_ENUMERATION_NAME:
self._add_service_type_enumeration_query_answers(answer_set, known_answers)
self._add_service_type_enumeration_query_answers(answer_set, known_answers, now)
return

type_ = question.type

if type_ in (_TYPE_PTR, _TYPE_ANY):
self._add_pointer_answers(question.name, answer_set, known_answers)
self._add_pointer_answers(question.name, answer_set, known_answers, now)

if type_ in (_TYPE_A, _TYPE_AAAA, _TYPE_ANY):
self._add_address_answers(question.name, answer_set, known_answers, type_)
self._add_address_answers(question.name, answer_set, known_answers, now, type_)

if type_ in (_TYPE_SRV, _TYPE_TXT, _TYPE_ANY):
service = self.registry.get_info_name(question.name) # type: ignore
if service is not None:
if type_ in (_TYPE_SRV, _TYPE_ANY):
# Add recommended additional answers according to
# https://tools.ietf.org/html/rfc6763#section-12.2.
dns_service = service.dns_service()
dns_service = service.dns_service(created=now)
if not known_answers.suppresses(dns_service):
answer_set[dns_service] = set(service.dns_addresses())
answer_set[dns_service] = set(service.dns_addresses(created=now))
if type_ in (_TYPE_TXT, _TYPE_ANY):
dns_text = service.dns_text()
dns_text = service.dns_text(created=now)
if not known_answers.suppresses(dns_text):
answer_set[dns_text] = set()

Expand All @@ -233,10 +246,11 @@ def response( # pylint: disable=unused-argument
ucast_source = port != _MDNS_PORT
known_answers = DNSRRSet(itertools.chain(*[msg.answers for msg in msgs]))
query_res = _QueryResponse(self.cache, msgs[0], ucast_source)
now = current_time_millis()

for question in itertools.chain(*[msg.questions for msg in msgs]):
answer_set: _AnswerWithAdditionalsType = {}
self._answer_question(question, answer_set, known_answers)
self._answer_question(question, answer_set, known_answers, now)
if not ucast_source and question.unicast:
query_res.add_qu_question_response(answer_set)
else:
Expand Down
13 changes: 9 additions & 4 deletions zeroconf/_protocol.py
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Original file line number Diff line number Diff line change
Expand Up @@ -24,10 +24,12 @@
import struct
from typing import Any, Dict, List, Optional, TYPE_CHECKING, Tuple, Union, cast


from ._dns import DNSAddress, DNSHinfo, DNSPointer, DNSQuestion, DNSRecord, DNSService, DNSText
from ._exceptions import IncomingDecodeError, NamePartTooLongException
from ._logger import QuietLogger, log
from ._utils.struct import int2byte
from ._utils.time import current_time_millis
from .const import (
_CLASS_UNIQUE,
_DNS_PACKET_HEADER_LEN,
Expand Down Expand Up @@ -90,6 +92,7 @@ def __init__(self, data: bytes) -> None:
self.num_authorities = 0
self.num_additionals = 0
self.valid = False
self.now = current_time_millis()

try:
self.read_header()
Expand Down Expand Up @@ -166,11 +169,11 @@ def read_others(self) -> None:
type_, class_, ttl, length = self.unpack(b'!HHiH')
rec: Optional[DNSRecord] = None
if type_ == _TYPE_A:
rec = DNSAddress(domain, type_, class_, ttl, self.read_string(4))
rec = DNSAddress(domain, type_, class_, ttl, self.read_string(4), self.now)
elif type_ in (_TYPE_CNAME, _TYPE_PTR):
rec = DNSPointer(domain, type_, class_, ttl, self.read_name())
rec = DNSPointer(domain, type_, class_, ttl, self.read_name(), self.now)
elif type_ == _TYPE_TXT:
rec = DNSText(domain, type_, class_, ttl, self.read_string(length))
rec = DNSText(domain, type_, class_, ttl, self.read_string(length), self.now)
elif type_ == _TYPE_SRV:
rec = DNSService(
domain,
Expand All @@ -181,6 +184,7 @@ def read_others(self) -> None:
self.read_unsigned_short(),
self.read_unsigned_short(),
self.read_name(),
self.now,
)
elif type_ == _TYPE_HINFO:
rec = DNSHinfo(
Expand All @@ -190,9 +194,10 @@ def read_others(self) -> None:
ttl,
self.read_character_string().decode('utf-8'),
self.read_character_string().decode('utf-8'),
self.now,
)
elif type_ == _TYPE_AAAA:
rec = DNSAddress(domain, type_, class_, ttl, self.read_string(16))
rec = DNSAddress(domain, type_, class_, ttl, self.read_string(16), self.now)
else:
# Try to ignore types we don't know about
# Skip the payload for the resource record so the next
Expand Down
17 changes: 12 additions & 5 deletions zeroconf/_services/__init__.py
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Expand Up @@ -369,7 +369,7 @@ def update_records_complete(self) -> None:

At this point the cache will have the new records.
"""
# Cannot use .update here since PyPy can fail with
# Cannot use .update here since can fail with
# RuntimeError: dictionary changed size during iteration
# for threaded ServiceBrowsers
while self._pending_handlers:
Expand Down Expand Up @@ -722,7 +722,10 @@ def _process_record(self, record: DNSRecord, now: float) -> None:
self._set_text(record.text)

def dns_addresses(
self, override_ttl: Optional[int] = None, version: IPVersion = IPVersion.All
self,
override_ttl: Optional[int] = None,
version: IPVersion = IPVersion.All,
created: Optional[float] = None,
) -> List[DNSAddress]:
"""Return matching DNSAddress from ServiceInfo."""
return [
Expand All @@ -732,21 +735,23 @@ def dns_addresses(
_CLASS_IN | _CLASS_UNIQUE,
override_ttl if override_ttl is not None else self.host_ttl,
address,
created,
)
for address in self.addresses_by_version(version)
]

def dns_pointer(self, override_ttl: Optional[int] = None) -> DNSPointer:
def dns_pointer(self, override_ttl: Optional[int] = None, created: Optional[float] = None) -> DNSPointer:
"""Return DNSPointer from ServiceInfo."""
return DNSPointer(
self.type,
_TYPE_PTR,
_CLASS_IN,
override_ttl if override_ttl is not None else self.other_ttl,
self.name,
created,
)

def dns_service(self, override_ttl: Optional[int] = None) -> DNSService:
def dns_service(self, override_ttl: Optional[int] = None, created: Optional[float] = None) -> DNSService:
"""Return DNSService from ServiceInfo."""
return DNSService(
self.name,
Expand All @@ -757,16 +762,18 @@ def dns_service(self, override_ttl: Optional[int] = None) -> DNSService:
self.weight,
cast(int, self.port),
self.server,
created,
)

def dns_text(self, override_ttl: Optional[int] = None) -> DNSText:
def dns_text(self, override_ttl: Optional[int] = None, created: Optional[float] = None) -> DNSText:
"""Return DNSText from ServiceInfo."""
return DNSText(
self.name,
_TYPE_TXT,
_CLASS_IN | _CLASS_UNIQUE,
override_ttl if override_ttl is not None else self.other_ttl,
self.text,
created,
)

def _get_address_records_from_cache(self, zc: 'Zeroconf') -> List[DNSRecord]:
Expand Down