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bdracobdraco
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Implement multi-packet known answer supression (#687)
- Implements https://datatracker.ietf.org/doc/html/rfc6762#section-7.2 - Fixes #499
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4 files changed

Lines changed: 324 additions & 50 deletions

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‎tests/test_core.py‎

Lines changed: 183 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -4,6 +4,7 @@
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""" Unit tests for zeroconf._core """
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import asyncio
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import itertools
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import logging
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import os
@@ -18,7 +19,7 @@
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import zeroconf as r
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from zeroconf import _core, const, ServiceBrowser, Zeroconf
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from . import has_working_ipv6, _inject_response
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from . import has_working_ipv6, _clear_cache, _inject_response
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log = logging.getLogger('zeroconf')
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original_logging_level = logging.NOTSET
@@ -423,3 +424,184 @@ def test_sending_unicast():
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assert zc.cache.get(entry) is not None
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zc.close()
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def test_tc_bit_defers():
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zc = Zeroconf(interfaces=['127.0.0.1'])
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type_ = "_tcbitdefer._tcp.local."
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name = "knownname"
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name2 = "knownname2"
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name3 = "knownname3"
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registration_name = "%s.%s" % (name, type_)
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registration2_name = "%s.%s" % (name2, type_)
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registration3_name = "%s.%s" % (name3, type_)
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desc = {'path': '/~paulsm/'}
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server_name = "ash-2.local."
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server_name2 = "ash-3.local."
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server_name3 = "ash-4.local."
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info = r.ServiceInfo(
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type_, registration_name, 80, 0, 0, desc, server_name, addresses=[socket.inet_aton("10.0.1.2")]
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)
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info2 = r.ServiceInfo(
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type_, registration2_name, 80, 0, 0, desc, server_name2, addresses=[socket.inet_aton("10.0.1.2")]
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)
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info3 = r.ServiceInfo(
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type_, registration3_name, 80, 0, 0, desc, server_name3, addresses=[socket.inet_aton("10.0.1.2")]
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)
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zc.registry.add(info)
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zc.registry.add(info2)
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zc.registry.add(info3)
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def threadsafe_query(*args):
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async def make_query():
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zc.handle_query(*args)
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asyncio.run_coroutine_threadsafe(make_query(), zc.loop).result()
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now = r.current_time_millis()
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_clear_cache(zc)
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generated = r.DNSOutgoing(const._FLAGS_QR_QUERY)
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question = r.DNSQuestion(type_, const._TYPE_PTR, const._CLASS_IN)
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generated.add_question(question)
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for _ in range(300):
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# Add so many answers we end up with another packet
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generated.add_answer_at_time(info.dns_pointer(), now)
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generated.add_answer_at_time(info2.dns_pointer(), now)
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generated.add_answer_at_time(info3.dns_pointer(), now)
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packets = generated.packets()
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assert len(packets) == 4
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expected_deferred = []
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source_ip = '203.0.113.13'
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next_packet = r.DNSIncoming(packets.pop(0))
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expected_deferred.append(next_packet)
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threadsafe_query(next_packet, source_ip, const._MDNS_PORT)
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assert zc._deferred[source_ip] == expected_deferred
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assert source_ip in zc._timers
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next_packet = r.DNSIncoming(packets.pop(0))
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expected_deferred.append(next_packet)
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threadsafe_query(next_packet, source_ip, const._MDNS_PORT)
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assert zc._deferred[source_ip] == expected_deferred
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assert source_ip in zc._timers
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threadsafe_query(next_packet, source_ip, const._MDNS_PORT)
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assert zc._deferred[source_ip] == expected_deferred
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assert source_ip in zc._timers
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next_packet = r.DNSIncoming(packets.pop(0))
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expected_deferred.append(next_packet)
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threadsafe_query(next_packet, source_ip, const._MDNS_PORT)
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assert zc._deferred[source_ip] == expected_deferred
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assert source_ip in zc._timers
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next_packet = r.DNSIncoming(packets.pop(0))
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expected_deferred.append(next_packet)
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threadsafe_query(next_packet, source_ip, const._MDNS_PORT)
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assert source_ip not in zc._deferred
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assert source_ip not in zc._timers
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# unregister
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zc.unregister_service(info)
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zc.close()
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def test_tc_bit_defers_last_response_missing():
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zc = Zeroconf(interfaces=['127.0.0.1'])
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type_ = "_knowndefer._tcp.local."
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name = "knownname"
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name2 = "knownname2"
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name3 = "knownname3"
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registration_name = "%s.%s" % (name, type_)
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registration2_name = "%s.%s" % (name2, type_)
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registration3_name = "%s.%s" % (name3, type_)
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desc = {'path': '/~paulsm/'}
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server_name = "ash-2.local."
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server_name2 = "ash-3.local."
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server_name3 = "ash-4.local."
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info = r.ServiceInfo(
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type_, registration_name, 80, 0, 0, desc, server_name, addresses=[socket.inet_aton("10.0.1.2")]
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)
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info2 = r.ServiceInfo(
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type_, registration2_name, 80, 0, 0, desc, server_name2, addresses=[socket.inet_aton("10.0.1.2")]
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)
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info3 = r.ServiceInfo(
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type_, registration3_name, 80, 0, 0, desc, server_name3, addresses=[socket.inet_aton("10.0.1.2")]
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)
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zc.registry.add(info)
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zc.registry.add(info2)
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zc.registry.add(info3)
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def threadsafe_query(*args):
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async def make_query():
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zc.handle_query(*args)
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asyncio.run_coroutine_threadsafe(make_query(), zc.loop).result()
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now = r.current_time_millis()
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_clear_cache(zc)
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source_ip = '203.0.113.12'
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generated = r.DNSOutgoing(const._FLAGS_QR_QUERY)
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question = r.DNSQuestion(type_, const._TYPE_PTR, const._CLASS_IN)
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generated.add_question(question)
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for _ in range(300):
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# Add so many answers we end up with another packet
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generated.add_answer_at_time(info.dns_pointer(), now)
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generated.add_answer_at_time(info2.dns_pointer(), now)
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generated.add_answer_at_time(info3.dns_pointer(), now)
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packets = generated.packets()
560+
assert len(packets) == 4
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expected_deferred = []
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next_packet = r.DNSIncoming(packets.pop(0))
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expected_deferred.append(next_packet)
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threadsafe_query(next_packet, source_ip, const._MDNS_PORT)
566+
assert zc._deferred[source_ip] == expected_deferred
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timer1 = zc._timers[source_ip]
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569+
next_packet = r.DNSIncoming(packets.pop(0))
570+
expected_deferred.append(next_packet)
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threadsafe_query(next_packet, source_ip, const._MDNS_PORT)
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assert zc._deferred[source_ip] == expected_deferred
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timer2 = zc._timers[source_ip]
574+
if sys.version_info >= (3, 7):
575+
assert timer1.cancelled()
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assert timer2 != timer1
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# Send the same packet again to similar multi interfaces
579+
threadsafe_query(next_packet, source_ip, const._MDNS_PORT)
580+
assert zc._deferred[source_ip] == expected_deferred
581+
assert source_ip in zc._timers
582+
timer3 = zc._timers[source_ip]
583+
if sys.version_info >= (3, 7):
584+
assert not timer3.cancelled()
585+
assert timer3 == timer2
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587+
next_packet = r.DNSIncoming(packets.pop(0))
588+
expected_deferred.append(next_packet)
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threadsafe_query(next_packet, source_ip, const._MDNS_PORT)
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assert zc._deferred[source_ip] == expected_deferred
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assert source_ip in zc._timers
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timer4 = zc._timers[source_ip]
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if sys.version_info >= (3, 7):
594+
assert timer3.cancelled()
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assert timer4 != timer3
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for _ in range(7):
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time.sleep(0.1)
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if source_ip not in zc._timers:
600+
break
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assert source_ip not in zc._deferred
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assert source_ip not in zc._timers
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# unregister
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zc.registry.remove(info)
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zc.close()

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