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bdracobdraco
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Suppress additionals when answer is suppressed (#690)
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Lines changed: 198 additions & 97 deletions

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‎tests/test_handlers.py‎

Lines changed: 128 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -701,3 +701,131 @@ def test_known_answer_supression_service_type_enumeration_query():
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zc.registry.remove(info)
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zc.registry.remove(info2)
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zc.close()
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def test_qu_response_only_sends_additionals_if_sends_answer():
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"""Test that a QU response does not send additionals unless it sends the answer as well."""
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# instantiate a zeroconf instance
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zc = Zeroconf(interfaces=['127.0.0.1'])
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type_ = "_addtest1._tcp.local."
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name = "knownname"
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registration_name = "%s.%s" % (name, type_)
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desc = {'path': '/~paulsm/'}
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server_name = "ash-2.local."
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info = 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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zc.registry.add(info)
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type_2 = "_addtest2._tcp.local."
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name = "knownname"
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registration_name2 = "%s.%s" % (name, type_2)
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desc = {'path': '/~paulsm/'}
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server_name2 = "ash-3.local."
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info2 = ServiceInfo(
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type_2, registration_name2, 80, 0, 0, desc, server_name2, addresses=[socket.inet_aton("10.0.1.2")]
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)
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zc.registry.add(info2)
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ptr_record = info.dns_pointer()
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# Add the PTR record to the cache
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zc.cache.add(ptr_record)
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# Add the A record to the cache with 50% ttl remaining
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a_record = info.dns_addresses()[0]
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a_record._set_created_ttl(current_time_millis() - (a_record.ttl * 1000 / 2), a_record.ttl)
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assert not a_record.is_recent(current_time_millis())
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zc.cache.add(a_record)
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# With QU should respond to only unicast when the answer has been recently multicast
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# even if the additional has not been recently multicast
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query = r.DNSOutgoing(const._FLAGS_QR_QUERY)
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question = r.DNSQuestion(info.type, const._TYPE_PTR, const._CLASS_IN)
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question.unique = True # Set the QU bit
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assert question.unicast is True
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query.add_question(question)
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unicast_out, multicast_out = zc.query_handler.response(
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[r.DNSIncoming(packet) for packet in query.packets()], "1.2.3.4", const._MDNS_PORT
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)
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assert multicast_out is None
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assert a_record in unicast_out.additionals
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assert unicast_out.answers[0][0] == ptr_record
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# Remove the 50% A record and add a 100% A record
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zc.cache.remove(a_record)
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a_record = info.dns_addresses()[0]
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assert a_record.is_recent(current_time_millis())
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zc.cache.add(a_record)
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# With QU should respond to only unicast when the answer has been recently multicast
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# even if the additional has not been recently multicast
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query = r.DNSOutgoing(const._FLAGS_QR_QUERY)
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question = r.DNSQuestion(info.type, const._TYPE_PTR, const._CLASS_IN)
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question.unique = True # Set the QU bit
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assert question.unicast is True
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query.add_question(question)
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unicast_out, multicast_out = zc.query_handler.response(
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[r.DNSIncoming(packet) for packet in query.packets()], "1.2.3.4", const._MDNS_PORT
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)
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assert multicast_out is None
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assert a_record in unicast_out.additionals
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assert unicast_out.answers[0][0] == ptr_record
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# Remove the 100% PTR record and add a 50% PTR record
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zc.cache.remove(ptr_record)
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ptr_record._set_created_ttl(current_time_millis() - (ptr_record.ttl * 1000 / 2), ptr_record.ttl)
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assert not ptr_record.is_recent(current_time_millis())
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zc.cache.add(ptr_record)
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# With QU should respond to only multicast since the has less
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# than 75% of its ttl remaining
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query = r.DNSOutgoing(const._FLAGS_QR_QUERY)
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question = r.DNSQuestion(info.type, const._TYPE_PTR, const._CLASS_IN)
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question.unique = True # Set the QU bit
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assert question.unicast is True
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query.add_question(question)
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unicast_out, multicast_out = zc.query_handler.response(
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[r.DNSIncoming(packet) for packet in query.packets()], "1.2.3.4", const._MDNS_PORT
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)
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assert multicast_out.answers[0][0] == ptr_record
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assert a_record in multicast_out.additionals
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assert info.dns_text() in multicast_out.additionals
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assert info.dns_service() in multicast_out.additionals
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assert unicast_out is None
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# Ask 2 QU questions, with info the PTR is at 50%, with info2 the PTR is at 100%
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# We should get back a unicast reply for info2, but info should be multicasted since its within 75% of its TTL
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# With QU should respond to only multicast since the has less
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# than 75% of its ttl remaining
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query = r.DNSOutgoing(const._FLAGS_QR_QUERY)
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question = r.DNSQuestion(info.type, const._TYPE_PTR, const._CLASS_IN)
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question.unique = True # Set the QU bit
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assert question.unicast is True
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query.add_question(question)
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question = r.DNSQuestion(info2.type, const._TYPE_PTR, const._CLASS_IN)
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question.unique = True # Set the QU bit
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assert question.unicast is True
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query.add_question(question)
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zc.cache.add(info2.dns_pointer()) # Add 100% TTL for info2 to the cache
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unicast_out, multicast_out = zc.query_handler.response(
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[r.DNSIncoming(packet) for packet in query.packets()], "1.2.3.4", const._MDNS_PORT
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)
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assert multicast_out.answers[0][0] == info.dns_pointer()
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assert info.dns_addresses()[0] in multicast_out.additionals
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assert info.dns_text() in multicast_out.additionals
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assert info.dns_service() in multicast_out.additionals
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assert unicast_out.answers[0][0] == info2.dns_pointer()
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assert info2.dns_addresses()[0] in unicast_out.additionals
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assert info2.dns_text() in unicast_out.additionals
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assert info2.dns_service() in unicast_out.additionals
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# unregister
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zc.registry.remove(info)
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zc.close()

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