ttl: modify default used to respond to _services queries

andrewbonney · jstasiak · commit f25989d8cdae · 2019-03-31T15:52:48.000+02:00
diff --git a/test_zeroconf.py b/test_zeroconf.py
@@ -59,7 +59,7 @@ def test_dns_hinfo_repr_eq(self):
 
     def test_dns_pointer_repr(self):
         pointer = r.DNSPointer(
-            'irrelevant', r._TYPE_PTR, r._CLASS_IN, r._DNS_TTL, '123')
+            'irrelevant', r._TYPE_PTR, r._CLASS_IN, r._DNS_HOST_TTL, '123')
         repr(pointer)
 
     def test_dns_address_repr(self):
@@ -74,11 +74,11 @@ def test_dns_question_repr(self):
 
     def test_dns_service_repr(self):
         service = r.DNSService(
-            'irrelevant', r._TYPE_SRV, r._CLASS_IN, r._DNS_TTL, 0, 0, 80, b'a')
+            'irrelevant', r._TYPE_SRV, r._CLASS_IN, r._DNS_HOST_TTL, 0, 0, 80, b'a')
         repr(service)
 
     def test_dns_record_abc(self):
-        record = r.DNSRecord('irrelevant', r._TYPE_SRV, r._CLASS_IN, r._DNS_TTL)
+        record = r.DNSRecord('irrelevant', r._TYPE_SRV, r._CLASS_IN, r._DNS_HOST_TTL)
         self.assertRaises(r.AbstractMethodException, record.__eq__, record)
         self.assertRaises(r.AbstractMethodException, record.write, None)
 
@@ -134,7 +134,7 @@ def test_parse_own_packet_question(self):
     def test_parse_own_packet_response(self):
         generated = r.DNSOutgoing(r._FLAGS_QR_RESPONSE)
         generated.add_answer_at_time(r.DNSService(
-            "æøå.local.", r._TYPE_SRV, r._CLASS_IN, r._DNS_TTL, 0, 0, 80, "foo.local."), 0)
+            "æøå.local.", r._TYPE_SRV, r._CLASS_IN, r._DNS_HOST_TTL, 0, 0, 80, "foo.local."), 0)
         parsed = r.DNSIncoming(generated.packet())
         self.assertEqual(len(generated.answers), 1)
         self.assertEqual(len(generated.answers), len(parsed.answers))
@@ -153,11 +153,11 @@ def test_suppress_answer(self):
         question = r.DNSQuestion("testname.local.", r._TYPE_SRV, r._CLASS_IN)
         query_generated.add_question(question)
         answer1 = r.DNSService(
-            "testname1.local.", r._TYPE_SRV, r._CLASS_IN, r._DNS_TTL, 0, 0, 80, "foo.local.")
+            "testname1.local.", r._TYPE_SRV, r._CLASS_IN, r._DNS_HOST_TTL, 0, 0, 80, "foo.local.")
         staleanswer2 = r.DNSService(
-            "testname2.local.", r._TYPE_SRV, r._CLASS_IN, r._DNS_TTL/2, 0, 0, 80, "foo.local.")
+            "testname2.local.", r._TYPE_SRV, r._CLASS_IN, r._DNS_HOST_TTL/2, 0, 0, 80, "foo.local.")
         answer2 = r.DNSService(
-            "testname2.local.", r._TYPE_SRV, r._CLASS_IN, r._DNS_TTL, 0, 0, 80, "foo.local.")
+            "testname2.local.", r._TYPE_SRV, r._CLASS_IN, r._DNS_HOST_TTL, 0, 0, 80, "foo.local.")
         query_generated.add_answer_at_time(answer1, 0)
         query_generated.add_answer_at_time(staleanswer2, 0)
         query = r.DNSIncoming(query_generated.packet())
@@ -441,10 +441,10 @@ def generate_host(zc, host_name, type_):
         out = r.DNSOutgoing(r._FLAGS_QR_RESPONSE | r._FLAGS_AA)
         out.add_answer_at_time(
             r.DNSPointer(type_, r._TYPE_PTR, r._CLASS_IN,
-                         r._DNS_TTL, name), 0)
+                         r._DNS_HOST_TTL, name), 0)
         out.add_answer_at_time(
             r.DNSService(type_, r._TYPE_SRV, r._CLASS_IN,
-                         r._DNS_TTL, 0, 0, 80,
+                         r._DNS_HOST_TTL, 0, 0, 80,
                          name), 0)
         zc.send(out)
 
@@ -609,7 +609,7 @@ def send(out, addr=r._MDNS_ADDR, port=r._MDNS_PORT):
         setattr(zc, "send", send)
 
         # register service with default TTL
-        expected_ttl = r._DNS_TTL
+        expected_ttl = r._DNS_HOST_TTL
         zc.register_service(info)
         assert nbr_answers == 12 and nbr_additionals == 0 and nbr_authorities == 3
         nbr_answers = nbr_additionals = nbr_authorities = 0
@@ -631,8 +631,8 @@ def send(out, addr=r._MDNS_ADDR, port=r._MDNS_PORT):
         nbr_answers = nbr_additionals = nbr_authorities = 0
 
         # register service with custom TTL
-        expected_ttl = r._DNS_TTL * 2
-        assert expected_ttl != r._DNS_TTL
+        expected_ttl = r._DNS_HOST_TTL * 2
+        assert expected_ttl != r._DNS_HOST_TTL
         zc.register_service(info, ttl=expected_ttl)
         assert nbr_answers == 12 and nbr_additionals == 0 and nbr_authorities == 3
         nbr_answers = nbr_additionals = nbr_authorities = 0
@@ -894,7 +894,7 @@ def current_time_millis():
         """Current system time in milliseconds"""
         return time.time() * 1000 + time_offset * 1000
 
-    expected_ttl = r._DNS_TTL
+    expected_ttl = r._DNS_HOST_TTL
 
     nbr_answers = 0
 
diff --git a/zeroconf.py b/zeroconf.py
@@ -74,7 +74,8 @@
 _MDNS_ADDR = '224.0.0.251'
 _MDNS_PORT = 5353
 _DNS_PORT = 53
-_DNS_TTL = 120  # two minutes default TTL as recommended by RFC6762
+_DNS_HOST_TTL = 120  # two minute for host records (A, SRV etc) as-per RFC6762
+_DNS_OTHER_TTL = 4500  # 75 minutes for non-host records (PTR, TXT etc) as-per RFC6762
 
 _MAX_MSG_TYPICAL = 1460  # unused
 _MAX_MSG_ABSOLUTE = 8966
@@ -1835,7 +1836,7 @@ def remove_all_service_listeners(self) -> None:
             self.remove_service_listener(listener)
 
     def register_service(
-        self, info: ServiceInfo, ttl: int = _DNS_TTL, allow_name_change: bool = False,
+        self, info: ServiceInfo, ttl: int = _DNS_HOST_TTL, allow_name_change: bool = False,
     ) -> None:
         """Registers service information to the network with a default TTL
         of 60 seconds.  Zeroconf will then respond to requests for
@@ -2048,7 +2049,7 @@ def handle_query(self, msg: DNSIncoming, addr: str, port: int) -> None:
                             out = DNSOutgoing(_FLAGS_QR_RESPONSE | _FLAGS_AA)
                         out.add_answer(msg, DNSPointer(
                             "_services._dns-sd._udp.local.", _TYPE_PTR,
-                            _CLASS_IN, _DNS_TTL, stype))
+                            _CLASS_IN, _DNS_OTHER_TTL, stype))
                 for service in self.services.values():
                     if question.name == service.type:
                         if out is None:
