🐛 zeroconf: Add missing answers to PTR query

Backported from upstream.

Closes #3813

.git-blame-ignore-revs

@@ -2,6 +2,7 @@
 
 # Switch to black formatting
 1f93b2355a2816918e11a55e61b42010d15a6720
+5f2a95d154650366078b0d387e5b01427c4340c0
 
 # Switch to prettier formatting
 6b44909f21ee39237b7504cd31ffa6cf28275c33

setup.py

@@ -75,7 +75,7 @@
     "scandir>=1.10,<2",
     "chainmap>=1.0.3,<2",
     "typing>=3.7.4.1,<4",
-    "enum34>=1.1.10",
+    "enum34>=1.1.10,<1.2",
 ]
 
 # Python 3 specific requirements

src/octoprint/vendor/zeroconf.py

@@ -74,7 +74,8 @@
 _MDNS_ADDR = "224.0.0.251"
 _MDNS_PORT = 5353
 _DNS_PORT = 53
-_DNS_TTL = 60 * 60  # one hour default TTL
+_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
@@ -1401,6 +1402,8 @@ def __init__(
         priority=0,
         properties=None,
         server=None,
+        host_ttl=_DNS_HOST_TTL,
+        other_ttl=_DNS_OTHER_TTL,
     ):
         """Create a service description.
 
@@ -1413,7 +1416,10 @@ def __init__(
         priority: priority of the service
         properties: dictionary of properties (or a string holding the
                     bytes for the text field)
-        server: fully qualified name for service host (defaults to name)"""
+        server: fully qualified name for service host (defaults to name)
+        host_ttl: ttl used for A/SRV records
+        other_ttl: ttl used for PTR/TXT records
+        """
 
         if not type_.endswith(service_type_name(name)):
             raise BadTypeInNameException
@@ -1439,6 +1445,8 @@ def __init__(
             self.server = name
         self._properties = {}
         self._set_properties(properties)
+        self.host_ttl = host_ttl
+        self.other_ttl = other_ttl
 
     @property
     def addresses(self):
@@ -1845,9 +1853,9 @@ def remove_all_service_listeners(self):
         for listener in [k for k in self.browsers]:
             self.remove_service_listener(listener)
 
-    def register_service(self, info, ttl=_DNS_TTL, allow_name_change=False):
+    def register_service(self, info, ttl=_DNS_HOST_TTL, allow_name_change=False):
         """Registers service information to the network with a default TTL
-        of 60 seconds.  Zeroconf will then respond to requests for
+        of 120 seconds.  Zeroconf will then respond to requests for
         information for that service.  The name of the service may be
         changed if needed to make it unique on the network."""
         self.check_service(info, allow_name_change)
@@ -2018,7 +2026,7 @@ def check_service(self, info, allow_name_change):
             self.debug = out
             out.add_question(DNSQuestion(info.type, _TYPE_PTR, _CLASS_IN))
             out.add_authorative_answer(
-                DNSPointer(info.type, _TYPE_PTR, _CLASS_IN, _DNS_TTL, info.name)
+                DNSPointer(info.type, _TYPE_PTR, _CLASS_IN, info.other_ttl, info.name)
             )
             self.send(out)
             i += 1
@@ -2093,7 +2101,7 @@ def handle_query(self, msg, addr, port):
                                 "_services._dns-sd._udp.local.",
                                 _TYPE_PTR,
                                 _CLASS_IN,
-                                _DNS_TTL,
+                                _DNS_OTHER_TTL,
                                 stype,
                             ),
                         )
@@ -2104,9 +2112,47 @@ def handle_query(self, msg, addr, port):
                         out.add_answer(
                             msg,
                             DNSPointer(
-                                service.type, _TYPE_PTR, _CLASS_IN, _DNS_TTL, service.name
+                                service.type,
+                                _TYPE_PTR,
+                                _CLASS_IN,
+                                service.other_ttl,
+                                service.name,
                             ),
                         )
+
+                        # Add recommended additional answers according to
+                        # https://tools.ietf.org/html/rfc6763#section-12.1.
+                        out.add_additional_answer(
+                            DNSService(
+                                service.name,
+                                _TYPE_SRV,
+                                _CLASS_IN | _CLASS_UNIQUE,
+                                service.host_ttl,
+                                service.priority,
+                                service.weight,
+                                service.port,
+                                service.server,
+                            )
+                        )
+                        out.add_additional_answer(
+                            DNSText(
+                                service.name,
+                                _TYPE_TXT,
+                                _CLASS_IN | _CLASS_UNIQUE,
+                                service.other_ttl,
+                                service.text,
+                            )
+                        )
+                        for address in service.addresses:
+                            out.add_additional_answer(
+                                DNSAddress(
+                                    service.server,
+                                    _TYPE_A,
+                                    _CLASS_IN | _CLASS_UNIQUE,
+                                    service.host_ttl,
+                                    address,
+                                )
+                            )
             else:
                 try:
                     if out is None:
@@ -2123,7 +2169,7 @@ def handle_query(self, msg, addr, port):
                                             question.name,
                                             _TYPE_A,
                                             _CLASS_IN | _CLASS_UNIQUE,
-                                            _DNS_TTL,
+                                            service.host_ttl,
                                             address,
                                         ),
                                     )
@@ -2139,7 +2185,7 @@ def handle_query(self, msg, addr, port):
                                 question.name,
                                 _TYPE_SRV,
                                 _CLASS_IN | _CLASS_UNIQUE,
-                                _DNS_TTL,
+                                service.host_ttl,
                                 service.priority,
                                 service.weight,
                                 service.port,
@@ -2153,7 +2199,7 @@ def handle_query(self, msg, addr, port):
                                 question.name,
                                 _TYPE_TXT,
                                 _CLASS_IN | _CLASS_UNIQUE,
-                                _DNS_TTL,
+                                service.other_ttl,
                                 service.text,
                             ),
                         )
@@ -2164,7 +2210,7 @@ def handle_query(self, msg, addr, port):
                                     service.server,
                                     _TYPE_A,
                                     _CLASS_IN | _CLASS_UNIQUE,
-                                    _DNS_TTL,
+                                    service.host_ttl,
                                     address,
                                 )
                             )