fix: the equality checks for DNSPointer and DNSService should be case insensitive (#1122)

Author: bdraco

src/zeroconf/_dns.pxd

@@ -60,6 +60,7 @@ cdef class DNSPointer(DNSRecord):
 
     cdef public cython.int _hash
     cdef public object alias
+    cdef public object alias_key
 
     cdef _eq(self, DNSPointer other)
 

src/zeroconf/_dns.py

@@ -314,14 +314,15 @@ class DNSPointer(DNSRecord):
 
     """A DNS pointer record"""
 
-    __slots__ = ('_hash', 'alias')
+    __slots__ = ('_hash', 'alias', 'alias_key')
 
     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
-        self._hash = hash((self.key, type_, self.class_, alias))
+        self.alias_key = self.alias.lower()
+        self._hash = hash((self.key, type_, self.class_, self.alias_key))
 
     @property
     def max_size_compressed(self) -> int:
@@ -343,7 +344,7 @@ def __eq__(self, other: Any) -> bool:
 
     def _eq(self, other) -> bool:  # type: ignore[no-untyped-def]
         """Tests equality on alias."""
-        return self.alias == other.alias and self._dns_entry_matches(other)
+        return self.alias_key == other.alias_key and self._dns_entry_matches(other)
 
     def __hash__(self) -> int:
         """Hash to compare like DNSPointer."""
@@ -415,7 +416,7 @@ def __init__(
         self.port = port
         self.server = server
         self.server_key = server.lower()
-        self._hash = hash((self.key, type_, self.class_, priority, weight, port, server))
+        self._hash = hash((self.key, type_, self.class_, priority, weight, port, self.server_key))
 
     def write(self, out: 'DNSOutgoing') -> None:
         """Used in constructing an outgoing packet"""
@@ -434,7 +435,7 @@ def _eq(self, other) -> bool:  # type: ignore[no-untyped-def]
             self.priority == other.priority
             and self.weight == other.weight
             and self.port == other.port
-            and self.server == other.server
+            and self.server_key == other.server_key
             and self._dns_entry_matches(other)
         )
 

tests/services/test_browser.py

@@ -176,7 +176,7 @@ def update_service(self, zc, type_, name) -> None:  # type: ignore[no-untyped-de
                         socket.AF_INET6, service_v6_second_address
                     ) in service_info.addresses_by_version(r.IPVersion.V6Only)
                 assert service_info.text == service_text
-                assert service_info.server == service_server
+                assert service_info.server.lower() == service_server.lower()
                 service_updated_event.set()
 
         def mock_incoming_msg(service_state_change: r.ServiceStateChange) -> r.DNSIncoming:

tests/test_dns.py

@@ -283,6 +283,14 @@ def test_dns_pointer_record_hashablity():
     assert len(record_set) == 2
 
 
+def test_dns_pointer_comparison_is_case_insensitive():
+    """Test DNSPointer comparison is case insensitive."""
+    ptr1 = r.DNSPointer('irrelevant', const._TYPE_PTR, const._CLASS_IN, const._DNS_OTHER_TTL, '123')
+    ptr2 = r.DNSPointer('irrelevant'.upper(), const._TYPE_PTR, const._CLASS_IN, const._DNS_OTHER_TTL, '123')
+
+    assert ptr1 == ptr2
+
+
 def test_dns_text_record_hashablity():
     """Test DNSText are hashable."""
     text1 = r.DNSText('irrelevant', 0, 0, const._DNS_OTHER_TTL, b'12345678901')
@@ -340,6 +348,17 @@ def test_dns_service_server_key():
     assert srv1.server_key == 'x.local.'
 
 
+def test_dns_service_server_comparison_is_case_insensitive():
+    """Test DNSService server comparison is case insensitive."""
+    srv1 = r.DNSService(
+        'X._tcp._http.local.', const._TYPE_SRV, const._CLASS_IN, const._DNS_HOST_TTL, 0, 0, 80, 'X.local.'
+    )
+    srv2 = r.DNSService(
+        'X._tcp._http.local.', const._TYPE_SRV, const._CLASS_IN, const._DNS_HOST_TTL, 0, 0, 80, 'x.local.'
+    )
+    assert srv1 == srv2
+
+
 def test_dns_nsec_record_hashablity():
     """Test DNSNsec are hashable."""
     nsec1 = r.DNSNsec(