fix: correct handling of IPv6 addresses with scope_id in ServiceInfo (#…

…1322)

examples/browser.py

@@ -51,18 +51,18 @@ def on_service_state_change(
     parser.add_argument('--debug', action='store_true')
     parser.add_argument('--find', action='store_true', help='Browse all available services')
     version_group = parser.add_mutually_exclusive_group()
-    version_group.add_argument('--v6', action='store_true')
     version_group.add_argument('--v6-only', action='store_true')
+    version_group.add_argument('--v4-only', action='store_true')
     args = parser.parse_args()
 
     if args.debug:
         logging.getLogger('zeroconf').setLevel(logging.DEBUG)
-    if args.v6:
-        ip_version = IPVersion.All
-    elif args.v6_only:
+    if args.v6_only:
         ip_version = IPVersion.V6Only
-    else:
+    elif args.v4_only:
         ip_version = IPVersion.V4Only
+    else:
+        ip_version = IPVersion.All
 
     zeroconf = Zeroconf(ip_version=ip_version)
 

src/zeroconf/_services/info.pxd

@@ -32,6 +32,14 @@ cdef object _IPVersion_V4Only_value
 cdef cython.set _ADDRESS_RECORD_TYPES
 
 cdef bint TYPE_CHECKING
+cdef bint IPADDRESS_SUPPORTS_SCOPE_ID
+
+cdef _get_ip_address_object_from_record(DNSAddress record)
+
+@cython.locals(address_str=str)
+cdef _str_without_scope_id(object addr)
+
+cdef _ip_bytes_and_scope_to_address(object addr, object scope_id)
 
 cdef class ServiceInfo(RecordUpdateListener):
 

src/zeroconf/_services/info.py

@@ -22,6 +22,7 @@
 
 import asyncio
 import random
+import sys
 from functools import lru_cache
 from ipaddress import IPv4Address, IPv6Address, _BaseAddress, ip_address
 from typing import TYPE_CHECKING, Dict, List, Optional, Set, Union, cast
@@ -78,12 +79,15 @@
 # the A/AAAA/SRV records for a host.
 _AVOID_SYNC_DELAY_RANDOM_INTERVAL = (20, 120)
 
+bytes_ = bytes
 float_ = float
 int_ = int
 
 DNS_QUESTION_TYPE_QU = DNSQuestionType.QU
 DNS_QUESTION_TYPE_QM = DNSQuestionType.QM
 
+IPADDRESS_SUPPORTS_SCOPE_ID = sys.version_info >= (3, 9, 0)
+
 if TYPE_CHECKING:
     from .._core import Zeroconf
 
@@ -110,6 +114,29 @@ def _cached_ip_addresses(address: Union[str, bytes, int]) -> Optional[Union[IPv4
 _cached_ip_addresses_wrapper = _cached_ip_addresses
 
 
+def _get_ip_address_object_from_record(record: DNSAddress) -> Optional[Union[IPv4Address, IPv6Address]]:
+    """Get the IP address object from the record."""
+    if IPADDRESS_SUPPORTS_SCOPE_ID and record.type == _TYPE_AAAA and record.scope_id is not None:
+        return _ip_bytes_and_scope_to_address(record.address, record.scope_id)
+    return _cached_ip_addresses_wrapper(record.address)
+
+
+def _ip_bytes_and_scope_to_address(address: bytes_, scope: int_) -> Optional[Union[IPv4Address, IPv6Address]]:
+    """Convert the bytes and scope to an IP address object."""
+    base_address = _cached_ip_addresses_wrapper(address)
+    if base_address is not None and base_address.is_link_local:
+        return _cached_ip_addresses_wrapper(f"{base_address}%{scope}")
+    return base_address
+
+
+def _str_without_scope_id(addr: Union[IPv4Address, IPv6Address]) -> str:
+    """Return the string representation of the address without the scope id."""
+    if IPADDRESS_SUPPORTS_SCOPE_ID and addr.version == 6:
+        address_str = str(addr)
+        return address_str.partition('%')[0]
+    return str(addr)
+
+
 class ServiceInfo(RecordUpdateListener):
     """Service information.
 
@@ -177,6 +204,7 @@ def __init__(
             raise TypeError("addresses and parsed_addresses cannot be provided together")
         if not type_.endswith(service_type_name(name, strict=False)):
             raise BadTypeInNameException
+        self.interface_index = interface_index
         self.text = b''
         self.type = type_
         self._name = name
@@ -199,7 +227,6 @@ def __init__(
             self._set_properties(properties)
         self.host_ttl = host_ttl
         self.other_ttl = other_ttl
-        self.interface_index = interface_index
         self._new_records_futures: Optional[Set[asyncio.Future]] = None
         self._dns_address_cache: Optional[List[DNSAddress]] = None
         self._dns_pointer_cache: Optional[DNSPointer] = None
@@ -243,7 +270,10 @@ def addresses(self, value: List[bytes]) -> None:
         self._get_address_and_nsec_records_cache = None
 
         for address in value:
-            addr = _cached_ip_addresses_wrapper(address)
+            if IPADDRESS_SUPPORTS_SCOPE_ID and len(address) == 16 and self.interface_index is not None:
+                addr = _ip_bytes_and_scope_to_address(address, self.interface_index)
+            else:
+                addr = _cached_ip_addresses_wrapper(address)
             if addr is None:
                 raise TypeError(
                     "Addresses must either be IPv4 or IPv6 strings, bytes, or integers;"
@@ -322,10 +352,10 @@ def ip_addresses_by_version(
 
     def _ip_addresses_by_version_value(
         self, version_value: int_
-    ) -> Union[List[IPv4Address], List[IPv6Address], List[_BaseAddress]]:
+    ) -> Union[List[IPv4Address], List[IPv6Address]]:
         """Backend for addresses_by_version that uses the raw value."""
         if version_value == _IPVersion_All_value:
-            return [*self._ipv4_addresses, *self._ipv6_addresses]
+            return [*self._ipv4_addresses, *self._ipv6_addresses]  # type: ignore[return-value]
         if version_value == _IPVersion_V4Only_value:
             return self._ipv4_addresses
         return self._ipv6_addresses
@@ -339,7 +369,7 @@ def parsed_addresses(self, version: IPVersion = IPVersion.All) -> List[str]:
         This means the first address will always be the most recently added
         address of the given IP version.
         """
-        return [str(addr) for addr in self._ip_addresses_by_version_value(version.value)]
+        return [_str_without_scope_id(addr) for addr in self._ip_addresses_by_version_value(version.value)]
 
     def parsed_scoped_addresses(self, version: IPVersion = IPVersion.All) -> List[str]:
         """Equivalent to parsed_addresses, with the exception that IPv6 Link-Local
@@ -351,12 +381,7 @@ def parsed_scoped_addresses(self, version: IPVersion = IPVersion.All) -> List[st
         This means the first address will always be the most recently added
         address of the given IP version.
         """
-        if self.interface_index is None:
-            return self.parsed_addresses(version)
-        return [
-            f"{addr}%{self.interface_index}" if addr.version == 6 and addr.is_link_local else str(addr)
-            for addr in self._ip_addresses_by_version_value(version.value)
-        ]
+        return [str(addr) for addr in self._ip_addresses_by_version_value(version.value)]
 
     def _set_properties(self, properties: Dict[Union[str, bytes], Optional[Union[str, bytes]]]) -> None:
         """Sets properties and text of this info from a dictionary"""
@@ -421,8 +446,8 @@ def _get_ip_addresses_from_cache_lifo(
         for record in self._get_address_records_from_cache_by_type(zc, type):
             if record.is_expired(now):
                 continue
-            ip_addr = _cached_ip_addresses_wrapper(record.address)
-            if ip_addr is not None:
+            ip_addr = _get_ip_address_object_from_record(record)
+            if ip_addr is not None and ip_addr not in address_list:
                 address_list.append(ip_addr)
         address_list.reverse()  # Reverse to get LIFO order
         return address_list
@@ -471,7 +496,7 @@ def _process_record_threadsafe(self, zc: 'Zeroconf', record: DNSRecord, now: flo
             dns_address_record = record
             if TYPE_CHECKING:
                 assert isinstance(dns_address_record, DNSAddress)
-            ip_addr = _cached_ip_addresses_wrapper(dns_address_record.address)
+            ip_addr = _get_ip_address_object_from_record(dns_address_record)
             if ip_addr is None:
                 log.warning(
                     "Encountered invalid address while processing %s: %s",

tests/services/test_info.py

@@ -7,6 +7,7 @@
 import logging
 import os
 import socket
+import sys
 import threading
 import unittest
 from ipaddress import ip_address
@@ -538,6 +539,7 @@ def test_multiple_addresses():
     assert info.addresses == [address, address]
     assert info.parsed_addresses() == [address_parsed, address_parsed]
     assert info.parsed_scoped_addresses() == [address_parsed, address_parsed]
+    ipaddress_supports_scope_id = sys.version_info >= (3, 9, 0)
 
     if has_working_ipv6() and not os.environ.get('SKIP_IPV6'):
         address_v6_parsed = "2001:db8::1"
@@ -576,30 +578,79 @@ def test_multiple_addresses():
             assert info.ip_addresses_by_version(r.IPVersion.All) == [
                 ip_address(address),
                 ip_address(address_v6),
-                ip_address(address_v6_ll),
+                ip_address(address_v6_ll_scoped_parsed)
+                if ipaddress_supports_scope_id
+                else ip_address(address_v6_ll),
             ]
             assert info.addresses_by_version(r.IPVersion.V4Only) == [address]
             assert info.ip_addresses_by_version(r.IPVersion.V4Only) == [ip_address(address)]
             assert info.addresses_by_version(r.IPVersion.V6Only) == [address_v6, address_v6_ll]
             assert info.ip_addresses_by_version(r.IPVersion.V6Only) == [
                 ip_address(address_v6),
-                ip_address(address_v6_ll),
+                ip_address(address_v6_ll_scoped_parsed)
+                if ipaddress_supports_scope_id
+                else ip_address(address_v6_ll),
             ]
             assert info.parsed_addresses() == [address_parsed, address_v6_parsed, address_v6_ll_parsed]
             assert info.parsed_addresses(r.IPVersion.V4Only) == [address_parsed]
             assert info.parsed_addresses(r.IPVersion.V6Only) == [address_v6_parsed, address_v6_ll_parsed]
             assert info.parsed_scoped_addresses() == [
                 address_parsed,
                 address_v6_parsed,
-                address_v6_ll_scoped_parsed,
+                address_v6_ll_scoped_parsed if ipaddress_supports_scope_id else address_v6_ll_parsed,
             ]
             assert info.parsed_scoped_addresses(r.IPVersion.V4Only) == [address_parsed]
             assert info.parsed_scoped_addresses(r.IPVersion.V6Only) == [
                 address_v6_parsed,
-                address_v6_ll_scoped_parsed,
+                address_v6_ll_scoped_parsed if ipaddress_supports_scope_id else address_v6_ll_parsed,
             ]
 
 
+@unittest.skipIf(sys.version_info < (3, 9, 0), 'Requires newer python')
+def test_scoped_addresses_from_cache():
+    type_ = "_http._tcp.local."
+    registration_name = f"scoped.{type_}"
+    zeroconf = r.Zeroconf(interfaces=['127.0.0.1'])
+    host = "scoped.local."
+
+    zeroconf.cache.async_add_records(
+        [
+            r.DNSPointer(
+                type_,
+                const._TYPE_PTR,
+                const._CLASS_IN | const._CLASS_UNIQUE,
+                120,
+                registration_name,
+            ),
+            r.DNSService(
+                registration_name,
+                const._TYPE_SRV,
+                const._CLASS_IN | const._CLASS_UNIQUE,
+                120,
+                0,
+                0,
+                80,
+                host,
+            ),
+            r.DNSAddress(
+                host,
+                const._TYPE_AAAA,
+                const._CLASS_IN | const._CLASS_UNIQUE,
+                120,
+                socket.inet_pton(socket.AF_INET6, "fe80::52e:c2f2:bc5f:e9c6"),
+                scope_id=12,
+            ),
+        ]
+    )
+
+    # New kwarg way
+    info = ServiceInfo(type_, registration_name)
+    info.load_from_cache(zeroconf)
+    assert info.parsed_scoped_addresses() == ["fe80::52e:c2f2:bc5f:e9c6%12"]
+    assert info.ip_addresses_by_version(r.IPVersion.V6Only) == [ip_address("fe80::52e:c2f2:bc5f:e9c6%12")]
+    zeroconf.close()
+
+
 # This test uses asyncio because it needs to access the cache directly
 # which is not threadsafe
 @pytest.mark.asyncio