python-zeroconf · bdraco · Feb 7, 2024 · Feb 7, 2024 · Feb 7, 2024 · Feb 7, 2024
diff --git a/src/zeroconf/_core.py b/src/zeroconf/_core.py
@@ -162,7 +162,12 @@ def __init__(
             * `InterfaceChoice.All` is an alias for `InterfaceChoice.Default`
               on Python versions before 3.8.
 
+            * `InterfaceChoice.AllWithLoopback` is the same as `InterfaceChoice.All`
+               on POSIX systems, but includes the loopback interfaces. This likely
+               only works on macOS/BSD.
+
             Also listening on loopback (``::1``) doesn't work, use a real address.
+
         :param ip_version: IP versions to support. If `choice` is a list, the default is detected
             from it. Otherwise defaults to V4 only for backward compatibility.
         :param apple_p2p: use AWDL interface (only macOS)

diff --git a/src/zeroconf/_dns.py b/src/zeroconf/_dns.py
@@ -25,7 +25,6 @@
 from typing import TYPE_CHECKING, Any, Dict, List, Optional, Set, Union, cast
 
 from ._exceptions import AbstractMethodException
-from ._utils.net import _is_v6_address
 from ._utils.time import current_time_millis
 from .const import _CLASS_MASK, _CLASS_UNIQUE, _CLASSES, _TYPE_ANY, _TYPES
 

diff --git a/src/zeroconf/_utils/net.py b/src/zeroconf/_utils/net.py
@@ -22,8 +22,8 @@
 
 import enum
 import errno
-import ipaddress
 import socket
+import ipaddress
 import struct
 import sys
 from typing import Any, List, Optional, Sequence, Tuple, Union, cast
@@ -32,12 +32,14 @@
 
 from .._logger import log
 from ..const import _IPPROTO_IPV6, _MDNS_ADDR, _MDNS_ADDR6, _MDNS_PORT
+from .ipaddress import _cached_ip_addresses
 
 
 @enum.unique
 class InterfaceChoice(enum.Enum):
     Default = 1
     All = 2
+    AllWithLoopback = 3
 
 
 InterfacesType = Union[
@@ -62,10 +64,6 @@ class IPVersion(enum.Enum):
 # utility functions
 
 
-def _is_v6_address(addr: bytes) -> bool:
-    return len(addr) == 16
-
-
 def _encode_address(address: str) -> bytes:
     is_ipv6 = ":" in address
     address_family = socket.AF_INET6 if is_ipv6 else socket.AF_INET
@@ -146,7 +144,11 @@ def ip6_addresses_to_indexes(
     for iface in interfaces:
         if isinstance(iface, int):
             result.append((interface_index_to_ip6_address(adapters, iface), iface))
-        elif isinstance(iface, str) and ipaddress.ip_address(iface).version == 6:
+        elif (
+            isinstance(iface, str)
+            and (ip_address := _cached_ip_addresses(iface))
+            and ip_address.version == 6
+        ):
             result.append(ip6_to_address_and_index(adapters, iface))
 
     return result
@@ -169,6 +171,26 @@ def normalize_interface_choice(
         if ip_version != IPVersion.V6Only:
             result.append("0.0.0.0")
     elif choice is InterfaceChoice.All:
+        if ip_version != IPVersion.V4Only:
+            result.extend(
+                ip_tuple
+                for ip_tuple in get_all_addresses_v6()
+                if (ip_address := _cached_ip_addresses(ip_tuple[0][0]))
+                and not ip_address.is_loopback
+            )
+        if ip_version != IPVersion.V6Only:
+            result.extend(
+                ip
+                for ip in get_all_addresses()
+                if (ip_address := _cached_ip_addresses(ip))
+                and not ip_address.is_loopback
+            )
+        if not result:
+            raise RuntimeError(
+                "No interfaces to listen on, check that any interfaces have IP version %s"
+                % ip_version
+            )
+    elif choice is InterfaceChoice.AllWithLoopback:
         if ip_version != IPVersion.V4Only:
             result.extend(get_all_addresses_v6())
         if ip_version != IPVersion.V6Only:

diff --git a/src/zeroconf/asyncio.py b/src/zeroconf/asyncio.py
@@ -161,6 +161,10 @@ def __init__(
             * `InterfaceChoice.All` is an alias for `InterfaceChoice.Default`
               on Python versions before 3.8.
 
+            * `InterfaceChoice.AllWithLoopback` is the same as `InterfaceChoice.All`
+               on POSIX systems, but includes the loopback interfaces. This likely
+               only works on macOS/BSD.
+
             Also listening on loopback (``::1``) doesn't work, use a real address.
         :param ip_version: IP versions to support. If `choice` is a list, the default is detected
             from it. Otherwise defaults to V4 only for backward compatibility.

diff --git a/tests/test_core.py b/tests/test_core.py
@@ -63,21 +63,29 @@ async def make_query():
 
 class Framework(unittest.TestCase):
     def test_launch_and_close(self):
+        rv = r.Zeroconf(interfaces=r.InterfaceChoice.AllWithLoopback)
+        rv.close()
         rv = r.Zeroconf(interfaces=r.InterfaceChoice.All)
         rv.close()
         rv = r.Zeroconf(interfaces=r.InterfaceChoice.Default)
         rv.close()
 
     def test_launch_and_close_context_manager(self):
-        with r.Zeroconf(interfaces=r.InterfaceChoice.All) as rv:
+        with r.Zeroconf(interfaces=r.InterfaceChoice.AllWithLoopback) as rv:
+            assert rv.done is False
+        assert rv.done is True
+
+        with r.Zeroconf(interfaces=r.InterfaceChoice.All) as rv:  # type: ignore[unreachable]
             assert rv.done is False
         assert rv.done is True
 
-        with r.Zeroconf(interfaces=r.InterfaceChoice.Default) as rv:  # type: ignore[unreachable]
+        with r.Zeroconf(interfaces=r.InterfaceChoice.Default) as rv:
             assert rv.done is False
         assert rv.done is True
 
     def test_launch_and_close_unicast(self):
+        rv = r.Zeroconf(interfaces=r.InterfaceChoice.AllWithLoopback, unicast=True)
+        rv.close()
         rv = r.Zeroconf(interfaces=r.InterfaceChoice.All, unicast=True)
         rv.close()
         rv = r.Zeroconf(interfaces=r.InterfaceChoice.Default, unicast=True)
@@ -91,6 +99,10 @@ def test_close_multiple_times(self):
     @unittest.skipIf(not has_working_ipv6(), "Requires IPv6")
     @unittest.skipIf(os.environ.get("SKIP_IPV6"), "IPv6 tests disabled")
     def test_launch_and_close_v4_v6(self):
+        rv = r.Zeroconf(
+            interfaces=r.InterfaceChoice.AllWithLoopback, ip_version=r.IPVersion.All
+        )
+        rv.close()
         rv = r.Zeroconf(interfaces=r.InterfaceChoice.All, ip_version=r.IPVersion.All)
         rv.close()
         rv = r.Zeroconf(
@@ -101,6 +113,10 @@ def test_launch_and_close_v4_v6(self):
     @unittest.skipIf(not has_working_ipv6(), "Requires IPv6")
     @unittest.skipIf(os.environ.get("SKIP_IPV6"), "IPv6 tests disabled")
     def test_launch_and_close_v6_only(self):
+        rv = r.Zeroconf(
+            interfaces=r.InterfaceChoice.AllWithLoopback, ip_version=r.IPVersion.V6Only
+        )
+        rv.close()
         rv = r.Zeroconf(interfaces=r.InterfaceChoice.All, ip_version=r.IPVersion.V6Only)
         rv.close()
         rv = r.Zeroconf(

diff --git a/tests/utils/test_net.py b/tests/utils/test_net.py
@@ -85,12 +85,15 @@ def test_ip6_addresses_to_indexes():
         ]
 
 
-def test_normalize_interface_choice_errors():
+@pytest.mark.parametrize(
+    "interface_choice", (r.InterfaceChoice.All, r.InterfaceChoice.AllWithLoopback)
+)
+def test_normalize_interface_choice_errors(interface_choice: r.InterfaceChoice) -> None:
     """Test we generate exception on invalid input."""
     with patch("zeroconf._utils.net.get_all_addresses", return_value=[]), patch(
         "zeroconf._utils.net.get_all_addresses_v6", return_value=[]
     ), pytest.raises(RuntimeError):
-        netutils.normalize_interface_choice(r.InterfaceChoice.All)
+        netutils.normalize_interface_choice(interface_choice)
 
     with pytest.raises(TypeError):
         netutils.normalize_interface_choice("1.2.3.4")