Fix various zeroconf IPv6 compatibility issues (#53505)

homeassistant/components/zeroconf/__init__.py

@@ -150,14 +150,21 @@ async def async_setup(hass: HomeAssistant, config: dict) -> bool:
             if not adapter["enabled"]:
                 continue
             if ipv4s := adapter["ipv4"]:
-                interfaces.append(ipv4s[0]["address"])
+                interfaces.extend(
-            elif ipv6s := adapter["ipv6"]:
+                    ipv4["address"]
-                interfaces.append(ipv6s[0]["scope_id"])
+                    for ipv4 in ipv4s
+                    if not ipaddress.ip_address(ipv4["address"]).is_loopback
+                )
+            if adapter["ipv6"]:
+                ifi = socket.if_nametoindex(adapter["name"])
+                interfaces.append(ifi)
 
     ipv6 = True
     if not any(adapter["enabled"] and adapter["ipv6"] for adapter in adapters):
         ipv6 = False
         zc_args["ip_version"] = IPVersion.V4Only
+    else:
+        zc_args["ip_version"] = IPVersion.All
 
     aio_zc = await _async_get_instance(hass, **zc_args)
     zeroconf = cast(HaZeroconf, aio_zc.zeroconf)
@@ -190,6 +197,32 @@ async def async_setup(hass: HomeAssistant, config: dict) -> bool:
     return True
 
 
+def _get_announced_addresses(
+    adapters: list[Adapter],
+    first_ip: bytes | None = None,
+) -> list[bytes]:
+    """Return a list of IP addresses to announce via zeroconf.
+
+    If first_ip is not None, it will be the first address in the list.
+    """
+    addresses = {
+        addr.packed
+        for addr in [
+            ipaddress.ip_address(ip["address"])
+            for adapter in adapters
+            if adapter["enabled"]
+            for ip in cast(list, adapter["ipv6"]) + cast(list, adapter["ipv4"])
+        ]
+        if not (addr.is_unspecified or addr.is_loopback)
+    }
+    if first_ip:
+        address_list = [first_ip]
+        address_list.extend(addresses - set({first_ip}))
+    else:
+        address_list = list(addresses)
+    return address_list
+
+
 async def _async_register_hass_zc_service(
     hass: HomeAssistant, aio_zc: HaAsyncZeroconf, uuid: str
 ) -> None:
@@ -218,12 +251,15 @@ async def _async_register_hass_zc_service(
     # Set old base URL based on external or internal
     params["base_url"] = params["external_url"] or params["internal_url"]
 
-    host_ip = await async_get_source_ip(hass, target_ip=MDNS_TARGET_IP)
+    adapters = await network.async_get_adapters(hass)
 
-    try:
+    # Puts the default IPv4 address first in the list to preserve compatibility,
+    # because some mDNS implementations ignores anything but the first announced address.
+    host_ip = await async_get_source_ip(hass, target_ip=MDNS_TARGET_IP)
+    host_ip_pton = None
+    if host_ip:
         host_ip_pton = socket.inet_pton(socket.AF_INET, host_ip)
-    except OSError:
+    address_list = _get_announced_addresses(adapters, host_ip_pton)
-        host_ip_pton = socket.inet_pton(socket.AF_INET6, host_ip)
 
     _suppress_invalid_properties(params)
 
@@ -231,7 +267,7 @@ async def _async_register_hass_zc_service(
         ZEROCONF_TYPE,
         name=f"{valid_location_name}.{ZEROCONF_TYPE}",
         server=f"{uuid}.local.",
-        addresses=[host_ip_pton],
+        addresses=address_list,
         port=hass.http.server_port,
         properties=params,
     )

tests/components/zeroconf/test_init.py

@@ -1,11 +1,16 @@
 """Test Zeroconf component setup process."""
+from ipaddress import ip_address
 from unittest.mock import call, patch
 
 from zeroconf import InterfaceChoice, IPVersion, ServiceStateChange
 from zeroconf.asyncio import AsyncServiceInfo
 
 from homeassistant.components import zeroconf
-from homeassistant.components.zeroconf import CONF_DEFAULT_INTERFACE, CONF_IPV6
+from homeassistant.components.zeroconf import (
+    CONF_DEFAULT_INTERFACE,
+    CONF_IPV6,
+    _get_announced_addresses,
+)
 from homeassistant.const import (
     EVENT_HOMEASSISTANT_START,
     EVENT_HOMEASSISTANT_STARTED,
@@ -726,10 +731,16 @@ _ADAPTERS_WITH_MANUAL_CONFIG = [
         "ipv6": [
             {
                 "address": "2001:db8::",
-                "network_prefix": 8,
+                "network_prefix": 64,
                 "flowinfo": 1,
                 "scope_id": 1,
-            }
+            },
+            {
+                "address": "fe80::1234:5678:9abc:def0",
+                "network_prefix": 64,
+                "flowinfo": 1,
+                "scope_id": 1,
+            },
         ],
         "name": "eth0",
     },
@@ -741,6 +752,21 @@ _ADAPTERS_WITH_MANUAL_CONFIG = [
         "ipv6": [],
         "name": "eth1",
     },
+    {
+        "auto": True,
+        "default": False,
+        "enabled": True,
+        "ipv4": [{"address": "172.16.1.5", "network_prefix": 23}],
+        "ipv6": [
+            {
+                "address": "fe80::dead:beef:dead:beef",
+                "network_prefix": 64,
+                "flowinfo": 1,
+                "scope_id": 3,
+            }
+        ],
+        "name": "eth2",
+    },
     {
         "auto": False,
         "default": False,
@@ -764,9 +790,36 @@ async def test_async_detect_interfaces_setting_empty_route(hass, mock_async_zero
     ), patch(
         "homeassistant.components.zeroconf.AsyncServiceInfo",
         side_effect=get_service_info_mock,
+    ), patch(
+        "socket.if_nametoindex",
+        side_effect=lambda iface: {"eth0": 1, "eth1": 2, "eth2": 3, "vtun0": 4}.get(
+            iface, 0
+        ),
     ):
         assert await async_setup_component(hass, zeroconf.DOMAIN, {zeroconf.DOMAIN: {}})
         hass.bus.async_fire(EVENT_HOMEASSISTANT_STARTED)
         await hass.async_block_till_done()
+    assert mock_zc.mock_calls[0] == call(
+        interfaces=[1, "192.168.1.5", "172.16.1.5", 3], ip_version=IPVersion.All
+    )
 
-    assert mock_zc.mock_calls[0] == call(interfaces=[1, "192.168.1.5"])
+
+async def test_get_announced_addresses(hass, mock_async_zeroconf):
+    """Test addresses for mDNS announcement."""
+    expected = {
+        ip_address(ip).packed
+        for ip in [
+            "fe80::1234:5678:9abc:def0",
+            "2001:db8::",
+            "192.168.1.5",
+            "fe80::dead:beef:dead:beef",
+            "172.16.1.5",
+        ]
+    }
+    first_ip = ip_address("172.16.1.5").packed
+    actual = _get_announced_addresses(_ADAPTERS_WITH_MANUAL_CONFIG, first_ip)
+    assert actual[0] == first_ip and set(actual) == expected
+
+    first_ip = ip_address("192.168.1.5").packed
+    actual = _get_announced_addresses(_ADAPTERS_WITH_MANUAL_CONFIG, first_ip)
+    assert actual[0] == first_ip and set(actual) == expected