"""Support for exposing Home Assistant via Zeroconf.""" from __future__ import annotations import asyncio import contextlib from contextlib import suppress from dataclasses import dataclass from fnmatch import translate from functools import lru_cache from ipaddress import IPv4Address, IPv6Address, ip_address import logging import re import socket import sys from typing import Any, Final, cast import voluptuous as vol from zeroconf import ( BadTypeInNameException, InterfaceChoice, IPVersion, ServiceStateChange, ) from zeroconf.asyncio import AsyncServiceInfo from homeassistant import config_entries from homeassistant.components import network from homeassistant.components.network import MDNS_TARGET_IP, async_get_source_ip from homeassistant.components.network.models import Adapter from homeassistant.const import EVENT_HOMEASSISTANT_STOP, __version__ from homeassistant.core import Event, HomeAssistant, callback from homeassistant.data_entry_flow import BaseServiceInfo from homeassistant.helpers import discovery_flow, instance_id import homeassistant.helpers.config_validation as cv from homeassistant.helpers.network import NoURLAvailableError, get_url from homeassistant.helpers.typing import ConfigType from homeassistant.loader import ( HomeKitDiscoveredIntegration, async_get_homekit, async_get_zeroconf, bind_hass, ) from homeassistant.setup import async_when_setup_or_start from .models import HaAsyncServiceBrowser, HaAsyncZeroconf, HaZeroconf from .usage import install_multiple_zeroconf_catcher _LOGGER = logging.getLogger(__name__) DOMAIN = "zeroconf" ZEROCONF_TYPE = "_home-assistant._tcp.local." HOMEKIT_TYPES = [ "_hap._tcp.local.", # Thread based devices "_hap._udp.local.", ] # Top level keys we support matching against in properties that are always matched in # lower case. ex: ZeroconfServiceInfo.name LOWER_MATCH_ATTRS = {"name"} CONF_DEFAULT_INTERFACE = "default_interface" CONF_IPV6 = "ipv6" DEFAULT_DEFAULT_INTERFACE = True DEFAULT_IPV6 = True HOMEKIT_PAIRED_STATUS_FLAG = "sf" HOMEKIT_MODEL = "md" # Property key=value has a max length of 255 # so we use 230 to leave space for key= MAX_PROPERTY_VALUE_LEN = 230 # Dns label max length MAX_NAME_LEN = 63 ATTR_PROPERTIES: Final = "properties" # Attributes for ZeroconfServiceInfo[ATTR_PROPERTIES] ATTR_PROPERTIES_ID: Final = "id" CONFIG_SCHEMA = vol.Schema( { DOMAIN: vol.All( cv.deprecated(CONF_DEFAULT_INTERFACE), cv.deprecated(CONF_IPV6), vol.Schema( { vol.Optional(CONF_DEFAULT_INTERFACE): cv.boolean, vol.Optional(CONF_IPV6, default=DEFAULT_IPV6): cv.boolean, } ), ) }, extra=vol.ALLOW_EXTRA, ) @dataclass(slots=True) class ZeroconfServiceInfo(BaseServiceInfo): """Prepared info from mDNS entries.""" host: str addresses: list[str] port: int | None hostname: str type: str name: str properties: dict[str, Any] @bind_hass async def async_get_instance(hass: HomeAssistant) -> HaZeroconf: """Zeroconf instance to be shared with other integrations that use it.""" return cast(HaZeroconf, (await _async_get_instance(hass)).zeroconf) @bind_hass async def async_get_async_instance(hass: HomeAssistant) -> HaAsyncZeroconf: """Zeroconf instance to be shared with other integrations that use it.""" return await _async_get_instance(hass) async def _async_get_instance(hass: HomeAssistant, **zcargs: Any) -> HaAsyncZeroconf: if DOMAIN in hass.data: return cast(HaAsyncZeroconf, hass.data[DOMAIN]) logging.getLogger("zeroconf").setLevel(logging.NOTSET) zeroconf = HaZeroconf(**zcargs) aio_zc = HaAsyncZeroconf(zc=zeroconf) install_multiple_zeroconf_catcher(zeroconf) async def _async_stop_zeroconf(_event: Event) -> None: """Stop Zeroconf.""" await aio_zc.ha_async_close() hass.bus.async_listen_once(EVENT_HOMEASSISTANT_STOP, _async_stop_zeroconf) hass.data[DOMAIN] = aio_zc return aio_zc @callback def _async_zc_has_functional_dual_stack() -> bool: """Return true for platforms not supporting IP_ADD_MEMBERSHIP on an AF_INET6 socket. Zeroconf only supports a single listen socket at this time. """ return not sys.platform.startswith("freebsd") and not sys.platform.startswith( "darwin" ) async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool: """Set up Zeroconf and make Home Assistant discoverable.""" zc_args: dict = {"ip_version": IPVersion.V4Only} adapters = await network.async_get_adapters(hass) ipv6 = False if _async_zc_has_functional_dual_stack(): if any(adapter["enabled"] and adapter["ipv6"] for adapter in adapters): ipv6 = True zc_args["ip_version"] = IPVersion.All elif not any(adapter["enabled"] and adapter["ipv4"] for adapter in adapters): zc_args["ip_version"] = IPVersion.V6Only ipv6 = True if not ipv6 and network.async_only_default_interface_enabled(adapters): zc_args["interfaces"] = InterfaceChoice.Default else: zc_args["interfaces"] = [ str(source_ip) for source_ip in await network.async_get_enabled_source_ips(hass) if not source_ip.is_loopback and not (isinstance(source_ip, IPv6Address) and source_ip.is_global) and not ( isinstance(source_ip, IPv6Address) and zc_args["ip_version"] == IPVersion.V4Only ) and not ( isinstance(source_ip, IPv4Address) and zc_args["ip_version"] == IPVersion.V6Only ) ] aio_zc = await _async_get_instance(hass, **zc_args) zeroconf = cast(HaZeroconf, aio_zc.zeroconf) zeroconf_types, homekit_models = await asyncio.gather( async_get_zeroconf(hass), async_get_homekit(hass) ) discovery = ZeroconfDiscovery(hass, zeroconf, zeroconf_types, homekit_models, ipv6) await discovery.async_setup() async def _async_zeroconf_hass_start(hass: HomeAssistant, comp: str) -> None: """Expose Home Assistant on zeroconf when it starts. Wait till started or otherwise HTTP is not up and running. """ uuid = await instance_id.async_get(hass) await _async_register_hass_zc_service(hass, aio_zc, uuid) async def _async_zeroconf_hass_stop(_event: Event) -> None: await discovery.async_stop() hass.bus.async_listen_once(EVENT_HOMEASSISTANT_STOP, _async_zeroconf_hass_stop) async_when_setup_or_start(hass, "frontend", _async_zeroconf_hass_start) 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 [ 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 def _filter_disallowed_characters(name: str) -> str: """Filter disallowed characters from a string. . is a reversed character for zeroconf. """ return name.replace(".", " ") async def _async_register_hass_zc_service( hass: HomeAssistant, aio_zc: HaAsyncZeroconf, uuid: str ) -> None: # Get instance UUID valid_location_name = _truncate_location_name_to_valid( _filter_disallowed_characters(hass.config.location_name or "Home") ) params = { "location_name": valid_location_name, "uuid": uuid, "version": __version__, "external_url": "", "internal_url": "", # Old base URL, for backward compatibility "base_url": "", # Always needs authentication "requires_api_password": True, } # Get instance URL's with suppress(NoURLAvailableError): params["external_url"] = get_url(hass, allow_internal=False) with suppress(NoURLAvailableError): params["internal_url"] = get_url(hass, allow_external=False) # Set old base URL based on external or internal params["base_url"] = params["external_url"] or params["internal_url"] adapters = await network.async_get_adapters(hass) # 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) address_list = _get_announced_addresses(adapters, host_ip_pton) _suppress_invalid_properties(params) info = AsyncServiceInfo( ZEROCONF_TYPE, name=f"{valid_location_name}.{ZEROCONF_TYPE}", server=f"{uuid}.local.", addresses=address_list, port=hass.http.server_port, properties=params, ) _LOGGER.info("Starting Zeroconf broadcast") await aio_zc.async_register_service(info, allow_name_change=True) def _match_against_data( matcher: dict[str, str | dict[str, str]], match_data: dict[str, str] ) -> bool: """Check a matcher to ensure all values in match_data match.""" for key in LOWER_MATCH_ATTRS: if key not in matcher: continue if key not in match_data: return False match_val = matcher[key] assert isinstance(match_val, str) if not _memorized_fnmatch(match_data[key], match_val): return False return True def _match_against_props(matcher: dict[str, str], props: dict[str, str]) -> bool: """Check a matcher to ensure all values in props.""" return not any( key for key in matcher if key not in props or not _memorized_fnmatch(props[key].lower(), matcher[key]) ) def is_homekit_paired(props: dict[str, Any]) -> bool: """Check properties to see if a device is homekit paired.""" if HOMEKIT_PAIRED_STATUS_FLAG not in props: return False with contextlib.suppress(ValueError): # 0 means paired and not discoverable by iOS clients) return int(props[HOMEKIT_PAIRED_STATUS_FLAG]) == 0 # If we cannot tell, we assume its not paired return False class ZeroconfDiscovery: """Discovery via zeroconf.""" def __init__( self, hass: HomeAssistant, zeroconf: HaZeroconf, zeroconf_types: dict[str, list[dict[str, str | dict[str, str]]]], homekit_models: dict[str, HomeKitDiscoveredIntegration], ipv6: bool, ) -> None: """Init discovery.""" self.hass = hass self.zeroconf = zeroconf self.zeroconf_types = zeroconf_types self.homekit_models = homekit_models self.ipv6 = ipv6 self.async_service_browser: HaAsyncServiceBrowser | None = None async def async_setup(self) -> None: """Start discovery.""" types = list(self.zeroconf_types) # We want to make sure we know about other HomeAssistant # instances as soon as possible to avoid name conflicts # so we always browse for ZEROCONF_TYPE for hk_type in (ZEROCONF_TYPE, *HOMEKIT_TYPES): if hk_type not in self.zeroconf_types: types.append(hk_type) _LOGGER.debug("Starting Zeroconf browser for: %s", types) self.async_service_browser = HaAsyncServiceBrowser( self.ipv6, self.zeroconf, types, handlers=[self.async_service_update] ) async def async_stop(self) -> None: """Cancel the service browser and stop processing the queue.""" if self.async_service_browser: await self.async_service_browser.async_cancel() def _async_dismiss_discoveries(self, name: str) -> None: """Dismiss all discoveries for the given name.""" for flow in self.hass.config_entries.flow.async_progress_by_init_data_type( ZeroconfServiceInfo, lambda service_info: bool(service_info.name == name), ): self.hass.config_entries.flow.async_abort(flow["flow_id"]) @callback def async_service_update( self, zeroconf: HaZeroconf, service_type: str, name: str, state_change: ServiceStateChange, ) -> None: """Service state changed.""" _LOGGER.debug( "service_update: type=%s name=%s state_change=%s", service_type, name, state_change, ) if state_change == ServiceStateChange.Removed: self._async_dismiss_discoveries(name) return try: async_service_info = AsyncServiceInfo(service_type, name) except BadTypeInNameException as ex: # Some devices broadcast a name that is not a valid DNS name # This is a bug in the device firmware and we should ignore it _LOGGER.debug("Bad name in zeroconf record: %s: %s", name, ex) return if async_service_info.load_from_cache(zeroconf): self._async_process_service_update(async_service_info, service_type, name) else: self.hass.async_create_task( self._async_lookup_and_process_service_update( zeroconf, async_service_info, service_type, name ) ) async def _async_lookup_and_process_service_update( self, zeroconf: HaZeroconf, async_service_info: AsyncServiceInfo, service_type: str, name: str, ) -> None: """Update and process a zeroconf update.""" await async_service_info.async_request(zeroconf, 3000) self._async_process_service_update(async_service_info, service_type, name) @callback def _async_process_service_update( self, async_service_info: AsyncServiceInfo, service_type: str, name: str ) -> None: """Process a zeroconf update.""" info = info_from_service(async_service_info) if not info: # Prevent the browser thread from collapsing _LOGGER.debug("Failed to get addresses for device %s", name) return _LOGGER.debug("Discovered new device %s %s", name, info) props: dict[str, str] = info.properties domain = None # If we can handle it as a HomeKit discovery, we do that here. if service_type in HOMEKIT_TYPES and ( homekit_model := async_get_homekit_discovery_domain( self.homekit_models, props ) ): domain = homekit_model.domain discovery_flow.async_create_flow( self.hass, homekit_model.domain, {"source": config_entries.SOURCE_HOMEKIT}, info, ) # Continue on here as homekit_controller # still needs to get updates on devices # so it can see when the 'c#' field is updated. # # We only send updates to homekit_controller # if the device is already paired in order to avoid # offering a second discovery for the same device if not is_homekit_paired(props) and not homekit_model.always_discover: # If the device is paired with HomeKit we must send on # the update to homekit_controller so it can see when # the 'c#' field is updated. This is used to detect # when the device has been reset or updated. # # If the device is not paired and we should not always # discover it, we can stop here. return match_data: dict[str, str] = {} for key in LOWER_MATCH_ATTRS: attr_value: str = getattr(info, key) match_data[key] = attr_value.lower() # Not all homekit types are currently used for discovery # so not all service type exist in zeroconf_types for matcher in self.zeroconf_types.get(service_type, []): if len(matcher) > 1: if not _match_against_data(matcher, match_data): continue if ATTR_PROPERTIES in matcher: matcher_props = matcher[ATTR_PROPERTIES] assert isinstance(matcher_props, dict) if not _match_against_props(matcher_props, props): continue matcher_domain = matcher["domain"] assert isinstance(matcher_domain, str) context = { "source": config_entries.SOURCE_ZEROCONF, } if domain: # Domain of integration that offers alternative API to handle # this device. context["alternative_domain"] = domain discovery_flow.async_create_flow( self.hass, matcher_domain, context, info, ) def async_get_homekit_discovery_domain( homekit_models: dict[str, HomeKitDiscoveredIntegration], props: dict[str, Any] ) -> HomeKitDiscoveredIntegration | None: """Handle a HomeKit discovery. Return the domain to forward the discovery data to """ model = None for key in props: if key.lower() == HOMEKIT_MODEL: model = props[key] break if model is None: return None for test_model in homekit_models: if ( model != test_model and not model.startswith((f"{test_model} ", f"{test_model}-")) and not _memorized_fnmatch(model, test_model) ): continue return homekit_models[test_model] return None def info_from_service(service: AsyncServiceInfo) -> ZeroconfServiceInfo | None: """Return prepared info from mDNS entries.""" properties: dict[str, Any] = {"_raw": {}} for key, value in service.properties.items(): # See https://ietf.org/rfc/rfc6763.html#section-6.4 and # https://ietf.org/rfc/rfc6763.html#section-6.5 for expected encodings # for property keys and values try: key = key.decode("ascii") except UnicodeDecodeError: _LOGGER.debug( "Ignoring invalid key provided by [%s]: %s", service.name, key ) continue properties["_raw"][key] = value with suppress(UnicodeDecodeError): if isinstance(value, bytes): properties[key] = value.decode("utf-8") if not (ip_addresses := service.ip_addresses_by_version(IPVersion.All)): return None host: str | None = None for ip_addr in ip_addresses: if not ip_addr.is_link_local and not ip_addr.is_unspecified: host = str(ip_addr) break if not host: return None assert service.server is not None, "server cannot be none if there are addresses" return ZeroconfServiceInfo( host=host, addresses=[str(ip_addr) for ip_addr in ip_addresses], port=service.port, hostname=service.server, type=service.type, name=service.name, properties=properties, ) def _suppress_invalid_properties(properties: dict) -> None: """Suppress any properties that will cause zeroconf to fail to startup.""" for prop, prop_value in properties.items(): if not isinstance(prop_value, str): continue if len(prop_value.encode("utf-8")) > MAX_PROPERTY_VALUE_LEN: _LOGGER.error( ( "The property '%s' was suppressed because it is longer than the" " maximum length of %d bytes: %s" ), prop, MAX_PROPERTY_VALUE_LEN, prop_value, ) properties[prop] = "" def _truncate_location_name_to_valid(location_name: str) -> str: """Truncate or return the location name usable for zeroconf.""" if len(location_name.encode("utf-8")) < MAX_NAME_LEN: return location_name _LOGGER.warning( ( "The location name was truncated because it is longer than the maximum" " length of %d bytes: %s" ), MAX_NAME_LEN, location_name, ) return location_name.encode("utf-8")[:MAX_NAME_LEN].decode("utf-8", "ignore") @lru_cache(maxsize=4096, typed=True) def _compile_fnmatch(pattern: str) -> re.Pattern: """Compile a fnmatch pattern.""" return re.compile(translate(pattern)) @lru_cache(maxsize=1024, typed=True) def _memorized_fnmatch(name: str, pattern: str) -> bool: """Memorized version of fnmatch that has a larger lru_cache. The default version of fnmatch only has a lru_cache of 256 entries. With many devices we quickly reach that limit and end up compiling the same pattern over and over again. Zeroconf has its own memorized fnmatch with its own lru_cache since the data is going to be relatively the same since the devices will not change frequently """ return bool(_compile_fnmatch(pattern).match(name))