**DO NOT MERGE** Set sensible COAP timeouts for sleepy thread devices

aiohomekit/controller/coap/connection.py

@@ -27,6 +27,7 @@
 from aiocoap import Context, Message, resource
 from aiocoap.error import NetworkError
 from aiocoap.numbers.codes import Code
+from aiocoap.numbers.constants import TransportTuning
 from cryptography.exceptions import InvalidTag
 from cryptography.hazmat.primitives.ciphers.aead import ChaCha20Poly1305
 
@@ -78,7 +79,7 @@ class EncryptionContext:
     send_ctr: int
     send_ctx: ChaCha20Poly1305
 
-    def __init__(self, recv_ctx, send_ctx, event_ctx, uri, coap_ctx):
+    def __init__(self, recv_ctx, send_ctx, event_ctx, uri, coap_ctx, transport_tuning):
         self.recv_ctr = 0
         self.recv_ctx = recv_ctx
         self.send_ctr = 0
@@ -89,6 +90,7 @@ def __init__(self, recv_ctx, send_ctx, event_ctx, uri, coap_ctx):
         self.coap_ctx = coap_ctx
         self.lock = asyncio.Lock()
         self.uri = uri
+        self._transport_tuning = transport_tuning
 
     def decrypt(self, enc_data: bytes) -> bytes:
         logger.debug("DECRYPT counter=%d" % (self.recv_ctr,))
@@ -166,7 +168,12 @@ async def post_bytes(self, payload: bytes, timeout: int = 16.0):
             payload = self.encrypt(payload)
 
             try:
-                request = Message(code=Code.POST, payload=payload, uri=self.uri)
+                request = Message(
+                    code=Code.POST,
+                    payload=payload,
+                    uri=self.uri,
+                    transport_tuning=self._transport_tuning,
+                )
                 async with asyncio_timeout(timeout):
                     response = await self.coap_ctx.request(request).response
             except (NetworkError, asyncio.TimeoutError):
@@ -257,6 +264,35 @@ def __init__(self, owner, host, port):
         self.enc_ctx = None
         self.owner = owner
         self.pair_setup_client = None
+        self._transport_tuning = TransportTuning()
+
+    def set_interval(self, interval: int) -> None:
+        """
+        Configure a connection's CoAP parameters based on how sleepy it is.
+
+        We don't expect the interval to change frequently at runtime, maybe it would on e.g. a firmware update.
+        We also don't expect a device to go from sleeping to not sleeping - if its battery powered its sleepy for a reason.
+        """
+        if not interval:
+            # Devicce is not sleepy, don't do anything
+            return
+
+        logger.debug("Setting CoAP parameters for sleep-interval of %d", interval)
+
+        self._transport_tuning.ACK_TIMEOUT = interval / 1000
+
+        # Recalculate these based on new interval
+        self._transport_tuning.MAX_TRANSMIT_SPAN = (
+            self._transport_tuning.ACK_TIMEOUT
+            * (2**self._transport_tuning.MAX_RETRANSMIT - 1)
+            * self._transport_tuning.ACK_RANDOM_FACTOR
+        )
+        self._transport_tuning.MAX_TRANSMIT_WAIT = (
+            self._transport_tuning.ACK_TIMEOUT
+            * (2 ** (self._transport_tuning.MAX_RETRANSMIT + 1) - 1)
+            * self._transport_tuning.ACK_RANDOM_FACTOR
+        )
+        self._transport_tuning.PROCESSING_DELAY = self._transport_tuning.ACK_TIMEOUT
 
     async def reconnect_soon(self):
         if not self.enc_ctx:
@@ -269,7 +305,12 @@ async def do_identify(self):
         client = await Context.create_client_context()
         uri = "coap://%s/0" % (self.address)
 
-        request = Message(code=Code.POST, payload=b"", uri=uri)
+        request = Message(
+            code=Code.POST,
+            payload=b"",
+            uri=uri,
+            transport_tuning=self._transport_tuning,
+        )
         async with asyncio_timeout(4.0):
             response = await client.request(request).response
 
@@ -288,7 +329,12 @@ async def do_pair_setup(self, with_auth):
         while True:
             try:
                 payload = TLV.encode_list(request)
-                request = Message(code=Code.POST, payload=payload, uri=uri)
+                request = Message(
+                    code=Code.POST,
+                    payload=payload,
+                    uri=uri,
+                    transport_tuning=self._transport_tuning,
+                )
                 # some operations can take some time
                 async with asyncio_timeout(16.0):
                     response = await self.pair_setup_client.request(request).response
@@ -312,7 +358,12 @@ async def do_pair_setup_finish(self, pin, salt, srpB):
         while True:
             try:
                 payload = TLV.encode_list(request)
-                request = Message(code=Code.POST, payload=payload, uri=uri)
+                request = Message(
+                    code=Code.POST,
+                    payload=payload,
+                    uri=uri,
+                    transport_tuning=self._transport_tuning,
+                )
                 async with asyncio_timeout(16.0):
                     response = await self.pair_setup_client.request(request).response
 
@@ -350,7 +401,12 @@ async def do_pair_verify(self, pairing_data):
         while True:
             try:
                 payload = TLV.encode_list(request)
-                request = Message(code=Code.POST, payload=payload, uri=uri)
+                request = Message(
+                    code=Code.POST,
+                    payload=payload,
+                    uri=uri,
+                    transport_tuning=self._transport_tuning,
+                )
                 async with asyncio_timeout(8.0):
                     response = await coap_client.request(request).response
 
@@ -377,7 +433,7 @@ async def do_pair_verify(self, pairing_data):
         uri = "coap://%s/" % (self.address)
 
         self.enc_ctx = EncryptionContext(
-            recv_ctx, send_ctx, event_ctx, uri, coap_client
+            recv_ctx, send_ctx, event_ctx, uri, coap_client, self._transport_tuning
         )
 
         logger.debug(f"Connected to CoAP HAP accessory at {self.address}!")

aiohomekit/controller/coap/pairing.py

@@ -24,7 +24,11 @@
 from aiohomekit.controller.abstract import AbstractController, AbstractPairingData
 from aiohomekit.exceptions import AccessoryDisconnectedError
 from aiohomekit.model import Accessories, AccessoriesState, Transport
-from aiohomekit.model.characteristics import CharacteristicPermissions
+from aiohomekit.model.characteristics import (
+    CharacteristicPermissions,
+    CharacteristicsTypes,
+)
+from aiohomekit.model.services import ServicesTypes
 from aiohomekit.protocol.statuscodes import HapStatusCode
 from aiohomekit.utils import async_create_task
 from aiohomekit.uuid import normalize_uuid
@@ -48,6 +52,32 @@ def __init__(
 
         super().__init__(controller, pairing_data)
 
+    def _load_accessories_from_cache(self) -> None:
+        super()._load_accessories_from_cache()
+        self._set_interval_from_accessory_state()
+
+    def restore_accessories_state(
+        self,
+        accessories: list[dict[str, Any]],
+        config_num: int,
+        broadcast_key: bytes | None,
+    ) -> None:
+        super().restore_accessories_state(accessories, config_num, broadcast_key)
+        self._set_interval_from_accessory_state()
+
+    def _set_interval_from_accessory_state(self):
+        """
+        Tune the CoAP connection based on metadata in the accessory
+        runtime information service.
+        """
+        if service := self.accessories.aid(1).services.first(
+            service_type=ServicesTypes.ACCESSORY_RUNTIME_INFORMATION
+        ):
+            if interval := service.characteristics.first(
+                CharacteristicsTypes.SLEEP_INTERVAL
+            ):
+                self.connection.set_interval(interval.value + 1)
+
     def _async_endpoint_changed(self) -> None:
         """The IP/Port has changed, so close connection if active then reconnect."""
         self.connection.address = (

pyproject.toml

@@ -23,7 +23,7 @@ python = "^3.10"
 cryptography = ">=2.9.2"
 zeroconf = ">=0.128.4"
 commentjson = "^0.9.0"
-aiocoap = ">=0.4.5"
+aiocoap = ">=0.4.7"
 bleak = ">=0.19.0"
 chacha20poly1305-reuseable = ">=0.12.1"
 bleak-retry-connector = ">=2.9.0"