Add defensive checks against unexpected schedule responses (#305)

Add defensive checks against unexpected schedule responses. I do not yet
know the valid version of responses for this command, so for now it
seems best to just check for out of bounds messages and assume that the
schedules are not supported. This can be revisited as we capture traces
for these devices.

For home-assistant/home-assistant.io#29766

pyrainbird/rainbird.py

@@ -36,6 +36,8 @@ def decode_schedule(data: str, cmd_template: dict[str, Any]) -> dict[str, Any]:
     subcommand = int(data[4:6], 16)
     rest = data[6:]
     if subcommand == 0:
+        if len(rest) < 8:
+            return {}
         # Delay, Snooze, Rainsensor
         return {
             "controllerInfo": {
@@ -46,6 +48,8 @@ def decode_schedule(data: str, cmd_template: dict[str, Any]) -> dict[str, Any]:
         }
 
     if subcommand & 16 == 16:
+        if len(rest) < 10:
+            return {}
         program = subcommand & ~16
         fields = list(int(rest[i : i + 2], 16) for i in range(0, len(rest), 2))
         return {
@@ -61,6 +65,8 @@ def decode_schedule(data: str, cmd_template: dict[str, Any]) -> dict[str, Any]:
         }
 
     if subcommand & 96 == 96:
+        if len(rest) < 4:
+            return {}
         program = subcommand & ~96
         # Note: 65535 is disabled
         entries = list(int(rest[i : i + 4], 16) for i in range(0, len(rest), 4))
@@ -72,6 +78,8 @@ def decode_schedule(data: str, cmd_template: dict[str, Any]) -> dict[str, Any]:
         }
 
     if subcommand & 128 == 128:
+        if len(rest) < 4:
+            return {}
         station = subcommand & ~128
         rest = bytes(data[6:], "utf-8")
         durations = list(int(rest[i : i + 4], 16) for i in range(0, len(rest), 4))

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = pyrainbird
-version = 4.0.0
+version = 4.0.1
 description = Rain Bird Controller
 long_description = file: README.md
 long_description_content_type = text/markdown

tests/test_async_client.py

@@ -1271,3 +1271,43 @@ async def test_custom_schedule_in_past(
         datetime.datetime(2023, 1, 30, 4, 0, 0),
         datetime.datetime(2023, 2, 5, 4, 0, 0),
     ]
+
+
+
+@freeze_time("2023-01-25 20:00:00")
+async def test_get_schedule_parse_failure(
+    rainbird_controller: Callable[[], Awaitable[AsyncRainbirdController]],
+    api_response: Callable[[...], Awaitable[None]],
+    sip_data_responses: Callable[[list[str]], None],
+) -> None:
+    """Test a schedule that fails to parse."""
+    controller = await rainbird_controller()
+
+    api_response("82", modelID=0x0A, protocolRevisionMajor=1, protocolRevisionMinor=3)
+    api_response("83", pageNumber=1, setStations=0x1F000000)  # 5 stations
+    sip_data_responses(
+        [
+            "A0000080",
+            "A00010",
+            "A00011",
+            "A00012",
+            "A00060",
+            "A00061",
+            "A00062",
+            "A00080",
+            "A00081",
+            "A00082",
+            "A00083",
+            "A00084",
+            "A00085",
+            "A00086",
+            "A00087",
+            "A00088",
+            "A00089",
+            "A00080",
+            "A0008A",
+        ]
+    )
+
+    schedule = await controller.get_schedule()
+    assert len(schedule.programs) == 0