From a81bbd4de05065d267e3c48e20d741d2b8e0a7f2 Mon Sep 17 00:00:00 2001
From: puddly <32534428+puddly@users.noreply.github.com>
Date: Thu, 5 Dec 2024 13:46:34 -0500
Subject: [PATCH] Fix XNCP parsing for hacked LIDL gateway (#657)

---
 bellows/ezsp/xncp.py |  6 ++++++
 tests/test_xncp.py   | 14 ++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/bellows/ezsp/xncp.py b/bellows/ezsp/xncp.py
index ca9da4dd..d50f0575 100644
--- a/bellows/ezsp/xncp.py
+++ b/bellows/ezsp/xncp.py
@@ -67,6 +67,12 @@ def from_payload(cls, payload: XncpCommandPayload) -> XncpCommand:
     def from_bytes(cls, data: bytes) -> XncpCommand:
         command_id, data = XncpCommandId.deserialize(data)
         status, data = EmberStatus.deserialize(data)
+
+        if command_id not in COMMANDS:
+            raise ValueError(
+                f"Unknown XNCP command ID: 0x{command_id:04X} (payload {data!r})"
+            )
+
         payload, rest = COMMANDS[command_id].deserialize(data)
 
         if rest:
diff --git a/tests/test_xncp.py b/tests/test_xncp.py
index 61f5b7df..23aa846c 100644
--- a/tests/test_xncp.py
+++ b/tests/test_xncp.py
@@ -48,6 +48,20 @@ async def test_xncp_failure_multiprotocol(ezsp_f: EZSP) -> None:
     ]
 
 
+async def test_xncp_failure_lidl(ezsp_f: EZSP) -> None:
+    """Test XNCP failure with hacked LIDL gateway."""
+    ezsp_f._mock_commands["customFrame"] = customFrame = AsyncMock(
+        return_value=[t.EmberStatus.SUCCESS, b"\x00\x01\x03"]
+    )
+
+    with pytest.raises(InvalidCommandError):
+        await ezsp_f.xncp_get_supported_firmware_features()
+
+    assert customFrame.mock_calls == [
+        call(xncp.XncpCommand.from_payload(xncp.GetSupportedFeaturesReq()).serialize())
+    ]
+
+
 async def test_xncp_failure_unknown(ezsp_f: EZSP) -> None:
     """Test XNCP failure, unknown command."""
     ezsp_f._mock_commands["customFrame"] = customFrame = AsyncMock(