From 7ac05110ca57f6af6d3a201ce07388b4c3ab1cee Mon Sep 17 00:00:00 2001
From: jan iversen <jan@casacondor.com>
Date: Sun, 2 May 2021 00:03:52 +0200
Subject: [PATCH] Catch non payload modbus messages (#49910)

---
 homeassistant/components/modbus/modbus.py | 40 +++++++++--------------
 1 file changed, 16 insertions(+), 24 deletions(-)

diff --git a/homeassistant/components/modbus/modbus.py b/homeassistant/components/modbus/modbus.py
index f04c019e6a6..c1fbe7a9eb7 100644
--- a/homeassistant/components/modbus/modbus.py
+++ b/homeassistant/components/modbus/modbus.py
@@ -5,7 +5,6 @@ import threading
 from pymodbus.client.sync import ModbusSerialClient, ModbusTcpClient, ModbusUdpClient
 from pymodbus.constants import Defaults
 from pymodbus.exceptions import ModbusException
-from pymodbus.pdu import ExceptionResponse, IllegalFunctionRequest
 from pymodbus.transaction import ModbusRtuFramer
 
 from homeassistant.const import (
@@ -237,8 +236,8 @@ class ModbusHub:
                 result = self._client.read_coils(address, count, **kwargs)
             except ModbusException as exception_error:
                 self._log_error(exception_error)
-                return None
-            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                result = exception_error
+            if not hasattr(result, "registers"):
                 self._log_error(result)
                 return None
             self._in_error = False
@@ -251,9 +250,8 @@ class ModbusHub:
             try:
                 result = self._client.read_discrete_inputs(address, count, **kwargs)
             except ModbusException as exception_error:
-                self._log_error(exception_error)
-                return None
-            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                result = exception_error
+            if not hasattr(result, "registers"):
                 self._log_error(result)
                 return None
             self._in_error = False
@@ -266,9 +264,8 @@ class ModbusHub:
             try:
                 result = self._client.read_input_registers(address, count, **kwargs)
             except ModbusException as exception_error:
-                self._log_error(exception_error)
-                return None
-            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                result = exception_error
+            if not hasattr(result, "registers"):
                 self._log_error(result)
                 return None
             self._in_error = False
@@ -281,9 +278,8 @@ class ModbusHub:
             try:
                 result = self._client.read_holding_registers(address, count, **kwargs)
             except ModbusException as exception_error:
-                self._log_error(exception_error)
-                return None
-            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                result = exception_error
+            if not hasattr(result, "registers"):
                 self._log_error(result)
                 return None
             self._in_error = False
@@ -296,9 +292,8 @@ class ModbusHub:
             try:
                 result = self._client.write_coil(address, value, **kwargs)
             except ModbusException as exception_error:
-                self._log_error(exception_error)
-                return False
-            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                result = exception_error
+            if not hasattr(result, "registers"):
                 self._log_error(result)
                 return False
             self._in_error = False
@@ -311,9 +306,8 @@ class ModbusHub:
             try:
                 result = self._client.write_coils(address, values, **kwargs)
             except ModbusException as exception_error:
-                self._log_error(exception_error)
-                return False
-            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                result = exception_error
+            if not hasattr(result, "registers"):
                 self._log_error(result)
                 return False
             self._in_error = False
@@ -326,9 +320,8 @@ class ModbusHub:
             try:
                 result = self._client.write_register(address, value, **kwargs)
             except ModbusException as exception_error:
-                self._log_error(exception_error)
-                return False
-            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                result = exception_error
+            if not hasattr(result, "registers"):
                 self._log_error(result)
                 return False
             self._in_error = False
@@ -341,9 +334,8 @@ class ModbusHub:
             try:
                 result = self._client.write_registers(address, values, **kwargs)
             except ModbusException as exception_error:
-                self._log_error(exception_error)
-                return False
-            if isinstance(result, (ExceptionResponse, IllegalFunctionRequest)):
+                result = exception_error
+            if not hasattr(result, "registers"):
                 self._log_error(result)
                 return False
             self._in_error = False