Reading 8- or 16-bit attributes from big-endian device returns 0 (#6166)

project-chip · Apr 20, 2021 · de63682 · de63682
1 parent f3ec8e6
commit de63682
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Showing 3 changed files with 38 additions and 7 deletions.
diff --git a/src/app/util/af-types.h b/src/app/util/af-types.h
@@ -88,6 +88,37 @@ typedef void (*EmberAfGenericClusterFunction)(void);
  */
 #define EMBER_AF_NULL_MANUFACTURER_CODE 0x0000
 
+/**
+ * @brief Type for align a 16 bits value.
+ *
+ * This structure has the same size as a pointer and is used to align
+ * a 16 bit value to the 16 least significant bits of a pointer.
+ * Note that this structure is aware of the endianess and the pointer size.
+ */
+typedef struct
+{
+#if (BIGENDIAN_CPU)
+#if (UINTPTR_MAX == UINT32_MAX)
+    uint32_t align : 16;
+#elif (UINTPTR_MAX == UINT64_MAX)
+    uint64_t align : 48;
+#endif
+#endif
+
+    /**
+     * Actual value.
+     */
+    uint16_t value;
+
+#if (!BIGENDIAN_CPU)
+#if (UINTPTR_MAX == UINT32_MAX)
+    uint32_t align : 16;
+#elif (UINTPTR_MAX == UINT64_MAX)
+    uint64_t align : 48;
+#endif
+#endif
+} EmberAfAlignValue;
+
 /**
  * @brief Type for default values.
  *
@@ -106,7 +137,7 @@ typedef union
     /**
      * Actual default value if the attribute size is 2 bytes or less.
      */
-    uint16_t defaultValue;
+    EmberAfAlignValue defaultValue;
 } EmberAfDefaultAttributeValue;
 
 /**
@@ -143,9 +174,9 @@ typedef union
      */
     uint8_t * ptrToDefaultValue;
     /**
-     * Actual default value if the attribute size is 2 bytes or less.
+     * Default value of the attribute.
      */
-    uint16_t defaultValue;
+    EmberAfAlignValue defaultValue;
     /**
      * Points to the min max attribute value structure, if min/max is
      * supported for this attribute.

diff --git a/src/app/util/attribute-storage.cpp b/src/app/util/attribute-storage.cpp
@@ -1088,7 +1088,7 @@ void emAfLoadAttributeDefaults(EndpointId endpoint, bool writeTokens)
                     {
                         if (emberAfAttributeSize(am) <= 2)
                         {
-                            ptr = (uint8_t *) &(am->defaultValue.ptrToMinMaxValue->defaultValue.defaultValue);
+                            ptr = (uint8_t *) &(am->defaultValue.ptrToMinMaxValue->defaultValue.defaultValue.value);
                         }
                         else
                         {
@@ -1099,7 +1099,7 @@ void emAfLoadAttributeDefaults(EndpointId endpoint, bool writeTokens)
                     {
                         if (emberAfAttributeSize(am) <= 2)
                         {
-                            ptr = (uint8_t *) &(am->defaultValue.defaultValue);
+                            ptr = (uint8_t *) &(am->defaultValue.defaultValue.value);
                         }
                         else
                         {

diff --git a/src/app/util/attribute-table.cpp b/src/app/util/attribute-table.cpp
@@ -536,8 +536,8 @@ EmberAfStatus emAfWriteAttribute(EndpointId endpoint, ClusterId cluster, Attribu
         if (dataLen <= 2)
         {
             int8_t minR, maxR;
-            uint8_t * minI = (uint8_t *) &(minv.defaultValue);
-            uint8_t * maxI = (uint8_t *) &(maxv.defaultValue);
+            uint8_t * minI = (uint8_t *) &(minv.defaultValue.value);
+            uint8_t * maxI = (uint8_t *) &(maxv.defaultValue.value);
 // On big endian cpu with length 1 only the second byte counts
 #if (BIGENDIAN_CPU)
             if (dataLen == 1)