Added bypass in basic WriteProperty handler to accept writes of NULL to non-commandable properties (#919)

2025-03-10 07:30:55 -05:00
parent 7e725ce028
commit 4ee129e249
9 changed files with 253 additions and 8 deletions
@@ -487,3 +487,60 @@ bool write_property_unsigned_decode(

    return status;
 }
+
+/**
+ * @brief Handler for a WriteProperty Service request when the
+ *  property is a NULL type and the property is not commandable
+ *
+ *      15.9.2 WriteProperty Service Procedure
+ *
+ *      If an attempt is made to relinquish a property that is
+ *      not commandable and for which Null is not a supported
+ *      datatype, if no other error conditions exist,
+ *      the property shall not be changed, and the write shall
+ *      be considered successful.
+ *
+ * @param wp_data [in] The WriteProperty data structure
+ * @param member_of_object [in] Function to check if a property is a member
+  of an object instance
+ * @return true if the write shall be considered successful
+ */
+bool write_property_relinquish_bypass(
+    BACNET_WRITE_PROPERTY_DATA *wp_data,
+    write_property_member_of_object member_of_object)
+{
+    bool bypass = false;
+    bool has_priority_array = false;
+    int len = 0;
+
+    if (!wp_data) {
+        return false;
+    }
+    len = bacnet_null_application_decode(
+        wp_data->application_data, wp_data->application_data_len);
+    if ((len > 0) && (len == wp_data->application_data_len)) {
+        /* single NULL */
+        /* check to see if this object property is commandable.
+           Does the property list contain a priority-array? */
+        if (member_of_object) {
+            has_priority_array = member_of_object(
+                wp_data->object_type, wp_data->object_instance,
+                PROP_PRIORITY_ARRAY);
+        }
+        if (has_priority_array || (wp_data->object_type == OBJECT_CHANNEL)) {
+            if (wp_data->object_property != PROP_PRESENT_VALUE) {
+                /* this property is not commandable,
+                   so it "shall not be changed, and
+                   the write shall be considered successful." */
+                bypass = true;
+            }
+        } else {
+            /* this object is not commandable, so any property
+               written with a NULL "shall not be changed, and
+               the write shall be considered successful." */
+            bypass = true;
+        }
+    }
+
+    return bypass;
+}