Add missing binary input functions (#574)

* bi.c: add possibility to set custom object names

Add an array of MAX_BINARY_INPUTS values containing the custom object
names.

When calling Binary_Input_Object_Name, if no custom name has been set,
return a string with the object type and the object instance number.
Otherwise, return the custom object name.

When setting the object name, first check that the string is not NULL,
then set the name in the new array.

Signed-off-by: Sebastian Weyer <sebastian.weyer@smile.fr>

* bi.c: add possibility to set custom description

Implement functions Binary_Input_Description and
Binary_Input_Description_Set. Binary_Input_Description will return an
empty string if no custom description has been set yet.

In order to store the custom descriptions, we declare a new array with
MAX_BINARY_INPUTS amount of values.

When setting a new description using Binary_Input_Description_Set, we
first check that the new description is not NULL and then store it in
array at the object_instance position.

In the Binary_Input_Read_Property function, we need to split
PROP_DESCRIPTION from PROP_OBJECT_NAME in the switch case as before the
object name would be returned when the description was being read by a
client. Now we properly call Binary_Input_Description.

Signed-off-by: Sebastian Weyer <sebastian.weyer@smile.fr>

---------

Signed-off-by: Sebastian Weyer <sebastian.weyer@smile.fr>
Co-authored-by: Sebastian Weyer <sebastian.weyer@smile.fr>

src/bacnet/basic/object/bi.c

@@ -51,6 +51,10 @@ static bool Out_Of_Service[MAX_BINARY_INPUTS];
 static bool Change_Of_Value[MAX_BINARY_INPUTS];
 /* Polarity of Input */
 static BACNET_POLARITY Polarity[MAX_BINARY_INPUTS];
+/* stores the object name */
+static char* Object_Name[MAX_BINARY_INPUTS];
+/* stores the description */
+static char* Description[MAX_BINARY_INPUTS];
 
 /* These three arrays are used by the ReadPropertyMultiple handler */
 static const int Binary_Input_Properties_Required[] = { PROP_OBJECT_IDENTIFIER,
@@ -294,9 +298,32 @@ bool Binary_Input_Object_Name(
 
     index = Binary_Input_Instance_To_Index(object_instance);
     if (index < MAX_BINARY_INPUTS) {
-        sprintf(
-            text_string, "BINARY INPUT %lu", (unsigned long)object_instance);
-        status = characterstring_init_ansi(object_name, text_string);
+        if (Object_Name[index] == NULL) {
+            sprintf(
+                text_string, "BINARY INPUT %lu", (unsigned long)object_instance);
+            status = characterstring_init_ansi(object_name, text_string);
+        } else {
+            status = characterstring_init_ansi(object_name, Object_Name[index]);
+        }
+    }
+
+    return status;
+}
+
+/**
+ * For a given object instance-number, sets the object-name
+ *
+ * @param  object_instance - object-instance number of the object
+ * @param  new_name - holds the object-name to be set
+ *
+ * @return  true if object-name was set
+ */
+bool Binary_Input_Name_Set(uint32_t object_instance, char *new_name)
+{
+    bool status = false;
+    if (object_instance < MAX_BINARY_INPUTS && new_name) {
+        status = true;
+        Object_Name[object_instance] = new_name;
     }
 
     return status;
@@ -329,6 +356,44 @@ bool Binary_Input_Polarity_Set(
     return status;
 }
 
+/**
+ * @brief For a given object instance-number, returns the description
+ * @param  object_instance - object-instance number of the object
+ * @return description text or NULL if not found
+ */
+char *Binary_Input_Description(uint32_t object_instance)
+{
+    char *name = NULL;
+
+    if (object_instance < MAX_BINARY_INPUTS) {
+        if (Description[object_instance] == NULL) {
+            name = "";
+        } else {
+            name = Description[object_instance];
+        }
+    }
+
+    return name;
+}
+
+/**
+ * @brief For a given object instance-number, sets the description
+ * @param  object_instance - object-instance number of the object
+ * @param  new_name - holds the description to be set
+ * @return  true if object-name was set
+ */
+bool Binary_Input_Description_Set(uint32_t object_instance, char *new_name)
+{
+    bool status = false; /* return value */
+
+    if (object_instance < MAX_BINARY_INPUTS && new_name) {
+        status = true;
+        Description[object_instance] = new_name;
+    }
+
+    return status;
+}
+
 /* return apdu length, or BACNET_STATUS_ERROR on error */
 /* assumption - object already exists, and has been bounds checked */
 int Binary_Input_Read_Property(BACNET_READ_PROPERTY_DATA *rpdata)
@@ -350,12 +415,17 @@ int Binary_Input_Read_Property(BACNET_READ_PROPERTY_DATA *rpdata)
                 &apdu[0], OBJECT_BINARY_INPUT, rpdata->object_instance);
             break;
         case PROP_OBJECT_NAME:
-        case PROP_DESCRIPTION:
             /* note: object name must be unique in our device */
             Binary_Input_Object_Name(rpdata->object_instance, &char_string);
             apdu_len =
                 encode_application_character_string(&apdu[0], &char_string);
             break;
+        case PROP_DESCRIPTION:
+            characterstring_init_ansi(&char_string,
+                Binary_Input_Description(rpdata->object_instance));
+            apdu_len =
+                encode_application_character_string(&apdu[0], &char_string);
+            break;
         case PROP_OBJECT_TYPE:
             apdu_len =
                 encode_application_enumerated(&apdu[0], OBJECT_BINARY_INPUT);