Handle the case where Device ID is BACNET_MAX_INSTANCE: for RP and RPM, put the real device ID in the response.

bacnet-stack/src/rpm.c

@@ -108,6 +108,14 @@ int rpm_encode_apdu_object_end(
     return apdu_len;
 }
 
+/** Encode an RPM request, to be sent.
+ * 
+ * @param apdu [in,out] Buffer to hold encoded bytes.
+ * @param max_apdu [in] Length of apdu buffer.
+ * @param invoke_id [in] The Invoke ID to use for this message.
+ * @param read_access_data [in] The RPM data to be requested.
+ * @return Length of encoded bytes, or 0 on failure.
+ */
 int rpm_encode_apdu(
     uint8_t * apdu,
     size_t max_apdu,
@@ -328,12 +336,18 @@ int rpm_ack_encode_apdu_object_begin(
     BACNET_RPM_DATA * rpmdata)
 {
     int apdu_len = 0;   /* total length of the apdu, return value */
+    uint32_t obj_instance = rpmdata->object_instance;
 
     if (apdu) {
+        /* Test for case of indefinite Device object instance */
+        if ( (rpmdata->object_type == OBJECT_DEVICE) && 
+        	 (obj_instance == BACNET_MAX_INSTANCE) )
+        	obj_instance = Device_Object_Instance_Number();
+
         /* Tag 0: objectIdentifier */
         apdu_len =
             encode_context_object_id(&apdu[0], 0, rpmdata->object_type,
-            rpmdata->object_instance);
+            		obj_instance);
         /* Tag 1: listOfResults */
         apdu_len += encode_opening_tag(&apdu[apdu_len], 1);
     }