- IED server: Implemented read/write access control to RCBs (LIB61850-391)

examples/server_example_access_control/server_example_access_control.c

@@ -75,6 +75,17 @@ connectionHandler (IedServer self, ClientConnection connection, bool connected,
         printf("Connection closed\n");
 }
 
+/*
+ * This handler is called before the rcbEventHandler and can be use to allow or permit read or write access to the RCB
+ */
+bool
+rcbAccessHandler(void* parameter, ReportControlBlock* rcb, ClientConnection connection, IedServer_RCBEventType operation)
+{
+    printf("RCB: %s access: %s\n", ReportControlBlock_getName(rcb), operation == RCB_EVENT_GET_PARAMETER ? "READ" : "WRITE");
+
+    return false;
+}
+
 static void
 rcbEventHandler(void* parameter, ReportControlBlock* rcb, ClientConnection connection, IedServer_RCBEventType event, const char* parameterName, MmsDataAccessError serviceError)
 {
@@ -167,6 +178,8 @@ main(int argc, char** argv)
 
     IedServer_setConnectionIndicationHandler(iedServer, (IedConnectionIndicationHandler) connectionHandler, NULL);
 
+    IedServer_setRCBAccessHandler(iedServer, rcbAccessHandler, NULL);
+
     IedServer_setRCBEventHandler(iedServer, rcbEventHandler, NULL);
 
     /* By default access to variables with FC=DC and FC=CF is not allowed.

src/iec61850/inc/iec61850_server.h

@@ -1622,6 +1622,30 @@ typedef void (*IedServer_RCBEventHandler) (void* parameter, ReportControlBlock*
 LIB61850_API void
 IedServer_setRCBEventHandler(IedServer self, IedServer_RCBEventHandler handler, void* parameter);
 
+
+/**
+ * \brief Callback that is called in case of RCB access to give the user the opportunity to block or allow the operation
+ * 
+ * \note This callback is called before the IedServer_RCBEventHandler and only in case of operations (RCB_EVENT_GET_PARAMETER, RCB_EVENT_SET_PARAMETER, RCB_EVENT_ENABLE
+ * 
+ * \param parameter user provided parameter
+ * \param rcb affected report control block
+ * \param connection client connection that is involved
+ * \param operation one of the following operation event types: RCB_EVENT_GET_PARAMETER, RCB_EVENT_SET_PARAMETER
+ */
+typedef bool
+(*IedServer_RCBAccessHandler) (void* parameter, ReportControlBlock* rcb, ClientConnection connection, IedServer_RCBEventType operation);
+
+/**
+ * \brief Set a handler to control read and write access to report control blocks (RCBs)
+ *
+ * \param self the instance of IedServer to operate on.
+ * \param handler the event handler to be used
+ * \param parameter a user provided parameter that is passed to the handler.
+ */
+LIB61850_API void
+IedServer_setRCBAccessHandler(IedServer self, IedServer_RCBAccessHandler handler, void* parameter);
+
 /**@}*/
 
 /**

src/iec61850/inc_private/mms_mapping_internal.h

@@ -335,6 +335,9 @@ struct sMmsMapping {
     IedServer_RCBEventHandler rcbEventHandler;
     void* rcbEventHandlerParameter;
 
+    IedServer_RCBAccessHandler rcbAccessHandler;
+    void* rcbAccessHandlerParameter;
+
     IedServer_DataSetAccessHandler dataSetAccessHandler;
     void* dataSetAccessHandlerParameter;
 };

src/iec61850/inc_private/reporting.h

@@ -140,7 +140,7 @@ LIB61850_INTERNAL MmsDataAccessError
 Reporting_RCBWriteAccessHandler(MmsMapping* self, ReportControl* rc, char* elementName, MmsValue* value,
         MmsServerConnection connection);
 
-LIB61850_INTERNAL void
+LIB61850_INTERNAL bool
 ReportControl_readAccess(ReportControl* rc, MmsMapping* mmsMapping, MmsServerConnection connection, char* elementName);
 
 LIB61850_INTERNAL void

src/iec61850/server/impl/ied_server.c

@@ -689,6 +689,13 @@ IedServer_setRCBEventHandler(IedServer self, IedServer_RCBEventHandler handler,
     self->mmsMapping->rcbEventHandlerParameter = parameter;
 }
 
+void
+IedServer_setRCBAccessHandler(IedServer self, IedServer_RCBAccessHandler handler, void* parameter)
+{
+    self->mmsMapping->rcbAccessHandler = handler;
+    self->mmsMapping->rcbAccessHandlerParameter = parameter;
+}
+
 void
 IedServer_destroy(IedServer self)
 {

src/iec61850/server/mms_mapping/reporting.c

@@ -1697,21 +1697,35 @@ checkReservationTimeout(MmsMapping* self, ReportControl* rc)
     }
 }
 
-void
+bool
 ReportControl_readAccess(ReportControl* rc, MmsMapping* mmsMapping, MmsServerConnection connection, char* elementName)
 {
-    (void)elementName;
+    bool accessAllowed = true;
+    MmsDataAccessError accessError = DATA_ACCESS_ERROR_SUCCESS;
 
     /* check reservation timeout */
     if (rc->buffered) {
         checkReservationTimeout(mmsMapping, rc);
     }
 
-    if (mmsMapping->rcbEventHandler) {
-        ClientConnection clientConnection = private_IedServer_getClientConnectionByHandle(mmsMapping->iedServer, connection);
+    ClientConnection clientConnection = NULL;
+
+    if (mmsMapping->rcbAccessHandler || mmsMapping->rcbEventHandler) {
+        clientConnection = private_IedServer_getClientConnectionByHandle(mmsMapping->iedServer, connection);
+    }
+
+    if (mmsMapping->rcbAccessHandler) {
+        if (mmsMapping->rcbAccessHandler(mmsMapping->rcbAccessHandlerParameter, rc->rcb, clientConnection, RCB_EVENT_GET_PARAMETER) == false) {
+            accessError = DATA_ACCESS_ERROR_OBJECT_ACCESS_DENIED;
+            accessAllowed = false;
+        }
+    }
 
-        mmsMapping->rcbEventHandler(mmsMapping->rcbEventHandlerParameter, rc->rcb, clientConnection, RCB_EVENT_GET_PARAMETER, elementName, DATA_ACCESS_ERROR_SUCCESS);
+    if (mmsMapping->rcbEventHandler) {
+        mmsMapping->rcbEventHandler(mmsMapping->rcbEventHandlerParameter, rc->rcb, clientConnection, RCB_EVENT_GET_PARAMETER, elementName, accessError);
     }
+
+    return accessAllowed;
 }
 
 static bool
@@ -1809,6 +1823,15 @@ Reporting_RCBWriteAccessHandler(MmsMapping* self, ReportControl* rc, char* eleme
 
     ClientConnection clientConnection = private_IedServer_getClientConnectionByHandle(self->iedServer, connection);
 
+    /* check if write access to RCB is allowed on this connection */
+    if (self->rcbAccessHandler) {
+        if (self->rcbAccessHandler(self->rcbAccessHandlerParameter, rc->rcb, clientConnection, RCB_EVENT_SET_PARAMETER) == false) {
+            retVal = DATA_ACCESS_ERROR_OBJECT_ACCESS_DENIED;
+
+            goto exit_function_only_tracking;
+        }
+    }
+
     /* check reservation timeout for buffered RCBs */
     if (rc->buffered) {
 
@@ -2491,6 +2514,8 @@ exit_function:
 
     ReportControl_unlockNotify(rc);
 
+exit_function_only_tracking:
+
 #if (CONFIG_IEC61850_SERVICE_TRACKING == 1)
     if (rc->buffered)
         updateGenericTrackingObjectValues(self, rc, IEC61850_SERVICE_TYPE_SET_BRCB_VALUES, retVal);