- IEC 61850 client: add support for single array element access (with component specification)

src/iec61850/client/ied_connection.c

@@ -694,6 +694,34 @@ IedConnection_readObject(IedConnection self, IedClientError* error, const char*
 
     MmsError mmsError;
 
+    /* check if item ID contains an array "(..)" */
+    char* brace = strchr(itemId, '(');
+
+    if (brace) {
+        char* secondBrace = strchr(brace, ')');
+
+        if (secondBrace) {
+            char* endPtr;
+
+            int index = (int) strtol(brace + 1, &endPtr, 10);
+
+            if (endPtr == secondBrace) {
+                char* component = NULL;
+
+                if (strlen(secondBrace + 1) > 1)
+                    component = secondBrace + 2; /* skip "." after array element specifier */
+
+                *brace = 0;
+
+                value = MmsConnection_readSingleArrayElementWithComponent(self->connection, &mmsError, domainId, itemId, index, component);
+            }
+            else
+                *error = IED_ERROR_USER_PROVIDED_INVALID_ARGUMENT;
+        }
+        else
+            *error = IED_ERROR_USER_PROVIDED_INVALID_ARGUMENT;
+    }
+    else
         value = MmsConnection_readVariable(self->connection, &mmsError, domainId, itemId);
 
     if (value != NULL)

src/mms/inc/mms_client_connection.h

@@ -374,7 +374,7 @@ MmsValue*
 MmsConnection_readVariable(MmsConnection self, MmsError* mmsError, const char* domainId, const char* itemId);
 
 /**
- * \brief Read an element of a single array variable from the server.
+ * \brief Read one or more elements of a single array variable from the server.
  *
  * \param self MmsConnection instance to operate on
  * \param mmsError user provided variable to store error code
@@ -391,6 +391,23 @@ MmsValue*
 MmsConnection_readArrayElements(MmsConnection self, MmsError* mmsError, const char* domainId, const char* itemId,
 		uint32_t startIndex, uint32_t numberOfElements);
 
+
+/**
+ * \brief Read a single element (with optional component specification) from the server
+ *
+ * \param self MmsConnection instance to operate on
+ * \param mmsError user provided variable to store error code
+ * \param domainId the domain name of the variable to be read
+ * \param itemId name of the variable to be read
+ * \param index array element index
+ * \param componentId array element component name
+ *
+ * \return Returns a MmsValue object or NULL if the request failed.
+ */
+MmsValue*
+MmsConnection_readSingleArrayElementWithComponent(MmsConnection self, MmsError* mmsError,
+        const char* domainId, const char* itemId, uint32_t index, const char* componentId);
+
 /**
  * \brief Read multiple variables of a domain from the server with one request message.
  *

src/mms/inc_private/mms_client_internal.h

@@ -164,6 +164,10 @@ int
 mmsClient_createReadRequestAlternateAccessIndex(uint32_t invokeId, const char* domainId, const char* itemId,
 		uint32_t index, uint32_t elementCount, ByteBuffer* writeBuffer);
 
+int
+mmsClient_createReadRequestAlternateAccessSingleIndexComponent(uint32_t invokeId, const char* domainId, const char* itemId,
+        uint32_t index, const char* component, ByteBuffer* writeBuffer);
+
 int
 mmsClient_createReadRequestMultipleValues(uint32_t invokeId, const char* domainId, LinkedList /*<char*>*/ items,
 		ByteBuffer* writeBuffer);

src/mms/iso_mms/client/mms_client_connection.c

@@ -1619,6 +1619,35 @@ MmsConnection_readArrayElements(MmsConnection self, MmsError* mmsError,
     return value;
 }
 
+MmsValue*
+MmsConnection_readSingleArrayElementWithComponent(MmsConnection self, MmsError* mmsError,
+        const char* domainId, const char* itemId, uint32_t index, const char* componentId)
+{
+    MmsValue* value = NULL;
+
+    if (getAssociationState(self) != MMS_STATE_CONNECTED) {
+        *mmsError = MMS_ERROR_CONNECTION_LOST;
+        goto exit_function;
+    }
+
+    ByteBuffer* payload = IsoClientConnection_allocateTransmitBuffer(self->isoClient);
+
+    uint32_t invokeId = getNextInvokeId(self);
+
+    mmsClient_createReadRequestAlternateAccessSingleIndexComponent(invokeId, domainId, itemId, index, componentId,
+            payload);
+
+    ByteBuffer* responseMessage = sendRequestAndWaitForResponse(self, invokeId, payload, mmsError);
+
+    if (responseMessage != NULL)
+        value = mmsClient_parseReadResponse(self->lastResponse, NULL, false);
+
+    releaseResponse(self);
+
+exit_function:
+    return value;
+}
+
 MmsValue*
 MmsConnection_readMultipleVariables(MmsConnection self, MmsError* mmsError,
         const char* domainId, LinkedList /*<char*>*/items)

src/mms/iso_mms/client/mms_client_read.c

@@ -461,6 +461,85 @@ createAlternateAccess(uint32_t index, uint32_t elementCount)
     return alternateAccess;
 }
 
+static AlternateAccess_t*
+createAlternateAccessComponent(const char* componentName)
+{
+    AlternateAccess_t* alternateAccess = (AlternateAccess_t*) GLOBAL_CALLOC(1, sizeof(AlternateAccess_t));
+    alternateAccess->list.count = 1;
+    alternateAccess->list.array = (struct AlternateAccess__Member**) GLOBAL_CALLOC(1, sizeof(struct AlternateAccess__Member*));
+    alternateAccess->list.array[0] = (struct AlternateAccess__Member*) GLOBAL_CALLOC(1, sizeof(struct AlternateAccess__Member));
+    alternateAccess->list.array[0]->present = AlternateAccess__Member_PR_unnamed;
+
+    alternateAccess->list.array[0]->choice.unnamed = (AlternateAccessSelection_t*) GLOBAL_CALLOC(1, sizeof(AlternateAccessSelection_t));
+
+    char* separator = strchr(componentName, '$');
+
+    if (separator) {
+        int size = separator - componentName;
+
+        alternateAccess->list.array[0]->choice.unnamed->present = AlternateAccessSelection_PR_selectAlternateAccess;
+        alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.accessSelection.present =
+                AlternateAccessSelection__selectAlternateAccess__accessSelection_PR_component;
+
+        alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.accessSelection.choice.component.buf = (uint8_t*) strndup(componentName, size);
+        alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.accessSelection.choice.component.size = size;
+
+        alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.alternateAccess = createAlternateAccessComponent(separator + 1);
+    }
+    else {
+        int size = strlen(componentName);
+
+        alternateAccess->list.array[0]->choice.unnamed->present = AlternateAccessSelection_PR_selectAccess;
+
+        alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.present =
+                AlternateAccessSelection__selectAccess_PR_component;
+
+        alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.component.buf = (uint8_t*) strndup(componentName, size);
+        alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.component.size = size;
+    }
+
+    return alternateAccess;
+}
+
+static AlternateAccess_t*
+createAlternateAccessIndexComponent(uint32_t index, const char* componentName)
+{
+    AlternateAccess_t* alternateAccess = (AlternateAccess_t*) GLOBAL_CALLOC(1, sizeof(AlternateAccess_t));
+    alternateAccess->list.count = 1;
+    alternateAccess->list.array = (struct AlternateAccess__Member**) GLOBAL_CALLOC(1, sizeof(struct AlternateAccess__Member*));
+    alternateAccess->list.array[0] = (struct AlternateAccess__Member*) GLOBAL_CALLOC(1, sizeof(struct AlternateAccess__Member));
+    alternateAccess->list.array[0]->present = AlternateAccess__Member_PR_unnamed;
+
+    alternateAccess->list.array[0]->choice.unnamed = (AlternateAccessSelection_t*) GLOBAL_CALLOC(1, sizeof(AlternateAccessSelection_t));
+
+    if (componentName) {
+        alternateAccess->list.array[0]->choice.unnamed->present = AlternateAccessSelection_PR_selectAlternateAccess;
+
+        alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.accessSelection.present =
+                AlternateAccessSelection__selectAlternateAccess__accessSelection_PR_index;
+
+        INTEGER_t* asnIndex =
+                &(alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.index);
+
+        asn_long2INTEGER(asnIndex, index);
+
+        alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.alternateAccess = createAlternateAccessComponent(componentName);
+    }
+    else {
+        alternateAccess->list.array[0]->choice.unnamed->present = AlternateAccessSelection_PR_selectAccess;
+
+        alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.present =
+                        AlternateAccessSelection__selectAccess_PR_index;
+
+        INTEGER_t* asnIndex =
+                &(alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.index);
+
+        asn_long2INTEGER(asnIndex, index);
+    }
+
+    return alternateAccess;
+}
+
 static ListOfVariableSeq_t*
 createVariableIdentifier(const char* domainId, const char* itemId)
 {
@@ -511,6 +590,41 @@ mmsClient_createReadRequestAlternateAccessIndex(uint32_t invokeId, const char* d
     return rval.encoded;
 }
 
+int
+mmsClient_createReadRequestAlternateAccessSingleIndexComponent(uint32_t invokeId, const char* domainId, const char* itemId,
+        uint32_t index, const char* component, ByteBuffer* writeBuffer)
+{
+    MmsPdu_t* mmsPdu = mmsClient_createConfirmedRequestPdu(invokeId);
+    ReadRequest_t* readRequest = createReadRequest(mmsPdu);
+
+    readRequest->specificationWithResult = NULL;
+
+    readRequest->variableAccessSpecification.present = VariableAccessSpecification_PR_listOfVariable;
+
+    readRequest->variableAccessSpecification.choice.listOfVariable.list.array = (ListOfVariableSeq_t**) GLOBAL_CALLOC(1, sizeof(ListOfVariableSeq_t*));
+    readRequest->variableAccessSpecification.choice.listOfVariable.list.count = 1;
+
+    ListOfVariableSeq_t* variableIdentifier = createVariableIdentifier(domainId, itemId);
+
+    readRequest->variableAccessSpecification.choice.listOfVariable.list.array[0] = variableIdentifier;
+
+    variableIdentifier->alternateAccess = createAlternateAccessIndexComponent(index, component);
+
+    asn_enc_rval_t rval;
+
+    rval = der_encode(&asn_DEF_MmsPdu, mmsPdu,
+            (asn_app_consume_bytes_f*) mmsClient_write_out, (void*) writeBuffer);
+
+    variableIdentifier->variableSpecification.choice.name.choice.domainspecific.domainId.buf = 0;
+    variableIdentifier->variableSpecification.choice.name.choice.domainspecific.domainId.size = 0;
+    variableIdentifier->variableSpecification.choice.name.choice.domainspecific.itemId.buf = 0;
+    variableIdentifier->variableSpecification.choice.name.choice.domainspecific.itemId.size = 0;
+
+    asn_DEF_MmsPdu.free_struct(&asn_DEF_MmsPdu, mmsPdu, 0);
+
+    return rval.encoded;
+}
+
 static ListOfVariableSeq_t**
 createListOfVariables(ReadRequest_t* readRequest, int valuesCount)
 {