- MMS client/server: added support for component alternate access for generic variable read requests

examples/mms_utility/mms_utility.c

@@ -18,6 +18,7 @@ print_help()
     printf("-i show server identity\n");
     printf("-t <domain_name> show domain directory\n");
     printf("-r <variable_name> read domain variable\n");
+    printf("-c <component_name> specify component name for variable read\n");
     printf("-a <domain_name> specify domain for read or write command\n");
     printf("-f show file list\n");
     printf("-g <filename> get file attributes\n");
@@ -105,6 +106,7 @@ int main(int argc, char** argv) {
 
 	char* domainName = NULL;
 	char* variableName = NULL;
+	char* componentName = NULL;
 	char* filename = NULL;
 	char* journalName = NULL;
 
@@ -122,7 +124,7 @@ int main(int argc, char** argv) {
 
 	int c;
 
-	while ((c = getopt(argc, argv, "mifdh:p:l:t:a:r:g:j:x:v:")) != -1)
+	while ((c = getopt(argc, argv, "mifdh:p:l:t:a:r:g:j:x:v:c:")) != -1)
 		switch (c) {
 		case 'm':
 		    printRawMmsMessages = 1;
@@ -155,6 +157,9 @@ int main(int argc, char** argv) {
 		    readVariable = 1;
 		    variableName = StringUtils_copyString(optarg);
 		    break;
+		case 'c':
+			componentName = StringUtils_copyString(optarg);
+			break;
 		case 'v':
 		    readVariableList = 1;
 		    variableName = StringUtils_copyString(optarg);
@@ -323,7 +328,13 @@ int main(int argc, char** argv) {
 
 	if (readVariable) {
 	    if (readWriteHasDomain) {
-	        MmsValue* result = MmsConnection_readVariable(con, &error, domainName, variableName);
+
+	    	MmsValue* result;
+
+	    	if (componentName == NULL)
+	    		result = MmsConnection_readVariable(con, &error, domainName, variableName);
+	    	else
+	    		result = MmsConnection_readVariableComponent(con, &error, domainName, variableName, componentName);
 
 	        if (error != MMS_ERROR_NONE) {
 	            printf("Reading variable failed: (ERROR %i)\n", error);

src/mms/inc/mms_client_connection.h

@@ -373,6 +373,23 @@ MmsConnection_getVariableListNamesAssociationSpecific(MmsConnection self, MmsErr
 MmsValue*
 MmsConnection_readVariable(MmsConnection self, MmsError* mmsError, const char* domainId, const char* itemId);
 
+/**
+ * \brief Read a component of a single variable 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 or NULL to read a VMD specific named variable
+ * \param itemId name of the variable to be read
+ * \param componentId the component name
+ *
+ * \return Returns a MmsValue object or NULL if the request failed. The MmsValue object can
+ * either be a simple value or a complex value or array. It is also possible that the return value is NULL
+ * even if mmsError = MMS_ERROR_NON. This is the case when the servers returns an empty result list.
+ */
+MmsValue*
+MmsConnection_readVariableComponent(MmsConnection self, MmsError* mmsError,
+        const char* domainId, const char* itemId, const char* componentId);
+
 /**
  * \brief Read one or more elements of a single array variable from the server.
  *

src/mms/inc_private/mms_client_internal.h

@@ -160,6 +160,9 @@ mmsClient_parseReadResponse(ByteBuffer* message, uint32_t* invokeId, bool create
 int
 mmsClient_createReadRequest(uint32_t invokeId, const char* domainId, const char* itemId, ByteBuffer* writeBuffer);
 
+int
+mmsClient_createReadRequestComponent(uint32_t invokeId, const char* domainId, const char* itemId, const char* component, ByteBuffer* writeBuffer);
+
 int
 mmsClient_createReadRequestAlternateAccessIndex(uint32_t invokeId, const char* domainId, const char* itemId,
 		uint32_t index, uint32_t elementCount, ByteBuffer* writeBuffer);

src/mms/inc_private/mms_server_internal.h

@@ -357,9 +357,13 @@ mmsServer_handleObtainFileRequest(
         uint32_t invokeId,
         ByteBuffer* response);
 
-int
+
+bool
 mmsServer_isIndexAccess(AlternateAccess_t* alternateAccess);
 
+bool
+mmsServer_isComponentAccess(AlternateAccess_t* alternateAccess);
+
 int
 mmsServer_getLowIndex(AlternateAccess_t* alternateAccess);
 

src/mms/iso_mms/client/mms_client_connection.c

@@ -1589,6 +1589,34 @@ MmsConnection_readVariable(MmsConnection self, MmsError* mmsError,
     return value;
 }
 
+MmsValue*
+MmsConnection_readVariableComponent(MmsConnection self, MmsError* mmsError,
+        const char* domainId, const char* itemId, 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_createReadRequestComponent(invokeId, domainId, itemId, 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_readArrayElements(MmsConnection self, MmsError* mmsError,
         const char* domainId, const char* itemId,

src/mms/iso_mms/client/mms_client_read.c

@@ -528,7 +528,7 @@ mmsClient_createReadRequest(uint32_t invokeId, const char* domainId, const char*
 }
 
 static AlternateAccess_t*
-createAlternateAccess(uint32_t index, uint32_t elementCount)
+createAlternateAccessComponent(const char* componentName)
 {
     AlternateAccess_t* alternateAccess = (AlternateAccess_t*) GLOBAL_CALLOC(1, sizeof(AlternateAccess_t));
     alternateAccess->list.count = 1;
@@ -538,37 +538,114 @@ createAlternateAccess(uint32_t index, uint32_t elementCount)
 
     alternateAccess->list.array[0]->choice.unnamed = (AlternateAccessSelection_t*) GLOBAL_CALLOC(1, sizeof(AlternateAccessSelection_t));
 
+    const 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*) StringUtils_copySubString((char*) componentName, (char*) separator);
+        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;
 
-    if (elementCount > 0) {
         alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.present =
-                AlternateAccessSelection__selectAccess_PR_indexRange;
+                AlternateAccessSelection__selectAccess_PR_component;
 
-        INTEGER_t* asnIndex =
-                &(alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.indexRange.lowIndex);
+		alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.component.buf =
+			(uint8_t*) StringUtils_copyString(componentName);
+        alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.component.size = size;
+    }
 
-        asn_long2INTEGER(asnIndex, index);
+    return alternateAccess;
+}
 
-        asnIndex =
-                &(alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.indexRange.numberOfElements);
+static void
+deleteAlternateAccessComponent(AlternateAccess_t* alternateAccess)
+{
+    GLOBAL_FREEMEM(alternateAccess->list.array[0]->choice.unnamed);
+    GLOBAL_FREEMEM(alternateAccess->list.array[0]);
+    GLOBAL_FREEMEM(alternateAccess->list.array);
+    GLOBAL_FREEMEM(alternateAccess);
+}
 
-        asn_long2INTEGER(asnIndex, elementCount);
+static ListOfVariableSeq_t*
+createNewVariableSpecification(const char* domainId, const char* itemId, const char* componentName, bool associationSpecific)
+{
+    ListOfVariableSeq_t* varSpec = (ListOfVariableSeq_t*) GLOBAL_CALLOC(1, sizeof(ListOfVariableSeq_t));
+
+    varSpec->variableSpecification.present = VariableSpecification_PR_name;
+
+    if (domainId) {
+        varSpec->variableSpecification.choice.name.present = ObjectName_PR_domainspecific;
+        varSpec->variableSpecification.choice.name.choice.domainspecific.domainId.buf = (uint8_t*) domainId;
+        varSpec->variableSpecification.choice.name.choice.domainspecific.domainId.size = strlen(domainId);
+        varSpec->variableSpecification.choice.name.choice.domainspecific.itemId.buf = (uint8_t*) itemId;
+        varSpec->variableSpecification.choice.name.choice.domainspecific.itemId.size = strlen(itemId);
+    }
+    else if (associationSpecific) {
+        varSpec->variableSpecification.choice.name.present = ObjectName_PR_aaspecific;
+        varSpec->variableSpecification.choice.name.choice.aaspecific.buf = (uint8_t*) itemId;
+        varSpec->variableSpecification.choice.name.choice.aaspecific.size = strlen(itemId);
     }
     else {
-        alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.present =
-                AlternateAccessSelection__selectAccess_PR_index;
+        varSpec->variableSpecification.choice.name.present = ObjectName_PR_vmdspecific;
+        varSpec->variableSpecification.choice.name.choice.vmdspecific.buf = (uint8_t*) itemId;
+        varSpec->variableSpecification.choice.name.choice.vmdspecific.size = strlen(itemId);
+    }
 
-        INTEGER_t* asnIndex =
-                &(alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.index);
+    if (componentName)
+        varSpec->alternateAccess = createAlternateAccessComponent(componentName);
 
-        asn_long2INTEGER(asnIndex, index);
+    return varSpec;
 }
 
-    return alternateAccess;
+/**
+ * Request a single value with optional component
+ */
+int
+mmsClient_createReadRequestComponent(uint32_t invokeId, const char* domainId, const char* itemId, 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.count = 1;
+    readRequest->variableAccessSpecification.choice.listOfVariable.list.size = 1;
+    readRequest->variableAccessSpecification.choice.listOfVariable.list.array =
+            (ListOfVariableSeq_t**) GLOBAL_CALLOC(1, sizeof(ListOfVariableSeq_t*));
+    readRequest->variableAccessSpecification.choice.listOfVariable.list.array[0] = createNewVariableSpecification(domainId, itemId, component, false);
+
+    asn_enc_rval_t rval;
+
+    rval = der_encode(&asn_DEF_MmsPdu, mmsPdu,
+            (asn_app_consume_bytes_f*) mmsClient_write_out, (void*) writeBuffer);
+
+    /* clean up data structures */
+    deleteAlternateAccessComponent(readRequest->variableAccessSpecification.choice.listOfVariable.list.array[0]->alternateAccess);
+
+    GLOBAL_FREEMEM(readRequest->variableAccessSpecification.choice.listOfVariable.list.array);
+    readRequest->variableAccessSpecification.choice.listOfVariable.list.array = NULL;
+    readRequest->variableAccessSpecification.choice.listOfVariable.list.count = 0;
+    asn_DEF_MmsPdu.free_struct(&asn_DEF_MmsPdu, mmsPdu, 0);
+
+    return rval.encoded;
 }
 
 static AlternateAccess_t*
-createAlternateAccessComponent(const char* componentName)
+createAlternateAccess(uint32_t index, uint32_t elementCount)
 {
     AlternateAccess_t* alternateAccess = (AlternateAccess_t*) GLOBAL_CALLOC(1, sizeof(AlternateAccess_t));
     alternateAccess->list.count = 1;
@@ -578,32 +655,30 @@ createAlternateAccessComponent(const char* componentName)
 
     alternateAccess->list.array[0]->choice.unnamed = (AlternateAccessSelection_t*) GLOBAL_CALLOC(1, sizeof(AlternateAccessSelection_t));
 
-    const char* separator = strchr(componentName, '$');
+    alternateAccess->list.array[0]->choice.unnamed->present = AlternateAccessSelection_PR_selectAccess;
 
-    if (separator) {
-        int size = separator - componentName;
+    if (elementCount > 0) {
+        alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.present =
+                AlternateAccessSelection__selectAccess_PR_indexRange;
 
-        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;
+        INTEGER_t* asnIndex =
+                &(alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.indexRange.lowIndex);
 
-        alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.accessSelection.choice.component.buf = 
-			(uint8_t*) StringUtils_copySubString((char*) componentName, (char*) separator);
-        alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.accessSelection.choice.component.size = size;
+        asn_long2INTEGER(asnIndex, index);
 
-        alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.alternateAccess = createAlternateAccessComponent(separator + 1);
+        asnIndex =
+                &(alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.indexRange.numberOfElements);
+
+        asn_long2INTEGER(asnIndex, elementCount);
     }
     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;
+                AlternateAccessSelection__selectAccess_PR_index;
 
-		alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.component.buf = 
-			(uint8_t*) StringUtils_copyString(componentName);
-        alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.component.size = size;
+        INTEGER_t* asnIndex =
+                &(alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.index);
+
+        asn_long2INTEGER(asnIndex, index);
     }
 
     return alternateAccess;

src/mms/iso_mms/server/mms_read_service.c

@@ -155,6 +155,51 @@ isAccessToArrayComponent(AlternateAccess_t* alternateAccess)
         return false;
 }
 
+static MmsValue*
+getComponent(AlternateAccess_t* alternateAccess, MmsVariableSpecification* namedVariable, MmsValue* variableValue)
+{
+    MmsValue* retValue = NULL;
+
+    if (mmsServer_isComponentAccess(alternateAccess)) {
+        Identifier_t component =
+                alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.choice.component;
+
+        if (component.size > 129)
+            goto exit_function;
+
+        if (namedVariable->type == MMS_STRUCTURE) {
+
+            int i;
+
+            for (i = 0; i < namedVariable->typeSpec.structure.elementCount;
+                    i++) {
+
+                if (strlen(namedVariable->typeSpec.structure.elements[i]->name)
+                        == component.size) {
+                    if (strncmp(
+                            namedVariable->typeSpec.structure.elements[i]->name,
+                            (char*) component.buf, component.size) == 0) {
+                        MmsValue* value = MmsValue_getElement(variableValue, i);
+
+                        if (alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.alternateAccess
+                                != NULL) {
+                            retValue =
+                                    getComponent(
+                                            alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.alternateAccess,
+                                            namedVariable->typeSpec.structure.elements[i],
+                                            value);
+                        }
+                        else
+                            retValue = value;
+                    }
+                }
+            }
+        }
+    }
+
+    exit_function: return retValue;
+}
+
 static MmsValue*
 getComponentOfArrayElement(AlternateAccess_t* alternateAccess, MmsVariableSpecification* namedVariable,
         MmsValue* structuredValue)
@@ -180,14 +225,20 @@ getComponentOfArrayElement(AlternateAccess_t* alternateAccess, MmsVariableSpecif
 
         int i;
         for (i = 0; i < structSpec->typeSpec.structure.elementCount; i++) {
-            if (strncmp (structSpec->typeSpec.structure.elements[i]->name, (char*) component.buf,
-                    component.size) == 0)
-            {
+
+            if (strlen(structSpec->typeSpec.structure.elements[i]->name)
+                    == component.size) {
+                if (strncmp(structSpec->typeSpec.structure.elements[i]->name,
+                        (char*) component.buf, component.size) == 0) {
                     MmsValue* value = MmsValue_getElement(structuredValue, i);
 
-                if (isAccessToArrayComponent(alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.alternateAccess)) {
-                    retValue = getComponentOfArrayElement(alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.alternateAccess,
-                            structSpec->typeSpec.structure.elements[i], value);
+                    if (isAccessToArrayComponent(
+                            alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.alternateAccess)) {
+                        retValue =
+                                getComponentOfArrayElement(
+                                        alternateAccess->list.array[0]->choice.unnamed->choice.selectAlternateAccess.alternateAccess,
+                                        structSpec->typeSpec.structure.elements[i],
+                                        value);
                     }
                     else
                         retValue = value;
@@ -196,6 +247,7 @@ getComponentOfArrayElement(AlternateAccess_t* alternateAccess, MmsVariableSpecif
                 }
             }
         }
+    }
 
 exit_function:
     return retValue;
@@ -288,6 +340,17 @@ addNamedVariableToResultList(MmsVariableSpecification* namedVariable, MmsDomain*
 
 		    MmsValue* value = mmsServer_getValue(connection->server, domain, nameIdStr, connection);
 
+		    if (alternateAccess != NULL) {
+		    	value = getComponent(alternateAccess, namedVariable, value);
+
+				if (value != NULL) {
+					appendValueToResultList(value, values);
+				}
+				else {
+					appendErrorToResultList(values, DATA_ACCESS_ERROR_OBJECT_NONE_EXISTENT);
+				}
+		    }
+		    else {
 				if (value != NULL) {
 					appendValueToResultList(value, values);
 				}
@@ -296,6 +359,7 @@ addNamedVariableToResultList(MmsVariableSpecification* namedVariable, MmsDomain*
 						values, connection, domain, nameIdStr);
 				}
 		    }
+		}
 		else if (namedVariable->type == MMS_ARRAY) {
 
 			if (alternateAccess != NULL) {

src/mms/iso_mms/server/mms_server_common.c

@@ -208,7 +208,7 @@ mmsMsg_createServiceErrorPdu(uint32_t invokeId, ByteBuffer* response, MmsError e
     mmsServer_createServiceErrorPduWithServiceSpecificInfo(invokeId, response, errorType, NULL, 0);
 }
 
-int
+bool
 mmsServer_isIndexAccess(AlternateAccess_t* alternateAccess)
 {
 	if (alternateAccess->list.array[0]->present == AlternateAccess__Member_PR_unnamed) {
@@ -217,13 +217,25 @@ mmsServer_isIndexAccess(AlternateAccess_t* alternateAccess)
 			(alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.present
 				== AlternateAccessSelection__selectAccess_PR_indexRange))
 		{
-			return 1;
+			return true;
 		}
-		else
-			return 0;
 	}
-	else
-		return 0;
+
+	return false;
+}
+
+bool
+mmsServer_isComponentAccess(AlternateAccess_t* alternateAccess)
+{
+    if (alternateAccess->list.array[0]->present
+            == AlternateAccess__Member_PR_unnamed) {
+        if (alternateAccess->list.array[0]->choice.unnamed->choice.selectAccess.present
+                == AlternateAccessSelection__selectAccess_PR_component) {
+            return true;
+        }
+    }
+
+    return false;
 }
 
 int