static void
AttributeReadCallback(UA_Client *client, void *userdata,
                      UA_UInt32 requestId, UA_ReadResponse *rr) {
    UA_AttributeReadContext *ctx = (UA_AttributeReadContext*)userdata;
    UA_LOG_DEBUG(&UA_Client_getConfig(client)->logger, UA_LOGCATEGORY_CLIENT,
                "Async read response for request %" PRIu32, requestId);

    /* Check the ServiceResult */
    UA_StatusCode res = rr->responseHeader.serviceResult;
    if(res != UA_STATUSCODE_GOOD)
        goto finish;

    /* Check result array size */
    if(rr->resultsSize != 1) {
        res = UA_STATUSCODE_BADINTERNALERROR;
        goto finish;
    }

    /* A Value attribute */
    UA_DataValue *dv = &rr->results[0];
    if(ctx->resultType == &UA_TYPES[UA_TYPES_DATAVALUE]) {
        ctx->userCallback(client, ctx->userContext, requestId,
                          UA_STATUSCODE_GOOD, dv);
        goto finish;
    }

    /* An ArrayDimensions attribute. Has to be an array of UInt32. */
    if(ctx->resultType == &UA_TYPES[UA_TYPES_VARIANT]) {
        if(dv->hasValue &&
           UA_Variant_hasArrayType(&dv->value, &UA_TYPES[UA_TYPES_UINT32])) {
            ctx->userCallback(client, ctx->userContext, requestId,
                              UA_STATUSCODE_GOOD, &dv->value);
        } else {
            res = UA_STATUSCODE_BADINTERNALERROR;
        }
        goto finish;
    }

    /* Check we have a scalar value of the right datatype */
    if(!dv->hasValue ||
       !UA_Variant_hasScalarType(&dv->value, ctx->resultType)) {
        res = UA_STATUSCODE_BADINTERNALERROR;
        goto finish;
    }

    /* Callback into userland */
    ctx->userCallback(client, ctx->userContext, requestId,
                      UA_STATUSCODE_GOOD, dv->value.data);

 finish://jump to label ‘finish’ [-fpermissive]
    if(res != UA_STATUSCODE_GOOD)
        ctx->userCallback(client, ctx->userContext, requestId, res, NULL);
    UA_free(ctx);
}