open62541/src/server/ua_services_view.c

#include "ua_server_internal.h"
#include "ua_services.h"

static UA_StatusCode
fillReferenceDescription(UA_NodeStore *ns, const UA_Node *curr, UA_ReferenceNode *ref,
                         UA_UInt32 mask, UA_ReferenceDescription *descr) {
    UA_ReferenceDescription_init(descr);
    UA_StatusCode retval = UA_NodeId_copy(&curr->nodeId, &descr->nodeId.nodeId);
    if(mask & UA_BROWSERESULTMASK_REFERENCETYPEID)
        retval |= UA_NodeId_copy(&ref->referenceTypeId, &descr->referenceTypeId);
    if(mask & UA_BROWSERESULTMASK_ISFORWARD)
        descr->isForward = !ref->isInverse;
    if(mask & UA_BROWSERESULTMASK_NODECLASS)
        retval |= UA_NodeClass_copy(&curr->nodeClass, &descr->nodeClass);
    if(mask & UA_BROWSERESULTMASK_BROWSENAME)
        retval |= UA_QualifiedName_copy(&curr->browseName, &descr->browseName);
    if(mask & UA_BROWSERESULTMASK_DISPLAYNAME)
        retval |= UA_LocalizedText_copy(&curr->displayName, &descr->displayName);
    if(mask & UA_BROWSERESULTMASK_TYPEDEFINITION){
        if(curr->nodeClass == UA_NODECLASS_OBJECT || curr->nodeClass == UA_NODECLASS_VARIABLE) {
            for(size_t i = 0; i < curr->referencesSize; i++) {
                UA_ReferenceNode *refnode = &curr->references[i];
                if(refnode->referenceTypeId.identifier.numeric == UA_NS0ID_HASTYPEDEFINITION) {
                    retval |= UA_ExpandedNodeId_copy(&refnode->targetId, &descr->typeDefinition);
                    break;
                }
            }
        }
    }
    return retval;
}

#ifdef UA_ENABLE_EXTERNAL_NAMESPACES
static const UA_Node *
returnRelevantNodeExternal(UA_ExternalNodeStore *ens, const UA_BrowseDescription *descr,
                           const UA_ReferenceNode *reference) {
    /* prepare a read request in the external nodestore */
    UA_ReadValueId *readValueIds = UA_Array_new(6,&UA_TYPES[UA_TYPES_READVALUEID]);
    UA_UInt32 *indices = UA_Array_new(6,&UA_TYPES[UA_TYPES_UINT32]);
    UA_UInt32 indicesSize = 6;
    UA_DataValue *readNodesResults = UA_Array_new(6,&UA_TYPES[UA_TYPES_DATAVALUE]);
    UA_DiagnosticInfo *diagnosticInfos = UA_Array_new(6,&UA_TYPES[UA_TYPES_DIAGNOSTICINFO]);
    for(UA_UInt32 i = 0; i < 6; i++) {
        readValueIds[i].nodeId = reference->targetId.nodeId;
        indices[i] = i;
    }
    readValueIds[0].attributeId = UA_ATTRIBUTEID_NODECLASS;
    readValueIds[1].attributeId = UA_ATTRIBUTEID_BROWSENAME;
    readValueIds[2].attributeId = UA_ATTRIBUTEID_DISPLAYNAME;
    readValueIds[3].attributeId = UA_ATTRIBUTEID_DESCRIPTION;
    readValueIds[4].attributeId = UA_ATTRIBUTEID_WRITEMASK;
    readValueIds[5].attributeId = UA_ATTRIBUTEID_USERWRITEMASK;

    ens->readNodes(ens->ensHandle, NULL, readValueIds, indices,
                   indicesSize, readNodesResults, false, diagnosticInfos);

    /* create and fill a dummy nodeStructure */
    UA_Node *node = (UA_Node*) UA_NodeStore_newObjectNode();
    UA_NodeId_copy(&(reference->targetId.nodeId), &(node->nodeId));
    if(readNodesResults[0].status == UA_STATUSCODE_GOOD)
        UA_NodeClass_copy((UA_NodeClass*)readNodesResults[0].value.data, &(node->nodeClass));
    if(readNodesResults[1].status == UA_STATUSCODE_GOOD)
        UA_QualifiedName_copy((UA_QualifiedName*)readNodesResults[1].value.data, &(node->browseName));
    if(readNodesResults[2].status == UA_STATUSCODE_GOOD)
        UA_LocalizedText_copy((UA_LocalizedText*)readNodesResults[2].value.data, &(node->displayName));
    if(readNodesResults[3].status == UA_STATUSCODE_GOOD)
        UA_LocalizedText_copy((UA_LocalizedText*)readNodesResults[3].value.data, &(node->description));
    if(readNodesResults[4].status == UA_STATUSCODE_GOOD)
        UA_UInt32_copy((UA_UInt32*)readNodesResults[4].value.data, &(node->writeMask));
    if(readNodesResults[5].status == UA_STATUSCODE_GOOD)
        UA_UInt32_copy((UA_UInt32*)readNodesResults[5].value.data, &(node->userWriteMask));
    UA_Array_delete(readValueIds,6, &UA_TYPES[UA_TYPES_READVALUEID]);
    UA_Array_delete(indices,6, &UA_TYPES[UA_TYPES_UINT32]);
    UA_Array_delete(readNodesResults,6, &UA_TYPES[UA_TYPES_DATAVALUE]);
    UA_Array_delete(diagnosticInfos,6, &UA_TYPES[UA_TYPES_DIAGNOSTICINFO]);
    if(node && descr->nodeClassMask != 0 && (node->nodeClass & descr->nodeClassMask) == 0) {
        UA_NodeStore_deleteNode(node);
        return NULL;
    }
    return node;
}
#endif

/* Tests if the node is relevant to the browse request and shall be returned. If
   so, it is retrieved from the Nodestore. If not, null is returned. */
static const UA_Node *
returnRelevantNode(UA_Server *server, const UA_BrowseDescription *descr, UA_Boolean return_all,
                   const UA_ReferenceNode *reference, const UA_NodeId *relevant, size_t relevant_count,
                   UA_Boolean *isExternal) {
    /* reference in the right direction? */
    if(reference->isInverse && descr->browseDirection == UA_BROWSEDIRECTION_FORWARD)
        return NULL;
    if(!reference->isInverse && descr->browseDirection == UA_BROWSEDIRECTION_INVERSE)
        return NULL;

    /* is the reference part of the hierarchy of references we look for? */
    if(!return_all) {
        UA_Boolean is_relevant = false;
        for(size_t i = 0; i < relevant_count; i++) {
            if(UA_NodeId_equal(&reference->referenceTypeId, &relevant[i])) {
                is_relevant = true;
                break;
            }
        }
        if(!is_relevant)
            return NULL;
    }

#ifdef UA_ENABLE_EXTERNAL_NAMESPACES
    /* return the node from an external namespace*/
    for(size_t nsIndex = 0; nsIndex < server->externalNamespacesSize; nsIndex++) {
        if(reference->targetId.nodeId.namespaceIndex != server->externalNamespaces[nsIndex].index)
            continue;
        *isExternal = true;
        return returnRelevantNodeExternal(&server->externalNamespaces[nsIndex].externalNodeStore,
                                          descr, reference);
    }
#endif

    /* return from the internal nodestore */
    const UA_Node *node = UA_NodeStore_get(server->nodestore, &reference->targetId.nodeId);
    if(node && descr->nodeClassMask != 0 && (node->nodeClass & descr->nodeClassMask) == 0)
        return NULL;
    *isExternal = false;
    return node;
}

/**
 * We find all subtypes by a single iteration over the array. We start with an array with a single
 * root nodeid at the beginning. When we find relevant references, we add the nodeids to the back of
 * the array and increase the size. Since the hierarchy is not cyclic, we can safely progress in the
 * array to process the newly found referencetype nodeids (emulated recursion).
 */
static UA_StatusCode
findSubTypes(UA_NodeStore *ns, const UA_NodeId *root, UA_NodeId **reftypes, size_t *reftypes_count) {
    const UA_Node *node = UA_NodeStore_get(ns, root);
    if(!node)
        return UA_STATUSCODE_BADNOMATCH;
    if(node->nodeClass != UA_NODECLASS_REFERENCETYPE)
        return UA_STATUSCODE_BADREFERENCETYPEIDINVALID;

    size_t results_size = 20; // probably too big, but saves mallocs
    UA_NodeId *results = UA_malloc(sizeof(UA_NodeId) * results_size);
    if(!results)
        return UA_STATUSCODE_BADOUTOFMEMORY;

    UA_StatusCode retval = UA_NodeId_copy(root, &results[0]);
    if(retval != UA_STATUSCODE_GOOD) {
        UA_free(results);
        return retval;
    }
        
    size_t idx = 0; // where are we currently in the array?
    size_t last = 0; // where is the last element in the array?
    do {
        node = UA_NodeStore_get(ns, &results[idx]);
        if(!node || node->nodeClass != UA_NODECLASS_REFERENCETYPE)
            continue;
        for(size_t i = 0; i < node->referencesSize; i++) {
            if(node->references[i].referenceTypeId.identifier.numeric != UA_NS0ID_HASSUBTYPE ||
               node->references[i].isInverse == true)
                continue;

            if(++last >= results_size) { // is the array big enough?
                UA_NodeId *new_results = UA_realloc(results, sizeof(UA_NodeId) * results_size * 2);
                if(!new_results) {
                    retval = UA_STATUSCODE_BADOUTOFMEMORY;
                    break;
                }
                results = new_results;
                results_size *= 2;
            }

            retval = UA_NodeId_copy(&node->references[i].targetId.nodeId, &results[last]);
            if(retval != UA_STATUSCODE_GOOD) {
                last--; // for array_delete
                break;
            }
        }
    } while(++idx <= last && retval == UA_STATUSCODE_GOOD);

    if(retval != UA_STATUSCODE_GOOD) {
        UA_Array_delete(results, last, &UA_TYPES[UA_TYPES_NODEID]);
        return retval;
    }

    *reftypes = results;
    *reftypes_count = last + 1;
    return UA_STATUSCODE_GOOD;
}

static void removeCp(struct ContinuationPointEntry *cp, UA_Session* session) {
    LIST_REMOVE(cp, pointers);
    UA_ByteString_deleteMembers(&cp->identifier);
    UA_BrowseDescription_deleteMembers(&cp->browseDescription);
    UA_free(cp);
    session->availableContinuationPoints++;
}

/**
 * Results for a single browsedescription. This is the inner loop for both Browse and BrowseNext
 * @param session Session to save continuationpoints
 * @param ns The nodstore where the to-be-browsed node can be found
 * @param cp If cp is not null, we continue from here
 *           If cp is null, we can add a new continuation point if possible and necessary.
 * @param descr If no cp is set, we take the browsedescription from there
 * @param maxrefs The maximum number of references the client has requested
 * @param result The entry in the request
 */
void
Service_Browse_single(UA_Server *server, UA_Session *session,
                      struct ContinuationPointEntry *cp, const UA_BrowseDescription *descr,
                      UA_UInt32 maxrefs, UA_BrowseResult *result) { 
    size_t referencesCount = 0;
    size_t referencesIndex = 0;
    /* set the browsedescription if a cp is given */
    UA_UInt32 continuationIndex = 0;
    if(cp) {
        descr = &cp->browseDescription;
        maxrefs = cp->maxReferences;
        continuationIndex = cp->continuationIndex;
    }

    /* is the browsedirection valid? */
    if(descr->browseDirection != UA_BROWSEDIRECTION_BOTH &&
       descr->browseDirection != UA_BROWSEDIRECTION_FORWARD &&
       descr->browseDirection != UA_BROWSEDIRECTION_INVERSE) {
        result->statusCode = UA_STATUSCODE_BADBROWSEDIRECTIONINVALID;
        return;
    }
    
    /* get the references that match the browsedescription */
    size_t relevant_refs_size = 0;
    UA_NodeId *relevant_refs = NULL;
    UA_Boolean all_refs = UA_NodeId_isNull(&descr->referenceTypeId);
    if(!all_refs) {
        if(descr->includeSubtypes) {
            result->statusCode = findSubTypes(server->nodestore, &descr->referenceTypeId,
                                              &relevant_refs, &relevant_refs_size);
            if(result->statusCode != UA_STATUSCODE_GOOD)
                return;
        } else {
            const UA_Node *rootRef = UA_NodeStore_get(server->nodestore, &descr->referenceTypeId);
            if(!rootRef || rootRef->nodeClass != UA_NODECLASS_REFERENCETYPE) {
                result->statusCode = UA_STATUSCODE_BADREFERENCETYPEIDINVALID;
                return;
            }
            relevant_refs = (UA_NodeId*)(uintptr_t)&descr->referenceTypeId;
            relevant_refs_size = 1;
        }
    }

    /* get the node */
    const UA_Node *node = UA_NodeStore_get(server->nodestore, &descr->nodeId);
    if(!node) {
        result->statusCode = UA_STATUSCODE_BADNODEIDUNKNOWN;
        if(!all_refs && descr->includeSubtypes)
            UA_Array_delete(relevant_refs, relevant_refs_size, &UA_TYPES[UA_TYPES_NODEID]);
        return;
    }

    /* if the node has no references, just return */
    if(node->referencesSize == 0) {
        result->referencesSize = 0;
        if(!all_refs && descr->includeSubtypes)
            UA_Array_delete(relevant_refs, relevant_refs_size, &UA_TYPES[UA_TYPES_NODEID]);
        return;
    }

    /* how many references can we return at most? */
    size_t real_maxrefs = maxrefs;
    if(real_maxrefs == 0)
        real_maxrefs = node->referencesSize;
    if(node->referencesSize == 0)
        real_maxrefs = 0;
    else if(real_maxrefs > node->referencesSize)
        real_maxrefs = node->referencesSize;
    result->references = UA_Array_new(real_maxrefs, &UA_TYPES[UA_TYPES_REFERENCEDESCRIPTION]);
    if(!result->references) {
        result->statusCode = UA_STATUSCODE_BADOUTOFMEMORY;
        goto cleanup;
    }

    /* loop over the node's references */
    size_t skipped = 0;
    UA_Boolean isExternal = false;
    UA_StatusCode retval = UA_STATUSCODE_GOOD;
    for(; referencesIndex < node->referencesSize && referencesCount < real_maxrefs; referencesIndex++) {
        isExternal = false;
        const UA_Node *current =
            returnRelevantNode(server, descr, all_refs, &node->references[referencesIndex],
                               relevant_refs, relevant_refs_size, &isExternal);
        if(!current)
            continue;

        if(skipped < continuationIndex) {
            skipped++;
        } else {
            retval |= fillReferenceDescription(server->nodestore, current,
                                               &node->references[referencesIndex],
                                               descr->resultMask,
                                               &result->references[referencesCount]);
            referencesCount++;
        }
    }

    result->referencesSize = referencesCount;
    if(referencesCount == 0) {
        UA_free(result->references);
        result->references = NULL;
    }

    if(retval != UA_STATUSCODE_GOOD) {
        UA_Array_delete(result->references, result->referencesSize,
                        &UA_TYPES[UA_TYPES_REFERENCEDESCRIPTION]);
        result->references = NULL;
        result->referencesSize = 0;
        result->statusCode = retval;
    }

    cleanup:
    if(!all_refs && descr->includeSubtypes)
        UA_Array_delete(relevant_refs, relevant_refs_size, &UA_TYPES[UA_TYPES_NODEID]);
    if(result->statusCode != UA_STATUSCODE_GOOD)
        return;

    /* create, update, delete continuation points */
    if(cp) {
        if(referencesIndex == node->referencesSize) {
            /* all done, remove a finished continuationPoint */
            removeCp(cp, session);
        } else {
            /* update the cp and return the cp identifier */
            cp->continuationIndex += (UA_UInt32)referencesCount;
            UA_ByteString_copy(&cp->identifier, &result->continuationPoint);
        }
    } else if(maxrefs != 0 && referencesCount >= maxrefs) {
        /* create a cp */
        if(session->availableContinuationPoints <= 0 ||
           !(cp = UA_malloc(sizeof(struct ContinuationPointEntry)))) {
            result->statusCode = UA_STATUSCODE_BADNOCONTINUATIONPOINTS;
            return;
        }
        UA_BrowseDescription_copy(descr, &cp->browseDescription);
        cp->maxReferences = maxrefs;
        cp->continuationIndex = (UA_UInt32)referencesCount;
        UA_Guid *ident = UA_Guid_new();
        *ident = UA_Guid_random();
        cp->identifier.data = (UA_Byte*)ident;
        cp->identifier.length = sizeof(UA_Guid);
        UA_ByteString_copy(&cp->identifier, &result->continuationPoint);

        /* store the cp */
        LIST_INSERT_HEAD(&session->continuationPoints, cp, pointers);
        session->availableContinuationPoints--;
    }
}

void Service_Browse(UA_Server *server, UA_Session *session, const UA_BrowseRequest *request,
                    UA_BrowseResponse *response) {
    UA_LOG_DEBUG_SESSION(server->config.logger, session, "Processing BrowseRequest");
    if(!UA_NodeId_isNull(&request->view.viewId)) {
        response->responseHeader.serviceResult = UA_STATUSCODE_BADVIEWIDUNKNOWN;
        return;
    }

    if(request->nodesToBrowseSize <= 0) {
        response->responseHeader.serviceResult = UA_STATUSCODE_BADNOTHINGTODO;
        return;
    }

    size_t size = request->nodesToBrowseSize;
    response->results = UA_Array_new(size, &UA_TYPES[UA_TYPES_BROWSERESULT]);
    if(!response->results) {
        response->responseHeader.serviceResult = UA_STATUSCODE_BADOUTOFMEMORY;
        return;
    }
    response->resultsSize = size;

#ifdef UA_ENABLE_EXTERNAL_NAMESPACES
#ifdef NO_ALLOCA
    UA_Boolean isExternal[size];
    UA_UInt32 indices[size];
#else
    UA_Boolean *isExternal = UA_alloca(sizeof(UA_Boolean) * size);
    UA_UInt32 *indices = UA_alloca(sizeof(UA_UInt32) * size);
#endif /*NO_ALLOCA */
    memset(isExternal, false, sizeof(UA_Boolean) * size);
    for(size_t j = 0; j < server->externalNamespacesSize; j++) {
        size_t indexSize = 0;
        for(size_t i = 0; i < size; i++) {
            if(request->nodesToBrowse[i].nodeId.namespaceIndex != server->externalNamespaces[j].index)
                continue;
            isExternal[i] = true;
            indices[indexSize] = (UA_UInt32)i;
            indexSize++;
        }
        if(indexSize == 0)
            continue;
        UA_ExternalNodeStore *ens = &server->externalNamespaces[j].externalNodeStore;
        ens->browseNodes(ens->ensHandle, &request->requestHeader, request->nodesToBrowse, indices,
                         (UA_UInt32)indexSize, request->requestedMaxReferencesPerNode,
                         response->results, response->diagnosticInfos);
    }
#endif

    for(size_t i = 0; i < size; i++) {
#ifdef UA_ENABLE_EXTERNAL_NAMESPACES
        if(!isExternal[i])
#endif
            Service_Browse_single(server, session, NULL, &request->nodesToBrowse[i],
                                  request->requestedMaxReferencesPerNode, &response->results[i]);
    }
}

UA_BrowseResult
UA_Server_browse(UA_Server *server, UA_UInt32 maxrefs, const UA_BrowseDescription *descr) {
    UA_BrowseResult result;
    UA_BrowseResult_init(&result);
    UA_RCU_LOCK();
    Service_Browse_single(server, &adminSession, NULL, descr, maxrefs, &result);
    UA_RCU_UNLOCK();
    return result;
}

static void
UA_Server_browseNext_single(UA_Server *server, UA_Session *session, UA_Boolean releaseContinuationPoint,
                            const UA_ByteString *continuationPoint, UA_BrowseResult *result) {
    result->statusCode = UA_STATUSCODE_BADCONTINUATIONPOINTINVALID;
    struct ContinuationPointEntry *cp, *temp;
    LIST_FOREACH_SAFE(cp, &session->continuationPoints, pointers, temp) {
        if(UA_ByteString_equal(&cp->identifier, continuationPoint)) {
            result->statusCode = UA_STATUSCODE_GOOD;
            if(!releaseContinuationPoint)
                Service_Browse_single(server, session, cp, NULL, 0, result);
            else
                removeCp(cp, session);
            break;
        }
    }
}

void Service_BrowseNext(UA_Server *server, UA_Session *session, const UA_BrowseNextRequest *request,
                        UA_BrowseNextResponse *response) {
    UA_LOG_DEBUG_SESSION(server->config.logger, session, "Processing BrowseNextRequest");
    if(request->continuationPointsSize <= 0) {
        response->responseHeader.serviceResult = UA_STATUSCODE_BADNOTHINGTODO;
        return;
    }
    size_t size = request->continuationPointsSize;
    response->results = UA_Array_new(size, &UA_TYPES[UA_TYPES_BROWSERESULT]);
    if(!response->results) {
        response->responseHeader.serviceResult = UA_STATUSCODE_BADOUTOFMEMORY;
        return;
    }

    response->resultsSize = size;
    for(size_t i = 0; i < size; i++)
        UA_Server_browseNext_single(server, session, request->releaseContinuationPoints,
                                    &request->continuationPoints[i], &response->results[i]);
}

UA_BrowseResult
UA_Server_browseNext(UA_Server *server, UA_Boolean releaseContinuationPoint,
                     const UA_ByteString *continuationPoint) {
    UA_BrowseResult result;
    UA_BrowseResult_init(&result);
    UA_RCU_LOCK();
    UA_Server_browseNext_single(server, &adminSession, releaseContinuationPoint,
                                continuationPoint, &result);
    UA_RCU_UNLOCK();
    return result;
}

/***********************/
/* TranslateBrowsePath */
/***********************/

static UA_StatusCode
walkBrowsePath(UA_Server *server, UA_Session *session, const UA_Node *node, const UA_RelativePath *path,
               size_t pathindex, UA_BrowsePathTarget **targets, size_t *targets_size,
               size_t *target_count) {
    const UA_RelativePathElement *elem = &path->elements[pathindex];
    UA_StatusCode retval = UA_STATUSCODE_GOOD;
    UA_NodeId *reftypes = NULL;
    size_t reftypes_count = 1; // all_refs or no subtypes => 1
    UA_Boolean all_refs = false;
    if(UA_NodeId_isNull(&elem->referenceTypeId)) {
        all_refs = true;
    } else if(!elem->includeSubtypes) {
        reftypes = (UA_NodeId*)(uintptr_t)&elem->referenceTypeId; // ptr magic due to const cast
    } else {
        retval = findSubTypes(server->nodestore, &elem->referenceTypeId, &reftypes, &reftypes_count);
        if(retval != UA_STATUSCODE_GOOD)
            return retval;
    }

    for(size_t i = 0; i < node->referencesSize && retval == UA_STATUSCODE_GOOD; i++) {
        UA_Boolean match = all_refs;
        for(size_t j = 0; j < reftypes_count && !match; j++) {
            if(node->references[i].isInverse == elem->isInverse &&
               UA_NodeId_equal(&node->references[i].referenceTypeId, &reftypes[j]))
                match = true;
        }
        if(!match)
            continue;

        // get the node, todo: expandednodeid
        const UA_Node *next = UA_NodeStore_get(server->nodestore, &node->references[i].targetId.nodeId);
        if(!next)
            continue;

        // test the browsename
        if(elem->targetName.namespaceIndex != next->browseName.namespaceIndex ||
           !UA_String_equal(&elem->targetName.name, &next->browseName.name)) {
            continue;
        }

        if(pathindex + 1 < path->elementsSize) {
            // recursion if the path is longer
            retval = walkBrowsePath(server, session, next, path, pathindex + 1,
                                    targets, targets_size, target_count);
        } else {
            // add the browsetarget
            if(*target_count >= *targets_size) {
                UA_BrowsePathTarget *newtargets;
                newtargets = UA_realloc(targets, sizeof(UA_BrowsePathTarget) * (*targets_size) * 2);
                if(!newtargets) {
                    retval = UA_STATUSCODE_BADOUTOFMEMORY;
                    break;
                }
                *targets = newtargets;
                *targets_size *= 2;
            }

            UA_BrowsePathTarget *res = *targets;
            UA_ExpandedNodeId_init(&res[*target_count].targetId);
            retval = UA_NodeId_copy(&next->nodeId, &res[*target_count].targetId.nodeId);
            if(retval != UA_STATUSCODE_GOOD)
                break;
            res[*target_count].remainingPathIndex = UA_UINT32_MAX;
            *target_count += 1;
        }
    }

    if(!all_refs && elem->includeSubtypes)
        UA_Array_delete(reftypes, reftypes_count, &UA_TYPES[UA_TYPES_NODEID]);
    return retval;
}

void Service_TranslateBrowsePathsToNodeIds_single(UA_Server *server, UA_Session *session,
                                                  const UA_BrowsePath *path, UA_BrowsePathResult *result) {
    if(path->relativePath.elementsSize <= 0) {
        result->statusCode = UA_STATUSCODE_BADNOTHINGTODO;
        return;
    }
        
    //relativePath elements should not have an empty targetName
    for(size_t i=0;i<path->relativePath.elementsSize;i++){
        UA_QualifiedName *qname = &(path->relativePath.elements[i].targetName);
        if(UA_QualifiedName_isNull(qname)){
            result->statusCode = UA_STATUSCODE_BADBROWSENAMEINVALID;
            return;
        }
    }

    size_t arraySize = 10;
    result->targets = UA_malloc(sizeof(UA_BrowsePathTarget) * arraySize);
    if(!result->targets) {
        result->statusCode = UA_STATUSCODE_BADOUTOFMEMORY;
        return;
    }
    result->targetsSize = 0;
    const UA_Node *firstNode = UA_NodeStore_get(server->nodestore, &path->startingNode);
    if(!firstNode) {
        result->statusCode = UA_STATUSCODE_BADNODEIDUNKNOWN;
        UA_free(result->targets);
        result->targets = NULL;
        return;
    }

    result->statusCode = walkBrowsePath(server, session, firstNode, &path->relativePath, 0,
                                        &result->targets, &arraySize, &result->targetsSize);
    if(result->targetsSize == 0 && result->statusCode == UA_STATUSCODE_GOOD)
        result->statusCode = UA_STATUSCODE_BADNOMATCH;

    if(result->statusCode != UA_STATUSCODE_GOOD) {
        UA_Array_delete(result->targets, result->targetsSize, &UA_TYPES[UA_TYPES_BROWSEPATHTARGET]);
        result->targets = NULL;
        result->targetsSize = 0;
    }
}

void Service_TranslateBrowsePathsToNodeIds(UA_Server *server, UA_Session *session,
                                           const UA_TranslateBrowsePathsToNodeIdsRequest *request,
                                           UA_TranslateBrowsePathsToNodeIdsResponse *response) {
    UA_LOG_DEBUG_SESSION(server->config.logger, session, "Processing TranslateBrowsePathsToNodeIdsRequest");
    if(request->browsePathsSize <= 0) {
        response->responseHeader.serviceResult = UA_STATUSCODE_BADNOTHINGTODO;
        return;
    }

    size_t size = request->browsePathsSize;
    response->results = UA_Array_new(size, &UA_TYPES[UA_TYPES_BROWSEPATHRESULT]);
    if(!response->results) {
        response->responseHeader.serviceResult = UA_STATUSCODE_BADOUTOFMEMORY;
        return;
    }

#ifdef UA_ENABLE_EXTERNAL_NAMESPACES
#ifdef NO_ALLOCA
    UA_Boolean isExternal[size];
    UA_UInt32 indices[size];
#else
    UA_Boolean *isExternal = UA_alloca(sizeof(UA_Boolean) * size);
    UA_UInt32 *indices = UA_alloca(sizeof(UA_UInt32) * size);
#endif /* NO_ALLOCA */
    memset(isExternal, false, sizeof(UA_Boolean) * size);
    for(size_t j = 0; j < server->externalNamespacesSize; j++) {
        size_t indexSize = 0;
        for(size_t i = 0;i < size;i++) {
            if(request->browsePaths[i].startingNode.namespaceIndex != server->externalNamespaces[j].index)
                continue;
            isExternal[i] = true;
            indices[indexSize] = (UA_UInt32)i;
            indexSize++;
        }
        if(indexSize == 0)
            continue;
        UA_ExternalNodeStore *ens = &server->externalNamespaces[j].externalNodeStore;
        ens->translateBrowsePathsToNodeIds(ens->ensHandle, &request->requestHeader, request->browsePaths,
                                           indices, (UA_UInt32)indexSize, response->results,
                                           response->diagnosticInfos);
    }
#endif

    response->resultsSize = size;
    for(size_t i = 0; i < size; i++) {
#ifdef UA_ENABLE_EXTERNAL_NAMESPACES
        if(!isExternal[i])
#endif
            Service_TranslateBrowsePathsToNodeIds_single(server, session, &request->browsePaths[i],
                                                         &response->results[i]);
    }
}

void Service_RegisterNodes(UA_Server *server, UA_Session *session, const UA_RegisterNodesRequest *request,
                           UA_RegisterNodesResponse *response) {
    UA_LOG_DEBUG_SESSION(server->config.logger, session, "Processing RegisterNodesRequest");
    //TODO: hang the nodeids to the session if really needed
    response->responseHeader.timestamp = UA_DateTime_now();
    if(request->nodesToRegisterSize <= 0)
        response->responseHeader.serviceResult = UA_STATUSCODE_BADNOTHINGTODO;
    else {
        response->responseHeader.serviceResult =
            UA_Array_copy(request->nodesToRegister, request->nodesToRegisterSize,
                          (void**)&response->registeredNodeIds, &UA_TYPES[UA_TYPES_NODEID]);
        if(response->responseHeader.serviceResult == UA_STATUSCODE_GOOD)
            response->registeredNodeIdsSize = request->nodesToRegisterSize;
    }
}

void Service_UnregisterNodes(UA_Server *server, UA_Session *session, const UA_UnregisterNodesRequest *request,
                             UA_UnregisterNodesResponse *response) {
    UA_LOG_DEBUG_SESSION(server->config.logger, session, "Processing UnRegisterNodesRequest");
    //TODO: remove the nodeids from the session if really needed
    response->responseHeader.timestamp = UA_DateTime_now();
    if(request->nodesToUnregisterSize==0)
        response->responseHeader.serviceResult = UA_STATUSCODE_BADNOTHINGTODO;
}