pubsubengine.java

基于Jabber协议的即时消息服务器

                        fullPresences = new ConcurrentHashMap<String, String>();
                        barePresences.put(subscriber.toBareJID(), fullPresences);
                    }
                }
            }
            Presence.Show show = presence.getShow();
            fullPresences.put(subscriber.toString(), show == null ? "online" : show.name());
        }
        else if (presence.getType() == Presence.Type.unavailable) {
            JID subscriber = presence.getFrom();
            Map<String, String> fullPresences = barePresences.get(subscriber.toBareJID());
            if (fullPresences != null) {
                fullPresences.remove(subscriber.toString());
                if (fullPresences.isEmpty()) {
                    barePresences.remove(subscriber.toBareJID());
                }
            }
        }
    }

    /**
     * Handles Message packets sent to the pubsub service. Messages may be of type error
     * when an event notification was sent to a susbcriber whose address is no longer available.<p>
     *
     * Answers to authorization requests sent to node owners to approve pending subscriptions
     * will also be processed by this method.
     *
     * @param message the Message packet sent to the pubsub service.
     */
    public void process(Message message) {
        if (message.getType() == Message.Type.error) {
            // Process Messages of type error to identify possible subscribers that no longer exist
            if (message.getError().getType() == PacketError.Type.cancel) {
                // TODO Assuming that owner is the bare JID (as defined in the JEP). This can be replaced with an explicit owner specified in the packet
                JID owner = new JID(message.getFrom().toBareJID());
                // Terminate the subscription of the entity to all nodes hosted at the service
               cancelAllSubscriptions(owner);
            }
            else if (message.getError().getType() == PacketError.Type.auth) {
                // TODO Queue the message to be sent again later (will retry a few times and
                // will be discarded when the retry limit is reached)
            }
        }
        else if (message.getType() == Message.Type.normal) {
            // Check that this is an answer to an authorization request
            DataForm authForm = (DataForm) message.getExtension("x", "jabber:x:data");
            if (authForm != null && authForm.getType() == DataForm.Type.submit) {
                String formType = authForm.getField("FORM_TYPE").getValues().get(0);
                // Check that completed data form belongs to an authorization request
                if ("http://jabber.org/protocol/pubsub#subscribe_authorization".equals(formType)) {
                    // Process the answer to the authorization request
                    processAuthorizationAnswer(authForm, message);
                }
            }
        }
    }

    private void publishItemsToNode(IQ iq, Element publishElement) {
        String nodeID = publishElement.attributeValue("node");
        Node node;
        if (nodeID == null) {
            // No node was specified. Return bad_request error
            Element pubsubError = DocumentHelper.createElement(QName.get(
                    "nodeid-required", "http://jabber.org/protocol/pubsub#errors"));
            sendErrorPacket(iq, PacketError.Condition.bad_request, pubsubError);
            return;
        }
        else {
            // Look for the specified node
            node = service.getNode(nodeID);
            if (node == null) {
                // Node does not exist. Return item-not-found error
                sendErrorPacket(iq, PacketError.Condition.item_not_found, null);
                return;
            }
        }

        JID from = iq.getFrom();
        // TODO Assuming that owner is the bare JID (as defined in the JEP). This can be replaced with an explicit owner specified in the packet
        JID owner = new JID(from.toBareJID());
        if (!node.getPublisherModel().canPublish(node, owner) && !service.isServiceAdmin(owner)) {
            // Entity does not have sufficient privileges to publish to node
            sendErrorPacket(iq, PacketError.Condition.forbidden, null);
            return;
        }

        if (node.isCollectionNode()) {
            // Node is a collection node. Return feature-not-implemented error
            Element pubsubError = DocumentHelper.createElement(
                    QName.get("unsupported", "http://jabber.org/protocol/pubsub#errors"));
            pubsubError.addAttribute("feature", "publish");
            sendErrorPacket(iq, PacketError.Condition.feature_not_implemented, pubsubError);
            return;
        }

        LeafNode leafNode = (LeafNode) node;
        Iterator itemElements = publishElement.elementIterator("item");

        // Check that an item was included if node persist items or includes payload
        if (!itemElements.hasNext() && leafNode.isItemRequired()) {
            Element pubsubError = DocumentHelper.createElement(QName.get(
                    "item-required", "http://jabber.org/protocol/pubsub#errors"));
            sendErrorPacket(iq, PacketError.Condition.bad_request, pubsubError);
            return;
        }
        // Check that no item was included if node doesn't persist items and doesn't
        // includes payload
        if (itemElements.hasNext() && !leafNode.isItemRequired()) {
            Element pubsubError = DocumentHelper.createElement(QName.get(
                    "item-forbidden", "http://jabber.org/protocol/pubsub#errors"));
            sendErrorPacket(iq, PacketError.Condition.bad_request, pubsubError);
            return;
        }
        List<Element> items = new ArrayList<Element>();
        List entries;
        Element payload;
        while (itemElements.hasNext()) {
            Element item = (Element) itemElements.next();
            entries = item.elements();
            payload = entries.isEmpty() ? null : (Element) entries.get(0);
            // Check that a payload was included if node is configured to include payload
            // in notifications
            if (payload == null && leafNode.isPayloadDelivered()) {
                Element pubsubError = DocumentHelper.createElement(QName.get(
                        "payload-required", "http://jabber.org/protocol/pubsub#errors"));
                sendErrorPacket(iq, PacketError.Condition.bad_request, pubsubError);
                return;
            }
            // Check that the payload (if any) contains only one child element
            if (entries.size() > 1) {
                Element pubsubError = DocumentHelper.createElement(QName.get(
                        "invalid-payload", "http://jabber.org/protocol/pubsub#errors"));
                sendErrorPacket(iq, PacketError.Condition.bad_request, pubsubError);
                return;
            }
            items.add(item);
        }

        // Return success operation
        router.route(IQ.createResultIQ(iq));
        // Publish item and send event notifications to subscribers
        leafNode.publishItems(from, items);
    }

    private void deleteItems(IQ iq, Element retractElement) {
        String nodeID = retractElement.attributeValue("node");
        Node node;
        if (nodeID == null) {
            // No node was specified. Return bad_request error
            Element pubsubError = DocumentHelper.createElement(QName.get(
                    "nodeid-required", "http://jabber.org/protocol/pubsub#errors"));
            sendErrorPacket(iq, PacketError.Condition.bad_request, pubsubError);
            return;
        }
        else {
            // Look for the specified node
            node = service.getNode(nodeID);
            if (node == null) {
                // Node does not exist. Return item-not-found error
                sendErrorPacket(iq, PacketError.Condition.item_not_found, null);
                return;
            }
        }
        // Get the items to delete
        Iterator itemElements = retractElement.elementIterator("item");
        if (!itemElements.hasNext()) {
            Element pubsubError = DocumentHelper.createElement(QName.get(
                    "item-required", "http://jabber.org/protocol/pubsub#errors"));
            sendErrorPacket(iq, PacketError.Condition.bad_request, pubsubError);
            return;
        }

        if (node.isCollectionNode()) {
            // Cannot delete items from a collection node. Return an error.
            Element pubsubError = DocumentHelper.createElement(QName.get(
                    "unsupported", "http://jabber.org/protocol/pubsub#errors"));
            pubsubError.addAttribute("feature", "persistent-items");
            sendErrorPacket(iq, PacketError.Condition.feature_not_implemented, pubsubError);
            return;
        }
        LeafNode leafNode = (LeafNode) node;

        if (!leafNode.isItemRequired()) {
            // Cannot delete items from a leaf node that doesn't handle itemIDs. Return an error.
            Element pubsubError = DocumentHelper.createElement(QName.get(
                    "unsupported", "http://jabber.org/protocol/pubsub#errors"));
            pubsubError.addAttribute("feature", "persistent-items");
            sendErrorPacket(iq, PacketError.Condition.feature_not_implemented, pubsubError);
            return;
        }

        List<PublishedItem> items = new ArrayList<PublishedItem>();
        while (itemElements.hasNext()) {
            Element itemElement = (Element) itemElements.next();
            String itemID = itemElement.attributeValue("id");
            if (itemID != null) {
                PublishedItem item = node.getPublishedItem(itemID);
                if (item == null) {
                    // ItemID does not exist. Return item-not-found error
                    sendErrorPacket(iq, PacketError.Condition.item_not_found, null);
                    return;
                }
                else {
                    if (item.canDelete(iq.getFrom())) {
                        items.add(item);
                    }
                    else {
                        // Publisher does not have sufficient privileges to delete this item
                        sendErrorPacket(iq, PacketError.Condition.forbidden, null);
                        return;
                    }
                }
            }
            else {
                // No item ID was specified so return a bad_request error
                Element pubsubError = DocumentHelper.createElement(QName.get(
                        "item-required", "http://jabber.org/protocol/pubsub#errors"));
                sendErrorPacket(iq, PacketError.Condition.bad_request, pubsubError);
                return;
            }
        }
        // Send reply with success
        router.route(IQ.createResultIQ(iq));
        // Delete items and send subscribers a notification
        leafNode.deleteItems(items);
    }

    private void subscribeNode(IQ iq, Element childElement, Element subscribeElement) {
        String nodeID = subscribeElement.attributeValue("node");
        Node node;
        if (nodeID == null) {
            if (service.isCollectionNodesSupported()) {
                // Entity subscribes to root collection node
                node = service.getRootCollectionNode();
            }
            else {
                // Service does not have a root collection node so return a nodeid-required error
                Element pubsubError = DocumentHelper.createElement(QName.get(
                        "nodeid-required", "http://jabber.org/protocol/pubsub#errors"));
                sendErrorPacket(iq, PacketError.Condition.bad_request, pubsubError);
                return;
            }
        }
        else {
            // Look for the specified node
            node = service.getNode(nodeID);
            if (node == null) {
                // Node does not exist. Return item-not-found error
                sendErrorPacket(iq, PacketError.Condition.item_not_found, null);
                return;
            }
        }
        // Check if sender and subscriber JIDs match or if a valid "trusted proxy" is being used
        JID from = iq.getFrom();
        JID subscriberJID = new JID(subscribeElement.attributeValue("jid"));
        if (!from.toBareJID().equals(subscriberJID.toBareJID()) && !service.isServiceAdmin(from)) {
            // JIDs do not match and requestor is not a service admin so return an error
            Element pubsubError = DocumentHelper.createElement(
                    QName.get("invalid-jid", "http://jabber.org/protocol/pubsub#errors"));
            sendErrorPacket(iq, PacketError.Condition.bad_request, pubsubError);
            return;
        }
        // TODO Assumed that the owner of the subscription is the bare JID of the subscription JID. Waiting StPeter answer for explicit field.
        JID owner = new JID(subscriberJID.toBareJID());
        // Check if the node's access model allows the subscription to proceed
        AccessModel accessModel = node.getAccessModel();
        if (!accessModel.canSubscribe(node, owner, subscriberJID)) {
            sendErrorPacket(iq, accessModel.getSubsriptionError(),
                    accessModel.getSubsriptionErrorDetail());
            return;
        }
        // Check if the subscriber is an anonymous user
        if (!UserManager.getInstance().isRegisteredUser(subscriberJID)) {
            // Anonymous users cannot subscribe to the node. Return forbidden error
            sendErrorPacket(iq, PacketError.Condition.forbidden, null);
            return;
        }
        // Check if the subscription owner is a user with outcast affiliation