Add MUC room config extension SPI and disco query passthrough

xmppserver/src/main/java/org/jivesoftware/openfire/disco/DiscoItemsProvider.java

@@ -16,6 +16,7 @@
 
 package org.jivesoftware.openfire.disco;
 
+import org.dom4j.Element;
 import org.xmpp.packet.JID;
 
 import java.util.Iterator;
@@ -46,4 +47,18 @@ public interface DiscoItemsProvider {
      */
     Iterator<DiscoItem> getItems( String name, String node, JID senderJID );
 
+    /**
+     * Returns disco items, optionally using the full query element (for XEP-0462 type filtering, XEP-0499 metadata, etc.).
+     * The default implementation ignores the query element and delegates to {@link #getItems(String, String, JID)}.
+     *
+     * @param name the recipient JID's name.
+     * @param node the requested disco node.
+     * @param senderJID the XMPPAddress of user that sent the disco items request.
+     * @param query the full disco#items query element.
+     * @return an Iterator (of DiscoItem) with the target entity's items or null if none.
+     */
+    default Iterator<DiscoItem> getItems(String name, String node, JID senderJID, Element query) {
+        return getItems(name, node, senderJID);
+    }
+
 }

xmppserver/src/main/java/org/jivesoftware/openfire/disco/IQDiscoItemsHandler.java

@@ -159,8 +159,10 @@ public IQ handleIQ(IQ packet) {
             Element iq = packet.getChildElement();
             String node = iq.attributeValue("node");
 
-            // Check if we have items associated with the requested name and node
-            Iterator<DiscoItem> itemsItr = itemsProvider.getItems(name, node, packet.getFrom());
+            // Check if we have items associated with the requested name and node. Pass a defensive copy of the
+            // query element: providers may be third-party implementations, and mutating the live element would
+            // leak into the reply built below (and into anything else holding packet.getChildElement()).
+            Iterator<DiscoItem> itemsItr = itemsProvider.getItems(name, node, packet.getFrom(), iq.createCopy());
             if (itemsItr != null) {
                 reply.setChildElement(iq.createCopy());
                 Element queryElement = reply.getChildElement();

xmppserver/src/main/java/org/jivesoftware/openfire/muc/MUCRoomConfigExtension.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2026 Ignite Realtime Foundation. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.openfire.muc;
+
+import org.xmpp.forms.DataForm;
+
+import java.util.Collection;
+import java.util.Set;
+
+/**
+ * Allows plugins to contribute additional fields to MUC room configuration forms and room disco#info.
+ */
+public interface MUCRoomConfigExtension {
+
+    /**
+     * Adds extension-specific fields to the room owner configuration form.
+     *
+     * @param form the configuration form being built.
+     * @param room the room being configured.
+     */
+    default void contributeConfigForm(DataForm form, MUCRoom room) {
+    }
+
+    /**
+     * Populates extension-specific fields in the configuration form with current room values.
+     *
+     * @param form the configuration form being populated.
+     * @param room the room being configured.
+     */
+    default void populateConfigForm(DataForm form, MUCRoom room) {
+    }
+
+    /**
+     * Processes extension-specific fields from a submitted configuration form.
+     *
+     * @param completedForm the submitted configuration form.
+     * @param room the room being configured.
+     */
+    default void processConfigSubmit(DataForm completedForm, MUCRoom room) {
+    }
+
+    /**
+     * Contributes extension-specific disco#info features for a room. Invoked while building the room's
+     * disco#info feature list.
+     *
+     * @param features mutable collection of disco features to augment.
+     * @param room the room being described.
+     */
+    default void contributeRoomDiscoFeatures(Collection<String> features, MUCRoom room) {
+    }
+
+    /**
+     * Contributes extension-specific disco#info extended data forms for a room. Invoked while building the
+     * room's extended disco#info (XEP-0128) forms; the set already contains the room's {@code muc#roominfo}
+     * form, which an extension may augment or supplement with additional forms.
+     *
+     * @param forms mutable set of extended data forms to augment.
+     * @param room the room being described.
+     */
+    default void contributeRoomDiscoForms(Set<DataForm> forms, MUCRoom room) {
+    }
+}

xmppserver/src/main/java/org/jivesoftware/openfire/muc/MUCRoomConfigExtensionManager.java

@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2026 Ignite Realtime Foundation. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.openfire.muc;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.xmpp.forms.DataForm;
+
+import java.util.Collection;
+import java.util.Set;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.function.Consumer;
+
+/**
+ * Registry for {@link MUCRoomConfigExtension} implementations contributed by plugins.
+ */
+public final class MUCRoomConfigExtensionManager {
+
+    private static final Logger Log = LoggerFactory.getLogger(MUCRoomConfigExtensionManager.class);
+
+    private static final MUCRoomConfigExtensionManager INSTANCE = new MUCRoomConfigExtensionManager();
+
+    private final CopyOnWriteArrayList<MUCRoomConfigExtension> extensions = new CopyOnWriteArrayList<>();
+
+    private MUCRoomConfigExtensionManager() {
+    }
+
+    public static MUCRoomConfigExtensionManager getInstance() {
+        return INSTANCE;
+    }
+
+    public void register(MUCRoomConfigExtension extension) {
+        if (extension != null) {
+            extensions.addIfAbsent(extension);
+        }
+    }
+
+    public void unregister(MUCRoomConfigExtension extension) {
+        extensions.remove(extension);
+    }
+
+    public void contributeConfigForm(DataForm form, MUCRoom room) {
+        forEachExtension("contributing to the config form", room, extension -> extension.contributeConfigForm(form, room));
+    }
+
+    public void populateConfigForm(DataForm form, MUCRoom room) {
+        forEachExtension("populating the config form", room, extension -> extension.populateConfigForm(form, room));
+    }
+
+    public void processConfigSubmit(DataForm completedForm, MUCRoom room) {
+        forEachExtension("processing the config submission", room, extension -> extension.processConfigSubmit(completedForm, room));
+    }
+
+    public void contributeRoomDiscoFeatures(Collection<String> features, MUCRoom room) {
+        forEachExtension("contributing disco#info features", room, extension -> extension.contributeRoomDiscoFeatures(features, room));
+    }
+
+    public void contributeRoomDiscoForms(Set<DataForm> forms, MUCRoom room) {
+        forEachExtension("contributing disco#info forms", room, extension -> extension.contributeRoomDiscoForms(forms, room));
+    }
+
+    /**
+     * Applies an operation to every registered extension, isolating failures: an exception thrown by one
+     * (third-party) extension is logged and does not prevent the remaining extensions from running, nor
+     * does it break the room configuration / disco handling that invoked this manager.
+     */
+    private void forEachExtension(final String action, final MUCRoom room, final Consumer<MUCRoomConfigExtension> operation) {
+        for (final MUCRoomConfigExtension extension : extensions) {
+            try {
+                operation.accept(extension);
+            } catch (final RuntimeException e) {
+                Log.warn("MUC room config extension {} threw an exception while {} for room {}",
+                    extension, action, room == null ? null : room.getName(), e);
+            }
+        }
+    }
+}

xmppserver/src/main/java/org/jivesoftware/openfire/muc/spi/IQOwnerHandler.java

@@ -419,6 +419,8 @@ else if ( passwordChanged )
             room.setRegistrationEnabled( parseFirstValueAsBoolean( field, true ) );
         }
 
+        MUCRoomConfigExtensionManager.getInstance().processConfigSubmit(completedForm, room);
+
         // Update the modification date to reflect the last time when the room's configuration
         // was modified
         room.setModificationDate(new Date());
@@ -622,6 +624,8 @@ private Element generateProbeResult(Locale preferredLocale) {
                 LocaleUtils.getLocalizedString("muc.form.conf.owner_roomowners", preferredLocale),
                 Type.jid_multi);
 
+        MUCRoomConfigExtensionManager.getInstance().contributeConfigForm(configurationForm, room);
+
         // Add room-specific data values to the form.
         synchronized (room) {
             FormField field = configurationForm.getField("muc#roomconfig_roomname");
@@ -741,6 +745,8 @@ private Element generateProbeResult(Locale preferredLocale) {
                     field.addValue(jid.toString());
                 }
             }
+
+            MUCRoomConfigExtensionManager.getInstance().populateConfigForm(configurationForm, room);
         }
 
         final Element element = DocumentHelper.createElement(QName.get("query",

xmppserver/src/main/java/org/jivesoftware/openfire/muc/spi/MultiUserChatServiceImpl.java

@@ -3129,6 +3129,7 @@ else if (name != null && node == null) {
                 }
                 features.add( "urn:xmpp:sid:0" );
                 features.add( "urn:xmpp:occupant-id:0" );
+                MUCRoomConfigExtensionManager.getInstance().contributeRoomDiscoFeatures(features, room);
             }
         }
         return features.iterator();
@@ -3197,6 +3198,7 @@ public Set<DataForm> getExtendedInfos(String name, String node, JID senderJID) {
 
                 final Set<DataForm> dataForms = new HashSet<>();
                 dataForms.add(dataForm);
+                MUCRoomConfigExtensionManager.getInstance().contributeRoomDiscoForms(dataForms, room);
                 return dataForms;
             }
         }

xmppserver/src/test/java/org/jivesoftware/openfire/muc/MUCRoomConfigExtensionManagerTest.java

@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2026 Ignite Realtime Foundation. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.openfire.muc;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+import org.xmpp.forms.DataForm;
+import org.xmpp.forms.FormField;
+
+import java.util.HashSet;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.mock;
+
+class MUCRoomConfigExtensionManagerTest {
+
+    private DataForm processedForm;
+    private MUCRoom processedRoom;
+
+    @AfterEach
+    void cleanup() {
+        MUCRoomConfigExtensionManager.getInstance().unregister(testExtension);
+        MUCRoomConfigExtensionManager.getInstance().unregister(throwingExtension);
+    }
+
+    private final MUCRoomConfigExtension throwingExtension = new MUCRoomConfigExtension() {
+        @Override
+        public void contributeConfigForm(final DataForm form, final MUCRoom room) {
+            throw new RuntimeException("boom");
+        }
+    };
+
+    private final MUCRoomConfigExtension testExtension = new MUCRoomConfigExtension() {
+        @Override
+        public void contributeConfigForm(final DataForm form, final MUCRoom room) {
+            form.addField("test#field", "Test", FormField.Type.text_single);
+        }
+
+        @Override
+        public void populateConfigForm(final DataForm form, final MUCRoom room) {
+            form.getField("test#field").addValue("value");
+        }
+
+        @Override
+        public void processConfigSubmit(final DataForm completedForm, final MUCRoom room) {
+            processedForm = completedForm;
+            processedRoom = room;
+        }
+
+        @Override
+        public void contributeRoomDiscoFeatures(final java.util.Collection<String> features, final MUCRoom room) {
+            features.add("urn:xmpp:test:0");
+        }
+
+        @Override
+        public void contributeRoomDiscoForms(final java.util.Set<DataForm> forms, final MUCRoom room) {
+            final DataForm form = new DataForm(DataForm.Type.result);
+            form.addField("FORM_TYPE", null, FormField.Type.hidden).addValue("urn:xmpp:test:0");
+            forms.add(form);
+        }
+    };
+
+    @Test
+    void registeredExtensionContributesConfigForm() {
+        MUCRoomConfigExtensionManager.getInstance().register(testExtension);
+        final DataForm form = new DataForm(DataForm.Type.form);
+        final MUCRoom room = mock(MUCRoom.class);
+        MUCRoomConfigExtensionManager.getInstance().contributeConfigForm(form, room);
+        assertNotNull(form.getField("test#field"));
+
+        MUCRoomConfigExtensionManager.getInstance().populateConfigForm(form, room);
+        assertEquals("value", form.getField("test#field").getFirstValue());
+
+        MUCRoomConfigExtensionManager.getInstance().processConfigSubmit(form, room);
+        assertSame(form, processedForm);
+        assertSame(room, processedRoom);
+    }
+
+    @Test
+    void registeredExtensionContributesDisco() {
+        MUCRoomConfigExtensionManager.getInstance().register(testExtension);
+        final var room = mock(MUCRoom.class);
+        final var features = new HashSet<String>();
+        final var forms = new HashSet<DataForm>();
+        MUCRoomConfigExtensionManager.getInstance().contributeRoomDiscoFeatures(features, room);
+        MUCRoomConfigExtensionManager.getInstance().contributeRoomDiscoForms(forms, room);
+        assertTrue(features.contains("urn:xmpp:test:0"));
+        // Assert the specific form this extension contributed, rather than mere non-emptiness, so the test
+        // does not depend on what else may be registered on the process-wide singleton.
+        assertTrue(forms.stream().anyMatch(f -> {
+            final FormField formType = f.getField("FORM_TYPE");
+            return formType != null && "urn:xmpp:test:0".equals(formType.getFirstValue());
+        }));
+    }
+
+    @Test
+    void throwingExtensionIsIsolated() {
+        // A throwing extension must neither propagate nor prevent other extensions from running.
+        MUCRoomConfigExtensionManager.getInstance().register(throwingExtension);
+        MUCRoomConfigExtensionManager.getInstance().register(testExtension);
+        final DataForm form = new DataForm(DataForm.Type.form);
+        final MUCRoom room = mock(MUCRoom.class);
+        assertDoesNotThrow(() -> MUCRoomConfigExtensionManager.getInstance().contributeConfigForm(form, room));
+        assertNotNull(form.getField("test#field"));
+    }
+}