[Work in Progress 🚧] Add Gateway support at Server Side

leshan-integration-tests/src/test/java/org/eclipse/leshan/integration/tests/server/redis/RedisRegistrationStoreTest.java

@@ -55,6 +55,7 @@
 import org.eclipse.leshan.server.endpoint.EffectiveEndpointUriProvider;
 import org.eclipse.leshan.server.observation.LwM2mNotificationReceiver;
 import org.eclipse.leshan.server.profile.ClientProfile;
+import org.eclipse.leshan.server.registration.DeviceRegistration;
 import org.eclipse.leshan.server.registration.Registration;
 import org.eclipse.leshan.server.registration.RegistrationStore;
 import org.eclipse.leshan.transport.californium.ObserveUtil;
@@ -185,7 +186,7 @@ public void remove_observation() {
     }
 
     private void givenASimpleRegistration(Long lifetime) {
-        Registration.Builder builder = new Registration.Builder(registrationId, ep,
+        DeviceRegistration.Builder builder = new DeviceRegistration.Builder(registrationId, ep,
                 new IpPeer(new InetSocketAddress(address, port)), uriHandler.createUri("coap://localhost:5683"));
 
         registration = builder.lifeTimeInSec(lifetime).smsNumber(sms).bindingMode(binding).objectLinks(objectLinks)

leshan-lwm2m-core/src/main/java/org/eclipse/leshan/core/link/LinkUtil.java

@@ -0,0 +1,70 @@
+/*******************************************************************************
+ * Copyright (c) 2026 Sierra Wireless and others.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v2.0
+ * and Eclipse Distribution License v1.0 which accompany this distribution.
+ *
+ * The Eclipse Public License is available at
+ *    http://www.eclipse.org/legal/epl-v20.html
+ * and the Eclipse Distribution License is available at
+ *    http://www.eclipse.org/org/documents/edl-v10.html.
+ *
+ * Contributors:
+ *     Sierra Wireless - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.leshan.core.link;
+
+import java.util.Arrays;
+
+import org.eclipse.leshan.core.util.StringUtils;
+
+public final class LinkUtil {
+
+    @SuppressWarnings({ "java:S3776", "java:S1168" })
+    public static Link[] sort(Link[] linksToSort) {
+        // sort the list of objects
+        if (linksToSort == null) {
+            return null;
+        }
+
+        Link[] res = Arrays.copyOf(linksToSort, linksToSort.length);
+
+        Arrays.sort(res, (o1, o2) -> {
+            if (o1 == null && o2 == null)
+                return 0;
+            if (o1 == null)
+                return -1;
+            if (o2 == null)
+                return 1;
+            // by URL
+            String[] url1 = o1.getUriReference().split("/");
+            String[] url2 = o2.getUriReference().split("/");
+
+            for (int i = 0; i < url1.length && i < url2.length; i++) {
+                // is it two numbers?
+                if (isNumber(url1[i]) && isNumber(url2[i])) {
+                    int cmp = Integer.parseInt(url1[i]) - Integer.parseInt(url2[i]);
+                    if (cmp != 0) {
+                        return cmp;
+                    }
+                } else {
+
+                    int v = url1[i].compareTo(url2[i]);
+
+                    if (v != 0) {
+                        return v;
+                    }
+                }
+            }
+
+            return url1.length - url2.length;
+        });
+
+        return res;
+    }
+
+    private static boolean isNumber(String s) {
+        return !StringUtils.isEmpty(s) && StringUtils.isNumeric(s);
+    }
+}

leshan-lwm2m-server-redis/src/main/java/org/eclipse/leshan/server/redis/serialization/RegistrationSerDes.java

@@ -45,6 +45,7 @@
 import org.eclipse.leshan.core.node.LwM2mPath;
 import org.eclipse.leshan.core.request.BindingMode;
 import org.eclipse.leshan.core.request.ContentFormat;
+import org.eclipse.leshan.server.registration.DeviceRegistration;
 import org.eclipse.leshan.server.registration.Registration;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
@@ -180,8 +181,8 @@ public Registration deserialize(JsonNode jObj) {
                             jObj.get("epUri").asText(), jObj.get("regId").asText(), jObj.get("ep").asText()));
         }
 
-        Registration.Builder b = new Registration.Builder(jObj.get("regId").asText(), jObj.get("ep").asText(),
-                peerSerDes.deserialize(jObj.get("transportdata")), endpointUri);
+        DeviceRegistration.Builder b = new DeviceRegistration.Builder(jObj.get("regId").asText(),
+                jObj.get("ep").asText(), peerSerDes.deserialize(jObj.get("transportdata")), endpointUri);
 
         b.bindingMode(BindingMode.parse(jObj.get("bnd").asText()));
         if (jObj.get("qm") != null)

leshan-lwm2m-server-redis/src/test/java/org/eclipse/leshan/server/redis/serialization/RegistrationSerDesTest.java

@@ -36,6 +36,7 @@
 import org.eclipse.leshan.core.peer.IpPeer;
 import org.eclipse.leshan.core.request.ContentFormat;
 import org.eclipse.leshan.server.registration.DefaultRegistrationDataExtractor;
+import org.eclipse.leshan.server.registration.DeviceRegistration;
 import org.eclipse.leshan.server.registration.Registration;
 import org.eclipse.leshan.server.registration.RegistrationDataExtractor.RegistrationData;
 import org.junit.jupiter.api.Test;
@@ -56,7 +57,7 @@ void ser_and_des_are_equals() {
         objs[0] = new Link("/0/1024/2", attrs);
         objs[1] = new Link("/0/2");
 
-        Registration.Builder builder = new Registration.Builder("registrationId", "endpoint",
+        DeviceRegistration.Builder builder = new DeviceRegistration.Builder("registrationId", "endpoint",
                 new IpPeer(new InetSocketAddress(Inet4Address.getLoopbackAddress(), 1)),
                 uriHandler.createUri("coap://localhost:5683")).objectLinks(objs).rootPath("/")
                         .supportedContentFormats(ContentFormat.TLV, ContentFormat.TEXT);
@@ -94,7 +95,7 @@ void ser_and_des_are_equals_with_app_data() {
         appData.put("string", "string test");
         appData.put("null", null);
 
-        Registration.Builder builder = new Registration.Builder("registrationId", "endpoint",
+        DeviceRegistration.Builder builder = new DeviceRegistration.Builder("registrationId", "endpoint",
                 new IpPeer(new InetSocketAddress(Inet4Address.getLoopbackAddress(), 1)),
                 uriHandler.createUri("coap://localhost:5683")).objectLinks(objs).rootPath("/")
                         .supportedContentFormats(ContentFormat.TLV, ContentFormat.TEXT).customRegistrationData(appData);

leshan-lwm2m-server/src/main/java/org/eclipse/leshan/server/registration/Deregistration.java

@@ -17,6 +17,7 @@
 
 import java.util.Collection;
 import java.util.Collections;
+import java.util.List;
 
 import org.eclipse.leshan.core.observation.Observation;
 
@@ -25,16 +26,28 @@
  *
  * @see RegistrationStore
  */
-public class Deregistration {
-    final Registration registration;
-    final Collection<Observation> observations;
+public class Deregistration implements RegistrationModification {
+    private final Registration registration;
+    private final Collection<Observation> observations;
+    private final List<Deregistration> childrenDeregistration;
 
     public Deregistration(Registration registration, Collection<Observation> observations) {
+        this(registration, observations, null);
+    }
+
+    public Deregistration(Registration registration, Collection<Observation> observations,
+            List<Deregistration> childrenDeregistration) {
         this.registration = registration;
-        if (observations == null)
+        if (observations == null) {
             this.observations = Collections.emptyList();
-        else
+        } else {
             this.observations = observations;
+        }
+        if (childrenDeregistration == null) {
+            this.childrenDeregistration = Collections.emptyList();
+        } else {
+            this.childrenDeregistration = childrenDeregistration;
+        }
     }
 
     public Registration getRegistration() {
@@ -44,4 +57,11 @@ public Registration getRegistration() {
     public Collection<Observation> getObservations() {
         return observations;
     }
+
+    /**
+     * if {@link #getRegistration()} is a gateway then return all de-registration about its children.
+     */
+    public List<Deregistration> getChildrenDeRegistration() {
+        return childrenDeregistration;
+    }
 }