Send OffloadServiceInfos when registerOffloadEngine is called

When the OffloadEngine is registered, it should get notice about all the
currently offloaded service.

Bug: 297314970
Test: atest CtsNetTestCases
Change-Id: I1b977a40476a1f5c30a075b559e72656a42865ae
diff --git a/service-t/src/com/android/server/NsdService.java b/service-t/src/com/android/server/NsdService.java
index eb73ee5..69d5c5b 100644
--- a/service-t/src/com/android/server/NsdService.java
+++ b/service-t/src/com/android/server/NsdService.java
@@ -1162,7 +1162,7 @@
                         // TODO: Limits the number of registrations created by a given class.
                         mOffloadEngines.register(offloadEngineInfo.mOffloadEngine,
                                 offloadEngineInfo);
-                        // TODO: Sends all the existing OffloadServiceInfos back.
+                        sendAllOffloadServiceInfos(offloadEngineInfo);
                         break;
                     case NsdManager.UNREGISTER_OFFLOAD_ENGINE:
                         mOffloadEngines.unregister((IOffloadEngine) msg.obj);
@@ -1834,6 +1834,21 @@
         }
     }
 
+    private void sendAllOffloadServiceInfos(@NonNull OffloadEngineInfo offloadEngineInfo) {
+        final String targetInterface = offloadEngineInfo.mInterfaceName;
+        final IOffloadEngine offloadEngine = offloadEngineInfo.mOffloadEngine;
+        final List<MdnsAdvertiser.OffloadServiceInfoWrapper> offloadWrappers =
+                mAdvertiser.getAllInterfaceOffloadServiceInfos(targetInterface);
+        for (MdnsAdvertiser.OffloadServiceInfoWrapper wrapper : offloadWrappers) {
+            try {
+                offloadEngine.onOffloadServiceUpdated(wrapper.mOffloadServiceInfo);
+            } catch (RemoteException e) {
+                // Can happen in regular cases, do not log a stacktrace
+                Log.i(TAG, "Failed to send offload callback, remote died: " + e.getMessage());
+            }
+        }
+    }
+
     private void sendOffloadServiceInfosUpdate(@NonNull String targetInterfaceName,
             @NonNull OffloadServiceInfo offloadServiceInfo, boolean isRemove) {
         final int count = mOffloadEngines.beginBroadcast();
@@ -1857,7 +1872,7 @@
                     }
                 } catch (RemoteException e) {
                     // Can happen in regular cases, do not log a stacktrace
-                    Log.i(TAG, "Failed to send offload callback, remote died", e);
+                    Log.i(TAG, "Failed to send offload callback, remote died: " + e.getMessage());
                 }
             }
         } finally {
diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsAdvertiser.java b/service-t/src/com/android/server/connectivity/mdns/MdnsAdvertiser.java
index dd72d11..f43df45 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsAdvertiser.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsAdvertiser.java
@@ -37,6 +37,7 @@
 import com.android.server.connectivity.mdns.util.MdnsUtils;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
@@ -117,6 +118,17 @@
         }
     }
 
+    /**
+     * Gets the current status of the OffloadServiceInfos per interface.
+     * @param interfaceName the target interfaceName
+     * @return the list of current offloaded services.
+     */
+    @NonNull
+    public List<OffloadServiceInfoWrapper> getAllInterfaceOffloadServiceInfos(
+            @NonNull String interfaceName) {
+        return mInterfaceOffloadServices.getOrDefault(interfaceName, Collections.emptyList());
+    }
+
     private final MdnsInterfaceAdvertiser.Callback mInterfaceAdvertiserCb =
             new MdnsInterfaceAdvertiser.Callback() {
         @Override
@@ -385,9 +397,12 @@
         }
     }
 
-    private static class OffloadServiceInfoWrapper {
-        private final @NonNull OffloadServiceInfo mOffloadServiceInfo;
-        private final int mServiceId;
+    /**
+     * The wrapper class for OffloadServiceInfo including the serviceId.
+     */
+    public static class OffloadServiceInfoWrapper {
+        public final @NonNull OffloadServiceInfo mOffloadServiceInfo;
+        public final int mServiceId;
 
         OffloadServiceInfoWrapper(int serviceId, OffloadServiceInfo offloadServiceInfo) {
             mOffloadServiceInfo = offloadServiceInfo;