From 4ab0a63b36de32fac4bee441e4c5697431357595 Mon Sep 17 00:00:00 2001
From: Chiachang Wang <chiachangwang@google.com>
Date: Thu, 25 Mar 2021 17:51:00 +0800
Subject: [PATCH] Add network disconnected callback

Create a network callback to notify network agent after the
native network being destroyed by netd which means the network
is fully disconnected. The NetworkAgent may handle this event
after sending disconnect state to ConnectivityService to proceed
its pending works that have to be done after it.

Bug: 178725261
Test: make update-api
Change-Id: I602ff2c688909473b03b72c9407d4286608cff4c
CTS-Coverage-Bug: 178725261
---
 framework/api/system-current.txt              |  1 +
 framework/src/android/net/INetworkAgent.aidl  |  1 +
 framework/src/android/net/NetworkAgent.java   | 23 +++++++++++++++++++
 .../android/server/ConnectivityService.java   |  1 +
 .../server/connectivity/NetworkAgentInfo.java | 11 +++++++++
 5 files changed, 37 insertions(+)

diff --git a/framework/api/system-current.txt b/framework/api/system-current.txt
index c1395d1c9b..593698e097 100644
--- a/framework/api/system-current.txt
+++ b/framework/api/system-current.txt
@@ -219,6 +219,7 @@ package android.net {
     method public void onAutomaticReconnectDisabled();
     method public void onBandwidthUpdateRequested();
     method public void onNetworkCreated();
+    method public void onNetworkDisconnected();
     method public void onNetworkUnwanted();
     method public void onQosCallbackRegistered(int, @NonNull android.net.QosFilter);
     method public void onQosCallbackUnregistered(int);
diff --git a/framework/src/android/net/INetworkAgent.aidl b/framework/src/android/net/INetworkAgent.aidl
index 078acbd8fe..f9d399459e 100644
--- a/framework/src/android/net/INetworkAgent.aidl
+++ b/framework/src/android/net/INetworkAgent.aidl
@@ -47,4 +47,5 @@ oneway interface INetworkAgent {
     void onQosFilterCallbackRegistered(int qosCallbackId, in QosFilterParcelable filterParcel);
     void onQosCallbackUnregistered(int qosCallbackId);
     void onNetworkCreated();
+    void onNetworkDisconnected();
 }
diff --git a/framework/src/android/net/NetworkAgent.java b/framework/src/android/net/NetworkAgent.java
index adb04cf9a4..6b55bb771c 100644
--- a/framework/src/android/net/NetworkAgent.java
+++ b/framework/src/android/net/NetworkAgent.java
@@ -370,6 +370,14 @@ public abstract class NetworkAgent {
      */
     public static final int CMD_NETWORK_CREATED = BASE + 22;
 
+    /**
+     * Sent by ConnectivityService to {@link NetworkAgent} to inform the agent that its native
+     * network was destroyed.
+     *
+     * @hide
+     */
+    public static final int CMD_NETWORK_DISCONNECTED = BASE + 23;
+
     private static NetworkInfo getLegacyNetworkInfo(final NetworkAgentConfig config) {
         final NetworkInfo ni = new NetworkInfo(config.legacyType, config.legacySubType,
                 config.legacyTypeName, config.legacySubTypeName);
@@ -573,6 +581,10 @@ public abstract class NetworkAgent {
                     onNetworkCreated();
                     break;
                 }
+                case CMD_NETWORK_DISCONNECTED: {
+                    onNetworkDisconnected();
+                    break;
+                }
             }
         }
     }
@@ -718,6 +730,11 @@ public abstract class NetworkAgent {
         public void onNetworkCreated() {
             mHandler.sendMessage(mHandler.obtainMessage(CMD_NETWORK_CREATED));
         }
+
+        @Override
+        public void onNetworkDisconnected() {
+            mHandler.sendMessage(mHandler.obtainMessage(CMD_NETWORK_DISCONNECTED));
+        }
     }
 
     /**
@@ -1032,6 +1049,12 @@ public abstract class NetworkAgent {
      */
     public void onNetworkCreated() {}
 
+
+    /**
+     * Called when ConnectivityService has successfully destroy this NetworkAgent's native network.
+     */
+    public void onNetworkDisconnected() {}
+
     /**
      * Requests that the network hardware send the specified packet at the specified interval.
      *
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 9c80e52c21..8bb9ce940c 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -3716,6 +3716,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
             mDnsManager.removeNetwork(nai.network);
         }
         mNetIdManager.releaseNetId(nai.network.getNetId());
+        nai.onNetworkDisconnected();
     }
 
     private boolean createNativeNetwork(@NonNull NetworkAgentInfo networkAgent) {
diff --git a/services/core/java/com/android/server/connectivity/NetworkAgentInfo.java b/services/core/java/com/android/server/connectivity/NetworkAgentInfo.java
index 4963353993..97df5bff49 100644
--- a/services/core/java/com/android/server/connectivity/NetworkAgentInfo.java
+++ b/services/core/java/com/android/server/connectivity/NetworkAgentInfo.java
@@ -588,6 +588,17 @@ public class NetworkAgentInfo implements Comparable<NetworkAgentInfo> {
         }
     }
 
+    /**
+     * Notify the NetworkAgent that the network is disconnected and destroyed.
+     */
+    public void onNetworkDisconnected() {
+        try {
+            networkAgent.onNetworkDisconnected();
+        } catch (RemoteException e) {
+            Log.e(TAG, "Error sending network disconnected event", e);
+        }
+    }
+
     // TODO: consider moving out of NetworkAgentInfo into its own class
     private class NetworkAgentMessageHandler extends INetworkAgentRegistry.Stub {
         private final Handler mHandler;