Tell each VM to flush their DNS cache.

bug:3095357
Change-Id: I93de24e3e5a7d8b94d55f4facfffc863a2b8c202

7 files changed, 55 insertions, 1 deletions

diff --git a/core/java/android/app/ActivityThread.java b/core/java/android/app/ActivityThread.java
index 47efddb66628..174b6da6bdc7 100644
--- a/core/java/android/app/ActivityThread.java
+++ b/core/java/android/app/ActivityThread.java
@@ -85,6 +85,7 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.lang.ref.WeakReference;
+import java.net.InetAddress;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -585,6 +586,11 @@ public final class ActivityThread {
             TimeZone.setDefault(null);
         }
 
+        public void clearDnsCache() {
+            // a non-standard API to get this to libcore
+            InetAddress.clearDnsCache();
+        }
+
         public void processInBackground() {
             mH.removeMessages(H.GC_WHEN_IDLE);
             mH.sendMessage(mH.obtainMessage(H.GC_WHEN_IDLE));
diff --git a/core/java/android/app/ApplicationThreadNative.java b/core/java/android/app/ApplicationThreadNative.java
index 95689fc3df42..b19fb5979e1c 100644
--- a/core/java/android/app/ApplicationThreadNative.java
+++ b/core/java/android/app/ApplicationThreadNative.java
@@ -291,6 +291,12 @@ public abstract class ApplicationThreadNative extends Binder
             return true;
         }
 
+        case CLEAR_DNS_CACHE_TRANSACTION: {
+            data.enforceInterface(IApplicationThread.descriptor);
+            clearDnsCache();
+            return true;
+        }
+
         case PROCESS_IN_BACKGROUND_TRANSACTION: {
             data.enforceInterface(IApplicationThread.descriptor);
             processInBackground();
@@ -744,6 +750,14 @@ class ApplicationThreadProxy implements IApplicationThread {
         data.recycle();
     }
 
+    public void clearDnsCache() throws RemoteException {
+        Parcel data = Parcel.obtain();
+        data.writeInterfaceToken(IApplicationThread.descriptor);
+        mRemote.transact(CLEAR_DNS_CACHE_TRANSACTION, data, null,
+                IBinder.FLAG_ONEWAY);
+        data.recycle();
+    }
+
     public void processInBackground() throws RemoteException {
         Parcel data = Parcel.obtain();
         data.writeInterfaceToken(IApplicationThread.descriptor);
@@ -884,4 +898,3 @@ class ApplicationThreadProxy implements IApplicationThread {
         data.recycle();
     }
 }
-
diff --git a/core/java/android/app/IApplicationThread.java b/core/java/android/app/IApplicationThread.java
index 1f8a7c58325f..830c7024b5d2 100644
--- a/core/java/android/app/IApplicationThread.java
+++ b/core/java/android/app/IApplicationThread.java
@@ -87,6 +87,7 @@ public interface IApplicationThread extends IInterface {
     void requestThumbnail(IBinder token) throws RemoteException;
     void scheduleConfigurationChanged(Configuration config) throws RemoteException;
     void updateTimeZone() throws RemoteException;
+    void clearDnsCache() throws RemoteException;
     void processInBackground() throws RemoteException;
     void dumpService(FileDescriptor fd, IBinder servicetoken, String[] args)
             throws RemoteException;
@@ -146,4 +147,5 @@ public interface IApplicationThread extends IInterface {
     int SCHEDULE_CRASH_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+34;
     int DUMP_HEAP_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+35;
     int DUMP_ACTIVITY_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+36;
+    int CLEAR_DNS_CACHE_TRANSACTION = IBinder.FIRST_CALL_TRANSACTION+37;
 }
diff --git a/core/java/android/content/Intent.java b/core/java/android/content/Intent.java
index ac6b1479fd00..4b6333e3b7e1 100644
--- a/core/java/android/content/Intent.java
+++ b/core/java/android/content/Intent.java
@@ -1223,6 +1223,13 @@ public class Intent implements Parcelable, Cloneable {
     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
     public static final String ACTION_TIMEZONE_CHANGED = "android.intent.action.TIMEZONE_CHANGED";
     /**
+     * Clear DNS Cache Action: This is broadcast when networks have changed and old
+     * DNS entries should be tossed.
+     * @hide
+     */
+    @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
+    public static final String ACTION_CLEAR_DNS_CACHE = "android.intent.action.CLEAR_DNS_CACHE";
+    /**
      * Alarm Changed Action: This is broadcast when the AlarmClock
      * application's alarm is set or unset.  It is used by the
      * AlarmClock application and the StatusBar service.
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 3331e1bba03c..43f175f894b8 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -91,6 +91,7 @@
     <protected-broadcast android:name="android.nfc.action.TAG_DISCOVERED" />
     <protected-broadcast android:name="android.nfc.action.LLCP_LINK_STATE_CHANGED" />
     <protected-broadcast android:name="android.nfc.action.TRANSACTION_DETECTED" />
+    <protected-broadcast android:name="android.intent.action.CLEAR_DNS_CACHE" />
 
     <!-- ====================================== -->
     <!-- Permissions for things that cost money -->
diff --git a/services/java/com/android/server/ConnectivityService.java b/services/java/com/android/server/ConnectivityService.java
index ee0cc4bd4b82..c18262e1d388 100644
--- a/services/java/com/android/server/ConnectivityService.java
+++ b/services/java/com/android/server/ConnectivityService.java
@@ -1596,6 +1596,12 @@ public class ConnectivityService extends IConnectivityManager.Stub {
             } catch (NumberFormatException e) {}
         }
         SystemProperties.set("net.dnschange", "" + (n+1));
+        /*
+         * Tell the VMs to toss their DNS caches
+         */
+        Intent intent = new Intent(Intent.ACTION_CLEAR_DNS_CACHE);
+        intent.addFlags(Intent.FLAG_RECEIVER_REPLACE_PENDING);
+        mContext.sendBroadcast(intent);
     }
 
     private void handleDnsConfigurationChange(int netType) {
diff --git a/services/java/com/android/server/am/ActivityManagerService.java b/services/java/com/android/server/am/ActivityManagerService.java
index 60b2b67d1cb6..7905dc6399e6 100644
--- a/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java
@@ -959,6 +959,7 @@ public final class ActivityManagerService extends ActivityManagerNative
     static final int CANCEL_HEAVY_NOTIFICATION_MSG = 25;
     static final int SHOW_STRICT_MODE_VIOLATION_MSG = 26;
     static final int CHECK_EXCESSIVE_WAKE_LOCKS_MSG = 27;
+    static final int CLEAR_DNS_CACHE = 28;
 
     AlertDialog mUidAlert;
 
@@ -1110,6 +1111,20 @@ public final class ActivityManagerService extends ActivityManagerNative
                     }
                 }
             } break;
+            case CLEAR_DNS_CACHE: {
+                synchronized (ActivityManagerService.this) {
+                    for (int i = mLruProcesses.size() - 1 ; i >= 0 ; i--) {
+                        ProcessRecord r = mLruProcesses.get(i);
+                        if (r.thread != null) {
+                            try {
+                                r.thread.clearDnsCache();
+                            } catch (RemoteException ex) {
+                                Slog.w(TAG, "Failed to clear dns cache for: " + r.info.processName);
+                            }
+                        }
+                    }
+                }
+            } break;
             case SHOW_UID_ERROR_MSG: {
                 // XXX This is a temporary dialog, no need to localize.
                 AlertDialog d = new BaseErrorDialog(mContext);
@@ -10373,6 +10388,10 @@ public final class ActivityManagerService extends ActivityManagerNative
             mHandler.sendEmptyMessage(UPDATE_TIME_ZONE);
         }
 
+        if (intent.ACTION_CLEAR_DNS_CACHE.equals(intent.getAction())) {
+            mHandler.sendEmptyMessage(CLEAR_DNS_CACHE);
+        }
+
         /*
          * Prevent non-system code (defined here to be non-persistent
          * processes) from sending protected broadcasts.