Network data activity change intent for network interfaces.

The activity notification is received from netd, an intent
DATA_ACTIVITY_CHANGE is then raised for other part of the system to
consume.

Change-Id: Idfcc4763c51c5b314c57f546c12557082f06bebf

services/java/com/android/server/NetworkManagementService.java

@@ -279,6 +279,20 @@ public class NetworkManagementService extends INetworkManagementService.Stub
         mObservers.finishBroadcast();
     }
 
+    /**
+     * Notify our observers of a change in the data activity state of the interface
+     */
+    private void notifyInterfaceClassActivity(String label, boolean active) {
+        final int length = mObservers.beginBroadcast();
+        for (int i = 0; i < length; i++) {
+            try {
+                mObservers.getBroadcastItem(i).interfaceClassDataActivityChanged(label, active);
+            } catch (RemoteException e) {
+            }
+        }
+        mObservers.finishBroadcast();
+    }
+
     /**
      * Prepare native daemon once connected, enabling modules and pushing any
      * existing in-memory rules.
@@ -405,6 +419,19 @@ public class NetworkManagementService extends INetworkManagementService.Stub
                     throw new IllegalStateException(
                             String.format("Invalid event from daemon (%s)", raw));
                     // break;
+            case NetdResponseCode.InterfaceClassActivity:
+                    /*
+                     * An network interface class state changed (active/idle)
+                     * Format: "NNN IfaceClass <active/idle> <label>"
+                     */
+                    if (cooked.length < 4 || !cooked[1].equals("IfaceClass")) {
+                        throw new IllegalStateException(
+                                String.format("Invalid event from daemon (%s)", raw));
+                    }
+                    boolean isActive = cooked[2].equals("active");
+                    notifyInterfaceClassActivity(cooked[3], isActive);
+                    return true;
+                    // break;
             default: break;
             }
             return false;