Collect historical network stats.

Periodically records delta network traffic into historical buckets to
support other services, such NetworkPolicyManager and Settings UI.

Introduces NetworkStatsHistory structure which contains sparse, uniform
buckets of data usage defined by timestamps.  Service periodically
polls NetworkStats and records changes into buckets.  It only persists
to disk when substantial changes have occured.  Current parameters
create 4 buckets each day, and persist for 90 days, resulting in about
8kB of data per network.

Only records stats for "well known" network interfaces that have been
claimed by Telephony or Wi-Fi subsystems.  Historical stats are also
keyed off identity (such as IMSI) to support SIM swapping.

Change-Id: Ia27d1289556a2bf9545fbc4f3b789425a01be53a

1 files changed, 18 insertions, 29 deletions

diff --git a/services/java/com/android/server/net/NetworkPolicyManagerService.java b/services/java/com/android/server/net/NetworkPolicyManagerService.java
index 1ae8284..17c7161 100644
--- a/services/java/com/android/server/net/NetworkPolicyManagerService.java
+++ b/services/java/com/android/server/net/NetworkPolicyManagerService.java
@@ -35,10 +35,10 @@ import android.content.IntentFilter;
 import android.net.ConnectivityManager;
 import android.net.INetworkPolicyListener;
 import android.net.INetworkPolicyManager;
+import android.net.INetworkStatsService;
 import android.os.IPowerManager;
 import android.os.RemoteCallbackList;
 import android.os.RemoteException;
-import android.util.Log;
 import android.util.Slog;
 import android.util.SparseArray;
 import android.util.SparseBooleanArray;
@@ -59,11 +59,12 @@ public class NetworkPolicyManagerService extends INetworkPolicyManager.Stub {
     private static final String TAG = "NetworkPolicy";
     private static final boolean LOGD = true;
 
-    private Context mContext;
-    private IActivityManager mActivityManager;
-    private IPowerManager mPowerManager;
+    private final Context mContext;
+    private final IActivityManager mActivityManager;
+    private final IPowerManager mPowerManager;
+    private final INetworkStatsService mNetworkStats;
 
-    private Object mRulesLock = new Object();
+    private final Object mRulesLock = new Object();
 
     private boolean mScreenOn;
 
@@ -80,21 +81,24 @@ public class NetworkPolicyManagerService extends INetworkPolicyManager.Stub {
     private final RemoteCallbackList<INetworkPolicyListener> mListeners = new RemoteCallbackList<
             INetworkPolicyListener>();
 
-    // TODO: periodically poll network stats and write to disk
     // TODO: save/restore policy information from disk
 
     // TODO: keep whitelist of system-critical services that should never have
     // rules enforced, such as system, phone, and radio UIDs.
 
-    public NetworkPolicyManagerService(
-            Context context, IActivityManager activityManager, IPowerManager powerManager) {
+    // TODO: keep record of billing cycle details, and limit rules
+    // TODO: keep map of interfaces-to-billing-relationship
+
+    public NetworkPolicyManagerService(Context context, IActivityManager activityManager,
+            IPowerManager powerManager, INetworkStatsService networkStats) {
         mContext = checkNotNull(context, "missing context");
         mActivityManager = checkNotNull(activityManager, "missing activityManager");
         mPowerManager = checkNotNull(powerManager, "missing powerManager");
+        mNetworkStats = checkNotNull(networkStats, "missing networkStats");
     }
 
     public void systemReady() {
-        // TODO: read current policy+stats from disk and generate NMS rules
+        // TODO: read current policy from disk
 
         updateScreenOn();
 
@@ -114,18 +118,13 @@ public class NetworkPolicyManagerService extends INetworkPolicyManager.Stub {
         screenFilter.addAction(Intent.ACTION_SCREEN_OFF);
         mContext.registerReceiver(mScreenReceiver, screenFilter);
 
-        final IntentFilter shutdownFilter = new IntentFilter();
-        shutdownFilter.addAction(Intent.ACTION_SHUTDOWN);
-        mContext.registerReceiver(mShutdownReceiver, shutdownFilter);
-
     }
 
     private IProcessObserver mProcessObserver = new IProcessObserver.Stub() {
         @Override
         public void onForegroundActivitiesChanged(int pid, int uid, boolean foregroundActivities) {
             // only someone like AMS should only be calling us
-            mContext.enforceCallingOrSelfPermission(
-                    MANAGE_APP_TOKENS, "requires MANAGE_APP_TOKENS permission");
+            mContext.enforceCallingOrSelfPermission(MANAGE_APP_TOKENS, TAG);
 
             synchronized (mRulesLock) {
                 // because a uid can have multiple pids running inside, we need to
@@ -145,8 +144,7 @@ public class NetworkPolicyManagerService extends INetworkPolicyManager.Stub {
         @Override
         public void onProcessDied(int pid, int uid) {
             // only someone like AMS should only be calling us
-            mContext.enforceCallingOrSelfPermission(
-                    MANAGE_APP_TOKENS, "requires MANAGE_APP_TOKENS permission");
+            mContext.enforceCallingOrSelfPermission(MANAGE_APP_TOKENS, TAG);
 
             synchronized (mRulesLock) {
                 // clear records and recompute, when they exist
@@ -170,19 +168,10 @@ public class NetworkPolicyManagerService extends INetworkPolicyManager.Stub {
         }
     };
 
-    private BroadcastReceiver mShutdownReceiver = new BroadcastReceiver() {
-        @Override
-        public void onReceive(Context context, Intent intent) {
-            // TODO: persist any pending stats during clean shutdown
-            Log.d(TAG, "persisting stats");
-        }
-    };
-
     @Override
     public void setUidPolicy(int uid, int policy) {
         // TODO: create permission for modifying data policy
-        mContext.enforceCallingOrSelfPermission(
-                UPDATE_DEVICE_STATS, "requires UPDATE_DEVICE_STATS permission");
+        mContext.enforceCallingOrSelfPermission(UPDATE_DEVICE_STATS, TAG);
 
         final int oldPolicy;
         synchronized (mRulesLock) {
@@ -228,7 +217,7 @@ public class NetworkPolicyManagerService extends INetworkPolicyManager.Stub {
 
     @Override
     protected void dump(FileDescriptor fd, PrintWriter fout, String[] args) {
-        mContext.enforceCallingOrSelfPermission(DUMP, "requires DUMP permission");
+        mContext.enforceCallingOrSelfPermission(DUMP, TAG);
 
         synchronized (mRulesLock) {
             fout.println("Policy status for known UIDs:");
@@ -366,7 +355,7 @@ public class NetworkPolicyManagerService extends INetworkPolicyManager.Stub {
         }
         return value;
     }
-    
+
     private static void collectKeys(SparseIntArray source, SparseBooleanArray target) {
         final int size = source.size();
         for (int i = 0; i < size; i++) {