Return NetworkStats bundle from NM service.

Introduce NetworkStats which is a collection of network statistics,
which should match the structure communicated by kernel module through
netd.  Will introduce tags and fg/bg stats later.  Kept entirely in a
flat data structure to optimize parcel speed.

Initial pass at returning NetworkStats from NetworkManagementService,
both summary and details.  Will eventually pull data from kernel module
over netd connection.

Change-Id: I92d9f61678ec8c22e2ce26775fb035a0cf32413f

3 files changed, 106 insertions, 10 deletions

diff --git a/services/java/com/android/server/NetworkManagementService.java b/services/java/com/android/server/NetworkManagementService.java
index 44f5df2..d931350 100644
--- a/services/java/com/android/server/NetworkManagementService.java
+++ b/services/java/com/android/server/NetworkManagementService.java
@@ -23,6 +23,7 @@ import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.res.Resources;
 import android.content.pm.PackageManager;
+import android.net.NetworkStats;
 import android.net.Uri;
 import android.net.InterfaceConfiguration;
 import android.net.INetworkManagementEventObserver;
@@ -32,6 +33,8 @@ import android.net.wifi.WifiConfiguration;
 import android.net.wifi.WifiConfiguration.KeyMgmt;
 import android.os.INetworkManagementService;
 import android.os.Handler;
+import android.os.RemoteException;
+import android.os.SystemClock;
 import android.os.SystemProperties;
 import android.text.TextUtils;
 import android.util.Log;
@@ -44,13 +47,21 @@ import android.content.ContentResolver;
 import android.database.ContentObserver;
 
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.FileReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.RandomAccessFile;
+import java.io.Reader;
 import java.lang.IllegalStateException;
 
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.util.concurrent.CountDownLatch;
 
+import libcore.io.IoUtils;
+
 /**
  * @hide
  */
@@ -716,12 +727,47 @@ class NetworkManagementService extends INetworkManagementService.Stub {
         return -1;
     }
 
-    public long getInterfaceRxCounter(String iface) {
-        return getInterfaceCounter(iface, true);
+    /** {@inheritDoc} */
+    public NetworkStats getNetworkStatsSummary() {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.ACCESS_NETWORK_STATE, "NetworkManagementService");
+
+        final String[] ifaces = listInterfaces();
+        final NetworkStats.Builder stats = new NetworkStats.Builder(
+                SystemClock.elapsedRealtime(), ifaces.length);
+
+        for (String iface : ifaces) {
+            final long rx = getInterfaceCounter(iface, true);
+            final long tx = getInterfaceCounter(iface, false);
+            stats.addEntry(iface, NetworkStats.UID_ALL, rx, tx);
+        }
+
+        return stats.build();
     }
 
-    public long getInterfaceTxCounter(String iface) {
-        return getInterfaceCounter(iface, false);
+    /** {@inheritDoc} */
+    public NetworkStats getNetworkStatsDetail() {
+        mContext.enforceCallingOrSelfPermission(
+                android.Manifest.permission.ACCESS_NETWORK_STATE, "NetworkManagementService");
+
+        final File procPath = new File("/proc/uid_stat");
+        final String[] knownUids = procPath.list();
+        final NetworkStats.Builder stats = new NetworkStats.Builder(
+                SystemClock.elapsedRealtime(), knownUids.length);
+
+        // TODO: kernel module will provide interface-level stats in future
+        // TODO: migrate these stats to come across netd in bulk, instead of all
+        // these individual file reads.
+        for (String uid : knownUids) {
+            final File uidPath = new File(procPath, uid);
+            final int rx = readSingleIntFromFile(new File(uidPath, "tcp_rcv"));
+            final int tx = readSingleIntFromFile(new File(uidPath, "tcp_snd"));
+
+            final int uidInt = Integer.parseInt(uid);
+            stats.addEntry(NetworkStats.IFACE_ALL, uidInt, rx, tx);
+        }
+
+        return stats.build();
     }
 
     public void setInterfaceThrottle(String iface, int rxKbps, int txKbps) {
@@ -782,4 +828,24 @@ class NetworkManagementService extends INetworkManagementService.Stub {
     public int getInterfaceTxThrottle(String iface) {
         return getInterfaceThrottle(iface, false);
     }
+
+    /**
+     * Utility method to read a single plain-text {@link Integer} from the given
+     * {@link File}, usually from a {@code /proc/} filesystem.
+     */
+    private static int readSingleIntFromFile(File file) {
+        RandomAccessFile f = null;
+        try {
+            f = new RandomAccessFile(file, "r");
+            byte[] buffer = new byte[(int) f.length()];
+            f.readFully(buffer);
+            return Integer.parseInt(new String(buffer).trim());
+        } catch (NumberFormatException e) {
+            return -1;
+        } catch (IOException e) {
+            return -1;
+        } finally {
+            IoUtils.closeQuietly(f);
+        }
+    }
 }
diff --git a/services/java/com/android/server/ThrottleService.java b/services/java/com/android/server/ThrottleService.java
index 02332b7..510ff62 100644
--- a/services/java/com/android/server/ThrottleService.java
+++ b/services/java/com/android/server/ThrottleService.java
@@ -33,6 +33,7 @@ import android.content.res.Resources;
 import android.database.ContentObserver;
 import android.net.INetworkManagementEventObserver;
 import android.net.IThrottleManager;
+import android.net.NetworkStats;
 import android.net.ThrottleManager;
 import android.os.Binder;
 import android.os.Environment;
@@ -531,8 +532,17 @@ public class ThrottleService extends IThrottleManager.Stub {
             long incRead = 0;
             long incWrite = 0;
             try {
-                incRead = mNMService.getInterfaceRxCounter(mIface) - mLastRead;
-                incWrite = mNMService.getInterfaceTxCounter(mIface) - mLastWrite;
+                final NetworkStats stats = mNMService.getNetworkStatsSummary();
+                final int index = stats.findIndex(mIface, NetworkStats.UID_ALL);
+
+                if (index != -1) {
+                    incRead = stats.rx[index] - mLastRead;
+                    incWrite = stats.tx[index] - mLastWrite;
+                } else {
+                    // missing iface, assume stats are 0
+                    Slog.w(TAG, "unable to find stats for iface " + mIface);
+                }
+
                 // handle iface resets - on some device the 3g iface comes and goes and gets
                 // totals reset to 0.  Deal with it
                 if ((incRead < 0) || (incWrite < 0)) {
diff --git a/services/tests/servicestests/src/com/android/server/ThrottleServiceTest.java b/services/tests/servicestests/src/com/android/server/ThrottleServiceTest.java
index 6f55f46..f20d5e5 100644
--- a/services/tests/servicestests/src/com/android/server/ThrottleServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/ThrottleServiceTest.java
@@ -34,11 +34,17 @@ import android.content.ContextWrapper;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.net.INetworkManagementEventObserver;
+import android.net.NetworkStats;
 import android.net.ThrottleManager;
+import android.os.IBinder;
 import android.os.INetworkManagementService;
+import android.os.ServiceManager;
+import android.os.SystemClock;
 import android.provider.Settings;
 import android.test.AndroidTestCase;
+import android.test.suitebuilder.annotation.Suppress;
 import android.text.format.DateUtils;
+import android.util.Log;
 import android.util.TrustedTime;
 
 import java.util.Iterator;
@@ -222,6 +228,16 @@ public class ThrottleServiceTest extends AndroidTestCase {
         verify(mMockTime, mMockNMService);
     }
 
+    @Suppress
+    public void testReturnStats() throws Exception {
+        final IBinder b = ServiceManager.getService(Context.NETWORKMANAGEMENT_SERVICE);
+        final INetworkManagementService nmService = INetworkManagementService.Stub.asInterface(b);
+
+        // test is currently no-op, just exercises stats apis
+        Log.d(TAG, nmService.getNetworkStatsSummary().toString());
+        Log.d(TAG, nmService.getNetworkStatsDetail().toString());
+    }
+
     /**
      * Persist the given {@link ThrottleService} policy into {@link Settings}.
      */
@@ -272,12 +288,16 @@ public class ThrottleServiceTest extends AndroidTestCase {
     }
 
     /**
-     * Expect {@link NetworkManagementService#getInterfaceRxCounter} mock calls,
-     * responding with the given counter values.
+     * Expect {@link NetworkManagementService#getNetworkStatsSummary()} mock
+     * calls, responding with the given counter values.
      */
     public void expectGetInterfaceCounter(long rx, long tx) throws Exception {
-        expect(mMockNMService.getInterfaceRxCounter(isA(String.class))).andReturn(rx).atLeastOnce();
-        expect(mMockNMService.getInterfaceTxCounter(isA(String.class))).andReturn(tx).atLeastOnce();
+        // TODO: provide elapsedRealtime mock to match TimeAuthority
+        final NetworkStats.Builder stats = new NetworkStats.Builder(
+                SystemClock.elapsedRealtime(), 1);
+        stats.addEntry(TEST_IFACE, NetworkStats.UID_ALL, rx, tx);
+
+        expect(mMockNMService.getNetworkStatsSummary()).andReturn(stats.build()).atLeastOnce();
     }
 
     /**