DO NOT MERGE - Merge pie-platform-release (PPRL.181205.001) into master

Bug: 120502534
Change-Id: Idc8bfb6d97a869b76cfb87ca1a494201baf9e8bd

core/java/android/net/TrafficStats.java

@@ -333,6 +333,14 @@ public class TrafficStats {
 
     /**
      * Remove any statistics parameters from the given {@link Socket}.
+     * <p>
+     * In Android 8.1 (API level 27) and lower, a socket is automatically
+     * untagged when it's sent to another process using binder IPC with a
+     * {@code ParcelFileDescriptor} container. In Android 9.0 (API level 28)
+     * and higher, the socket tag is kept when the socket is sent to another
+     * process using binder IPC. You can mimic the previous behavior by
+     * calling {@code untagSocket()} before sending the socket to another
+     * process.
      */
     public static void untagSocket(Socket socket) throws SocketException {
         SocketTagger.get().untag(socket);

services/core/java/com/android/server/net/NetworkStatsService.java

@@ -955,8 +955,14 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
 
     @Override
     public long getIfaceStats(String iface, int type) {
+        // eBPF code doesn't provide per-interface TCP counters. Use xt_qtaguid for now.
+        // TODO: delete getMobileTcp(Rx|Tx)Packets entirely. See b/110443385 .
+        if (type == TYPE_TCP_TX_PACKETS || type == TYPE_TCP_RX_PACKETS) {
+            return nativeGetIfaceStat(iface, type, false);
+        } else {
             return nativeGetIfaceStat(iface, type, checkBpfStatsEnable());
         }
+    }
 
     @Override
     public long getTotalStats(int type) {