Merge "Add blocking and retrying wrappers for INetd uses."

services/net/java/android/net/ip/IpManager.java

@@ -23,6 +23,7 @@ import android.content.Context;
 import android.net.apf.ApfCapabilities;
 import android.net.apf.ApfFilter;
 import android.net.DhcpResults;
+import android.net.INetd;
 import android.net.InterfaceConfiguration;
 import android.net.LinkAddress;
 import android.net.LinkProperties;
@@ -34,10 +35,12 @@ import android.net.dhcp.DhcpClient;
 import android.net.metrics.IpConnectivityLog;
 import android.net.metrics.IpManagerEvent;
 import android.net.util.MultinetworkPolicyTracker;
+import android.net.util.NetdService;
 import android.os.INetworkManagementService;
 import android.os.Message;
 import android.os.RemoteException;
 import android.os.ServiceManager;
+import android.os.ServiceSpecificException;
 import android.os.SystemClock;
 import android.text.TextUtils;
 import android.util.LocalLog;
@@ -1027,14 +1030,16 @@ public class IpManager extends StateMachine {
 
     private boolean startIPv6() {
         // Set privacy extensions.
+        final String PREFER_TEMPADDRS = "2";
         try {
-            mNwService.setInterfaceIpv6PrivacyExtensions(mInterfaceName, true);
+            NetdService.run((INetd netd) -> {
+                netd.setProcSysNet(
+                        INetd.IPV6, INetd.CONF, mInterfaceName, "use_tempaddr",
+                        PREFER_TEMPADDRS);
+            });
             mNwService.enableIpv6(mInterfaceName);
-        } catch (RemoteException re) {
-            logError("Unable to change interface settings: %s", re);
-            return false;
-        } catch (IllegalStateException ie) {
-            logError("Unable to change interface settings: %s", ie);
+        } catch (IllegalStateException|RemoteException|ServiceSpecificException e) {
+            logError("Unable to change interface settings: %s", e);
             return false;
         }
 

services/net/java/android/net/util/NetdService.java

@@ -17,7 +17,10 @@
 package android.net.util;
 
 import android.net.INetd;
+import android.os.RemoteException;
 import android.os.ServiceManager;
+import android.os.ServiceSpecificException;
+import android.os.SystemClock;
 import android.util.Log;
 
 
@@ -27,15 +30,24 @@ import android.util.Log;
 public class NetdService {
     private static final String TAG = NetdService.class.getSimpleName();
     private static final String NETD_SERVICE_NAME = "netd";
+    private static final long BASE_TIMEOUT_MS = 100;
+    private static final long MAX_TIMEOUT_MS = 1000;
+
 
     /**
+     * Return an INetd instance, or null if not available.
+     *
      * It is the caller's responsibility to check for a null return value
      * and to handle RemoteException errors from invocations on the returned
      * interface if, for example, netd dies and is restarted.
      *
+     * Returned instances of INetd should not be cached.
+     *
      * @return an INetd instance or null.
      */
     public static INetd getInstance() {
+        // NOTE: ServiceManager does no caching for the netd service,
+        // because netd is not one of the defined common services.
         final INetd netdInstance = INetd.Stub.asInterface(
                 ServiceManager.getService(NETD_SERVICE_NAME));
         if (netdInstance == null) {
@@ -43,4 +55,82 @@ public class NetdService {
         }
         return netdInstance;
     }
+
+    /**
+     * Blocks for a specified time until an INetd instance is available.
+     *
+     * It is the caller's responsibility to handle RemoteException errors
+     * from invocations on the returned interface if, for example, netd
+     * dies after this interface was returned.
+     *
+     * Returned instances of INetd should not be cached.
+     *
+     * Special values of maxTimeoutMs include: 0, meaning try to obtain an
+     * INetd instance only once, and -1 (or any value less than 0), meaning
+     * try to obtain an INetd instance indefinitely.
+     *
+     * @param maxTimeoutMs the maximum time to spend getting an INetd instance
+     * @return an INetd instance or null if no instance is available
+     * within |maxTimeoutMs| milliseconds.
+     */
+    public static INetd get(long maxTimeoutMs) {
+        if (maxTimeoutMs == 0) return getInstance();
+
+        final long stop = (maxTimeoutMs > 0)
+                ? SystemClock.elapsedRealtime() + maxTimeoutMs
+                : Long.MAX_VALUE;
+
+        long timeoutMs = 0;
+        while (true) {
+            final INetd netdInstance = getInstance();
+            if (netdInstance != null) {
+                return netdInstance;
+            }
+
+            final long remaining = stop - SystemClock.elapsedRealtime();
+            if (remaining <= 0) break;
+
+            // No netdInstance was received; sleep and retry.
+            timeoutMs = Math.min(timeoutMs + BASE_TIMEOUT_MS, MAX_TIMEOUT_MS);
+            timeoutMs = Math.min(timeoutMs, remaining);
+            try {
+                Thread.sleep(timeoutMs);
+            } catch (InterruptedException e) {}
+        }
+        return null;
+    }
+
+    /**
+     * Blocks until an INetd instance is available.
+     *
+     * It is the caller's responsibility to handle RemoteException errors
+     * from invocations on the returned interface if, for example, netd
+     * dies after this interface was returned.
+     *
+     * Returned instances of INetd should not be cached.
+     *
+     * @return an INetd instance.
+     */
+    public static INetd get() {
+        return get(-1);
+    }
+
+    public static interface NetdCommand {
+        void run(INetd netd) throws RemoteException;
+    }
+
+    /**
+     * Blocks until an INetd instance is availabe, and retries until either
+     * the command succeeds or a runtime exception is thrown.
+     */
+    public static void run(NetdCommand cmd) {
+        while (true) {
+            try {
+                cmd.run(get());
+                return;
+            } catch (RemoteException re) {
+                Log.e(TAG, "error communicating with netd: " + re);
+            }
+        }
+    }
 }