| /* |
| * Copyright (C) 2019 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.net.shared; |
| |
| import static android.net.RouteInfo.RTN_UNICAST; |
| import static android.system.OsConstants.EBUSY; |
| |
| import android.net.INetd; |
| import android.net.IpPrefix; |
| import android.net.RouteInfo; |
| import android.net.TetherConfigParcel; |
| import android.os.RemoteException; |
| import android.os.ServiceSpecificException; |
| import android.os.SystemClock; |
| import android.util.Log; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * Implements common operations on INetd |
| * @hide |
| */ |
| public class NetdUtils { |
| private static final String TAG = NetdUtils.class.getSimpleName(); |
| |
| /** Start tethering. */ |
| public static void tetherStart(final INetd netd, final boolean usingLegacyDnsProxy, |
| final String[] dhcpRange) throws RemoteException, ServiceSpecificException { |
| final TetherConfigParcel config = new TetherConfigParcel(); |
| config.usingLegacyDnsProxy = usingLegacyDnsProxy; |
| config.dhcpRanges = dhcpRange; |
| netd.tetherStartWithConfiguration(config); |
| } |
| |
| /** Setup interface for tethering. */ |
| public static void tetherInterface(final INetd netd, final String iface, final IpPrefix dest) |
| throws RemoteException, ServiceSpecificException { |
| tetherInterface(netd, iface, dest, 20 /* maxAttempts */, 50 /* pollingIntervalMs */); |
| } |
| |
| /** Setup interface with configurable retries for tethering. */ |
| public static void tetherInterface(final INetd netd, final String iface, final IpPrefix dest, |
| int maxAttempts, int pollingIntervalMs) |
| throws RemoteException, ServiceSpecificException { |
| netd.tetherInterfaceAdd(iface); |
| networkAddInterface(netd, iface, maxAttempts, pollingIntervalMs); |
| List<RouteInfo> routes = new ArrayList<>(); |
| routes.add(new RouteInfo(dest, null, iface, RTN_UNICAST)); |
| RouteUtils.addRoutesToLocalNetwork(netd, iface, routes); |
| } |
| |
| /** |
| * Retry Netd#networkAddInterface for EBUSY error code. |
| * If the same interface (e.g., wlan0) is in client mode and then switches to tethered mode. |
| * There can be a race where puts the interface into the local network but interface is still |
| * in use in netd because the ConnectivityService thread hasn't processed the disconnect yet. |
| * See b/158269544 for detail. |
| */ |
| private static void networkAddInterface(final INetd netd, final String iface, |
| int maxAttempts, int pollingIntervalMs) |
| throws ServiceSpecificException, RemoteException { |
| for (int i = 1; i <= maxAttempts; i++) { |
| try { |
| netd.networkAddInterface(INetd.LOCAL_NET_ID, iface); |
| return; |
| } catch (ServiceSpecificException e) { |
| if (e.errorCode == EBUSY && i < maxAttempts) { |
| SystemClock.sleep(pollingIntervalMs); |
| continue; |
| } |
| |
| Log.e(TAG, "Retry Netd#networkAddInterface failure: " + e); |
| throw e; |
| } |
| } |
| } |
| |
| /** Reset interface for tethering. */ |
| public static void untetherInterface(final INetd netd, String iface) |
| throws RemoteException, ServiceSpecificException { |
| try { |
| netd.tetherInterfaceRemove(iface); |
| } finally { |
| netd.networkRemoveInterface(INetd.LOCAL_NET_ID, iface); |
| } |
| } |
| } |