1 /* 2 * Copyright (C) 2019 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.net; 18 19 import android.annotation.NonNull; 20 import android.os.ParcelFileDescriptor; 21 import android.os.RemoteException; 22 import android.util.Log; 23 24 import java.io.FileDescriptor; 25 import java.util.concurrent.Executor; 26 27 /** @hide */ 28 final class TcpSocketKeepalive extends SocketKeepalive { 29 30 TcpSocketKeepalive(@NonNull IConnectivityManager service, 31 @NonNull Network network, 32 @NonNull ParcelFileDescriptor pfd, 33 @NonNull Executor executor, 34 @NonNull Callback callback) { 35 super(service, network, pfd, executor, callback); 36 } 37 38 /** 39 * Starts keepalives. {@code mSocket} must be a connected TCP socket. 40 * 41 * - The application must not write to or read from the socket after calling this method, until 42 * onDataReceived, onStopped, or onError are called. If it does, the keepalive will fail 43 * with {@link #ERROR_SOCKET_NOT_IDLE}, or {@code #ERROR_INVALID_SOCKET} if the socket 44 * experienced an error (as in poll(2) returned POLLERR or POLLHUP); if this happens, the data 45 * received from the socket may be invalid, and the socket can't be recovered. 46 * - If the socket has data in the send or receive buffer, then this call will fail with 47 * {@link #ERROR_SOCKET_NOT_IDLE} and can be retried after the data has been processed. 48 * An app could ensure this by using an application-layer protocol to receive acknowledgement 49 * that indicates all data has been delivered to server, e.g. HTTP 200 OK. 50 * Then the app could go into keepalive mode after reading all remaining data within the 51 * acknowledgement. 52 */ 53 @Override 54 void startImpl(int intervalSec) { 55 mExecutor.execute(() -> { 56 try { 57 final FileDescriptor fd = mPfd.getFileDescriptor(); 58 mService.startTcpKeepalive(mNetwork, fd, intervalSec, mCallback); 59 } catch (RemoteException e) { 60 Log.e(TAG, "Error starting packet keepalive: ", e); 61 throw e.rethrowFromSystemServer(); 62 } 63 }); 64 } 65 66 @Override 67 void stopImpl() { 68 mExecutor.execute(() -> { 69 try { 70 if (mSlot != null) { 71 mService.stopKeepalive(mNetwork, mSlot); 72 } 73 } catch (RemoteException e) { 74 Log.e(TAG, "Error stopping packet keepalive: ", e); 75 throw e.rethrowFromSystemServer(); 76 } 77 }); 78 } 79 } 80
