FileBridge.java revision 9a1507aa10577badabcbe00396613a967302e456
178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey/* 278cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * Copyright (C) 2014 The Android Open Source Project 378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * 478cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * Licensed under the Apache License, Version 2.0 (the "License"); 578cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * you may not use this file except in compliance with the License. 678cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * You may obtain a copy of the License at 778cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * 878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * http://www.apache.org/licenses/LICENSE-2.0 978cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * 1078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * Unless required by applicable law or agreed to in writing, software 1178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * distributed under the License is distributed on an "AS IS" BASIS, 1278cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 1378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * See the License for the specific language governing permissions and 1478cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * limitations under the License. 1578cc340c2de873d6995c283b777476f7237d690fJeff Sharkey */ 1678cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 1778cc340c2de873d6995c283b777476f7237d690fJeff Sharkeypackage android.os; 1878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 1978cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport static android.system.OsConstants.AF_UNIX; 2078cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport static android.system.OsConstants.SOCK_STREAM; 2178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 2278cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport android.system.ErrnoException; 2378cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport android.system.Os; 2478cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport android.util.Log; 2578cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 2678cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport libcore.io.IoBridge; 2778cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport libcore.io.IoUtils; 2878cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport libcore.io.Memory; 2978cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport libcore.io.Streams; 3078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 3178cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport java.io.FileDescriptor; 3278cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport java.io.IOException; 3378cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport java.io.OutputStream; 3478cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport java.nio.ByteOrder; 3578cc340c2de873d6995c283b777476f7237d690fJeff Sharkeyimport java.util.Arrays; 3678cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 3778cc340c2de873d6995c283b777476f7237d690fJeff Sharkey/** 3878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * Simple bridge that allows file access across process boundaries without 3978cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * returning the underlying {@link FileDescriptor}. This is useful when the 4078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * server side needs to strongly assert that a client side is completely 4178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * hands-off. 4278cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * 4378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey * @hide 4478cc340c2de873d6995c283b777476f7237d690fJeff Sharkey */ 4578cc340c2de873d6995c283b777476f7237d690fJeff Sharkeypublic class FileBridge extends Thread { 4678cc340c2de873d6995c283b777476f7237d690fJeff Sharkey private static final String TAG = "FileBridge"; 4778cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 4878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey // TODO: consider extending to support bidirectional IO 4978cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 5078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey private static final int MSG_LENGTH = 8; 5178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 5278cc340c2de873d6995c283b777476f7237d690fJeff Sharkey /** CMD_WRITE [len] [data] */ 5378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey private static final int CMD_WRITE = 1; 5478cc340c2de873d6995c283b777476f7237d690fJeff Sharkey /** CMD_FSYNC */ 5578cc340c2de873d6995c283b777476f7237d690fJeff Sharkey private static final int CMD_FSYNC = 2; 56ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey /** CMD_CLOSE */ 57ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey private static final int CMD_CLOSE = 3; 5878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 5978cc340c2de873d6995c283b777476f7237d690fJeff Sharkey private FileDescriptor mTarget; 6078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 6178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey private final FileDescriptor mServer = new FileDescriptor(); 6278cc340c2de873d6995c283b777476f7237d690fJeff Sharkey private final FileDescriptor mClient = new FileDescriptor(); 6378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 6478cc340c2de873d6995c283b777476f7237d690fJeff Sharkey private volatile boolean mClosed; 6578cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 6678cc340c2de873d6995c283b777476f7237d690fJeff Sharkey public FileBridge() { 6778cc340c2de873d6995c283b777476f7237d690fJeff Sharkey try { 6878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey Os.socketpair(AF_UNIX, SOCK_STREAM, 0, mServer, mClient); 6978cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } catch (ErrnoException e) { 7078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey throw new RuntimeException("Failed to create bridge"); 7178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 7278cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 7378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 7478cc340c2de873d6995c283b777476f7237d690fJeff Sharkey public boolean isClosed() { 7578cc340c2de873d6995c283b777476f7237d690fJeff Sharkey return mClosed; 7678cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 7778cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 7878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey public void setTargetFile(FileDescriptor target) { 7978cc340c2de873d6995c283b777476f7237d690fJeff Sharkey mTarget = target; 8078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 8178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 8278cc340c2de873d6995c283b777476f7237d690fJeff Sharkey public FileDescriptor getClientSocket() { 8378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey return mClient; 8478cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 8578cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 8678cc340c2de873d6995c283b777476f7237d690fJeff Sharkey @Override 8778cc340c2de873d6995c283b777476f7237d690fJeff Sharkey public void run() { 8878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey final byte[] temp = new byte[8192]; 8978cc340c2de873d6995c283b777476f7237d690fJeff Sharkey try { 9078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey while (IoBridge.read(mServer, temp, 0, MSG_LENGTH) == MSG_LENGTH) { 9178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey final int cmd = Memory.peekInt(temp, 0, ByteOrder.BIG_ENDIAN); 9278cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 9378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey if (cmd == CMD_WRITE) { 9478cc340c2de873d6995c283b777476f7237d690fJeff Sharkey // Shuttle data into local file 9578cc340c2de873d6995c283b777476f7237d690fJeff Sharkey int len = Memory.peekInt(temp, 4, ByteOrder.BIG_ENDIAN); 9678cc340c2de873d6995c283b777476f7237d690fJeff Sharkey while (len > 0) { 9778cc340c2de873d6995c283b777476f7237d690fJeff Sharkey int n = IoBridge.read(mServer, temp, 0, Math.min(temp.length, len)); 985f1ed727e27cc00267539974372f062104052f56Jeff Sharkey if (n == -1) { 995f1ed727e27cc00267539974372f062104052f56Jeff Sharkey throw new IOException( 1005f1ed727e27cc00267539974372f062104052f56Jeff Sharkey "Unexpected EOF; still expected " + len + " bytes"); 1015f1ed727e27cc00267539974372f062104052f56Jeff Sharkey } 10278cc340c2de873d6995c283b777476f7237d690fJeff Sharkey IoBridge.write(mTarget, temp, 0, n); 10378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey len -= n; 10478cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 10578cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 10678cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } else if (cmd == CMD_FSYNC) { 10778cc340c2de873d6995c283b777476f7237d690fJeff Sharkey // Sync and echo back to confirm 10878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey Os.fsync(mTarget); 10978cc340c2de873d6995c283b777476f7237d690fJeff Sharkey IoBridge.write(mServer, temp, 0, MSG_LENGTH); 110ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey 111ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey } else if (cmd == CMD_CLOSE) { 112ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey // Close and echo back to confirm 113ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey Os.fsync(mTarget); 114ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey Os.close(mTarget); 115ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey mClosed = true; 116ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey IoBridge.write(mServer, temp, 0, MSG_LENGTH); 117ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey break; 11878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 11978cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 12078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 12178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } catch (ErrnoException e) { 122d3ca9917003a5e0650b559d58cf1eacf3b52bf34Jeff Sharkey Log.wtf(TAG, "Failed during bridge", e); 12378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } catch (IOException e) { 124d3ca9917003a5e0650b559d58cf1eacf3b52bf34Jeff Sharkey Log.wtf(TAG, "Failed during bridge", e); 12578cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } finally { 12678cc340c2de873d6995c283b777476f7237d690fJeff Sharkey IoUtils.closeQuietly(mTarget); 12778cc340c2de873d6995c283b777476f7237d690fJeff Sharkey IoUtils.closeQuietly(mServer); 12878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey IoUtils.closeQuietly(mClient); 12978cc340c2de873d6995c283b777476f7237d690fJeff Sharkey mClosed = true; 13078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 13178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 13278cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 13378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey public static class FileBridgeOutputStream extends OutputStream { 1349a1507aa10577badabcbe00396613a967302e456Jeff Sharkey private final ParcelFileDescriptor mClientPfd; 13578cc340c2de873d6995c283b777476f7237d690fJeff Sharkey private final FileDescriptor mClient; 13678cc340c2de873d6995c283b777476f7237d690fJeff Sharkey private final byte[] mTemp = new byte[MSG_LENGTH]; 13778cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 1389a1507aa10577badabcbe00396613a967302e456Jeff Sharkey public FileBridgeOutputStream(ParcelFileDescriptor clientPfd) { 1399a1507aa10577badabcbe00396613a967302e456Jeff Sharkey mClientPfd = clientPfd; 1409a1507aa10577badabcbe00396613a967302e456Jeff Sharkey mClient = clientPfd.getFileDescriptor(); 14178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 14278cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 14378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey @Override 14478cc340c2de873d6995c283b777476f7237d690fJeff Sharkey public void close() throws IOException { 145ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey try { 146ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey writeCommandAndBlock(CMD_CLOSE, "close()"); 147ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey } finally { 148ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey IoBridge.closeAndSignalBlockedThreads(mClient); 149ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey } 15078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 15178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 152a10311434778ea1be1621c2251c0c8c2966f337bJeff Sharkey public void fsync() throws IOException { 153ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey writeCommandAndBlock(CMD_FSYNC, "fsync()"); 154ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey } 155ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey 156ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey private void writeCommandAndBlock(int cmd, String cmdString) throws IOException { 157ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey Memory.pokeInt(mTemp, 0, cmd, ByteOrder.BIG_ENDIAN); 15878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey IoBridge.write(mClient, mTemp, 0, MSG_LENGTH); 15978cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 16078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey // Wait for server to ack 16178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey if (IoBridge.read(mClient, mTemp, 0, MSG_LENGTH) == MSG_LENGTH) { 162ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey if (Memory.peekInt(mTemp, 0, ByteOrder.BIG_ENDIAN) == cmd) { 16378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey return; 16478cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 16578cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 16678cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 167ec55ef0934b8e0d1bb705434947de817f7be57f1Jeff Sharkey throw new IOException("Failed to execute " + cmdString + " across bridge"); 16878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 16978cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 17078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey @Override 17178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey public void write(byte[] buffer, int byteOffset, int byteCount) throws IOException { 17278cc340c2de873d6995c283b777476f7237d690fJeff Sharkey Arrays.checkOffsetAndCount(buffer.length, byteOffset, byteCount); 17378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey Memory.pokeInt(mTemp, 0, CMD_WRITE, ByteOrder.BIG_ENDIAN); 17478cc340c2de873d6995c283b777476f7237d690fJeff Sharkey Memory.pokeInt(mTemp, 4, byteCount, ByteOrder.BIG_ENDIAN); 17578cc340c2de873d6995c283b777476f7237d690fJeff Sharkey IoBridge.write(mClient, mTemp, 0, MSG_LENGTH); 17678cc340c2de873d6995c283b777476f7237d690fJeff Sharkey IoBridge.write(mClient, buffer, byteOffset, byteCount); 17778cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 17878cc340c2de873d6995c283b777476f7237d690fJeff Sharkey 17978cc340c2de873d6995c283b777476f7237d690fJeff Sharkey @Override 18078cc340c2de873d6995c283b777476f7237d690fJeff Sharkey public void write(int oneByte) throws IOException { 18178cc340c2de873d6995c283b777476f7237d690fJeff Sharkey Streams.writeSingleByte(this, oneByte); 18278cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 18378cc340c2de873d6995c283b777476f7237d690fJeff Sharkey } 18478cc340c2de873d6995c283b777476f7237d690fJeff Sharkey} 185