src/com/android/mtp/MtpService.java - platform/packages/services/Mtp - Git at Google

 /*
  * Copyright (C) 2010 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 com.android.mtp;

 import android.app.ActivityManager;
 import android.app.Service;
 import android.content.Context;
 import android.content.Intent;
 import android.hardware.usb.IUsbManager;
 import android.hardware.usb.UsbManager;
 import android.mtp.MtpDatabase;
 import android.mtp.MtpServer;
 import android.os.Binder;
 import android.os.Build;
 import android.os.Environment;
 import android.os.IBinder;
 import android.os.ParcelFileDescriptor;
 import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.os.UserHandle;
 import android.os.storage.StorageEventListener;
 import android.os.storage.StorageManager;
 import android.os.storage.StorageVolume;
 import android.util.Log;

 import androidx.annotation.GuardedBy;
 import androidx.annotation.NonNull;

 import com.android.internal.util.Preconditions;

 import java.io.File;
 import java.io.FileDescriptor;
 import java.util.HashMap;

 /**
  * The singleton service backing instances of MtpServer that are started for the foreground user.
  * The service has the responsibility of retrieving user storage information and managing server
  * lifetime.
  */
 public class MtpService extends Service {
     private static final String TAG = "MtpService";
     private static final boolean LOGD = false;

     // We restrict PTP to these subdirectories
     private static final String[] PTP_DIRECTORIES = new String[] {
         Environment.DIRECTORY_DCIM,
         Environment.DIRECTORY_PICTURES,
     };

     private final StorageEventListener mStorageEventListener = new StorageEventListener() {
         @Override
         public void onStorageStateChanged(String path, String oldState, String newState) {
             synchronized (MtpService.this) {
                 Log.d(TAG, "onStorageStateChanged " + path + " " + oldState + " -> " + newState);
                 if (Environment.MEDIA_MOUNTED.equals(newState)) {
                     // Updating mVolumes variable because new storage could be inserted
                     mVolumes = StorageManager.getVolumeList(getUserId(), 0);
                     for (int i = 0; i < mVolumes.length; i++) {
                         StorageVolume volume = mVolumes[i];
                         if (volume.getPath().equals(path)) {
                             mVolumeMap.put(path, volume);
                             if (mUnlocked && (volume.isPrimary() || !mPtpMode)) {
                                 addStorage(volume);
                             }
                             break;
                         }
                     }
                 } else if (Environment.MEDIA_MOUNTED.equals(oldState)) {
                     if (mVolumeMap.containsKey(path)) {
                         removeStorage(mVolumeMap.remove(path));
                     }
                 }
             }
         }
     };

     /**
      * Static state of MtpServer. MtpServer opens FD for MTP driver internally and we cannot open
      * multiple MtpServer at the same time. The static field used to handle the case where MtpServer
      * lives beyond the lifetime of MtpService.
      *
      * Lock MtpService.this before locking MtpService.class if needed. Otherwise it goes to
      * deadlock.
      */
     @GuardedBy("MtpService.class")
     private static ServerHolder sServerHolder;

     private StorageManager mStorageManager;

     @GuardedBy("this")
     private boolean mUnlocked;
     @GuardedBy("this")
     private boolean mPtpMode;

     // A map of user volumes that are currently mounted.
     @GuardedBy("this")
     private HashMap<String, StorageVolume> mVolumeMap;

     // All user volumes in existence, in any state.
     @GuardedBy("this")
     private StorageVolume[] mVolumes;

     @Override
     public void onCreate() {
         mVolumes = StorageManager.getVolumeList(getUserId(), 0);
         mVolumeMap = new HashMap<>();

         mStorageManager = this.getSystemService(StorageManager.class);
         mStorageManager.registerListener(mStorageEventListener);
     }

     @Override
     public void onDestroy() {
         mStorageManager.unregisterListener(mStorageEventListener);
         synchronized (MtpService.class) {
             if (sServerHolder != null) {
                 sServerHolder.database.setServer(null);
             }
         }
     }

     @Override
     public synchronized int onStartCommand(Intent intent, int flags, int startId) {
         mUnlocked = intent.getBooleanExtra(UsbManager.USB_DATA_UNLOCKED, false);
         mPtpMode = intent.getBooleanExtra(UsbManager.USB_FUNCTION_PTP, false);

         for (StorageVolume v : mVolumes) {
             if (v.getState().equals(Environment.MEDIA_MOUNTED)) {
                 mVolumeMap.put(v.getPath(), v);
             }
         }
         String[] subdirs = null;
         if (mPtpMode) {
             Environment.UserEnvironment env = new Environment.UserEnvironment(getUserId());
             int count = PTP_DIRECTORIES.length;
             subdirs = new String[count];
             for (int i = 0; i < count; i++) {
                 File file = env.buildExternalStoragePublicDirs(PTP_DIRECTORIES[i])[0];
                 // make sure this directory exists
                 file.mkdirs();
                 subdirs[i] = file.getName();
             }
         }
         final StorageVolume primary = StorageManager.getPrimaryVolume(mVolumes);
         startServer(primary, subdirs);
         return START_REDELIVER_INTENT;
     }

     private synchronized void startServer(StorageVolume primary, String[] subdirs) {
         if (!(UserHandle.myUserId() == ActivityManager.getCurrentUser())) {
             return;
         }
         synchronized (MtpService.class) {
             if (sServerHolder != null) {
                 if (LOGD) {
                     Log.d(TAG, "Cannot launch second MTP server.");
                 }
                 // Previously executed MtpServer is still running. It will be terminated
                 // because MTP device FD will become invalid soon. Also MtpService will get new
                 // intent after that when UsbDeviceManager configures USB with new state.
                 return;
             }

             Log.d(TAG, "starting MTP server in " + (mPtpMode ? "PTP mode" : "MTP mode") +
                     " with storage " + primary.getPath() + (mUnlocked ? " unlocked" : "") + " as user " + UserHandle.myUserId());

             final MtpDatabase database = new MtpDatabase(this, subdirs);
             IUsbManager usbMgr = IUsbManager.Stub.asInterface(ServiceManager.getService(
                     Context.USB_SERVICE));
             ParcelFileDescriptor controlFd = null;
             try {
                 controlFd = usbMgr.getControlFd(
                         mPtpMode ? UsbManager.FUNCTION_PTP : UsbManager.FUNCTION_MTP);
             } catch (RemoteException e) {
                 Log.e(TAG, "Error communicating with UsbManager: " + e);
             }
             FileDescriptor fd = null;
             if (controlFd == null) {
                 Log.i(TAG, "Couldn't get control FD!");
             } else {
                 fd = controlFd.getFileDescriptor();
             }

             final MtpServer server =
                     new MtpServer(database, fd, mPtpMode,
                             new OnServerTerminated(), Build.MANUFACTURER,
                             Build.MODEL, "1.0");
             database.setServer(server);
             sServerHolder = new ServerHolder(server, database);

             // Add currently mounted and enabled storages to the server
             if (mUnlocked) {
                 for (StorageVolume v : mVolumeMap.values()) {
                     addStorage(v);
                 }
             }
             server.start();
         }
     }

     @Override
     public IBinder onBind(Intent intent) {
         return new Binder();
     }

     private void addStorage(StorageVolume volume) {
         Log.v(TAG, "Adding MTP storage:" + volume.getPath());
         synchronized (MtpService.class) {
             if (sServerHolder != null) {
                 sServerHolder.database.addStorage(volume);
             }
         }
     }

     private void removeStorage(StorageVolume volume) {
         synchronized (MtpService.class) {
             if (sServerHolder != null) {
                 sServerHolder.database.removeStorage(volume);
             }
         }
     }

     private static class ServerHolder {
         @NonNull final MtpServer server;
         @NonNull final MtpDatabase database;

         ServerHolder(@NonNull MtpServer server, @NonNull MtpDatabase database) {
             Preconditions.checkNotNull(server);
             Preconditions.checkNotNull(database);
             this.server = server;
             this.database = database;
         }

         void close() {
             this.database.setServer(null);
         }
     }

     private class OnServerTerminated implements Runnable {
         @Override
         public void run() {
             synchronized (MtpService.class) {
                 if (sServerHolder == null) {
                     Log.e(TAG, "sServerHolder is unexpectedly null.");
                     return;
                 }
                 sServerHolder.close();
                 sServerHolder = null;
             }
         }
     }
 }
	/*
	* Copyright (C) 2010 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 com.android.mtp;

	import android.app.ActivityManager;
	import android.app.Service;
	import android.content.Context;
	import android.content.Intent;
	import android.hardware.usb.IUsbManager;
	import android.hardware.usb.UsbManager;
	import android.mtp.MtpDatabase;
	import android.mtp.MtpServer;
	import android.os.Binder;
	import android.os.Build;
	import android.os.Environment;
	import android.os.IBinder;
	import android.os.ParcelFileDescriptor;
	import android.os.RemoteException;
	import android.os.ServiceManager;
	import android.os.UserHandle;
	import android.os.storage.StorageEventListener;
	import android.os.storage.StorageManager;
	import android.os.storage.StorageVolume;
	import android.util.Log;

	import androidx.annotation.GuardedBy;
	import androidx.annotation.NonNull;

	import com.android.internal.util.Preconditions;

	import java.io.File;
	import java.io.FileDescriptor;
	import java.util.HashMap;

	/**
	* The singleton service backing instances of MtpServer that are started for the foreground user.
	* The service has the responsibility of retrieving user storage information and managing server
	* lifetime.
	*/
	public class MtpService extends Service {
	private static final String TAG = "MtpService";
	private static final boolean LOGD = false;

	// We restrict PTP to these subdirectories
	private static final String[] PTP_DIRECTORIES = new String[] {
	Environment.DIRECTORY_DCIM,
	Environment.DIRECTORY_PICTURES,
	};

	private final StorageEventListener mStorageEventListener = new StorageEventListener() {
	@Override
	public void onStorageStateChanged(String path, String oldState, String newState) {
	synchronized (MtpService.this) {
	Log.d(TAG, "onStorageStateChanged " + path + " " + oldState + " -> " + newState);
	if (Environment.MEDIA_MOUNTED.equals(newState)) {
	// Updating mVolumes variable because new storage could be inserted
	mVolumes = StorageManager.getVolumeList(getUserId(), 0);
	for (int i = 0; i < mVolumes.length; i++) {
	StorageVolume volume = mVolumes[i];
	if (volume.getPath().equals(path)) {
	mVolumeMap.put(path, volume);
	if (mUnlocked && (volume.isPrimary() \|\| !mPtpMode)) {
	addStorage(volume);
	}
	break;
	}
	}
	} else if (Environment.MEDIA_MOUNTED.equals(oldState)) {
	if (mVolumeMap.containsKey(path)) {
	removeStorage(mVolumeMap.remove(path));
	}
	}
	}
	}
	};

	/**
	* Static state of MtpServer. MtpServer opens FD for MTP driver internally and we cannot open
	* multiple MtpServer at the same time. The static field used to handle the case where MtpServer
	* lives beyond the lifetime of MtpService.
	*
	* Lock MtpService.this before locking MtpService.class if needed. Otherwise it goes to
	* deadlock.
	*/
	@GuardedBy("MtpService.class")
	private static ServerHolder sServerHolder;

	private StorageManager mStorageManager;

	@GuardedBy("this")
	private boolean mUnlocked;
	@GuardedBy("this")
	private boolean mPtpMode;

	// A map of user volumes that are currently mounted.
	@GuardedBy("this")
	private HashMap<String, StorageVolume> mVolumeMap;

	// All user volumes in existence, in any state.
	@GuardedBy("this")
	private StorageVolume[] mVolumes;

	@Override
	public void onCreate() {
	mVolumes = StorageManager.getVolumeList(getUserId(), 0);
	mVolumeMap = new HashMap<>();

	mStorageManager = this.getSystemService(StorageManager.class);
	mStorageManager.registerListener(mStorageEventListener);
	}

	@Override
	public void onDestroy() {
	mStorageManager.unregisterListener(mStorageEventListener);
	synchronized (MtpService.class) {
	if (sServerHolder != null) {
	sServerHolder.database.setServer(null);
	}
	}
	}

	@Override
	public synchronized int onStartCommand(Intent intent, int flags, int startId) {
	mUnlocked = intent.getBooleanExtra(UsbManager.USB_DATA_UNLOCKED, false);
	mPtpMode = intent.getBooleanExtra(UsbManager.USB_FUNCTION_PTP, false);

	for (StorageVolume v : mVolumes) {
	if (v.getState().equals(Environment.MEDIA_MOUNTED)) {
	mVolumeMap.put(v.getPath(), v);
	}
	}
	String[] subdirs = null;
	if (mPtpMode) {
	Environment.UserEnvironment env = new Environment.UserEnvironment(getUserId());
	int count = PTP_DIRECTORIES.length;
	subdirs = new String[count];
	for (int i = 0; i < count; i++) {
	File file = env.buildExternalStoragePublicDirs(PTP_DIRECTORIES[i])[0];
	// make sure this directory exists
	file.mkdirs();
	subdirs[i] = file.getName();
	}
	}
	final StorageVolume primary = StorageManager.getPrimaryVolume(mVolumes);
	startServer(primary, subdirs);
	return START_REDELIVER_INTENT;
	}

	private synchronized void startServer(StorageVolume primary, String[] subdirs) {
	if (!(UserHandle.myUserId() == ActivityManager.getCurrentUser())) {
	return;
	}
	synchronized (MtpService.class) {
	if (sServerHolder != null) {
	if (LOGD) {
	Log.d(TAG, "Cannot launch second MTP server.");
	}
	// Previously executed MtpServer is still running. It will be terminated
	// because MTP device FD will become invalid soon. Also MtpService will get new
	// intent after that when UsbDeviceManager configures USB with new state.
	return;
	}

	Log.d(TAG, "starting MTP server in " + (mPtpMode ? "PTP mode" : "MTP mode") +
	" with storage " + primary.getPath() + (mUnlocked ? " unlocked" : "") + " as user " + UserHandle.myUserId());

	final MtpDatabase database = new MtpDatabase(this, subdirs);
	IUsbManager usbMgr = IUsbManager.Stub.asInterface(ServiceManager.getService(
	Context.USB_SERVICE));
	ParcelFileDescriptor controlFd = null;
	try {
	controlFd = usbMgr.getControlFd(
	mPtpMode ? UsbManager.FUNCTION_PTP : UsbManager.FUNCTION_MTP);
	} catch (RemoteException e) {
	Log.e(TAG, "Error communicating with UsbManager: " + e);
	}
	FileDescriptor fd = null;
	if (controlFd == null) {
	Log.i(TAG, "Couldn't get control FD!");
	} else {
	fd = controlFd.getFileDescriptor();
	}

	final MtpServer server =
	new MtpServer(database, fd, mPtpMode,
	new OnServerTerminated(), Build.MANUFACTURER,
	Build.MODEL, "1.0");
	database.setServer(server);
	sServerHolder = new ServerHolder(server, database);

	// Add currently mounted and enabled storages to the server
	if (mUnlocked) {
	for (StorageVolume v : mVolumeMap.values()) {
	addStorage(v);
	}
	}
	server.start();
	}
	}

	@Override
	public IBinder onBind(Intent intent) {
	return new Binder();
	}

	private void addStorage(StorageVolume volume) {
	Log.v(TAG, "Adding MTP storage:" + volume.getPath());
	synchronized (MtpService.class) {
	if (sServerHolder != null) {
	sServerHolder.database.addStorage(volume);
	}
	}
	}

	private void removeStorage(StorageVolume volume) {
	synchronized (MtpService.class) {
	if (sServerHolder != null) {
	sServerHolder.database.removeStorage(volume);
	}
	}
	}

	private static class ServerHolder {
	@NonNull final MtpServer server;
	@NonNull final MtpDatabase database;

	ServerHolder(@NonNull MtpServer server, @NonNull MtpDatabase database) {
	Preconditions.checkNotNull(server);
	Preconditions.checkNotNull(database);
	this.server = server;
	this.database = database;
	}

	void close() {
	this.database.setServer(null);
	}
	}

	private class OnServerTerminated implements Runnable {
	@Override
	public void run() {
	synchronized (MtpService.class) {
	if (sServerHolder == null) {
	Log.e(TAG, "sServerHolder is unexpectedly null.");
	return;
	}
	sServerHolder.close();
	sServerHolder = null;
	}
	}
	}
	}