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/*
* 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.server.usb;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.hardware.usb.IUsbManager;
import android.hardware.usb.UsbAccessory;
import android.hardware.usb.UsbManager;
import android.net.Uri;
import android.os.Binder;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.Parcelable;
import android.os.ParcelFileDescriptor;
import android.os.UEventObserver;
import android.provider.Settings;
import android.util.Log;
import android.util.Slog;
import java.io.File;
import java.io.FileDescriptor;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
/**
* UsbService monitors for changes to USB state.
* This includes code for both USB host support (where the android device is the host)
* as well as USB device support (android device is connected to a USB host).
* Accessory mode is a special case of USB device mode, where the android device is
* connected to a USB host that supports the android accessory protocol.
*/
public class UsbService extends IUsbManager.Stub {
private static final String TAG = UsbService.class.getSimpleName();
private static final boolean LOG = false;
private static final String USB_CONNECTED_MATCH =
"DEVPATH=/devices/virtual/switch/usb_connected";
private static final String USB_CONFIGURATION_MATCH =
"DEVPATH=/devices/virtual/switch/usb_configuration";
private static final String USB_FUNCTIONS_MATCH =
"DEVPATH=/devices/virtual/usb_composite/";
private static final String USB_CONNECTED_PATH =
"/sys/class/switch/usb_connected/state";
private static final String USB_CONFIGURATION_PATH =
"/sys/class/switch/usb_configuration/state";
private static final String USB_COMPOSITE_CLASS_PATH =
"/sys/class/usb_composite";
private static final int MSG_UPDATE_STATE = 0;
private static final int MSG_FUNCTION_ENABLED = 1;
private static final int MSG_FUNCTION_DISABLED = 2;
// Delay for debouncing USB disconnects.
// We often get rapid connect/disconnect events when enabling USB functions,
// which need debouncing.
private static final int UPDATE_DELAY = 1000;
// current connected and configuration state
private int mConnected;
private int mConfiguration;
// last broadcasted connected and configuration state
private int mLastConnected = -1;
private int mLastConfiguration = -1;
// lists of enabled and disabled USB functions (for USB device mode)
private final ArrayList<String> mEnabledFunctions = new ArrayList<String>();
private final ArrayList<String> mDisabledFunctions = new ArrayList<String>();
private boolean mSystemReady;
private UsbAccessory mCurrentAccessory;
// functions to restore after exiting accessory mode
private final ArrayList<String> mAccessoryRestoreFunctions = new ArrayList<String>();
private final Context mContext;
private final Object mLock = new Object();
private final UsbDeviceSettingsManager mDeviceManager;
private final boolean mHasUsbAccessory;
/*
* Handles USB function enable/disable events (device mode)
*/
private final void functionEnabledLocked(String function, boolean enabled) {
boolean enteringAccessoryMode =
(mHasUsbAccessory && enabled && UsbManager.USB_FUNCTION_ACCESSORY.equals(function));
if (enteringAccessoryMode) {
// keep a list of functions to reenable after exiting accessory mode
mAccessoryRestoreFunctions.clear();
int count = mEnabledFunctions.size();
for (int i = 0; i < count; i++) {
String f = mEnabledFunctions.get(i);
// RNDIS should not be restored and adb is handled automatically
if (!UsbManager.USB_FUNCTION_RNDIS.equals(f) &&
!UsbManager.USB_FUNCTION_ADB.equals(f) &&
!UsbManager.USB_FUNCTION_ACCESSORY.equals(f)) {
mAccessoryRestoreFunctions.add(f);
}
}
}
if (enabled) {
if (!mEnabledFunctions.contains(function)) {
mEnabledFunctions.add(function);
}
mDisabledFunctions.remove(function);
} else {
if (!mDisabledFunctions.contains(function)) {
mDisabledFunctions.add(function);
}
mEnabledFunctions.remove(function);
}
if (enteringAccessoryMode) {
String[] strings = nativeGetAccessoryStrings();
if (strings != null) {
mCurrentAccessory = new UsbAccessory(strings);
Log.d(TAG, "entering USB accessory mode: " + mCurrentAccessory);
mDeviceManager.accessoryAttached(mCurrentAccessory);
} else {
Log.e(TAG, "nativeGetAccessoryStrings failed");
}
}
}
/*
* Listens for uevent messages from the kernel to monitor the USB state (device mode)
*/
private final UEventObserver mUEventObserver = new UEventObserver() {
@Override
public void onUEvent(UEventObserver.UEvent event) {
if (Log.isLoggable(TAG, Log.VERBOSE)) {
Slog.v(TAG, "USB UEVENT: " + event.toString());
}
synchronized (mLock) {
String name = event.get("SWITCH_NAME");
String state = event.get("SWITCH_STATE");
if (name != null && state != null) {
try {
int intState = Integer.parseInt(state);
if ("usb_connected".equals(name)) {
mConnected = intState;
// trigger an Intent broadcast
if (mSystemReady) {
// debounce disconnects to avoid problems bringing up USB tethering
update(mConnected == 0);
}
} else if ("usb_configuration".equals(name)) {
mConfiguration = intState;
// trigger an Intent broadcast
if (mSystemReady) {
update(mConnected == 0);
}
}
} catch (NumberFormatException e) {
Slog.e(TAG, "Could not parse switch state from event " + event);
}
} else {
String function = event.get("FUNCTION");
String enabledStr = event.get("ENABLED");
if (function != null && enabledStr != null) {
// Note: we do not broadcast a change when a function is enabled or disabled.
// We just record the state change for the next broadcast.
int what = ("1".equals(enabledStr) ?
MSG_FUNCTION_ENABLED : MSG_FUNCTION_DISABLED);
Message msg = Message.obtain(mHandler, what);
msg.obj = function;
mHandler.sendMessage(msg);
}
}
}
}
};
public UsbService(Context context) {
mContext = context;
mDeviceManager = new UsbDeviceSettingsManager(context);
PackageManager pm = mContext.getPackageManager();
mHasUsbAccessory = pm.hasSystemFeature(PackageManager.FEATURE_USB_ACCESSORY);
init(); // set initial status
if (mConfiguration >= 0) {
mUEventObserver.startObserving(USB_CONNECTED_MATCH);
mUEventObserver.startObserving(USB_CONFIGURATION_MATCH);
mUEventObserver.startObserving(USB_FUNCTIONS_MATCH);
}
}
private final void init() {
char[] buffer = new char[1024];
// Read initial USB state (device mode)
mConfiguration = -1;
try {
FileReader file = new FileReader(USB_CONNECTED_PATH);
int len = file.read(buffer, 0, 1024);
file.close();
mConnected = Integer.valueOf((new String(buffer, 0, len)).trim());
file = new FileReader(USB_CONFIGURATION_PATH);
len = file.read(buffer, 0, 1024);
file.close();
mConfiguration = Integer.valueOf((new String(buffer, 0, len)).trim());
} catch (FileNotFoundException e) {
Slog.i(TAG, "This kernel does not have USB configuration switch support");
} catch (Exception e) {
Slog.e(TAG, "" , e);
}
if (mConfiguration < 0)
return;
// Read initial list of enabled and disabled functions (device mode)
try {
File[] files = new File(USB_COMPOSITE_CLASS_PATH).listFiles();
for (int i = 0; i < files.length; i++) {
File file = new File(files[i], "enable");
FileReader reader = new FileReader(file);
int len = reader.read(buffer, 0, 1024);
reader.close();
int value = Integer.valueOf((new String(buffer, 0, len)).trim());
String functionName = files[i].getName();
if (value == 1) {
mEnabledFunctions.add(functionName);
} else {
mDisabledFunctions.add(functionName);
}
}
} catch (FileNotFoundException e) {
Slog.w(TAG, "This kernel does not have USB composite class support");
} catch (Exception e) {
Slog.e(TAG, "" , e);
}
}
public void systemReady() {
synchronized (mLock) {
update(false);
mSystemReady = true;
}
}
/*
* Sends a message to update the USB connected and configured state (device mode).
* If delayed is true, then we add a small delay in sending the message to debounce
* the USB connection when enabling USB tethering.
*/
private final void update(boolean delayed) {
mHandler.removeMessages(MSG_UPDATE_STATE);
mHandler.sendEmptyMessageDelayed(MSG_UPDATE_STATE, delayed ? UPDATE_DELAY : 0);
}
/* returns the currently attached USB accessory (device mode) */
public UsbAccessory getCurrentAccessory() {
synchronized (mLock) {
mDeviceManager.checkPermission(mCurrentAccessory);
return mCurrentAccessory;
}
}
/* opens the currently attached USB accessory (device mode) */
public ParcelFileDescriptor openAccessory(UsbAccessory accessory) {
synchronized (mLock) {
if (mCurrentAccessory == null) {
throw new IllegalArgumentException("no accessory attached");
}
if (!mCurrentAccessory.equals(accessory)) {
Log.e(TAG, accessory.toString() + " does not match current accessory "
+ mCurrentAccessory);
throw new IllegalArgumentException("accessory not attached");
}
mDeviceManager.checkPermission(mCurrentAccessory);
return nativeOpenAccessory();
}
}
public void setAccessoryPackage(UsbAccessory accessory, String packageName) {
mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_USB, null);
mDeviceManager.setAccessoryPackage(accessory, packageName);
}
public void grantAccessoryPermission(UsbAccessory accessory, int uid) {
mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_USB, null);
mDeviceManager.grantAccessoryPermission(accessory, uid);
}
public boolean hasDefaults(String packageName, int uid) {
mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_USB, null);
return mDeviceManager.hasDefaults(packageName, uid);
}
public void clearDefaults(String packageName, int uid) {
mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_USB, null);
mDeviceManager.clearDefaults(packageName, uid);
}
/*
* This handler is for deferred handling of events related to device mode and accessories.
*/
private final Handler mHandler = new Handler() {
private void addEnabledFunctionsLocked(Intent intent) {
// include state of all USB functions in our extras
for (int i = 0; i < mEnabledFunctions.size(); i++) {
intent.putExtra(mEnabledFunctions.get(i), UsbManager.USB_FUNCTION_ENABLED);
}
for (int i = 0; i < mDisabledFunctions.size(); i++) {
intent.putExtra(mDisabledFunctions.get(i), UsbManager.USB_FUNCTION_DISABLED);
}
}
@Override
public void handleMessage(Message msg) {
synchronized (mLock) {
switch (msg.what) {
case MSG_UPDATE_STATE:
if (mConnected != mLastConnected || mConfiguration != mLastConfiguration) {
if (mConnected == 0 && mCurrentAccessory != null) {
// turn off accessory mode when we are disconnected
if (UsbManager.setFunctionEnabled(
UsbManager.USB_FUNCTION_ACCESSORY, false)) {
Log.d(TAG, "exited USB accessory mode");
// restore previously enabled functions
for (String function : mAccessoryRestoreFunctions) {
if (UsbManager.setFunctionEnabled(function, true)) {
Log.e(TAG, "could not reenable function " + function);
}
}
mAccessoryRestoreFunctions.clear();
mDeviceManager.accessoryDetached(mCurrentAccessory);
mCurrentAccessory = null;
// this will cause an immediate reset of the USB bus,
// so there is no point in sending the
// function disabled broadcast.
return;
} else {
Log.e(TAG, "could not disable USB_FUNCTION_ACCESSORY");
}
}
final ContentResolver cr = mContext.getContentResolver();
if (Settings.Secure.getInt(cr,
Settings.Secure.DEVICE_PROVISIONED, 0) == 0) {
Slog.i(TAG, "Device not provisioned, skipping USB broadcast");
return;
}
mLastConnected = mConnected;
mLastConfiguration = mConfiguration;
// send a sticky broadcast containing current USB state
Intent intent = new Intent(UsbManager.ACTION_USB_STATE);
intent.addFlags(Intent.FLAG_RECEIVER_REPLACE_PENDING);
intent.putExtra(UsbManager.USB_CONNECTED, mConnected != 0);
intent.putExtra(UsbManager.USB_CONFIGURATION, mConfiguration);
addEnabledFunctionsLocked(intent);
mContext.sendStickyBroadcast(intent);
}
break;
case MSG_FUNCTION_ENABLED:
case MSG_FUNCTION_DISABLED:
functionEnabledLocked((String)msg.obj, msg.what == MSG_FUNCTION_ENABLED);
break;
}
}
}
};
@Override
public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP)
!= PackageManager.PERMISSION_GRANTED) {
pw.println("Permission Denial: can't dump UsbManager from from pid="
+ Binder.getCallingPid()
+ ", uid=" + Binder.getCallingUid());
return;
}
synchronized (mLock) {
pw.println("USB Manager State:");
pw.println(" USB Device State:");
pw.print(" Enabled Functions: ");
for (int i = 0; i < mEnabledFunctions.size(); i++) {
pw.print(mEnabledFunctions.get(i) + " ");
}
pw.println("");
pw.print(" Disabled Functions: ");
for (int i = 0; i < mDisabledFunctions.size(); i++) {
pw.print(mDisabledFunctions.get(i) + " ");
}
pw.println("");
pw.println(" mConnected: " + mConnected + ", mConfiguration: " + mConfiguration);
pw.println(" mCurrentAccessory: " + mCurrentAccessory);
mDeviceManager.dump(fd, pw);
}
}
// accessory support
private native String[] nativeGetAccessoryStrings();
private native ParcelFileDescriptor nativeOpenAccessory();
}
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