/*
* Copyright (C) 2016 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;
import android.annotation.Nullable;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.ActivityInfo;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.net.Uri;
import android.os.Binder;
import android.os.Build;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.os.UserHandle;
import android.provider.MediaStore;
import android.system.ErrnoException;
import android.system.Os;
import android.system.OsConstants;
import android.system.StructStat;
import android.util.ArraySet;
import android.util.Slog;
import com.android.internal.app.ResolverActivity;
import com.android.internal.os.BackgroundThread;
import com.android.internal.util.DumpUtils;
import dalvik.system.DexFile;
import dalvik.system.VMRuntime;
import java.io.FileDescriptor;
import java.io.Closeable;
import java.io.InputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.EOFException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.zip.ZipFile;
import java.util.zip.ZipException;
import java.util.zip.ZipEntry;
/**
* <p>PinnerService pins important files for key processes in memory.</p>
* <p>Files to pin are specified in the config_defaultPinnerServiceFiles
* overlay.</p>
* <p>Pin the default camera application if specified in config_pinnerCameraApp.</p>
*/
public final class PinnerService extends SystemService {
private static final boolean DEBUG = false;
private static final String TAG = "PinnerService";
private static final int MAX_CAMERA_PIN_SIZE = 80 * (1 << 20); //80MB max
private static final String PIN_META_FILENAME = "pinlist.meta";
private static final int PAGE_SIZE = (int) Os.sysconf(OsConstants._SC_PAGESIZE);
private final Context mContext;
private final boolean mShouldPinCamera;
/* These lists protected by PinnerService monitor lock */
private final ArrayList<PinnedFile> mPinnedFiles = new ArrayList<PinnedFile>();
private final ArrayList<PinnedFile> mPinnedCameraFiles = new ArrayList<PinnedFile>();
private BinderService mBinderService;
private PinnerHandler mPinnerHandler = null;
private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
// If this user's camera app has been updated, update pinned files accordingly.
if (intent.getAction() == Intent.ACTION_PACKAGE_REPLACED) {
Uri packageUri = intent.getData();
String packageName = packageUri.getSchemeSpecificPart();
ArraySet<String> updatedPackages = new ArraySet<>();
updatedPackages.add(packageName);
update(updatedPackages);
}
}
};
public PinnerService(Context context) {
super(context);
mContext = context;
mShouldPinCamera = context.getResources().getBoolean(
com.android.internal.R.bool.config_pinnerCameraApp);
mPinnerHandler = new PinnerHandler(BackgroundThread.get().getLooper());
IntentFilter filter = new IntentFilter();
filter.addAction(Intent.ACTION_PACKAGE_REPLACED);
filter.addDataScheme("package");
mContext.registerReceiver(mBroadcastReceiver, filter);
}
@Override
public void onStart() {
if (DEBUG) {
Slog.i(TAG, "Starting PinnerService");
}
mBinderService = new BinderService();
publishBinderService("pinner", mBinderService);
publishLocalService(PinnerService.class, this);
mPinnerHandler.obtainMessage(PinnerHandler.PIN_ONSTART_MSG).sendToTarget();
mPinnerHandler.obtainMessage(PinnerHandler.PIN_CAMERA_MSG, UserHandle.USER_SYSTEM, 0)
.sendToTarget();
}
/**
* Pin camera on user switch.
* If more than one user is using the device
* each user may set a different preference for the camera app.
* Make sure that user's preference is pinned into memory.
*/
@Override
public void onSwitchUser(int userHandle) {
mPinnerHandler.obtainMessage(PinnerHandler.PIN_CAMERA_MSG, userHandle, 0).sendToTarget();
}
/**
* Update the currently pinned files.
* Specifically, this only updates camera pinning.
* The other files pinned in onStart will not need to be updated.
*/
public void update(ArraySet<String> updatedPackages) {
ApplicationInfo cameraInfo = getCameraInfo(UserHandle.USER_SYSTEM);
if (cameraInfo != null && updatedPackages.contains(cameraInfo.packageName)) {
Slog.i(TAG, "Updating pinned files.");
mPinnerHandler.obtainMessage(PinnerHandler.PIN_CAMERA_MSG, UserHandle.USER_SYSTEM, 0)
.sendToTarget();
}
}
/**
* Handler for on start pinning message
*/
private void handlePinOnStart() {
// Files to pin come from the overlay and can be specified per-device config
String[] filesToPin = mContext.getResources().getStringArray(
com.android.internal.R.array.config_defaultPinnerServiceFiles);
// Continue trying to pin each file even if we fail to pin some of them
for (String fileToPin : filesToPin) {
PinnedFile pf = pinFile(fileToPin,
Integer.MAX_VALUE,
/*attemptPinIntrospection=*/false);
if (pf == null) {
Slog.e(TAG, "Failed to pin file = " + fileToPin);
continue;
}
synchronized (this) {
mPinnedFiles.add(pf);
}
}
}
/**
* Handler for camera pinning message
*/
private void handlePinCamera(int userHandle) {
if (!mShouldPinCamera) return;
if (!pinCamera(userHandle)) {
if (DEBUG) {
Slog.v(TAG, "Failed to pin camera.");
}
}
}
private void unpinCameraApp() {
ArrayList<PinnedFile> pinnedCameraFiles;
synchronized (this) {
pinnedCameraFiles = new ArrayList<>(mPinnedCameraFiles);
mPinnedCameraFiles.clear();
}
for (PinnedFile pinnedFile : pinnedCameraFiles) {
pinnedFile.close();
}
}
private boolean isResolverActivity(ActivityInfo info) {
return ResolverActivity.class.getName().equals(info.name);
}
private ApplicationInfo getCameraInfo(int userHandle) {
// find the camera via an intent
// use INTENT_ACTION_STILL_IMAGE_CAMERA instead of _SECURE. On a
// device without a fbe enabled, the _SECURE intent will never get set.
Intent cameraIntent = new Intent(MediaStore.INTENT_ACTION_STILL_IMAGE_CAMERA);
PackageManager pm = mContext.getPackageManager();
ResolveInfo cameraResolveInfo = pm.resolveActivityAsUser(cameraIntent,
PackageManager.MATCH_DEFAULT_ONLY | PackageManager.MATCH_DIRECT_BOOT_AWARE
| PackageManager.MATCH_DIRECT_BOOT_UNAWARE,
userHandle);
if (cameraResolveInfo == null ) {
//this is not necessarily an error
if (DEBUG) {
Slog.v(TAG, "Unable to resolve camera intent");
}
return null;
}
if (isResolverActivity(cameraResolveInfo.activityInfo))
{
if (DEBUG) {
Slog.v(TAG, "cameraIntent returned resolverActivity");
}
return null;
}
return cameraResolveInfo.activityInfo.applicationInfo;
}
/**
* If the camera app is already pinned, unpin and repin it.
*/
private boolean pinCamera(int userHandle){
ApplicationInfo cameraInfo = getCameraInfo(userHandle);
if (cameraInfo == null) {
return false;
}
//unpin after checking that the camera intent has resolved
//this prevents us from thrashing when switching users with
//FBE enabled, because the intent won't resolve until the unlock
unpinCameraApp();
//pin APK
String camAPK = cameraInfo.sourceDir;
PinnedFile pf = pinFile(camAPK,
MAX_CAMERA_PIN_SIZE,
/*attemptPinIntrospection=*/true);
if (pf == null) {
Slog.e(TAG, "Failed to pin " + camAPK);
return false;
}
if (DEBUG) {
Slog.i(TAG, "Pinned " + pf.fileName);
}
synchronized (this) {
mPinnedCameraFiles.add(pf);
}
// determine the ABI from either ApplicationInfo or Build
String arch = "arm";
if (cameraInfo.primaryCpuAbi != null) {
if (VMRuntime.is64BitAbi(cameraInfo.primaryCpuAbi)) {
arch = arch + "64";
}
} else {
if (VMRuntime.is64BitAbi(Build.SUPPORTED_ABIS[0])) {
arch = arch + "64";
}
}
// get the path to the odex or oat file
String baseCodePath = cameraInfo.getBaseCodePath();
String[] files = null;
try {
files = DexFile.getDexFileOutputPaths(baseCodePath, arch);
} catch (IOException ioe) {}
if (files == null) {
return true;
}
//not pinning the oat/odex is not a fatal error
for (String file : files) {
pf = pinFile(file, MAX_CAMERA_PIN_SIZE, /*attemptPinIntrospection=*/false);
if (pf != null) {
synchronized (this) {
mPinnedCameraFiles.add(pf);
}
if (DEBUG) {
Slog.i(TAG, "Pinned " + pf.fileName);
}
}
}
return true;
}
/** mlock length bytes of fileToPin in memory
*
* If attemptPinIntrospection is true, then treat the file to pin as a zip file and
* look for a "pinlist.meta" file in the archive root directory. The structure of this
* file is a PINLIST_META as described below:
*
* <pre>
* PINLIST_META: PIN_RANGE*
* PIN_RANGE: PIN_START PIN_LENGTH
* PIN_START: big endian i32: offset in bytes of pin region from file start
* PIN_LENGTH: big endian i32: length of pin region in bytes
* </pre>
*
* (We use big endian because that's what DataInputStream is hardcoded to use.)
*
* If attemptPinIntrospection is false, then we use a single implicit PIN_RANGE of (0,
* maxBytesToPin); that is, we attempt to pin the first maxBytesToPin bytes of the file.
*
* After we open a file, we march through the list of pin ranges and attempt to pin
* each one, stopping after we've pinned maxBytesToPin bytes. (We may truncate the last
* pinned range to fit.) In this way, by choosing to emit certain PIN_RANGE pairs
* before others, file generators can express pins in priority order, making most
* effective use of the pinned-page quota.
*
* N.B. Each PIN_RANGE is clamped to the actual bounds of the file; all inputs have a
* meaningful interpretation. Also, a range locking a single byte of a page locks the
* whole page. Any truncated PIN_RANGE at EOF is ignored. Overlapping pinned entries
* are legal, but each pin of a byte counts toward the pin quota regardless of whether
* that byte has already been pinned, so the generator of PINLIST_META ought to ensure
* that ranges are non-overlapping.
*
* @param fileToPin Path to file to pin
* @param maxBytesToPin Maximum number of bytes to pin
* @param attemptPinIntrospection If true, try to open file as a
* zip in order to extract the
* @return Pinned memory resource owner thing or null on error
*/
private static PinnedFile pinFile(String fileToPin,
int maxBytesToPin,
boolean attemptPinIntrospection) {
ZipFile fileAsZip = null;
InputStream pinRangeStream = null;
try {
if (attemptPinIntrospection) {
fileAsZip = maybeOpenZip(fileToPin);
}
if (fileAsZip != null) {
pinRangeStream = maybeOpenPinMetaInZip(fileAsZip, fileToPin);
}
Slog.d(TAG, "pinRangeStream: " + pinRangeStream);
PinRangeSource pinRangeSource = (pinRangeStream != null)
? new PinRangeSourceStream(pinRangeStream)
: new PinRangeSourceStatic(0, Integer.MAX_VALUE /* will be clipped */);
return pinFileRanges(fileToPin, maxBytesToPin, pinRangeSource);
} finally {
safeClose(pinRangeStream);
safeClose(fileAsZip); // Also closes any streams we've opened
}
}
/**
* Attempt to open a file as a zip file. On any sort of corruption, log, swallow the
* error, and return null.
*/
private static ZipFile maybeOpenZip(String fileName) {
ZipFile zip = null;
try {
zip = new ZipFile(fileName);
} catch (IOException ex) {
Slog.w(TAG,
String.format(
"could not open \"%s\" as zip: pinning as blob",
fileName),
ex);
}
return zip;
}
/**
* Open a pin metadata file in the zip if one is present.
*
* @param zipFile Zip file to search
* @return Open input stream or null on any error
*/
private static InputStream maybeOpenPinMetaInZip(ZipFile zipFile, String fileName) {
ZipEntry pinMetaEntry = zipFile.getEntry(PIN_META_FILENAME);
InputStream pinMetaStream = null;
if (pinMetaEntry != null) {
try {
pinMetaStream = zipFile.getInputStream(pinMetaEntry);
} catch (IOException ex) {
Slog.w(TAG,
String.format("error reading pin metadata \"%s\": pinning as blob",
fileName),
ex);
}
}
return pinMetaStream;
}
private static abstract class PinRangeSource {
/** Retrive a range to pin.
*
* @param outPinRange Receives the pin region
* @return True if we filled in outPinRange or false if we're out of pin entries
*/
abstract boolean read(PinRange outPinRange);
}
private static final class PinRangeSourceStatic extends PinRangeSource {
private final int mPinStart;
private final int mPinLength;
private boolean mDone = false;
PinRangeSourceStatic(int pinStart, int pinLength) {
mPinStart = pinStart;
mPinLength = pinLength;
}
@Override
boolean read(PinRange outPinRange) {
outPinRange.start = mPinStart;
outPinRange.length = mPinLength;
boolean done = mDone;
mDone = true;
return !done;
}
}
private static final class PinRangeSourceStream extends PinRangeSource {
private final DataInputStream mStream;
private boolean mDone = false;
PinRangeSourceStream(InputStream stream) {
mStream = new DataInputStream(stream);
}
@Override
boolean read(PinRange outPinRange) {
if (!mDone) {
try {
outPinRange.start = mStream.readInt();
outPinRange.length = mStream.readInt();
} catch (IOException ex) {
mDone = true;
}
}
return !mDone;
}
}
/**
* Helper for pinFile.
*
* @param fileToPin Name of file to pin
* @param maxBytesToPin Maximum number of bytes to pin
* @param pinRangeSource Read PIN_RANGE entries from this stream to tell us what bytes
* to pin.
* @return PinnedFile or null on error
*/
private static PinnedFile pinFileRanges(
String fileToPin,
int maxBytesToPin,
PinRangeSource pinRangeSource)
{
FileDescriptor fd = new FileDescriptor();
long address = -1;
int mapSize = 0;
try {
int openFlags = (OsConstants.O_RDONLY |
OsConstants.O_CLOEXEC |
OsConstants.O_NOFOLLOW);
fd = Os.open(fileToPin, openFlags, 0);
mapSize = (int) Math.min(Os.fstat(fd).st_size, Integer.MAX_VALUE);
address = Os.mmap(0, mapSize,
OsConstants.PROT_READ,
OsConstants.MAP_SHARED,
fd, /*offset=*/0);
PinRange pinRange = new PinRange();
int bytesPinned = 0;
// We pin at page granularity, so make sure the limit is page-aligned
if (maxBytesToPin % PAGE_SIZE != 0) {
maxBytesToPin -= maxBytesToPin % PAGE_SIZE;
}
while (bytesPinned < maxBytesToPin && pinRangeSource.read(pinRange)) {
int pinStart = pinRange.start;
int pinLength = pinRange.length;
pinStart = clamp(0, pinStart, mapSize);
pinLength = clamp(0, pinLength, mapSize - pinStart);
pinLength = Math.min(maxBytesToPin - bytesPinned, pinLength);
// mlock doesn't require the region to be page-aligned, but we snap the
// lock region to page boundaries anyway so that we don't under-count
// locking a single byte of a page as a charge of one byte even though the
// OS will retain the whole page. Thanks to this adjustment, we slightly
// over-count the pin charge of back-to-back pins touching the same page,
// but better that than undercounting. Besides: nothing stops pin metafile
// creators from making the actual regions page-aligned.
pinLength += pinStart % PAGE_SIZE;
pinStart -= pinStart % PAGE_SIZE;
if (pinLength % PAGE_SIZE != 0) {
pinLength += PAGE_SIZE - pinLength % PAGE_SIZE;
}
pinLength = clamp(0, pinLength, maxBytesToPin - bytesPinned);
if (pinLength > 0) {
if (DEBUG) {
Slog.d(TAG,
String.format(
"pinning at %s %s bytes of %s",
pinStart, pinLength, fileToPin));
}
Os.mlock(address + pinStart, pinLength);
}
bytesPinned += pinLength;
}
PinnedFile pinnedFile = new PinnedFile(address, mapSize, fileToPin, bytesPinned);
address = -1; // Ownership transferred
return pinnedFile;
} catch (ErrnoException ex) {
Slog.e(TAG, "Could not pin file " + fileToPin, ex);
return null;
} finally {
safeClose(fd);
if (address >= 0) {
safeMunmap(address, mapSize);
}
}
}
private static int clamp(int min, int value, int max) {
return Math.max(min, Math.min(value, max));
}
private static void safeMunmap(long address, long mapSize) {
try {
Os.munmap(address, mapSize);
} catch (ErrnoException ex) {
Slog.w(TAG, "ignoring error in unmap", ex);
}
}
/**
* Close FD, swallowing irrelevant errors.
*/
private static void safeClose(@Nullable FileDescriptor fd) {
if (fd != null && fd.valid()) {
try {
Os.close(fd);
} catch (ErrnoException ex) {
// Swallow the exception: non-EBADF errors in close(2)
// indicate deferred paging write errors, which we
// don't care about here. The underlying file
// descriptor is always closed.
if (ex.errno == OsConstants.EBADF) {
throw new AssertionError(ex);
}
}
}
}
/**
* Close closeable thing, swallowing errors.
*/
private static void safeClose(@Nullable Closeable thing) {
if (thing != null) {
try {
thing.close();
} catch (IOException ex) {
Slog.w(TAG, "ignoring error closing resource: " + thing, ex);
}
}
}
private synchronized ArrayList<PinnedFile> snapshotPinnedFiles() {
int nrPinnedFiles = mPinnedFiles.size() + mPinnedCameraFiles.size();
ArrayList<PinnedFile> pinnedFiles = new ArrayList<>(nrPinnedFiles);
pinnedFiles.addAll(mPinnedFiles);
pinnedFiles.addAll(mPinnedCameraFiles);
return pinnedFiles;
}
private final class BinderService extends Binder {
@Override
protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
if (!DumpUtils.checkDumpPermission(mContext, TAG, pw)) return;
long totalSize = 0;
for (PinnedFile pinnedFile : snapshotPinnedFiles()) {
pw.format("%s %s\n", pinnedFile.fileName, pinnedFile.bytesPinned);
totalSize += pinnedFile.bytesPinned;
}
pw.format("Total size: %s\n", totalSize);
}
}
private static final class PinnedFile implements AutoCloseable {
private long mAddress;
final int mapSize;
final String fileName;
final int bytesPinned;
PinnedFile(long address, int mapSize, String fileName, int bytesPinned) {
mAddress = address;
this.mapSize = mapSize;
this.fileName = fileName;
this.bytesPinned = bytesPinned;
}
@Override
public void close() {
if (mAddress >= 0) {
safeMunmap(mAddress, mapSize);
mAddress = -1;
}
}
@Override
public void finalize() {
close();
}
}
final static class PinRange {
int start;
int length;
}
final class PinnerHandler extends Handler {
static final int PIN_CAMERA_MSG = 4000;
static final int PIN_ONSTART_MSG = 4001;
public PinnerHandler(Looper looper) {
super(looper, null, true);
}
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case PIN_CAMERA_MSG:
{
handlePinCamera(msg.arg1);
}
break;
case PIN_ONSTART_MSG:
{
handlePinOnStart();
}
break;
default:
super.handleMessage(msg);
}
}
}
}