1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
|
/*
* Copyright (C) 2012 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.content.BroadcastReceiver;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.ServiceConnection;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.pm.ResolveInfo;
import android.content.pm.Signature;
import android.content.res.Resources;
import android.os.Handler;
import android.os.IBinder;
import android.os.UserHandle;
import android.util.Log;
import com.android.internal.content.PackageMonitor;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
/**
* Find the best Service, and bind to it.
* Handles run-time package changes.
*/
public class ServiceWatcher implements ServiceConnection {
private static final boolean D = false;
public static final String EXTRA_SERVICE_VERSION = "serviceVersion";
public static final String EXTRA_SERVICE_IS_MULTIUSER = "serviceIsMultiuser";
private final String mTag;
private final Context mContext;
private final PackageManager mPm;
private final List<HashSet<Signature>> mSignatureSets;
private final String mAction;
/**
* If mServicePackageName is not null, only this package will be searched for the service that
* implements mAction. When null, all packages in the system that matches one of the signature
* in mSignatureSets are searched.
*/
private final String mServicePackageName;
private final Runnable mNewServiceWork;
private final Handler mHandler;
private Object mLock = new Object();
// all fields below synchronized on mLock
private IBinder mBinder; // connected service
private String mPackageName; // current best package
private int mVersion = Integer.MIN_VALUE; // current best version
/**
* Whether the currently-connected service is multiuser-aware. This can change at run-time
* when switching from one version of a service to another.
*/
private boolean mIsMultiuser = false;
public static ArrayList<HashSet<Signature>> getSignatureSets(Context context,
List<String> initialPackageNames) {
PackageManager pm = context.getPackageManager();
ArrayList<HashSet<Signature>> sigSets = new ArrayList<HashSet<Signature>>();
for (int i = 0, size = initialPackageNames.size(); i < size; i++) {
String pkg = initialPackageNames.get(i);
try {
HashSet<Signature> set = new HashSet<Signature>();
Signature[] sigs = pm.getPackageInfo(pkg, PackageManager.GET_SIGNATURES).signatures;
set.addAll(Arrays.asList(sigs));
sigSets.add(set);
} catch (NameNotFoundException e) {
Log.w("ServiceWatcher", pkg + " not found");
}
}
return sigSets;
}
public ServiceWatcher(Context context, String logTag, String action,
int overlaySwitchResId, int defaultServicePackageNameResId,
int initialPackageNamesResId, Runnable newServiceWork,
Handler handler) {
mContext = context;
mTag = logTag;
mAction = action;
mPm = mContext.getPackageManager();
mNewServiceWork = newServiceWork;
mHandler = handler;
Resources resources = context.getResources();
// Whether to enable service overlay.
boolean enableOverlay = resources.getBoolean(overlaySwitchResId);
ArrayList<String> initialPackageNames = new ArrayList<String>();
if (enableOverlay) {
// A list of package names used to create the signatures.
String[] pkgs = resources.getStringArray(initialPackageNamesResId);
if (pkgs != null) initialPackageNames.addAll(Arrays.asList(pkgs));
mServicePackageName = null;
if (D) Log.d(mTag, "Overlay enabled, packages=" + Arrays.toString(pkgs));
} else {
// The default package name that is searched for service implementation when overlay is
// disabled.
String servicePackageName = resources.getString(defaultServicePackageNameResId);
if (servicePackageName != null) initialPackageNames.add(servicePackageName);
mServicePackageName = servicePackageName;
if (D) Log.d(mTag, "Overlay disabled, default package=" + servicePackageName);
}
mSignatureSets = getSignatureSets(context, initialPackageNames);
}
public boolean start() {
synchronized (mLock) {
if (!bindBestPackageLocked(mServicePackageName)) return false;
}
// listen for user change
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(Intent.ACTION_USER_SWITCHED);
mContext.registerReceiverAsUser(new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (Intent.ACTION_USER_SWITCHED.equals(action)) {
switchUser();
}
}
}, UserHandle.ALL, intentFilter, null, mHandler);
// listen for relevant package changes if service overlay is enabled.
if (mServicePackageName == null) {
mPackageMonitor.register(mContext, null, UserHandle.ALL, true);
}
return true;
}
/**
* Searches and binds to the best package, or do nothing
* if the best package is already bound.
* Only checks the named package, or checks all packages if it
* is null.
* Return true if a new package was found to bind to.
*/
private boolean bindBestPackageLocked(String justCheckThisPackage) {
Intent intent = new Intent(mAction);
if (justCheckThisPackage != null) {
intent.setPackage(justCheckThisPackage);
}
List<ResolveInfo> rInfos = mPm.queryIntentServicesAsUser(intent,
PackageManager.GET_META_DATA, UserHandle.USER_OWNER);
int bestVersion = Integer.MIN_VALUE;
String bestPackage = null;
boolean bestIsMultiuser = false;
if (rInfos != null) {
for (ResolveInfo rInfo : rInfos) {
String packageName = rInfo.serviceInfo.packageName;
// check signature
try {
PackageInfo pInfo;
pInfo = mPm.getPackageInfo(packageName, PackageManager.GET_SIGNATURES);
if (!isSignatureMatch(pInfo.signatures)) {
Log.w(mTag, packageName + " resolves service " + mAction
+ ", but has wrong signature, ignoring");
continue;
}
} catch (NameNotFoundException e) {
Log.wtf(mTag, e);
continue;
}
// check metadata
int version = Integer.MIN_VALUE;
boolean isMultiuser = false;
if (rInfo.serviceInfo.metaData != null) {
version = rInfo.serviceInfo.metaData.getInt(
EXTRA_SERVICE_VERSION, Integer.MIN_VALUE);
isMultiuser = rInfo.serviceInfo.metaData.getBoolean(EXTRA_SERVICE_IS_MULTIUSER);
}
if (version > mVersion) {
bestVersion = version;
bestPackage = packageName;
bestIsMultiuser = isMultiuser;
}
}
if (D) {
Log.d(mTag, String.format("bindBestPackage for %s : %s found %d, %s", mAction,
(justCheckThisPackage == null ? ""
: "(" + justCheckThisPackage + ") "), rInfos.size(),
(bestPackage == null ? "no new best package"
: "new best package: " + bestPackage)));
}
} else {
if (D) Log.d(mTag, "Unable to query intent services for action: " + mAction);
}
if (bestPackage != null) {
bindToPackageLocked(bestPackage, bestVersion, bestIsMultiuser);
return true;
}
return false;
}
private void unbindLocked() {
String pkg;
pkg = mPackageName;
mPackageName = null;
mVersion = Integer.MIN_VALUE;
mIsMultiuser = false;
if (pkg != null) {
if (D) Log.d(mTag, "unbinding " + pkg);
mContext.unbindService(this);
}
}
private void bindToPackageLocked(String packageName, int version, boolean isMultiuser) {
unbindLocked();
Intent intent = new Intent(mAction);
intent.setPackage(packageName);
mPackageName = packageName;
mVersion = version;
mIsMultiuser = isMultiuser;
if (D) Log.d(mTag, "binding " + packageName + " (version " + version + ") ("
+ (isMultiuser ? "multi" : "single") + "-user)");
mContext.bindServiceAsUser(intent, this, Context.BIND_AUTO_CREATE | Context.BIND_NOT_FOREGROUND
| Context.BIND_NOT_VISIBLE, mIsMultiuser ? UserHandle.OWNER : UserHandle.CURRENT);
}
public static boolean isSignatureMatch(Signature[] signatures,
List<HashSet<Signature>> sigSets) {
if (signatures == null) return false;
// build hashset of input to test against
HashSet<Signature> inputSet = new HashSet<Signature>();
for (Signature s : signatures) {
inputSet.add(s);
}
// test input against each of the signature sets
for (HashSet<Signature> referenceSet : sigSets) {
if (referenceSet.equals(inputSet)) {
return true;
}
}
return false;
}
private boolean isSignatureMatch(Signature[] signatures) {
return isSignatureMatch(signatures, mSignatureSets);
}
private final PackageMonitor mPackageMonitor = new PackageMonitor() {
/**
* Called when package has been reinstalled
*/
@Override
public void onPackageUpdateFinished(String packageName, int uid) {
synchronized (mLock) {
if (packageName.equals(mPackageName)) {
// package updated, make sure to rebind
unbindLocked();
}
// Need to check all packages because this method is also called when a
// system app is uninstalled and the stock version in reinstalled.
bindBestPackageLocked(null);
}
}
@Override
public void onPackageAdded(String packageName, int uid) {
synchronized (mLock) {
if (packageName.equals(mPackageName)) {
// package updated, make sure to rebind
unbindLocked();
}
// check the new package is case it is better
bindBestPackageLocked(null);
}
}
@Override
public void onPackageRemoved(String packageName, int uid) {
synchronized (mLock) {
if (packageName.equals(mPackageName)) {
unbindLocked();
// the currently bound package was removed,
// need to search for a new package
bindBestPackageLocked(null);
}
}
}
@Override
public boolean onPackageChanged(String packageName, int uid, String[] components) {
synchronized (mLock) {
if (packageName.equals(mPackageName)) {
// service enabled or disabled, make sure to rebind
unbindLocked();
}
// the service might be disabled, need to search for a new
// package
bindBestPackageLocked(null);
}
return super.onPackageChanged(packageName, uid, components);
}
};
@Override
public void onServiceConnected(ComponentName name, IBinder binder) {
synchronized (mLock) {
String packageName = name.getPackageName();
if (packageName.equals(mPackageName)) {
if (D) Log.d(mTag, packageName + " connected");
mBinder = binder;
if (mHandler !=null && mNewServiceWork != null) {
mHandler.post(mNewServiceWork);
}
} else {
Log.w(mTag, "unexpected onServiceConnected: " + packageName);
}
}
}
@Override
public void onServiceDisconnected(ComponentName name) {
synchronized (mLock) {
String packageName = name.getPackageName();
if (D) Log.d(mTag, packageName + " disconnected");
if (packageName.equals(mPackageName)) {
mBinder = null;
}
}
}
public String getBestPackageName() {
synchronized (mLock) {
return mPackageName;
}
}
public int getBestVersion() {
synchronized (mLock) {
return mVersion;
}
}
public IBinder getBinder() {
synchronized (mLock) {
return mBinder;
}
}
public void switchUser() {
synchronized (mLock) {
if (!mIsMultiuser) {
unbindLocked();
bindBestPackageLocked(mServicePackageName);
}
}
}
}
|