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
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
|
/*
* Copyright (C) 2013 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.print;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Binder;
import android.os.Build;
import android.os.Handler;
import android.os.IBinder;
import android.os.IBinder.DeathRecipient;
import android.os.Looper;
import android.os.Message;
import android.os.ParcelFileDescriptor;
import android.os.RemoteException;
import android.os.UserHandle;
import android.print.IPrinterDiscoverySessionController;
import android.print.IPrinterDiscoverySessionObserver;
import android.print.PrintJobInfo;
import android.print.PrintManager;
import android.print.PrinterId;
import android.print.PrinterInfo;
import android.printservice.IPrintService;
import android.printservice.IPrintServiceClient;
import android.util.Slog;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.List;
/**
* This class represents a remote print service. It abstracts away the binding
* and unbinding from the remote implementation. Clients can call methods of
* this class without worrying about when and how to bind/unbind.
*/
final class RemotePrintService implements DeathRecipient {
private static final String LOG_TAG = "RemotePrintService";
private static final boolean DEBUG = true && Build.IS_DEBUGGABLE;
private final Context mContext;
private final ComponentName mComponentName;
private final Intent mIntent;
private final RemotePrintSpooler mSpooler;
private final int mUserId;
private final List<Runnable> mPendingCommands = new ArrayList<Runnable>();
private final ServiceConnection mServiceConnection = new RemoteServiceConneciton();
private final RemotePrintServiceClient mPrintServiceClient;
private final Handler mHandler;
private IPrintService mPrintService;
private boolean mBinding;
private boolean mDestroyed;
public RemotePrintService(Context context, ComponentName componentName, int userId,
RemotePrintSpooler spooler) {
mContext = context;
mComponentName = componentName;
mIntent = new Intent().setComponent(mComponentName);
mUserId = userId;
mSpooler = spooler;
mHandler = new MyHandler(context.getMainLooper());
mPrintServiceClient = new RemotePrintServiceClient(this);
}
public void destroy() {
mHandler.sendEmptyMessage(MyHandler.MSG_DESTROY);
}
private void handleDestroy() {
throwIfDestroyed();
ensureUnbound();
mDestroyed = true;
}
public void onAllPrintJobsHandled() {
mHandler.sendEmptyMessage(MyHandler.MSG_ON_ALL_PRINT_JOBS_HANDLED);
}
@Override
public void binderDied() {
mHandler.sendEmptyMessage(MyHandler.MSG_BINDER_DIED);
}
private void handleBinderDied() {
ensureUnbound();
}
private void handleOnAllPrintJobsHandled() {
throwIfDestroyed();
if (isBound()) {
if (DEBUG) {
Slog.i(LOG_TAG, "[user: " + mUserId + "] handleOnAllPrintJobsHandled()");
}
// If bound and all the work is completed, then unbind.
ensureUnbound();
}
}
public void onRequestCancelPrintJob(PrintJobInfo printJob) {
mHandler.obtainMessage(MyHandler.MSG_ON_REQUEST_CANCEL_PRINT_JOB,
printJob).sendToTarget();
}
private void handleRequestCancelPrintJob(final PrintJobInfo printJob) {
throwIfDestroyed();
// If we are not bound, then we have no print jobs to handle
// which means that there are no print jobs to be cancelled.
if (isBound()) {
if (DEBUG) {
Slog.i(LOG_TAG, "[user: " + mUserId + "] handleRequestCancelPrintJob()");
}
try {
mPrintService.requestCancelPrintJob(printJob);
} catch (RemoteException re) {
Slog.e(LOG_TAG, "Error canceling a pring job.", re);
}
}
}
public void onPrintJobQueued(PrintJobInfo printJob) {
mHandler.obtainMessage(MyHandler.MSG_ON_PRINT_JOB_QUEUED,
printJob).sendToTarget();
}
private void handleOnPrintJobQueued(final PrintJobInfo printJob) {
throwIfDestroyed();
if (!isBound()) {
ensureBound();
mPendingCommands.add(new Runnable() {
@Override
public void run() {
handleOnPrintJobQueued(printJob);
}
});
} else {
if (DEBUG) {
Slog.i(LOG_TAG, "[user: " + mUserId + "] handleOnPrintJobQueued()");
}
try {
mPrintService.onPrintJobQueued(printJob);
} catch (RemoteException re) {
Slog.e(LOG_TAG, "Error announcing queued pring job.", re);
}
}
}
public void createPrinterDiscoverySession(IPrinterDiscoverySessionObserver observer) {
mHandler.obtainMessage(MyHandler.MSG_CREATE_PRINTER_DISCOVERY_SESSION,
observer).sendToTarget();
}
private void handleCreatePrinterDiscoverySession(
final IPrinterDiscoverySessionObserver observer) {
throwIfDestroyed();
if (!isBound()) {
ensureBound();
mPendingCommands.add(new Runnable() {
@Override
public void run() {
handleCreatePrinterDiscoverySession(observer);
}
});
} else {
if (DEBUG) {
Slog.i(LOG_TAG, "[user: " + mUserId + "] createPrinterDiscoverySession()");
}
try {
mPrintService.createPrinterDiscoverySession(observer);
} catch (RemoteException re) {
Slog.e(LOG_TAG, "Error announcing start printer dicovery.", re);
}
}
}
private boolean isBound() {
return mPrintService != null;
}
private void ensureBound() {
if (isBound() || mBinding) {
return;
}
if (DEBUG) {
Slog.i(LOG_TAG, "[user: " + mUserId + "] ensureBound()");
}
mBinding = true;
mContext.bindServiceAsUser(mIntent, mServiceConnection,
Context.BIND_AUTO_CREATE, new UserHandle(mUserId));
}
private void ensureUnbound() {
if (!isBound() && !mBinding) {
return;
}
if (DEBUG) {
Slog.i(LOG_TAG, "[user: " + mUserId + "] ensureUnbound()");
}
mBinding = false;
mPendingCommands.clear();
if (isBound()) {
try {
mPrintService.setClient(null);
} catch (RemoteException re) {
/* ignore */
}
mPrintService.asBinder().unlinkToDeath(this, 0);
mPrintService = null;
mContext.unbindService(mServiceConnection);
}
}
private void throwIfDestroyed() {
if (mDestroyed) {
throw new IllegalStateException("Cannot interact with a destroyed service");
}
}
private class RemoteServiceConneciton implements ServiceConnection {
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
if (mDestroyed || !mBinding) {
return;
}
mBinding = false;
mPrintService = IPrintService.Stub.asInterface(service);
try {
service.linkToDeath(RemotePrintService.this, 0);
} catch (RemoteException re) {
handleBinderDied();
return;
}
try {
mPrintService.setClient(mPrintServiceClient);
} catch (RemoteException re) {
Slog.e(LOG_TAG, "Error setting client for: " + service, re);
handleBinderDied();
return;
}
final int pendingCommandCount = mPendingCommands.size();
for (int i = 0; i < pendingCommandCount; i++) {
Runnable pendingCommand = mPendingCommands.get(i);
pendingCommand.run();
}
}
@Override
public void onServiceDisconnected(ComponentName name) {
mBinding = true;
}
}
private final class MyHandler extends Handler {
public static final int MSG_ON_ALL_PRINT_JOBS_HANDLED = 1;
public static final int MSG_ON_REQUEST_CANCEL_PRINT_JOB = 2;
public static final int MSG_ON_PRINT_JOB_QUEUED = 3;
public static final int MSG_CREATE_PRINTER_DISCOVERY_SESSION = 4;
public static final int MSG_DESTROY = 6;
public static final int MSG_BINDER_DIED = 7;
public MyHandler(Looper looper) {
super(looper, null, false);
}
@Override
public void handleMessage(Message message) {
switch (message.what) {
case MSG_ON_ALL_PRINT_JOBS_HANDLED: {
handleOnAllPrintJobsHandled();
} break;
case MSG_ON_REQUEST_CANCEL_PRINT_JOB: {
PrintJobInfo printJob = (PrintJobInfo) message.obj;
handleRequestCancelPrintJob(printJob);
} break;
case MSG_ON_PRINT_JOB_QUEUED: {
PrintJobInfo printJob = (PrintJobInfo) message.obj;
handleOnPrintJobQueued(printJob);
} break;
case MSG_CREATE_PRINTER_DISCOVERY_SESSION: {
IPrinterDiscoverySessionObserver observer =
(IPrinterDiscoverySessionObserver) message.obj;
handleCreatePrinterDiscoverySession(new SecurePrinterDiscoverySessionObserver(
mComponentName, observer));
} break;
case MSG_DESTROY: {
handleDestroy();
} break;
case MSG_BINDER_DIED: {
handleBinderDied();
} break;
}
}
}
private static final class RemotePrintServiceClient extends IPrintServiceClient.Stub {
private final WeakReference<RemotePrintService> mWeakService;
public RemotePrintServiceClient(RemotePrintService service) {
mWeakService = new WeakReference<RemotePrintService>(service);
}
@Override
public List<PrintJobInfo> getPrintJobInfos() {
RemotePrintService service = mWeakService.get();
if (service != null) {
final long identity = Binder.clearCallingIdentity();
try {
return service.mSpooler.getPrintJobInfos(service.mComponentName,
PrintJobInfo.STATE_ANY_VISIBLE_TO_CLIENTS, PrintManager.APP_ID_ANY);
} finally {
Binder.restoreCallingIdentity(identity);
}
}
return null;
}
@Override
public PrintJobInfo getPrintJobInfo(int printJobId) {
RemotePrintService service = mWeakService.get();
if (service != null) {
final long identity = Binder.clearCallingIdentity();
try {
return service.mSpooler.getPrintJobInfo(printJobId,
PrintManager.APP_ID_ANY);
} finally {
Binder.restoreCallingIdentity(identity);
}
}
return null;
}
@Override
public boolean setPrintJobState(int printJobId, int state, CharSequence error) {
RemotePrintService service = mWeakService.get();
if (service != null) {
final long identity = Binder.clearCallingIdentity();
try {
return service.mSpooler.setPrintJobState(printJobId, state, error);
} finally {
Binder.restoreCallingIdentity(identity);
}
}
return false;
}
@Override
public boolean setPrintJobTag(int printJobId, String tag) {
RemotePrintService service = mWeakService.get();
if (service != null) {
final long identity = Binder.clearCallingIdentity();
try {
return service.mSpooler.setPrintJobTag(printJobId, tag);
} finally {
Binder.restoreCallingIdentity(identity);
}
}
return false;
}
@Override
public void writePrintJobData(ParcelFileDescriptor fd, int printJobId) {
RemotePrintService service = mWeakService.get();
if (service != null) {
final long identity = Binder.clearCallingIdentity();
try {
service.mSpooler.writePrintJobData(fd, printJobId);
} finally {
Binder.restoreCallingIdentity(identity);
}
}
}
}
private static final class SecurePrinterDiscoverySessionObserver
extends IPrinterDiscoverySessionObserver.Stub {
private final ComponentName mComponentName;
private final IPrinterDiscoverySessionObserver mDecoratedObsever;
public SecurePrinterDiscoverySessionObserver(ComponentName componentName,
IPrinterDiscoverySessionObserver observer) {
mComponentName = componentName;
mDecoratedObsever = observer;
}
@Override
public void onPrintersAdded(List<PrinterInfo> printers) {
throwIfPrinterIdsForPrinterInfoTampered(printers);
try {
mDecoratedObsever.onPrintersAdded(printers);
} catch (RemoteException re) {
Slog.e(LOG_TAG, "Error delegating to onPrintersAdded", re);
}
}
@Override
public void onPrintersUpdated(List<PrinterInfo> printers) {
throwIfPrinterIdsForPrinterInfoTampered(printers);
try {
mDecoratedObsever.onPrintersUpdated(printers);
} catch (RemoteException re) {
Slog.e(LOG_TAG, "Error delegating to onPrintersUpdated.", re);
}
}
@Override
public void onPrintersRemoved(List<PrinterId> printerIds) {
throwIfPrinterIdsTampered(printerIds);
try {
mDecoratedObsever.onPrintersRemoved(printerIds);
} catch (RemoteException re) {
Slog.e(LOG_TAG, "Error delegating to onPrintersRemoved", re);
}
}
@Override
public void setController(IPrinterDiscoverySessionController controller) {
try {
mDecoratedObsever.setController(controller);
} catch (RemoteException re) {
Slog.e(LOG_TAG, "Error setting controller", re);
}
}
private void throwIfPrinterIdsForPrinterInfoTampered(
List<PrinterInfo> printerInfos) {
final int printerInfoCount = printerInfos.size();
for (int i = 0; i < printerInfoCount; i++) {
PrinterId printerId = printerInfos.get(i).getId();
throwIfPrinterIdTampered(printerId);
}
}
private void throwIfPrinterIdsTampered(List<PrinterId> printerIds) {
final int printerIdCount = printerIds.size();
for (int i = 0; i < printerIdCount; i++) {
PrinterId printerId = printerIds.get(i);
throwIfPrinterIdTampered(printerId);
}
}
private void throwIfPrinterIdTampered(PrinterId printerId) {
if (printerId == null || printerId.getServiceName() == null
|| !printerId.getServiceName().equals(mComponentName)) {
throw new IllegalArgumentException("Invalid printer id: " + printerId);
}
}
}
}
|