-
Notifications
You must be signed in to change notification settings - Fork 6
/
VolumeManager.cpp
1965 lines (1666 loc) · 57.4 KB
/
VolumeManager.cpp
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
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* Copyright (C) 2008 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.
*/
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <fts.h>
#include <mntent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/sysmacros.h>
#include <sys/wait.h>
#include <unistd.h>
#include <linux/kdev_t.h>
#define LOG_TAG "Vold"
#include <openssl/md5.h>
#include <android-base/logging.h>
#include <android-base/stringprintf.h>
#include <cutils/fs.h>
#include <cutils/log.h>
#include <selinux/android.h>
#include <sysutils/NetlinkEvent.h>
#include <private/android_filesystem_config.h>
#include "Benchmark.h"
#include "EmulatedVolume.h"
#include "VolumeManager.h"
#include "NetlinkManager.h"
#include "ResponseCode.h"
#include "Loop.h"
#include "fs/Ext4.h"
#include "fs/Vfat.h"
#include "Utils.h"
#include "Devmapper.h"
#include "Process.h"
#include "Asec.h"
#include "VoldUtil.h"
#include "cryptfs.h"
#define MASS_STORAGE_FILE_PATH "/sys/class/android_usb/android0/f_mass_storage/lun/file"
#define ROUND_UP_POWER_OF_2(number, po2) (((!!((number) & ((1U << (po2)) - 1))) << (po2))\
+ ((number) & (~((1U << (po2)) - 1))))
using android::base::StringPrintf;
/*
* Path to external storage where *only* root can access ASEC image files
*/
const char *VolumeManager::SEC_ASECDIR_EXT = "/mnt/secure/asec";
/*
* Path to internal storage where *only* root can access ASEC image files
*/
const char *VolumeManager::SEC_ASECDIR_INT = "/data/app-asec";
/*
* Path to where secure containers are mounted
*/
const char *VolumeManager::ASECDIR = "/mnt/asec";
/*
* Path to where OBBs are mounted
*/
const char *VolumeManager::LOOPDIR = "/mnt/obb";
bool VolumeManager::shutting_down = false;
static const char* kPathUserMount = "/mnt/user";
static const char* kPathVirtualDisk = "/data/misc/vold/virtual_disk";
static const char* kPropVirtualDisk = "persist.sys.virtual_disk";
/* 512MiB is large enough for testing purposes */
static const unsigned int kSizeVirtualDisk = 536870912;
static const unsigned int kMajorBlockMmc = 179;
static const unsigned int kMajorBlockExperimentalMin = 240;
static const unsigned int kMajorBlockExperimentalMax = 254;
/* writes superblock at end of file or device given by name */
static int writeSuperBlock(const char* name, struct asec_superblock *sb, unsigned int numImgSectors) {
int sbfd = open(name, O_RDWR | O_CLOEXEC);
if (sbfd < 0) {
SLOGE("Failed to open %s for superblock write (%s)", name, strerror(errno));
return -1;
}
if (lseek(sbfd, (numImgSectors * 512), SEEK_SET) < 0) {
SLOGE("Failed to lseek for superblock (%s)", strerror(errno));
close(sbfd);
return -1;
}
if (write(sbfd, sb, sizeof(struct asec_superblock)) != sizeof(struct asec_superblock)) {
SLOGE("Failed to write superblock (%s)", strerror(errno));
close(sbfd);
return -1;
}
close(sbfd);
return 0;
}
static unsigned long adjustSectorNumExt4(unsigned long numSectors) {
// Ext4 started to reserve 2% or 4096 clusters, whichever is smaller for
// preventing costly operations or unexpected ENOSPC error.
// Ext4::format() uses default block size without clustering.
unsigned long clusterSectors = 4096 / 512;
unsigned long reservedSectors = (numSectors * 2)/100 + (numSectors % 50 > 0);
numSectors += reservedSectors > (4096 * clusterSectors) ? (4096 * clusterSectors) : reservedSectors;
return ROUND_UP_POWER_OF_2(numSectors, 3);
}
static unsigned long adjustSectorNumFAT(unsigned long numSectors) {
/*
* Add some headroom
*/
unsigned long fatSize = (((numSectors * 4) / 512) + 1) * 2;
numSectors += fatSize + 2;
/*
* FAT is aligned to 32 kb with 512b sectors.
*/
return ROUND_UP_POWER_OF_2(numSectors, 6);
}
static int setupLoopDevice(char* buffer, size_t len, const char* asecFileName, const char* idHash, bool debug) {
if (Loop::lookupActive(idHash, buffer, len)) {
if (Loop::create(idHash, asecFileName, buffer, len)) {
SLOGE("ASEC loop device creation failed for %s (%s)", asecFileName, strerror(errno));
return -1;
}
if (debug) {
SLOGD("New loop device created at %s", buffer);
}
} else {
if (debug) {
SLOGD("Found active loopback for %s at %s", asecFileName, buffer);
}
}
return 0;
}
static int setupDevMapperDevice(char* buffer, size_t len, const char* loopDevice, const char* asecFileName, const char* key, const char* idHash , unsigned long numImgSectors, bool* createdDMDevice, bool debug) {
if (strcmp(key, "none")) {
if (Devmapper::lookupActive(idHash, buffer, len)) {
if (Devmapper::create(idHash, loopDevice, key, numImgSectors,
buffer, len)) {
SLOGE("ASEC device mapping failed for %s (%s)", asecFileName, strerror(errno));
return -1;
}
if (debug) {
SLOGD("New devmapper instance created at %s", buffer);
}
} else {
if (debug) {
SLOGD("Found active devmapper for %s at %s", asecFileName, buffer);
}
}
*createdDMDevice = true;
} else {
strlcpy(buffer, loopDevice, len);
*createdDMDevice = false;
}
return 0;
}
static void waitForDevMapper(const char *dmDevice) {
/*
* Wait for the device mapper node to be created. Sometimes it takes a
* while. Wait for up to 1 second. We could also inspect incoming uevents,
* but that would take more effort.
*/
int tries = 25;
while (tries--) {
if (!access(dmDevice, F_OK) || errno != ENOENT) {
break;
}
usleep(40 * 1000);
}
}
VolumeManager *VolumeManager::sInstance = NULL;
VolumeManager *VolumeManager::Instance() {
if (!sInstance)
sInstance = new VolumeManager();
return sInstance;
}
VolumeManager::VolumeManager() {
mDebug = false;
mActiveContainers = new AsecIdCollection();
mBroadcaster = NULL;
mUmsSharingCount = 0;
mSavedDirtyRatio = -1;
// set dirty ratio to 0 when UMS is active
mUmsDirtyRatio = 0;
}
VolumeManager::~VolumeManager() {
delete mActiveContainers;
}
char *VolumeManager::asecHash(const char *id, char *buffer, size_t len) {
static const char* digits = "0123456789abcdef";
unsigned char sig[MD5_DIGEST_LENGTH];
if (buffer == NULL) {
SLOGE("Destination buffer is NULL");
errno = ESPIPE;
return NULL;
} else if (id == NULL) {
SLOGE("Source buffer is NULL");
errno = ESPIPE;
return NULL;
} else if (len < MD5_ASCII_LENGTH_PLUS_NULL) {
SLOGE("Target hash buffer size < %d bytes (%zu)",
MD5_ASCII_LENGTH_PLUS_NULL, len);
errno = ESPIPE;
return NULL;
}
MD5(reinterpret_cast<const unsigned char*>(id), strlen(id), sig);
char *p = buffer;
for (int i = 0; i < MD5_DIGEST_LENGTH; i++) {
*p++ = digits[sig[i] >> 4];
*p++ = digits[sig[i] & 0x0F];
}
*p = '\0';
return buffer;
}
int VolumeManager::updateVirtualDisk() {
if (property_get_bool(kPropVirtualDisk, false)) {
if (access(kPathVirtualDisk, F_OK) != 0) {
Loop::createImageFile(kPathVirtualDisk, kSizeVirtualDisk / 512);
}
if (mVirtualDisk == nullptr) {
if (Loop::create(kPathVirtualDisk, mVirtualDiskPath) != 0) {
LOG(ERROR) << "Failed to create virtual disk";
return -1;
}
struct stat buf;
if (stat(mVirtualDiskPath.c_str(), &buf) < 0) {
PLOG(ERROR) << "Failed to stat " << mVirtualDiskPath;
return -1;
}
auto disk = new android::vold::Disk("virtual", buf.st_rdev, "virtual",
android::vold::Disk::Flags::kAdoptable | android::vold::Disk::Flags::kSd);
disk->create();
mVirtualDisk = std::shared_ptr<android::vold::Disk>(disk);
mDisks.push_back(mVirtualDisk);
}
} else {
if (mVirtualDisk != nullptr) {
dev_t device = mVirtualDisk->getDevice();
auto i = mDisks.begin();
while (i != mDisks.end()) {
if ((*i)->getDevice() == device) {
(*i)->destroy();
i = mDisks.erase(i);
} else {
++i;
}
}
Loop::destroyByDevice(mVirtualDiskPath.c_str());
mVirtualDisk = nullptr;
}
if (access(kPathVirtualDisk, F_OK) == 0) {
unlink(kPathVirtualDisk);
}
}
return 0;
}
int VolumeManager::setDebug(bool enable) {
mDebug = enable;
return 0;
}
int VolumeManager::start() {
// Always start from a clean slate by unmounting everything in
// directories that we own, in case we crashed.
unmountAll();
// Assume that we always have an emulated volume on internal
// storage; the framework will decide if it should be mounted.
CHECK(mInternalEmulated == nullptr);
mInternalEmulated = std::shared_ptr<android::vold::VolumeBase>(
new android::vold::EmulatedVolume("/data/media"));
mInternalEmulated->create();
// Consider creating a virtual disk
updateVirtualDisk();
return 0;
}
int VolumeManager::stop() {
CHECK(mInternalEmulated != nullptr);
mInternalEmulated->destroy();
mInternalEmulated = nullptr;
return 0;
}
void VolumeManager::handleBlockEvent(NetlinkEvent *evt) {
std::lock_guard<std::mutex> lock(mLock);
if (mDebug) {
LOG(VERBOSE) << "----------------";
LOG(VERBOSE) << "handleBlockEvent with action " << (int) evt->getAction();
evt->dump();
}
std::string eventPath(evt->findParam("DEVPATH")?evt->findParam("DEVPATH"):"");
std::string devType(evt->findParam("DEVTYPE")?evt->findParam("DEVTYPE"):"");
if (devType != "disk") return;
int major = atoi(evt->findParam("MAJOR"));
int minor = atoi(evt->findParam("MINOR"));
dev_t device = makedev(major, minor);
switch (evt->getAction()) {
case NetlinkEvent::Action::kAdd: {
for (const auto& source : mDiskSources) {
if (source->matches(eventPath)) {
// For now, assume that MMC, virtio-blk (the latter is
// emulator-specific; see Disk.cpp for details) and UFS card
// devices are SD, and that everything else is USB
int flags = source->getFlags();
if (major == kMajorBlockMmc
|| (eventPath.find("ufs") != std::string::npos)
|| (android::vold::IsRunningInEmulator()
&& major >= (int) kMajorBlockExperimentalMin
&& major <= (int) kMajorBlockExperimentalMax)) {
flags |= android::vold::Disk::Flags::kSd;
} else {
flags |= android::vold::Disk::Flags::kUsb;
}
auto disk = new android::vold::Disk(eventPath, device,
source->getNickname(), flags);
disk->create();
mDisks.push_back(std::shared_ptr<android::vold::Disk>(disk));
break;
}
}
break;
}
case NetlinkEvent::Action::kChange: {
LOG(DEBUG) << "Disk at " << major << ":" << minor << " changed";
for (const auto& disk : mDisks) {
if (disk->getDevice() == device) {
disk->readMetadata();
disk->readPartitions();
}
}
break;
}
case NetlinkEvent::Action::kRemove: {
auto i = mDisks.begin();
while (i != mDisks.end()) {
if ((*i)->getDevice() == device) {
(*i)->destroy();
i = mDisks.erase(i);
} else {
++i;
}
}
break;
}
default: {
LOG(WARNING) << "Unexpected block event action " << (int) evt->getAction();
break;
}
}
}
void VolumeManager::addDiskSource(const std::shared_ptr<DiskSource>& diskSource) {
std::lock_guard<std::mutex> lock(mLock);
mDiskSources.push_back(diskSource);
}
std::shared_ptr<android::vold::Disk> VolumeManager::findDisk(const std::string& id) {
for (auto disk : mDisks) {
if (disk->getId() == id) {
return disk;
}
}
return nullptr;
}
std::shared_ptr<android::vold::VolumeBase> VolumeManager::findVolume(const std::string& id) {
// Vold could receive "mount" after "shutdown" command in the extreme case.
// If this happens, mInternalEmulated will equal nullptr and
// we need to deal with it in order to avoid null pointer crash.
if (mInternalEmulated != nullptr && mInternalEmulated->getId() == id) {
return mInternalEmulated;
}
for (const auto& disk : mDisks) {
auto vol = disk->findVolume(id);
if (vol != nullptr) {
return vol;
}
}
return nullptr;
}
void VolumeManager::listVolumes(android::vold::VolumeBase::Type type,
std::list<std::string>& list) {
list.clear();
for (const auto& disk : mDisks) {
disk->listVolumes(type, list);
}
}
nsecs_t VolumeManager::benchmarkPrivate(const std::string& id) {
std::string path;
if (id == "private" || id == "null") {
path = "/data";
} else {
auto vol = findVolume(id);
if (vol != nullptr && vol->getState() == android::vold::VolumeBase::State::kMounted) {
path = vol->getPath();
}
}
if (path.empty()) {
LOG(WARNING) << "Failed to find volume for " << id;
return -1;
}
return android::vold::BenchmarkPrivate(path);
}
int VolumeManager::forgetPartition(const std::string& partGuid) {
std::string normalizedGuid;
if (android::vold::NormalizeHex(partGuid, normalizedGuid)) {
LOG(WARNING) << "Invalid GUID " << partGuid;
return -1;
}
std::string keyPath = android::vold::BuildKeyPath(normalizedGuid);
if (unlink(keyPath.c_str()) != 0) {
LOG(ERROR) << "Failed to unlink " << keyPath;
return -1;
}
return 0;
}
int VolumeManager::linkPrimary(userid_t userId) {
std::string source(mPrimary->getPath());
if (mPrimary->getType() == android::vold::VolumeBase::Type::kEmulated) {
source = StringPrintf("%s/%d", source.c_str(), userId);
fs_prepare_dir(source.c_str(), 0755, AID_ROOT, AID_ROOT);
}
std::string target(StringPrintf("/mnt/user/%d/primary", userId));
if (TEMP_FAILURE_RETRY(unlink(target.c_str()))) {
if (errno != ENOENT) {
SLOGW("Failed to unlink %s: %s", target.c_str(), strerror(errno));
}
}
LOG(DEBUG) << "Linking " << source << " to " << target;
if (TEMP_FAILURE_RETRY(symlink(source.c_str(), target.c_str()))) {
SLOGW("Failed to link %s to %s: %s", source.c_str(), target.c_str(),
strerror(errno));
return -errno;
}
return 0;
}
int VolumeManager::onUserAdded(userid_t userId, int userSerialNumber) {
mAddedUsers[userId] = userSerialNumber;
return 0;
}
int VolumeManager::onUserRemoved(userid_t userId) {
mAddedUsers.erase(userId);
return 0;
}
int VolumeManager::onUserStarted(userid_t userId) {
// Note that sometimes the system will spin up processes from Zygote
// before actually starting the user, so we're okay if Zygote
// already created this directory.
std::string path(StringPrintf("%s/%d", kPathUserMount, userId));
fs_prepare_dir(path.c_str(), 0755, AID_ROOT, AID_ROOT);
mStartedUsers.insert(userId);
if (mPrimary) {
linkPrimary(userId);
}
return 0;
}
int VolumeManager::onUserStopped(userid_t userId) {
mStartedUsers.erase(userId);
return 0;
}
int VolumeManager::setPrimary(const std::shared_ptr<android::vold::VolumeBase>& vol) {
mPrimary = vol;
for (userid_t userId : mStartedUsers) {
linkPrimary(userId);
}
return 0;
}
static int unmount_tree(const char* path) {
size_t path_len = strlen(path);
FILE* fp = setmntent("/proc/mounts", "r");
if (fp == NULL) {
ALOGE("Error opening /proc/mounts: %s", strerror(errno));
return -errno;
}
// Some volumes can be stacked on each other, so force unmount in
// reverse order to give us the best chance of success.
std::list<std::string> toUnmount;
mntent* mentry;
while ((mentry = getmntent(fp)) != NULL) {
if (strncmp(mentry->mnt_dir, path, path_len) == 0) {
toUnmount.push_front(std::string(mentry->mnt_dir));
}
}
endmntent(fp);
for (const auto& path : toUnmount) {
if (umount2(path.c_str(), MNT_DETACH)) {
ALOGW("Failed to unmount %s: %s", path.c_str(), strerror(errno));
}
}
return 0;
}
int VolumeManager::remountUid(uid_t uid, const std::string& mode) {
LOG(DEBUG) << "Remounting " << uid << " as mode " << mode;
DIR* dir;
struct dirent* de;
char rootName[PATH_MAX];
char pidName[PATH_MAX];
int pidFd;
int nsFd;
struct stat sb;
pid_t child;
if (!(dir = opendir("/proc"))) {
PLOG(ERROR) << "Failed to opendir";
return -1;
}
// Figure out root namespace to compare against below
if (android::vold::SaneReadLinkAt(dirfd(dir), "1/ns/mnt", rootName, PATH_MAX) == -1) {
PLOG(ERROR) << "Failed to readlink";
closedir(dir);
return -1;
}
// Poke through all running PIDs look for apps running as UID
while ((de = readdir(dir))) {
pidFd = -1;
nsFd = -1;
pidFd = openat(dirfd(dir), de->d_name, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
if (pidFd < 0) {
goto next;
}
if (fstat(pidFd, &sb) != 0) {
PLOG(WARNING) << "Failed to stat " << de->d_name;
goto next;
}
if (sb.st_uid != uid) {
goto next;
}
// Matches so far, but refuse to touch if in root namespace
LOG(DEBUG) << "Found matching PID " << de->d_name;
if (android::vold::SaneReadLinkAt(pidFd, "ns/mnt", pidName, PATH_MAX) == -1) {
PLOG(WARNING) << "Failed to read namespace for " << de->d_name;
goto next;
}
if (!strcmp(rootName, pidName)) {
LOG(WARNING) << "Skipping due to root namespace";
goto next;
}
// We purposefully leave the namespace open across the fork
nsFd = openat(pidFd, "ns/mnt", O_RDONLY); // not O_CLOEXEC
if (nsFd < 0) {
PLOG(WARNING) << "Failed to open namespace for " << de->d_name;
goto next;
}
if (!(child = fork())) {
if (setns(nsFd, CLONE_NEWNS) != 0) {
PLOG(ERROR) << "Failed to setns for " << de->d_name;
_exit(1);
}
unmount_tree("/storage");
std::string storageSource;
if (mode == "default") {
storageSource = "/mnt/runtime/default";
} else if (mode == "read") {
storageSource = "/mnt/runtime/read";
} else if (mode == "write") {
storageSource = "/mnt/runtime/write";
} else {
// Sane default of no storage visible
_exit(0);
}
if (TEMP_FAILURE_RETRY(mount(storageSource.c_str(), "/storage",
NULL, MS_BIND | MS_REC, NULL)) == -1) {
PLOG(ERROR) << "Failed to mount " << storageSource << " for "
<< de->d_name;
_exit(1);
}
if (TEMP_FAILURE_RETRY(mount(NULL, "/storage", NULL,
MS_REC | MS_SLAVE, NULL)) == -1) {
PLOG(ERROR) << "Failed to set MS_SLAVE to /storage for "
<< de->d_name;
_exit(1);
}
// Mount user-specific symlink helper into place
userid_t user_id = multiuser_get_user_id(uid);
std::string userSource(StringPrintf("/mnt/user/%d", user_id));
if (TEMP_FAILURE_RETRY(mount(userSource.c_str(), "/storage/self",
NULL, MS_BIND, NULL)) == -1) {
PLOG(ERROR) << "Failed to mount " << userSource << " for "
<< de->d_name;
_exit(1);
}
_exit(0);
}
if (child == -1) {
PLOG(ERROR) << "Failed to fork";
goto next;
} else {
TEMP_FAILURE_RETRY(waitpid(child, nullptr, 0));
}
next:
close(nsFd);
close(pidFd);
}
closedir(dir);
return 0;
}
int VolumeManager::reset() {
// Tear down all existing disks/volumes and start from a blank slate so
// newly connected framework hears all events.
if (mInternalEmulated != nullptr) {
mInternalEmulated->destroy();
mInternalEmulated->create();
}
for (const auto& disk : mDisks) {
disk->destroy();
disk->create();
}
updateVirtualDisk();
mAddedUsers.clear();
mStartedUsers.clear();
return 0;
}
// Can be called twice (sequentially) during shutdown. should be safe for that.
int VolumeManager::shutdown() {
if (mInternalEmulated == nullptr) {
return 0; // already shutdown
}
shutting_down = true;
mInternalEmulated->destroy();
mInternalEmulated = nullptr;
for (const auto& disk : mDisks) {
disk->destroy();
}
mDisks.clear();
shutting_down = false;
return 0;
}
int VolumeManager::unmountAll() {
std::lock_guard<std::mutex> lock(mLock);
// First, try gracefully unmounting all known devices
if (mInternalEmulated != nullptr) {
mInternalEmulated->unmount();
}
for (const auto& disk : mDisks) {
disk->unmountAll();
}
// Worst case we might have some stale mounts lurking around, so
// force unmount those just to be safe.
FILE* fp = setmntent("/proc/mounts", "r");
if (fp == NULL) {
SLOGE("Error opening /proc/mounts: %s", strerror(errno));
return -errno;
}
// Some volumes can be stacked on each other, so force unmount in
// reverse order to give us the best chance of success.
std::list<std::string> toUnmount;
mntent* mentry;
while ((mentry = getmntent(fp)) != NULL) {
if (strncmp(mentry->mnt_dir, "/mnt/", 5) == 0
|| strncmp(mentry->mnt_dir, "/storage/", 9) == 0) {
toUnmount.push_front(std::string(mentry->mnt_dir));
}
}
endmntent(fp);
for (const auto& path : toUnmount) {
SLOGW("Tearing down stale mount %s", path.c_str());
android::vold::ForceUnmount(path);
}
return 0;
}
int VolumeManager::getObbMountPath(const char *sourceFile, char *mountPath, int mountPathLen) {
char idHash[33];
if (!asecHash(sourceFile, idHash, sizeof(idHash))) {
SLOGE("Hash of '%s' failed (%s)", sourceFile, strerror(errno));
return -1;
}
memset(mountPath, 0, mountPathLen);
int written = snprintf(mountPath, mountPathLen, "%s/%s", VolumeManager::LOOPDIR, idHash);
if ((written < 0) || (written >= mountPathLen)) {
errno = EINVAL;
return -1;
}
if (access(mountPath, F_OK)) {
errno = ENOENT;
return -1;
}
return 0;
}
int VolumeManager::getAsecMountPath(const char *id, char *buffer, int maxlen) {
char asecFileName[255];
if (!isLegalAsecId(id)) {
SLOGE("getAsecMountPath: Invalid asec id \"%s\"", id);
errno = EINVAL;
return -1;
}
if (findAsec(id, asecFileName, sizeof(asecFileName))) {
SLOGE("Couldn't find ASEC %s", id);
return -1;
}
memset(buffer, 0, maxlen);
if (access(asecFileName, F_OK)) {
errno = ENOENT;
return -1;
}
int written = snprintf(buffer, maxlen, "%s/%s", VolumeManager::ASECDIR, id);
if ((written < 0) || (written >= maxlen)) {
SLOGE("getAsecMountPath failed for %s: couldn't construct path in buffer", id);
errno = EINVAL;
return -1;
}
return 0;
}
int VolumeManager::getAsecFilesystemPath(const char *id, char *buffer, int maxlen) {
char asecFileName[255];
if (!isLegalAsecId(id)) {
SLOGE("getAsecFilesystemPath: Invalid asec id \"%s\"", id);
errno = EINVAL;
return -1;
}
if (findAsec(id, asecFileName, sizeof(asecFileName))) {
SLOGE("Couldn't find ASEC %s", id);
return -1;
}
memset(buffer, 0, maxlen);
if (access(asecFileName, F_OK)) {
errno = ENOENT;
return -1;
}
int written = snprintf(buffer, maxlen, "%s", asecFileName);
if ((written < 0) || (written >= maxlen)) {
errno = EINVAL;
return -1;
}
return 0;
}
int VolumeManager::createAsec(const char *id, unsigned long numSectors, const char *fstype,
const char *key, const int ownerUid, bool isExternal) {
struct asec_superblock sb;
memset(&sb, 0, sizeof(sb));
if (!isLegalAsecId(id)) {
SLOGE("createAsec: Invalid asec id \"%s\"", id);
errno = EINVAL;
return -1;
}
const bool wantFilesystem = strcmp(fstype, "none");
bool usingExt4 = false;
if (wantFilesystem) {
usingExt4 = !strcmp(fstype, "ext4");
if (usingExt4) {
sb.c_opts |= ASEC_SB_C_OPTS_EXT4;
} else if (strcmp(fstype, "fat")) {
SLOGE("Invalid filesystem type %s", fstype);
errno = EINVAL;
return -1;
}
}
sb.magic = ASEC_SB_MAGIC;
sb.ver = ASEC_SB_VER;
if (numSectors < ((1024*1024)/512)) {
SLOGE("Invalid container size specified (%lu sectors)", numSectors);
errno = EINVAL;
return -1;
}
char asecFileName[255];
if (!findAsec(id, asecFileName, sizeof(asecFileName))) {
SLOGE("ASEC file '%s' currently exists - destroy it first! (%s)",
asecFileName, strerror(errno));
errno = EADDRINUSE;
return -1;
}
const char *asecDir = isExternal ? VolumeManager::SEC_ASECDIR_EXT : VolumeManager::SEC_ASECDIR_INT;
int written = snprintf(asecFileName, sizeof(asecFileName), "%s/%s.asec", asecDir, id);
if ((written < 0) || (size_t(written) >= sizeof(asecFileName))) {
errno = EINVAL;
return -1;
}
if (!access(asecFileName, F_OK)) {
SLOGE("ASEC file '%s' currently exists - destroy it first! (%s)",
asecFileName, strerror(errno));
errno = EADDRINUSE;
return -1;
}
unsigned long numImgSectors;
if (usingExt4)
numImgSectors = adjustSectorNumExt4(numSectors);
else
numImgSectors = adjustSectorNumFAT(numSectors);
// Add +1 for our superblock which is at the end
if (Loop::createImageFile(asecFileName, numImgSectors + 1)) {
SLOGE("ASEC image file creation failed (%s)", strerror(errno));
return -1;
}
char idHash[33];
if (!asecHash(id, idHash, sizeof(idHash))) {
SLOGE("Hash of '%s' failed (%s)", id, strerror(errno));
unlink(asecFileName);
return -1;
}
char loopDevice[255];
if (Loop::create(idHash, asecFileName, loopDevice, sizeof(loopDevice))) {
SLOGE("ASEC loop device creation failed (%s)", strerror(errno));
unlink(asecFileName);
return -1;
}
char dmDevice[255];
bool cleanupDm = false;
if (strcmp(key, "none")) {
// XXX: This is all we support for now
sb.c_cipher = ASEC_SB_C_CIPHER_TWOFISH;
if (Devmapper::create(idHash, loopDevice, key, numImgSectors, dmDevice,
sizeof(dmDevice))) {
SLOGE("ASEC device mapping failed (%s)", strerror(errno));
Loop::destroyByDevice(loopDevice);
unlink(asecFileName);
return -1;
}
cleanupDm = true;
} else {
sb.c_cipher = ASEC_SB_C_CIPHER_NONE;
strlcpy(dmDevice, loopDevice, sizeof(dmDevice));
}
/*
* Drop down the superblock at the end of the file
*/
if (writeSuperBlock(loopDevice, &sb, numImgSectors)) {
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
unlink(asecFileName);
return -1;
}
if (wantFilesystem) {
int formatStatus;
char mountPoint[255];
int written = snprintf(mountPoint, sizeof(mountPoint), "%s/%s", VolumeManager::ASECDIR, id);
if ((written < 0) || (size_t(written) >= sizeof(mountPoint))) {
SLOGE("ASEC fs format failed: couldn't construct mountPoint");
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
unlink(asecFileName);
return -1;
}
if (usingExt4) {
formatStatus = android::vold::ext4::Format(dmDevice, numImgSectors, mountPoint);
} else {
formatStatus = android::vold::vfat::Format(dmDevice, numImgSectors);
}
if (formatStatus < 0) {
SLOGE("ASEC fs format failed (%s)", strerror(errno));
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
unlink(asecFileName);
return -1;
}
if (mkdir(mountPoint, 0000)) {
if (errno != EEXIST) {
SLOGE("Mountpoint creation failed (%s)", strerror(errno));
if (cleanupDm) {
Devmapper::destroy(idHash);
}
Loop::destroyByDevice(loopDevice);
unlink(asecFileName);
return -1;
}