1 /*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "sehandle.h"
18 #include "Utils.h"
19 #include "Process.h"
20 #include "VolumeManager.h"
21
22 #include <android-base/file.h>
23 #include <android-base/logging.h>
24 #include <android-base/properties.h>
25 #include <android-base/stringprintf.h>
26 #include <cutils/fs.h>
27 #include <logwrap/logwrap.h>
28 #include <private/android_filesystem_config.h>
29
30 #include <mutex>
31 #include <dirent.h>
32 #include <fcntl.h>
33 #include <linux/fs.h>
34 #include <stdlib.h>
35 #include <sys/mount.h>
36 #include <sys/types.h>
37 #include <sys/stat.h>
38 #include <sys/sysmacros.h>
39 #include <sys/wait.h>
40 #include <sys/statvfs.h>
41
42 #ifndef UMOUNT_NOFOLLOW
43 #define UMOUNT_NOFOLLOW 0x00000008 /* Don't follow symlink on umount */
44 #endif
45
46 using android::base::ReadFileToString;
47 using android::base::StringPrintf;
48
49 namespace android {
50 namespace vold {
51
52 security_context_t sBlkidContext = nullptr;
53 security_context_t sBlkidUntrustedContext = nullptr;
54 security_context_t sFsckContext = nullptr;
55 security_context_t sFsckUntrustedContext = nullptr;
56
57 static const char* kBlkidPath = "/system/bin/blkid";
58 static const char* kKeyPath = "/data/misc/vold";
59
60 static const char* kProcFilesystems = "/proc/filesystems";
61
CreateDeviceNode(const std::string & path,dev_t dev)62 status_t CreateDeviceNode(const std::string& path, dev_t dev) {
63 const char* cpath = path.c_str();
64 status_t res = 0;
65
66 char* secontext = nullptr;
67 if (sehandle) {
68 if (!selabel_lookup(sehandle, &secontext, cpath, S_IFBLK)) {
69 setfscreatecon(secontext);
70 }
71 }
72
73 mode_t mode = 0660 | S_IFBLK;
74 if (mknod(cpath, mode, dev) < 0) {
75 if (errno != EEXIST) {
76 PLOG(ERROR) << "Failed to create device node for " << major(dev)
77 << ":" << minor(dev) << " at " << path;
78 res = -errno;
79 }
80 }
81
82 if (secontext) {
83 setfscreatecon(nullptr);
84 freecon(secontext);
85 }
86
87 return res;
88 }
89
DestroyDeviceNode(const std::string & path)90 status_t DestroyDeviceNode(const std::string& path) {
91 const char* cpath = path.c_str();
92 if (TEMP_FAILURE_RETRY(unlink(cpath))) {
93 return -errno;
94 } else {
95 return OK;
96 }
97 }
98
PrepareDir(const std::string & path,mode_t mode,uid_t uid,gid_t gid)99 status_t PrepareDir(const std::string& path, mode_t mode, uid_t uid, gid_t gid) {
100 const char* cpath = path.c_str();
101
102 char* secontext = nullptr;
103 if (sehandle) {
104 if (!selabel_lookup(sehandle, &secontext, cpath, S_IFDIR)) {
105 setfscreatecon(secontext);
106 }
107 }
108
109 int res = fs_prepare_dir(cpath, mode, uid, gid);
110
111 if (secontext) {
112 setfscreatecon(nullptr);
113 freecon(secontext);
114 }
115
116 if (res == 0) {
117 return OK;
118 } else {
119 return -errno;
120 }
121 }
122
ForceUnmount(const std::string & path)123 status_t ForceUnmount(const std::string& path) {
124 const char* cpath = path.c_str();
125 if (!umount2(cpath, UMOUNT_NOFOLLOW) || errno == EINVAL || errno == ENOENT) {
126 return OK;
127 }
128 // Apps might still be handling eject request, so wait before
129 // we start sending signals
130 if (!VolumeManager::shutting_down) sleep(5);
131
132 Process::killProcessesWithOpenFiles(cpath, SIGINT);
133 if (!VolumeManager::shutting_down) sleep(5);
134 if (!umount2(cpath, UMOUNT_NOFOLLOW) || errno == EINVAL || errno == ENOENT) {
135 return OK;
136 }
137
138 Process::killProcessesWithOpenFiles(cpath, SIGTERM);
139 if (!VolumeManager::shutting_down) sleep(5);
140 if (!umount2(cpath, UMOUNT_NOFOLLOW) || errno == EINVAL || errno == ENOENT) {
141 return OK;
142 }
143
144 Process::killProcessesWithOpenFiles(cpath, SIGKILL);
145 if (!VolumeManager::shutting_down) sleep(5);
146 if (!umount2(cpath, UMOUNT_NOFOLLOW) || errno == EINVAL || errno == ENOENT) {
147 return OK;
148 }
149
150 return -errno;
151 }
152
KillProcessesUsingPath(const std::string & path)153 status_t KillProcessesUsingPath(const std::string& path) {
154 const char* cpath = path.c_str();
155 if (Process::killProcessesWithOpenFiles(cpath, SIGINT) == 0) {
156 return OK;
157 }
158 if (!VolumeManager::shutting_down) sleep(5);
159
160 if (Process::killProcessesWithOpenFiles(cpath, SIGTERM) == 0) {
161 return OK;
162 }
163 if (!VolumeManager::shutting_down) sleep(5);
164
165 if (Process::killProcessesWithOpenFiles(cpath, SIGKILL) == 0) {
166 return OK;
167 }
168 if (!VolumeManager::shutting_down) sleep(5);
169
170 // Send SIGKILL a second time to determine if we've
171 // actually killed everyone with open files
172 if (Process::killProcessesWithOpenFiles(cpath, SIGKILL) == 0) {
173 return OK;
174 }
175 PLOG(ERROR) << "Failed to kill processes using " << path;
176 return -EBUSY;
177 }
178
BindMount(const std::string & source,const std::string & target)179 status_t BindMount(const std::string& source, const std::string& target) {
180 if (::mount(source.c_str(), target.c_str(), "", MS_BIND, NULL)) {
181 PLOG(ERROR) << "Failed to bind mount " << source << " to " << target;
182 return -errno;
183 }
184 return OK;
185 }
186
readMetadata(const std::string & path,std::string & fsType,std::string & fsUuid,std::string & fsLabel,bool untrusted)187 static status_t readMetadata(const std::string& path, std::string& fsType,
188 std::string& fsUuid, std::string& fsLabel, bool untrusted) {
189 fsType.clear();
190 fsUuid.clear();
191 fsLabel.clear();
192
193 std::vector<std::string> cmd;
194 cmd.push_back(kBlkidPath);
195 cmd.push_back("-c");
196 cmd.push_back("/dev/null");
197 cmd.push_back("-s");
198 cmd.push_back("TYPE");
199 cmd.push_back("-s");
200 cmd.push_back("UUID");
201 cmd.push_back("-s");
202 cmd.push_back("LABEL");
203 cmd.push_back(path);
204
205 std::vector<std::string> output;
206 status_t res = ForkExecvp(cmd, output, untrusted ? sBlkidUntrustedContext : sBlkidContext);
207 if (res != OK) {
208 LOG(WARNING) << "blkid failed to identify " << path;
209 return res;
210 }
211
212 char value[128];
213 for (const auto& line : output) {
214 // Extract values from blkid output, if defined
215 const char* cline = line.c_str();
216 const char* start = strstr(cline, "TYPE=\"");
217 if (start != nullptr && sscanf(start + 5, "\"%127[^\"]\"", value) == 1) {
218 fsType = value;
219 }
220
221 start = strstr(cline, "UUID=\"");
222 if (start != nullptr && sscanf(start + 5, "\"%127[^\"]\"", value) == 1) {
223 fsUuid = value;
224 }
225
226 start = strstr(cline, "LABEL=\"");
227 if (start != nullptr && sscanf(start + 6, "\"%127[^\"]\"", value) == 1) {
228 fsLabel = value;
229 }
230 }
231
232 return OK;
233 }
234
ReadMetadata(const std::string & path,std::string & fsType,std::string & fsUuid,std::string & fsLabel)235 status_t ReadMetadata(const std::string& path, std::string& fsType,
236 std::string& fsUuid, std::string& fsLabel) {
237 return readMetadata(path, fsType, fsUuid, fsLabel, false);
238 }
239
ReadMetadataUntrusted(const std::string & path,std::string & fsType,std::string & fsUuid,std::string & fsLabel)240 status_t ReadMetadataUntrusted(const std::string& path, std::string& fsType,
241 std::string& fsUuid, std::string& fsLabel) {
242 return readMetadata(path, fsType, fsUuid, fsLabel, true);
243 }
244
ForkExecvp(const std::vector<std::string> & args)245 status_t ForkExecvp(const std::vector<std::string>& args) {
246 return ForkExecvp(args, nullptr);
247 }
248
ForkExecvp(const std::vector<std::string> & args,security_context_t context)249 status_t ForkExecvp(const std::vector<std::string>& args, security_context_t context) {
250 size_t argc = args.size();
251 char** argv = (char**) calloc(argc, sizeof(char*));
252 for (size_t i = 0; i < argc; i++) {
253 argv[i] = (char*) args[i].c_str();
254 if (i == 0) {
255 LOG(VERBOSE) << args[i];
256 } else {
257 LOG(VERBOSE) << " " << args[i];
258 }
259 }
260
261 if (setexeccon(context)) {
262 LOG(ERROR) << "Failed to setexeccon";
263 abort();
264 }
265 status_t res = android_fork_execvp(argc, argv, NULL, false, true);
266 if (setexeccon(nullptr)) {
267 LOG(ERROR) << "Failed to setexeccon";
268 abort();
269 }
270
271 free(argv);
272 return res;
273 }
274
ForkExecvp(const std::vector<std::string> & args,std::vector<std::string> & output)275 status_t ForkExecvp(const std::vector<std::string>& args,
276 std::vector<std::string>& output) {
277 return ForkExecvp(args, output, nullptr);
278 }
279
ForkExecvp(const std::vector<std::string> & args,std::vector<std::string> & output,security_context_t context)280 status_t ForkExecvp(const std::vector<std::string>& args,
281 std::vector<std::string>& output, security_context_t context) {
282 std::string cmd;
283 for (size_t i = 0; i < args.size(); i++) {
284 cmd += args[i] + " ";
285 if (i == 0) {
286 LOG(VERBOSE) << args[i];
287 } else {
288 LOG(VERBOSE) << " " << args[i];
289 }
290 }
291 output.clear();
292
293 if (setexeccon(context)) {
294 LOG(ERROR) << "Failed to setexeccon";
295 abort();
296 }
297 FILE* fp = popen(cmd.c_str(), "r"); // NOLINT
298 if (setexeccon(nullptr)) {
299 LOG(ERROR) << "Failed to setexeccon";
300 abort();
301 }
302
303 if (!fp) {
304 PLOG(ERROR) << "Failed to popen " << cmd;
305 return -errno;
306 }
307 char line[1024];
308 while (fgets(line, sizeof(line), fp) != nullptr) {
309 LOG(VERBOSE) << line;
310 output.push_back(std::string(line));
311 }
312 if (pclose(fp) != 0) {
313 PLOG(ERROR) << "Failed to pclose " << cmd;
314 return -errno;
315 }
316
317 return OK;
318 }
319
ForkExecvpAsync(const std::vector<std::string> & args)320 pid_t ForkExecvpAsync(const std::vector<std::string>& args) {
321 size_t argc = args.size();
322 char** argv = (char**) calloc(argc + 1, sizeof(char*));
323 for (size_t i = 0; i < argc; i++) {
324 argv[i] = (char*) args[i].c_str();
325 if (i == 0) {
326 LOG(VERBOSE) << args[i];
327 } else {
328 LOG(VERBOSE) << " " << args[i];
329 }
330 }
331
332 pid_t pid = fork();
333 if (pid == 0) {
334 close(STDIN_FILENO);
335 close(STDOUT_FILENO);
336 close(STDERR_FILENO);
337
338 if (execvp(argv[0], argv)) {
339 PLOG(ERROR) << "Failed to exec";
340 }
341
342 _exit(1);
343 }
344
345 if (pid == -1) {
346 PLOG(ERROR) << "Failed to exec";
347 }
348
349 free(argv);
350 return pid;
351 }
352
ReadRandomBytes(size_t bytes,std::string & out)353 status_t ReadRandomBytes(size_t bytes, std::string& out) {
354 out.resize(bytes);
355 return ReadRandomBytes(bytes, &out[0]);
356 }
357
ReadRandomBytes(size_t bytes,char * buf)358 status_t ReadRandomBytes(size_t bytes, char* buf) {
359 int fd = TEMP_FAILURE_RETRY(open("/dev/urandom", O_RDONLY | O_CLOEXEC | O_NOFOLLOW));
360 if (fd == -1) {
361 return -errno;
362 }
363
364 size_t n;
365 while ((n = TEMP_FAILURE_RETRY(read(fd, &buf[0], bytes))) > 0) {
366 bytes -= n;
367 buf += n;
368 }
369 close(fd);
370
371 if (bytes == 0) {
372 return OK;
373 } else {
374 return -EIO;
375 }
376 }
377
GenerateRandomUuid(std::string & out)378 status_t GenerateRandomUuid(std::string& out) {
379 status_t res = ReadRandomBytes(16, out);
380 if (res == OK) {
381 out[6] &= 0x0f; /* clear version */
382 out[6] |= 0x40; /* set to version 4 */
383 out[8] &= 0x3f; /* clear variant */
384 out[8] |= 0x80; /* set to IETF variant */
385 }
386 return res;
387 }
388
HexToStr(const std::string & hex,std::string & str)389 status_t HexToStr(const std::string& hex, std::string& str) {
390 str.clear();
391 bool even = true;
392 char cur = 0;
393 for (size_t i = 0; i < hex.size(); i++) {
394 int val = 0;
395 switch (hex[i]) {
396 case ' ': case '-': case ':': continue;
397 case 'f': case 'F': val = 15; break;
398 case 'e': case 'E': val = 14; break;
399 case 'd': case 'D': val = 13; break;
400 case 'c': case 'C': val = 12; break;
401 case 'b': case 'B': val = 11; break;
402 case 'a': case 'A': val = 10; break;
403 case '9': val = 9; break;
404 case '8': val = 8; break;
405 case '7': val = 7; break;
406 case '6': val = 6; break;
407 case '5': val = 5; break;
408 case '4': val = 4; break;
409 case '3': val = 3; break;
410 case '2': val = 2; break;
411 case '1': val = 1; break;
412 case '0': val = 0; break;
413 default: return -EINVAL;
414 }
415
416 if (even) {
417 cur = val << 4;
418 } else {
419 cur += val;
420 str.push_back(cur);
421 cur = 0;
422 }
423 even = !even;
424 }
425 return even ? OK : -EINVAL;
426 }
427
428 static const char* kLookup = "0123456789abcdef";
429
StrToHex(const std::string & str,std::string & hex)430 status_t StrToHex(const std::string& str, std::string& hex) {
431 hex.clear();
432 for (size_t i = 0; i < str.size(); i++) {
433 hex.push_back(kLookup[(str[i] & 0xF0) >> 4]);
434 hex.push_back(kLookup[str[i] & 0x0F]);
435 }
436 return OK;
437 }
438
StrToHex(const KeyBuffer & str,KeyBuffer & hex)439 status_t StrToHex(const KeyBuffer& str, KeyBuffer& hex) {
440 hex.clear();
441 for (size_t i = 0; i < str.size(); i++) {
442 hex.push_back(kLookup[(str.data()[i] & 0xF0) >> 4]);
443 hex.push_back(kLookup[str.data()[i] & 0x0F]);
444 }
445 return OK;
446 }
447
NormalizeHex(const std::string & in,std::string & out)448 status_t NormalizeHex(const std::string& in, std::string& out) {
449 std::string tmp;
450 if (HexToStr(in, tmp)) {
451 return -EINVAL;
452 }
453 return StrToHex(tmp, out);
454 }
455
GetFreeBytes(const std::string & path)456 uint64_t GetFreeBytes(const std::string& path) {
457 struct statvfs sb;
458 if (statvfs(path.c_str(), &sb) == 0) {
459 return (uint64_t) sb.f_bavail * sb.f_frsize;
460 } else {
461 return -1;
462 }
463 }
464
465 // TODO: borrowed from frameworks/native/libs/diskusage/ which should
466 // eventually be migrated into system/
stat_size(struct stat * s)467 static int64_t stat_size(struct stat *s) {
468 int64_t blksize = s->st_blksize;
469 // count actual blocks used instead of nominal file size
470 int64_t size = s->st_blocks * 512;
471
472 if (blksize) {
473 /* round up to filesystem block size */
474 size = (size + blksize - 1) & (~(blksize - 1));
475 }
476
477 return size;
478 }
479
480 // TODO: borrowed from frameworks/native/libs/diskusage/ which should
481 // eventually be migrated into system/
calculate_dir_size(int dfd)482 int64_t calculate_dir_size(int dfd) {
483 int64_t size = 0;
484 struct stat s;
485 DIR *d;
486 struct dirent *de;
487
488 d = fdopendir(dfd);
489 if (d == NULL) {
490 close(dfd);
491 return 0;
492 }
493
494 while ((de = readdir(d))) {
495 const char *name = de->d_name;
496 if (fstatat(dfd, name, &s, AT_SYMLINK_NOFOLLOW) == 0) {
497 size += stat_size(&s);
498 }
499 if (de->d_type == DT_DIR) {
500 int subfd;
501
502 /* always skip "." and ".." */
503 if (name[0] == '.') {
504 if (name[1] == 0)
505 continue;
506 if ((name[1] == '.') && (name[2] == 0))
507 continue;
508 }
509
510 subfd = openat(dfd, name, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
511 if (subfd >= 0) {
512 size += calculate_dir_size(subfd);
513 }
514 }
515 }
516 closedir(d);
517 return size;
518 }
519
GetTreeBytes(const std::string & path)520 uint64_t GetTreeBytes(const std::string& path) {
521 int dirfd = open(path.c_str(), O_RDONLY | O_DIRECTORY | O_CLOEXEC);
522 if (dirfd < 0) {
523 PLOG(WARNING) << "Failed to open " << path;
524 return -1;
525 } else {
526 uint64_t res = calculate_dir_size(dirfd);
527 close(dirfd);
528 return res;
529 }
530 }
531
IsFilesystemSupported(const std::string & fsType)532 bool IsFilesystemSupported(const std::string& fsType) {
533 std::string supported;
534 if (!ReadFileToString(kProcFilesystems, &supported)) {
535 PLOG(ERROR) << "Failed to read supported filesystems";
536 return false;
537 }
538 return supported.find(fsType + "\n") != std::string::npos;
539 }
540
WipeBlockDevice(const std::string & path)541 status_t WipeBlockDevice(const std::string& path) {
542 status_t res = -1;
543 const char* c_path = path.c_str();
544 unsigned long nr_sec = 0;
545 unsigned long long range[2];
546
547 int fd = TEMP_FAILURE_RETRY(open(c_path, O_RDWR | O_CLOEXEC));
548 if (fd == -1) {
549 PLOG(ERROR) << "Failed to open " << path;
550 goto done;
551 }
552
553 if ((ioctl(fd, BLKGETSIZE, &nr_sec)) == -1) {
554 PLOG(ERROR) << "Failed to determine size of " << path;
555 goto done;
556 }
557
558 range[0] = 0;
559 range[1] = (unsigned long long) nr_sec * 512;
560
561 LOG(INFO) << "About to discard " << range[1] << " on " << path;
562 if (ioctl(fd, BLKDISCARD, &range) == 0) {
563 LOG(INFO) << "Discard success on " << path;
564 res = 0;
565 } else {
566 PLOG(ERROR) << "Discard failure on " << path;
567 }
568
569 done:
570 close(fd);
571 return res;
572 }
573
isValidFilename(const std::string & name)574 static bool isValidFilename(const std::string& name) {
575 if (name.empty() || (name == ".") || (name == "..")
576 || (name.find('/') != std::string::npos)) {
577 return false;
578 } else {
579 return true;
580 }
581 }
582
BuildKeyPath(const std::string & partGuid)583 std::string BuildKeyPath(const std::string& partGuid) {
584 return StringPrintf("%s/expand_%s.key", kKeyPath, partGuid.c_str());
585 }
586
BuildDataSystemLegacyPath(userid_t userId)587 std::string BuildDataSystemLegacyPath(userid_t userId) {
588 return StringPrintf("%s/system/users/%u", BuildDataPath(nullptr).c_str(), userId);
589 }
590
BuildDataSystemCePath(userid_t userId)591 std::string BuildDataSystemCePath(userid_t userId) {
592 return StringPrintf("%s/system_ce/%u", BuildDataPath(nullptr).c_str(), userId);
593 }
594
BuildDataSystemDePath(userid_t userId)595 std::string BuildDataSystemDePath(userid_t userId) {
596 return StringPrintf("%s/system_de/%u", BuildDataPath(nullptr).c_str(), userId);
597 }
598
BuildDataMiscLegacyPath(userid_t userId)599 std::string BuildDataMiscLegacyPath(userid_t userId) {
600 return StringPrintf("%s/misc/user/%u", BuildDataPath(nullptr).c_str(), userId);
601 }
602
BuildDataMiscCePath(userid_t userId)603 std::string BuildDataMiscCePath(userid_t userId) {
604 return StringPrintf("%s/misc_ce/%u", BuildDataPath(nullptr).c_str(), userId);
605 }
606
BuildDataMiscDePath(userid_t userId)607 std::string BuildDataMiscDePath(userid_t userId) {
608 return StringPrintf("%s/misc_de/%u", BuildDataPath(nullptr).c_str(), userId);
609 }
610
611 // Keep in sync with installd (frameworks/native/cmds/installd/utils.h)
BuildDataProfilesDePath(userid_t userId)612 std::string BuildDataProfilesDePath(userid_t userId) {
613 return StringPrintf("%s/misc/profiles/cur/%u", BuildDataPath(nullptr).c_str(), userId);
614 }
615
BuildDataPath(const char * volumeUuid)616 std::string BuildDataPath(const char* volumeUuid) {
617 // TODO: unify with installd path generation logic
618 if (volumeUuid == nullptr) {
619 return "/data";
620 } else {
621 CHECK(isValidFilename(volumeUuid));
622 return StringPrintf("/mnt/expand/%s", volumeUuid);
623 }
624 }
625
BuildDataMediaCePath(const char * volumeUuid,userid_t userId)626 std::string BuildDataMediaCePath(const char* volumeUuid, userid_t userId) {
627 // TODO: unify with installd path generation logic
628 std::string data(BuildDataPath(volumeUuid));
629 return StringPrintf("%s/media/%u", data.c_str(), userId);
630 }
631
BuildDataUserCePath(const char * volumeUuid,userid_t userId)632 std::string BuildDataUserCePath(const char* volumeUuid, userid_t userId) {
633 // TODO: unify with installd path generation logic
634 std::string data(BuildDataPath(volumeUuid));
635 if (volumeUuid == nullptr && userId == 0) {
636 std::string legacy = StringPrintf("%s/data", data.c_str());
637 struct stat sb;
638 if (lstat(legacy.c_str(), &sb) == 0 && S_ISDIR(sb.st_mode)) {
639 /* /data/data is dir, return /data/data for legacy system */
640 return legacy;
641 }
642 }
643 return StringPrintf("%s/user/%u", data.c_str(), userId);
644 }
645
BuildDataUserDePath(const char * volumeUuid,userid_t userId)646 std::string BuildDataUserDePath(const char* volumeUuid, userid_t userId) {
647 // TODO: unify with installd path generation logic
648 std::string data(BuildDataPath(volumeUuid));
649 return StringPrintf("%s/user_de/%u", data.c_str(), userId);
650 }
651
GetDevice(const std::string & path)652 dev_t GetDevice(const std::string& path) {
653 struct stat sb;
654 if (stat(path.c_str(), &sb)) {
655 PLOG(WARNING) << "Failed to stat " << path;
656 return 0;
657 } else {
658 return sb.st_dev;
659 }
660 }
661
RestoreconRecursive(const std::string & path)662 status_t RestoreconRecursive(const std::string& path) {
663 LOG(VERBOSE) << "Starting restorecon of " << path;
664
665 static constexpr const char* kRestoreconString = "selinux.restorecon_recursive";
666
667 android::base::SetProperty(kRestoreconString, "");
668 android::base::SetProperty(kRestoreconString, path);
669
670 android::base::WaitForProperty(kRestoreconString, path);
671
672 LOG(VERBOSE) << "Finished restorecon of " << path;
673 return OK;
674 }
675
SaneReadLinkAt(int dirfd,const char * path,char * buf,size_t bufsiz)676 status_t SaneReadLinkAt(int dirfd, const char* path, char* buf, size_t bufsiz) {
677 ssize_t len = readlinkat(dirfd, path, buf, bufsiz);
678 if (len < 0) {
679 return -1;
680 } else if (len == (ssize_t) bufsiz) {
681 return -1;
682 } else {
683 buf[len] = '\0';
684 return 0;
685 }
686 }
687
IsRunningInEmulator()688 bool IsRunningInEmulator() {
689 return android::base::GetBoolProperty("ro.kernel.qemu", false);
690 }
691
692 } // namespace vold
693 } // namespace android
694