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 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 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 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 } 122 123 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 } 152 153 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 } 178 179 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 } 186 187 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 } 234 235 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 } 239 240 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 } 244 245 status_t ForkExecvp(const std::vector<std::string>& args) { 246 return ForkExecvp(args, nullptr); 247 } 248 249 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 } 274 275 status_t ForkExecvp(const std::vector<std::string>& args, 276 std::vector<std::string>& output) { 277 return ForkExecvp(args, output, nullptr); 278 } 279 280 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 } 319 320 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 } 352 353 status_t ReadRandomBytes(size_t bytes, std::string& out) { 354 out.resize(bytes); 355 return ReadRandomBytes(bytes, &out[0]); 356 } 357 358 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 } 377 378 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 } 388 389 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"; 429 430 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 } 438 439 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 } 447 448 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 } 455 456 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/ 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/ 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 } 519 520 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 } 531 532 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 } 540 541 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 } 573 574 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 } 582 583 std::string BuildKeyPath(const std::string& partGuid) { 584 return StringPrintf("%s/expand_%s.key", kKeyPath, partGuid.c_str()); 585 } 586 587 std::string BuildDataSystemLegacyPath(userid_t userId) { 588 return StringPrintf("%s/system/users/%u", BuildDataPath(nullptr).c_str(), userId); 589 } 590 591 std::string BuildDataSystemCePath(userid_t userId) { 592 return StringPrintf("%s/system_ce/%u", BuildDataPath(nullptr).c_str(), userId); 593 } 594 595 std::string BuildDataSystemDePath(userid_t userId) { 596 return StringPrintf("%s/system_de/%u", BuildDataPath(nullptr).c_str(), userId); 597 } 598 599 std::string BuildDataMiscLegacyPath(userid_t userId) { 600 return StringPrintf("%s/misc/user/%u", BuildDataPath(nullptr).c_str(), userId); 601 } 602 603 std::string BuildDataMiscCePath(userid_t userId) { 604 return StringPrintf("%s/misc_ce/%u", BuildDataPath(nullptr).c_str(), userId); 605 } 606 607 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) 612 std::string BuildDataProfilesDePath(userid_t userId) { 613 return StringPrintf("%s/misc/profiles/cur/%u", BuildDataPath(nullptr).c_str(), userId); 614 } 615 616 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 } 625 626 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 } 631 632 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 } 645 646 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 } 651 652 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 } 661 662 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 } 675 676 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 } 687 688 bool IsRunningInEmulator() { 689 return android::base::GetBoolProperty("ro.kernel.qemu", false); 690 } 691 692 } // namespace vold 693 } // namespace android 694
