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 "Disk.h" 18 #include "PublicVolume.h" 19 #include "PrivateVolume.h" 20 #include "Utils.h" 21 #include "VolumeBase.h" 22 #include "VolumeManager.h" 23 #include "Ext4Crypt.h" 24 25 #include <android-base/file.h> 26 #include <android-base/logging.h> 27 #include <android-base/properties.h> 28 #include <android-base/stringprintf.h> 29 #include <android-base/strings.h> 30 #include <android-base/parseint.h> 31 #include <ext4_utils/ext4_crypt.h> 32 33 #include "cryptfs.h" 34 35 #include <vector> 36 #include <fcntl.h> 37 #include <inttypes.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <sys/types.h> 41 #include <sys/stat.h> 42 #include <sys/sysmacros.h> 43 #include <sys/mount.h> 44 45 using android::base::ReadFileToString; 46 using android::base::WriteStringToFile; 47 using android::base::StringPrintf; 48 49 namespace android { 50 namespace vold { 51 52 static const char* kSgdiskPath = "/system/bin/sgdisk"; 53 static const char* kSgdiskToken = " \t\n"; 54 55 static const char* kSysfsLoopMaxMinors = "/sys/module/loop/parameters/max_part"; 56 static const char* kSysfsMmcMaxMinorsDeprecated = "/sys/module/mmcblk/parameters/perdev_minors"; 57 static const char* kSysfsMmcMaxMinors = "/sys/module/mmc_block/parameters/perdev_minors"; 58 59 static const unsigned int kMajorBlockLoop = 7; 60 static const unsigned int kMajorBlockScsiA = 8; 61 static const unsigned int kMajorBlockScsiB = 65; 62 static const unsigned int kMajorBlockScsiC = 66; 63 static const unsigned int kMajorBlockScsiD = 67; 64 static const unsigned int kMajorBlockScsiE = 68; 65 static const unsigned int kMajorBlockScsiF = 69; 66 static const unsigned int kMajorBlockScsiG = 70; 67 static const unsigned int kMajorBlockScsiH = 71; 68 static const unsigned int kMajorBlockScsiI = 128; 69 static const unsigned int kMajorBlockScsiJ = 129; 70 static const unsigned int kMajorBlockScsiK = 130; 71 static const unsigned int kMajorBlockScsiL = 131; 72 static const unsigned int kMajorBlockScsiM = 132; 73 static const unsigned int kMajorBlockScsiN = 133; 74 static const unsigned int kMajorBlockScsiO = 134; 75 static const unsigned int kMajorBlockScsiP = 135; 76 static const unsigned int kMajorBlockMmc = 179; 77 static const unsigned int kMajorBlockExperimentalMin = 240; 78 static const unsigned int kMajorBlockExperimentalMax = 254; 79 80 static const char* kGptBasicData = "EBD0A0A2-B9E5-4433-87C0-68B6B72699C7"; 81 static const char* kGptAndroidMeta = "19A710A2-B3CA-11E4-B026-10604B889DCF"; 82 static const char* kGptAndroidExpand = "193D1EA4-B3CA-11E4-B075-10604B889DCF"; 83 84 enum class Table { 85 kUnknown, 86 kMbr, 87 kGpt, 88 }; 89 90 static bool isVirtioBlkDevice(unsigned int major) { 91 /* 92 * The new emulator's "ranchu" virtual board no longer includes a goldfish 93 * MMC-based SD card device; instead, it emulates SD cards with virtio-blk, 94 * which has been supported by upstream kernel and QEMU for quite a while. 95 * Unfortunately, the virtio-blk block device driver does not use a fixed 96 * major number, but relies on the kernel to assign one from a specific 97 * range of block majors, which are allocated for "LOCAL/EXPERIMENAL USE" 98 * per Documentation/devices.txt. This is true even for the latest Linux 99 * kernel (4.4; see init() in drivers/block/virtio_blk.c). 100 * 101 * This makes it difficult for vold to detect a virtio-blk based SD card. 102 * The current solution checks two conditions (both must be met): 103 * 104 * a) If the running environment is the emulator; 105 * b) If the major number is an experimental block device major number (for 106 * x86/x86_64 3.10 ranchu kernels, virtio-blk always gets major number 107 * 253, but it is safer to match the range than just one value). 108 * 109 * Other conditions could be used, too, e.g. the hardware name should be 110 * "ranchu", the device's sysfs path should end with "/block/vd[d-z]", etc. 111 * But just having a) and b) is enough for now. 112 */ 113 return IsRunningInEmulator() && major >= kMajorBlockExperimentalMin 114 && major <= kMajorBlockExperimentalMax; 115 } 116 117 Disk::Disk(const std::string& eventPath, dev_t device, 118 const std::string& nickname, int flags) : 119 mDevice(device), mSize(-1), mNickname(nickname), mFlags(flags), mCreated( 120 false), mJustPartitioned(false) { 121 mId = StringPrintf("disk:%u,%u", major(device), minor(device)); 122 mEventPath = eventPath; 123 mSysPath = StringPrintf("/sys/%s", eventPath.c_str()); 124 mDevPath = StringPrintf("/dev/block/vold/%s", mId.c_str()); 125 CreateDeviceNode(mDevPath, mDevice); 126 } 127 128 Disk::~Disk() { 129 CHECK(!mCreated); 130 DestroyDeviceNode(mDevPath); 131 } 132 133 std::shared_ptr<VolumeBase> Disk::findVolume(const std::string& id) { 134 for (auto vol : mVolumes) { 135 if (vol->getId() == id) { 136 return vol; 137 } 138 auto stackedVol = vol->findVolume(id); 139 if (stackedVol != nullptr) { 140 return stackedVol; 141 } 142 } 143 return nullptr; 144 } 145 146 void Disk::listVolumes(VolumeBase::Type type, std::list<std::string>& list) { 147 for (const auto& vol : mVolumes) { 148 if (vol->getType() == type) { 149 list.push_back(vol->getId()); 150 } 151 // TODO: consider looking at stacked volumes 152 } 153 } 154 155 status_t Disk::create() { 156 CHECK(!mCreated); 157 mCreated = true; 158 159 auto listener = VolumeManager::Instance()->getListener(); 160 if (listener) listener->onDiskCreated(getId(), mFlags); 161 162 readMetadata(); 163 readPartitions(); 164 return OK; 165 } 166 167 status_t Disk::destroy() { 168 CHECK(mCreated); 169 destroyAllVolumes(); 170 mCreated = false; 171 172 auto listener = VolumeManager::Instance()->getListener(); 173 if (listener) listener->onDiskDestroyed(getId()); 174 175 return OK; 176 } 177 178 void Disk::createPublicVolume(dev_t device) { 179 auto vol = std::shared_ptr<VolumeBase>(new PublicVolume(device)); 180 if (mJustPartitioned) { 181 LOG(DEBUG) << "Device just partitioned; silently formatting"; 182 vol->setSilent(true); 183 vol->create(); 184 vol->format("auto"); 185 vol->destroy(); 186 vol->setSilent(false); 187 } 188 189 mVolumes.push_back(vol); 190 vol->setDiskId(getId()); 191 vol->create(); 192 } 193 194 void Disk::createPrivateVolume(dev_t device, const std::string& partGuid) { 195 std::string normalizedGuid; 196 if (NormalizeHex(partGuid, normalizedGuid)) { 197 LOG(WARNING) << "Invalid GUID " << partGuid; 198 return; 199 } 200 201 std::string keyRaw; 202 if (!ReadFileToString(BuildKeyPath(normalizedGuid), &keyRaw)) { 203 PLOG(ERROR) << "Failed to load key for GUID " << normalizedGuid; 204 return; 205 } 206 207 LOG(DEBUG) << "Found key for GUID " << normalizedGuid; 208 209 auto vol = std::shared_ptr<VolumeBase>(new PrivateVolume(device, keyRaw)); 210 if (mJustPartitioned) { 211 LOG(DEBUG) << "Device just partitioned; silently formatting"; 212 vol->setSilent(true); 213 vol->create(); 214 vol->format("auto"); 215 vol->destroy(); 216 vol->setSilent(false); 217 } 218 219 mVolumes.push_back(vol); 220 vol->setDiskId(getId()); 221 vol->setPartGuid(partGuid); 222 vol->create(); 223 } 224 225 void Disk::destroyAllVolumes() { 226 for (const auto& vol : mVolumes) { 227 vol->destroy(); 228 } 229 mVolumes.clear(); 230 } 231 232 status_t Disk::readMetadata() { 233 mSize = -1; 234 mLabel.clear(); 235 236 int fd = open(mDevPath.c_str(), O_RDONLY | O_CLOEXEC); 237 if (fd != -1) { 238 if (ioctl(fd, BLKGETSIZE64, &mSize)) { 239 mSize = -1; 240 } 241 close(fd); 242 } 243 244 unsigned int majorId = major(mDevice); 245 switch (majorId) { 246 case kMajorBlockLoop: { 247 mLabel = "Virtual"; 248 break; 249 } 250 case kMajorBlockScsiA: case kMajorBlockScsiB: case kMajorBlockScsiC: case kMajorBlockScsiD: 251 case kMajorBlockScsiE: case kMajorBlockScsiF: case kMajorBlockScsiG: case kMajorBlockScsiH: 252 case kMajorBlockScsiI: case kMajorBlockScsiJ: case kMajorBlockScsiK: case kMajorBlockScsiL: 253 case kMajorBlockScsiM: case kMajorBlockScsiN: case kMajorBlockScsiO: case kMajorBlockScsiP: { 254 std::string path(mSysPath + "/device/vendor"); 255 std::string tmp; 256 if (!ReadFileToString(path, &tmp)) { 257 PLOG(WARNING) << "Failed to read vendor from " << path; 258 return -errno; 259 } 260 tmp = android::base::Trim(tmp); 261 mLabel = tmp; 262 break; 263 } 264 case kMajorBlockMmc: { 265 std::string path(mSysPath + "/device/manfid"); 266 std::string tmp; 267 if (!ReadFileToString(path, &tmp)) { 268 PLOG(WARNING) << "Failed to read manufacturer from " << path; 269 return -errno; 270 } 271 tmp = android::base::Trim(tmp); 272 int64_t manfid; 273 if (!android::base::ParseInt(tmp, &manfid)) { 274 PLOG(WARNING) << "Failed to parse manufacturer " << tmp; 275 return -EINVAL; 276 } 277 // Our goal here is to give the user a meaningful label, ideally 278 // matching whatever is silk-screened on the card. To reduce 279 // user confusion, this list doesn't contain white-label manfid. 280 switch (manfid) { 281 case 0x000003: mLabel = "SanDisk"; break; 282 case 0x00001b: mLabel = "Samsung"; break; 283 case 0x000028: mLabel = "Lexar"; break; 284 case 0x000074: mLabel = "Transcend"; break; 285 } 286 break; 287 } 288 default: { 289 if (isVirtioBlkDevice(majorId)) { 290 LOG(DEBUG) << "Recognized experimental block major ID " << majorId 291 << " as virtio-blk (emulator's virtual SD card device)"; 292 mLabel = "Virtual"; 293 break; 294 } 295 LOG(WARNING) << "Unsupported block major type " << majorId; 296 return -ENOTSUP; 297 } 298 } 299 300 auto listener = VolumeManager::Instance()->getListener(); 301 if (listener) listener->onDiskMetadataChanged(getId(), 302 mSize, mLabel, mSysPath); 303 304 return OK; 305 } 306 307 status_t Disk::readPartitions() { 308 int maxMinors = getMaxMinors(); 309 if (maxMinors < 0) { 310 return -ENOTSUP; 311 } 312 313 destroyAllVolumes(); 314 315 // Parse partition table 316 317 std::vector<std::string> cmd; 318 cmd.push_back(kSgdiskPath); 319 cmd.push_back("--android-dump"); 320 cmd.push_back(mDevPath); 321 322 std::vector<std::string> output; 323 status_t res = ForkExecvp(cmd, output); 324 if (res != OK) { 325 LOG(WARNING) << "sgdisk failed to scan " << mDevPath; 326 327 auto listener = VolumeManager::Instance()->getListener(); 328 if (listener) listener->onDiskScanned(getId()); 329 330 mJustPartitioned = false; 331 return res; 332 } 333 334 Table table = Table::kUnknown; 335 bool foundParts = false; 336 for (const auto& line : output) { 337 auto split = android::base::Split(line, kSgdiskToken); 338 auto it = split.begin(); 339 if (it == split.end()) continue; 340 341 if (*it == "DISK") { 342 if (++it == split.end()) continue; 343 if (*it == "mbr") { 344 table = Table::kMbr; 345 } else if (*it == "gpt") { 346 table = Table::kGpt; 347 } else { 348 LOG(WARNING) << "Invalid partition table " << *it; 349 continue; 350 } 351 } else if (*it == "PART") { 352 foundParts = true; 353 354 if (++it == split.end()) continue; 355 int i = 0; 356 if (!android::base::ParseInt(*it, &i, 1, maxMinors)) { 357 LOG(WARNING) << "Invalid partition number " << *it; 358 continue; 359 } 360 dev_t partDevice = makedev(major(mDevice), minor(mDevice) + i); 361 362 if (table == Table::kMbr) { 363 if (++it == split.end()) continue; 364 int type = 0; 365 if (!android::base::ParseInt("0x" + *it, &type)) { 366 LOG(WARNING) << "Invalid partition type " << *it; 367 continue; 368 } 369 370 switch (type) { 371 case 0x06: // FAT16 372 case 0x07: // HPFS/NTFS/exFAT 373 case 0x0b: // W95 FAT32 (LBA) 374 case 0x0c: // W95 FAT32 (LBA) 375 case 0x0e: // W95 FAT16 (LBA) 376 createPublicVolume(partDevice); 377 break; 378 } 379 } else if (table == Table::kGpt) { 380 if (++it == split.end()) continue; 381 auto typeGuid = *it; 382 if (++it == split.end()) continue; 383 auto partGuid = *it; 384 385 if (android::base::EqualsIgnoreCase(typeGuid, kGptBasicData)) { 386 createPublicVolume(partDevice); 387 } else if (android::base::EqualsIgnoreCase(typeGuid, kGptAndroidExpand)) { 388 createPrivateVolume(partDevice, partGuid); 389 } 390 } 391 } 392 } 393 394 // Ugly last ditch effort, treat entire disk as partition 395 if (table == Table::kUnknown || !foundParts) { 396 LOG(WARNING) << mId << " has unknown partition table; trying entire device"; 397 398 std::string fsType; 399 std::string unused; 400 if (ReadMetadataUntrusted(mDevPath, &fsType, &unused, &unused) == OK) { 401 createPublicVolume(mDevice); 402 } else { 403 LOG(WARNING) << mId << " failed to identify, giving up"; 404 } 405 } 406 407 auto listener = VolumeManager::Instance()->getListener(); 408 if (listener) listener->onDiskScanned(getId()); 409 410 mJustPartitioned = false; 411 return OK; 412 } 413 414 status_t Disk::unmountAll() { 415 for (const auto& vol : mVolumes) { 416 vol->unmount(); 417 } 418 return OK; 419 } 420 421 status_t Disk::partitionPublic() { 422 int res; 423 424 destroyAllVolumes(); 425 mJustPartitioned = true; 426 427 // First nuke any existing partition table 428 std::vector<std::string> cmd; 429 cmd.push_back(kSgdiskPath); 430 cmd.push_back("--zap-all"); 431 cmd.push_back(mDevPath); 432 433 // Zap sometimes returns an error when it actually succeeded, so 434 // just log as warning and keep rolling forward. 435 if ((res = ForkExecvp(cmd)) != 0) { 436 LOG(WARNING) << "Failed to zap; status " << res; 437 } 438 439 // Now let's build the new MBR table. We heavily rely on sgdisk to 440 // force optimal alignment on the created partitions. 441 cmd.clear(); 442 cmd.push_back(kSgdiskPath); 443 cmd.push_back("--new=0:0:-0"); 444 cmd.push_back("--typecode=0:0c00"); 445 cmd.push_back("--gpttombr=1"); 446 cmd.push_back(mDevPath); 447 448 if ((res = ForkExecvp(cmd)) != 0) { 449 LOG(ERROR) << "Failed to partition; status " << res; 450 return res; 451 } 452 453 return OK; 454 } 455 456 status_t Disk::partitionPrivate() { 457 return partitionMixed(0); 458 } 459 460 status_t Disk::partitionMixed(int8_t ratio) { 461 int res; 462 463 destroyAllVolumes(); 464 mJustPartitioned = true; 465 466 // First nuke any existing partition table 467 std::vector<std::string> cmd; 468 cmd.push_back(kSgdiskPath); 469 cmd.push_back("--zap-all"); 470 cmd.push_back(mDevPath); 471 472 // Zap sometimes returns an error when it actually succeeded, so 473 // just log as warning and keep rolling forward. 474 if ((res = ForkExecvp(cmd)) != 0) { 475 LOG(WARNING) << "Failed to zap; status " << res; 476 } 477 478 // We've had some success above, so generate both the private partition 479 // GUID and encryption key and persist them. 480 std::string partGuidRaw; 481 if (GenerateRandomUuid(partGuidRaw) != OK) { 482 LOG(ERROR) << "Failed to generate GUID"; 483 return -EIO; 484 } 485 486 std::string keyRaw; 487 if (ReadRandomBytes(cryptfs_get_keysize(), keyRaw) != OK) { 488 LOG(ERROR) << "Failed to generate key"; 489 return -EIO; 490 } 491 492 std::string partGuid; 493 StrToHex(partGuidRaw, partGuid); 494 495 if (!WriteStringToFile(keyRaw, BuildKeyPath(partGuid))) { 496 LOG(ERROR) << "Failed to persist key"; 497 return -EIO; 498 } else { 499 LOG(DEBUG) << "Persisted key for GUID " << partGuid; 500 } 501 502 // Now let's build the new GPT table. We heavily rely on sgdisk to 503 // force optimal alignment on the created partitions. 504 cmd.clear(); 505 cmd.push_back(kSgdiskPath); 506 507 // If requested, create a public partition first. Mixed-mode partitioning 508 // like this is an experimental feature. 509 if (ratio > 0) { 510 if (ratio < 10 || ratio > 90) { 511 LOG(ERROR) << "Mixed partition ratio must be between 10-90%"; 512 return -EINVAL; 513 } 514 515 uint64_t splitMb = ((mSize / 100) * ratio) / 1024 / 1024; 516 cmd.push_back(StringPrintf("--new=0:0:+%" PRId64 "M", splitMb)); 517 cmd.push_back(StringPrintf("--typecode=0:%s", kGptBasicData)); 518 cmd.push_back("--change-name=0:shared"); 519 } 520 521 // Define a metadata partition which is designed for future use; there 522 // should only be one of these per physical device, even if there are 523 // multiple private volumes. 524 cmd.push_back("--new=0:0:+16M"); 525 cmd.push_back(StringPrintf("--typecode=0:%s", kGptAndroidMeta)); 526 cmd.push_back("--change-name=0:android_meta"); 527 528 // Define a single private partition filling the rest of disk. 529 cmd.push_back("--new=0:0:-0"); 530 cmd.push_back(StringPrintf("--typecode=0:%s", kGptAndroidExpand)); 531 cmd.push_back(StringPrintf("--partition-guid=0:%s", partGuid.c_str())); 532 cmd.push_back("--change-name=0:android_expand"); 533 534 cmd.push_back(mDevPath); 535 536 if ((res = ForkExecvp(cmd)) != 0) { 537 LOG(ERROR) << "Failed to partition; status " << res; 538 return res; 539 } 540 541 return OK; 542 } 543 544 int Disk::getMaxMinors() { 545 // Figure out maximum partition devices supported 546 unsigned int majorId = major(mDevice); 547 switch (majorId) { 548 case kMajorBlockLoop: { 549 std::string tmp; 550 if (!ReadFileToString(kSysfsLoopMaxMinors, &tmp)) { 551 LOG(ERROR) << "Failed to read max minors"; 552 return -errno; 553 } 554 return std::stoi(tmp); 555 } 556 case kMajorBlockScsiA: case kMajorBlockScsiB: case kMajorBlockScsiC: case kMajorBlockScsiD: 557 case kMajorBlockScsiE: case kMajorBlockScsiF: case kMajorBlockScsiG: case kMajorBlockScsiH: 558 case kMajorBlockScsiI: case kMajorBlockScsiJ: case kMajorBlockScsiK: case kMajorBlockScsiL: 559 case kMajorBlockScsiM: case kMajorBlockScsiN: case kMajorBlockScsiO: case kMajorBlockScsiP: { 560 // Per Documentation/devices.txt this is static 561 return 15; 562 } 563 case kMajorBlockMmc: { 564 // Per Documentation/devices.txt this is dynamic 565 std::string tmp; 566 if (!ReadFileToString(kSysfsMmcMaxMinors, &tmp) && 567 !ReadFileToString(kSysfsMmcMaxMinorsDeprecated, &tmp)) { 568 LOG(ERROR) << "Failed to read max minors"; 569 return -errno; 570 } 571 return std::stoi(tmp); 572 } 573 default: { 574 if (isVirtioBlkDevice(majorId)) { 575 // drivers/block/virtio_blk.c has "#define PART_BITS 4", so max is 576 // 2^4 - 1 = 15 577 return 15; 578 } 579 } 580 } 581 582 LOG(ERROR) << "Unsupported block major type " << majorId; 583 return -ENOTSUP; 584 } 585 586 } // namespace vold 587 } // namespace android 588