Disk.cpp revision 11c2d380a786d9e304416be98881b90b74ff666d 
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 "ResponseCode.h"
24#include "Ext4Crypt.h"
25
26#include <android-base/file.h>
27#include <android-base/properties.h>
28#include <android-base/stringprintf.h>
29#include <android-base/logging.h>
30#include <diskconfig/diskconfig.h>
31
32#include <vector>
33#include <fcntl.h>
34#include <inttypes.h>
35#include <stdio.h>
36#include <stdlib.h>
37#include <sys/types.h>
38#include <sys/stat.h>
39#include <sys/sysmacros.h>
40#include <sys/mount.h>
41
42using android::base::ReadFileToString;
43using android::base::WriteStringToFile;
44using android::base::StringPrintf;
45
46namespace android {
47namespace vold {
48
49static const char* kSgdiskPath = "/system/bin/sgdisk";
50static const char* kSgdiskToken = " \t\n";
51
52static const char* kSysfsLoopMaxMinors = "/sys/module/loop/parameters/max_part";
53static const char* kSysfsMmcMaxMinors = "/sys/module/mmcblk/parameters/perdev_minors";
54
55static const unsigned int kMajorBlockLoop = 7;
56static const unsigned int kMajorBlockScsiA = 8;
57static const unsigned int kMajorBlockScsiB = 65;
58static const unsigned int kMajorBlockScsiC = 66;
59static const unsigned int kMajorBlockScsiD = 67;
60static const unsigned int kMajorBlockScsiE = 68;
61static const unsigned int kMajorBlockScsiF = 69;
62static const unsigned int kMajorBlockScsiG = 70;
63static const unsigned int kMajorBlockScsiH = 71;
64static const unsigned int kMajorBlockScsiI = 128;
65static const unsigned int kMajorBlockScsiJ = 129;
66static const unsigned int kMajorBlockScsiK = 130;
67static const unsigned int kMajorBlockScsiL = 131;
68static const unsigned int kMajorBlockScsiM = 132;
69static const unsigned int kMajorBlockScsiN = 133;
70static const unsigned int kMajorBlockScsiO = 134;
71static const unsigned int kMajorBlockScsiP = 135;
72static const unsigned int kMajorBlockMmc = 179;
73static const unsigned int kMajorBlockExperimentalMin = 240;
74static const unsigned int kMajorBlockExperimentalMax = 254;
75
76static const char* kGptBasicData = "EBD0A0A2-B9E5-4433-87C0-68B6B72699C7";
77static const char* kGptAndroidMeta = "19A710A2-B3CA-11E4-B026-10604B889DCF";
78static const char* kGptAndroidExpand = "193D1EA4-B3CA-11E4-B075-10604B889DCF";
79
80enum class Table {
81    kUnknown,
82    kMbr,
83    kGpt,
84};
85
86static bool isVirtioBlkDevice(unsigned int major) {
87    /*
88     * The new emulator's "ranchu" virtual board no longer includes a goldfish
89     * MMC-based SD card device; instead, it emulates SD cards with virtio-blk,
90     * which has been supported by upstream kernel and QEMU for quite a while.
91     * Unfortunately, the virtio-blk block device driver does not use a fixed
92     * major number, but relies on the kernel to assign one from a specific
93     * range of block majors, which are allocated for "LOCAL/EXPERIMENAL USE"
94     * per Documentation/devices.txt. This is true even for the latest Linux
95     * kernel (4.4; see init() in drivers/block/virtio_blk.c).
96     *
97     * This makes it difficult for vold to detect a virtio-blk based SD card.
98     * The current solution checks two conditions (both must be met):
99     *
100     *  a) If the running environment is the emulator;
101     *  b) If the major number is an experimental block device major number (for
102     *     x86/x86_64 3.10 ranchu kernels, virtio-blk always gets major number
103     *     253, but it is safer to match the range than just one value).
104     *
105     * Other conditions could be used, too, e.g. the hardware name should be
106     * "ranchu", the device's sysfs path should end with "/block/vd[d-z]", etc.
107     * But just having a) and b) is enough for now.
108     */
109    return IsRunningInEmulator() && major >= kMajorBlockExperimentalMin
110            && major <= kMajorBlockExperimentalMax;
111}
112
113Disk::Disk(const std::string& eventPath, dev_t device,
114        const std::string& nickname, int flags) :
115        mDevice(device), mSize(-1), mNickname(nickname), mFlags(flags), mCreated(
116                false), mJustPartitioned(false) {
117    mId = StringPrintf("disk:%u,%u", major(device), minor(device));
118    mEventPath = eventPath;
119    mSysPath = StringPrintf("/sys/%s", eventPath.c_str());
120    mDevPath = StringPrintf("/dev/block/vold/%s", mId.c_str());
121    CreateDeviceNode(mDevPath, mDevice);
122}
123
124Disk::~Disk() {
125    CHECK(!mCreated);
126    DestroyDeviceNode(mDevPath);
127}
128
129std::shared_ptr<VolumeBase> Disk::findVolume(const std::string& id) {
130    for (auto vol : mVolumes) {
131        if (vol->getId() == id) {
132            return vol;
133        }
134        auto stackedVol = vol->findVolume(id);
135        if (stackedVol != nullptr) {
136            return stackedVol;
137        }
138    }
139    return nullptr;
140}
141
142void Disk::listVolumes(VolumeBase::Type type, std::list<std::string>& list) {
143    for (const auto& vol : mVolumes) {
144        if (vol->getType() == type) {
145            list.push_back(vol->getId());
146        }
147        // TODO: consider looking at stacked volumes
148    }
149}
150
151status_t Disk::create() {
152    CHECK(!mCreated);
153    mCreated = true;
154    notifyEvent(ResponseCode::DiskCreated, StringPrintf("%d", mFlags));
155    readMetadata();
156    readPartitions();
157    return OK;
158}
159
160status_t Disk::destroy() {
161    CHECK(mCreated);
162    destroyAllVolumes();
163    mCreated = false;
164    notifyEvent(ResponseCode::DiskDestroyed);
165    return OK;
166}
167
168void Disk::createPublicVolume(dev_t device) {
169    auto vol = std::shared_ptr<VolumeBase>(new PublicVolume(device));
170    if (mJustPartitioned) {
171        LOG(DEBUG) << "Device just partitioned; silently formatting";
172        vol->setSilent(true);
173        vol->create();
174        vol->format("auto");
175        vol->destroy();
176        vol->setSilent(false);
177    }
178
179    mVolumes.push_back(vol);
180    vol->setDiskId(getId());
181    vol->create();
182}
183
184void Disk::createPrivateVolume(dev_t device, const std::string& partGuid) {
185    std::string normalizedGuid;
186    if (NormalizeHex(partGuid, normalizedGuid)) {
187        LOG(WARNING) << "Invalid GUID " << partGuid;
188        return;
189    }
190
191    std::string keyRaw;
192    if (!ReadFileToString(BuildKeyPath(normalizedGuid), &keyRaw)) {
193        PLOG(ERROR) << "Failed to load key for GUID " << normalizedGuid;
194        return;
195    }
196
197    LOG(DEBUG) << "Found key for GUID " << normalizedGuid;
198
199    auto vol = std::shared_ptr<VolumeBase>(new PrivateVolume(device, keyRaw));
200    if (mJustPartitioned) {
201        LOG(DEBUG) << "Device just partitioned; silently formatting";
202        vol->setSilent(true);
203        vol->create();
204        vol->format("auto");
205        vol->destroy();
206        vol->setSilent(false);
207    }
208
209    mVolumes.push_back(vol);
210    vol->setDiskId(getId());
211    vol->setPartGuid(partGuid);
212    vol->create();
213}
214
215void Disk::destroyAllVolumes() {
216    for (const auto& vol : mVolumes) {
217        vol->destroy();
218    }
219    mVolumes.clear();
220}
221
222status_t Disk::readMetadata() {
223    mSize = -1;
224    mLabel.clear();
225
226    int fd = open(mDevPath.c_str(), O_RDONLY | O_CLOEXEC);
227    if (fd != -1) {
228        if (ioctl(fd, BLKGETSIZE64, &mSize)) {
229            mSize = -1;
230        }
231        close(fd);
232    }
233
234    unsigned int majorId = major(mDevice);
235    switch (majorId) {
236    case kMajorBlockLoop: {
237        mLabel = "Virtual";
238        break;
239    }
240    case kMajorBlockScsiA: case kMajorBlockScsiB: case kMajorBlockScsiC: case kMajorBlockScsiD:
241    case kMajorBlockScsiE: case kMajorBlockScsiF: case kMajorBlockScsiG: case kMajorBlockScsiH:
242    case kMajorBlockScsiI: case kMajorBlockScsiJ: case kMajorBlockScsiK: case kMajorBlockScsiL:
243    case kMajorBlockScsiM: case kMajorBlockScsiN: case kMajorBlockScsiO: case kMajorBlockScsiP: {
244        std::string path(mSysPath + "/device/vendor");
245        std::string tmp;
246        if (!ReadFileToString(path, &tmp)) {
247            PLOG(WARNING) << "Failed to read vendor from " << path;
248            return -errno;
249        }
250        mLabel = tmp;
251        break;
252    }
253    case kMajorBlockMmc: {
254        std::string path(mSysPath + "/device/manfid");
255        std::string tmp;
256        if (!ReadFileToString(path, &tmp)) {
257            PLOG(WARNING) << "Failed to read manufacturer from " << path;
258            return -errno;
259        }
260        uint64_t manfid = strtoll(tmp.c_str(), nullptr, 16);
261        // Our goal here is to give the user a meaningful label, ideally
262        // matching whatever is silk-screened on the card.  To reduce
263        // user confusion, this list doesn't contain white-label manfid.
264        switch (manfid) {
265        case 0x000003: mLabel = "SanDisk"; break;
266        case 0x00001b: mLabel = "Samsung"; break;
267        case 0x000028: mLabel = "Lexar"; break;
268        case 0x000074: mLabel = "Transcend"; break;
269        }
270        break;
271    }
272    default: {
273        if (isVirtioBlkDevice(majorId)) {
274            LOG(DEBUG) << "Recognized experimental block major ID " << majorId
275                    << " as virtio-blk (emulator's virtual SD card device)";
276            mLabel = "Virtual";
277            break;
278        }
279        LOG(WARNING) << "Unsupported block major type " << majorId;
280        return -ENOTSUP;
281    }
282    }
283
284    notifyEvent(ResponseCode::DiskSizeChanged, StringPrintf("%" PRIu64, mSize));
285    notifyEvent(ResponseCode::DiskLabelChanged, mLabel);
286    notifyEvent(ResponseCode::DiskSysPathChanged, mSysPath);
287    return OK;
288}
289
290status_t Disk::readPartitions() {
291    int8_t maxMinors = getMaxMinors();
292    if (maxMinors < 0) {
293        return -ENOTSUP;
294    }
295
296    destroyAllVolumes();
297
298    // Parse partition table
299
300    std::vector<std::string> cmd;
301    cmd.push_back(kSgdiskPath);
302    cmd.push_back("--android-dump");
303    cmd.push_back(mDevPath);
304
305    std::vector<std::string> output;
306    status_t res = ForkExecvp(cmd, output);
307    if (res != OK) {
308        LOG(WARNING) << "sgdisk failed to scan " << mDevPath;
309        notifyEvent(ResponseCode::DiskScanned);
310        mJustPartitioned = false;
311        return res;
312    }
313
314    Table table = Table::kUnknown;
315    bool foundParts = false;
316    for (const auto& line : output) {
317        char* cline = (char*) line.c_str();
318        char* token = strtok(cline, kSgdiskToken);
319        if (token == nullptr) continue;
320
321        if (!strcmp(token, "DISK")) {
322            const char* type = strtok(nullptr, kSgdiskToken);
323            if (!strcmp(type, "mbr")) {
324                table = Table::kMbr;
325            } else if (!strcmp(type, "gpt")) {
326                table = Table::kGpt;
327            }
328        } else if (!strcmp(token, "PART")) {
329            foundParts = true;
330            int i = strtol(strtok(nullptr, kSgdiskToken), nullptr, 10);
331            if (i <= 0 || i > maxMinors) {
332                LOG(WARNING) << mId << " is ignoring partition " << i
333                        << " beyond max supported devices";
334                continue;
335            }
336            dev_t partDevice = makedev(major(mDevice), minor(mDevice) + i);
337
338            if (table == Table::kMbr) {
339                const char* type = strtok(nullptr, kSgdiskToken);
340
341                switch (strtol(type, nullptr, 16)) {
342                case 0x06: // FAT16
343                case 0x0b: // W95 FAT32 (LBA)
344                case 0x0c: // W95 FAT32 (LBA)
345                case 0x0e: // W95 FAT16 (LBA)
346                    createPublicVolume(partDevice);
347                    break;
348                }
349            } else if (table == Table::kGpt) {
350                const char* typeGuid = strtok(nullptr, kSgdiskToken);
351                const char* partGuid = strtok(nullptr, kSgdiskToken);
352
353                if (!strcasecmp(typeGuid, kGptBasicData)) {
354                    createPublicVolume(partDevice);
355                } else if (!strcasecmp(typeGuid, kGptAndroidExpand)) {
356                    createPrivateVolume(partDevice, partGuid);
357                }
358            }
359        }
360    }
361
362    // Ugly last ditch effort, treat entire disk as partition
363    if (table == Table::kUnknown || !foundParts) {
364        LOG(WARNING) << mId << " has unknown partition table; trying entire device";
365
366        std::string fsType;
367        std::string unused;
368        if (ReadMetadataUntrusted(mDevPath, fsType, unused, unused) == OK) {
369            createPublicVolume(mDevice);
370        } else {
371            LOG(WARNING) << mId << " failed to identify, giving up";
372        }
373    }
374
375    notifyEvent(ResponseCode::DiskScanned);
376    mJustPartitioned = false;
377    return OK;
378}
379
380status_t Disk::unmountAll() {
381    for (const auto& vol : mVolumes) {
382        vol->unmount();
383    }
384    return OK;
385}
386
387status_t Disk::partitionPublic() {
388    int res;
389
390    // TODO: improve this code
391    destroyAllVolumes();
392    mJustPartitioned = true;
393
394    // First nuke any existing partition table
395    std::vector<std::string> cmd;
396    cmd.push_back(kSgdiskPath);
397    cmd.push_back("--zap-all");
398    cmd.push_back(mDevPath);
399
400    // Zap sometimes returns an error when it actually succeeded, so
401    // just log as warning and keep rolling forward.
402    if ((res = ForkExecvp(cmd)) != 0) {
403        LOG(WARNING) << "Failed to zap; status " << res;
404    }
405
406    struct disk_info dinfo;
407    memset(&dinfo, 0, sizeof(dinfo));
408
409    if (!(dinfo.part_lst = (struct part_info *) malloc(
410            MAX_NUM_PARTS * sizeof(struct part_info)))) {
411        return -1;
412    }
413
414    memset(dinfo.part_lst, 0, MAX_NUM_PARTS * sizeof(struct part_info));
415    dinfo.device = strdup(mDevPath.c_str());
416    dinfo.scheme = PART_SCHEME_MBR;
417    dinfo.sect_size = 512;
418    dinfo.skip_lba = 2048;
419    dinfo.num_lba = 0;
420    dinfo.num_parts = 1;
421
422    struct part_info *pinfo = &dinfo.part_lst[0];
423
424    pinfo->name = strdup("android_sdcard");
425    pinfo->flags |= PART_ACTIVE_FLAG;
426    pinfo->type = PC_PART_TYPE_FAT32;
427    pinfo->len_kb = -1;
428
429    int rc = apply_disk_config(&dinfo, 0);
430    if (rc) {
431        LOG(ERROR) << "Failed to apply disk configuration: " << rc;
432        goto out;
433    }
434
435out:
436    free(pinfo->name);
437    free(dinfo.device);
438    free(dinfo.part_lst);
439
440    return rc;
441}
442
443status_t Disk::partitionPrivate() {
444    return partitionMixed(0);
445}
446
447status_t Disk::partitionMixed(int8_t ratio) {
448    int res;
449
450    if (e4crypt_is_native()
451            && !android::base::GetBoolProperty("persist.sys.adoptable_fbe", false)) {
452        LOG(ERROR) << "Private volumes not yet supported on FBE devices";
453        return -EINVAL;
454    }
455
456    destroyAllVolumes();
457    mJustPartitioned = true;
458
459    // First nuke any existing partition table
460    std::vector<std::string> cmd;
461    cmd.push_back(kSgdiskPath);
462    cmd.push_back("--zap-all");
463    cmd.push_back(mDevPath);
464
465    // Zap sometimes returns an error when it actually succeeded, so
466    // just log as warning and keep rolling forward.
467    if ((res = ForkExecvp(cmd)) != 0) {
468        LOG(WARNING) << "Failed to zap; status " << res;
469    }
470
471    // We've had some success above, so generate both the private partition
472    // GUID and encryption key and persist them.
473    std::string partGuidRaw;
474    if (GenerateRandomUuid(partGuidRaw) != OK) {
475        LOG(ERROR) << "Failed to generate GUID";
476        return -EIO;
477    }
478
479    std::string keyRaw;
480    if (ReadRandomBytes(16, keyRaw) != OK) {
481        LOG(ERROR) << "Failed to generate key";
482        return -EIO;
483    }
484
485    std::string partGuid;
486    StrToHex(partGuidRaw, partGuid);
487
488    if (!WriteStringToFile(keyRaw, BuildKeyPath(partGuid))) {
489        LOG(ERROR) << "Failed to persist key";
490        return -EIO;
491    } else {
492        LOG(DEBUG) << "Persisted key for GUID " << partGuid;
493    }
494
495    // Now let's build the new GPT table. We heavily rely on sgdisk to
496    // force optimal alignment on the created partitions.
497    cmd.clear();
498    cmd.push_back(kSgdiskPath);
499
500    // If requested, create a public partition first. Mixed-mode partitioning
501    // like this is an experimental feature.
502    if (ratio > 0) {
503        if (ratio < 10 || ratio > 90) {
504            LOG(ERROR) << "Mixed partition ratio must be between 10-90%";
505            return -EINVAL;
506        }
507
508        uint64_t splitMb = ((mSize / 100) * ratio) / 1024 / 1024;
509        cmd.push_back(StringPrintf("--new=0:0:+%" PRId64 "M", splitMb));
510        cmd.push_back(StringPrintf("--typecode=0:%s", kGptBasicData));
511        cmd.push_back("--change-name=0:shared");
512    }
513
514    // Define a metadata partition which is designed for future use; there
515    // should only be one of these per physical device, even if there are
516    // multiple private volumes.
517    cmd.push_back("--new=0:0:+16M");
518    cmd.push_back(StringPrintf("--typecode=0:%s", kGptAndroidMeta));
519    cmd.push_back("--change-name=0:android_meta");
520
521    // Define a single private partition filling the rest of disk.
522    cmd.push_back("--new=0:0:-0");
523    cmd.push_back(StringPrintf("--typecode=0:%s", kGptAndroidExpand));
524    cmd.push_back(StringPrintf("--partition-guid=0:%s", partGuid.c_str()));
525    cmd.push_back("--change-name=0:android_expand");
526
527    cmd.push_back(mDevPath);
528
529    if ((res = ForkExecvp(cmd)) != 0) {
530        LOG(ERROR) << "Failed to partition; status " << res;
531        return res;
532    }
533
534    return OK;
535}
536
537void Disk::notifyEvent(int event) {
538    VolumeManager::Instance()->getBroadcaster()->sendBroadcast(event,
539            getId().c_str(), false);
540}
541
542void Disk::notifyEvent(int event, const std::string& value) {
543    VolumeManager::Instance()->getBroadcaster()->sendBroadcast(event,
544            StringPrintf("%s %s", getId().c_str(), value.c_str()).c_str(), false);
545}
546
547int Disk::getMaxMinors() {
548    // Figure out maximum partition devices supported
549    unsigned int majorId = major(mDevice);
550    switch (majorId) {
551    case kMajorBlockLoop: {
552        std::string tmp;
553        if (!ReadFileToString(kSysfsLoopMaxMinors, &tmp)) {
554            LOG(ERROR) << "Failed to read max minors";
555            return -errno;
556        }
557        return atoi(tmp.c_str());
558    }
559    case kMajorBlockScsiA: case kMajorBlockScsiB: case kMajorBlockScsiC: case kMajorBlockScsiD:
560    case kMajorBlockScsiE: case kMajorBlockScsiF: case kMajorBlockScsiG: case kMajorBlockScsiH:
561    case kMajorBlockScsiI: case kMajorBlockScsiJ: case kMajorBlockScsiK: case kMajorBlockScsiL:
562    case kMajorBlockScsiM: case kMajorBlockScsiN: case kMajorBlockScsiO: case kMajorBlockScsiP: {
563        // Per Documentation/devices.txt this is static
564        return 15;
565    }
566    case kMajorBlockMmc: {
567        // Per Documentation/devices.txt this is dynamic
568        std::string tmp;
569        if (!ReadFileToString(kSysfsMmcMaxMinors, &tmp)) {
570            LOG(ERROR) << "Failed to read max minors";
571            return -errno;
572        }
573        return atoi(tmp.c_str());
574    }
575    default: {
576        if (isVirtioBlkDevice(majorId)) {
577            // drivers/block/virtio_blk.c has "#define PART_BITS 4", so max is
578            // 2^4 - 1 = 15
579            return 15;
580        }
581    }
582    }
583
584    LOG(ERROR) << "Unsupported block major type " << majorId;
585    return -ENOTSUP;
586}
587
588}  // namespace vold
589}  // namespace android
590