Disk.cpp revision f84fe907141bcdb76425d5ba42913576f018a11c 
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
25#include <android-base/file.h>
26#include <android-base/stringprintf.h>
27#include <android-base/logging.h>
28#include <diskconfig/diskconfig.h>
29
30#include <vector>
31#include <fcntl.h>
32#include <inttypes.h>
33#include <stdio.h>
34#include <stdlib.h>
35#include <sys/types.h>
36#include <sys/stat.h>
37#include <sys/mount.h>
38
39using android::base::ReadFileToString;
40using android::base::WriteStringToFile;
41using android::base::StringPrintf;
42
43namespace android {
44namespace vold {
45
46static const char* kSgdiskPath = "/system/bin/sgdisk";
47static const char* kSgdiskToken = " \t\n";
48
49static const char* kSysfsMmcMaxMinors = "/sys/module/mmcblk/parameters/perdev_minors";
50
51static const unsigned int kMajorBlockScsiA = 8;
52static const unsigned int kMajorBlockScsiB = 65;
53static const unsigned int kMajorBlockScsiC = 66;
54static const unsigned int kMajorBlockScsiD = 67;
55static const unsigned int kMajorBlockScsiE = 68;
56static const unsigned int kMajorBlockScsiF = 69;
57static const unsigned int kMajorBlockScsiG = 70;
58static const unsigned int kMajorBlockScsiH = 71;
59static const unsigned int kMajorBlockScsiI = 128;
60static const unsigned int kMajorBlockScsiJ = 129;
61static const unsigned int kMajorBlockScsiK = 130;
62static const unsigned int kMajorBlockScsiL = 131;
63static const unsigned int kMajorBlockScsiM = 132;
64static const unsigned int kMajorBlockScsiN = 133;
65static const unsigned int kMajorBlockScsiO = 134;
66static const unsigned int kMajorBlockScsiP = 135;
67static const unsigned int kMajorBlockMmc = 179;
68static const unsigned int kMajorBlockExperimentalMin = 240;
69static const unsigned int kMajorBlockExperimentalMax = 254;
70
71static const char* kGptBasicData = "EBD0A0A2-B9E5-4433-87C0-68B6B72699C7";
72static const char* kGptAndroidMeta = "19A710A2-B3CA-11E4-B026-10604B889DCF";
73static const char* kGptAndroidExpand = "193D1EA4-B3CA-11E4-B075-10604B889DCF";
74
75enum class Table {
76    kUnknown,
77    kMbr,
78    kGpt,
79};
80
81static bool isVirtioBlkDevice(unsigned int major) {
82    /*
83     * The new emulator's "ranchu" virtual board no longer includes a goldfish
84     * MMC-based SD card device; instead, it emulates SD cards with virtio-blk,
85     * which has been supported by upstream kernel and QEMU for quite a while.
86     * Unfortunately, the virtio-blk block device driver does not use a fixed
87     * major number, but relies on the kernel to assign one from a specific
88     * range of block majors, which are allocated for "LOCAL/EXPERIMENAL USE"
89     * per Documentation/devices.txt. This is true even for the latest Linux
90     * kernel (4.4; see init() in drivers/block/virtio_blk.c).
91     *
92     * This makes it difficult for vold to detect a virtio-blk based SD card.
93     * The current solution checks two conditions (both must be met):
94     *
95     *  a) If the running environment is the emulator;
96     *  b) If the major number is an experimental block device major number (for
97     *     x86/x86_64 3.10 ranchu kernels, virtio-blk always gets major number
98     *     253, but it is safer to match the range than just one value).
99     *
100     * Other conditions could be used, too, e.g. the hardware name should be
101     * "ranchu", the device's sysfs path should end with "/block/vd[d-z]", etc.
102     * But just having a) and b) is enough for now.
103     */
104    return IsRunningInEmulator() && major >= kMajorBlockExperimentalMin
105            && major <= kMajorBlockExperimentalMax;
106}
107
108Disk::Disk(const std::string& eventPath, dev_t device,
109        const std::string& nickname, int flags) :
110        mDevice(device), mSize(-1), mNickname(nickname), mFlags(flags), mCreated(
111                false), mJustPartitioned(false) {
112    mId = StringPrintf("disk:%u,%u", major(device), minor(device));
113    mEventPath = eventPath;
114    mSysPath = StringPrintf("/sys/%s", eventPath.c_str());
115    mDevPath = StringPrintf("/dev/block/vold/%s", mId.c_str());
116    CreateDeviceNode(mDevPath, mDevice);
117}
118
119Disk::~Disk() {
120    CHECK(!mCreated);
121    DestroyDeviceNode(mDevPath);
122}
123
124std::shared_ptr<VolumeBase> Disk::findVolume(const std::string& id) {
125    for (auto vol : mVolumes) {
126        if (vol->getId() == id) {
127            return vol;
128        }
129        auto stackedVol = vol->findVolume(id);
130        if (stackedVol != nullptr) {
131            return stackedVol;
132        }
133    }
134    return nullptr;
135}
136
137void Disk::listVolumes(VolumeBase::Type type, std::list<std::string>& list) {
138    for (auto vol : mVolumes) {
139        if (vol->getType() == type) {
140            list.push_back(vol->getId());
141        }
142        // TODO: consider looking at stacked volumes
143    }
144}
145
146status_t Disk::create() {
147    CHECK(!mCreated);
148    mCreated = true;
149    notifyEvent(ResponseCode::DiskCreated, StringPrintf("%d", mFlags));
150    readMetadata();
151    readPartitions();
152    return OK;
153}
154
155status_t Disk::destroy() {
156    CHECK(mCreated);
157    destroyAllVolumes();
158    mCreated = false;
159    notifyEvent(ResponseCode::DiskDestroyed);
160    return OK;
161}
162
163void Disk::createPublicVolume(dev_t device) {
164    auto vol = std::shared_ptr<VolumeBase>(new PublicVolume(device));
165    if (mJustPartitioned) {
166        LOG(DEBUG) << "Device just partitioned; silently formatting";
167        vol->setSilent(true);
168        vol->create();
169        vol->format("auto");
170        vol->destroy();
171        vol->setSilent(false);
172    }
173
174    mVolumes.push_back(vol);
175    vol->setDiskId(getId());
176    vol->create();
177}
178
179void Disk::createPrivateVolume(dev_t device, const std::string& partGuid) {
180    std::string normalizedGuid;
181    if (NormalizeHex(partGuid, normalizedGuid)) {
182        LOG(WARNING) << "Invalid GUID " << partGuid;
183        return;
184    }
185
186    std::string keyRaw;
187    if (!ReadFileToString(BuildKeyPath(normalizedGuid), &keyRaw)) {
188        PLOG(ERROR) << "Failed to load key for GUID " << normalizedGuid;
189        return;
190    }
191
192    LOG(DEBUG) << "Found key for GUID " << normalizedGuid;
193
194    auto vol = std::shared_ptr<VolumeBase>(new PrivateVolume(device, keyRaw));
195    if (mJustPartitioned) {
196        LOG(DEBUG) << "Device just partitioned; silently formatting";
197        vol->setSilent(true);
198        vol->create();
199        vol->format("auto");
200        vol->destroy();
201        vol->setSilent(false);
202    }
203
204    mVolumes.push_back(vol);
205    vol->setDiskId(getId());
206    vol->setPartGuid(partGuid);
207    vol->create();
208}
209
210void Disk::destroyAllVolumes() {
211    for (auto vol : mVolumes) {
212        vol->destroy();
213    }
214    mVolumes.clear();
215}
216
217status_t Disk::readMetadata() {
218    mSize = -1;
219    mLabel.clear();
220
221    int fd = open(mDevPath.c_str(), O_RDONLY | O_CLOEXEC);
222    if (fd != -1) {
223        if (ioctl(fd, BLKGETSIZE64, &mSize)) {
224            mSize = -1;
225        }
226        close(fd);
227    }
228
229    unsigned int majorId = major(mDevice);
230    switch (majorId) {
231    case kMajorBlockScsiA: case kMajorBlockScsiB: case kMajorBlockScsiC: case kMajorBlockScsiD:
232    case kMajorBlockScsiE: case kMajorBlockScsiF: case kMajorBlockScsiG: case kMajorBlockScsiH:
233    case kMajorBlockScsiI: case kMajorBlockScsiJ: case kMajorBlockScsiK: case kMajorBlockScsiL:
234    case kMajorBlockScsiM: case kMajorBlockScsiN: case kMajorBlockScsiO: case kMajorBlockScsiP: {
235        std::string path(mSysPath + "/device/vendor");
236        std::string tmp;
237        if (!ReadFileToString(path, &tmp)) {
238            PLOG(WARNING) << "Failed to read vendor from " << path;
239            return -errno;
240        }
241        mLabel = tmp;
242        break;
243    }
244    case kMajorBlockMmc: {
245        std::string path(mSysPath + "/device/manfid");
246        std::string tmp;
247        if (!ReadFileToString(path, &tmp)) {
248            PLOG(WARNING) << "Failed to read manufacturer from " << path;
249            return -errno;
250        }
251        uint64_t manfid = strtoll(tmp.c_str(), nullptr, 16);
252        // Our goal here is to give the user a meaningful label, ideally
253        // matching whatever is silk-screened on the card.  To reduce
254        // user confusion, this list doesn't contain white-label manfid.
255        switch (manfid) {
256        case 0x000003: mLabel = "SanDisk"; break;
257        case 0x00001b: mLabel = "Samsung"; break;
258        case 0x000028: mLabel = "Lexar"; break;
259        case 0x000074: mLabel = "Transcend"; break;
260        }
261        break;
262    }
263    default: {
264        if (isVirtioBlkDevice(majorId)) {
265            LOG(DEBUG) << "Recognized experimental block major ID " << majorId
266                    << " as virtio-blk (emulator's virtual SD card device)";
267            mLabel = "Virtual";
268            break;
269        }
270        LOG(WARNING) << "Unsupported block major type " << majorId;
271        return -ENOTSUP;
272    }
273    }
274
275    notifyEvent(ResponseCode::DiskSizeChanged, StringPrintf("%" PRIu64, mSize));
276    notifyEvent(ResponseCode::DiskLabelChanged, mLabel);
277    notifyEvent(ResponseCode::DiskSysPathChanged, mSysPath);
278    return OK;
279}
280
281status_t Disk::readPartitions() {
282    int8_t maxMinors = getMaxMinors();
283    if (maxMinors < 0) {
284        return -ENOTSUP;
285    }
286
287    destroyAllVolumes();
288
289    // Parse partition table
290
291    std::vector<std::string> cmd;
292    cmd.push_back(kSgdiskPath);
293    cmd.push_back("--android-dump");
294    cmd.push_back(mDevPath);
295
296    std::vector<std::string> output;
297    status_t res = ForkExecvp(cmd, output);
298    if (res != OK) {
299        LOG(WARNING) << "sgdisk failed to scan " << mDevPath;
300        notifyEvent(ResponseCode::DiskScanned);
301        mJustPartitioned = false;
302        return res;
303    }
304
305    Table table = Table::kUnknown;
306    bool foundParts = false;
307    for (auto line : output) {
308        char* cline = (char*) line.c_str();
309        char* token = strtok(cline, kSgdiskToken);
310        if (token == nullptr) continue;
311
312        if (!strcmp(token, "DISK")) {
313            const char* type = strtok(nullptr, kSgdiskToken);
314            if (!strcmp(type, "mbr")) {
315                table = Table::kMbr;
316            } else if (!strcmp(type, "gpt")) {
317                table = Table::kGpt;
318            }
319        } else if (!strcmp(token, "PART")) {
320            foundParts = true;
321            int i = strtol(strtok(nullptr, kSgdiskToken), nullptr, 10);
322            if (i <= 0 || i > maxMinors) {
323                LOG(WARNING) << mId << " is ignoring partition " << i
324                        << " beyond max supported devices";
325                continue;
326            }
327            dev_t partDevice = makedev(major(mDevice), minor(mDevice) + i);
328
329            if (table == Table::kMbr) {
330                const char* type = strtok(nullptr, kSgdiskToken);
331
332                switch (strtol(type, nullptr, 16)) {
333                case 0x06: // FAT16
334                case 0x0b: // W95 FAT32 (LBA)
335                case 0x0c: // W95 FAT32 (LBA)
336                case 0x0e: // W95 FAT16 (LBA)
337                    createPublicVolume(partDevice);
338                    break;
339                }
340            } else if (table == Table::kGpt) {
341                const char* typeGuid = strtok(nullptr, kSgdiskToken);
342                const char* partGuid = strtok(nullptr, kSgdiskToken);
343
344                if (!strcasecmp(typeGuid, kGptBasicData)) {
345                    createPublicVolume(partDevice);
346                } else if (!strcasecmp(typeGuid, kGptAndroidExpand)) {
347                    createPrivateVolume(partDevice, partGuid);
348                }
349            }
350        }
351    }
352
353    // Ugly last ditch effort, treat entire disk as partition
354    if (table == Table::kUnknown || !foundParts) {
355        LOG(WARNING) << mId << " has unknown partition table; trying entire device";
356
357        std::string fsType;
358        std::string unused;
359        if (ReadMetadataUntrusted(mDevPath, fsType, unused, unused) == OK) {
360            createPublicVolume(mDevice);
361        } else {
362            LOG(WARNING) << mId << " failed to identify, giving up";
363        }
364    }
365
366    notifyEvent(ResponseCode::DiskScanned);
367    mJustPartitioned = false;
368    return OK;
369}
370
371status_t Disk::unmountAll() {
372    for (auto vol : mVolumes) {
373        vol->unmount();
374    }
375    return OK;
376}
377
378status_t Disk::partitionPublic() {
379    int res;
380
381    // TODO: improve this code
382    destroyAllVolumes();
383    mJustPartitioned = true;
384
385    // First nuke any existing partition table
386    std::vector<std::string> cmd;
387    cmd.push_back(kSgdiskPath);
388    cmd.push_back("--zap-all");
389    cmd.push_back(mDevPath);
390
391    // Zap sometimes returns an error when it actually succeeded, so
392    // just log as warning and keep rolling forward.
393    if ((res = ForkExecvp(cmd)) != 0) {
394        LOG(WARNING) << "Failed to zap; status " << res;
395    }
396
397    struct disk_info dinfo;
398    memset(&dinfo, 0, sizeof(dinfo));
399
400    if (!(dinfo.part_lst = (struct part_info *) malloc(
401            MAX_NUM_PARTS * sizeof(struct part_info)))) {
402        return -1;
403    }
404
405    memset(dinfo.part_lst, 0, MAX_NUM_PARTS * sizeof(struct part_info));
406    dinfo.device = strdup(mDevPath.c_str());
407    dinfo.scheme = PART_SCHEME_MBR;
408    dinfo.sect_size = 512;
409    dinfo.skip_lba = 2048;
410    dinfo.num_lba = 0;
411    dinfo.num_parts = 1;
412
413    struct part_info *pinfo = &dinfo.part_lst[0];
414
415    pinfo->name = strdup("android_sdcard");
416    pinfo->flags |= PART_ACTIVE_FLAG;
417    pinfo->type = PC_PART_TYPE_FAT32;
418    pinfo->len_kb = -1;
419
420    int rc = apply_disk_config(&dinfo, 0);
421    if (rc) {
422        LOG(ERROR) << "Failed to apply disk configuration: " << rc;
423        goto out;
424    }
425
426out:
427    free(pinfo->name);
428    free(dinfo.device);
429    free(dinfo.part_lst);
430
431    return rc;
432}
433
434status_t Disk::partitionPrivate() {
435    return partitionMixed(0);
436}
437
438status_t Disk::partitionMixed(int8_t ratio) {
439    int res;
440
441    destroyAllVolumes();
442    mJustPartitioned = true;
443
444    // First nuke any existing partition table
445    std::vector<std::string> cmd;
446    cmd.push_back(kSgdiskPath);
447    cmd.push_back("--zap-all");
448    cmd.push_back(mDevPath);
449
450    // Zap sometimes returns an error when it actually succeeded, so
451    // just log as warning and keep rolling forward.
452    if ((res = ForkExecvp(cmd)) != 0) {
453        LOG(WARNING) << "Failed to zap; status " << res;
454    }
455
456    // We've had some success above, so generate both the private partition
457    // GUID and encryption key and persist them.
458    std::string partGuidRaw;
459    std::string keyRaw;
460    if (ReadRandomBytes(16, partGuidRaw) || ReadRandomBytes(16, keyRaw)) {
461        LOG(ERROR) << "Failed to generate GUID or key";
462        return -EIO;
463    }
464
465    std::string partGuid;
466    StrToHex(partGuidRaw, partGuid);
467
468    if (!WriteStringToFile(keyRaw, BuildKeyPath(partGuid))) {
469        LOG(ERROR) << "Failed to persist key";
470        return -EIO;
471    } else {
472        LOG(DEBUG) << "Persisted key for GUID " << partGuid;
473    }
474
475    // Now let's build the new GPT table. We heavily rely on sgdisk to
476    // force optimal alignment on the created partitions.
477    cmd.clear();
478    cmd.push_back(kSgdiskPath);
479
480    // If requested, create a public partition first. Mixed-mode partitioning
481    // like this is an experimental feature.
482    if (ratio > 0) {
483        if (ratio < 10 || ratio > 90) {
484            LOG(ERROR) << "Mixed partition ratio must be between 10-90%";
485            return -EINVAL;
486        }
487
488        uint64_t splitMb = ((mSize / 100) * ratio) / 1024 / 1024;
489        cmd.push_back(StringPrintf("--new=0:0:+%" PRId64 "M", splitMb));
490        cmd.push_back(StringPrintf("--typecode=0:%s", kGptBasicData));
491        cmd.push_back("--change-name=0:shared");
492    }
493
494    // Define a metadata partition which is designed for future use; there
495    // should only be one of these per physical device, even if there are
496    // multiple private volumes.
497    cmd.push_back("--new=0:0:+16M");
498    cmd.push_back(StringPrintf("--typecode=0:%s", kGptAndroidMeta));
499    cmd.push_back("--change-name=0:android_meta");
500
501    // Define a single private partition filling the rest of disk.
502    cmd.push_back("--new=0:0:-0");
503    cmd.push_back(StringPrintf("--typecode=0:%s", kGptAndroidExpand));
504    cmd.push_back(StringPrintf("--partition-guid=0:%s", partGuid.c_str()));
505    cmd.push_back("--change-name=0:android_expand");
506
507    cmd.push_back(mDevPath);
508
509    if ((res = ForkExecvp(cmd)) != 0) {
510        LOG(ERROR) << "Failed to partition; status " << res;
511        return res;
512    }
513
514    return OK;
515}
516
517void Disk::notifyEvent(int event) {
518    VolumeManager::Instance()->getBroadcaster()->sendBroadcast(event,
519            getId().c_str(), false);
520}
521
522void Disk::notifyEvent(int event, const std::string& value) {
523    VolumeManager::Instance()->getBroadcaster()->sendBroadcast(event,
524            StringPrintf("%s %s", getId().c_str(), value.c_str()).c_str(), false);
525}
526
527int Disk::getMaxMinors() {
528    // Figure out maximum partition devices supported
529    unsigned int majorId = major(mDevice);
530    switch (majorId) {
531    case kMajorBlockScsiA: case kMajorBlockScsiB: case kMajorBlockScsiC: case kMajorBlockScsiD:
532    case kMajorBlockScsiE: case kMajorBlockScsiF: case kMajorBlockScsiG: case kMajorBlockScsiH:
533    case kMajorBlockScsiI: case kMajorBlockScsiJ: case kMajorBlockScsiK: case kMajorBlockScsiL:
534    case kMajorBlockScsiM: case kMajorBlockScsiN: case kMajorBlockScsiO: case kMajorBlockScsiP: {
535        // Per Documentation/devices.txt this is static
536        return 15;
537    }
538    case kMajorBlockMmc: {
539        // Per Documentation/devices.txt this is dynamic
540        std::string tmp;
541        if (!ReadFileToString(kSysfsMmcMaxMinors, &tmp)) {
542            LOG(ERROR) << "Failed to read max minors";
543            return -errno;
544        }
545        return atoi(tmp.c_str());
546    }
547    default: {
548        if (isVirtioBlkDevice(majorId)) {
549            // drivers/block/virtio_blk.c has "#define PART_BITS 4", so max is
550            // 2^4 - 1 = 15
551            return 15;
552        }
553    }
554    }
555
556    LOG(ERROR) << "Unsupported block major type " << majorId;
557    return -ENOTSUP;
558}
559
560}  // namespace vold
561}  // namespace android
562