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 
39 using android::base::ReadFileToString;
40 using android::base::WriteStringToFile;
41 using android::base::StringPrintf;
42 
43 namespace android {
44 namespace vold {
45 
46 static const char* kSgdiskPath = "/system/bin/sgdisk";
47 static const char* kSgdiskToken = " \t\n";
48 
49 static const char* kSysfsMmcMaxMinors = "/sys/module/mmcblk/parameters/perdev_minors";
50 
51 static const unsigned int kMajorBlockScsiA = 8;
52 static const unsigned int kMajorBlockScsiB = 65;
53 static const unsigned int kMajorBlockScsiC = 66;
54 static const unsigned int kMajorBlockScsiD = 67;
55 static const unsigned int kMajorBlockScsiE = 68;
56 static const unsigned int kMajorBlockScsiF = 69;
57 static const unsigned int kMajorBlockScsiG = 70;
58 static const unsigned int kMajorBlockScsiH = 71;
59 static const unsigned int kMajorBlockScsiI = 128;
60 static const unsigned int kMajorBlockScsiJ = 129;
61 static const unsigned int kMajorBlockScsiK = 130;
62 static const unsigned int kMajorBlockScsiL = 131;
63 static const unsigned int kMajorBlockScsiM = 132;
64 static const unsigned int kMajorBlockScsiN = 133;
65 static const unsigned int kMajorBlockScsiO = 134;
66 static const unsigned int kMajorBlockScsiP = 135;
67 static const unsigned int kMajorBlockMmc = 179;
68 static const unsigned int kMajorBlockExperimentalMin = 240;
69 static const unsigned int kMajorBlockExperimentalMax = 254;
70 
71 static const char* kGptBasicData = "EBD0A0A2-B9E5-4433-87C0-68B6B72699C7";
72 static const char* kGptAndroidMeta = "19A710A2-B3CA-11E4-B026-10604B889DCF";
73 static const char* kGptAndroidExpand = "193D1EA4-B3CA-11E4-B075-10604B889DCF";
74 
75 enum class Table {
76     kUnknown,
77     kMbr,
78     kGpt,
79 };
80 
isVirtioBlkDevice(unsigned int major)81 static 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 
Disk(const std::string & eventPath,dev_t device,const std::string & nickname,int flags)108 Disk::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 
~Disk()119 Disk::~Disk() {
120     CHECK(!mCreated);
121     DestroyDeviceNode(mDevPath);
122 }
123 
findVolume(const std::string & id)124 std::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 
listVolumes(VolumeBase::Type type,std::list<std::string> & list)137 void 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 
create()146 status_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 
destroy()155 status_t Disk::destroy() {
156     CHECK(mCreated);
157     destroyAllVolumes();
158     mCreated = false;
159     notifyEvent(ResponseCode::DiskDestroyed);
160     return OK;
161 }
162 
createPublicVolume(dev_t device)163 void 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 
createPrivateVolume(dev_t device,const std::string & partGuid)179 void 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 
destroyAllVolumes()210 void Disk::destroyAllVolumes() {
211     for (auto vol : mVolumes) {
212         vol->destroy();
213     }
214     mVolumes.clear();
215 }
216 
readMetadata()217 status_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 
readPartitions()281 status_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 
unmountAll()371 status_t Disk::unmountAll() {
372     for (auto vol : mVolumes) {
373         vol->unmount();
374     }
375     return OK;
376 }
377 
partitionPublic()378 status_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 
426 out:
427     free(pinfo->name);
428     free(dinfo.device);
429     free(dinfo.part_lst);
430 
431     return rc;
432 }
433 
partitionPrivate()434 status_t Disk::partitionPrivate() {
435     return partitionMixed(0);
436 }
437 
partitionMixed(int8_t ratio)438 status_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 
notifyEvent(int event)517 void Disk::notifyEvent(int event) {
518     VolumeManager::Instance()->getBroadcaster()->sendBroadcast(event,
519             getId().c_str(), false);
520 }
521 
notifyEvent(int event,const std::string & value)522 void 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 
getMaxMinors()527 int 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