recovery: Implement a volume manager

This is a copy of the pre-binderized vold which has been converted to
use direct calls instead of sockets and stripped down to only what is
needed to support recovery.

Includes:
  * recovery: volmgr: remove unused IsSupported

    Change-Id: If8206658fdfb6108221806c09c99bf0a30f4a586
    Signed-off-by: Jesse Chan <jc@lineageos.org>

  * recovery: volmgr: remove filesystem checks

    Those checks are not strictly necessary and we are
    not building fsck tools for recovery for now.

    Remove those checks so volmgr can be useful.

    Change-Id: I87756c61b933b6cdccd281c6276b686fbd36019f
    Signed-off-by: Jesse Chan <jc@lineageos.org>

  * recovery: fixup `EmulatedVolume creating`

    Avoid dangling pointer. Instead of pointing to FstabEntry create copy.

    Change-Id: I57f76006db09a6add2c173f43175f0f6b848d87b

  * recovery: fix volmgr cleaning up

    Don't reset pointer to netlink manager
    Delete disks in stop() rather then in ~VolumeManager
    Call destroy() before deleting disks cause delete expects the
      disk to be destroyed
    Clear the lists or we would read garbage data on the next scan

    Change-Id: Idadfa1f33b7cb5f2f3c780848a99344a6608420e

  * recovery: handle interrupts in apply update menu

    Change-Id: I1f78f9196634353b77986545332d7d52a5f0c161

Change-Id: Ic82d929e052b5ba70ecf7b475e0a223d77d9687e
diff --git a/volume_manager/Disk.cpp b/volume_manager/Disk.cpp
new file mode 100644
index 0000000..832d61b
--- /dev/null
+++ b/volume_manager/Disk.cpp
@@ -0,0 +1,424 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * Copyright (C) 2019 The LineageOS Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Disk.h"
+#include "PublicVolume.h"
+#include <volume_manager/ResponseCode.h>
+#include <volume_manager/VolumeManager.h>
+#include "Utils.h"
+#include "VolumeBase.h"
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+#include <android-base/stringprintf.h>
+#include <diskconfig/diskconfig.h>
+
+#include <sgdisk.h>
+
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <sys/types.h>
+#include <vector>
+
+using android::base::ReadFileToString;
+using android::base::WriteStringToFile;
+using android::base::StringPrintf;
+
+namespace android {
+namespace volmgr {
+
+static const char* kSysfsLoopMaxMinors = "/sys/module/loop/parameters/max_part";
+static const char* kSysfsMmcMaxMinorsDeprecated = "/sys/module/mmcblk/parameters/perdev_minors";
+static const char* kSysfsMmcMaxMinors = "/sys/module/mmc_block/parameters/perdev_minors";
+
+static const unsigned int kMajorBlockLoop = 7;
+static const unsigned int kMajorBlockScsiA = 8;
+static const unsigned int kMajorBlockScsiB = 65;
+static const unsigned int kMajorBlockScsiC = 66;
+static const unsigned int kMajorBlockScsiD = 67;
+static const unsigned int kMajorBlockScsiE = 68;
+static const unsigned int kMajorBlockScsiF = 69;
+static const unsigned int kMajorBlockScsiG = 70;
+static const unsigned int kMajorBlockScsiH = 71;
+static const unsigned int kMajorBlockScsiI = 128;
+static const unsigned int kMajorBlockScsiJ = 129;
+static const unsigned int kMajorBlockScsiK = 130;
+static const unsigned int kMajorBlockScsiL = 131;
+static const unsigned int kMajorBlockScsiM = 132;
+static const unsigned int kMajorBlockScsiN = 133;
+static const unsigned int kMajorBlockScsiO = 134;
+static const unsigned int kMajorBlockScsiP = 135;
+static const unsigned int kMajorBlockMmc = 179;
+static const unsigned int kMajorBlockExperimentalMin = 240;
+static const unsigned int kMajorBlockExperimentalMax = 254;
+
+static const char* kGptBasicData = "EBD0A0A2-B9E5-4433-87C0-68B6B72699C7";
+static const char* kGptLinuxFilesystem = "0FC63DAF-8483-4772-8E79-3D69D8477DE4";
+
+enum class Table {
+    kUnknown,
+    kMbr,
+    kGpt,
+};
+
+static bool isVirtioBlkDevice(unsigned int major) {
+    /*
+     * The new emulator's "ranchu" virtual board no longer includes a goldfish
+     * MMC-based SD card device; instead, it emulates SD cards with virtio-blk,
+     * which has been supported by upstream kernel and QEMU for quite a while.
+     * Unfortunately, the virtio-blk block device driver does not use a fixed
+     * major number, but relies on the kernel to assign one from a specific
+     * range of block majors, which are allocated for "LOCAL/EXPERIMENAL USE"
+     * per Documentation/devices.txt. This is true even for the latest Linux
+     * kernel (4.4; see init() in drivers/block/virtio_blk.c).
+     *
+     * This makes it difficult for vold to detect a virtio-blk based SD card.
+     * The current solution checks two conditions (both must be met):
+     *
+     *  a) If the running environment is the emulator;
+     *  b) If the major number is an experimental block device major number (for
+     *     x86/x86_64 3.10 ranchu kernels, virtio-blk always gets major number
+     *     253, but it is safer to match the range than just one value).
+     *
+     * Other conditions could be used, too, e.g. the hardware name should be
+     * "ranchu", the device's sysfs path should end with "/block/vd[d-z]", etc.
+     * But just having a) and b) is enough for now.
+     */
+    return IsRunningInEmulator() && major >= kMajorBlockExperimentalMin &&
+           major <= kMajorBlockExperimentalMax;
+}
+
+Disk::Disk(const std::string& eventPath, dev_t device, const std::string& nickname, int flags)
+    : mDevice(device),
+      mSize(-1),
+      mNickname(nickname),
+      mFlags(flags),
+      mCreated(false),
+      mSkipChange(false) {
+    mId = StringPrintf("disk:%u_%u", major(device), minor(device));
+    mEventPath = eventPath;
+    mSysPath = StringPrintf("/sys/%s", eventPath.c_str());
+    mDevPath = StringPrintf("/dev/block/volmgr/%s", mId.c_str());
+    CreateDeviceNode(mDevPath, mDevice);
+}
+
+Disk::~Disk() {
+    CHECK(!mCreated);
+    DestroyDeviceNode(mDevPath);
+}
+
+void Disk::getVolumeInfo(std::vector<VolumeInfo>& info) {
+    for (auto vol : mVolumes) {
+        info.push_back(VolumeInfo(vol.get()));
+    }
+}
+
+std::shared_ptr<VolumeBase> Disk::findVolume(const std::string& id) {
+    for (auto vol : mVolumes) {
+        if (vol->getId() == id) {
+            return vol;
+        }
+    }
+    return nullptr;
+}
+
+void Disk::listVolumes(VolumeBase::Type type, std::list<std::string>& list) {
+    for (const auto& vol : mVolumes) {
+        if (vol->getType() == type) {
+            list.push_back(vol->getId());
+        }
+        // TODO: consider looking at stacked volumes
+    }
+}
+
+status_t Disk::create() {
+    CHECK(!mCreated);
+    mCreated = true;
+    VolumeManager::Instance()->notifyEvent(ResponseCode::DiskCreated, StringPrintf("%d", mFlags));
+    readMetadata();
+    readPartitions();
+    return OK;
+}
+
+status_t Disk::destroy() {
+    CHECK(mCreated);
+    destroyAllVolumes();
+    mCreated = false;
+    VolumeManager::Instance()->notifyEvent(ResponseCode::DiskDestroyed);
+    return OK;
+}
+
+void Disk::createPublicVolume(dev_t device, const std::string& fstype /* = "" */,
+                              const std::string& mntopts /* = "" */) {
+    auto vol = std::shared_ptr<VolumeBase>(new PublicVolume(device, mNickname, fstype, mntopts));
+
+    mVolumes.push_back(vol);
+    vol->setDiskId(getId());
+    vol->create();
+}
+
+void Disk::destroyAllVolumes() {
+    for (const auto& vol : mVolumes) {
+        vol->destroy();
+    }
+    mVolumes.clear();
+}
+
+status_t Disk::readMetadata() {
+    if (mSkipChange) {
+        return OK;
+    }
+
+    mSize = -1;
+    mLabel.clear();
+
+    int fd = open(mDevPath.c_str(), O_RDONLY | O_CLOEXEC);
+    if (fd != -1) {
+        if (ioctl(fd, BLKGETSIZE64, &mSize)) {
+            mSize = -1;
+        }
+        close(fd);
+    }
+
+    unsigned int majorId = major(mDevice);
+    switch (majorId) {
+        case kMajorBlockLoop: {
+            mLabel = "Virtual";
+            break;
+        }
+        case kMajorBlockScsiA:
+        case kMajorBlockScsiB:
+        case kMajorBlockScsiC:
+        case kMajorBlockScsiD:
+        case kMajorBlockScsiE:
+        case kMajorBlockScsiF:
+        case kMajorBlockScsiG:
+        case kMajorBlockScsiH:
+        case kMajorBlockScsiI:
+        case kMajorBlockScsiJ:
+        case kMajorBlockScsiK:
+        case kMajorBlockScsiL:
+        case kMajorBlockScsiM:
+        case kMajorBlockScsiN:
+        case kMajorBlockScsiO:
+        case kMajorBlockScsiP: {
+            std::string path(mSysPath + "/device/vendor");
+            std::string tmp;
+            if (!ReadFileToString(path, &tmp)) {
+                PLOG(WARNING) << "Failed to read vendor from " << path;
+                return -errno;
+            }
+            mLabel = tmp;
+            break;
+        }
+        case kMajorBlockMmc: {
+            std::string path(mSysPath + "/device/manfid");
+            std::string tmp;
+            if (!ReadFileToString(path, &tmp)) {
+                PLOG(WARNING) << "Failed to read manufacturer from " << path;
+                return -errno;
+            }
+            uint64_t manfid = strtoll(tmp.c_str(), nullptr, 16);
+            // Our goal here is to give the user a meaningful label, ideally
+            // matching whatever is silk-screened on the card.  To reduce
+            // user confusion, this list doesn't contain white-label manfid.
+            switch (manfid) {
+                case 0x000003:
+                    mLabel = "SanDisk";
+                    break;
+                case 0x00001b:
+                    mLabel = "Samsung";
+                    break;
+                case 0x000028:
+                    mLabel = "Lexar";
+                    break;
+                case 0x000074:
+                    mLabel = "Transcend";
+                    break;
+            }
+            break;
+        }
+        default: {
+            if (isVirtioBlkDevice(majorId)) {
+                LOG(DEBUG) << "Recognized experimental block major ID " << majorId
+                           << " as virtio-blk (emulator's virtual SD card device)";
+                mLabel = "Virtual";
+                break;
+            }
+            LOG(WARNING) << "Unsupported block major type " << majorId;
+            return -ENOTSUP;
+        }
+    }
+
+    VolumeManager::Instance()->notifyEvent(ResponseCode::DiskSizeChanged,
+                                           StringPrintf("%" PRIu64, mSize));
+    VolumeManager::Instance()->notifyEvent(ResponseCode::DiskLabelChanged, mLabel);
+    VolumeManager::Instance()->notifyEvent(ResponseCode::DiskSysPathChanged, mSysPath);
+    return OK;
+}
+
+status_t Disk::readPartitions() {
+    int8_t maxMinors = getMaxMinors();
+    if (maxMinors < 0) {
+        return -ENOTSUP;
+    }
+
+    if (mSkipChange) {
+        mSkipChange = false;
+        LOG(INFO) << "Skip first change";
+        return OK;
+    }
+
+    destroyAllVolumes();
+
+    // Parse partition table
+    sgdisk_partition_table ptbl;
+    std::vector<sgdisk_partition> partitions;
+    int res = sgdisk_read(mDevPath.c_str(), ptbl, partitions);
+    if (res != 0) {
+        LOG(WARNING) << "sgdisk failed to scan " << mDevPath;
+        VolumeManager::Instance()->notifyEvent(ResponseCode::DiskScanned);
+        return res;
+    }
+
+    Table table = Table::kUnknown;
+    bool foundParts = false;
+
+    switch (ptbl.type) {
+        case MBR:
+            table = Table::kMbr;
+            break;
+        case GPT:
+            table = Table::kGpt;
+            break;
+        default:
+            table = Table::kUnknown;
+    }
+
+    foundParts = partitions.size() > 0;
+    for (const auto& part : partitions) {
+        if (part.num <= 0 || part.num > maxMinors) {
+            LOG(WARNING) << mId << " is ignoring partition " << part.num
+                         << " beyond max supported devices";
+            continue;
+        }
+        dev_t partDevice = makedev(major(mDevice), minor(mDevice) + part.num);
+        if (table == Table::kMbr) {
+            switch (strtol(part.type.c_str(), nullptr, 16)) {
+                case 0x06:  // FAT16
+                case 0x07:  // NTFS/exFAT
+                case 0x0b:  // W95 FAT32 (LBA)
+                case 0x0c:  // W95 FAT32 (LBA)
+                case 0x0e:  // W95 FAT16 (LBA)
+                case 0x83:  // Linux EXT4/F2FS/...
+                    createPublicVolume(partDevice);
+                    break;
+            }
+        } else if (table == Table::kGpt) {
+            if (!strcasecmp(part.guid.c_str(), kGptBasicData) ||
+                !strcasecmp(part.guid.c_str(), kGptLinuxFilesystem)) {
+                createPublicVolume(partDevice);
+            }
+        }
+    }
+
+    // Ugly last ditch effort, treat entire disk as partition
+    if (table == Table::kUnknown || !foundParts) {
+        LOG(WARNING) << mId << " has unknown partition table; trying entire device";
+
+        std::string fsType;
+        std::string unused;
+        if (ReadMetadataUntrusted(mDevPath, fsType, unused, unused) == OK) {
+            createPublicVolume(mDevice);
+        } else {
+            LOG(WARNING) << mId << " failed to identify, giving up";
+        }
+    }
+
+    VolumeManager::Instance()->notifyEvent(ResponseCode::DiskScanned);
+    return OK;
+}
+
+status_t Disk::unmountAll() {
+    for (const auto& vol : mVolumes) {
+        vol->unmount();
+    }
+    return OK;
+}
+
+int Disk::getMaxMinors() {
+    // Figure out maximum partition devices supported
+    unsigned int majorId = major(mDevice);
+    switch (majorId) {
+        case kMajorBlockLoop: {
+            std::string tmp;
+            if (!ReadFileToString(kSysfsLoopMaxMinors, &tmp)) {
+                LOG(ERROR) << "Failed to read max minors";
+                return -errno;
+            }
+            return atoi(tmp.c_str());
+        }
+        case kMajorBlockScsiA:
+        case kMajorBlockScsiB:
+        case kMajorBlockScsiC:
+        case kMajorBlockScsiD:
+        case kMajorBlockScsiE:
+        case kMajorBlockScsiF:
+        case kMajorBlockScsiG:
+        case kMajorBlockScsiH:
+        case kMajorBlockScsiI:
+        case kMajorBlockScsiJ:
+        case kMajorBlockScsiK:
+        case kMajorBlockScsiL:
+        case kMajorBlockScsiM:
+        case kMajorBlockScsiN:
+        case kMajorBlockScsiO:
+        case kMajorBlockScsiP: {
+            // Per Documentation/devices.txt this is static
+            return 15;
+        }
+        case kMajorBlockMmc: {
+            // Per Documentation/devices.txt this is dynamic
+            std::string tmp;
+            if (!ReadFileToString(kSysfsMmcMaxMinors, &tmp) &&
+                !ReadFileToString(kSysfsMmcMaxMinorsDeprecated, &tmp)) {
+                LOG(ERROR) << "Failed to read max minors";
+                return -errno;
+            }
+            return atoi(tmp.c_str());
+        }
+        default: {
+            if (isVirtioBlkDevice(majorId)) {
+                // drivers/block/virtio_blk.c has "#define PART_BITS 4", so max is
+                // 2^4 - 1 = 15
+                return 15;
+            }
+        }
+    }
+
+    LOG(ERROR) << "Unsupported block major type " << majorId;
+    return -ENOTSUP;
+}
+
+}  // namespace volmgr
+}  // namespace android