/*
 * Copyright (C) 2015 The Android Open Source 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 "PublicVolume.h"

#include "AppFuseUtil.h"
#include "Utils.h"
#include "VolumeManager.h"
#include "fs/Exfat.h"
#include "fs/Vfat.h"

// HUANGLONG add begin
#include "fs/Ext4.h"
#include "fs/Ntfs.h"
// HUANGLONG add end

#include <android-base/logging.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <cutils/fs.h>
#include <private/android_filesystem_config.h>
#include <utils/Timers.h>

#include <fcntl.h>
#include <stdlib.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include <sys/types.h>
#include <sys/wait.h>

using android::base::GetBoolProperty;
using android::base::StringPrintf;

namespace android {
namespace vold {

static const char* kSdcardFsPath = "/system/bin/sdcard";

static const char* kAsecPath = "/mnt/secure/asec";

// HUANGLONG add begin
#include "fs/Ext4.h"
#include "fs/Ntfs.h"
static const int MAX_PARTITION_NUM = 15;
static const int PERMMASK = 0006;

std::string diskNameToStableName(const std::string& diskname, int volNumber)
{
    const char* sdcardPrefix = "mmcblk";
    std::string mountpoint;
    if (volNumber < 0) {
        return diskname;
    }

    if (!strncmp(diskname.c_str(), sdcardPrefix, strlen(sdcardPrefix))) {
        // if volNumber == 0, means entire sdcard device,treate mountpoint as entire disk, such as mmcblk1
        mountpoint = (volNumber > 0) ? StringPrintf("%sp%d", diskname.c_str(), volNumber)
                                     : StringPrintf("%s", diskname.c_str());
    } else {
        // if volNumber == 0, means entire usb device,treate mountpoint as entire disk, such as sda
        mountpoint = (volNumber > 0) ? StringPrintf("%s%d", diskname.c_str(), volNumber)
                                     : StringPrintf("%s", diskname.c_str());
    }
    return mountpoint;
}
// HUANGLONG add end

PublicVolume::PublicVolume(dev_t device) : VolumeBase(Type::kPublic), mDevice(device) {
    setId(StringPrintf("public:%u,%u", major(device), minor(device)));
    mDevPath = StringPrintf("/dev/block/vold/%s", getId().c_str());
    mFuseMounted = false;
    mUseSdcardFs = IsSdcardfsUsed();
}

PublicVolume::~PublicVolume() {}

status_t PublicVolume::readMetadata() {
    status_t res = ReadMetadataUntrusted(mDevPath, &mFsType, &mFsUuid, &mFsLabel);

    auto listener = getListener();
    if (listener) listener->onVolumeMetadataChanged(getId(), mFsType, mFsUuid, mFsLabel);

    return res;
}

status_t PublicVolume::initAsecStage() {
    std::string legacyPath(mRawPath + "/android_secure");
    std::string securePath(mRawPath + "/.android_secure");

    // Recover legacy secure path
    if (!access(legacyPath.c_str(), R_OK | X_OK) && access(securePath.c_str(), R_OK | X_OK)) {
        if (rename(legacyPath.c_str(), securePath.c_str())) {
            PLOG(WARNING) << getId() << " failed to rename legacy ASEC dir";
        }
    }

    if (TEMP_FAILURE_RETRY(mkdir(securePath.c_str(), 0700))) {
        if (errno != EEXIST) {
            PLOG(WARNING) << getId() << " creating ASEC stage failed";
            return -errno;
        }
    }

    BindMount(securePath, kAsecPath);

    return OK;
}

status_t PublicVolume::doCreate() {
    return CreateDeviceNode(mDevPath, mDevice);
}

status_t PublicVolume::doDestroy() {
    return DestroyDeviceNode(mDevPath);
}

status_t PublicVolume::doMount() {
    bool isVisible = getMountFlags() & MountFlags::kVisible;
    readMetadata();

    // HUANGLONG modify begin
    // Due to usb compatibility issues,no need return I/O Error if filesystem check fail
    if (mFsType == "vfat" && vfat::IsSupported()) {
        if (vfat::Check(mDevPath)) {
            LOG(ERROR) << getId() << " failed filesystem check";
        }
    } else if (mFsType == "exfat") {
        LOG(ERROR) << "no support exfat filesystem";
        return -EIO;
    } else if (((mFsType == "ext2") || (mFsType == "ext3") || (mFsType == "ext4")) &&
               IsFilesystemSupported("ext4")) {
        // Ext2/3/4 use ext4 filesystem
        LOG(DEBUG) << "filesystem is ext2/3/4";
    } else if (mFsType == "ntfs" && IsFilesystemSupported("ntfs")) {
        LOG(DEBUG) << "filesystem is ntfs";
        if (ntfs::check(mDevPath)) {
            LOG(ERROR) << getId() << "failed ntfs filesystem check";
        }
    } else {
        LOG(ERROR) << getId() << " unsupported filesystem " << mFsType;
    }

    // Use UUID as stable name, if available
    std::string stableName = getId();
    if (!mFsUuid.empty()) {
        stableName = mFsUuid;
    }

    // No use disk fs uuid name as mount point name
    // single usb device has max 15 partitions
    stableName = diskNameToStableName(getDiskName(), minor(mDevice) % (MAX_PARTITION_NUM + 1));
    LOG(DEBUG) << "public volume mount : stableName = " << stableName;
    if (stableName.empty()) {
        return -EIO;
    }
    mStableName = stableName;
    // HUANGLONG modify end

    mRawPath = StringPrintf("/mnt/media_rw/%s", stableName.c_str());

    mSdcardFsDefault = StringPrintf("/mnt/runtime/default/%s", stableName.c_str());
    mSdcardFsRead = StringPrintf("/mnt/runtime/read/%s", stableName.c_str());
    mSdcardFsWrite = StringPrintf("/mnt/runtime/write/%s", stableName.c_str());
    mSdcardFsFull = StringPrintf("/mnt/runtime/full/%s", stableName.c_str());

    setInternalPath(mRawPath);
    if (isVisible) {
        setPath(StringPrintf("/storage/%s", stableName.c_str()));
    } else {
        setPath(mRawPath);
    }

    if (fs_prepare_dir(mRawPath.c_str(), 0700, AID_ROOT, AID_ROOT)) {
        PLOG(ERROR) << getId() << " failed to create mount points";
        return -errno;
    }

    // HUANGLONG modify begin
    if (mFsType == "vfat") {
        if (!vfat::Mount(mDevPath, mRawPath, false, false, false, AID_MEDIA_RW, AID_MEDIA_RW, PERMMASK,
                         true)) {
            PLOG(DEBUG) << mRawPath << " success to mount via vfat with mask 0006!";
        } else {
            PLOG(ERROR) << mRawPath << " mount vfat failed.";
            rmdir(mRawPath.c_str());
            return -EIO;
        }
    } else if (mFsType == "exfat") {
        if (!exfat::Mount(mDevPath, mRawPath, AID_MEDIA_RW, AID_MEDIA_RW, PERMMASK)) {
            PLOG(DEBUG) << mRawPath << " success to mount via exfat with mask 0006!";
        } else {
            PLOG(ERROR) << mRawPath << " mount exfat failed.";
            rmdir(mRawPath.c_str());
            return -EIO;
        }
    } else if (mFsType == "ext4" || mFsType == "ext3" || mFsType == "ext2") {
        if (!ext4::Mount(mDevPath, mRawPath, false, false, false, false, PERMMASK, AID_MEDIA_RW,
                         AID_SDCARD_RW)) {
            PLOG(DEBUG) << mRawPath << " success to mount via EXT4 !";
        } else {
            PLOG(ERROR) << mRawPath << " mount ext4 failed ";
            rmdir(mRawPath.c_str());
            return -EIO;
        }
    } else if (mFsType == "ntfs") {
        if (!ntfs::doMount(mDevPath, mRawPath, false, false, false, AID_MEDIA_RW, AID_SDCARD_RW,
                           PERMMASK, true)) {
            PLOG(DEBUG) << mRawPath << " success to mount via NTFS !";
        } else {
            PLOG(ERROR) << mRawPath << " mount ntfs failed.";
            rmdir(mRawPath.c_str());
            return -EIO;
        }
    } else {
        PLOG(ERROR) << " unknown filesystem , try vfat/ntfs/ext4 again." << std::endl;
        if (!vfat::Mount(mDevPath, mRawPath, false, false, false, AID_MEDIA_RW, AID_SDCARD_RW, PERMMASK,
                         true)) {
            LOG(DEBUG) << mRawPath << " success to mount via VFAT !" << std::endl;
        } else if (!ntfs::doMount(mDevPath, mRawPath, false, false, false, AID_MEDIA_RW,
                                  AID_SDCARD_RW, PERMMASK, true)) {
            LOG(DEBUG) << mRawPath << " success to mount via NTFS !" << std::endl;
        } else if (!ext4::Mount(mDevPath, mRawPath, false, false, false)) {
            LOG(DEBUG) << mRawPath << " success to mount via EXT4 !" << std::endl;
        } else {
            PLOG(ERROR) << mRawPath << " unknown filesystem, can not mount." << std::endl;
            rmdir(mRawPath.c_str());
            return -EIO;
        }
    }
    // HUANGLONG modify end

    if (getMountFlags() & MountFlags::kPrimary) {
        initAsecStage();
    }

    if (!isVisible) {
        // Not visible to apps, so no need to spin up sdcardfs or FUSE
        return OK;
    }

    if (mUseSdcardFs) {
        if (fs_prepare_dir(mSdcardFsDefault.c_str(), 0700, AID_ROOT, AID_ROOT) ||
            fs_prepare_dir(mSdcardFsRead.c_str(), 0700, AID_ROOT, AID_ROOT) ||
            fs_prepare_dir(mSdcardFsWrite.c_str(), 0700, AID_ROOT, AID_ROOT) ||
            fs_prepare_dir(mSdcardFsFull.c_str(), 0700, AID_ROOT, AID_ROOT)) {
            PLOG(ERROR) << getId() << " failed to create sdcardfs mount points";
            return -errno;
        }

        dev_t before = GetDevice(mSdcardFsFull);

        int sdcardFsPid;
        if (!(sdcardFsPid = fork())) {
            if (getMountFlags() & MountFlags::kPrimary) {
                // clang-format off
                if (execl(kSdcardFsPath, kSdcardFsPath,
                        "-u", "1023", // AID_MEDIA_RW
                        "-g", "1023", // AID_MEDIA_RW
                        "-U", std::to_string(getMountUserId()).c_str(),
                        "-w",
                        mRawPath.c_str(),
                        stableName.c_str(),
                        NULL)) {
                    // clang-format on
                    PLOG(ERROR) << "Failed to exec";
                }
            } else {
                // clang-format off
                if (execl(kSdcardFsPath, kSdcardFsPath,
                        "-u", "1023", // AID_MEDIA_RW
                        "-g", "1023", // AID_MEDIA_RW
                        "-U", std::to_string(getMountUserId()).c_str(),
                        // HUANGLONG modify begin
                        // add write permission for external storage partition
                        "-w",
                        // HUANGLONG modify end
                        mRawPath.c_str(),
                        stableName.c_str(),
                        NULL)) {
                    // clang-format on
                    PLOG(ERROR) << "Failed to exec";
                }
            }

            LOG(ERROR) << "sdcardfs exiting";
            _exit(1);
        }

        if (sdcardFsPid == -1) {
            PLOG(ERROR) << getId() << " failed to fork";
            return -errno;
        }

        nsecs_t start = systemTime(SYSTEM_TIME_BOOTTIME);
        while (before == GetDevice(mSdcardFsFull)) {
            LOG(DEBUG) << "Waiting for sdcardfs to spin up...";
            usleep(50000);  // 50ms

            nsecs_t now = systemTime(SYSTEM_TIME_BOOTTIME);
            if (nanoseconds_to_milliseconds(now - start) > 5000) {
                LOG(WARNING) << "Timed out while waiting for sdcardfs to spin up";
                return -ETIMEDOUT;
            }
        }
        /* sdcardfs will have exited already. The filesystem will still be running */
        TEMP_FAILURE_RETRY(waitpid(sdcardFsPid, nullptr, 0));
    }

    // We need to mount FUSE *after* sdcardfs, since the FUSE daemon may depend
    // on sdcardfs being up.
    LOG(INFO) << "Mounting public fuse volume";
    android::base::unique_fd fd;
    int user_id = getMountUserId();
    int result = MountUserFuse(user_id, getInternalPath(), stableName, &fd);

    if (result != 0) {
        LOG(ERROR) << "Failed to mount public fuse volume";
        doUnmount();
        return -result;
    }

    mFuseMounted = true;
    auto callback = getMountCallback();
    if (callback) {
        bool is_ready = false;
        callback->onVolumeChecking(std::move(fd), getPath(), getInternalPath(), &is_ready);
        if (!is_ready) {
            LOG(ERROR) << "Failed to complete public volume mount";
            doUnmount();
            return -EIO;
        }
    }

    ConfigureReadAheadForFuse(GetFuseMountPathForUser(user_id, stableName), 256u);

    // See comment in model/EmulatedVolume.cpp
    ConfigureMaxDirtyRatioForFuse(GetFuseMountPathForUser(user_id, stableName), 40u);

    return OK;
}

status_t PublicVolume::doUnmount() {
    // Unmount the storage before we kill the FUSE process. If we kill
    // the FUSE process first, most file system operations will return
    // ENOTCONN until the unmount completes. This is an exotic and unusual
    // error code and might cause broken behaviour in applications.
    KillProcessesUsingPath(getPath());

    if (mFuseMounted) {
        // Use UUID as stable name, if available
        std::string stableName = getId();
        if (!mFsUuid.empty()) {
            stableName = mFsUuid;
        }
        // HUANGLONG modify begin
        // fix usb cannot unmount issue
        stableName = mStableName;
        LOG(INFO) << "mStableName: " << mStableName;
        mStableName.clear();
        // HUANGLONG modify end
        if (UnmountUserFuse(getMountUserId(), getInternalPath(), stableName) != OK) {
            PLOG(INFO) << "UnmountUserFuse failed on public fuse volume";
            return -errno;
        }

        mFuseMounted = false;
    }

    ForceUnmount(kAsecPath);
    if (mUseSdcardFs) {
        ForceUnmount(mSdcardFsDefault);
        ForceUnmount(mSdcardFsRead);
        ForceUnmount(mSdcardFsWrite);
        ForceUnmount(mSdcardFsFull);

        rmdir(mSdcardFsDefault.c_str());
        rmdir(mSdcardFsRead.c_str());
        rmdir(mSdcardFsWrite.c_str());
        rmdir(mSdcardFsFull.c_str());

        mSdcardFsDefault.clear();
        mSdcardFsRead.clear();
        mSdcardFsWrite.clear();
        mSdcardFsFull.clear();
    }
    ForceUnmount(mRawPath);
    rmdir(mRawPath.c_str());
    mRawPath.clear();

    return OK;
}

status_t PublicVolume::doFormat(const std::string& fsType) {
    bool useVfat = vfat::IsSupported();
    bool useExfat = exfat::IsSupported();
    status_t res = OK;

    // Resolve the target filesystem type
    if (fsType == "auto" && useVfat && useExfat) {
        uint64_t size = 0;

        res = GetBlockDevSize(mDevPath, &size);
        if (res != OK) {
            LOG(ERROR) << "Couldn't get device size " << mDevPath;
            return res;
        }

        // If both vfat & exfat are supported use exfat for SDXC (>~32GiB) cards
        if (size > 32896LL * 1024 * 1024) {
            useVfat = false;
        } else {
            useExfat = false;
        }
    } else if (fsType == "vfat") {
        useExfat = false;
    } else if (fsType == "exfat") {
        useVfat = false;
    }

    if (!useVfat && !useExfat) {
        LOG(ERROR) << "Unsupported filesystem " << fsType;
        return -EINVAL;
    }

    if (WipeBlockDevice(mDevPath) != OK) {
        LOG(WARNING) << getId() << " failed to wipe";
    }

    if (useVfat) {
        res = vfat::Format(mDevPath, 0);
    } else if (useExfat) {
        res = exfat::Format(mDevPath);
    }

    if (res != OK) {
        LOG(ERROR) << getId() << " failed to format";
        res = -errno;
    }

    return res;
}

}  // namespace vold
}  // namespace android