/*
   Copyright (C) 2000-2002 Stephan Kulow <coolo@kde.org>
   Copyright (C) 2000-2002 David Faure <faure@kde.org>
   Copyright (C) 2000-2002 Waldo Bastian <bastian@kde.org>
   Copyright (C) 2006 Allan Sandfeld Jensen <sandfeld@kde.org>
   Copyright (C) 2007 Thiago Macieira <thiago@kde.org>
   Copyright (C) 2007 Christian Ehrlicher <ch.ehrlicher@gmx.de>

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License (LGPL) as published by the Free Software Foundation;
   either version 2 of the License, or (at your option) any later
   version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public License
   along with this library; see the file COPYING.LIB.  If not, write to
   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.
*/

#include "file.h"

#include <config-kioslave-file.h>

#include <QFile>
#include <QDir>
#include <qplatformdefs.h>
#include <QStandardPaths>
#include <QThread>

#include <QDebug>
#include <kconfiggroup.h>
#include <klocalizedstring.h>
#include <kmountpoint.h>

#include <errno.h>
#if HAVE_SYS_XATTR_H
#include <sys/xattr.h>
#include <stdint.h>
#endif
#include <utime.h>

#include <KAuth>
#include <KRandom>

#include "fdreceiver.h"
#include "statjob.h"

#if HAVE_STATX
#include <sys/stat.h>
#include <sys/sysmacros.h> // for makedev()
#endif

//sendfile has different semantics in different platforms
#if HAVE_SENDFILE && defined Q_OS_LINUX
#define USE_SENDFILE 1
#include <sys/sendfile.h>
#endif

using namespace KIO;

/* 512 kB */
#define MAX_IPC_SIZE (1024*512)

static bool
same_inode(const QT_STATBUF &src, const QT_STATBUF &dest)
{
    if (src.st_ino == dest.st_ino &&
            src.st_dev == dest.st_dev) {
        return true;
    }

    return false;
}

static const QString socketPath()
{
    const QString runtimeDir = QStandardPaths::writableLocation(QStandardPaths::RuntimeLocation);
    return QStringLiteral("%1/filehelper%2%3").arg(runtimeDir, KRandom::randomString(6)).arg(getpid());
}

static QString actionDetails(ActionType actionType, const QVariantList &args)
{
    QString action, detail;
    switch (actionType) {
    case CHMOD:
        action = i18n("Change File Permissions");
        detail = i18n("New Permissions: %1", args[1].toInt());
        break;
    case CHOWN:
        action = i18n("Change File Owner");
        detail = i18n("New Owner: UID=%1, GID=%2", args[1].toInt(), args[2].toInt());
        break;
    case DEL:
        action = i18n("Remove File");
        break;
    case RMDIR:
        action = i18n("Remove Directory");
        break;
    case MKDIR:
        action = i18n("Create Directory");
        detail = i18n("Directory Permissions: %1", args[1].toInt());
        break;
    case OPEN:
        action = i18n("Open File");
        break;
    case OPENDIR:
        action = i18n("Open Directory");
        break;
    case RENAME:
        action = i18n("Rename");
        detail = i18n("New Filename: %1", args[1].toString());
        break;
    case SYMLINK:
        action = i18n("Create Symlink");
        detail = i18n("Target: %1", args[1].toString());
        break;
    case UTIME:
        action = i18n("Change Timestamp");
        break;
    default:
        action = i18n("Unknown Action");
        break;
    }

    const QString metadata = i18n("Action: %1\n"
                                  "Source: %2\n"
                                  "%3", action, args[0].toString(), detail);
    return metadata;
}

bool FileProtocol::privilegeOperationUnitTestMode()
{
    return (metaData(QStringLiteral("UnitTesting")) == QLatin1String("true"))
            && (requestPrivilegeOperation(QStringLiteral("Test Call")) == KIO::OperationAllowed);
}

/*************************************
 *
 * ACL handling helpers
 *
 *************************************/
#if HAVE_POSIX_ACL

static QString aclToText(acl_t acl)
{
    ssize_t size = 0;
    char *txt = acl_to_text(acl, &size);
    const QString ret = QString::fromLatin1(txt, size);
    acl_free(txt);
    return ret;
}

bool FileProtocol::isExtendedACL(acl_t acl)
{
    return (acl_equiv_mode(acl, nullptr) != 0);
}

static void appendACLAtoms(const QByteArray &path, UDSEntry &entry, mode_t type)
{
    // first check for a noop
    if (acl_extended_file(path.data()) == 0) {
        return;
    }

    acl_t acl = nullptr;
    acl_t defaultAcl = nullptr;
    bool isDir = (type & QT_STAT_MASK) == QT_STAT_DIR;
    // do we have an acl for the file, and/or a default acl for the dir, if it is one?
    acl = acl_get_file(path.data(), ACL_TYPE_ACCESS);
    /* Sadly libacl does not provided a means of checking for extended ACL and default
     * ACL separately. Since a directory can have both, we need to check again. */
    if (isDir) {
        if (acl) {
            if (!FileProtocol::isExtendedACL(acl)) {
                acl_free(acl);
                acl = nullptr;
            }
        }
        defaultAcl = acl_get_file(path.data(), ACL_TYPE_DEFAULT);
    }
    if (acl || defaultAcl) {
        // qDebug() << path.constData() << "has extended ACL entries";
        entry.fastInsert(KIO::UDSEntry::UDS_EXTENDED_ACL, 1);

        if (acl) {
            const QString str = aclToText(acl);
            entry.fastInsert(KIO::UDSEntry::UDS_ACL_STRING, str);
            // qDebug() << path.constData() << "ACL:" << str;
            acl_free(acl);
        }

        if (defaultAcl) {
            const QString str = aclToText(defaultAcl);
            entry.fastInsert(KIO::UDSEntry::UDS_DEFAULT_ACL_STRING, str);
            // qDebug() << path.constData() << "DEFAULT ACL:" << str;
            acl_free(defaultAcl);
        }
    }
}
#endif

static QHash<KUserId, QString> staticUserCache;
static QHash<KGroupId, QString> staticGroupCache;

static QString getUserName(KUserId uid)
{
    if (Q_UNLIKELY(!uid.isValid())) {
        return QString();
    }
    auto it = staticUserCache.find(uid);
    if (it == staticUserCache.end()) {
        KUser user(uid);
        QString name = user.loginName();
        if (name.isEmpty()) {
            name = uid.toString();
        }
        it = staticUserCache.insert(uid, name);
    }
    return *it;
}

static QString getGroupName(KGroupId gid)
{
    if (Q_UNLIKELY(!gid.isValid())) {
        return QString();
    }
    auto it = staticGroupCache.find(gid);
    if (it == staticGroupCache.end()) {
        KUserGroup group(gid);
        QString name = group.name();
        if (name.isEmpty()) {
            name = gid.toString();
        }
        it = staticGroupCache.insert(gid, name);
    }
    return *it;
}

#if HAVE_STATX
// statx syscall is available
inline int LSTAT(const char* path, struct statx * buff, KIO::StatDetails details) {
    uint32_t mask = 0;
    if (details & KIO::StatBasic) {
        // filename, access, type, size, linkdest
        mask |= STATX_SIZE | STATX_TYPE;
    }
    if (details & KIO::StatUser) {
        // uid, gid
        mask |= STATX_UID | STATX_GID;
    }
    if (details & KIO::StatTime) {
        // atime, mtime, btime
        mask |= STATX_ATIME | STATX_MTIME | STATX_BTIME;
    }
    if (details & KIO::StatInode) {
        // dev, inode
        mask |= STATX_INO;
    }
    return statx(AT_FDCWD, path, AT_SYMLINK_NOFOLLOW, mask, buff);
}
inline int STAT(const char* path, struct statx * buff, KIO::StatDetails details) {
    uint32_t mask = 0;
    // KIO::StatAcl needs type
    if (details & (KIO::StatBasic | KIO::StatAcl | KIO::StatResolveSymlink)) {
        // filename, access, type
        mask |= STATX_TYPE;
    }
    if (details & (KIO::StatBasic | KIO::StatResolveSymlink)) {
        // size, linkdest
        mask |= STATX_SIZE;
    }
    if (details & KIO::StatUser) {
        // uid, gid
        mask |= STATX_UID | STATX_GID;
    }
    if (details & KIO::StatTime) {
        // atime, mtime, btime
        mask |= STATX_ATIME | STATX_MTIME | STATX_BTIME;
    }
    // KIO::Inode is ignored as when STAT is called, the entry inode field has already been filled
    return statx(AT_FDCWD, path, AT_STATX_SYNC_AS_STAT, mask, buff);
}
inline static uint16_t stat_mode(struct statx &buf) { return buf.stx_mode; }
inline static dev_t stat_dev(struct statx &buf) { return makedev(buf.stx_dev_major, buf.stx_dev_minor); }
inline static uint64_t stat_ino(struct statx &buf) { return buf.stx_ino; }
inline static uint64_t stat_size(struct statx &buf) { return buf.stx_size; }
inline static uint32_t stat_uid(struct statx &buf) { return buf.stx_uid; }
inline static uint32_t stat_gid(struct statx &buf) { return buf.stx_gid; }
inline static int64_t stat_atime(struct statx &buf) { return buf.stx_atime.tv_sec; }
inline static int64_t stat_mtime(struct statx &buf) { return buf.stx_mtime.tv_sec; }
#else
// regular stat struct
inline int LSTAT(const char* path, QT_STATBUF * buff, KIO::StatDetails details) {
    Q_UNUSED(details)
    return QT_LSTAT(path, buff);
}
inline int STAT(const char* path, QT_STATBUF * buff, KIO::StatDetails details) {
    Q_UNUSED(details)
    return QT_STAT(path, buff);
}
inline static mode_t stat_mode(QT_STATBUF &buf) { return buf.st_mode; }
inline static dev_t stat_dev(QT_STATBUF &buf) { return buf.st_dev; }
inline static ino_t stat_ino(QT_STATBUF &buf) { return buf.st_ino; }
inline static off_t stat_size(QT_STATBUF &buf) { return buf.st_size; }
inline static uid_t stat_uid(QT_STATBUF &buf) { return buf.st_uid; }
inline static gid_t stat_gid(QT_STATBUF &buf) { return buf.st_gid; }
inline static time_t stat_atime(QT_STATBUF &buf) { return buf.st_atime; }
inline static time_t stat_mtime(QT_STATBUF &buf) { return buf.st_mtime; }
#endif

static bool createUDSEntry(const QString &filename, const QByteArray &path, UDSEntry &entry,
                                  KIO::StatDetails details)
{
    assert(entry.count() == 0); // by contract :-)
    int entries = 0;
    if (details & KIO::StatBasic) {
        // filename, access, type, size, linkdest
        entries += 5;
    }
    if (details & KIO::StatUser) {
        // uid, gid
        entries += 2;
    }
    if (details & KIO::StatTime) {
        // atime, mtime, btime
        entries += 3;
    }
    if (details & KIO::StatAcl) {
        // acl data
        entries += 3;
    }
    if (details & KIO::StatInode) {
        // dev, inode
        entries += 2;
    }
    entry.reserve(entries);

    if (details & KIO::StatBasic) {
        entry.fastInsert(KIO::UDSEntry::UDS_NAME, filename);
    }

    bool isBrokenSymLink = false;
#if HAVE_POSIX_ACL
    QByteArray targetPath = path;
#endif

#if HAVE_STATX
    // statx syscall is available
    struct statx buff;
#else
    QT_STATBUF buff;
#endif

    if (LSTAT(path.data(), &buff, details) == 0)  {

        if ((stat_mode(buff) & QT_STAT_MASK) == QT_STAT_LNK) {

            QByteArray linkTargetBuffer;
            if (details & (KIO::StatBasic|KIO::StatResolveSymlink)) {

                // Use readlink on Unix because symLinkTarget turns relative targets into absolute (#352927)
                #if HAVE_STATX
                    size_t lowerBound = 256;
                    size_t higherBound = 1024;
                    uint64_t s = stat_size(buff);
                    if (s > SIZE_MAX) {
                        qCWarning(KIO_FILE) << "file size bigger than SIZE_MAX, too big for readlink use!" << path;
                        return false;
                    }
                    size_t size = static_cast<size_t>(s);
                    using SizeType = size_t;
                #else
                    off_t lowerBound = 256;
                    off_t higherBound = 1024;
                    off_t size = stat_size(buff);
                    using SizeType = off_t;
                #endif
                SizeType bufferSize = qBound(lowerBound, size +1, higherBound);
                linkTargetBuffer.resize(bufferSize);
                while (true) {
                    ssize_t n = readlink(path.constData(), linkTargetBuffer.data(), bufferSize);
                    if (n < 0 && errno != ERANGE) {
                        qCWarning(KIO_FILE) << "readlink failed!" << path;
                        return false;
                    } else if (n > 0 && static_cast<SizeType>(n) != bufferSize) {
                        // the buffer was not filled in the last iteration
                        // we are finished reading, break the loop
                        linkTargetBuffer.truncate(n);
                        break;
                    }
                    bufferSize *= 2;
                    linkTargetBuffer.resize(bufferSize);
                }
                const QString linkTarget = QFile::decodeName(linkTargetBuffer);
                entry.fastInsert(KIO::UDSEntry::UDS_LINK_DEST, linkTarget);
            }

            // A symlink
            if (details & KIO::StatResolveSymlink) {
                if (STAT(path.constData(), &buff, details) == -1) {
                    isBrokenSymLink = true;
                } else {
#if HAVE_POSIX_ACL
                    if (details & KIO::StatAcl) {
                        // valid symlink, will get the ACLs of the destination
                        targetPath = linkTargetBuffer;
                    }
#endif
                }
            }
        }
    } else {
        // qCWarning(KIO_FILE) << "lstat didn't work on " << path.data();
        return false;
    }

    mode_t type = 0;
    if (details & (KIO::StatBasic | KIO::StatAcl)) {
        mode_t access;
        signed long long size;
        if (isBrokenSymLink) {
            // It is a link pointing to nowhere
            type = S_IFMT - 1;
            access = S_IRWXU | S_IRWXG | S_IRWXO;
            size = 0LL;
        } else {
            type = stat_mode(buff) & S_IFMT; // extract file type
            access = stat_mode(buff) & 07777; // extract permissions
            size = stat_size(buff);
        }

        if (details & KIO::StatBasic) {
            entry.fastInsert(KIO::UDSEntry::UDS_FILE_TYPE, type);
            entry.fastInsert(KIO::UDSEntry::UDS_ACCESS, access);
            entry.fastInsert(KIO::UDSEntry::UDS_SIZE, size);
        }

#if HAVE_POSIX_ACL
        if (details & KIO::StatAcl) {
            /* Append an atom indicating whether the file has extended acl information
             * and if withACL is specified also one with the acl itself. If it's a directory
             * and it has a default ACL, also append that. */
            appendACLAtoms(targetPath, entry, type);
        }
#endif
    }

    if (details & KIO::StatUser) {
        entry.fastInsert(KIO::UDSEntry::UDS_USER, getUserName(KUserId(stat_uid(buff))));
        entry.fastInsert(KIO::UDSEntry::UDS_GROUP, getGroupName(KGroupId(stat_gid(buff))));
    }

    if (details & KIO::StatTime) {
        entry.fastInsert(KIO::UDSEntry::UDS_MODIFICATION_TIME, stat_mtime(buff));
        entry.fastInsert(KIO::UDSEntry::UDS_ACCESS_TIME, stat_atime(buff));

#ifdef st_birthtime
        /* For example FreeBSD's and NetBSD's stat contains a field for
         * the inode birth time: st_birthtime
         * This however only works on UFS and ZFS, and not, on say, NFS.
         * Instead of setting a bogus fallback like st_mtime, only use
         * it if it is greater than 0. */
        if (buff.st_birthtime > 0) {
            entry.fastInsert(KIO::UDSEntry::UDS_CREATION_TIME, buff.st_birthtime);
        }
#elif defined __st_birthtime
        /* As above, but OpenBSD calls it slightly differently. */
        if (buff.__st_birthtime > 0) {
            entry.fastInsert(KIO::UDSEntry::UDS_CREATION_TIME, buff.__st_birthtime);
        }
#elif HAVE_STATX
        /* And linux version using statx syscall */
        if (buff.stx_mask & STATX_BTIME) {
            entry.fastInsert(KIO::UDSEntry::UDS_CREATION_TIME, buff.stx_btime.tv_sec);
        }
#endif
    }

    if (details & KIO::StatInode) {
        entry.fastInsert(KIO::UDSEntry::UDS_DEVICE_ID, stat_dev(buff));
        entry.fastInsert(KIO::UDSEntry::UDS_INODE, stat_ino(buff));
    }

    return true;
}

PrivilegeOperationReturnValue FileProtocol::tryOpen(QFile &f, const QByteArray &path, int flags, int mode, int errcode)
{
    const QString sockPath = socketPath();
    FdReceiver fdRecv(QFile::encodeName(sockPath).toStdString());
    if (!fdRecv.isListening()) {
        return PrivilegeOperationReturnValue::failure(errcode);
    }

    QIODevice::OpenMode openMode;
    if (flags & O_RDONLY) {
        openMode |= QIODevice::ReadOnly;
    }
    if (flags & O_WRONLY || flags & O_CREAT) {
        openMode |= QIODevice::WriteOnly;
    }
    if (flags & O_RDWR) {
        openMode |= QIODevice::ReadWrite;
    }
    if (flags & O_TRUNC) {
        openMode |= QIODevice::Truncate;
    }
    if (flags & O_APPEND) {
        openMode |= QIODevice::Append;
    }

    if (auto err = execWithElevatedPrivilege(OPEN, {path, flags, mode, sockPath}, errcode)) {
        return err;
    } else {
        int fd = fdRecv.fileDescriptor();
        if (fd < 3 || !f.open(fd, openMode, QFileDevice::AutoCloseHandle)) {
            return PrivilegeOperationReturnValue::failure(errcode);
        }
    }
    return PrivilegeOperationReturnValue::success();
}

PrivilegeOperationReturnValue FileProtocol::tryChangeFileAttr(ActionType action, const QVariantList &args, int errcode)
{
    KAuth::Action execAction(QStringLiteral("org.kde.kio.file.exec"));
    execAction.setHelperId(QStringLiteral("org.kde.kio.file"));
    if (execAction.status() == KAuth::Action::AuthorizedStatus) {
        return execWithElevatedPrivilege(action, args, errcode);
    }
    return PrivilegeOperationReturnValue::failure(errcode);
}

void FileProtocol::copy(const QUrl &srcUrl, const QUrl &destUrl,
                        int _mode, JobFlags _flags)
{
    if (privilegeOperationUnitTestMode()) {
        finished();
        return;
    }

    // qDebug() << "copy(): " << srcUrl << " -> " << destUrl << ", mode=" << _mode;

    const QString src = srcUrl.toLocalFile();
    QString dest = destUrl.toLocalFile();
    QByteArray _src(QFile::encodeName(src));
    QByteArray _dest(QFile::encodeName(dest));
    QByteArray _dest_backup;

    QT_STATBUF buff_src;
#if HAVE_POSIX_ACL
    acl_t acl;
#endif
    if (QT_STAT(_src.data(), &buff_src) == -1) {
        if (errno == EACCES) {
            error(KIO::ERR_ACCESS_DENIED, src);
        } else {
            error(KIO::ERR_DOES_NOT_EXIST, src);
        }
        return;
    }

    if ((buff_src.st_mode & QT_STAT_MASK) == QT_STAT_DIR) {
        error(KIO::ERR_IS_DIRECTORY, src);
        return;
    }
    if (S_ISFIFO(buff_src.st_mode) || S_ISSOCK(buff_src.st_mode)) {
        error(KIO::ERR_CANNOT_OPEN_FOR_READING, src);
        return;
    }

    QT_STATBUF buff_dest;
    bool dest_exists = (QT_LSTAT(_dest.data(), &buff_dest) != -1);
    if (dest_exists) {
        if (same_inode(buff_dest, buff_src)) {
            error(KIO::ERR_IDENTICAL_FILES, dest);
            return;
        }

        if ((buff_dest.st_mode & QT_STAT_MASK) == QT_STAT_DIR) {
            error(KIO::ERR_DIR_ALREADY_EXIST, dest);
            return;
        }

        if (_flags & KIO::Overwrite) {
            // If the destination is a symlink and overwrite is TRUE,
            // remove the symlink first to prevent the scenario where
            // the symlink actually points to current source!
            if ((buff_dest.st_mode & QT_STAT_MASK) == QT_STAT_LNK) {
                //qDebug() << "copy(): LINK DESTINATION";
                if (!QFile::remove(dest)) {
                    if (auto err = execWithElevatedPrivilege(DEL, {_dest}, errno)) {
                        if (!err.wasCanceled()) {
                            error(KIO::ERR_CANNOT_DELETE_ORIGINAL, dest);
                        }
                        return;
                    }
                }
            } else if ((buff_dest.st_mode & QT_STAT_MASK) == QT_STAT_REG) {
                _dest_backup = _dest;
                dest.append(QStringLiteral(".part"));
                _dest = QFile::encodeName(dest);
            }
        } else {
            error(KIO::ERR_FILE_ALREADY_EXIST, dest);
            return;
        }
    }

    QFile src_file(src);
    if (!src_file.open(QIODevice::ReadOnly)) {
        if (auto err = tryOpen(src_file, _src, O_RDONLY, S_IRUSR, errno)) {
            if (!err.wasCanceled()) {
                error(KIO::ERR_CANNOT_OPEN_FOR_READING, src);
            }
            return;
        }
    }

#if HAVE_FADVISE
    posix_fadvise(src_file.handle(), 0, 0, POSIX_FADV_SEQUENTIAL);
#endif

    QFile dest_file(dest);
    if (!dest_file.open(QIODevice::Truncate | QIODevice::WriteOnly)) {
        if (auto err = tryOpen(dest_file, _dest, O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR, errno)) {
            if (!err.wasCanceled()) {
                // qDebug() << "###### COULD NOT WRITE " << dest;
                if (err == EACCES) {
                    error(KIO::ERR_WRITE_ACCESS_DENIED, dest);
                } else {
                    error(KIO::ERR_CANNOT_OPEN_FOR_WRITING, dest);
                }
            }
            src_file.close();
            return;
        }
    }

    // nobody shall be allowed to peek into the file during creation
    // Note that error handling is omitted for this call, we don't want to error on e.g. VFAT
    dest_file.setPermissions(QFileDevice::ReadOwner | QFileDevice::WriteOwner);

#if HAVE_FADVISE
    posix_fadvise(dest_file.handle(), 0, 0, POSIX_FADV_SEQUENTIAL);
#endif

#if HAVE_POSIX_ACL
    acl = acl_get_fd(src_file.handle());
    if (acl && !isExtendedACL(acl)) {
        // qDebug() << _dest.data() << " doesn't have extended ACL";
        acl_free(acl);
        acl = nullptr;
    }
#endif
    totalSize(buff_src.st_size);

    KIO::filesize_t processed_size = 0;
    char buffer[ MAX_IPC_SIZE ];
    ssize_t n = 0;
#ifdef USE_SENDFILE
    bool use_sendfile = true;
#endif
    bool existing_dest_delete_attempted = false;
    while (!wasKilled()) {

        if (testMode && dest_file.fileName().contains(QLatin1String("slow"))) {
            QThread::usleep(500);
        }

#ifdef USE_SENDFILE
        if (use_sendfile) {
            off_t sf = processed_size;
            n = ::sendfile(dest_file.handle(), src_file.handle(), &sf, MAX_IPC_SIZE);
            processed_size = sf;
            if (n == -1 && (errno == EINVAL || errno == ENOSYS)) {     //not all filesystems support sendfile()
                // qDebug() << "sendfile() not supported, falling back ";
                use_sendfile = false;
            }
        }
        if (!use_sendfile)
#endif
            n = ::read(src_file.handle(), buffer, MAX_IPC_SIZE);

        if (n == -1) {
            if (errno == EINTR) {
                continue;
            }
#ifdef USE_SENDFILE
            if (use_sendfile) {
                // qDebug() << "sendfile() error:" << strerror(errno);
                if (errno == ENOSPC) { // disk full
                    if (!_dest_backup.isEmpty() && !existing_dest_delete_attempted) {
                        ::unlink(_dest_backup.constData());
                        existing_dest_delete_attempted = true;
                        continue;
                    }
                    error(KIO::ERR_DISK_FULL, dest);
                } else {
                    error(KIO::ERR_SLAVE_DEFINED,
                          i18n("Cannot copy file from %1 to %2. (Errno: %3)",
                               src, dest, errno));
                }
            } else
#endif
                error(KIO::ERR_CANNOT_READ, src);
            src_file.close();
            dest_file.close();
#if HAVE_POSIX_ACL
            if (acl) {
                acl_free(acl);
            }
#endif
            if (!QFile::remove(dest)) {  // don't keep partly copied file
                execWithElevatedPrivilege(DEL, {_dest}, errno);
            }
            return;
        }
        if (n == 0) {
            break;    // Finished
        }
#ifdef USE_SENDFILE
        if (!use_sendfile) {
#endif
            if (dest_file.write(buffer, n) != n) {
                if (dest_file.error() == QFileDevice::ResourceError) {  // disk full
                    if (!_dest_backup.isEmpty() && !existing_dest_delete_attempted) {
                        ::unlink(_dest_backup.constData());
                        existing_dest_delete_attempted = true;
                        continue;
                    }
                    error(KIO::ERR_DISK_FULL, dest);
                } else {
                    qCWarning(KIO_FILE) << "Couldn't write[2]. Error:" << dest_file.errorString();
                    error(KIO::ERR_CANNOT_WRITE, dest);
                }
#if HAVE_POSIX_ACL
                if (acl) {
                    acl_free(acl);
                }
#endif
                if (!QFile::remove(dest)) {  // don't keep partly copied file
                    execWithElevatedPrivilege(DEL, {_dest}, errno);
                }
                return;
            }
            processed_size += n;
#ifdef USE_SENDFILE
        }
#endif
        processedSize(processed_size);
    }

    src_file.close();
    dest_file.close();

    if (wasKilled()) {
        qCDebug(KIO_FILE) << "Clean dest file after ioslave was killed:" << dest;
        if (!QFile::remove(dest)) {  // don't keep partly copied file
            execWithElevatedPrivilege(DEL, {_dest}, errno);
        }
        error(KIO::ERR_USER_CANCELED, dest);
        return;
    }

    if (dest_file.error() != QFile::NoError) {
        qCWarning(KIO_FILE) << "Error when closing file descriptor[2]:" << dest_file.errorString();
        error(KIO::ERR_CANNOT_WRITE, dest);
#if HAVE_POSIX_ACL
        if (acl) {
            acl_free(acl);
        }
#endif
        if (!QFile::remove(dest)) {  // don't keep partly copied file
            execWithElevatedPrivilege(DEL, {_dest}, errno);
        }
        return;
    }

    // set final permissions
    // if no special mode given, preserve the mode from the sourcefile
    if (_mode == -1) {
        _mode = buff_src.st_mode;
    }

    if ((::chmod(_dest.data(), _mode) != 0)
#if HAVE_POSIX_ACL
        || (acl && acl_set_file(_dest.data(), ACL_TYPE_ACCESS, acl) != 0)
#endif
       ) {
        const int errCode = errno;
        KMountPoint::Ptr mp = KMountPoint::currentMountPoints().findByPath(dest);
        // Eat the error if the filesystem apparently doesn't support chmod.
        // This test isn't fullproof though, vboxsf (VirtualBox shared folder) supports
        // chmod if the host is Linux, and doesn't if the host is Windows. Hard to detect.
        if (mp && mp->testFileSystemFlag(KMountPoint::SupportsChmod)) {
            if (tryChangeFileAttr(CHMOD, {_dest, _mode}, errCode)) {
                qCWarning(KIO_FILE) << "Could not change permissions for" << dest;
            }
        }
    }
#if HAVE_POSIX_ACL
    if (acl) {
        acl_free(acl);
    }
#endif

    // preserve ownership
    if (::chown(_dest.data(), -1 /*keep user*/, buff_src.st_gid) == 0) {
        // as we are the owner of the new file, we can always change the group, but
        // we might not be allowed to change the owner
        (void)::chown(_dest.data(), buff_src.st_uid, -1 /*keep group*/);
    } else {
        if (tryChangeFileAttr(CHOWN, {_dest, buff_src.st_uid, buff_src.st_gid}, errno)) {
            qCWarning(KIO_FILE) << "Couldn't preserve group for" << dest;
        }
    }

    // copy access and modification time
    struct utimbuf ut;
    ut.actime = buff_src.st_atime;
    ut.modtime = buff_src.st_mtime;
    if (::utime(_dest.data(), &ut) != 0) {
        if (tryChangeFileAttr(UTIME, {_dest, qint64(ut.actime), qint64(ut.modtime)}, errno)) {
            qCWarning(KIO_FILE) << "Couldn't preserve access and modification time for" << dest;
        }
    }

    if (!_dest_backup.isEmpty()) {
        if (::unlink(_dest_backup.constData()) == -1) {
            qCWarning(KIO_FILE) << "Couldn't remove original dest" <<  _dest_backup << "(" << strerror(errno) << ")";
        }

        if (::rename(_dest.constData(), _dest_backup.constData()) == -1) {
            qCWarning(KIO_FILE) << "Couldn't rename" << _dest << "to" << _dest_backup << "(" << strerror(errno) << ")";
        }
    }

    processedSize(buff_src.st_size);
    finished();
}

static bool isLocalFileSameHost(const QUrl &url)
{
    if (!url.isLocalFile()) {
        return false;
    }

    if (url.host().isEmpty() || (url.host() == QLatin1String("localhost"))) {
        return true;
    }

    char hostname[ 256 ];
    hostname[ 0 ] = '\0';
    if (!gethostname(hostname, 255)) {
        hostname[sizeof(hostname) - 1] = '\0';
    }

    return (QString::compare(url.host(), QLatin1String(hostname), Qt::CaseInsensitive) == 0);
}

#if HAVE_SYS_XATTR_H
static bool isNtfsHidden(const QString &filename)
{
    constexpr auto attrName = "system.ntfs_attrib_be";
    const auto filenameEncoded = QFile::encodeName(filename);

    uint32_t intAttr = 0;
    constexpr size_t xattr_size = sizeof(intAttr);
    char strAttr[xattr_size];
#ifdef Q_OS_MACOS
    auto length = getxattr(filenameEncoded.data(), attrName, strAttr, xattr_size, 0, XATTR_NOFOLLOW);
#else
    auto length = getxattr(filenameEncoded.data(), attrName, strAttr, xattr_size);
#endif
    if (length <= 0) {
        return false;
    }

    char *c = strAttr;
    for (decltype(length) n = 0; n < length; ++n, ++c) {
        intAttr <<= 8;
        intAttr |= static_cast<uchar>(*c);
    }

    constexpr auto FILE_ATTRIBUTE_HIDDEN = 0x2u;
    return static_cast<bool>(intAttr & FILE_ATTRIBUTE_HIDDEN);
}
#endif


void FileProtocol::listDir(const QUrl &url)
{
    if (!isLocalFileSameHost(url)) {
        QUrl redir(url);
        redir.setScheme(configValue(QStringLiteral("DefaultRemoteProtocol"), QStringLiteral("smb")));
        redirection(redir);
        // qDebug() << "redirecting to " << redir;
        finished();
        return;
    }
    const QString path(url.toLocalFile());
    const QByteArray _path(QFile::encodeName(path));
    DIR *dp = opendir(_path.data());
    if (dp == nullptr) {
        switch (errno) {
        case ENOENT:
            error(KIO::ERR_DOES_NOT_EXIST, path);
            return;
        case ENOTDIR:
            error(KIO::ERR_IS_FILE, path);
            break;
#ifdef ENOMEDIUM
        case ENOMEDIUM:
            error(ERR_SLAVE_DEFINED,
                  i18n("No media in device for %1", path));
            break;
#endif
        default:
            error(KIO::ERR_CANNOT_ENTER_DIRECTORY, path);
            break;
        }
        return;
    }

    /* set the current dir to the path to speed up
       in not having to pass an absolute path.
       We restore the path later to get out of the
       path - the kernel wouldn't unmount or delete
       directories we keep as active directory. And
       as the slave runs in the background, it's hard
       to see for the user what the problem would be */
    const QString pathBuffer(QDir::currentPath());
    if (!QDir::setCurrent(path)) {
        closedir(dp);
        error(ERR_CANNOT_ENTER_DIRECTORY, path);
        return;
    }

    const KIO::StatDetails details = getStatDetails();
    //qDebug() << "========= LIST " << url << "details=" << details << " =========";
    UDSEntry entry;

#ifndef HAVE_DIRENT_D_TYPE
    QT_STATBUF st;
#endif
    QT_DIRENT *ep;
    while ((ep = QT_READDIR(dp)) != nullptr) {
        entry.clear();

        const QString filename = QFile::decodeName(ep->d_name);

        /*
         * details == 0 (if statement) is the fast code path.
         * We only get the file name and type. After that we emit
         * the result.
         *
         * The else statement is the slow path that requests all
         * file information in file.cpp. It executes a stat call
         * for every entry thus becoming slower.
         *
         */
        if (details == KIO::StatBasic) {
            entry.fastInsert(KIO::UDSEntry::UDS_NAME, filename);
#ifdef HAVE_DIRENT_D_TYPE
            entry.fastInsert(KIO::UDSEntry::UDS_FILE_TYPE,
                         (ep->d_type == DT_DIR) ? S_IFDIR : S_IFREG);
            const bool isSymLink = (ep->d_type == DT_LNK);
#else
            // oops, no fast way, we need to stat (e.g. on Solaris)
            if (QT_LSTAT(ep->d_name, &st) == -1) {
                continue; // how can stat fail?
            }
            entry.fastInsert(KIO::UDSEntry::UDS_FILE_TYPE,
                         ((st.st_mode & QT_STAT_MASK) == QT_STAT_DIR) ? S_IFDIR : S_IFREG);
            const bool isSymLink = ((st.st_mode & QT_STAT_MASK) == QT_STAT_LNK);
#endif
            if (isSymLink) {
                // for symlinks obey the UDSEntry contract and provide UDS_LINK_DEST
                // even if we don't know the link dest (and DeleteJob doesn't care...)
                entry.fastInsert(KIO::UDSEntry::UDS_LINK_DEST, QStringLiteral("Dummy Link Target"));
            }
            listEntry(entry);

        } else {
            if (createUDSEntry(filename, QByteArray(ep->d_name), entry, details)) {
#if HAVE_SYS_XATTR_H
                if (isNtfsHidden(filename)) {
                    bool ntfsHidden = true;

                    // Bug 392913: NTFS root volume is always "hidden", ignore this
                    if (ep->d_type == DT_DIR || ep->d_type == DT_UNKNOWN || ep->d_type == DT_LNK) {
                        const QString fullFilePath = QDir(filename).canonicalPath();
                        auto mountPoint = KMountPoint::currentMountPoints().findByPath(fullFilePath);
                        if (mountPoint && mountPoint->mountPoint() == fullFilePath) {
                            ntfsHidden = false;
                        }
                    }

                    if (ntfsHidden) {
                        entry.fastInsert(KIO::UDSEntry::UDS_HIDDEN, 1);
                    }
                }
#endif
                listEntry(entry);
            }
        }
    }

    closedir(dp);

    // Restore the path
    QDir::setCurrent(pathBuffer);

    finished();
}

void FileProtocol::rename(const QUrl &srcUrl, const QUrl &destUrl,
                          KIO::JobFlags _flags)
{
    char off_t_should_be_64_bits[sizeof(off_t) >= 8 ? 1 : -1]; (void) off_t_should_be_64_bits;
    const QString src = srcUrl.toLocalFile();
    const QString dest = destUrl.toLocalFile();
    const QByteArray _src(QFile::encodeName(src));
    const QByteArray _dest(QFile::encodeName(dest));
    QT_STATBUF buff_src;
    if (QT_LSTAT(_src.data(), &buff_src) == -1) {
        if (errno == EACCES) {
            error(KIO::ERR_ACCESS_DENIED, src);
        } else {
            error(KIO::ERR_DOES_NOT_EXIST, src);
        }
        return;
    }

    QT_STATBUF buff_dest;
    // stat symlinks here (lstat, not stat), to avoid ERR_IDENTICAL_FILES when replacing symlink
    // with its target (#169547)
    bool dest_exists = (QT_LSTAT(_dest.data(), &buff_dest) != -1);
    if (dest_exists) {
        if (same_inode(buff_dest, buff_src)) {
            error(KIO::ERR_IDENTICAL_FILES, dest);
            return;
        }

        if ((buff_dest.st_mode & QT_STAT_MASK) == QT_STAT_DIR) {
            error(KIO::ERR_DIR_ALREADY_EXIST, dest);
            return;
        }

        if (!(_flags & KIO::Overwrite)) {
            error(KIO::ERR_FILE_ALREADY_EXIST, dest);
            return;
        }
    }

    if (::rename(_src.data(), _dest.data())) {
        if (auto err = execWithElevatedPrivilege(RENAME, {_src, _dest}, errno)) {
            if (!err.wasCanceled()) {
                if ((err == EACCES) || (err == EPERM)) {
                    error(KIO::ERR_WRITE_ACCESS_DENIED, dest);
                } else if (err == EXDEV) {
                    error(KIO::ERR_UNSUPPORTED_ACTION, QStringLiteral("rename"));
                } else if (err == EROFS) { // The file is on a read-only filesystem
                    error(KIO::ERR_CANNOT_DELETE, src);
                } else {
                    error(KIO::ERR_CANNOT_RENAME, src);
                }
            }
            return;
        }
    }

    finished();
}

void FileProtocol::symlink(const QString &target, const QUrl &destUrl, KIO::JobFlags flags)
{
    const QString dest = destUrl.toLocalFile();
    // Assume dest is local too (wouldn't be here otherwise)
    if (::symlink(QFile::encodeName(target).constData(), QFile::encodeName(dest).constData()) == -1) {
        // Does the destination already exist ?
        if (errno == EEXIST) {
            if ((flags & KIO::Overwrite)) {
                // Try to delete the destination
                if (unlink(QFile::encodeName(dest).constData()) != 0) {
                    if (auto err = execWithElevatedPrivilege(DEL, {dest}, errno)) {
                        if (!err.wasCanceled()) {
                            error(KIO::ERR_CANNOT_DELETE, dest);
                        }
                        return;
                    }
                }
                // Try again - this won't loop forever since unlink succeeded
                symlink(target, destUrl, flags);
                return;
            } else {
                QT_STATBUF buff_dest;
                if (QT_LSTAT(QFile::encodeName(dest).constData(), &buff_dest) == 0 && ((buff_dest.st_mode & QT_STAT_MASK) == QT_STAT_DIR)) {
                    error(KIO::ERR_DIR_ALREADY_EXIST, dest);
                } else {
                    error(KIO::ERR_FILE_ALREADY_EXIST, dest);
                }
                return;
            }
        } else {
            if (auto err = execWithElevatedPrivilege(SYMLINK, {dest, target}, errno)) {
                if (!err.wasCanceled()) {
                    // Some error occurred while we tried to symlink
                    error(KIO::ERR_CANNOT_SYMLINK, dest);
                }
                return;
            }
        }
    }
    finished();
}

void FileProtocol::del(const QUrl &url, bool isfile)
{
    const QString path = url.toLocalFile();
    const QByteArray _path(QFile::encodeName(path));
    /*****
     * Delete files
     *****/

    if (isfile) {
        // qDebug() << "Deleting file "<< url;

        if (unlink(_path.data()) == -1) {
            if (auto err = execWithElevatedPrivilege(DEL, {_path}, errno)) {
                if (!err.wasCanceled()) {
                    if ((err == EACCES) || (err ==  EPERM)) {
                        error(KIO::ERR_ACCESS_DENIED, path);
                    } else if (err == EISDIR) {
                        error(KIO::ERR_IS_DIRECTORY, path);
                    } else {
                        error(KIO::ERR_CANNOT_DELETE, path);
                    }
                }
                return;
            }
        }
    } else {

        /*****
         * Delete empty directory
         *****/

        // qDebug() << "Deleting directory " << url;
        if (metaData(QStringLiteral("recurse")) == QLatin1String("true")) {
            if (!deleteRecursive(path)) {
                return;
            }
        }
        if (QT_RMDIR(_path.data()) == -1) {
            if (auto err = execWithElevatedPrivilege(RMDIR, {_path}, errno)) {
                if (!err.wasCanceled()) {
                    if ((err == EACCES) || (err == EPERM)) {
                        error(KIO::ERR_ACCESS_DENIED, path);
                    } else {
                        // qDebug() << "could not rmdir " << perror;
                        error(KIO::ERR_CANNOT_RMDIR, path);
                    }
                }
                return;
            }
        }
    }

    finished();
}

void FileProtocol::chown(const QUrl &url, const QString &owner, const QString &group)
{
    const QString path = url.toLocalFile();
    const QByteArray _path(QFile::encodeName(path));
    uid_t uid;
    gid_t gid;

    // get uid from given owner
    {
        struct passwd *p = ::getpwnam(owner.toLocal8Bit().constData());

        if (! p) {
            error(KIO::ERR_SLAVE_DEFINED,
                  i18n("Could not get user id for given user name %1", owner));
            return;
        }

        uid = p->pw_uid;
    }

    // get gid from given group
    {
        struct group *p = ::getgrnam(group.toLocal8Bit().constData());

        if (! p) {
            error(KIO::ERR_SLAVE_DEFINED,
                  i18n("Could not get group id for given group name %1", group));
            return;
        }

        gid = p->gr_gid;
    }

    if (::chown(_path.constData(), uid, gid) == -1) {
        if (auto err = execWithElevatedPrivilege(CHOWN, {_path, uid, gid}, errno)) {
            if (!err.wasCanceled()) {
                switch (err) {
                case EPERM:
                case EACCES:
                    error(KIO::ERR_ACCESS_DENIED, path);
                    break;
                case ENOSPC:
                    error(KIO::ERR_DISK_FULL, path);
                    break;
                default:
                    error(KIO::ERR_CANNOT_CHOWN, path);
                }
            }
        }
    } else {
        finished();
    }
}

KIO::StatDetails FileProtocol::getStatDetails()
{
    // takes care of converting old metadata details to new StatDetails
    // TODO KF6 : remove legacy "details" code path
    KIO::StatDetails details;
#if KIOCORE_BUILD_DEPRECATED_SINCE(5, 69)
    if (hasMetaData(QStringLiteral("statDetails"))) {
#endif
        const QString statDetails = metaData(QStringLiteral("statDetails"));
        details = statDetails.isEmpty() ? KIO::StatDefaultDetails : static_cast<KIO::StatDetails>(statDetails.toInt());
#if KIOCORE_BUILD_DEPRECATED_SINCE(5, 69)
    } else {
        const QString sDetails = metaData(QStringLiteral("details"));
        details = sDetails.isEmpty() ? KIO::StatDefaultDetails : KIO::detailsToStatDetails(sDetails.toInt());
    }
#endif
    return details;
}

void FileProtocol::stat(const QUrl &url)
{
    if (!isLocalFileSameHost(url)) {
        redirect(url);
        return;
    }

    /* directories may not have a slash at the end if
     * we want to stat() them; it requires that we
     * change into it .. which may not be allowed
     * stat("/is/unaccessible")  -> rwx------
     * stat("/is/unaccessible/") -> EPERM            H.Z.
     * This is the reason for the -1
     */
    const QString path(url.adjusted(QUrl::StripTrailingSlash).toLocalFile());
    const QByteArray _path(QFile::encodeName(path));

    const KIO::StatDetails details = getStatDetails();

    UDSEntry entry;
    if (!createUDSEntry(url.fileName(), _path, entry, details)) {
        error(KIO::ERR_DOES_NOT_EXIST, path);
        return;
    }
#if 0
///////// debug code
    MetaData::iterator it1 = mOutgoingMetaData.begin();
    for (; it1 != mOutgoingMetaData.end(); it1++) {
        // qDebug() << it1.key() << " = " << it1.data();
    }
/////////
#endif
    statEntry(entry);

    finished();
}

PrivilegeOperationReturnValue FileProtocol::execWithElevatedPrivilege(ActionType action, const QVariantList &args, int errcode)
{
    if (privilegeOperationUnitTestMode()) {
        return PrivilegeOperationReturnValue::success();
    }

    // temporarily disable privilege execution
    if (true) {
        return PrivilegeOperationReturnValue::failure(errcode);
    }

    if (!(errcode == EACCES || errcode == EPERM)) {
        return PrivilegeOperationReturnValue::failure(errcode);
    }

    const QString operationDetails = actionDetails(action, args);
    KIO::PrivilegeOperationStatus opStatus = requestPrivilegeOperation(operationDetails);
    if (opStatus != KIO::OperationAllowed) {
        if (opStatus == KIO::OperationCanceled) {
            error(KIO::ERR_USER_CANCELED, QString());
            return PrivilegeOperationReturnValue::canceled();
        }
        return PrivilegeOperationReturnValue::failure(errcode);
    }

    const QUrl targetUrl = QUrl::fromLocalFile(args.first().toString()); // target is always the first item.
    const bool useParent = action != CHOWN && action != CHMOD && action != UTIME;
    const QString targetPath = useParent ? targetUrl.adjusted(QUrl::RemoveFilename).toLocalFile() : targetUrl.toLocalFile();
    bool userIsOwner = QFileInfo(targetPath).ownerId() == getuid();
    if (action == RENAME) { // for rename check src and dest owner
        QString dest = QUrl(args[1].toString()).toLocalFile();
        userIsOwner = userIsOwner && QFileInfo(dest).ownerId() == getuid();
    }
    if (userIsOwner) {
        error(KIO::ERR_PRIVILEGE_NOT_REQUIRED, targetPath);
        return PrivilegeOperationReturnValue::canceled();
    }

    QByteArray helperArgs;
    QDataStream out(&helperArgs, QIODevice::WriteOnly);
    out << action;
    for (const QVariant &arg : args) {
        out << arg;
    }

    const QString actionId = QStringLiteral("org.kde.kio.file.exec");
    KAuth::Action execAction(actionId);
    execAction.setHelperId(QStringLiteral("org.kde.kio.file"));

    QVariantMap argv;
    argv.insert(QStringLiteral("arguments"), helperArgs);
    execAction.setArguments(argv);

    auto reply = execAction.execute();
    if (reply->exec()) {
        addTemporaryAuthorization(actionId);
        return PrivilegeOperationReturnValue::success();
    }

    return PrivilegeOperationReturnValue::failure(KIO::ERR_ACCESS_DENIED);
}

int FileProtocol::setACL(const char *path, mode_t perm, bool directoryDefault)
{
    int ret = 0;
#if HAVE_POSIX_ACL

    const QString ACLString = metaData(QStringLiteral("ACL_STRING"));
    const QString defaultACLString = metaData(QStringLiteral("DEFAULT_ACL_STRING"));
    // Empty strings mean leave as is
    if (!ACLString.isEmpty()) {
        acl_t acl = nullptr;
        if (ACLString == QLatin1String("ACL_DELETE")) {
            // user told us to delete the extended ACL, so let's write only
            // the minimal (UNIX permission bits) part
            acl = acl_from_mode(perm);
        }
        acl = acl_from_text(ACLString.toLatin1().constData());
        if (acl_valid(acl) == 0) {     // let's be safe
            ret = acl_set_file(path, ACL_TYPE_ACCESS, acl);
            // qDebug() << "Set ACL on:" << path << "to:" << aclToText(acl);
        }
        acl_free(acl);
        if (ret != 0) {
            return ret;    // better stop trying right away
        }
    }

    if (directoryDefault && !defaultACLString.isEmpty()) {
        if (defaultACLString == QLatin1String("ACL_DELETE")) {
            // user told us to delete the default ACL, do so
            ret += acl_delete_def_file(path);
        } else {
            acl_t acl = acl_from_text(defaultACLString.toLatin1().constData());
            if (acl_valid(acl) == 0) {     // let's be safe
                ret += acl_set_file(path, ACL_TYPE_DEFAULT, acl);
                // qDebug() << "Set Default ACL on:" << path << "to:" << aclToText(acl);
            }
            acl_free(acl);
        }
    }
#else
    Q_UNUSED(path);
    Q_UNUSED(perm);
    Q_UNUSED(directoryDefault);
#endif
    return ret;
}
