qt-creator/src/plugins/coreplugin/ssh/sftpchannel.cpp

/**************************************************************************
**
** This file is part of Qt Creator
**
** Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
**
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**
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** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
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** GNU Lesser General Public License Usage
**
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** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
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#include "sftpchannel.h"
#include "sftpchannel_p.h"

#include "sshexception_p.h"
#include "sshincomingpacket_p.h"
#include "sshsendfacility_p.h"

#include <QtCore/QDir>
#include <QtCore/QFile>

namespace Core {

namespace Internal {
namespace {
    const quint32 ProtocolVersion = 3;

    QString errorMessage(const QString &serverMessage,
        const QString &alternativeMessage)
    {
        return serverMessage.isEmpty() ? alternativeMessage : serverMessage;
    }

    QString errorMessage(const SftpStatusResponse &response,
        const QString &alternativeMessage)
    {
        return response.status == SSH_FX_OK ? QString()
            : errorMessage(response.errorString, alternativeMessage);
    }
} // anonymous namespace
} // namespace Internal

SftpChannel::SftpChannel(quint32 channelId,
    Internal::SshSendFacility &sendFacility)
    : d(new Internal::SftpChannelPrivate(channelId, sendFacility, this))
{
    connect(d, SIGNAL(initialized()), this, SIGNAL(initialized()),
        Qt::QueuedConnection);
    connect(d, SIGNAL(initializationFailed(QString)), this,
        SIGNAL(initializationFailed(QString)), Qt::QueuedConnection);
    connect(d, SIGNAL(dataAvailable(Core::SftpJobId, QString)), this,
        SIGNAL(dataAvailable(Core::SftpJobId, QString)), Qt::QueuedConnection);
    connect(d, SIGNAL(finished(Core::SftpJobId,QString)), this,
        SIGNAL(finished(Core::SftpJobId,QString)), Qt::QueuedConnection);
    connect(d, SIGNAL(closed()), this, SIGNAL(closed()), Qt::QueuedConnection);
}

SftpChannel::State SftpChannel::state() const
{
    switch (d->channelState()) {
    case Internal::AbstractSshChannel::Inactive:
        return Uninitialized;
    case Internal::AbstractSshChannel::SessionRequested:
        return Initializing;
    case Internal::AbstractSshChannel::CloseRequested:
        return Closing;
    case Internal::AbstractSshChannel::Closed:
        return Closed;
    case Internal::AbstractSshChannel::SessionEstablished:
        return d->m_sftpState == Internal::SftpChannelPrivate::Initialized
            ? Initialized : Initializing;
    default:
        Q_ASSERT(!"Oh no, we forgot to handle a channel state!");
        return Closed; // For the compiler.
    }
}

void SftpChannel::initialize()
{
    d->requestSessionStart();
    d->m_sftpState = Internal::SftpChannelPrivate::SubsystemRequested;
}

void SftpChannel::closeChannel()
{
    d->closeChannel();
}

SftpJobId SftpChannel::listDirectory(const QString &path)
{
    return d->createJob(Internal::SftpListDir::Ptr(
        new Internal::SftpListDir(++d->m_nextJobId, path)));
}

SftpJobId SftpChannel::createDirectory(const QString &path)
{
    return d->createJob(Internal::SftpMakeDir::Ptr(
        new Internal::SftpMakeDir(++d->m_nextJobId, path)));
}

SftpJobId SftpChannel::removeDirectory(const QString &path)
{
    return d->createJob(Internal::SftpRmDir::Ptr(
        new Internal::SftpRmDir(++d->m_nextJobId, path)));
}

SftpJobId SftpChannel::removeFile(const QString &path)
{
    return d->createJob(Internal::SftpRm::Ptr(
        new Internal::SftpRm(++d->m_nextJobId, path)));
}

SftpJobId SftpChannel::renameFileOrDirectory(const QString &oldPath,
    const QString &newPath)
{
    return d->createJob(Internal::SftpRename::Ptr(
        new Internal::SftpRename(++d->m_nextJobId, oldPath, newPath)));
}

SftpJobId SftpChannel::createFile(const QString &path, SftpOverwriteMode mode)
{
    return d->createJob(Internal::SftpCreateFile::Ptr(
        new Internal::SftpCreateFile(++d->m_nextJobId, path, mode)));
}

SftpJobId SftpChannel::uploadFile(const QString &localFilePath,
    const QString &remoteFilePath, SftpOverwriteMode mode)
{
    QSharedPointer<QFile> localFile(new QFile(localFilePath));
    if (!localFile->open(QIODevice::ReadOnly))
        return SftpInvalidJob;
    return d->createJob(Internal::SftpUploadFile::Ptr(
        new Internal::SftpUploadFile(++d->m_nextJobId, remoteFilePath, localFile, mode)));
}

SftpJobId SftpChannel::downloadFile(const QString &remoteFilePath,
    const QString &localFilePath, SftpOverwriteMode mode)
{
    QSharedPointer<QFile> localFile(new QFile(localFilePath));
    if (mode == SftpSkipExisting && localFile->exists())
        return SftpInvalidJob;
    QIODevice::OpenMode openMode = QIODevice::WriteOnly;
    if (mode == SftpOverwriteExisting)
        openMode |= QIODevice::Truncate;
    else if (mode == SftpAppendToExisting)
        openMode |= QIODevice::Append;
    if (!localFile->open(openMode))
        return SftpInvalidJob;
    return d->createJob(Internal::SftpDownload::Ptr(
        new Internal::SftpDownload(++d->m_nextJobId, remoteFilePath, localFile)));
}

SftpJobId SftpChannel::uploadDir(const QString &localDirPath,
    const QString &remoteParentDirPath)
{
    if (state() != Initialized)
        return SftpInvalidJob;
    const QDir localDir(localDirPath);
    if (!localDir.exists() || !localDir.isReadable())
        return SftpInvalidJob;
    const Internal::SftpUploadDir::Ptr uploadDirOp(
        new Internal::SftpUploadDir(++d->m_nextJobId));
    const QString remoteDirPath
        = remoteParentDirPath + QLatin1Char('/') + localDir.dirName();
    const Internal::SftpMakeDir::Ptr mkdirOp(
        new Internal::SftpMakeDir(++d->m_nextJobId, remoteDirPath, uploadDirOp));
    uploadDirOp->mkdirsInProgress.insert(mkdirOp,
        Internal::SftpUploadDir::Dir(localDirPath, remoteDirPath));
    d->createJob(mkdirOp);
    return uploadDirOp->jobId;
}

SftpChannel::~SftpChannel()
{
    delete d;
}


namespace Internal {

SftpChannelPrivate::SftpChannelPrivate(quint32 channelId,
    SshSendFacility &sendFacility, SftpChannel *sftp)
    : AbstractSshChannel(channelId, sendFacility),
      m_nextJobId(0), m_sftpState(Inactive), m_sftp(sftp)
{
}

SftpJobId SftpChannelPrivate::createJob(const AbstractSftpOperation::Ptr &job)
{
   if (m_sftp->state() != SftpChannel::Initialized)
       return SftpInvalidJob;
   m_jobs.insert(job->jobId, job);
   sendData(job->initialPacket(m_outgoingPacket).rawData());
   return job->jobId;
}

void SftpChannelPrivate::handleChannelSuccess()
{
#ifdef CREATOR_SSH_DEBUG
    qDebug("sftp subsystem initialized");
#endif
    sendData(m_outgoingPacket.generateInit(ProtocolVersion).rawData());
    m_sftpState = InitSent;
}

void SftpChannelPrivate::handleChannelFailure()
{
    if (m_sftpState != SubsystemRequested) {
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected SSH_MSG_CHANNEL_FAILURE packet.");
    }
    emit initializationFailed(tr("Server could not start sftp subsystem."));
    closeChannel();
}

void SftpChannelPrivate::handleChannelDataInternal(const QByteArray &data)
{
    m_incomingData += data;
    m_incomingPacket.consumeData(m_incomingData);
    while (m_incomingPacket.isComplete()) {
        handleCurrentPacket();
        m_incomingPacket.clear();
        m_incomingPacket.consumeData(m_incomingData);
    }
}

void SftpChannelPrivate::handleChannelExtendedDataInternal(quint32 type,
    const QByteArray &data)
{
    qWarning("Unexpected extended data '%s' of type %d on SFTP channel.",
        data.data(), type);
}

void SftpChannelPrivate::handleExitStatus(const SshChannelExitStatus &exitStatus)
{
    const char * const message = "Remote SFTP service exited with exit code %d";
#ifdef CREATOR_SSH_DEBUG
    qDebug(message, exitStatus.exitStatus);
#else
    if (exitStatus.exitStatus != 0)
        qWarning(message, exitStatus.exitStatus);
#endif
}

void SftpChannelPrivate::handleExitSignal(const SshChannelExitSignal &signal)
{
    qWarning("Remote SFTP service killed; signal was %s", signal.signal.data());
}

void SftpChannelPrivate::handleCurrentPacket()
{
#ifdef CREATOR_SSH_DEBUG
    qDebug("Handling SFTP packet of type %d", m_incomingPacket.type());
#endif
    switch (m_incomingPacket.type()) {
    case SSH_FXP_VERSION:
        handleServerVersion();
        break;
    case SSH_FXP_HANDLE:
        handleHandle();
        break;
    case SSH_FXP_NAME:
        handleName();
        break;
    case SSH_FXP_STATUS:
        handleStatus();
        break;
    case SSH_FXP_DATA:
        handleReadData();
        break;
    case SSH_FXP_ATTRS:
        handleAttrs();
        break;
    default:
        throw SshServerException(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected packet.",
            tr("Unexpected packet of type %1.").arg(m_incomingPacket.type()));
    }
}

void SftpChannelPrivate::handleServerVersion()
{
    checkChannelActive();
    if (m_sftpState != InitSent) {
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected SSH_FXP_VERSION packet.");
    }

#ifdef CREATOR_SSH_DEBUG
    qDebug("sftp init received");
#endif
    const quint32 serverVersion = m_incomingPacket.extractServerVersion();
    if (serverVersion != ProtocolVersion) {
        emit initializationFailed(tr("Protocol version mismatch: Expected %1, got %2")
            .arg(serverVersion).arg(ProtocolVersion));
        closeChannel();
    } else {
        m_sftpState = Initialized;
        emit initialized();
    }
}

void SftpChannelPrivate::handleHandle()
{
    const SftpHandleResponse &response = m_incomingPacket.asHandleResponse();
    JobMap::Iterator it = lookupJob(response.requestId);
    const QSharedPointer<AbstractSftpOperationWithHandle> job
        = it.value().dynamicCast<AbstractSftpOperationWithHandle>();
    if (job.isNull()) {
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected SSH_FXP_HANDLE packet.");
    }
    if (job->state != AbstractSftpOperationWithHandle::OpenRequested) {
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected SSH_FXP_HANDLE packet.");
    }
    job->remoteHandle = response.handle;
    job->state = AbstractSftpOperationWithHandle::Open;

    switch (it.value()->type()) {
    case AbstractSftpOperation::ListDir:
        handleLsHandle(it);
        break;
    case AbstractSftpOperation::CreateFile:
        handleCreateFileHandle(it);
        break;
    case AbstractSftpOperation::Download:
        handleGetHandle(it);
        break;
    case AbstractSftpOperation::UploadFile:
        handlePutHandle(it);
        break;
    default:
        Q_ASSERT(!"Oh no, I forgot to handle an SFTP operation type!");
    }
}

void SftpChannelPrivate::handleLsHandle(const JobMap::Iterator &it)
{
    SftpListDir::Ptr op = it.value().staticCast<SftpListDir>();
    sendData(m_outgoingPacket.generateReadDir(op->remoteHandle,
        op->jobId).rawData());
}

void SftpChannelPrivate::handleCreateFileHandle(const JobMap::Iterator &it)
{
    SftpCreateFile::Ptr op = it.value().staticCast<SftpCreateFile>();
    sendData(m_outgoingPacket.generateCloseHandle(op->remoteHandle,
        op->jobId).rawData());
}

void SftpChannelPrivate::handleGetHandle(const JobMap::Iterator &it)
{
    SftpDownload::Ptr op = it.value().staticCast<SftpDownload>();
    sendData(m_outgoingPacket.generateFstat(op->remoteHandle,
        op->jobId).rawData());
    op->statRequested = true;
}

void SftpChannelPrivate::handlePutHandle(const JobMap::Iterator &it)
{
    SftpUploadFile::Ptr op = it.value().staticCast<SftpUploadFile>();
    if (op->parentJob && op->parentJob->hasError)
        sendTransferCloseHandle(op, it.key());

    // OpenSSH does not implement the RFC's append functionality, so we
    // have to emulate it.
    if (op->mode == SftpAppendToExisting) {
        sendData(m_outgoingPacket.generateFstat(op->remoteHandle,
            op->jobId).rawData());
        op->statRequested = true;
    } else {
        spawnWriteRequests(it);
    }
}

void SftpChannelPrivate::handleStatus()
{
    const SftpStatusResponse &response = m_incomingPacket.asStatusResponse();
#ifdef CREATOR_SSH_DEBUG
    qDebug("%s: status = %d", Q_FUNC_INFO, response.status);
#endif
    JobMap::Iterator it = lookupJob(response.requestId);
    switch (it.value()->type()) {
    case AbstractSftpOperation::ListDir:
        handleLsStatus(it, response);
        break;
    case AbstractSftpOperation::Download:
        handleGetStatus(it, response);
        break;
    case AbstractSftpOperation::UploadFile:
        handlePutStatus(it, response);
        break;
    case AbstractSftpOperation::MakeDir:
        handleMkdirStatus(it, response);
        break;
    case AbstractSftpOperation::RmDir:
    case AbstractSftpOperation::Rm:
    case AbstractSftpOperation::Rename:
    case AbstractSftpOperation::CreateFile:
        handleStatusGeneric(it, response);
        break;
    }
}

void SftpChannelPrivate::handleStatusGeneric(const JobMap::Iterator &it,
    const SftpStatusResponse &response)
{
    AbstractSftpOperation::Ptr op = it.value();
    const QString error = errorMessage(response, tr("Unknown error."));
    emit finished(op->jobId, error);
    m_jobs.erase(it);
}

void SftpChannelPrivate::handleMkdirStatus(const JobMap::Iterator &it,
    const SftpStatusResponse &response)
{
    SftpMakeDir::Ptr op = it.value().staticCast<SftpMakeDir>();
    if (op->parentJob == SftpUploadDir::Ptr()) {
        handleStatusGeneric(it, response);
        return;
    }
    if (op->parentJob->hasError) {
        m_jobs.erase(it);
        return;
    }

    typedef QMap<SftpMakeDir::Ptr, SftpUploadDir::Dir>::Iterator DirIt;
    DirIt dirIt = op->parentJob->mkdirsInProgress.find(op);
    Q_ASSERT(dirIt != op->parentJob->mkdirsInProgress.end());
    const QString &remoteDir = dirIt.value().remoteDir;
    if (response.status == SSH_FX_OK) {
        emit dataAvailable(op->parentJob->jobId,
            tr("Created remote directory '%1'.").arg(remoteDir));
    } else if (response.status == SSH_FX_FAILURE) {
        emit dataAvailable(op->parentJob->jobId,
            tr("Remote directory '%1' already exists.").arg(remoteDir));
    } else {
        op->parentJob->setError();
        emit finished(op->parentJob->jobId,
            tr("Error creating directory '%1': %2")
            .arg(remoteDir, response.errorString));
        m_jobs.erase(it);
        return;
    }

    QDir localDir(dirIt.value().localDir);
    const QFileInfoList &dirInfos
        = localDir.entryInfoList(QDir::Dirs | QDir::NoDotAndDotDot);
    foreach (const QFileInfo &dirInfo, dirInfos) {
        const QString remoteSubDir = remoteDir + '/' + dirInfo.fileName();
        const SftpMakeDir::Ptr mkdirOp(
            new SftpMakeDir(++m_nextJobId, remoteSubDir, op->parentJob));
        op->parentJob->mkdirsInProgress.insert(mkdirOp,
            SftpUploadDir::Dir(dirInfo.absoluteFilePath(), remoteSubDir));
        createJob(mkdirOp);
    }

    const QFileInfoList &fileInfos = localDir.entryInfoList(QDir::Files);
    foreach (const QFileInfo &fileInfo, fileInfos) {
        QSharedPointer<QFile> localFile(new QFile(fileInfo.absoluteFilePath()));
        if (!localFile->open(QIODevice::ReadOnly)) {
            op->parentJob->setError();
            emit finished(op->parentJob->jobId,
                tr("Could not open local file '%1': %2")
                .arg(fileInfo.absoluteFilePath(), localFile->error()));
            m_jobs.erase(it);
            return;
        }

        const QString remoteFilePath = remoteDir + '/' + fileInfo.fileName();
        SftpUploadFile::Ptr uploadFileOp(new SftpUploadFile(++m_nextJobId,
            remoteFilePath, localFile, SftpOverwriteExisting, op->parentJob));
        createJob(uploadFileOp);
        op->parentJob->uploadsInProgress.append(uploadFileOp);
    }

    op->parentJob->mkdirsInProgress.erase(dirIt);
    if (op->parentJob->mkdirsInProgress.isEmpty()
        && op->parentJob->uploadsInProgress.isEmpty())
        emit finished(op->parentJob->jobId);
    m_jobs.erase(it);
}

void SftpChannelPrivate::handleLsStatus(const JobMap::Iterator &it,
    const SftpStatusResponse &response)
{
    SftpListDir::Ptr op = it.value().staticCast<SftpListDir>();
    switch (op->state) {
    case SftpListDir::OpenRequested:
        emit finished(op->jobId, errorMessage(response.errorString,
            tr("Remote directory could not be opened for reading.")));
        m_jobs.erase(it);
        break;
    case SftpListDir::Open:
        if (response.status != SSH_FX_EOF)
            reportRequestError(op, errorMessage(response.errorString,
                tr("Failed to list remote directory contents.")));
        op->state = SftpListDir::CloseRequested;
        sendData(m_outgoingPacket.generateCloseHandle(op->remoteHandle,
            op->jobId).rawData());
        break;
    case SftpListDir::CloseRequested:
        if (!op->hasError) {
            const QString error = errorMessage(response,
                tr("Failed to close remote directory."));
            emit finished(op->jobId, error);
        }
        m_jobs.erase(it);
        break;
    default:
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected SSH_FXP_STATUS packet.");
    }
}

void SftpChannelPrivate::handleGetStatus(const JobMap::Iterator &it,
    const SftpStatusResponse &response)
{
    SftpDownload::Ptr op = it.value().staticCast<SftpDownload>();
    switch (op->state) {
    case SftpDownload::OpenRequested:
        emit finished(op->jobId,
            errorMessage(response.errorString,
                tr("Failed to open remote file for reading.")));
        m_jobs.erase(it);
        break;
    case SftpDownload::Open:
        if (op->statRequested) {
            reportRequestError(op, errorMessage(response.errorString,
                tr("Failed retrieve information on the remote file ('stat' failed).")));
            sendTransferCloseHandle(op, response.requestId);
        } else {
            if ((response.status != SSH_FX_EOF || response.requestId != op->eofId)
                && !op->hasError)
                reportRequestError(op, errorMessage(response.errorString,
                    tr("Failed to read remote file.")));
            finishTransferRequest(it);
        }
        break;
    case SftpDownload::CloseRequested:
        Q_ASSERT(op->inFlightCount == 1);
        if (!op->hasError) {
            if (response.status == SSH_FX_OK)
                emit finished(op->jobId);
            else
                reportRequestError(op, errorMessage(response.errorString,
                    tr("Failed to close remote file.")));
        }
        removeTransferRequest(it);
        break;
    default:
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected SSH_FXP_STATUS packet.");
    }
}

void SftpChannelPrivate::handlePutStatus(const JobMap::Iterator &it,
    const SftpStatusResponse &response)
{
    SftpUploadFile::Ptr job = it.value().staticCast<SftpUploadFile>();
    switch (job->state) {
    case SftpUploadFile::OpenRequested: {
        bool emitError = false;
        if (job->parentJob) {
            if (!job->parentJob->hasError) {
                job->parentJob->setError();
                emitError = true;
            }
        } else {
            emitError = true;
        }

        if (emitError) {
            emit finished(job->jobId,
                errorMessage(response.errorString,
                    tr("Failed to open remote file for writing.")));
        }
        m_jobs.erase(it);
        break;
    }
    case SftpUploadFile::Open:
        if (job->hasError || (job->parentJob && job->parentJob->hasError)) {
            job->hasError = true;
            finishTransferRequest(it);
            return;
        }

        if (response.status == SSH_FX_OK) {
            sendWriteRequest(it);
        } else {
            if (job->parentJob)
                job->parentJob->setError();
            reportRequestError(job, errorMessage(response.errorString,
                tr("Failed to write remote file.")));
            finishTransferRequest(it);
        }
        break;
    case SftpUploadFile::CloseRequested:
        Q_ASSERT(job->inFlightCount == 1);
        if (job->hasError || (job->parentJob && job->parentJob->hasError)) {
            m_jobs.erase(it);
            return;
        }

        if (response.status == SSH_FX_OK) {
            if (job->parentJob) {
                job->parentJob->uploadsInProgress.removeOne(job);
                if (job->parentJob->mkdirsInProgress.isEmpty()
                    && job->parentJob->uploadsInProgress.isEmpty())
                    emit finished(job->parentJob->jobId);
            } else {
                emit finished(job->jobId);
            }
        } else {
            const QString error = errorMessage(response.errorString,
                tr("Failed to close remote file."));
            if (job->parentJob) {
                job->parentJob->setError();
                emit finished(job->parentJob->jobId, error);
            } else {
                emit finished(job->jobId, error);
            }
        }
        m_jobs.erase(it);
        break;
    default:
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected SSH_FXP_STATUS packet.");
    }
}

void SftpChannelPrivate::handleName()
{
    const SftpNameResponse &response = m_incomingPacket.asNameResponse();
    JobMap::Iterator it = lookupJob(response.requestId);
    switch (it.value()->type()) {
    case AbstractSftpOperation::ListDir: {
        SftpListDir::Ptr op = it.value().staticCast<SftpListDir>();
        if (op->state != SftpListDir::Open) {
            throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
                "Unexpected SSH_FXP_NAME packet.");
        }

        for (int i = 0; i < response.files.count(); ++i) {
            const SftpFile &file = response.files.at(i);
            emit dataAvailable(op->jobId, file.fileName);
        }
        sendData(m_outgoingPacket.generateReadDir(op->remoteHandle,
            op->jobId).rawData());
        break;
    }
    default:
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected SSH_FXP_NAME packet.");
    }
}

void SftpChannelPrivate::handleReadData()
{
    const SftpDataResponse &response = m_incomingPacket.asDataResponse();
    JobMap::Iterator it = lookupJob(response.requestId);
    if (it.value()->type() != AbstractSftpOperation::Download) {
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected SSH_FXP_DATA packet.");
    }

    SftpDownload::Ptr op = it.value().staticCast<SftpDownload>();
    if (op->hasError) {
        finishTransferRequest(it);
        return;
    }

    if (!op->localFile->seek(op->offsets[response.requestId])) {
        reportRequestError(op, op->localFile->errorString());
        finishTransferRequest(it);
        return;
    }

    if (op->localFile->write(response.data) != response.data.size()) {
        reportRequestError(op, op->localFile->errorString());
        finishTransferRequest(it);
        return;
    }

    if (op->offset >= op->fileSize && op->fileSize != 0)
        finishTransferRequest(it);
    else
        sendReadRequest(op, response.requestId);
}

void SftpChannelPrivate::handleAttrs()
{
    const SftpAttrsResponse &response = m_incomingPacket.asAttrsResponse();
    JobMap::Iterator it = lookupJob(response.requestId);
    AbstractSftpTransfer::Ptr transfer
        = it.value().dynamicCast<AbstractSftpTransfer>();
    if (!transfer || transfer->state != AbstractSftpTransfer::Open
        || !transfer->statRequested) {
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected SSH_FXP_ATTRS packet.");
    }
    Q_ASSERT(transfer->type() == AbstractSftpOperation::UploadFile
        || transfer->type() == AbstractSftpOperation::Download);

    if (transfer->type() == AbstractSftpOperation::Download) {
        SftpDownload::Ptr op = transfer.staticCast<SftpDownload>();
        if (response.attrs.sizePresent) {
            op->fileSize = response.attrs.size;
        } else {
            op->fileSize = 0;
            op->eofId = op->jobId;
        }
        op->statRequested = false;
        spawnReadRequests(op);
    } else {
        SftpUploadFile::Ptr op = transfer.staticCast<SftpUploadFile>();
        if (op->parentJob && op->parentJob->hasError) {
            op->hasError = true;
            sendTransferCloseHandle(op, op->jobId);
            return;
        }

        if (response.attrs.sizePresent) {
            op->offset = response.attrs.size;
            spawnWriteRequests(it);
        } else {
            if (op->parentJob)
                op->parentJob->setError();
            reportRequestError(op, tr("Cannot append to remote file: "
                "Server does not support the file size attribute."));
            sendTransferCloseHandle(op, op->jobId);
        }
    }
}

SftpChannelPrivate::JobMap::Iterator SftpChannelPrivate::lookupJob(SftpJobId id)
{
    JobMap::Iterator it = m_jobs.find(id);
    if (it == m_jobs.end()) {
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Invalid request id in SFTP packet.");
    }
    return it;
}

void SftpChannelPrivate::closeHook()
{
    emit closed();
}

void SftpChannelPrivate::handleOpenSuccessInternal()
{
#ifdef CREATOR_SSH_DEBUG
    qDebug("SFTP session started");
#endif
    m_sendFacility.sendSftpPacket(remoteChannel());
    m_sftpState = SubsystemRequested;
}

void SftpChannelPrivate::handleOpenFailureInternal()
{
    if (channelState() != SessionRequested) {
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected SSH_MSG_CHANNEL_OPEN_FAILURE packet.");
    }
    emit initializationFailed(tr("Server could not start session."));
}

void SftpChannelPrivate::sendReadRequest(const SftpDownload::Ptr &job,
    quint32 requestId)
{
    Q_ASSERT(job->eofId == SftpInvalidJob);
    sendData(m_outgoingPacket.generateReadFile(job->remoteHandle, job->offset,
        AbstractSftpPacket::MaxDataSize, requestId).rawData());
    job->offsets[requestId] = job->offset;
    job->offset += AbstractSftpPacket::MaxDataSize;
    if (job->offset >= job->fileSize)
        job->eofId = requestId;
}

void SftpChannelPrivate::reportRequestError(const AbstractSftpOperationWithHandle::Ptr &job,
    const QString &error)
{
    emit finished(job->jobId, error);
    job->hasError = true;
}

void SftpChannelPrivate::finishTransferRequest(const JobMap::Iterator &it)
{
    AbstractSftpTransfer::Ptr job = it.value().staticCast<AbstractSftpTransfer>();
    if (job->inFlightCount == 1)
        sendTransferCloseHandle(job, it.key());
    else
        removeTransferRequest(it);
}

void SftpChannelPrivate::sendTransferCloseHandle(const AbstractSftpTransfer::Ptr &job,
    quint32 requestId)
{
    sendData(m_outgoingPacket.generateCloseHandle(job->remoteHandle,
       requestId).rawData());
    job->state = SftpDownload::CloseRequested;
}

void SftpChannelPrivate::removeTransferRequest(const JobMap::Iterator &it)
{
    --it.value().staticCast<AbstractSftpTransfer>()->inFlightCount;
    m_jobs.erase(it);
}

void SftpChannelPrivate::sendWriteRequest(const JobMap::Iterator &it)
{
    SftpUploadFile::Ptr job = it.value().staticCast<SftpUploadFile>();
    QByteArray data = job->localFile->read(AbstractSftpPacket::MaxDataSize);
    if (job->localFile->error() != QFile::NoError) {
        if (job->parentJob)
            job->parentJob->setError();
        reportRequestError(job, tr("Error reading local file: %1")
            .arg(job->localFile->errorString()));
        finishTransferRequest(it);
    } else if (data.isEmpty()) {
        finishTransferRequest(it);
    } else {
        sendData(m_outgoingPacket.generateWriteFile(job->remoteHandle,
            job->offset, data, it.key()).rawData());
        job->offset += AbstractSftpPacket::MaxDataSize;
    }
}

void SftpChannelPrivate::spawnWriteRequests(const JobMap::Iterator &it)
{
    SftpUploadFile::Ptr op = it.value().staticCast<SftpUploadFile>();
    op->calculateInFlightCount(AbstractSftpPacket::MaxDataSize);
    sendWriteRequest(it);
    for (int i = 1; !op->hasError && i < op->inFlightCount; ++i)
        sendWriteRequest(m_jobs.insert(++m_nextJobId, op));
}

void SftpChannelPrivate::spawnReadRequests(const SftpDownload::Ptr &job)
{
    job->calculateInFlightCount(AbstractSftpPacket::MaxDataSize);
    sendReadRequest(job, job->jobId);
    for (int i = 1; i < job->inFlightCount; ++i) {
        const quint32 requestId = ++m_nextJobId;
        m_jobs.insert(requestId, job);
        sendReadRequest(job, requestId);
    }
}

} // namespace Internal
} // namespace Core