pollymc/api/logic/minecraft/forge/ForgeXzDownload.cpp

/* Copyright 2013-2019 MultiMC Contributors
 *
 * 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 "Env.h"
#include "ForgeXzDownload.h"
#include <FileSystem.h>

#include <QCryptographicHash>
#include <QFileInfo>
#include <QDateTime>
#include <QDir>
#include <QDebug>

ForgeXzDownload::ForgeXzDownload(QString url, QString relative_path, MetaEntryPtr entry) : NetAction()
{
    m_entry = entry;
    m_target_path = entry->getFullPath();
    m_pack200_xz_file.setFileTemplate("./dl_temp.XXXXXX");
    m_status = Job_NotStarted;
    m_url_path = relative_path;
    m_url = url + ".pack.xz";
}

void ForgeXzDownload::start()
{
    if(m_status == Job_Aborted)
    {
        qWarning() << "Attempt to start an aborted Download:" << m_url.toString();
        emit aborted(m_index_within_job);
        return;
    }
    m_status = Job_InProgress;
    if (!m_entry->isStale())
    {
        m_status = Job_Finished;
        emit succeeded(m_index_within_job);
        return;
    }
    // can we actually create the real, final file?
    if (!FS::ensureFilePathExists(m_target_path))
    {
        m_status = Job_Failed;
        emit failed(m_index_within_job);
        return;
    }

    qDebug() << "Downloading " << m_url.toString();
    QNetworkRequest request(m_url);
    request.setRawHeader(QString("If-None-Match").toLatin1(), m_entry->getETag().toLatin1());
    request.setHeader(QNetworkRequest::UserAgentHeader, "MultiMC/5.0 (Cached)");

    QNetworkReply *rep = ENV.qnam().get(request);

    m_reply.reset(rep);
    connect(rep, SIGNAL(downloadProgress(qint64, qint64)), SLOT(downloadProgress(qint64, qint64)));
    connect(rep, SIGNAL(finished()), SLOT(downloadFinished()));
    connect(rep, SIGNAL(error(QNetworkReply::NetworkError)), SLOT(downloadError(QNetworkReply::NetworkError)));
    connect(rep, SIGNAL(readyRead()), SLOT(downloadReadyRead()));
}

void ForgeXzDownload::downloadProgress(qint64 bytesReceived, qint64 bytesTotal)
{
    m_total_progress = bytesTotal;
    m_progress = bytesReceived;
    emit netActionProgress(m_index_within_job, bytesReceived, bytesTotal);
}

void ForgeXzDownload::downloadError(QNetworkReply::NetworkError error)
{
    if(error == QNetworkReply::OperationCanceledError)
    {
        qCritical() << "Aborted " << m_url.toString();
        m_status = Job_Aborted;
    }
    else
    {
        // error happened during download.
        qCritical() << "Failed " << m_url.toString() << " with reason " << error;
        m_status = Job_Failed;
    }
}

void ForgeXzDownload::failAndTryNextMirror()
{
    m_status = Job_Failed;
    emit failed(m_index_within_job);
}

void ForgeXzDownload::downloadFinished()
{
    // if the download succeeded
    if (m_status != Job_Failed && m_status != Job_Aborted)
    {
        // nothing went wrong...
        m_status = Job_Finished;
        if (m_pack200_xz_file.isOpen())
        {
            // we actually downloaded something! process and isntall it
            decompressAndInstall();
            return;
        }
        else
        {
            // something bad happened -- on the local machine!
            m_status = Job_Failed;
            m_pack200_xz_file.remove();
            m_reply.reset();
            emit failed(m_index_within_job);
            return;
        }
    }
    else if(m_status == Job_Aborted)
    {
        m_pack200_xz_file.remove();
        m_reply.reset();
        emit failed(m_index_within_job);
        emit aborted(m_index_within_job);
        return;
    }
    // else the download failed
    else
    {
        m_status = Job_Failed;
        m_pack200_xz_file.close();
        m_pack200_xz_file.remove();
        m_reply.reset();
        failAndTryNextMirror();
        return;
    }
}

void ForgeXzDownload::downloadReadyRead()
{

    if (!m_pack200_xz_file.isOpen())
    {
        if (!m_pack200_xz_file.open())
        {
            /*
            * Can't open the file... the job failed
            */
            m_reply->abort();
            emit failed(m_index_within_job);
            return;
        }
    }
    m_pack200_xz_file.write(m_reply->readAll());
}

#include "xz.h"
#include "unpack200.h"
#include <stdexcept>
#include <unistd.h>

const size_t buffer_size = 8196;

// NOTE: once this gets here, it can't be aborted anymore. we don't care.
void ForgeXzDownload::decompressAndInstall()
{
    // rewind the downloaded temp file
    m_pack200_xz_file.seek(0);
    // de-xz'd file
    QTemporaryFile pack200_file("./dl_temp.XXXXXX");
    pack200_file.open();

    bool xz_success = false;
    // first, de-xz
    {
        uint8_t in[buffer_size];
        uint8_t out[buffer_size];
        struct xz_buf b;
        struct xz_dec *s;
        enum xz_ret ret;
        xz_crc32_init();
        xz_crc64_init();
        s = xz_dec_init(XZ_DYNALLOC, 1 << 26);
        if (s == nullptr)
        {
            xz_dec_end(s);
            failAndTryNextMirror();
            return;
        }
        b.in = in;
        b.in_pos = 0;
        b.in_size = 0;
        b.out = out;
        b.out_pos = 0;
        b.out_size = buffer_size;
        while (!xz_success)
        {
            if (b.in_pos == b.in_size)
            {
                b.in_size = m_pack200_xz_file.read((char *)in, sizeof(in));
                b.in_pos = 0;
            }

            ret = xz_dec_run(s, &b);

            if (b.out_pos == sizeof(out))
            {
                auto wresult = pack200_file.write((char *)out, b.out_pos);
                if (wresult < 0 || size_t(wresult) != b.out_pos)
                {
                    // msg = "Write error\n";
                    xz_dec_end(s);
                    failAndTryNextMirror();
                    return;
                }

                b.out_pos = 0;
            }

            if (ret == XZ_OK)
                continue;

            if (ret == XZ_UNSUPPORTED_CHECK)
            {
                // unsupported check. this is OK, but we should log this
                continue;
            }

            auto wresult = pack200_file.write((char *)out, b.out_pos);
            if (wresult < 0 || size_t(wresult) != b.out_pos)
            {
                // write error
                pack200_file.close();
                xz_dec_end(s);
                return;
            }

            switch (ret)
            {
            case XZ_STREAM_END:
                xz_dec_end(s);
                xz_success = true;
                break;

            case XZ_MEM_ERROR:
                qCritical() << "Memory allocation failed\n";
                xz_dec_end(s);
                failAndTryNextMirror();
                return;

            case XZ_MEMLIMIT_ERROR:
                qCritical() << "Memory usage limit reached\n";
                xz_dec_end(s);
                failAndTryNextMirror();
                return;

            case XZ_FORMAT_ERROR:
                qCritical() << "Not a .xz file\n";
                xz_dec_end(s);
                failAndTryNextMirror();
                return;

            case XZ_OPTIONS_ERROR:
                qCritical() << "Unsupported options in the .xz headers\n";
                xz_dec_end(s);
                failAndTryNextMirror();
                return;

            case XZ_DATA_ERROR:
            case XZ_BUF_ERROR:
                qCritical() << "File is corrupt\n";
                xz_dec_end(s);
                failAndTryNextMirror();
                return;

            default:
                qCritical() << "Bug!\n";
                xz_dec_end(s);
                failAndTryNextMirror();
                return;
            }
        }
    }
    m_pack200_xz_file.remove();

    // revert pack200
    pack200_file.seek(0);
    int handle_in = pack200_file.handle();
    // FIXME: dispose of file handles, pointers and the like. Ideally wrap in objects.
    if(handle_in == -1)
    {
        qCritical() << "Error reopening " << pack200_file.fileName();
        failAndTryNextMirror();
        return;
    }
    int handle_in_dup = dup (handle_in);
    if(handle_in_dup == -1)
    {
        qCritical() << "Error reopening " << pack200_file.fileName();
        failAndTryNextMirror();
        return;
    }
    FILE *file_in = fdopen (handle_in_dup, "rb");
    if(!file_in)
    {
        qCritical() << "Error reopening " << pack200_file.fileName();
        failAndTryNextMirror();
        return;
    }
    QFile qfile_out(m_target_path);
    if(!qfile_out.open(QIODevice::WriteOnly))
    {
        qCritical() << "Error opening " << qfile_out.fileName();
        failAndTryNextMirror();
        return;
    }
    int handle_out = qfile_out.handle();
    if(handle_out == -1)
    {
        qCritical() << "Error opening " << qfile_out.fileName();
        failAndTryNextMirror();
        return;
    }
    int handle_out_dup = dup (handle_out);
    if(handle_out_dup == -1)
    {
        qCritical() << "Error reopening " << qfile_out.fileName();
        failAndTryNextMirror();
        return;
    }
    FILE *file_out = fdopen (handle_out_dup, "wb");
    if(!file_out)
    {
        qCritical() << "Error opening " << qfile_out.fileName();
        failAndTryNextMirror();
        return;
    }
    try
    {
        // NOTE: this takes ownership of both FILE pointers. That's why we duplicate them above.
        unpack_200(file_in, file_out);
    }
    catch (const std::runtime_error &err)
    {
        m_status = Job_Failed;
        qCritical() << "Error unpacking " << pack200_file.fileName() << " : " << err.what();
        QFile f(m_target_path);
        if (f.exists())
            f.remove();
        failAndTryNextMirror();
        return;
    }
    pack200_file.remove();

    QFile jar_file(m_target_path);

    if (!jar_file.open(QIODevice::ReadOnly))
    {
        jar_file.remove();
        failAndTryNextMirror();
        return;
    }
    auto hash = QCryptographicHash::hash(jar_file.readAll(), QCryptographicHash::Md5);
    m_entry->setMD5Sum(hash.toHex().constData());
    jar_file.close();

    QFileInfo output_file_info(m_target_path);
    m_entry->setETag(m_reply->rawHeader("ETag").constData());
    m_entry->setLocalChangedTimestamp(output_file_info.lastModified().toUTC().toMSecsSinceEpoch());
    m_entry->setStale(false);
    ENV.metacache()->updateEntry(m_entry);

    m_reply.reset();
    emit succeeded(m_index_within_job);
}

bool ForgeXzDownload::abort()
{
    if(m_reply)
        m_reply->abort();
    m_status = Job_Aborted;
    return true;
}

bool ForgeXzDownload::canAbort()
{
    return true;
}