network/access/qhttpmultipart.cpp

/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtNetwork module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qhttpmultipart.h"
#include "qhttpmultipart_p.h"
#include "QtCore/qdatetime.h" // for initializing the random number generator with QTime
#include "QtCore/qmutex.h"
#include "QtCore/qrandom.h"

QT_BEGIN_NAMESPACE

/*!
    \class QHttpPart
    \brief The QHttpPart class holds a body part to be used inside a
           HTTP multipart MIME message.
    \since 4.8

    \ingroup network
    \ingroup shared
    \inmodule QtNetwork

    The QHttpPart class holds a body part to be used inside a HTTP
    multipart MIME message (which is represented by the QHttpMultiPart class).
    A QHttpPart consists of a header block
    and a data block, which are separated by each other by two
    consecutive new lines. An example for one part would be:

    \snippet code/src_network_access_qhttppart.cpp 0

    For setting headers, use setHeader() and setRawHeader(), which behave
    exactly like QNetworkRequest::setHeader() and QNetworkRequest::setRawHeader().

    For reading small pieces of data, use setBody(); for larger data blocks
    like e.g. images, use setBodyDevice(). The latter method saves memory by
    not copying the data internally, but reading directly from the device.
    This means that the device must be opened and readable at the moment when
    the multipart message containing the body part is sent on the network via
    QNetworkAccessManager::post().

    To construct a QHttpPart with a small body, consider the following snippet
    (this produces the data shown in the example above):

    \snippet code/src_network_access_qhttppart.cpp 1

    To construct a QHttpPart reading from a device (e.g. a file), the following
    can be applied:

    \snippet code/src_network_access_qhttppart.cpp 2

    Be aware that QHttpPart does not take ownership of the device when set, so
    it is the developer's responsibility to destroy it when it is not needed anymore.
    A good idea might be to set the multipart message as parent object for the device,
    as documented at the documentation for QHttpMultiPart.

    \sa QHttpMultiPart, QNetworkAccessManager
*/


/*!
    Constructs an empty QHttpPart object.
*/
QHttpPart::QHttpPart() : d(new QHttpPartPrivate)
{
}

/*!
    Creates a copy of \a other.
*/
QHttpPart::QHttpPart(const QHttpPart &other) : d(other.d)
{
}

/*!
    Destroys this QHttpPart.
*/
QHttpPart::~QHttpPart()
{
    d = nullptr;
}

/*!
    Creates a copy of \a other.
*/
QHttpPart &QHttpPart::operator=(const QHttpPart &other)
{
    d = other.d;
    return *this;
}

/*!
    \fn void QHttpPart::swap(QHttpPart &other)
    \since 5.0

    Swaps this HTTP part with \a other. This function is very fast and
    never fails.
*/

/*!
    Returns \c true if this object is the same as \a other (i.e., if they
    have the same headers and body).

    \sa operator!=()
*/
bool QHttpPart::operator==(const QHttpPart &other) const
{
    return d == other.d || *d == *other.d;
}

/*!
    \fn bool QHttpPart::operator!=(const QHttpPart &other) const

    Returns \c true if this object is not the same as \a other.

    \sa operator==()
*/

/*!
    Sets the value of the known header \a header to be \a value,
    overriding any previously set headers.

    \sa QNetworkRequest::KnownHeaders, setRawHeader(), QNetworkRequest::setHeader()
*/
void QHttpPart::setHeader(QNetworkRequest::KnownHeaders header, const QVariant &value)
{
    d->setCookedHeader(header, value);
}

/*!
    Sets the header \a headerName to be of value \a headerValue. If \a
    headerName corresponds to a known header (see
    QNetworkRequest::KnownHeaders), the raw format will be parsed and
    the corresponding "cooked" header will be set as well.

    \note Setting the same header twice overrides the previous
    setting. To accomplish the behaviour of multiple HTTP headers of
    the same name, you should concatenate the two values, separating
    them with a comma (",") and set one single raw header.

    \sa QNetworkRequest::KnownHeaders, setHeader(), QNetworkRequest::setRawHeader()
*/
void QHttpPart::setRawHeader(const QByteArray &headerName, const QByteArray &headerValue)
{
    d->setRawHeader(headerName, headerValue);
}

/*!
    Sets the body of this MIME part to \a body. The body set with this method
    will be used unless the device is set via setBodyDevice(). For a large
    amount of data (e.g. an image), use setBodyDevice(), which will not copy
    the data internally.

    \sa setBodyDevice()
*/
void QHttpPart::setBody(const QByteArray &body)
{
    d->setBody(body);
}

/*!
  Sets the device to read the content from to \a device. For large amounts of data
  this method should be preferred over setBody(),
  because the content is not copied when using this method, but read
  directly from the device.
  \a device must be open and readable. QHttpPart does not take ownership
  of \a device, i.e. the device must be closed and destroyed if necessary.
  if \a device is sequential (e.g. sockets, but not files),
  QNetworkAccessManager::post() should be called after \a device has
  emitted finished().
  For unsetting the device and using data set via setBody(), use
  "setBodyDevice(0)".

  \sa setBody(), QNetworkAccessManager::post()
  */
void QHttpPart::setBodyDevice(QIODevice *device)
{
    d->setBodyDevice(device);
}


/*!
    \class QHttpMultiPart
    \brief The QHttpMultiPart class resembles a MIME multipart message to be sent over HTTP.
    \since 4.8

    \ingroup network
    \inmodule QtNetwork

    The QHttpMultiPart resembles a MIME multipart message, as described in RFC 2046,
    which is to be sent over HTTP.
    A multipart message consists of an arbitrary number of body parts (see QHttpPart),
    which are separated by a unique boundary. The boundary of the QHttpMultiPart is
    constructed with the string "boundary_.oOo._" followed by random characters,
    and provides enough uniqueness to make sure it does not occur inside the parts itself.
    If desired, the boundary can still be set via setBoundary().

    As an example, consider the following code snippet, which constructs a multipart
    message containing a text part followed by an image part:

    \snippet code/src_network_access_qhttpmultipart.cpp 0

    \sa QHttpPart, QNetworkAccessManager::post()
*/

/*!
    \enum QHttpMultiPart::ContentType

    List of known content types for a multipart subtype as described
    in RFC 2046 and others.

    \value MixedType    corresponds to the "multipart/mixed" subtype,
    meaning the body parts are independent of each other, as described
    in RFC 2046.

    \value RelatedType  corresponds to the "multipart/related" subtype,
    meaning the body parts are related to each other, as described in RFC 2387.

    \value FormDataType       corresponds to the "multipart/form-data"
    subtype, meaning the body parts contain form elements, as described in RFC 2388.

    \value AlternativeType   corresponds to the "multipart/alternative"
    subtype, meaning the body parts are alternative representations of
    the same information, as described in RFC 2046.

    \sa setContentType()
*/

/*!
    Constructs a QHttpMultiPart with content type MixedType and sets
    \a parent as the parent object.

    \sa QHttpMultiPart::ContentType
*/
QHttpMultiPart::QHttpMultiPart(QObject *parent) : QObject(*new QHttpMultiPartPrivate, parent)
{
    Q_D(QHttpMultiPart);
    d->contentType = MixedType;
}

/*!
    Constructs a QHttpMultiPart with content type \a contentType and
    sets parent as the parent object.

    \sa QHttpMultiPart::ContentType
*/
QHttpMultiPart::QHttpMultiPart(QHttpMultiPart::ContentType contentType, QObject *parent) : QObject(*new QHttpMultiPartPrivate, parent)
{
    Q_D(QHttpMultiPart);
    d->contentType = contentType;
}

/*!
    Destroys the multipart.
*/
QHttpMultiPart::~QHttpMultiPart()
{
}

/*!
    Appends \a httpPart to this multipart.
*/
void QHttpMultiPart::append(const QHttpPart &httpPart)
{
    d_func()->parts.append(httpPart);
}

/*!
    Sets the content type to \a contentType. The content type will be used
    in the HTTP header section when sending the multipart message via
    QNetworkAccessManager::post().
    In case you want to use a multipart subtype not contained in
    QHttpMultiPart::ContentType,
    you can add the "Content-Type" header field to the QNetworkRequest
    by hand, and then use this request together with the multipart
    message for posting.

    \sa QHttpMultiPart::ContentType, QNetworkAccessManager::post()
*/
void QHttpMultiPart::setContentType(QHttpMultiPart::ContentType contentType)
{
    d_func()->contentType = contentType;
}

/*!
    returns the boundary.

    \sa setBoundary()
*/
QByteArray QHttpMultiPart::boundary() const
{
    return d_func()->boundary;
}

/*!
    Sets the boundary to \a boundary.

    Usually, you do not need to generate a boundary yourself; upon construction
    the boundary is initiated with the string "boundary_.oOo._" followed by random
    characters, and provides enough uniqueness to make sure it does not occur
    inside the parts itself.

    \sa boundary()
*/
void QHttpMultiPart::setBoundary(const QByteArray &boundary)
{
    d_func()->boundary = boundary;
}


// ------------------------------------------------------------------
// ----------- implementations of private classes: ------------------
// ------------------------------------------------------------------


qint64 QHttpPartPrivate::bytesAvailable() const
{
    checkHeaderCreated();
    qint64 bytesAvailable = header.count();
    if (bodyDevice) {
        bytesAvailable += bodyDevice->bytesAvailable() - readPointer;
    } else {
        bytesAvailable += body.count() - readPointer;
    }
    // the device might have closed etc., so make sure we do not return a negative value
    return qMax(bytesAvailable, (qint64) 0);
}

qint64 QHttpPartPrivate::readData(char *data, qint64 maxSize)
{
    checkHeaderCreated();
    qint64 bytesRead = 0;
    qint64 headerDataCount = header.count();

    // read header if it has not been read yet
    if (readPointer < headerDataCount) {
        bytesRead = qMin(headerDataCount - readPointer, maxSize);
        const char *headerData = header.constData();
        memcpy(data, headerData + readPointer, bytesRead);
        readPointer += bytesRead;
    }
    // read content if there is still space
    if (bytesRead < maxSize) {
        if (bodyDevice) {
            qint64 dataBytesRead = bodyDevice->read(data + bytesRead, maxSize - bytesRead);
            if (dataBytesRead == -1)
                return -1;
            bytesRead += dataBytesRead;
            readPointer += dataBytesRead;
        } else {
            qint64 contentBytesRead = qMin(body.count() - readPointer + headerDataCount, maxSize - bytesRead);
            const char *contentData = body.constData();
            // if this method is called several times, we need to find the
            // right offset in the content ourselves:
            memcpy(data + bytesRead, contentData + readPointer - headerDataCount, contentBytesRead);
            bytesRead += contentBytesRead;
            readPointer += contentBytesRead;
        }
    }
    return bytesRead;
}

qint64 QHttpPartPrivate::size() const
{
    checkHeaderCreated();
    qint64 size = header.count();
    if (bodyDevice) {
        size += bodyDevice->size();
    } else {
        size += body.count();
    }
    return size;
}

bool QHttpPartPrivate::reset()
{
    bool ret = true;
    if (bodyDevice)
        if (!bodyDevice->reset())
            ret = false;
    readPointer = 0;
    return ret;
}
void QHttpPartPrivate::checkHeaderCreated() const
{
    if (!headerCreated) {
        // copied from QHttpNetworkRequestPrivate::header() and adapted
        QList<QPair<QByteArray, QByteArray> > fields = allRawHeaders();
        QList<QPair<QByteArray, QByteArray> >::const_iterator it = fields.constBegin();
        for (; it != fields.constEnd(); ++it)
            header += it->first + ": " + it->second + "\r\n";
        header += "\r\n";
        headerCreated = true;
    }
}

QHttpMultiPartPrivate::QHttpMultiPartPrivate() : contentType(QHttpMultiPart::MixedType), device(new QHttpMultiPartIODevice(this))
{
    // 24 random bytes, becomes 32 characters when encoded to Base64
    quint32 random[6];
    QRandomGenerator::global()->fillRange(random);
    boundary = "boundary_.oOo._"
               + QByteArray::fromRawData(reinterpret_cast<char *>(random), sizeof(random)).toBase64();

    // boundary must not be longer than 70 characters, see RFC 2046, section 5.1.1
    Q_ASSERT(boundary.count() <= 70);
}

qint64 QHttpMultiPartIODevice::size() const
{
    // if not done yet, we calculate the size and the offsets of each part,
    // including boundary (needed later in readData)
    if (deviceSize == -1) {
        qint64 currentSize = 0;
        qint64 boundaryCount = multiPart->boundary.count();
        for (int a = 0; a < multiPart->parts.count(); a++) {
            partOffsets.append(currentSize);
            // 4 additional bytes for the "--" before and the "\r\n" after the boundary,
            // and 2 bytes for the "\r\n" after the content
            currentSize += boundaryCount + 4 + multiPart->parts.at(a).d->size() + 2;
        }
        currentSize += boundaryCount + 6; // size for ending boundary, 2 beginning and ending dashes and "\r\n"
        deviceSize = currentSize;
    }
    return deviceSize;
}

bool QHttpMultiPartIODevice::isSequential() const
{
    for (int a = 0; a < multiPart->parts.count(); a++) {
        QIODevice *device = multiPart->parts.at(a).d->bodyDevice;
        // we are sequential if any of the bodyDevices of our parts are sequential;
        // when reading from a byte array, we are not sequential
        if (device && device->isSequential())
            return true;
    }
    return false;
}

bool QHttpMultiPartIODevice::reset()
{
    // Reset QIODevice's data
    QIODevice::reset();
    for (int a = 0; a < multiPart->parts.count(); a++)
        if (!multiPart->parts[a].d->reset())
            return false;
    readPointer = 0;
    return true;
}
qint64 QHttpMultiPartIODevice::readData(char *data, qint64 maxSize)
{
    qint64 bytesRead = 0, index = 0;

    // skip the parts we have already read
    while (index < multiPart->parts.count() &&
           readPointer >= partOffsets.at(index) + multiPart->parts.at(index).d->size()
           + multiPart->boundary.count() + 6) // 6 == 2 boundary dashes, \r\n after boundary, \r\n after multipart
        index++;

    // read the data
    while (bytesRead < maxSize && index < multiPart->parts.count()) {

        // check whether we need to read the boundary of the current part
        QByteArray boundaryData = "--" + multiPart->boundary + "\r\n";
        qint64 boundaryCount = boundaryData.count();
        qint64 partIndex = readPointer - partOffsets.at(index);
        if (partIndex < boundaryCount) {
            qint64 boundaryBytesRead = qMin(boundaryCount - partIndex, maxSize - bytesRead);
            memcpy(data + bytesRead, boundaryData.constData() + partIndex, boundaryBytesRead);
            bytesRead += boundaryBytesRead;
            readPointer += boundaryBytesRead;
            partIndex += boundaryBytesRead;
        }

        // check whether we need to read the data of the current part
        if (bytesRead < maxSize && partIndex >= boundaryCount && partIndex < boundaryCount + multiPart->parts.at(index).d->size()) {
            qint64 dataBytesRead = multiPart->parts[index].d->readData(data + bytesRead, maxSize - bytesRead);
            if (dataBytesRead == -1)
                return -1;
            bytesRead += dataBytesRead;
            readPointer += dataBytesRead;
            partIndex += dataBytesRead;
        }

        // check whether we need to read the ending CRLF of the current part
        if (bytesRead < maxSize && partIndex >= boundaryCount + multiPart->parts.at(index).d->size()) {
            if (bytesRead == maxSize - 1)
                return bytesRead;
            memcpy(data + bytesRead, "\r\n", 2);
            bytesRead += 2;
            readPointer += 2;
            index++;
        }
    }
    // check whether we need to return the final boundary
    if (bytesRead < maxSize && index == multiPart->parts.count()) {
        QByteArray finalBoundary = "--" + multiPart->boundary + "--\r\n";
        qint64 boundaryIndex = readPointer + finalBoundary.count() - size();
        qint64 lastBoundaryBytesRead = qMin(finalBoundary.count() - boundaryIndex, maxSize - bytesRead);
        memcpy(data + bytesRead, finalBoundary.constData() + boundaryIndex, lastBoundaryBytesRead);
        bytesRead += lastBoundaryBytesRead;
        readPointer += lastBoundaryBytesRead;
    }
    return bytesRead;
}

qint64 QHttpMultiPartIODevice::writeData(const char *data, qint64 maxSize)
{
    Q_UNUSED(data);
    Q_UNUSED(maxSize);
    return -1;
}


QT_END_NAMESPACE