path: root/src/coap/qcoapclient.cpp

/****************************************************************************
**
** Copyright (C) 2017 Witekio.
** Copyright (C) 2018 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtCoap module.
**
** $QT_BEGIN_LICENSE:GPL$
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** the Free Software Foundation and appearing in the file LICENSE.GPL3
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#include "qcoapclient_p.h"
#include "qcoapprotocol_p.h"
#include "qcoapreply.h"
#include "qcoapdiscoveryreply.h"
#include "qcoapnamespace.h"
#include "qcoapsecurityconfiguration.h"
#include "qcoapqudpconnection.h"
#include <QtCore/qiodevice.h>
#include <QtCore/qurl.h>
#include <QtNetwork/qudpsocket.h>

QT_BEGIN_NAMESPACE

QRandomGenerator QtCoap::randomGenerator = QRandomGenerator::securelySeeded();

QCoapClientPrivate::QCoapClientPrivate(QCoapProtocol *protocol, QCoapConnection *connection)
    : protocol(protocol)
    , connection(connection)
    , workerThread(new QThread)
{
    protocol->moveToThread(workerThread);
    connection->moveToThread(workerThread);
    workerThread->start();
}

QCoapClientPrivate::~QCoapClientPrivate()
{
    workerThread->quit();
    workerThread->wait();
    delete workerThread;
    delete protocol;
    delete connection;
}

/*!
  \enum QtCoap::SecurityMode

  Specifies the security mode used for securing a CoAP connection, as defined in
  \l{https://tools.ietf.org/html/rfc7252#section-9}{RFC 7252}.

  \value NoSec              There is no protocol-level security (DTLS is disabled).

  \value PreSharedKey       DTLS is enabled, PSK authentication will be used for security.

  \value RawPublicKey       DTLS is enabled, an asymmetric key pair without a certificate
                            (a raw public key) will be used for security. This mode is not
                            supported yet.

  \value Certificate        DTLS is enabled, an asymmetric key pair with an X.509 certificate
                            will be used for security.
*/
/*!
    \enum QtCoap::Error

    Indicates and error condition found during the processing of the request.

    \value NoError                  No error condition.

    \value HostNotFoundError        The remote host name was not found.

    \value AddressInUseError        The address is already in use.

    \value TimeOutError             The response did not arrive in time.

    \value BadRequestError          The request was not recognized.

    \value Unauthorized             The client is not authorized to perform
                                    the requested action.

    \value BadOption                The request could not be understood by
                                    the server due to one or more unrecognized
                                    or malformed options.

    \value Forbidden                The access to this resource is forbidden.
                                    This Response Code is like HTTP 403
                                    "Forbidden".

    \value NotFound                 The resource requested was not found.
                                    This Response Code is like HTTP 404
                                    "Not Found".

    \value MethodNotAllowed         The method used is not allowed by the server.
                                    This Response Code is like HTTP 405
                                    "Method Not Allowed" but with no parallel
                                    to the "Allow" header field.

    \value NotAcceptable            No resource satisfying the request's acceptance
                                    criteria was found.
                                    This Response Code is like HTTP 406
                                    "Not Acceptable", but with no response entity.

    \value RequestEntityIncomplete  The server has not received the blocks of
                                    the request body that it needs to proceed.
                                    The client has not sent all blocks,
                                    not sent them in the order required by the
                                    server, or has sent them long enough ago
                                    that the server has already discarded them.

    \value PreconditionFailed       One or more conditions given in the request
                                    header fields evaluated to false when tested
                                    on the server.
                                    This Response Code is like HTTP 412
                                    "Precondition Failed".

    \value RequestEntityTooLarge    The request payload is larger than the
                                    server is willing or able to process.
                                    This Response Code is like HTTP 413
                                    "Request Entity Too Large".

    \value UnsupportedContentFormat The payload is in a format not supported
                                    by this method on the target resource.
                                    This Response Code is like HTTP 415
                                    "Unsupported Media Type".

    \value InternalServerError      The server encountered an unexpected
                                    condition that prevented it from
                                    fulfilling the request.
                                    This Response Code is like HTTP 500
                                    "Internal Server Error".

    \value NotImplemented           The server does not support the
                                    functionality required to fulfill the
                                    request.
                                    This Response Code is like HTTP 501
                                    "Not Implemented".

    \value BadGateway               An error occurred with an upstream
                                    server.
                                    This Response Code is like HTTP 502
                                    "Bad Gateway".

    \value ServiceUnavailable       Indicates that the service is currently
                                    Unavailable.
                                    This Response Code is like HTTP 503
                                    "Service Unavailable".

    \value GatewayTimeout           The server, while acting as a gateway
                                    or proxy, did not receive a timely
                                    response from an upstream server it needed
                                    to access in order to complete the request.
                                    This Response Code is like HTTP 504
                                    "Gateway Timeout".

    \value ProxyingNotSupported     The server is unable or unwilling to act
                                    as a forward-proxy for the URI specified
                                    in the Proxy-Uri Option or using
                                    Proxy-Scheme.

    \value UnknownError             An unknown error occurred.

    \sa error()
*/
/*!
    \enum QtCoap::ResponseCode

    This enum represents the response code from the CoAP protocol, as defined in
    \l{https://tools.ietf.org/html/rfc7252#section-5.9}{RFC 7252} and
    \l{https://tools.ietf.org/html/rfc7959#section-2.9}{RFC 7959}.
*/
/*!
    \class QtCoap

    Returns the QtCoap::Error corresponding to the \a code passed to this
    method.
*/
QtCoap::Error QtCoap::responseCodeError(QtCoap::ResponseCode code)
{
    if (!isError(code))
        return QtCoap::NoError;

    switch (code) {
#define SINGLE_CASE(name, ignored) case name: return name ## Error;
        FOR_EACH_COAP_ERROR(SINGLE_CASE)
#undef SINGLE_CASE
    default:
        return UnknownError;
    }
}

/*!
    \class QCoapClient
    \brief The QCoapClient class allows the application to
    send CoAP requests and receive replies.

    \reentrant

    The QCoapClient class contains signals that get triggered when the
    reply of a sent request has arrived.

    The application can use a QCoapClient to send requests over a CoAP
    network. It provides functions for standard requests: each returns a QCoapReply object,
    to which the response data shall be delivered; this can be read when the finished()
    signal arrives.

    A simple request can be sent with:
    \code
        QCoapClient *client = new QCoapClient(this);
        connect(client, &QCoapClient::finished, this, &TestClass::slotFinished);
        client->get(QCoapRequest(Qurl("coap://coap.me/test")));
    \endcode

    \note After the request has finished, it is the responsibility of the user
    to delete the QCoapReply object at an appropriate time. Do not directly
    delete it inside the slot connected to finished(). You can use the
    deleteLater() function.

    You can also use an "observe" request. This can be used as above, or more
    conveniently with the \l{QCoapReply::notified(const QByteArray&)}{notified(const QByteArray&)}
    signal:
    \code
        QCoapRequest request = QCoapRequest(Qurl("coap://coap.me/obs"));
        CoapReply *reply = client->observe(request);
        connect(reply, &QCoapReply::notified, this, &TestClass::slotNotified);
    \endcode

    And the observation can be cancelled with:
    \code
        client->cancelObserve(reply);
    \endcode

    When a reply arrives, the QCoapClient emits a finished(QCoapReply *) signal.

    \note For a discovery request, the returned object is a QCoapDiscoveryReply.
    It can be used the same way as a QCoapReply but contains also a list of
    resources.

    \sa QCoapRequest, QCoapReply, QCoapDiscoveryReply
*/

/*!
    \fn void QCoapClient::finished(QCoapReply *reply)

    This signal is emitted along with the \l{QCoapReply::finished()} signal
    whenever a CoAP reply is finished, after either a success or an error.
    The \a reply parameter will contain a pointer to the reply that has just
    finished.

    \sa error(), QCoapReply::finished(), QCoapReply::error()
*/

/*!
    \fn void QCoapClient::error(QCoapReply *reply, QtCoap::Error error)

    This signal is emitted whenever an error occurs. The \a reply parameter
    can be null if the error is not related to a specific QCoapReply.

    \sa finished(), QCoapReply::error(), QCoapReply::finished()
*/

/*!
    Constructs a QCoapClient object for the given \a securityMode and
    sets \a parent as the parent object.

    The default for \a securityMode is SecurityMode::NoSec, which
    disables security.

    This connects using a QCoapQUdpConnection; to use a custom transport,
    sub-class QCoapConnection and pass an instance to one of the other
    constructors.
*/
QCoapClient::QCoapClient(QtCoap::SecurityMode securityMode, QObject *parent) :
    QCoapClient(new QCoapProtocol, new QCoapQUdpConnection(securityMode), parent)
{
}

/*!
    Constructs a QCoapClient object with the given \a connection and
    sets \a parent as the parent object.
*/
QCoapClient::QCoapClient(QCoapConnection *connection, QObject *parent) :
    QCoapClient(new QCoapProtocol, connection, parent)
{
}

/*!
    Base constructor, taking the \a protocol, \a connection, and \a parent
    as arguments.
*/
QCoapClient::QCoapClient(QCoapProtocol *protocol, QCoapConnection *connection, QObject *parent) :
    QObject(*new QCoapClientPrivate(protocol, connection), parent)
{
    Q_D(QCoapClient);

    qRegisterMetaType<QCoapReply *>();
    qRegisterMetaType<QCoapMessage>();
    qRegisterMetaType<QPointer<QCoapReply>>();
    qRegisterMetaType<QPointer<QCoapDiscoveryReply>>();
    qRegisterMetaType<QCoapConnection *>();
    qRegisterMetaType<QtCoap::Error>();
    qRegisterMetaType<QtCoap::ResponseCode>();
    // Requires a name, as this is a typedef
    qRegisterMetaType<QCoapToken>("QCoapToken");
    qRegisterMetaType<QCoapMessageId>("QCoapMessageId");
    qRegisterMetaType<QAbstractSocket::SocketOption>();

    connect(d->connection, &QCoapConnection::readyRead, d->protocol,
            [this](const QByteArray &data, const QHostAddress &sender) {
                    Q_D(QCoapClient);
                    d->protocol->d_func()->onFrameReceived(data, sender);
            });
    connect(d->connection, &QCoapConnection::error, d->protocol,
            [this](QAbstractSocket::SocketError socketError) {
                    Q_D(QCoapClient);
                    d->protocol->d_func()->onConnectionError(socketError);
            });

    connect(d->protocol, &QCoapProtocol::finished,
            this, &QCoapClient::finished);
    connect(d->protocol, &QCoapProtocol::error,
            this, &QCoapClient::error);
}

/*!
    Destroys the QCoapClient object and frees up any
    resources. Note that QCoapReply objects that are returned from
    this class have the QCoapClient set as their parents, which means that
    they will be deleted along with it.
*/
QCoapClient::~QCoapClient()
{
    qDeleteAll(findChildren<QCoapReply *>(QString(), Qt::FindDirectChildrenOnly));
}

/*!
    Sends the \a request using the GET method and returns a new QCoapReply object.

    \sa post(), put(), deleteResource(), observe(), discover()
*/
QCoapReply *QCoapClient::get(const QCoapRequest &request)
{
    Q_D(QCoapClient);

    if (request.method() != QtCoap::Invalid
            && request.method() != QtCoap::Get) {
        qWarning("QCoapClient::get: Overriding method specified on request:"
                 "using 'Get' instead.");
    }

    QCoapRequest copyRequest(request, QtCoap::Get);
    copyRequest.adjustUrl(d->connection->isSecure());

    return d->sendRequest(copyRequest);
}

/*!
    \overload

    Sends a GET request to \a url and returns a new QCoapReply object.

    \sa post(), put(), deleteResource(), observe(), discover()
*/
QCoapReply *QCoapClient::get(const QUrl &url)
{
    QCoapRequest request(url);
    return get(request);
}

/*!
    Sends the \a request using the PUT method and returns a new QCoapReply
    object. Uses \a data as the payload for this request.

    \sa get(), post(), deleteResource(), observe(), discover()
*/
QCoapReply *QCoapClient::put(const QCoapRequest &request, const QByteArray &data)
{
    Q_D(QCoapClient);

    if (request.method() != QtCoap::Invalid
            && request.method() != QtCoap::Put) {
        qWarning("QCoapClient::put: Overriding method specified on request:"
                 "using 'Put' instead.");
    }

    QCoapRequest copyRequest(request, QtCoap::Put);
    copyRequest.setPayload(data);
    copyRequest.adjustUrl(d->connection->isSecure());

    return d->sendRequest(copyRequest);
}

/*!
    \overload

    Sends the \a request using the PUT method and returns a new QCoapReply
    object. Uses \a device content as the payload for this request.
    A null device is treated as empty content.

    \note The device has to be open and readable before calling this function.

    \sa get(), post(), deleteResource(), observe(), discover()
*/
QCoapReply *QCoapClient::put(const QCoapRequest &request, QIODevice *device)
{
    return put(request, device ? device->readAll() : QByteArray());
}

/*!
    \overload

    Sends a PUT request to \a url and returns a new QCoapReply object.
    Uses \a data as the payload for this request.

    \sa get(), post(), deleteResource(), observe(), discover()
*/
QCoapReply *QCoapClient::put(const QUrl &url, const QByteArray &data)
{
    return put(QCoapRequest(url), data);
}

/*!
    Sends the \a request using the POST method and returns a new QCoapReply
    object. Uses \a data as the payload for this request.

    \sa get(), put(), deleteResource(), observe(), discover()
*/
QCoapReply *QCoapClient::post(const QCoapRequest &request, const QByteArray &data)
{
    Q_D(QCoapClient);

    if (request.method() != QtCoap::Invalid
            && request.method() != QtCoap::Post) {
        qWarning("QCoapClient::post: Overriding method specified on request:"
                 "using 'Post' instead.");
    }

    QCoapRequest copyRequest(request, QtCoap::Post);
    copyRequest.setPayload(data);
    copyRequest.adjustUrl(d->connection->isSecure());

    return d->sendRequest(copyRequest);
}

/*!
    \overload

    Sends the \a request using the POST method and returns a new QCoapReply
    object. Uses \a device content as the payload for this request.
    A null device is treated as empty content.

    \note The device has to be open and readable before calling this function.

    \sa get(), put(), deleteResource(), observe(), discover()
*/
QCoapReply *QCoapClient::post(const QCoapRequest &request, QIODevice *device)
{
    if (!device)
        return nullptr;

    return post(request, device->readAll());
}

/*!
    \overload

    Sends a POST request to \a url and returns a new QCoapReply object.
    Uses \a data as the payload for this request.

    \sa get(), put(), deleteResource(), observe(), discover()
*/
QCoapReply *QCoapClient::post(const QUrl &url, const QByteArray &data)
{
    return post(QCoapRequest(url), data);
}

/*!
    Sends the \a request using the DELETE method and returns a new QCoapReply
    object.

    \sa get(), put(), post(), observe(), discover()
 */
QCoapReply *QCoapClient::deleteResource(const QCoapRequest &request)
{
    Q_D(QCoapClient);

    if (request.method() != QtCoap::Invalid
            && request.method() != QtCoap::Delete) {
        qWarning("QCoapClient::deleteResource: Overriding method specified on request:"
                 "using 'Delete' instead.");
    }

    QCoapRequest copyRequest(request, QtCoap::Delete);
    copyRequest.adjustUrl(d->connection->isSecure());

    return d->sendRequest(copyRequest);
}

/*!
    \overload

    Sends a DELETE request to the target \a url.

    \sa get(), put(), post(), observe(), discover()
 */
QCoapReply *QCoapClient::deleteResource(const QUrl &url)
{
    return deleteResource(QCoapRequest(url));
}

/*!
    Discovers the resources available at the given \a url and returns
    a new QCoapDiscoveryReply object which emits the
    \l{QCoapReply::discovered()}{discovered()} signal whenever the response
    arrives.

    Discovery path defaults to "/.well-known/core", but can be changed
    by passing a different path to \a discoveryPath. Discovery is described in
    \l{https://tools.ietf.org/html/rfc6690#section-1.2.1}{RFC 6690}.

    \sa get(), post(), put(), deleteResource(), observe()
*/
QCoapDiscoveryReply *QCoapClient::discover(const QUrl &url, const QString &discoveryPath)
{
    Q_D(QCoapClient);

    QUrl discoveryUrl(url);
    discoveryUrl.setPath(url.path() + discoveryPath);

    QCoapRequest request(discoveryUrl);
    request.setMethod(QtCoap::Get);
    request.adjustUrl(d->connection->isSecure());

    return d->sendDiscovery(request);
}

/*!
    Sends a request to observe the target \a request and returns
    a new QCoapReply object which emits the
    \l{QCoapReply::notified(const QByteArray&)}{notified(const QByteArray&)}
    signal whenever a new notification arrives.

    \sa cancelObserve(), get(), post(), put(), deleteResource(), discover()
*/
QCoapReply *QCoapClient::observe(const QCoapRequest &request)
{
    if (request.method() != QtCoap::Invalid
            && request.method() != QtCoap::Get) {
        qWarning("QCoapClient::observe: Overriding method specified on request:"
                 "using 'Get' instead.");
    }

    QCoapRequest copyRequest(request, QtCoap::Get);
    copyRequest.enableObserve();

    return get(copyRequest);
}

/*!
    \overload

    Sends a request to observe the target \a url and returns
    a new QCoapReply object which emits the
    \l{QCoapReply::notified(const QByteArray&)}{notified(const QByteArray&)}
    signal whenever a new notification arrives.

    \sa cancelObserve(), get(), post(), put(), deleteResource(), discover()
*/
QCoapReply *QCoapClient::observe(const QUrl &url)
{
    return observe(QCoapRequest(url));
}

/*!
    \overload

    Cancels the observation of a resource using the reply returned by the
    observe() method.

    \sa observe()
*/
void QCoapClient::cancelObserve(QCoapReply *notifiedReply)
{
    // TODO: Plan to add an override to cancel observe with an URL
    Q_D(QCoapClient);
    QMetaObject::invokeMethod(d->protocol, "cancelObserve",
                              Q_ARG(QPointer<QCoapReply>, QPointer<QCoapReply>(notifiedReply)));
}

/*!
    \internal

    Sends the CoAP \a request to its own URL and returns a new QCoapReply
    object.
*/
QCoapReply *QCoapClientPrivate::sendRequest(const QCoapRequest &request)
{
    Q_Q(QCoapClient);

    // Prepare the reply
    QCoapReply *reply = new QCoapReply(request, q);

    if (!send(reply)) {
        delete reply;
        return nullptr;
    }

    return reply;
}

/*!
    \internal

    Sends the CoAP \a request to its own URL and returns a
    new QCoapDiscoveryReply object.
*/
QCoapDiscoveryReply *QCoapClientPrivate::sendDiscovery(const QCoapRequest &request)
{
    Q_Q(QCoapClient);

    // Prepare the reply
    QCoapDiscoveryReply *reply = new QCoapDiscoveryReply(request, q);

    if (!send(reply)) {
        delete reply;
        return nullptr;
    }

    return reply;
}

/*!
    \internal

    Connect to the reply and use the protocol to send it.
*/
bool QCoapClientPrivate::send(QCoapReply *reply)
{
    const auto scheme = connection->isSecure() ? QLatin1String("coaps") : QLatin1String("coap");
    if (reply->request().url().scheme() != scheme) {
        qWarning("QCoapClient: Failed to send request, URL has an incorrect scheme.");
        return false;
    }

    if (!QCoapRequest::isUrlValid(reply->request().url())) {
        qWarning("QCoapClient: Failed to send request for an invalid URL.");
        return false;
    }

    QMetaObject::invokeMethod(protocol, "sendRequest", Qt::QueuedConnection,
                              Q_ARG(QPointer<QCoapReply>, QPointer<QCoapReply>(reply)),
                              Q_ARG(QCoapConnection *, connection));

    return true;
}

/*!
    Sets the security configuration parameters from \a configuration.
    Configuration will be ignored if the QtCoap::NoSec mode is used.

    \note This method must be called before the handshake starts.
*/
void QCoapClient::setSecurityConfiguration(const QCoapSecurityConfiguration &configuration)
{
    Q_D(QCoapClient);

    QMetaObject::invokeMethod(d->connection, "setSecurityConfiguration", Qt::QueuedConnection,
                              Q_ARG(QCoapSecurityConfiguration, configuration));
}

/*!
    Sets the maximum block size used by the protocol when sending requests
    and receiving replies. The block size must be a power of two.

    \sa QCoapProtocol::setBlockSize()
*/
void QCoapClient::setBlockSize(quint16 blockSize)
{
    Q_D(QCoapClient);

    QMetaObject::invokeMethod(d->protocol, "setBlockSize", Qt::QueuedConnection,
                              Q_ARG(quint16, blockSize));
}

/*!
    Sets the QUdpSocket socket \a option to \a value.
*/
void QCoapClient::setSocketOption(QAbstractSocket::SocketOption option, const QVariant &value)
{
    Q_D(QCoapClient);

    QMetaObject::invokeMethod(d->connection, "setSocketOption", Qt::QueuedConnection,
                              Q_ARG(QAbstractSocket::SocketOption, option),
                              Q_ARG(QVariant, value));
}

#if 0
//! Disabled until fully supported
/*!
    Sets the protocol used by the client. Allows use of a custom protocol.
*/
void QCoapClient::setProtocol(QCoapProtocol *protocol)
{
    Q_D(QCoapClient);
    // FIXME: Protocol running on incorrect thread
    d->protocol = protocol;
}
#endif
QT_END_NAMESPACE