summaryrefslogtreecommitdiff
path: root/src/websockets/qwebsocketdataprocessor.cpp
blob: 0b787d2af50c91cb2882887afa1a752e5db6cf91 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
/****************************************************************************
**
** Copyright (C) 2016 Kurt Pattyn <pattyn.kurt@gmail.com>.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtWebSockets 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.
**
** $QT_END_LICENSE$
**
****************************************************************************/
/*!
    \class QWebSocketDataProcessor
    The class QWebSocketDataProcessor is responsible for reading, validating and
    interpreting data from a WebSocket.
    It reads data from a QIODevice, validates it against RFC 6455, and parses it into
    frames (data, control).
    It emits signals that correspond to the type of the frame: textFrameReceived(),
    binaryFrameReceived(), textMessageReceived(), binaryMessageReceived(), pingReceived(),
    pongReceived() and closeReceived().
    Whenever an error is detected, the errorEncountered() signal is emitted.
    QWebSocketDataProcessor also checks if a frame is allowed in a sequence of frames
    (e.g. a continuation frame cannot follow a final frame).
    This class is an internal class used by QWebSocketInternal for data processing and validation.

    \sa Frame()

    \internal
*/
#include "qwebsocketdataprocessor_p.h"
#include "qwebsocketprotocol.h"
#include "qwebsocketprotocol_p.h"
#include "qwebsocketframe_p.h"

#include <QtCore/QtEndian>
#include <QtCore/QTextCodec>
#include <QtCore/QTextDecoder>
#include <QtCore/QDebug>

#include <limits.h>

QT_BEGIN_NAMESPACE

/*!
    \internal
 */
QWebSocketDataProcessor::QWebSocketDataProcessor(QObject *parent) :
    QObject(parent),
    m_processingState(PS_READ_HEADER),
    m_isFinalFrame(false),
    m_isFragmented(false),
    m_opCode(QWebSocketProtocol::OpCodeClose),
    m_isControlFrame(false),
    m_hasMask(false),
    m_mask(0),
    m_binaryMessage(),
    m_textMessage(),
    m_payloadLength(0),
    m_pConverterState(Q_NULLPTR),
    m_pTextCodec(QTextCodec::codecForName("UTF-8"))
{
    clear();
}

/*!
    \internal
 */
QWebSocketDataProcessor::~QWebSocketDataProcessor()
{
    clear();
    if (m_pConverterState) {
        delete m_pConverterState;
        m_pConverterState = Q_NULLPTR;
    }
}

/*!
    \internal
 */
quint64 QWebSocketDataProcessor::maxMessageSize()
{
    return MAX_MESSAGE_SIZE_IN_BYTES;   //COV_NF_LINE
}

/*!
    \internal
 */
quint64 QWebSocketDataProcessor::maxFrameSize()
{
    return MAX_FRAME_SIZE_IN_BYTES;
}

/*!
    \internal
 */
void QWebSocketDataProcessor::process(QIODevice *pIoDevice)
{
    bool isDone = false;

    while (!isDone) {
        QWebSocketFrame frame = QWebSocketFrame::readFrame(pIoDevice);
        if (Q_LIKELY(frame.isValid())) {
            if (frame.isControlFrame()) {
                isDone = processControlFrame(frame);
            } else {
                //we have a dataframe; opcode can be OC_CONTINUE, OC_TEXT or OC_BINARY
                if (Q_UNLIKELY(!m_isFragmented && frame.isContinuationFrame())) {
                    clear();
                    Q_EMIT errorEncountered(QWebSocketProtocol::CloseCodeProtocolError,
                                            tr("Received Continuation frame, while there is " \
                                               "nothing to continue."));
                    return;
                }
                if (Q_UNLIKELY(m_isFragmented && frame.isDataFrame() &&
                               !frame.isContinuationFrame())) {
                    clear();
                    Q_EMIT errorEncountered(QWebSocketProtocol::CloseCodeProtocolError,
                                            tr("All data frames after the initial data frame " \
                                               "must have opcode 0 (continuation)."));
                    return;
                }
                if (!frame.isContinuationFrame()) {
                    m_opCode = frame.opCode();
                    m_isFragmented = !frame.isFinalFrame();
                }
                quint64 messageLength = (quint64)(m_opCode == QWebSocketProtocol::OpCodeText)
                        ? m_textMessage.length()
                        : m_binaryMessage.length();
                if (Q_UNLIKELY((messageLength + quint64(frame.payload().length())) >
                               MAX_MESSAGE_SIZE_IN_BYTES)) {
                    clear();
                    Q_EMIT errorEncountered(QWebSocketProtocol::CloseCodeTooMuchData,
                                            tr("Received message is too big."));
                    return;
                }

                if (m_opCode == QWebSocketProtocol::OpCodeText) {
                    QString frameTxt = m_pTextCodec->toUnicode(frame.payload().constData(),
                                                               frame.payload().size(),
                                                               m_pConverterState);
                    bool failed = (m_pConverterState->invalidChars != 0)
                            || (frame.isFinalFrame() && (m_pConverterState->remainingChars != 0));
                    if (Q_UNLIKELY(failed)) {
                        clear();
                        Q_EMIT errorEncountered(QWebSocketProtocol::CloseCodeWrongDatatype,
                                                tr("Invalid UTF-8 code encountered."));
                        return;
                    } else {
                        m_textMessage.append(frameTxt);
                        Q_EMIT textFrameReceived(frameTxt, frame.isFinalFrame());
                    }
                } else {
                    m_binaryMessage.append(frame.payload());
                    Q_EMIT binaryFrameReceived(frame.payload(), frame.isFinalFrame());
                }

                if (frame.isFinalFrame()) {
                    if (m_opCode == QWebSocketProtocol::OpCodeText)
                        Q_EMIT textMessageReceived(m_textMessage);
                    else
                        Q_EMIT binaryMessageReceived(m_binaryMessage);
                    clear();
                    isDone = true;
                }
            }
        } else {
            Q_EMIT errorEncountered(frame.closeCode(), frame.closeReason());
            clear();
            isDone = true;
        }
    }
}

/*!
    \internal
 */
void QWebSocketDataProcessor::clear()
{
    m_processingState = PS_READ_HEADER;
    m_isFinalFrame = false;
    m_isFragmented = false;
    m_opCode = QWebSocketProtocol::OpCodeClose;
    m_hasMask = false;
    m_mask = 0;
    m_binaryMessage.clear();
    m_textMessage.clear();
    m_payloadLength = 0;
    if (m_pConverterState) {
        if ((m_pConverterState->remainingChars != 0) || (m_pConverterState->invalidChars != 0)) {
            delete m_pConverterState;
            m_pConverterState = Q_NULLPTR;
        }
    }
    if (!m_pConverterState)
        m_pConverterState = new QTextCodec::ConverterState(QTextCodec::ConvertInvalidToNull |
                                                           QTextCodec::IgnoreHeader);
}

/*!
    \internal
 */
bool QWebSocketDataProcessor::processControlFrame(const QWebSocketFrame &frame)
{
    bool mustStopProcessing = true; //control frames never expect additional frames to be processed
    switch (frame.opCode()) {
    case QWebSocketProtocol::OpCodePing:
        Q_EMIT pingReceived(frame.payload());
        break;

    case QWebSocketProtocol::OpCodePong:
        Q_EMIT pongReceived(frame.payload());
        break;

    case QWebSocketProtocol::OpCodeClose:
    {
        quint16 closeCode = QWebSocketProtocol::CloseCodeNormal;
        QString closeReason;
        QByteArray payload = frame.payload();
        if (Q_UNLIKELY(payload.size() == 1)) {
            //size is either 0 (no close code and no reason)
            //or >= 2 (at least a close code of 2 bytes)
            closeCode = QWebSocketProtocol::CloseCodeProtocolError;
            closeReason = tr("Payload of close frame is too small.");
        } else if (Q_LIKELY(payload.size() > 1)) {
            //close frame can have a close code and reason
            closeCode = qFromBigEndian<quint16>(reinterpret_cast<const uchar *>(payload.constData()));
            if (Q_UNLIKELY(!QWebSocketProtocol::isCloseCodeValid(closeCode))) {
                closeCode = QWebSocketProtocol::CloseCodeProtocolError;
                closeReason = tr("Invalid close code %1 detected.").arg(closeCode);
            } else {
                if (payload.size() > 2) {
                    QTextCodec *tc = QTextCodec::codecForName(QByteArrayLiteral("UTF-8"));
                    QTextCodec::ConverterState state(QTextCodec::ConvertInvalidToNull);
                    closeReason = tc->toUnicode(payload.constData() + 2, payload.size() - 2, &state);
                    const bool failed = (state.invalidChars != 0) || (state.remainingChars != 0);
                    if (Q_UNLIKELY(failed)) {
                        closeCode = QWebSocketProtocol::CloseCodeWrongDatatype;
                        closeReason = tr("Invalid UTF-8 code encountered.");
                    }
                }
            }
        }
        Q_EMIT closeReceived(static_cast<QWebSocketProtocol::CloseCode>(closeCode), closeReason);
        break;
    }

    case QWebSocketProtocol::OpCodeContinue:
    case QWebSocketProtocol::OpCodeBinary:
    case QWebSocketProtocol::OpCodeText:
    case QWebSocketProtocol::OpCodeReserved3:
    case QWebSocketProtocol::OpCodeReserved4:
    case QWebSocketProtocol::OpCodeReserved5:
    case QWebSocketProtocol::OpCodeReserved6:
    case QWebSocketProtocol::OpCodeReserved7:
    case QWebSocketProtocol::OpCodeReservedC:
    case QWebSocketProtocol::OpCodeReservedB:
    case QWebSocketProtocol::OpCodeReservedD:
    case QWebSocketProtocol::OpCodeReservedE:
    case QWebSocketProtocol::OpCodeReservedF:
        //do nothing
        //case statements added to make C++ compiler happy
        break;

    default:
        Q_EMIT errorEncountered(QWebSocketProtocol::CloseCodeProtocolError,
                                tr("Invalid opcode detected: %1").arg(int(frame.opCode())));
        //do nothing
        break;
    }
    return mustStopProcessing;
}

QT_END_NAMESPACE