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// Copyright (C) 2016 The Qt Company Ltd.
// Copyright (C) 2018 Intel Corporation.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "connection.h"
#include <QTimerEvent>
static const int TransferTimeout = 30 * 1000;
static const int PongTimeout = 60 * 1000;
static const int PingInterval = 5 * 1000;
/*
* Protocol is defined as follows, using the CBOR Data Definition Language:
*
* protocol = [
* greeting, ; must start with a greeting command
* * command ; zero or more regular commands after
* ]
* command = plaintext / ping / pong / greeting
* plaintext = { 0 => text }
* ping = { 1 => null }
* pong = { 2 => null }
* greeting = { 3 => { text, bytes } }
*/
Connection::Connection(QObject *parent)
: QTcpSocket(parent), writer(this)
{
pingTimer.setInterval(PingInterval);
connect(this, &QTcpSocket::readyRead, this,
&Connection::processReadyRead);
connect(this, &QTcpSocket::disconnected,
&pingTimer, &QTimer::stop);
connect(&pingTimer, &QTimer::timeout,
this, &Connection::sendPing);
connect(this, &QTcpSocket::connected,
this, &Connection::sendGreetingMessage);
}
Connection::Connection(qintptr socketDescriptor, QObject *parent)
: Connection(parent)
{
setSocketDescriptor(socketDescriptor);
reader.setDevice(this);
}
Connection::~Connection()
{
if (isGreetingMessageSent && QAbstractSocket::state() != QAbstractSocket::UnconnectedState) {
// Indicate clean shutdown.
writer.endArray();
waitForBytesWritten(2000);
}
}
QString Connection::name() const
{
return username;
}
void Connection::setGreetingMessage(const QString &message, const QByteArray &uniqueId)
{
greetingMessage = message;
localUniqueId = uniqueId;
}
QByteArray Connection::uniqueId() const
{
return peerUniqueId;
}
bool Connection::sendMessage(const QString &message)
{
if (message.isEmpty())
return false;
writer.startMap(1);
writer.append(PlainText);
writer.append(message);
writer.endMap();
return true;
}
void Connection::timerEvent(QTimerEvent *timerEvent)
{
if (timerEvent->timerId() == transferTimerId) {
abort();
killTimer(transferTimerId);
transferTimerId = -1;
}
}
void Connection::processReadyRead()
{
// we've got more data, let's parse
reader.reparse();
while (reader.lastError() == QCborError::NoError) {
if (state == WaitingForGreeting) {
if (!reader.isArray())
break; // protocol error
reader.enterContainer(); // we'll be in this array forever
state = ReadingGreeting;
} else if (reader.containerDepth() == 1) {
// Current state: no command read
// Next state: read command ID
if (!reader.hasNext()) {
reader.leaveContainer();
disconnectFromHost();
return;
}
if (!reader.isMap() || !reader.isLengthKnown() || reader.length() != 1)
break; // protocol error
reader.enterContainer();
} else if (currentDataType == Undefined) {
// Current state: read command ID
// Next state: read command payload
if (!reader.isInteger())
break; // protocol error
currentDataType = DataType(reader.toInteger());
reader.next();
} else {
// Current state: read command payload
if (currentDataType == Greeting) {
if (state == ReadingGreeting) {
if (!reader.isContainer() || !reader.isLengthKnown() || reader.length() != 2)
break; // protocol error
state = ProcessingGreeting;
reader.enterContainer();
}
if (state != ProcessingGreeting)
break; // protocol error
if (reader.isString()) {
auto r = reader.readString();
buffer += r.data;
} else if (reader.isByteArray()) {
auto r = reader.readByteArray();
peerUniqueId += r.data;
if (r.status == QCborStreamReader::EndOfString) {
reader.leaveContainer();
processGreeting();
}
}
if (state == ProcessingGreeting)
continue;
} else if (reader.isString()) {
auto r = reader.readString();
buffer += r.data;
if (r.status != QCborStreamReader::EndOfString)
continue;
} else if (reader.isNull()) {
reader.next();
} else {
break; // protocol error
}
// Next state: no command read
reader.leaveContainer();
if (transferTimerId != -1) {
killTimer(transferTimerId);
transferTimerId = -1;
}
processData();
}
}
if (reader.lastError() != QCborError::EndOfFile)
abort(); // parse error
if (transferTimerId != -1 && reader.containerDepth() > 1)
transferTimerId = startTimer(TransferTimeout);
}
void Connection::sendPing()
{
if (pongTime.elapsed() > PongTimeout) {
abort();
return;
}
writer.startMap(1);
writer.append(Ping);
writer.append(nullptr); // no payload
writer.endMap();
}
void Connection::sendGreetingMessage()
{
writer.startArray(); // this array never ends
writer.startMap(1);
writer.append(Greeting);
writer.startArray(2);
writer.append(greetingMessage);
writer.append(localUniqueId);
writer.endArray();
writer.endMap();
isGreetingMessageSent = true;
if (!reader.device())
reader.setDevice(this);
}
void Connection::processGreeting()
{
username = buffer + '@' + peerAddress().toString() + ':'
+ QString::number(peerPort());
currentDataType = Undefined;
buffer.clear();
if (!isValid()) {
abort();
return;
}
if (!isGreetingMessageSent)
sendGreetingMessage();
pingTimer.start();
pongTime.start();
state = ReadyForUse;
emit readyForUse();
}
void Connection::processData()
{
switch (currentDataType) {
case PlainText:
emit newMessage(username, buffer);
break;
case Ping:
writer.startMap(1);
writer.append(Pong);
writer.append(nullptr); // no payload
writer.endMap();
break;
case Pong:
pongTime.restart();
break;
default:
break;
}
currentDataType = Undefined;
buffer.clear();
}
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