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/**************************************************************************
**
** This file is part of Qt Creator
**
** Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
**
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** Commercial Usage
**
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
**
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at http://qt.nokia.com/contact.
**
**************************************************************************/
#include "sshchannel_p.h"
#include "sshincomingpacket_p.h"
#include "sshsendfacility_p.h"
#include <botan/exceptn.h>
namespace Core {
namespace Internal {
namespace {
const quint32 MinMaxPacketSize = 32768;
const quint32 MaxPacketSize = 16 * 1024 * 1024;
const quint32 InitialWindowSize = MaxPacketSize;
const quint32 NoChannel = 0xffffffffu;
} // anonymous namespace
AbstractSshChannel::AbstractSshChannel(quint32 channelId,
SshSendFacility &sendFacility)
: m_sendFacility(sendFacility), m_localChannel(channelId),
m_remoteChannel(NoChannel), m_localWindowSize(InitialWindowSize),
m_remoteWindowSize(0), m_state(Inactive)
{
}
AbstractSshChannel::~AbstractSshChannel()
{
}
void AbstractSshChannel::setChannelState(ChannelState state)
{
m_state = state;
if (state == Closed)
closeHook();
}
void AbstractSshChannel::requestSessionStart()
{
// Note: We are just being paranoid here about the Botan exceptions,
// which are extremely unlikely to happen, because if there was a problem
// with our cryptography stuff, it would have hit us before, on
// establishing the connection.
try {
m_sendFacility.sendSessionPacket(m_localChannel, InitialWindowSize,
MaxPacketSize);
setChannelState(SessionRequested);
} catch (Botan::Exception &e) {
m_errorString = QString::fromAscii(e.what());
closeChannel();
}
}
void AbstractSshChannel::sendData(const QByteArray &data)
{
try {
m_sendBuffer += data;
flushSendBuffer();
} catch (Botan::Exception &e) {
m_errorString = QString::fromAscii(e.what());
closeChannel();
}
}
void AbstractSshChannel::handleWindowAdjust(quint32 bytesToAdd)
{
checkChannelActive();
const quint64 newValue = m_remoteWindowSize + bytesToAdd;
if (newValue > 0xffffffffu) {
throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
"Illegal window size requested.");
}
m_remoteWindowSize = newValue;
flushSendBuffer();
}
void AbstractSshChannel::flushSendBuffer()
{
const quint32 bytesToSend
= qMin<quint32>(m_remoteWindowSize, m_sendBuffer.size());
if (bytesToSend > 0) {
const QByteArray &data = m_sendBuffer.left(bytesToSend);
m_sendFacility.sendChannelDataPacket(m_remoteChannel, data);
m_sendBuffer.remove(0, bytesToSend);
m_remoteWindowSize -= bytesToSend;
}
}
void AbstractSshChannel::handleOpenSuccess(quint32 remoteChannelId,
quint32 remoteWindowSize, quint32 remoteMaxPacketSize)
{
if (m_state != SessionRequested) {
throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
"Invalid SSH_MSG_CHANNEL_OPEN_CONFIRMATION packet.");
}
if (remoteMaxPacketSize < MinMaxPacketSize) {
throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
"Maximum packet size too low.");
}
#ifdef CREATOR_SSH_DEBUG
qDebug("Channel opened. remote channel id: %u, remote window size: %u, "
"remote max packet size: %u",
remoteChannelId, remoteWindowSize, remoteMaxPacketSize);
#endif
m_remoteChannel = remoteChannelId;
m_remoteWindowSize = remoteWindowSize;
m_remoteMaxPacketSize = remoteMaxPacketSize;
setChannelState(SessionEstablished);
handleOpenSuccessInternal();
}
void AbstractSshChannel::handleOpenFailure(const QString &reason)
{
if (m_state != SessionRequested) {
throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
"Invalid SSH_MSG_CHANNEL_OPEN_FAILURE packet.");
}
#ifdef CREATOR_SSH_DEBUG
qDebug("Channel open request failed for channel %u", m_localChannel);
#endif
m_errorString = reason;
handleOpenFailureInternal();
}
void AbstractSshChannel::handleChannelEof()
{
if (m_state == Inactive || m_state == Closed) {
throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
"Unexpected SSH_MSG_CHANNEL_EOF message.");
}
m_localWindowSize = 0;
}
void AbstractSshChannel::handleChannelClose()
{
#ifdef CREATOR_SSH_DEBUG
qDebug("Receiving CLOSE for channel %u", m_localChannel);
#endif
if (channelState() == Inactive || channelState() == Closed) {
throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
"Unexpected SSH_MSG_CHANNEL_CLOSE message.");
}
closeChannel();
setChannelState(Closed);
}
void AbstractSshChannel::handleChannelData(const QByteArray &data)
{
const int bytesToDeliver = handleChannelOrExtendedChannelData(data);
handleChannelDataInternal(bytesToDeliver == data.size()
? data : data.left(bytesToDeliver));
}
void AbstractSshChannel::handleChannelExtendedData(quint32 type, const QByteArray &data)
{
const int bytesToDeliver = handleChannelOrExtendedChannelData(data);
handleChannelExtendedDataInternal(type, bytesToDeliver == data.size()
? data : data.left(bytesToDeliver));
}
void AbstractSshChannel::handleChannelRequest(const SshIncomingPacket &packet)
{
qWarning("Ignoring unknown request type '%s'",
packet.extractChannelRequestType().data());
}
int AbstractSshChannel::handleChannelOrExtendedChannelData(const QByteArray &data)
{
checkChannelActive();
const int bytesToDeliver = qMin<quint32>(data.size(), maxDataSize());
if (bytesToDeliver != data.size())
qWarning("Misbehaving server does not respect local window, clipping.");
m_localWindowSize -= bytesToDeliver;
if (m_localWindowSize < MaxPacketSize) {
m_localWindowSize += MaxPacketSize;
m_sendFacility.sendWindowAdjustPacket(m_remoteChannel,
MaxPacketSize);
}
return bytesToDeliver;
}
void AbstractSshChannel::closeChannel()
{
if (m_state != CloseRequested && m_state != Closed) {
if (m_state == Inactive) {
setChannelState(Closed);
} else {
setChannelState(CloseRequested);
m_sendFacility.sendChannelEofPacket(m_remoteChannel);
m_sendFacility.sendChannelClosePacket(m_remoteChannel);
}
}
}
void AbstractSshChannel::checkChannelActive()
{
if (channelState() == Inactive || channelState() == Closed)
throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
"Channel not open.");
}
quint32 AbstractSshChannel::maxDataSize() const
{
return qMin(m_localWindowSize, MaxPacketSize);
}
} // namespace Internal
} // namespace Core
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