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#include "sshremoteprocess.h"
#include "sshremoteprocess_p.h"

#include "sshincomingpacket_p.h"
#include "sshsendfacility_p.h"

#include <botan/exceptn.h>

#include <utils/qtcassert.h>

#include <QtCore/QTimer>

/*!
    \class Utils::SshRemoteProcess

    \brief This class implements an SSH channel for running a remote process.

    Objects are created via SshConnection::createRemoteProcess.
    The process is started via the start() member function.
    A closeChannel() function is provided, but rarely useful, because

    \list
    \i  a) when the process ends, the channel is closed automatically, and
    \i  b) closing a channel will not necessarily kill the remote process.
    \endlist

    Therefore, the only sensible use case for calling closeChannel() is to
    get rid of an SshRemoteProces object before the process is actually started.
    If the process needs a pseudo terminal, you can request one
    via requestTerminal() before calling start().
 */

namespace Utils {

const QByteArray SshRemoteProcess::AbrtSignal("ABRT");
const QByteArray SshRemoteProcess::AlrmSignal("ALRM");
const QByteArray SshRemoteProcess::FpeSignal("FPE");
const QByteArray SshRemoteProcess::HupSignal("HUP");
const QByteArray SshRemoteProcess::IllSignal("ILL");
const QByteArray SshRemoteProcess::IntSignal("INT");
const QByteArray SshRemoteProcess::KillSignal("KILL");
const QByteArray SshRemoteProcess::PipeSignal("PIPE");
const QByteArray SshRemoteProcess::QuitSignal("QUIT");
const QByteArray SshRemoteProcess::SegvSignal("SEGV");
const QByteArray SshRemoteProcess::TermSignal("TERM");
const QByteArray SshRemoteProcess::Usr1Signal("USR1");
const QByteArray SshRemoteProcess::Usr2Signal("USR2");

SshRemoteProcess::SshRemoteProcess(const QByteArray &command, quint32 channelId,
    Internal::SshSendFacility &sendFacility)
    : d(new Internal::SshRemoteProcessPrivate(command, channelId, sendFacility, this))
{
    init();
}

SshRemoteProcess::SshRemoteProcess(quint32 channelId, Internal::SshSendFacility &sendFacility)
    : d(new Internal::SshRemoteProcessPrivate(channelId, sendFacility, this))
{
    init();
}

SshRemoteProcess::~SshRemoteProcess()
{
    Q_ASSERT(d->channelState() == Internal::SshRemoteProcessPrivate::Inactive
        || d->channelState() == Internal::SshRemoteProcessPrivate::CloseRequested
        || d->channelState() == Internal::SshRemoteProcessPrivate::Closed);
    delete d;
}

void SshRemoteProcess::init()
{
    connect(d, SIGNAL(started()), this, SIGNAL(started()),
        Qt::QueuedConnection);
    connect(d, SIGNAL(outputAvailable(QByteArray)), this,
        SIGNAL(outputAvailable(QByteArray)), Qt::QueuedConnection);
    connect(d, SIGNAL(errorOutputAvailable(QByteArray)), this,
        SIGNAL(errorOutputAvailable(QByteArray)), Qt::QueuedConnection);
    connect(d, SIGNAL(closed(int)), this, SIGNAL(closed(int)),
        Qt::QueuedConnection);
}

void SshRemoteProcess::addToEnvironment(const QByteArray &var, const QByteArray &value)
{
    if (d->channelState() == Internal::SshRemoteProcessPrivate::Inactive)
        d->m_env << qMakePair(var, value); // Cached locally and sent on start()
}

void SshRemoteProcess::requestTerminal(const SshPseudoTerminal &terminal)
{
    QTC_ASSERT(d->channelState() == Internal::SshRemoteProcessPrivate::Inactive, return);
    d->m_useTerminal = true;
    d->m_terminal = terminal;
}

void SshRemoteProcess::start()
{
    if (d->channelState() == Internal::SshRemoteProcessPrivate::Inactive) {
#ifdef CREATOR_SSH_DEBUG
        qDebug("process start requested, channel id = %u", d->localChannelId());
#endif
        d->requestSessionStart();
    }
}

void SshRemoteProcess::sendSignal(const QByteArray &signal)
{
    try {
        if (isRunning())
            d->m_sendFacility.sendChannelSignalPacket(d->remoteChannel(),
                signal);
    }  catch (Botan::Exception &e) {
        d->setError(QString::fromAscii(e.what()));
        d->closeChannel();
    }
}

void SshRemoteProcess::closeChannel()
{
    d->closeChannel();
}

void SshRemoteProcess::sendInput(const QByteArray &data)
{
    if (isRunning())
        d->sendData(data);
}

bool SshRemoteProcess::isRunning() const
{
    return d->m_procState == Internal::SshRemoteProcessPrivate::Running;
}

QString SshRemoteProcess::errorString() const { return d->errorString(); }

int SshRemoteProcess::exitCode() const { return d->m_exitCode; }

QByteArray SshRemoteProcess::exitSignal() const { return d->m_signal; }

namespace Internal {

SshRemoteProcessPrivate::SshRemoteProcessPrivate(const QByteArray &command,
        quint32 channelId, SshSendFacility &sendFacility, SshRemoteProcess *proc)
    : AbstractSshChannel(channelId, sendFacility),
      m_command(command),
      m_isShell(false),
      m_useTerminal(false),
      m_proc(proc)
{
    init();
}

SshRemoteProcessPrivate::SshRemoteProcessPrivate(quint32 channelId, SshSendFacility &sendFacility,
            SshRemoteProcess *proc)
    : AbstractSshChannel(channelId, sendFacility),
      m_isShell(true),
      m_useTerminal(true),
      m_proc(proc)
{
    init();
}

void SshRemoteProcessPrivate::init()
{
    m_procState = NotYetStarted;
    m_wasRunning = false;
    m_exitCode = 0;
}

void SshRemoteProcessPrivate::setProcState(ProcessState newState)
{
#ifdef CREATOR_SSH_DEBUG
    qDebug("channel: old state = %d,new state = %d", m_procState, newState);
#endif
    m_procState = newState;
    if (newState == StartFailed) {
        emit closed(SshRemoteProcess::FailedToStart);
    } else if (newState == Running) {
        m_wasRunning = true;
        emit started();
    }
}

void SshRemoteProcessPrivate::closeHook()
{
    if (m_wasRunning) {
        if (!m_signal.isEmpty())
            emit closed(SshRemoteProcess::KilledBySignal);
        else
            emit closed(SshRemoteProcess::ExitedNormally);
    }
}

void SshRemoteProcessPrivate::handleOpenSuccessInternal()
{
   foreach (const EnvVar &envVar, m_env) {
       m_sendFacility.sendEnvPacket(remoteChannel(), envVar.first,
           envVar.second);
   }

   if (m_useTerminal)
       m_sendFacility.sendPtyRequestPacket(remoteChannel(), m_terminal);

   if (m_isShell)
       m_sendFacility.sendShellPacket(remoteChannel());
   else
       m_sendFacility.sendExecPacket(remoteChannel(), m_command);
   setProcState(ExecRequested);
   m_timeoutTimer->start(ReplyTimeout);
}

void SshRemoteProcessPrivate::handleOpenFailureInternal()
{
   setProcState(StartFailed);
}

void SshRemoteProcessPrivate::handleChannelSuccess()
{
    if (m_procState != ExecRequested)  {
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected SSH_MSG_CHANNEL_SUCCESS message.");
    }
    m_timeoutTimer->stop();
    setProcState(Running);
}

void SshRemoteProcessPrivate::handleChannelFailure()
{
    if (m_procState != ExecRequested)  {
        throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_PROTOCOL_ERROR,
            "Unexpected SSH_MSG_CHANNEL_FAILURE message.");
    }
    m_timeoutTimer->stop();
    setProcState(StartFailed);
    closeChannel();
}

void SshRemoteProcessPrivate::handleChannelDataInternal(const QByteArray &data)
{
    emit outputAvailable(data);
}

void SshRemoteProcessPrivate::handleChannelExtendedDataInternal(quint32 type,
    const QByteArray &data)
{
    if (type != SSH_EXTENDED_DATA_STDERR)
        qWarning("Unknown extended data type %u", type);
    else
        emit errorOutputAvailable(data);
}

void SshRemoteProcessPrivate::handleExitStatus(const SshChannelExitStatus &exitStatus)
{
#ifdef CREATOR_SSH_DEBUG
    qDebug("Process exiting with exit code %d", exitStatus.exitStatus);
#endif
    m_exitCode = exitStatus.exitStatus;
    m_procState = Exited;
}

void SshRemoteProcessPrivate::handleExitSignal(const SshChannelExitSignal &signal)
{
#ifdef CREATOR_SSH_DEBUG
    qDebug("Exit due to signal %s", signal.signal.data());
#endif
    setError(signal.error);
    m_signal = signal.signal;
    m_procState = Exited;
}

} // namespace Internal
} // namespace Utils
