deskflow/src/lib/client/ServerProxy.cpp

/*
 * Deskflow -- mouse and keyboard sharing utility
 * SPDX-FileCopyrightText: (C) 2012 - 2016 Symless Ltd.
 * SPDX-FileCopyrightText: (C) 2002 Chris Schoeneman
 * SPDX-License-Identifier: GPL-2.0-only WITH LicenseRef-OpenSSL-Exception
 */

#include "client/ServerProxy.h"

#include "base/IEventQueue.h"
#include "base/Log.h"
#include "base/TMethodEventJob.h"
#include "base/XBase.h"
#include "client/Client.h"
#include "deskflow/AppUtil.h"
#include "deskflow/Clipboard.h"
#include "deskflow/ClipboardChunk.h"
#include "deskflow/OptionTypes.h"
#include "deskflow/ProtocolTypes.h"
#include "deskflow/ProtocolUtil.h"
#include "deskflow/StreamChunker.h"
#include "deskflow/XDeskflow.h"
#include "io/IStream.h"

#include <algorithm>
#include <cstring>
#include <memory>

//
// ServerProxy
//

ServerProxy::ServerProxy(Client *client, deskflow::IStream *stream, IEventQueue *events)
    : m_client(client),
      m_stream(stream),
      m_parser(&ServerProxy::parseHandshakeMessage),
      m_events(events)
{
  assert(m_client != nullptr);
  assert(m_stream != nullptr);

  // initialize modifier translation table
  for (KeyModifierID id = 0; id < kKeyModifierIDLast; ++id)
    m_modifierTranslationTable[id] = id;

  // handle data on stream
  m_events->adoptHandler(
      EventTypes::StreamInputReady, m_stream->getEventTarget(),
      new TMethodEventJob<ServerProxy>(this, &ServerProxy::handleData)
  );

  m_events->adoptHandler(
      EventTypes::ClipboardSending, this,
      new TMethodEventJob<ServerProxy>(this, &ServerProxy::handleClipboardSendingEvent)
  );

  // send heartbeat
  setKeepAliveRate(kKeepAliveRate);
}

ServerProxy::~ServerProxy()
{
  setKeepAliveRate(-1.0);
  m_events->removeHandler(EventTypes::StreamInputReady, m_stream->getEventTarget());
}

void ServerProxy::resetKeepAliveAlarm()
{
  if (m_keepAliveAlarmTimer != nullptr) {
    m_events->removeHandler(EventTypes::Timer, m_keepAliveAlarmTimer);
    m_events->deleteTimer(m_keepAliveAlarmTimer);
    m_keepAliveAlarmTimer = nullptr;
  }
  if (m_keepAliveAlarm > 0.0) {
    m_keepAliveAlarmTimer = m_events->newOneShotTimer(m_keepAliveAlarm, nullptr);
    m_events->adoptHandler(
        EventTypes::Timer, m_keepAliveAlarmTimer,
        new TMethodEventJob<ServerProxy>(this, &ServerProxy::handleKeepAliveAlarm)
    );
  }
}

void ServerProxy::setKeepAliveRate(double rate)
{
  m_keepAliveAlarm = rate * kKeepAlivesUntilDeath;
  resetKeepAliveAlarm();
}

void ServerProxy::handleData(const Event &, void *)
{
  // handle messages until there are no more.  first read message code.
  uint8_t code[4];
  uint32_t n = m_stream->read(code, 4);
  while (n != 0) {
    // verify we got an entire code
    if (n != 4) {
      LOG((CLOG_ERR "incomplete message from server: %d bytes", n));
      m_client->disconnect("incomplete message from server");
      return;
    }

    // parse message
    LOG((CLOG_DEBUG2 "msg from server: %c%c%c%c", code[0], code[1], code[2], code[3]));
    try {
      switch ((this->*m_parser)(code)) {
      case kOkay:
        break;

      case kUnknown:
        LOG((CLOG_ERR "invalid message from server: %c%c%c%c", code[0], code[1], code[2], code[3]));
        // not possible to determine message boundaries
        // read the whole stream to discard unkonwn data
        while (m_stream->read(nullptr, 4))
          ;
        break;

      case kDisconnect:
        return;
      }
    } catch (const XBadClient &e) {
      LOG((CLOG_ERR "protocol error from server: %s", e.what()));
      ProtocolUtil::writef(m_stream, kMsgEBad);
      m_client->disconnect("invalid message from server");
      return;
    }

    // next message
    n = m_stream->read(code, 4);
  }

  flushCompressedMouse();
}

ServerProxy::EResult ServerProxy::parseHandshakeMessage(const uint8_t *code)
{
  if (memcmp(code, kMsgQInfo, 4) == 0) {
    queryInfo();
  }

  else if (memcmp(code, kMsgCInfoAck, 4) == 0) {
    infoAcknowledgment();
  }

  else if (memcmp(code, kMsgDSetOptions, 4) == 0) {
    setOptions();

    // handshake is complete
    m_parser = &ServerProxy::parseMessage;
    checkMissedLanguages();
    m_client->handshakeComplete();
  }

  else if (memcmp(code, kMsgCResetOptions, 4) == 0) {
    resetOptions();
  }

  else if (memcmp(code, kMsgCKeepAlive, 4) == 0) {
    // echo keep alives and reset alarm
    ProtocolUtil::writef(m_stream, kMsgCKeepAlive);
    resetKeepAliveAlarm();
  }

  else if (memcmp(code, kMsgCNoop, 4) == 0) {
    // accept and discard no-op
  }

  else if (memcmp(code, kMsgCClose, 4) == 0) {
    // server wants us to hangup
    LOG((CLOG_DEBUG1 "recv close"));
    m_client->disconnect(nullptr);
    return kDisconnect;
  }

  else if (memcmp(code, kMsgEIncompatible, 4) == 0) {
    int32_t major;
    int32_t minor;
    ProtocolUtil::readf(m_stream, kMsgEIncompatible + 4, &major, &minor);
    LOG((CLOG_ERR "server has incompatible version %d.%d", major, minor));
    m_client->refuseConnection("server has incompatible version");
    return kDisconnect;
  }

  else if (memcmp(code, kMsgEBusy, 4) == 0) {
    LOG((CLOG_ERR "server already has a connected client with name \"%s\"", m_client->getName().c_str()));
    m_client->refuseConnection("server already has a connected client with our name");
    return kDisconnect;
  }

  else if (memcmp(code, kMsgEUnknown, 4) == 0) {
    LOG((CLOG_ERR "server refused client with name \"%s\"", m_client->getName().c_str()));
    m_client->refuseConnection("server refused client with our name");
    return kDisconnect;
  }

  else if (memcmp(code, kMsgEBad, 4) == 0) {
    LOG((CLOG_ERR "server disconnected due to a protocol error"));
    m_client->refuseConnection("server reported a protocol error");
    return kDisconnect;
  } else if (memcmp(code, kMsgDLanguageSynchronisation, 4) == 0) {
    setServerLanguages();
  } else {
    return kUnknown;
  }

  return kOkay;
}

ServerProxy::EResult ServerProxy::parseMessage(const uint8_t *code)
{
  if (memcmp(code, kMsgDMouseMove, 4) == 0) {
    mouseMove();
  }

  else if (memcmp(code, kMsgDMouseRelMove, 4) == 0) {
    mouseRelativeMove();
  }

  else if (memcmp(code, kMsgDMouseWheel, 4) == 0) {
    mouseWheel();
  }

  else if (memcmp(code, kMsgDKeyDown, 4) == 0) {
    uint16_t id = 0;
    uint16_t mask = 0;
    uint16_t button = 0;
    ProtocolUtil::readf(m_stream, kMsgDKeyDown + 4, &id, &mask, &button);
    LOG((CLOG_DEBUG1 "recv key down id=0x%08x, mask=0x%04x, button=0x%04x", id, mask, button));

    keyDown(id, mask, button, "");
  }

  else if (memcmp(code, kMsgDKeyDownLang, 4) == 0) {
    std::string lang;
    uint16_t id = 0;
    uint16_t mask = 0;
    uint16_t button = 0;

    ProtocolUtil::readf(m_stream, kMsgDKeyDownLang + 4, &id, &mask, &button, &lang);
    LOG((CLOG_DEBUG1 "recv key down id=0x%08x, mask=0x%04x, button=0x%04x, lang=\"%s\"", id, mask, button, lang.c_str())
    );

    keyDown(id, mask, button, lang);
  }

  else if (memcmp(code, kMsgDKeyUp, 4) == 0) {
    keyUp();
  }

  else if (memcmp(code, kMsgDMouseDown, 4) == 0) {
    mouseDown();
  }

  else if (memcmp(code, kMsgDMouseUp, 4) == 0) {
    mouseUp();
  }

  else if (memcmp(code, kMsgDKeyRepeat, 4) == 0) {
    keyRepeat();
  }

  else if (memcmp(code, kMsgCKeepAlive, 4) == 0) {
    // echo keep alives and reset alarm
    ProtocolUtil::writef(m_stream, kMsgCKeepAlive);
    resetKeepAliveAlarm();
  }

  else if (memcmp(code, kMsgCNoop, 4) == 0) {
    // accept and discard no-op
  }

  else if (memcmp(code, kMsgCEnter, 4) == 0) {
    enter();
  }

  else if (memcmp(code, kMsgCLeave, 4) == 0) {
    leave();
  }

  else if (memcmp(code, kMsgCClipboard, 4) == 0) {
    grabClipboard();
  }

  else if (memcmp(code, kMsgCScreenSaver, 4) == 0) {
    screensaver();
  }

  else if (memcmp(code, kMsgQInfo, 4) == 0) {
    queryInfo();
  }

  else if (memcmp(code, kMsgCInfoAck, 4) == 0) {
    infoAcknowledgment();
  }

  else if (memcmp(code, kMsgDClipboard, 4) == 0) {
    setClipboard();
  }

  else if (memcmp(code, kMsgCResetOptions, 4) == 0) {
    resetOptions();
  }

  else if (memcmp(code, kMsgDSetOptions, 4) == 0) {
    setOptions();
  }

  else if (memcmp(code, kMsgDSecureInputNotification, 4) == 0) {
    secureInputNotification();
  }

  else if (memcmp(code, kMsgCClose, 4) == 0) {
    // server wants us to hangup
    LOG((CLOG_DEBUG1 "recv close"));
    m_client->disconnect(nullptr);
    return kDisconnect;
  } else if (memcmp(code, kMsgEBad, 4) == 0) {
    LOG((CLOG_ERR "server disconnected due to a protocol error"));
    m_client->disconnect("server reported a protocol error");
    return kDisconnect;
  } else {
    return kUnknown;
  }

  // send a reply.  this is intended to work around a delay when
  // running a linux server and an OS X (any BSD?) client.  the
  // client waits to send an ACK (if the system control flag
  // net.inet.tcp.delayed_ack is 1) in hopes of piggybacking it
  // on a data packet.  we provide that packet here.  i don't
  // know why a delayed ACK should cause the server to wait since
  // TCP_NODELAY is enabled.
  ProtocolUtil::writef(m_stream, kMsgCNoop);

  return kOkay;
}

void ServerProxy::handleKeepAliveAlarm(const Event &, void *)
{
  LOG((CLOG_NOTE "server is dead"));
  m_client->disconnect("server is not responding");
}

void ServerProxy::onInfoChanged()
{
  // ignore mouse motion until we receive acknowledgment of our info
  // change message.
  m_ignoreMouse = true;

  // send info update
  queryInfo();
}

bool ServerProxy::onGrabClipboard(ClipboardID id)
{
  LOG((CLOG_DEBUG1 "sending clipboard %d changed", id));
  ProtocolUtil::writef(m_stream, kMsgCClipboard, id, m_seqNum);
  return true;
}

void ServerProxy::onClipboardChanged(ClipboardID id, const IClipboard *clipboard)
{
  std::string data = IClipboard::marshall(clipboard);
  LOG((CLOG_DEBUG "sending clipboard %d seqnum=%d", id, m_seqNum));

  StreamChunker::sendClipboard(data, data.size(), id, m_seqNum, m_events, this);
}

void ServerProxy::flushCompressedMouse()
{
  if (m_compressMouse) {
    m_compressMouse = false;
    m_client->mouseMove(m_xMouse, m_yMouse);
  }
  if (m_compressMouseRelative) {
    m_compressMouseRelative = false;
    m_client->mouseRelativeMove(m_dxMouse, m_dyMouse);
    m_dxMouse = 0;
    m_dyMouse = 0;
  }
}

void ServerProxy::sendInfo(const ClientInfo &info)
{
  LOG((CLOG_DEBUG1 "sending info shape=%d,%d %dx%d", info.m_x, info.m_y, info.m_w, info.m_h));
  ProtocolUtil::writef(m_stream, kMsgDInfo, info.m_x, info.m_y, info.m_w, info.m_h, 0, info.m_mx, info.m_my);
}

KeyID ServerProxy::translateKey(KeyID id) const
{
  static const KeyID s_translationTable[kKeyModifierIDLast][2] = {
      {kKeyNone, kKeyNone},     {kKeyShift_L, kKeyShift_R}, {kKeyControl_L, kKeyControl_R}, {kKeyAlt_L, kKeyAlt_R},
      {kKeyMeta_L, kKeyMeta_R}, {kKeySuper_L, kKeySuper_R}, {kKeyAltGr, kKeyAltGr}
  };

  KeyModifierID id2 = kKeyModifierIDNull;
  uint32_t side = 0;
  switch (id) {
  case kKeyShift_L:
    id2 = kKeyModifierIDShift;
    side = 0;
    break;

  case kKeyShift_R:
    id2 = kKeyModifierIDShift;
    side = 1;
    break;

  case kKeyControl_L:
    id2 = kKeyModifierIDControl;
    side = 0;
    break;

  case kKeyControl_R:
    id2 = kKeyModifierIDControl;
    side = 1;
    break;

  case kKeyAlt_L:
    id2 = kKeyModifierIDAlt;
    side = 0;
    break;

  case kKeyAlt_R:
    id2 = kKeyModifierIDAlt;
    side = 1;
    break;

  case kKeyAltGr:
    id2 = kKeyModifierIDAltGr;
    side = 1; // there is only one alt gr key on the right side
    break;

  case kKeyMeta_L:
    id2 = kKeyModifierIDMeta;
    side = 0;
    break;

  case kKeyMeta_R:
    id2 = kKeyModifierIDMeta;
    side = 1;
    break;

  case kKeySuper_L:
    id2 = kKeyModifierIDSuper;
    side = 0;
    break;

  case kKeySuper_R:
    id2 = kKeyModifierIDSuper;
    side = 1;
    break;
  }

  if (id2 != kKeyModifierIDNull) {
    return s_translationTable[m_modifierTranslationTable[id2]][side];
  } else {
    return id;
  }
}

KeyModifierMask ServerProxy::translateModifierMask(KeyModifierMask mask) const
{
  static const KeyModifierMask s_masks[kKeyModifierIDLast] = {0x0000,          KeyModifierShift, KeyModifierControl,
                                                              KeyModifierAlt,  KeyModifierMeta,  KeyModifierSuper,
                                                              KeyModifierAltGr};

  KeyModifierMask newMask = mask & ~(KeyModifierShift | KeyModifierControl | KeyModifierAlt | KeyModifierMeta |
                                     KeyModifierSuper | KeyModifierAltGr);
  if ((mask & KeyModifierShift) != 0) {
    newMask |= s_masks[m_modifierTranslationTable[kKeyModifierIDShift]];
  }
  if ((mask & KeyModifierControl) != 0) {
    newMask |= s_masks[m_modifierTranslationTable[kKeyModifierIDControl]];
  }
  if ((mask & KeyModifierAlt) != 0) {
    newMask |= s_masks[m_modifierTranslationTable[kKeyModifierIDAlt]];
  }
  if ((mask & KeyModifierAltGr) != 0) {
    newMask |= s_masks[m_modifierTranslationTable[kKeyModifierIDAltGr]];
  }
  if ((mask & KeyModifierMeta) != 0) {
    newMask |= s_masks[m_modifierTranslationTable[kKeyModifierIDMeta]];
  }
  if ((mask & KeyModifierSuper) != 0) {
    newMask |= s_masks[m_modifierTranslationTable[kKeyModifierIDSuper]];
  }
  return newMask;
}

void ServerProxy::enter()
{
  // parse
  int16_t x;
  int16_t y;
  uint16_t mask;
  uint32_t seqNum;
  ProtocolUtil::readf(m_stream, kMsgCEnter + 4, &x, &y, &seqNum, &mask);
  LOG((CLOG_DEBUG1 "recv enter, %d,%d %d %04x", x, y, seqNum, mask));

  // discard old compressed mouse motion, if any
  m_compressMouse = false;
  m_compressMouseRelative = false;
  m_dxMouse = 0;
  m_dyMouse = 0;
  m_seqNum = seqNum;
  m_serverLanguage = "";
  m_isUserNotifiedAboutLanguageSyncError = false;

  // forward
  m_client->enter(x, y, seqNum, static_cast<KeyModifierMask>(mask), false);
}

void ServerProxy::leave()
{
  // parse
  LOG((CLOG_DEBUG1 "recv leave"));

  // send last mouse motion
  flushCompressedMouse();

  // forward
  m_client->leave();
}

void ServerProxy::setClipboard()
{
  // parse
  static std::string dataCached;
  ClipboardID id;
  uint32_t seq;

  int r = ClipboardChunk::assemble(m_stream, dataCached, id, seq);

  if (r == kStart) {
    size_t size = ClipboardChunk::getExpectedSize();
    LOG((CLOG_DEBUG "receiving clipboard %d size=%d", id, size));
  } else if (r == kFinish) {
    LOG((CLOG_DEBUG "received clipboard %d size=%d", id, dataCached.size()));

    // forward
    Clipboard clipboard;
    clipboard.unmarshall(dataCached, 0);
    m_client->setClipboard(id, &clipboard);

    LOG((CLOG_INFO "clipboard was updated"));
  }
}

void ServerProxy::grabClipboard()
{
  // parse
  ClipboardID id;
  uint32_t seqNum;
  ProtocolUtil::readf(m_stream, kMsgCClipboard + 4, &id, &seqNum);
  LOG((CLOG_DEBUG "recv grab clipboard %d", id));

  // validate
  if (id >= kClipboardEnd) {
    return;
  }

  // forward
  m_client->grabClipboard(id);
}

void ServerProxy::keyDown(uint16_t id, uint16_t mask, uint16_t button, const std::string &lang)
{
  // get mouse up to date
  flushCompressedMouse();
  setActiveServerLanguage(lang);

  // translate
  KeyID id2 = translateKey(static_cast<KeyID>(id));
  KeyModifierMask mask2 = translateModifierMask(static_cast<KeyModifierMask>(mask));
  if (id2 != static_cast<KeyID>(id) || mask2 != static_cast<KeyModifierMask>(mask))
    LOG((CLOG_DEBUG1 "key down translated to id=0x%08x, mask=0x%04x", id2, mask2));

  // forward
  m_client->keyDown(id2, mask2, button, lang);
}

void ServerProxy::keyRepeat()
{
  // get mouse up to date
  flushCompressedMouse();

  // parse
  uint16_t id;
  uint16_t mask;
  uint16_t count;
  uint16_t button;
  std::string lang;
  ProtocolUtil::readf(m_stream, kMsgDKeyRepeat + 4, &id, &mask, &count, &button, &lang);
  LOG(
      (CLOG_DEBUG1 "recv key repeat id=0x%08x, mask=0x%04x, count=%d, "
                   "button=0x%04x, lang=\"%s\"",
       id, mask, count, button, lang.c_str())
  );

  // translate
  KeyID id2 = translateKey(static_cast<KeyID>(id));
  KeyModifierMask mask2 = translateModifierMask(static_cast<KeyModifierMask>(mask));
  if (id2 != static_cast<KeyID>(id) || mask2 != static_cast<KeyModifierMask>(mask))
    LOG((CLOG_DEBUG1 "key repeat translated to id=0x%08x, mask=0x%04x", id2, mask2));

  // forward
  m_client->keyRepeat(id2, mask2, count, button, lang);
}

void ServerProxy::keyUp()
{
  // get mouse up to date
  flushCompressedMouse();

  // parse
  uint16_t id;
  uint16_t mask;
  uint16_t button;
  ProtocolUtil::readf(m_stream, kMsgDKeyUp + 4, &id, &mask, &button);
  LOG((CLOG_DEBUG1 "recv key up id=0x%08x, mask=0x%04x, button=0x%04x", id, mask, button));

  // translate
  KeyID id2 = translateKey(static_cast<KeyID>(id));
  KeyModifierMask mask2 = translateModifierMask(static_cast<KeyModifierMask>(mask));
  if (id2 != static_cast<KeyID>(id) || mask2 != static_cast<KeyModifierMask>(mask))
    LOG((CLOG_DEBUG1 "key up translated to id=0x%08x, mask=0x%04x", id2, mask2));

  // forward
  m_client->keyUp(id2, mask2, button);
}

void ServerProxy::mouseDown()
{
  // get mouse up to date
  flushCompressedMouse();

  // parse
  int8_t id;
  ProtocolUtil::readf(m_stream, kMsgDMouseDown + 4, &id);
  LOG((CLOG_DEBUG1 "recv mouse down id=%d", id));

  // forward
  m_client->mouseDown(static_cast<ButtonID>(id));
}

void ServerProxy::mouseUp()
{
  // get mouse up to date
  flushCompressedMouse();

  // parse
  int8_t id;
  ProtocolUtil::readf(m_stream, kMsgDMouseUp + 4, &id);
  LOG((CLOG_DEBUG1 "recv mouse up id=%d", id));

  // forward
  m_client->mouseUp(static_cast<ButtonID>(id));
}

void ServerProxy::mouseMove()
{
  // parse
  bool ignore;
  int16_t x;
  int16_t y;
  ProtocolUtil::readf(m_stream, kMsgDMouseMove + 4, &x, &y);

  // note if we should ignore the move
  ignore = m_ignoreMouse;

  // compress mouse motion events if more input follows
  if (!ignore && !m_compressMouse && m_stream->isReady()) {
    m_compressMouse = true;
  }

  // if compressing then ignore the motion but record it
  if (m_compressMouse) {
    m_compressMouseRelative = false;
    ignore = true;
    m_xMouse = x;
    m_yMouse = y;
    m_dxMouse = 0;
    m_dyMouse = 0;
  }
  LOG((CLOG_DEBUG2 "recv mouse move %d,%d", x, y));

  // forward
  if (!ignore) {
    m_client->mouseMove(x, y);
  }
}

void ServerProxy::mouseRelativeMove()
{
  // parse
  bool ignore;
  int16_t dx;
  int16_t dy;
  ProtocolUtil::readf(m_stream, kMsgDMouseRelMove + 4, &dx, &dy);

  // note if we should ignore the move
  ignore = m_ignoreMouse;

  // compress mouse motion events if more input follows
  if (!ignore && !m_compressMouseRelative && m_stream->isReady()) {
    m_compressMouseRelative = true;
  }

  // if compressing then ignore the motion but record it
  if (m_compressMouseRelative) {
    ignore = true;
    m_dxMouse += dx;
    m_dyMouse += dy;
  }
  LOG((CLOG_DEBUG2 "recv mouse relative move %d,%d", dx, dy));

  // forward
  if (!ignore) {
    m_client->mouseRelativeMove(dx, dy);
  }
}

void ServerProxy::mouseWheel()
{
  // get mouse up to date
  flushCompressedMouse();

  // parse
  int16_t xDelta;
  int16_t yDelta;
  ProtocolUtil::readf(m_stream, kMsgDMouseWheel + 4, &xDelta, &yDelta);
  LOG((CLOG_DEBUG2 "recv mouse wheel %+d,%+d", xDelta, yDelta));

  // forward
  m_client->mouseWheel(xDelta, yDelta);
}

void ServerProxy::screensaver()
{
  // parse
  int8_t on;
  ProtocolUtil::readf(m_stream, kMsgCScreenSaver + 4, &on);
  LOG((CLOG_DEBUG1 "recv screen saver on=%d", on));

  // forward
  m_client->screensaver(on != 0);
}

void ServerProxy::resetOptions()
{
  // parse
  LOG((CLOG_DEBUG1 "recv reset options"));

  // forward
  m_client->resetOptions();

  // reset keep alive
  setKeepAliveRate(kKeepAliveRate);

  // reset modifier translation table
  for (KeyModifierID id = 0; id < kKeyModifierIDLast; ++id) {
    m_modifierTranslationTable[id] = id;
  }
}

void ServerProxy::setOptions()
{
  // parse
  OptionsList options;
  ProtocolUtil::readf(m_stream, kMsgDSetOptions + 4, &options);
  LOG((CLOG_DEBUG1 "recv set options size=%d", options.size()));

  // forward
  m_client->setOptions(options);

  // update modifier table
  for (uint32_t i = 0, n = (uint32_t)options.size(); i < n; i += 2) {
    KeyModifierID id = kKeyModifierIDNull;
    if (options[i] == kOptionModifierMapForShift) {
      id = kKeyModifierIDShift;
    } else if (options[i] == kOptionModifierMapForControl) {
      id = kKeyModifierIDControl;
    } else if (options[i] == kOptionModifierMapForAlt) {
      id = kKeyModifierIDAlt;
    } else if (options[i] == kOptionModifierMapForAltGr) {
      id = kKeyModifierIDAltGr;
    } else if (options[i] == kOptionModifierMapForMeta) {
      id = kKeyModifierIDMeta;
    } else if (options[i] == kOptionModifierMapForSuper) {
      id = kKeyModifierIDSuper;
    } else if (options[i] == kOptionHeartbeat) {
      // update keep alive
      setKeepAliveRate(1.0e-3 * static_cast<double>(options[i + 1]));
    }

    if (id != kKeyModifierIDNull) {
      m_modifierTranslationTable[id] = static_cast<KeyModifierID>(options[i + 1]);
      LOG((CLOG_DEBUG1 "modifier %d mapped to %d", id, m_modifierTranslationTable[id]));
    }
  }
}

void ServerProxy::queryInfo()
{
  ClientInfo info;
  m_client->getShape(info.m_x, info.m_y, info.m_w, info.m_h);
  m_client->getCursorPos(info.m_mx, info.m_my);
  sendInfo(info);
}

void ServerProxy::infoAcknowledgment()
{
  LOG((CLOG_DEBUG1 "recv info acknowledgment"));
  m_ignoreMouse = false;
}

void ServerProxy::handleClipboardSendingEvent(const Event &event, void *)
{
  ClipboardChunk::send(m_stream, event.getDataObject());
}

void ServerProxy::secureInputNotification()
{
  std::string app;
  ProtocolUtil::readf(m_stream, kMsgDSecureInputNotification + 4, &app);
  LOG((CLOG_INFO "application \"%s\" is blocking the keyboard", app.c_str()));
}

void ServerProxy::setServerLanguages()
{
  std::string serverLanguages;
  ProtocolUtil::readf(m_stream, kMsgDLanguageSynchronisation + 4, &serverLanguages);
  m_languageManager.setRemoteLanguages(serverLanguages);
}

void ServerProxy::setActiveServerLanguage(const std::string &language)
{
  if (!language.empty() && std::strlen(language.c_str()) > 0) {
    if (m_serverLanguage != language) {
      m_isUserNotifiedAboutLanguageSyncError = false;
      m_serverLanguage = language;
    }

    if (!m_languageManager.isLanguageInstalled(m_serverLanguage)) {
      if (!m_isUserNotifiedAboutLanguageSyncError) {
        LOG((CLOG_WARN "current server language is not installed on client"));
        m_isUserNotifiedAboutLanguageSyncError = true;
      }
    } else {
      m_isUserNotifiedAboutLanguageSyncError = false;
    }
  } else {
    LOG((CLOG_DEBUG1 "active server language is empty"));
  }
}

void ServerProxy::checkMissedLanguages() const
{
  auto missedLanguages = m_languageManager.getMissedLanguages();
  if (!missedLanguages.empty()) {
    LOG(
        (CLOG_WARN "You need to install these languages on this computer and restart "
                   "Deskflow to enable support for multiple languages: %s",
         missedLanguages.c_str())
    );
  }
}