unix/x0vncserver/XDesktop.cxx

/* Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
 * Copyright (C) 2004-2008 Constantin Kaplinsky.  All Rights Reserved.
 * Copyright 2017 Peter Astrand <astrand@cendio.se> for Cendio AB
 *    
 * This is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this software; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
 * USA.
 */

#include <x0vncserver/XDesktop.h>

#include <X11/XKBlib.h>
#ifdef HAVE_XTEST
#include <X11/extensions/XTest.h>
#endif
#ifdef HAVE_XDAMAGE
#include <X11/extensions/Xdamage.h>
#endif
#ifdef HAVE_XFIXES
#include <X11/extensions/Xfixes.h>
#endif

#include <x0vncserver/Geometry.h>
#include <x0vncserver/XPixelBuffer.h>

using namespace rfb;

extern const unsigned short code_map_qnum_to_xorgevdev[];
extern const unsigned int code_map_qnum_to_xorgevdev_len;

extern const unsigned short code_map_qnum_to_xorgkbd[];
extern const unsigned int code_map_qnum_to_xorgkbd_len;

BoolParameter useShm("UseSHM", "Use MIT-SHM extension if available", true);
BoolParameter rawKeyboard("RawKeyboard",
                          "Send keyboard events straight through and "
                          "avoid mapping them to the current keyboard "
                          "layout", false);

static rfb::LogWriter vlog("XDesktop");

// order is important as it must match RFB extension
static const char * ledNames[XDESKTOP_N_LEDS] = {
  "Scroll Lock", "Num Lock", "Caps Lock"
};

XDesktop::XDesktop(Display* dpy_, Geometry *geometry_)
  : dpy(dpy_), geometry(geometry_), pb(0), server(0),
    oldButtonMask(0), haveXtest(false), haveDamage(false),
    maxButtons(0), running(false), ledMasks(), ledState(0),
    codeMap(0), codeMapLen(0)
{
  int major, minor;

  int xkbOpcode, xkbErrorBase;

  major = XkbMajorVersion;
  minor = XkbMinorVersion;
  if (!XkbQueryExtension(dpy, &xkbOpcode, &xkbEventBase,
                         &xkbErrorBase, &major, &minor)) {
    vlog.error("XKEYBOARD extension not present");
    throw Exception();
  }

  XkbSelectEvents(dpy, XkbUseCoreKbd, XkbIndicatorStateNotifyMask,
                  XkbIndicatorStateNotifyMask);

  // figure out bit masks for the indicators we are interested in
  for (int i = 0; i < XDESKTOP_N_LEDS; i++) {
    Atom a;
    int shift;
    Bool on;

    a = XInternAtom(dpy, ledNames[i], True);
    if (!a || !XkbGetNamedIndicator(dpy, a, &shift, &on, NULL, NULL))
      continue;

    ledMasks[i] = 1u << shift;
    vlog.debug("Mask for '%s' is 0x%x", ledNames[i], ledMasks[i]);
    if (on)
      ledState |= 1u << i;
  }

  // X11 unfortunately uses keyboard driver specific keycodes and provides no
  // direct way to query this, so guess based on the keyboard mapping
  XkbDescPtr desc = XkbGetKeyboard(dpy, XkbAllComponentsMask, XkbUseCoreKbd);
  if (desc && desc->names) {
    char *keycodes = XGetAtomName(dpy, desc->names->keycodes);

    if (keycodes) {
      if (strncmp("evdev", keycodes, strlen("evdev")) == 0) {
        codeMap = code_map_qnum_to_xorgevdev;
        codeMapLen = code_map_qnum_to_xorgevdev_len;
        vlog.info("Using evdev codemap\n");
      } else if (strncmp("xfree86", keycodes, strlen("xfree86")) == 0) {
        codeMap = code_map_qnum_to_xorgkbd;
        codeMapLen = code_map_qnum_to_xorgkbd_len;
        vlog.info("Using xorgkbd codemap\n");
      } else {
        vlog.info("Unknown keycode '%s', no codemap\n", keycodes);
      }
      XFree(keycodes);
    } else {
      vlog.debug("Unable to get keycode map\n");
    }

    XkbFreeKeyboard(desc, XkbAllComponentsMask, True);
  }

#ifdef HAVE_XTEST
  int xtestEventBase;
  int xtestErrorBase;

  if (XTestQueryExtension(dpy, &xtestEventBase,
                          &xtestErrorBase, &major, &minor)) {
    XTestGrabControl(dpy, True);
    vlog.info("XTest extension present - version %d.%d",major,minor);
    haveXtest = true;
  } else {
#endif
    vlog.info("XTest extension not present");
    vlog.info("Unable to inject events or display while server is grabbed");
#ifdef HAVE_XTEST
  }
#endif

#ifdef HAVE_XDAMAGE
  int xdamageErrorBase;

  if (XDamageQueryExtension(dpy, &xdamageEventBase, &xdamageErrorBase)) {
    haveDamage = true;
  } else {
#endif
    vlog.info("DAMAGE extension not present");
    vlog.info("Will have to poll screen for changes");
#ifdef HAVE_XDAMAGE
  }
#endif

#ifdef HAVE_XFIXES
  int xfixesErrorBase;

  if (XFixesQueryExtension(dpy, &xfixesEventBase, &xfixesErrorBase)) {
    XFixesSelectCursorInput(dpy, DefaultRootWindow(dpy),
                            XFixesDisplayCursorNotifyMask);
  } else {
#endif
    vlog.info("XFIXES extension not present");
    vlog.info("Will not be able to display cursors");
#ifdef HAVE_XFIXES
  }
#endif

  TXWindow::setGlobalEventHandler(this);
}

XDesktop::~XDesktop() {
  if (running)
    stop();
}


void XDesktop::poll() {
  if (pb and not haveDamage)
    pb->poll(server);
  if (running) {
    Window root, child;
    int x, y, wx, wy;
    unsigned int mask;
    XQueryPointer(dpy, DefaultRootWindow(dpy), &root, &child,
                  &x, &y, &wx, &wy, &mask);
    server->setCursorPos(rfb::Point(x, y));
  }
}


void XDesktop::start(VNCServer* vs) {

  // Determine actual number of buttons of the X pointer device.
  unsigned char btnMap[8];
  int numButtons = XGetPointerMapping(dpy, btnMap, 8);
  maxButtons = (numButtons > 8) ? 8 : numButtons;
  vlog.info("Enabling %d button%s of X pointer device",
            maxButtons, (maxButtons != 1) ? "s" : "");

  // Create an ImageFactory instance for producing Image objects.
  ImageFactory factory((bool)useShm);

  // Create pixel buffer and provide it to the server object.
  pb = new XPixelBuffer(dpy, factory, geometry->getRect());
  vlog.info("Allocated %s", pb->getImage()->classDesc());

  server = (VNCServerST *)vs;
  server->setPixelBuffer(pb);

#ifdef HAVE_XDAMAGE
  if (haveDamage) {
    damage = XDamageCreate(dpy, DefaultRootWindow(dpy),
                           XDamageReportRawRectangles);
  }
#endif

#ifdef HAVE_XFIXES
  setCursor();
#endif

  server->setLEDState(ledState);

  running = true;
}

void XDesktop::stop() {
  running = false;

#ifdef HAVE_XDAMAGE
  if (haveDamage)
    XDamageDestroy(dpy, damage);
#endif

  server->setPixelBuffer(0);
  server = 0;

  delete pb;
  pb = 0;
}

bool XDesktop::isRunning() {
  return running;
}

void XDesktop::pointerEvent(const Point& pos, int buttonMask) {
#ifdef HAVE_XTEST
  if (!haveXtest) return;
  XTestFakeMotionEvent(dpy, DefaultScreen(dpy),
                       geometry->offsetLeft() + pos.x,
                       geometry->offsetTop() + pos.y,
                       CurrentTime);
  if (buttonMask != oldButtonMask) {
    for (int i = 0; i < maxButtons; i++) {
      if ((buttonMask ^ oldButtonMask) & (1<<i)) {
        if (buttonMask & (1<<i)) {
          XTestFakeButtonEvent(dpy, i+1, True, CurrentTime);
        } else {
          XTestFakeButtonEvent(dpy, i+1, False, CurrentTime);
        }
      }
    }
  }
  oldButtonMask = buttonMask;
#endif
}

#ifdef HAVE_XTEST
KeyCode XDesktop::XkbKeysymToKeycode(Display* dpy, KeySym keysym) {
  XkbDescPtr xkb;
  XkbStateRec state;
  unsigned keycode;

  xkb = XkbGetMap(dpy, XkbAllComponentsMask, XkbUseCoreKbd);
  if (!xkb)
    return 0;

  XkbGetState(dpy, XkbUseCoreKbd, &state);

  for (keycode = xkb->min_key_code;
       keycode <= xkb->max_key_code;
       keycode++) {
    KeySym cursym;
    unsigned int mods, out_mods;
    // XkbStateFieldFromRec() doesn't work properly because
    // state.lookup_mods isn't properly updated, so we do this manually
    mods = XkbBuildCoreState(XkbStateMods(&state), state.group);
    XkbTranslateKeyCode(xkb, keycode, mods, &out_mods, &cursym);
    if (cursym == keysym)
      break;
  }

  if (keycode > xkb->max_key_code)
    keycode = 0;

  XkbFreeKeyboard(xkb, XkbAllComponentsMask, True);

  return keycode;
}
#endif

void XDesktop::keyEvent(rdr::U32 keysym, rdr::U32 xtcode, bool down) {
#ifdef HAVE_XTEST
  int keycode = 0;

  if (!haveXtest)
    return;

  // Use scan code if provided and mapping exists
  if (codeMap && rawKeyboard && xtcode < codeMapLen)
      keycode = codeMap[xtcode];

  if (!keycode) {
    if (pressedKeys.find(keysym) != pressedKeys.end())
      keycode = pressedKeys[keysym];
    else {
      // XKeysymToKeycode() doesn't respect state, so we have to use
      // something slightly more complex
      keycode = XkbKeysymToKeycode(dpy, keysym);
    }
  }

  if (!keycode)
    return;

  if (down)
    pressedKeys[keysym] = keycode;
  else
    pressedKeys.erase(keysym);

  XTestFakeKeyEvent(dpy, keycode, down, CurrentTime);
#endif
}

void XDesktop::clientCutText(const char* str, int len) {
}


bool XDesktop::handleGlobalEvent(XEvent* ev) {
  if (ev->type == xkbEventBase + XkbEventCode) {
    XkbEvent *kb = (XkbEvent *)ev;

    if (kb->any.xkb_type != XkbIndicatorStateNotify)
      return false;

    vlog.debug("Got indicator update, mask is now 0x%x", kb->indicators.state);

    ledState = 0;
    for (int i = 0; i < XDESKTOP_N_LEDS; i++) {
      if (kb->indicators.state & ledMasks[i])
        ledState |= 1u << i;
    }

    if (running)
      server->setLEDState(ledState);

    return true;
#ifdef HAVE_XDAMAGE
  } else if (ev->type == xdamageEventBase) {
    XDamageNotifyEvent* dev;
    Rect rect;

    if (!running)
      return true;

    dev = (XDamageNotifyEvent*)ev;
    rect.setXYWH(dev->area.x, dev->area.y, dev->area.width, dev->area.height);
    server->add_changed(rect);

    return true;
#endif
#ifdef HAVE_XFIXES
  } else if (ev->type == xfixesEventBase + XFixesCursorNotify) {
    XFixesCursorNotifyEvent* cev;

    if (!running)
      return true;

    cev = (XFixesCursorNotifyEvent*)ev;

    if (cev->subtype != XFixesDisplayCursorNotify)
      return false;

    return setCursor();
#endif
  }

  return false;
}

bool XDesktop::setCursor()
{
  XFixesCursorImage *cim;

  cim = XFixesGetCursorImage(dpy);
  if (cim == NULL)
    return false;

  // Copied from XserverDesktop::setCursor() in
  // unix/xserver/hw/vnc/XserverDesktop.cc and adapted to
  // handle long -> U32 conversion for 64-bit Xlib
  rdr::U8* cursorData;
  rdr::U8 *out;
  const unsigned long *pixels;

  cursorData = new rdr::U8[cim->width * cim->height * 4];

  // Un-premultiply alpha
  pixels = cim->pixels;
  out = cursorData;
  for (int y = 0; y < cim->height; y++) {
    for (int x = 0; x < cim->width; x++) {
      rdr::U8 alpha;
      rdr::U32 pixel = *pixels++;
      rdr::U8 *in = (rdr::U8 *) &pixel;

      alpha = in[3];
      if (alpha == 0)
        alpha = 1; // Avoid division by zero

      *out++ = (unsigned)*in++ * 255/alpha;
      *out++ = (unsigned)*in++ * 255/alpha;
      *out++ = (unsigned)*in++ * 255/alpha;
      *out++ = *in++;
    }
  }

  try {
    server->setCursor(cim->width, cim->height, Point(cim->xhot, cim->yhot),
                      cursorData);
  } catch (rdr::Exception& e) {
    vlog.error("XserverDesktop::setCursor: %s",e.str());
  }

  delete [] cursorData;
  XFree(cim);
  return true;
}