common/rfb/CMsgReader.cxx

/* Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
 * Copyright 2009-2014 Pierre Ossman 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 <stdio.h>
#include <rfb/msgTypes.h>
#include <rdr/InStream.h>
#include <rfb/Exception.h>
#include <rfb/util.h>
#include <rfb/CMsgHandler.h>
#include <rfb/CMsgReader.h>
#include <rfb/Decoder.h>

using namespace rfb;

CMsgReader::CMsgReader(CMsgHandler* handler_, rdr::InStream* is_)
  : imageBufIdealSize(0), handler(handler_), is(is_),
    imageBuf(0), imageBufSize(0), nUpdateRectsLeft(0)
{
  for (int i = 0; i <= encodingMax; i++) {
    decoders[i] = 0;
  }
}

CMsgReader::~CMsgReader()
{
  for (int i = 0; i <= encodingMax; i++) {
    delete decoders[i];
  }
  delete [] imageBuf;
}

void CMsgReader::readServerInit()
{
  int width = is->readU16();
  int height = is->readU16();
  handler->setDesktopSize(width, height);
  PixelFormat pf;
  pf.read(is);
  handler->setPixelFormat(pf);
  CharArray name(is->readString());
  handler->setName(name.buf);
  handler->serverInit();
}

void CMsgReader::readMsg()
{
  if (nUpdateRectsLeft == 0) {
    int type = is->readU8();

    switch (type) {
    case msgTypeSetColourMapEntries:
      readSetColourMapEntries();
      break;
    case msgTypeBell:
      readBell();
      break;
    case msgTypeServerCutText:
      readServerCutText();
      break;
    case msgTypeFramebufferUpdate:
      readFramebufferUpdate();
      break;
    case msgTypeServerFence:
      readFence();
      break;
    case msgTypeEndOfContinuousUpdates:
      readEndOfContinuousUpdates();
      break;
    default:
      fprintf(stderr, "unknown message type %d\n", type);
      throw Exception("unknown message type");
    }
  } else {
    int x = is->readU16();
    int y = is->readU16();
    int w = is->readU16();
    int h = is->readU16();
    int encoding = is->readS32();

    switch (encoding) {
    case pseudoEncodingLastRect:
      nUpdateRectsLeft = 1;     // this rectangle is the last one
      break;
    case pseudoEncodingCursor:
      readSetCursor(w, h, Point(x,y));
      break;
    case pseudoEncodingDesktopName:
      readSetDesktopName(x, y, w, h);
      break;
    case pseudoEncodingDesktopSize:
      handler->setDesktopSize(w, h);
      break;
    case pseudoEncodingExtendedDesktopSize:
      readExtendedDesktopSize(x, y, w, h);
      break;
    default:
      readRect(Rect(x, y, x+w, y+h), encoding);
      break;
    };

    nUpdateRectsLeft--;
    if (nUpdateRectsLeft == 0)
      handler->framebufferUpdateEnd();
  }
}

void CMsgReader::readSetColourMapEntries()
{
  is->skip(1);
  int firstColour = is->readU16();
  int nColours = is->readU16();
  rdr::U16Array rgbs(nColours * 3);
  for (int i = 0; i < nColours * 3; i++)
    rgbs.buf[i] = is->readU16();
  handler->setColourMapEntries(firstColour, nColours, rgbs.buf);
}

void CMsgReader::readBell()
{
  handler->bell();
}

void CMsgReader::readServerCutText()
{
  is->skip(3);
  rdr::U32 len = is->readU32();
  if (len > 256*1024) {
    is->skip(len);
    fprintf(stderr,"cut text too long (%d bytes) - ignoring\n",len);
    return;
  }
  CharArray ca(len+1);
  ca.buf[len] = 0;
  is->readBytes(ca.buf, len);
  handler->serverCutText(ca.buf, len);
}

void CMsgReader::readFence()
{
  rdr::U32 flags;
  rdr::U8 len;
  char data[64];

  is->skip(3);

  flags = is->readU32();

  len = is->readU8();
  if (len > sizeof(data)) {
    fprintf(stderr, "Ignoring fence with too large payload\n");
    is->skip(len);
    return;
  }

  is->readBytes(data, len);

  handler->fence(flags, len, data);
}

void CMsgReader::readEndOfContinuousUpdates()
{
  handler->endOfContinuousUpdates();
}

void CMsgReader::readFramebufferUpdate()
{
  is->skip(1);
  nUpdateRectsLeft = is->readU16();
  handler->framebufferUpdateStart();
}

void CMsgReader::readRect(const Rect& r, int encoding)
{
  if ((r.br.x > handler->cp.width) || (r.br.y > handler->cp.height)) {
    fprintf(stderr, "Rect too big: %dx%d at %d,%d exceeds %dx%d\n",
	    r.width(), r.height(), r.tl.x, r.tl.y,
            handler->cp.width, handler->cp.height);
    throw Exception("Rect too big");
  }

  if (r.is_empty())
    fprintf(stderr, "Warning: zero size rect\n");

  handler->beginRect(r, encoding);

  if (encoding == encodingCopyRect) {
    readCopyRect(r);
  } else {

    if (!Decoder::supported(encoding)) {
      fprintf(stderr, "Unknown rect encoding %d\n", encoding);
      throw Exception("Unknown rect encoding");
    }

    if (!decoders[encoding]) {
      decoders[encoding] = Decoder::createDecoder(encoding, this);
      if (!decoders[encoding]) {
        fprintf(stderr, "Unknown rect encoding %d\n", encoding);
        throw Exception("Unknown rect encoding");
      }
    }
    decoders[encoding]->readRect(r, handler);
  }

  handler->endRect(r, encoding);
}

void CMsgReader::readCopyRect(const Rect& r)
{
  int srcX = is->readU16();
  int srcY = is->readU16();
  handler->copyRect(r, srcX, srcY);
}

void CMsgReader::readSetCursor(int width, int height, const Point& hotspot)
{
  int data_len = width * height * (handler->cp.pf().bpp/8);
  int mask_len = ((width+7)/8) * height;
  rdr::U8Array data(data_len);
  rdr::U8Array mask(mask_len);

  is->readBytes(data.buf, data_len);
  is->readBytes(mask.buf, mask_len);

  handler->setCursor(width, height, hotspot, data.buf, mask.buf);
}

void CMsgReader::readSetDesktopName(int x, int y, int w, int h)
{
  char* name = is->readString();

  if (x || y || w || h) {
    fprintf(stderr, "Ignoring DesktopName rect with non-zero position/size\n");
  } else {
    handler->setName(name);
  }

  delete [] name;
}

void CMsgReader::readExtendedDesktopSize(int x, int y, int w, int h)
{
  unsigned int screens, i;
  rdr::U32 id, flags;
  int sx, sy, sw, sh;
  ScreenSet layout;

  screens = is->readU8();
  is->skip(3);

  for (i = 0;i < screens;i++) {
    id = is->readU32();
    sx = is->readU16();
    sy = is->readU16();
    sw = is->readU16();
    sh = is->readU16();
    flags = is->readU32();

    layout.add_screen(Screen(id, sx, sy, sw, sh, flags));
  }

  handler->setExtendedDesktopSize(x, y, w, h, layout);
}

rdr::U8* CMsgReader::getImageBuf(int required, int requested, int* nPixels)
{
  int requiredBytes = required * (handler->cp.pf().bpp / 8);
  int requestedBytes = requested * (handler->cp.pf().bpp / 8);
  int size = requestedBytes;
  if (size > imageBufIdealSize) size = imageBufIdealSize;

  if (size < requiredBytes)
    size = requiredBytes;

  if (imageBufSize < size) {
    imageBufSize = size;
    delete [] imageBuf;
    imageBuf = new rdr::U8[imageBufSize];
  }
  if (nPixels)
    *nPixels = imageBufSize / (handler->cp.pf().bpp / 8);
  return imageBuf;
}

int CMsgReader::bpp()
{
  return handler->cp.pf().bpp;
}