libtdevnc/libvncserver/rfbserver.c

/*
 * rfbserver.c - deal with server-side of the RFB protocol.
 */

/*
 *  Copyright (C) 2002 RealVNC Ltd.
 *  OSXvnc Copyright (C) 2001 Dan McGuirk <mcguirk@incompleteness.net>.
 *  Original Xvnc code Copyright (C) 1999 AT&T Laboratories Cambridge.  
 *  All Rights Reserved.
 *
 *  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 <string.h>
#include <rfb/rfb.h>
#include <rfb/rfbregion.h>

#ifdef LIBVNCSERVER_HAVE_FCNTL_H
#include <fcntl.h>
#endif

#ifdef WIN32
#define write(sock,buf,len) send(sock,buf,len,0)
#else
#ifdef LIBVNCSERVER_HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <pwd.h>
#ifdef LIBVNCSERVER_HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef LIBVNCSERVER_HAVE_NETINET_IN_H
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#endif
#endif

#ifdef CORBA
#include <vncserverctrl.h>
#endif

#ifdef DEBUGPROTO
#undef DEBUGPROTO
#define DEBUGPROTO(x) x
#else
#define DEBUGPROTO(x)
#endif

/* from cursor.c */

void rfbShowCursor(rfbClientPtr cl);
void rfbHideCursor(rfbClientPtr cl);
void rfbRedrawAfterHideCursor(rfbClientPtr cl,sraRegionPtr updateRegion);

static void rfbProcessClientProtocolVersion(rfbClientPtr cl);
static void rfbProcessClientNormalMessage(rfbClientPtr cl);
static void rfbProcessClientInitMessage(rfbClientPtr cl);

#ifdef LIBVNCSERVER_HAVE_LIBPTHREAD
void rfbIncrClientRef(rfbClientPtr cl)
{
  LOCK(cl->refCountMutex);
  cl->refCount++;
  UNLOCK(cl->refCountMutex);
}

void rfbDecrClientRef(rfbClientPtr cl)
{
  LOCK(cl->refCountMutex);
  cl->refCount--;
  if(cl->refCount<=0) /* just to be sure also < 0 */
    TSIGNAL(cl->deleteCond);
  UNLOCK(cl->refCountMutex);
}
#else
void rfbIncrClientRef(rfbClientPtr cl) {}
void rfbDecrClientRef(rfbClientPtr cl) {}
#endif

#ifdef LIBVNCSERVER_HAVE_LIBPTHREAD
MUTEX(rfbClientListMutex);
#endif

struct rfbClientIterator {
  rfbClientPtr next;
  rfbScreenInfoPtr screen;
};

void
rfbClientListInit(rfbScreenInfoPtr rfbScreen)
{
    if(sizeof(rfbBool)!=1) {
        /* a sanity check */
        fprintf(stderr,"rfbBool's size is not 1 (%d)!\n",sizeof(rfbBool));
	/* we cannot continue, because rfbBool is supposed to be char everywhere */
	exit(1);
    }
    rfbScreen->clientHead = NULL;
    INIT_MUTEX(rfbClientListMutex);
}

rfbClientIteratorPtr
rfbGetClientIterator(rfbScreenInfoPtr rfbScreen)
{
  rfbClientIteratorPtr i =
    (rfbClientIteratorPtr)malloc(sizeof(struct rfbClientIterator));
  i->next = 0;
  i->screen = rfbScreen;
  return i;
}

rfbClientPtr
rfbClientIteratorHead(rfbClientIteratorPtr i)
{
#ifdef LIBVNCSERVER_HAVE_LIBPTHREAD
  if(i->next != 0) {
    rfbDecrClientRef(i->next);
    rfbIncrClientRef(i->screen->clientHead);
  }
#endif
  LOCK(rfbClientListMutex);
  i->next = i->screen->clientHead;
  UNLOCK(rfbClientListMutex);
  return i->next;
}

rfbClientPtr
rfbClientIteratorNext(rfbClientIteratorPtr i)
{
  if(i->next == 0) {
    LOCK(rfbClientListMutex);
    i->next = i->screen->clientHead;
    UNLOCK(rfbClientListMutex);
  } else {
    IF_PTHREADS(rfbClientPtr cl = i->next);
    i->next = i->next->next;
    IF_PTHREADS(rfbDecrClientRef(cl));
  }

#ifdef LIBVNCSERVER_HAVE_LIBPTHREAD
    while(i->next && i->next->sock<0)
      i->next = i->next->next;
    if(i->next)
      rfbIncrClientRef(i->next);
#endif

    return i->next;
}

void
rfbReleaseClientIterator(rfbClientIteratorPtr iterator)
{
  IF_PTHREADS(if(iterator->next) rfbDecrClientRef(iterator->next));
  free(iterator);
}


/*
 * rfbNewClientConnection is called from sockets.c when a new connection
 * comes in.
 */

void
rfbNewClientConnection(rfbScreen,sock)
    rfbScreenInfoPtr rfbScreen;
    int sock;
{
    rfbClientPtr cl;

    cl = rfbNewClient(rfbScreen,sock);
#ifdef CORBA
    if(cl!=NULL)
      newConnection(cl, (KEYBOARD_DEVICE|POINTER_DEVICE),1,1,1);
#endif
}


/*
 * rfbReverseConnection is called by the CORBA stuff to make an outward
 * connection to a "listening" RFB client.
 */

rfbClientPtr
rfbReverseConnection(rfbScreen,host, port)
    rfbScreenInfoPtr rfbScreen;
    char *host;
    int port;
{
    int sock;
    rfbClientPtr cl;

    if ((sock = rfbConnect(rfbScreen, host, port)) < 0)
        return (rfbClientPtr)NULL;

    cl = rfbNewClient(rfbScreen, sock);

    if (cl) {
        cl->reverseConnection = TRUE;
    }

    return cl;
}


/*
 * rfbNewClient is called when a new connection has been made by whatever
 * means.
 */

rfbClientPtr
rfbNewTCPOrUDPClient(rfbScreen,sock,isUDP)
    rfbScreenInfoPtr rfbScreen;
    int sock;
    rfbBool isUDP;
{
    rfbProtocolVersionMsg pv;
    rfbClientIteratorPtr iterator;
    rfbClientPtr cl,cl_;
    struct sockaddr_in addr;
    size_t addrlen = sizeof(struct sockaddr_in);

    cl = (rfbClientPtr)calloc(sizeof(rfbClientRec),1);

    cl->screen = rfbScreen;
    cl->sock = sock;
    cl->viewOnly = FALSE;

    rfbResetStats(cl);

    if(isUDP) {
      rfbLog(" accepted UDP client\n");
    } else {
      int one=1;

      getpeername(sock, (struct sockaddr *)&addr, &addrlen);
      cl->host = strdup(inet_ntoa(addr.sin_addr));

      rfbLog("  other clients:\n");
      iterator = rfbGetClientIterator(rfbScreen);
      while ((cl_ = rfbClientIteratorNext(iterator)) != NULL) {
        rfbLog("     %s\n",cl_->host);
      }
      rfbReleaseClientIterator(iterator);

#ifndef WIN32
      if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) {
	rfbLogPerror("fcntl failed");
	close(sock);
	return NULL;
      }
#endif

      if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
		     (char *)&one, sizeof(one)) < 0) {
	rfbLogPerror("setsockopt failed");
	close(sock);
	return NULL;
      }

      FD_SET(sock,&(rfbScreen->allFds));
		rfbScreen->maxFd = max(sock,rfbScreen->maxFd);

      INIT_MUTEX(cl->outputMutex);
      INIT_MUTEX(cl->refCountMutex);
      INIT_COND(cl->deleteCond);

      cl->state = RFB_PROTOCOL_VERSION;

      cl->reverseConnection = FALSE;
      cl->readyForSetColourMapEntries = FALSE;
      cl->useCopyRect = FALSE;
      cl->preferredEncoding = -1;
      cl->correMaxWidth = 48;
      cl->correMaxHeight = 48;
#ifdef LIBVNCSERVER_HAVE_LIBZ
      cl->zrleData = 0;
#endif

      cl->copyRegion = sraRgnCreate();
      cl->copyDX = 0;
      cl->copyDY = 0;
   
      cl->modifiedRegion =
	sraRgnCreateRect(0,0,rfbScreen->width,rfbScreen->height);

      INIT_MUTEX(cl->updateMutex);
      INIT_COND(cl->updateCond);

      cl->requestedRegion = sraRgnCreate();

      cl->format = cl->screen->serverFormat;
      cl->translateFn = rfbTranslateNone;
      cl->translateLookupTable = NULL;

      LOCK(rfbClientListMutex);

      IF_PTHREADS(cl->refCount = 0);
      cl->next = rfbScreen->clientHead;
      cl->prev = NULL;
      if (rfbScreen->clientHead)
        rfbScreen->clientHead->prev = cl;

      rfbScreen->clientHead = cl;
      UNLOCK(rfbClientListMutex);

#ifdef LIBVNCSERVER_HAVE_LIBJPEG
      cl->tightCompressLevel = TIGHT_DEFAULT_COMPRESSION;
      cl->tightQualityLevel = -1;
      {
	int i;
	for (i = 0; i < 4; i++)
          cl->zsActive[i] = FALSE;
      }
#endif

      cl->enableCursorShapeUpdates = FALSE;
      cl->enableCursorPosUpdates = FALSE;
      cl->useRichCursorEncoding = FALSE;
      cl->enableLastRectEncoding = FALSE;
      cl->cursorX = rfbScreen->cursorX;
      cl->cursorY = rfbScreen->cursorY;
      cl->useNewFBSize = FALSE;

#ifdef LIBVNCSERVER_HAVE_LIBZ
      cl->compStreamInited = FALSE;
      cl->compStream.total_in = 0;
      cl->compStream.total_out = 0;
      cl->compStream.zalloc = Z_NULL;
      cl->compStream.zfree = Z_NULL;
      cl->compStream.opaque = Z_NULL;

      cl->zlibCompressLevel = 5;
#endif

      cl->progressiveSliceY = 0;

      sprintf(pv,rfbProtocolVersionFormat,rfbProtocolMajorVersion,
	      rfbProtocolMinorVersion);

      if (rfbWriteExact(cl, pv, sz_rfbProtocolVersionMsg) < 0) {
        rfbLogPerror("rfbNewClient: write");
        rfbCloseClient(cl);
	rfbClientConnectionGone(cl);
        return NULL;
      }
    }

    cl->clientData = NULL;
    cl->clientGoneHook = rfbDoNothingWithClient;
    switch (cl->screen->newClientHook(cl)) {
    case RFB_CLIENT_ON_HOLD:
	    cl->onHold = TRUE;
	    break;
    case RFB_CLIENT_ACCEPT:
	    cl->onHold = FALSE;
	    break;
    case RFB_CLIENT_REFUSE:
	    rfbCloseClient(cl);
	    rfbClientConnectionGone(cl);
	    cl = NULL;
	    break;
    }
    return cl;
}

rfbClientPtr
rfbNewClient(rfbScreen,sock)
    rfbScreenInfoPtr rfbScreen;
    int sock;
{
  return(rfbNewTCPOrUDPClient(rfbScreen,sock,FALSE));
}

rfbClientPtr
rfbNewUDPClient(rfbScreen)
     rfbScreenInfoPtr rfbScreen;
{
  return((rfbScreen->udpClient=
	  rfbNewTCPOrUDPClient(rfbScreen,rfbScreen->udpSock,TRUE)));
}

/*
 * rfbClientConnectionGone is called from sockets.c just after a connection
 * has gone away.
 */

void
rfbClientConnectionGone(cl)
     rfbClientPtr cl;
{
    int i;

    LOCK(rfbClientListMutex);

    if (cl->prev)
        cl->prev->next = cl->next;
    else
        cl->screen->clientHead = cl->next;
    if (cl->next)
        cl->next->prev = cl->prev;

    if(cl->sock>0)
	close(cl->sock);

#ifdef LIBVNCSERVER_HAVE_LIBZ
    FreeZrleData(cl);
#endif

#ifdef LIBVNCSERVER_HAVE_LIBPTHREAD
    if(cl->screen->backgroundLoop != FALSE)
      do {
	LOCK(cl->refCountMutex);
	i=cl->refCount;
	UNLOCK(cl->refCountMutex);
	if(i>0)
	  WAIT(cl->deleteCond,cl->refCountMutex);
      } while(i>0);
#endif

    UNLOCK(rfbClientListMutex);

    if(cl->sock>=0)
       FD_CLR(cl->sock,&(cl->screen->allFds));

    cl->clientGoneHook(cl);

    rfbLog("Client %s gone\n",cl->host);
    free(cl->host);

#ifdef LIBVNCSERVER_HAVE_LIBZ
    /* Release the compression state structures if any. */
    if ( cl->compStreamInited ) {
	deflateEnd( &(cl->compStream) );
    }

#ifdef LIBVNCSERVER_HAVE_LIBJPEG
    for (i = 0; i < 4; i++) {
	if (cl->zsActive[i])
	    deflateEnd(&cl->zsStruct[i]);
    }
#endif
#endif

    if (cl->screen->pointerClient == cl)
        cl->screen->pointerClient = 0;

    sraRgnDestroy(cl->modifiedRegion);
    sraRgnDestroy(cl->requestedRegion);
    sraRgnDestroy(cl->copyRegion);

    if (cl->translateLookupTable) free(cl->translateLookupTable);

    TINI_COND(cl->updateCond);
    TINI_MUTEX(cl->updateMutex);

    LOCK(cl->outputMutex);
    TINI_MUTEX(cl->outputMutex);

#ifdef CORBA
    destroyConnection(cl);
#endif

    rfbPrintStats(cl);

    free(cl);
}


/*
 * rfbProcessClientMessage is called when there is data to read from a client.
 */

void
rfbProcessClientMessage(cl)
     rfbClientPtr cl;
{
    switch (cl->state) {
    case RFB_PROTOCOL_VERSION:
        rfbProcessClientProtocolVersion(cl);
        return;
    case RFB_AUTHENTICATION:
        rfbAuthProcessClientMessage(cl);
        return;
    case RFB_INITIALISATION:
        rfbProcessClientInitMessage(cl);
        return;
    default:
        rfbProcessClientNormalMessage(cl);
        return;
    }
}


/*
 * rfbProcessClientProtocolVersion is called when the client sends its
 * protocol version.
 */

static void
rfbProcessClientProtocolVersion(cl)
    rfbClientPtr cl;
{
    rfbProtocolVersionMsg pv;
    int n, major_, minor_;
    char failureReason[256];

    if ((n = rfbReadExact(cl, pv, sz_rfbProtocolVersionMsg)) <= 0) {
        if (n == 0)
            rfbLog("rfbProcessClientProtocolVersion: client gone\n");
        else
            rfbLogPerror("rfbProcessClientProtocolVersion: read");
        rfbCloseClient(cl);
        return;
    }

    pv[sz_rfbProtocolVersionMsg] = 0;
    if (sscanf(pv,rfbProtocolVersionFormat,&major_,&minor_) != 2) {
        char name[1024]; 
	if(sscanf(pv,"RFB %03d.%03d %1024s\n",&major_,&minor_,name) != 3) {
	    rfbErr("rfbProcessClientProtocolVersion: not a valid RFB client\n");
	    rfbCloseClient(cl);
	    return;
	}
	free(cl->host);
	cl->host=strdup(name);
    }
    rfbLog("Protocol version %d.%d\n", major_, minor_);

    if (major_ != rfbProtocolMajorVersion) {
        /* Major version mismatch - send a ConnFailed message */

        rfbErr("Major version mismatch\n");
        sprintf(failureReason,
                "RFB protocol version mismatch - server %d.%d, client %d.%d",
                rfbProtocolMajorVersion,rfbProtocolMinorVersion,major_,minor_);
        rfbClientConnFailed(cl, failureReason);
        return;
    }

    if (minor_ != rfbProtocolMinorVersion) {
        /* Minor version mismatch - warn but try to continue */
        rfbLog("Ignoring minor version mismatch\n");
    }

    rfbAuthNewClient(cl);
}


/*
 * rfbClientConnFailed is called when a client connection has failed either
 * because it talks the wrong protocol or it has failed authentication.
 */

void
rfbClientConnFailed(cl, reason)
    rfbClientPtr cl;
    char *reason;
{
    char *buf;
    int len = strlen(reason);

    buf = (char *)malloc(8 + len);
    ((uint32_t *)buf)[0] = Swap32IfLE(rfbConnFailed);
    ((uint32_t *)buf)[1] = Swap32IfLE(len);
    memcpy(buf + 8, reason, len);

    if (rfbWriteExact(cl, buf, 8 + len) < 0)
        rfbLogPerror("rfbClientConnFailed: write");
    free(buf);
    rfbCloseClient(cl);
}


/*
 * rfbProcessClientInitMessage is called when the client sends its
 * initialisation message.
 */

static void
rfbProcessClientInitMessage(cl)
    rfbClientPtr cl;
{
    rfbClientInitMsg ci;
    char buf[256];
    rfbServerInitMsg *si = (rfbServerInitMsg *)buf;
    int len, n;
    rfbClientIteratorPtr iterator;
    rfbClientPtr otherCl;

    if ((n = rfbReadExact(cl, (char *)&ci,sz_rfbClientInitMsg)) <= 0) {
        if (n == 0)
            rfbLog("rfbProcessClientInitMessage: client gone\n");
        else
            rfbLogPerror("rfbProcessClientInitMessage: read");
        rfbCloseClient(cl);
        return;
    }

    memset(buf,0,256);

    si->framebufferWidth = Swap16IfLE(cl->screen->width);
    si->framebufferHeight = Swap16IfLE(cl->screen->height);
    si->format = cl->screen->serverFormat;
    si->format.redMax = Swap16IfLE(si->format.redMax);
    si->format.greenMax = Swap16IfLE(si->format.greenMax);
    si->format.blueMax = Swap16IfLE(si->format.blueMax);

    strncpy(buf + sz_rfbServerInitMsg, cl->screen->desktopName, 127);
    len = strlen(buf + sz_rfbServerInitMsg);
    si->nameLength = Swap32IfLE(len);

    if (rfbWriteExact(cl, buf, sz_rfbServerInitMsg + len) < 0) {
        rfbLogPerror("rfbProcessClientInitMessage: write");
        rfbCloseClient(cl);
        return;
    }

    cl->state = RFB_NORMAL;

    if (!cl->reverseConnection &&
                        (cl->screen->neverShared || (!cl->screen->alwaysShared && !ci.shared))) {

        if (cl->screen->dontDisconnect) {
            iterator = rfbGetClientIterator(cl->screen);
            while ((otherCl = rfbClientIteratorNext(iterator)) != NULL) {
                if ((otherCl != cl) && (otherCl->state == RFB_NORMAL)) {
                    rfbLog("-dontdisconnect: Not shared & existing client\n");
                    rfbLog("  refusing new client %s\n", cl->host);
                    rfbCloseClient(cl);
                    rfbReleaseClientIterator(iterator);
                    return;
                }
            }
            rfbReleaseClientIterator(iterator);
        } else {
            iterator = rfbGetClientIterator(cl->screen);
            while ((otherCl = rfbClientIteratorNext(iterator)) != NULL) {
                if ((otherCl != cl) && (otherCl->state == RFB_NORMAL)) {
                    rfbLog("Not shared - closing connection to client %s\n",
                           otherCl->host);
                    rfbCloseClient(otherCl);
                }
            }
            rfbReleaseClientIterator(iterator);
        }
    }
}

static rfbBool rectSwapIfLEAndClip(uint16_t* x,uint16_t* y,uint16_t* w,uint16_t* h,
		rfbScreenInfoPtr screen)
{
	*x=Swap16IfLE(*x);
	*y=Swap16IfLE(*y);
	*w=Swap16IfLE(*w);
	*h=Swap16IfLE(*h);
	if(*w>screen->width-*x)
		*w=screen->width-*x;
	/* possible underflow */
	if(*w>screen->width-*x)
		return FALSE;
	if(*h>screen->height-*y)
		*h=screen->height-*y;
	if(*h>screen->height-*y)
		return FALSE;

	return TRUE;
}

/*
 * rfbProcessClientNormalMessage is called when the client has sent a normal
 * protocol message.
 */

static void
rfbProcessClientNormalMessage(cl)
    rfbClientPtr cl;
{
    int n=0;
    rfbClientToServerMsg msg;
    char *str;

    if ((n = rfbReadExact(cl, (char *)&msg, 1)) <= 0) {
        if (n != 0)
            rfbLogPerror("rfbProcessClientNormalMessage: read");
        rfbCloseClient(cl);
        return;
    }

    switch (msg.type) {

    case rfbSetPixelFormat:

        if ((n = rfbReadExact(cl, ((char *)&msg) + 1,
                           sz_rfbSetPixelFormatMsg - 1)) <= 0) {
            if (n != 0)
                rfbLogPerror("rfbProcessClientNormalMessage: read");
            rfbCloseClient(cl);
            return;
        }

        cl->format.bitsPerPixel = msg.spf.format.bitsPerPixel;
        cl->format.depth = msg.spf.format.depth;
        cl->format.bigEndian = (msg.spf.format.bigEndian ? TRUE : FALSE);
        cl->format.trueColour = (msg.spf.format.trueColour ? TRUE : FALSE);
        cl->format.redMax = Swap16IfLE(msg.spf.format.redMax);
        cl->format.greenMax = Swap16IfLE(msg.spf.format.greenMax);
        cl->format.blueMax = Swap16IfLE(msg.spf.format.blueMax);
        cl->format.redShift = msg.spf.format.redShift;
        cl->format.greenShift = msg.spf.format.greenShift;
        cl->format.blueShift = msg.spf.format.blueShift;

	cl->readyForSetColourMapEntries = TRUE;
        cl->screen->setTranslateFunction(cl);

        return;


    case rfbFixColourMapEntries:
        if ((n = rfbReadExact(cl, ((char *)&msg) + 1,
                           sz_rfbFixColourMapEntriesMsg - 1)) <= 0) {
            if (n != 0)
                rfbLogPerror("rfbProcessClientNormalMessage: read");
            rfbCloseClient(cl);
            return;
        }
        rfbLog("rfbProcessClientNormalMessage: %s",
                "FixColourMapEntries unsupported\n");
        rfbCloseClient(cl);
        return;


    case rfbSetEncodings:
    {
        int i;
        uint32_t enc;

        if ((n = rfbReadExact(cl, ((char *)&msg) + 1,
                           sz_rfbSetEncodingsMsg - 1)) <= 0) {
            if (n != 0)
                rfbLogPerror("rfbProcessClientNormalMessage: read");
            rfbCloseClient(cl);
            return;
        }

        msg.se.nEncodings = Swap16IfLE(msg.se.nEncodings);

        for (i = 0; i < msg.se.nEncodings; i++) {
            if ((n = rfbReadExact(cl, (char *)&enc, 4)) <= 0) {
                if (n != 0)
                    rfbLogPerror("rfbProcessClientNormalMessage: read");
                rfbCloseClient(cl);
                return;
            }
            enc = Swap32IfLE(enc);

            switch (enc) {

            case rfbEncodingCopyRect:
		cl->useCopyRect = TRUE;
                break;
            case rfbEncodingRaw:
                if (cl->preferredEncoding == -1) {
                    cl->preferredEncoding = enc;
                    rfbLog("Using raw encoding for client %s\n",
                           cl->host);
                }
                break;
            case rfbEncodingRRE:
                if (cl->preferredEncoding == -1) {
                    cl->preferredEncoding = enc;
                    rfbLog("Using rre encoding for client %s\n",
                           cl->host);
                }
                break;
            case rfbEncodingCoRRE:
                if (cl->preferredEncoding == -1) {
                    cl->preferredEncoding = enc;
                    rfbLog("Using CoRRE encoding for client %s\n",
                           cl->host);
                }
                break;
            case rfbEncodingHextile:
                if (cl->preferredEncoding == -1) {
                    cl->preferredEncoding = enc;
                    rfbLog("Using hextile encoding for client %s\n",
                           cl->host);
                }
                break;
#ifdef LIBVNCSERVER_HAVE_LIBZ
	    case rfbEncodingZlib:
		if (cl->preferredEncoding == -1) {
		    cl->preferredEncoding = enc;
		    rfbLog("Using zlib encoding for client %s\n",
			   cl->host);
		}
              break;
#ifdef LIBVNCSERVER_HAVE_LIBJPEG
	    case rfbEncodingTight:
		if (cl->preferredEncoding == -1) {
		    cl->preferredEncoding = enc;
		    rfbLog("Using tight encoding for client %s\n",
			   cl->host);
		}
		break;
#endif
#endif
	    case rfbEncodingXCursor:
		if(!cl->screen->dontConvertRichCursorToXCursor) {
		    rfbLog("Enabling X-style cursor updates for client %s\n",
			   cl->host);
		    /* if cursor was drawn, hide the cursor */
		    if(!cl->enableCursorShapeUpdates)
		        rfbRedrawAfterHideCursor(cl,0);

		    cl->enableCursorShapeUpdates = TRUE;
		    cl->cursorWasChanged = TRUE;
		}
		break;
	    case rfbEncodingRichCursor:
	        rfbLog("Enabling full-color cursor updates for client %s\n",
		       cl->host);
		/* if cursor was drawn, hide the cursor */
		if(!cl->enableCursorShapeUpdates)
		    rfbRedrawAfterHideCursor(cl,0);

	        cl->enableCursorShapeUpdates = TRUE;
	        cl->useRichCursorEncoding = TRUE;
	        cl->cursorWasChanged = TRUE;
	        break;
	    case rfbEncodingPointerPos:
		if (!cl->enableCursorPosUpdates) {
		    rfbLog("Enabling cursor position updates for client %s\n",
			   cl->host);
		    cl->enableCursorPosUpdates = TRUE;
		    cl->cursorWasMoved = TRUE;
		}
	        break;
	    case rfbEncodingLastRect:
		if (!cl->enableLastRectEncoding) {
		    rfbLog("Enabling LastRect protocol extension for client "
			   "%s\n", cl->host);
		    cl->enableLastRectEncoding = TRUE;
		}
		break;
	    case rfbEncodingNewFBSize:
		if (!cl->useNewFBSize) {
		    rfbLog("Enabling NewFBSize protocol extension for client "
			   "%s\n", cl->host);
		    cl->useNewFBSize = TRUE;
		}
		break;
#ifdef LIBVNCSERVER_BACKCHANNEL
	    case rfbEncodingBackChannel:
	        if (!cl->enableBackChannel) {
		    rfbLog("Enabling BackChannel protocol extension for "
			   "client %s\n", cl->host);
		    cl->enableBackChannel = TRUE;
		}
		break;
#endif
#ifdef LIBVNCSERVER_HAVE_LIBZ
           case rfbEncodingZRLE:
               if (cl->preferredEncoding == -1) {
                   cl->preferredEncoding = enc;
                   rfbLog("Using ZRLE encoding for client %s\n",
                          cl->host);
               }
               break;
#endif
            default:
#ifdef LIBVNCSERVER_HAVE_LIBZ
		if ( enc >= (uint32_t)rfbEncodingCompressLevel0 &&
		     enc <= (uint32_t)rfbEncodingCompressLevel9 ) {
		    cl->zlibCompressLevel = enc & 0x0F;
#ifdef LIBVNCSERVER_HAVE_LIBJPEG
		    cl->tightCompressLevel = enc & 0x0F;
		    rfbLog("Using compression level %d for client %s\n",
			   cl->tightCompressLevel, cl->host);
		} else if ( enc >= (uint32_t)rfbEncodingQualityLevel0 &&
			    enc <= (uint32_t)rfbEncodingQualityLevel9 ) {
		    cl->tightQualityLevel = enc & 0x0F;
		    rfbLog("Using image quality level %d for client %s\n",
			   cl->tightQualityLevel, cl->host);
#endif
		} else
#endif
		 rfbLog("rfbProcessClientNormalMessage: ignoring unknown "
                       "encoding type %d\n", (int)enc);
            }
        }

        if (cl->preferredEncoding == -1) {
            cl->preferredEncoding = rfbEncodingRaw;
        }

	if (cl->enableCursorPosUpdates && !cl->enableCursorShapeUpdates) {
	  rfbLog("Disabling cursor position updates for client %s\n",
		 cl->host);
	  cl->enableCursorPosUpdates = FALSE;
	}

        return;
    }


    case rfbFramebufferUpdateRequest:
    {
        sraRegionPtr tmpRegion;

        if ((n = rfbReadExact(cl, ((char *)&msg) + 1,
                           sz_rfbFramebufferUpdateRequestMsg-1)) <= 0) {
            if (n != 0)
                rfbLogPerror("rfbProcessClientNormalMessage: read");
            rfbCloseClient(cl);
            return;
        }

	if(!rectSwapIfLEAndClip(&msg.fur.x,&msg.fur.y,&msg.fur.w,&msg.fur.h,
			cl->screen))
		return;

	tmpRegion =
	  sraRgnCreateRect(msg.fur.x,
			   msg.fur.y,
			   msg.fur.x+msg.fur.w,
			   msg.fur.y+msg.fur.h);

        LOCK(cl->updateMutex);
	sraRgnOr(cl->requestedRegion,tmpRegion);

	if (!cl->readyForSetColourMapEntries) {
	    /* client hasn't sent a SetPixelFormat so is using server's */
	    cl->readyForSetColourMapEntries = TRUE;
	    if (!cl->format.trueColour) {
		if (!rfbSetClientColourMap(cl, 0, 0)) {
		    sraRgnDestroy(tmpRegion);
		    UNLOCK(cl->updateMutex);
		    return;
		}
	    }
	}

       if (!msg.fur.incremental) {
	    sraRgnOr(cl->modifiedRegion,tmpRegion);
	    sraRgnSubtract(cl->copyRegion,tmpRegion);