libvncserver/libvncserver/main.c

/*
 *  This file is called main.c, because it contains most of the new functions
 *  for use with LibVNCServer.
 *
 *  LibVNCServer (C) 2001 Johannes E. Schindelin <Johannes.Schindelin (at) gmx.de>
 *  Original OSXvnc (C) 2001 Dan McGuirk <mcguirk (at) incompleteness.net>.
 *  Original Xvnc (C) 1999 AT&T Laboratories Cambridge.
 *  All Rights Reserved.
 *
 *  see GPL (latest version) for full details
 */

#ifdef __STRICT_ANSI__
#define _BSD_SOURCE
#endif
#include <rfb/rfb.h>
#include <rfb/rfbregion.h>
#include "private.h"

#include <stdarg.h>
#include <errno.h>

#ifndef false
#define false 0
#define true -1
#endif

#ifdef LIBVNCSERVER_HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

#ifndef WIN32
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#endif

#include <signal.h>
#include <time.h>

static int extMutex_initialized = 0;
static int logMutex_initialized = 0;
#ifdef LIBVNCSERVER_HAVE_LIBPTHREAD
static MUTEX(logMutex);
static MUTEX(extMutex);
#endif

static int rfbEnableLogging=1;

#ifdef LIBVNCSERVER_WORDS_BIGENDIAN
char rfbEndianTest = (1==0);
#else
char rfbEndianTest = (1==1);
#endif

/*
 * Protocol extensions
 */

static rfbProtocolExtension* rfbExtensionHead = NULL;

/*
 * This method registers a list of new extensions.
 * It avoids same extension getting registered multiple times.
 * The order is not preserved if multiple extensions are
 * registered at one-go.
 */
void
rfbRegisterProtocolExtension(rfbProtocolExtension* extension)
{
	rfbProtocolExtension *head = rfbExtensionHead, *next = NULL;

	if(extension == NULL)
		return;

	next = extension->next;

	if (! extMutex_initialized) {
		INIT_MUTEX(extMutex);
		extMutex_initialized = 1;
	}

	LOCK(extMutex);

	while(head != NULL) {
		if(head == extension) {
			UNLOCK(extMutex);
			rfbRegisterProtocolExtension(next);
			return;
		}

		head = head->next;
	}

	extension->next = rfbExtensionHead;
	rfbExtensionHead = extension;

	UNLOCK(extMutex);
	rfbRegisterProtocolExtension(next);
}

/*
 * This method unregisters a list of extensions.
 * These extensions won't be available for any new
 * client connection.
 */
void
rfbUnregisterProtocolExtension(rfbProtocolExtension* extension)
{

	rfbProtocolExtension *cur = NULL, *pre = NULL;

	if(extension == NULL)
		return;

	if (! extMutex_initialized) {
		INIT_MUTEX(extMutex);
		extMutex_initialized = 1;
	}

	LOCK(extMutex);

	if(rfbExtensionHead == extension) {
		rfbExtensionHead = rfbExtensionHead->next;
		UNLOCK(extMutex);
		rfbUnregisterProtocolExtension(extension->next);
		return;
	}

	cur = pre = rfbExtensionHead;

	while(cur) {
		if(cur == extension) {
			pre->next = cur->next;
			break;
		}
		pre = cur;
		cur = cur->next;
	}

	UNLOCK(extMutex);

	rfbUnregisterProtocolExtension(extension->next);
}

rfbProtocolExtension* rfbGetExtensionIterator()
{
	if (! extMutex_initialized) {
		INIT_MUTEX(extMutex);
		extMutex_initialized = 1;
	}

	LOCK(extMutex);
	return rfbExtensionHead;
}

void rfbReleaseExtensionIterator()
{
	UNLOCK(extMutex);
}

rfbBool rfbEnableExtension(rfbClientPtr cl, rfbProtocolExtension* extension,
	void* data)
{
	rfbExtensionData* extData;

	/* make sure extension is not yet enabled. */
	for(extData = cl->extensions; extData; extData = extData->next)
		if(extData->extension == extension)
			return FALSE;

	extData = calloc(sizeof(rfbExtensionData),1);
	extData->extension = extension;
	extData->data = data;
	extData->next = cl->extensions;
	cl->extensions = extData;

	return TRUE;
}

rfbBool rfbDisableExtension(rfbClientPtr cl, rfbProtocolExtension* extension)
{
	rfbExtensionData* extData;
	rfbExtensionData* prevData = NULL;

	for(extData = cl->extensions; extData; extData = extData->next) {
		if(extData->extension == extension) {
			if(extData->data)
				free(extData->data);
			if(prevData == NULL)
				cl->extensions = extData->next;
			else
				prevData->next = extData->next;
			return TRUE;
		}
		prevData = extData;
	}

	return FALSE;
}

void* rfbGetExtensionClientData(rfbClientPtr cl, rfbProtocolExtension* extension)
{
    rfbExtensionData* data = cl->extensions;

    while(data && data->extension != extension)
	data = data->next;

    if(data == NULL) {
	rfbLog("Extension is not enabled !\n");
	/* rfbCloseClient(cl); */
	return NULL;
    }

    return data->data;
}

/*
 * Logging
 */

void rfbLogEnable(int enabled) {
  rfbEnableLogging=enabled;
}

/*
 * rfbLog prints a time-stamped message to the log file (stderr).
 */

static void
rfbDefaultLog(const char *format, ...)
{
    va_list args;
    char buf[256];
    time_t log_clock;

    if(!rfbEnableLogging)
      return;

    if (! logMutex_initialized) {
      INIT_MUTEX(logMutex);
      logMutex_initialized = 1;
    }

    LOCK(logMutex);
    va_start(args, format);

    time(&log_clock);
    strftime(buf, 255, "%d/%m/%Y %X ", localtime(&log_clock));
    fprintf(stderr, "%s", buf);

    vfprintf(stderr, format, args);
    fflush(stderr);

    va_end(args);
    UNLOCK(logMutex);
}

rfbLogProc rfbLog=rfbDefaultLog;
rfbLogProc rfbErr=rfbDefaultLog;

void rfbLogPerror(const char *str)
{
    rfbErr("%s: %s\n", str, strerror(errno));
}

void rfbScheduleCopyRegion(rfbScreenInfoPtr rfbScreen,sraRegionPtr copyRegion,int dx,int dy)
{
   rfbClientIteratorPtr iterator;
   rfbClientPtr cl;

   iterator=rfbGetClientIterator(rfbScreen);
   while((cl=rfbClientIteratorNext(iterator))) {
     LOCK(cl->updateMutex);
     if(cl->useCopyRect) {
       sraRegionPtr modifiedRegionBackup;
       if(!sraRgnEmpty(cl->copyRegion)) {
	  if(cl->copyDX!=dx || cl->copyDY!=dy) {
	     /* if a copyRegion was not yet executed, treat it as a
	      * modifiedRegion. The idea: in this case it could be
	      * source of the new copyRect or modified anyway. */
	     sraRgnOr(cl->modifiedRegion,cl->copyRegion);
	     sraRgnMakeEmpty(cl->copyRegion);
	  } else {
	     /* we have to set the intersection of the source of the copy
	      * and the old copy to modified. */
	     modifiedRegionBackup=sraRgnCreateRgn(copyRegion);
	     sraRgnOffset(modifiedRegionBackup,-dx,-dy);
	     sraRgnAnd(modifiedRegionBackup,cl->copyRegion);
	     sraRgnOr(cl->modifiedRegion,modifiedRegionBackup);
	     sraRgnDestroy(modifiedRegionBackup);
	  }
       }

       sraRgnOr(cl->copyRegion,copyRegion);
       cl->copyDX = dx;
       cl->copyDY = dy;

       /* if there were modified regions, which are now copied,
	* mark them as modified, because the source of these can be overlapped
	* either by new modified or now copied regions. */
       modifiedRegionBackup=sraRgnCreateRgn(cl->modifiedRegion);
       sraRgnOffset(modifiedRegionBackup,dx,dy);
       sraRgnAnd(modifiedRegionBackup,cl->copyRegion);
       sraRgnOr(cl->modifiedRegion,modifiedRegionBackup);
       sraRgnDestroy(modifiedRegionBackup);

       if(!cl->enableCursorShapeUpdates) {
          /*
           * n.b. (dx, dy) is the vector pointing in the direction the
           * copyrect displacement will take place.  copyRegion is the
           * destination rectangle (say), not the source rectangle.
           */
          sraRegionPtr cursorRegion;
          int x = cl->cursorX - cl->screen->cursor->xhot;
          int y = cl->cursorY - cl->screen->cursor->yhot;
          int w = cl->screen->cursor->width;
          int h = cl->screen->cursor->height;

          cursorRegion = sraRgnCreateRect(x, y, x + w, y + h);
          sraRgnAnd(cursorRegion, cl->copyRegion);
          if(!sraRgnEmpty(cursorRegion)) {
             /*
              * current cursor rect overlaps with the copy region *dest*,
              * mark it as modified since we won't copy-rect stuff to it.
              */
             sraRgnOr(cl->modifiedRegion, cursorRegion);
          }
          sraRgnDestroy(cursorRegion);

          cursorRegion = sraRgnCreateRect(x, y, x + w, y + h);
          /* displace it to check for overlap with copy region source: */
          sraRgnOffset(cursorRegion, dx, dy);
          sraRgnAnd(cursorRegion, cl->copyRegion);
          if(!sraRgnEmpty(cursorRegion)) {
             /*
              * current cursor rect overlaps with the copy region *source*,
              * mark the *displaced* cursorRegion as modified since we
              * won't copyrect stuff to it.
              */
             sraRgnOr(cl->modifiedRegion, cursorRegion);
          }
          sraRgnDestroy(cursorRegion);
       }

     } else {
       sraRgnOr(cl->modifiedRegion,copyRegion);
     }
     TSIGNAL(cl->updateCond);
     UNLOCK(cl->updateMutex);
   }

   rfbReleaseClientIterator(iterator);
}

void rfbDoCopyRegion(rfbScreenInfoPtr screen,sraRegionPtr copyRegion,int dx,int dy)
{
   sraRectangleIterator* i;
   sraRect rect;
   int j,widthInBytes,bpp=screen->serverFormat.bitsPerPixel/8,
    rowstride=screen->paddedWidthInBytes;
   char *in,*out;

   /* copy it, really */
   i = sraRgnGetReverseIterator(copyRegion,dx<0,dy<0);
   while(sraRgnIteratorNext(i,&rect)) {
     widthInBytes = (rect.x2-rect.x1)*bpp;
     out = screen->frameBuffer+rect.x1*bpp+rect.y1*rowstride;
     in = screen->frameBuffer+(rect.x1-dx)*bpp+(rect.y1-dy)*rowstride;
     if(dy<0)
       for(j=rect.y1;j<rect.y2;j++,out+=rowstride,in+=rowstride)
	 memmove(out,in,widthInBytes);
     else {
       out += rowstride*(rect.y2-rect.y1-1);
       in += rowstride*(rect.y2-rect.y1-1);
       for(j=rect.y2-1;j>=rect.y1;j--,out-=rowstride,in-=rowstride)
	 memmove(out,in,widthInBytes);
     }
   }
   sraRgnReleaseIterator(i);

   rfbScheduleCopyRegion(screen,copyRegion,dx,dy);
}

void rfbDoCopyRect(rfbScreenInfoPtr screen,int x1,int y1,int x2,int y2,int dx,int dy)
{
  sraRegionPtr region = sraRgnCreateRect(x1,y1,x2,y2);
  rfbDoCopyRegion(screen,region,dx,dy);
  sraRgnDestroy(region);
}

void rfbScheduleCopyRect(rfbScreenInfoPtr screen,int x1,int y1,int x2,int y2,int dx,int dy)
{
  sraRegionPtr region = sraRgnCreateRect(x1,y1,x2,y2);
  rfbScheduleCopyRegion(screen,region,dx,dy);
  sraRgnDestroy(region);
}

void rfbMarkRegionAsModified(rfbScreenInfoPtr screen,sraRegionPtr modRegion)
{
   rfbClientIteratorPtr iterator;
   rfbClientPtr cl;

   iterator=rfbGetClientIterator(screen);
   while((cl=rfbClientIteratorNext(iterator))) {
     LOCK(cl->updateMutex);
     sraRgnOr(cl->modifiedRegion,modRegion);
     TSIGNAL(cl->updateCond);
     UNLOCK(cl->updateMutex);
   }

   rfbReleaseClientIterator(iterator);
}

void rfbScaledScreenUpdate(rfbScreenInfoPtr screen, int x1, int y1, int x2, int y2);
void rfbMarkRectAsModified(rfbScreenInfoPtr screen,int x1,int y1,int x2,int y2)
{
   sraRegionPtr region;
   int i;

   if(x1>x2) { i=x1; x1=x2; x2=i; }
   if(x1<0) x1=0;
   if(x2>screen->width) x2=screen->width;
   if(x1==x2) return;

   if(y1>y2) { i=y1; y1=y2; y2=i; }
   if(y1<0) y1=0;
   if(y2>screen->height) y2=screen->height;
   if(y1==y2) return;

   /* update scaled copies for this rectangle */
   rfbScaledScreenUpdate(screen,x1,y1,x2,y2);

   region = sraRgnCreateRect(x1,y1,x2,y2);
   rfbMarkRegionAsModified(screen,region);
   sraRgnDestroy(region);
}

#ifdef LIBVNCSERVER_HAVE_LIBPTHREAD
#include <unistd.h>

static void *
clientOutput(void *data)
{
    rfbClientPtr cl = (rfbClientPtr)data;
    rfbBool haveUpdate;
    sraRegion* updateRegion;

    while (1) {
        haveUpdate = false;
        while (!haveUpdate) {
		if (cl->sock == -1) {
			/* Client has disconnected. */
			return NULL;
		}
		if (cl->state != RFB_NORMAL || cl->onHold) {
			/* just sleep until things get normal */
			usleep(cl->screen->deferUpdateTime * 1000);
			continue;
		}

		LOCK(cl->updateMutex);

		if (sraRgnEmpty(cl->requestedRegion)) {
			; /* always require a FB Update Request (otherwise can crash.) */
		} else {
			haveUpdate = FB_UPDATE_PENDING(cl);
			if(!haveUpdate) {
				updateRegion = sraRgnCreateRgn(cl->modifiedRegion);
				haveUpdate   = sraRgnAnd(updateRegion,cl->requestedRegion);
				sraRgnDestroy(updateRegion);
			}
		}

		if (!haveUpdate) {
			WAIT(cl->updateCond, cl->updateMutex);
		}

		UNLOCK(cl->updateMutex);
        }

        /* OK, now, to save bandwidth, wait a little while for more
           updates to come along. */
        usleep(cl->screen->deferUpdateTime * 1000);

        /* Now, get the region we're going to update, and remove
           it from cl->modifiedRegion _before_ we send the update.
           That way, if anything that overlaps the region we're sending
           is updated, we'll be sure to do another update later. */
        LOCK(cl->updateMutex);
	updateRegion = sraRgnCreateRgn(cl->modifiedRegion);
        UNLOCK(cl->updateMutex);

        /* Now actually send the update. */
	rfbIncrClientRef(cl);
        LOCK(cl->sendMutex);
        rfbSendFramebufferUpdate(cl, updateRegion);
        UNLOCK(cl->sendMutex);
	rfbDecrClientRef(cl);

	sraRgnDestroy(updateRegion);
    }

    /* Not reached. */
    return NULL;
}

static void *
clientInput(void *data)
{
    rfbClientPtr cl = (rfbClientPtr)data;
    pthread_t output_thread;
    pthread_create(&output_thread, NULL, clientOutput, (void *)cl);

    while (1) {
	fd_set rfds, wfds, efds;
	struct timeval tv;
	int n;

	if (cl->sock == -1) {
	  /* Client has disconnected. */
            break;
        }

	FD_ZERO(&rfds);
	FD_SET(cl->sock, &rfds);
	FD_ZERO(&efds);
	FD_SET(cl->sock, &efds);

	/* Are we transferring a file in the background? */
	FD_ZERO(&wfds);
	if ((cl->fileTransfer.fd!=-1) && (cl->fileTransfer.sending==1))
	    FD_SET(cl->sock, &wfds);

	tv.tv_sec = 60; /* 1 minute */
	tv.tv_usec = 0;
	n = select(cl->sock + 1, &rfds, &wfds, &efds, &tv);
	if (n < 0) {
	    rfbLogPerror("ReadExact: select");
	    break;
	}
	if (n == 0) /* timeout */
	{
            rfbSendFileTransferChunk(cl);
	    continue;
        }

        /* We have some space on the transmit queue, send some data */
        if (FD_ISSET(cl->sock, &wfds))
            rfbSendFileTransferChunk(cl);

        if (FD_ISSET(cl->sock, &rfds) || FD_ISSET(cl->sock, &efds))
            rfbProcessClientMessage(cl);
    }

    /* Get rid of the output thread. */
    LOCK(cl->updateMutex);
    TSIGNAL(cl->updateCond);
    UNLOCK(cl->updateMutex);
    IF_PTHREADS(pthread_join(output_thread, NULL));

    rfbClientConnectionGone(cl);

    return NULL;
}

static void*
listenerRun(void *data)
{
    rfbScreenInfoPtr screen=(rfbScreenInfoPtr)data;
    int client_fd;
    struct sockaddr_storage peer;
    rfbClientPtr cl = NULL;
    socklen_t len;
    fd_set listen_fds;  /* temp file descriptor list for select() */

    /* TODO: this thread wont die by restarting the server */
    /* TODO: HTTP is not handled */
    while (1) {
        client_fd = -1;
        FD_ZERO(&listen_fds);
	if(screen->listenSock >= 0)
	  FD_SET(screen->listenSock, &listen_fds);
	if(screen->listen6Sock >= 0)
	  FD_SET(screen->listen6Sock, &listen_fds);

        if (select(screen->maxFd+1, &listen_fds, NULL, NULL, NULL) == -1) {
            rfbLogPerror("listenerRun: error in select");
            return NULL;
        }

	/* there is something on the listening sockets, handle new connections */
	len = sizeof (peer);
	if (FD_ISSET(screen->listenSock, &listen_fds))
	    client_fd = accept(screen->listenSock, (struct sockaddr*)&peer, &len);
	else if (FD_ISSET(screen->listen6Sock, &listen_fds))
	    client_fd = accept(screen->listen6Sock, (struct sockaddr*)&peer, &len);

	if(client_fd >= 0)
	  cl = rfbNewClient(screen,client_fd);
	if (cl && !cl->onHold )
	  rfbStartOnHoldClient(cl);
    }
    return(NULL);
}

void
rfbStartOnHoldClient(rfbClientPtr cl)
{
    pthread_create(&cl->client_thread, NULL, clientInput, (void *)cl);
}

#else

void
rfbStartOnHoldClient(rfbClientPtr cl)
{
	cl->onHold = FALSE;
}

#endif

void
rfbRefuseOnHoldClient(rfbClientPtr cl)
{
    rfbCloseClient(cl);
    rfbClientConnectionGone(cl);
}

static void
rfbDefaultKbdAddEvent(rfbBool down, rfbKeySym keySym, rfbClientPtr cl)
{
}

void
rfbDefaultPtrAddEvent(int buttonMask, int x, int y, rfbClientPtr cl)
{
  rfbClientIteratorPtr iterator;
  rfbClientPtr other_client;
  rfbScreenInfoPtr s = cl->screen;

  if (x != s->cursorX || y != s->cursorY) {
    LOCK(s->cursorMutex);
    s->cursorX = x;
    s->cursorY = y;
    UNLOCK(s->cursorMutex);

    /* The cursor was moved by this client, so don't send CursorPos. */
    if (cl->enableCursorPosUpdates)
      cl->cursorWasMoved = FALSE;

    /* But inform all remaining clients about this cursor movement. */
    iterator = rfbGetClientIterator(s);
    while ((other_client = rfbClientIteratorNext(iterator)) != NULL) {
      if (other_client != cl && other_client->enableCursorPosUpdates) {
	other_client->cursorWasMoved = TRUE;
      }
    }
    rfbReleaseClientIterator(iterator);
  }
}

static void rfbDefaultSetXCutText(char* text, int len, rfbClientPtr cl)
{
}

/* TODO: add a nice VNC or RFB cursor */

#if defined(WIN32) || defined(sparc) || !defined(NO_STRICT_ANSI)
static rfbCursor myCursor =
{
   FALSE, FALSE, FALSE, FALSE,
   (unsigned char*)"\000\102\044\030\044\102\000",
   (unsigned char*)"\347\347\176\074\176\347\347",
   8, 7, 3, 3,
   0, 0, 0,
   0xffff, 0xffff, 0xffff,
   NULL
};
#else
static rfbCursor myCursor =
{
   cleanup: FALSE,
   cleanupSource: FALSE,
   cleanupMask: FALSE,
   cleanupRichSource: FALSE,
   source: "\000\102\044\030\044\102\000",
   mask:   "\347\347\176\074\176\347\347",
   width: 8, height: 7, xhot: 3, yhot: 3,
   foreRed: 0, foreGreen: 0, foreBlue: 0,
   backRed: 0xffff, backGreen: 0xffff, backBlue: 0xffff,
   richSource: NULL
};
#endif

static rfbCursorPtr rfbDefaultGetCursorPtr(rfbClientPtr cl)
{
   return(cl->screen->cursor);
}

/* response is cl->authChallenge vncEncrypted with passwd */
static rfbBool rfbDefaultPasswordCheck(rfbClientPtr cl,const char* response,int len)
{
  int i;
  char *passwd=rfbDecryptPasswdFromFile(cl->screen->authPasswdData);

  if(!passwd) {
    rfbErr("Couldn't read password file: %s\n",cl->screen->authPasswdData);
    return(FALSE);
  }

  rfbEncryptBytes(cl->authChallenge, passwd);

  /* Lose the password from memory */
  for (i = strlen(passwd); i >= 0; i--) {
    passwd[i] = '\0';
  }

  free(passwd);

  if (memcmp(cl->authChallenge, response, len) != 0) {
    rfbErr("authProcessClientMessage: authentication failed from %s\n",
	   cl->host);
    return(FALSE);
  }

  return(TRUE);
}

/* for this method, authPasswdData is really a pointer to an array
   of char*'s, where the last pointer is 0. */
rfbBool rfbCheckPasswordByList(rfbClientPtr cl,const char* response,int len)
{
  char **passwds;
  int i=0;

  for(passwds=(char**)cl->screen->authPasswdData;*passwds;passwds++,i++) {
    uint8_t auth_tmp[CHALLENGESIZE];
    memcpy((char *)auth_tmp, (char *)cl->authChallenge, CHALLENGESIZE);
    rfbEncryptBytes(auth_tmp, *passwds);

    if (memcmp(auth_tmp, response, len) == 0) {
      if(i>=cl->screen->authPasswdFirstViewOnly)
	cl->viewOnly=TRUE;
      return(TRUE);
    }
  }

  rfbErr("authProcessClientMessage: authentication failed from %s\n",
	 cl->host);
  return(FALSE);
}

void rfbDoNothingWithClient(rfbClientPtr cl)
{
}

static enum rfbNewClientAction rfbDefaultNewClientHook(rfbClientPtr cl)
{
	return RFB_CLIENT_ACCEPT;
}

/*
 * Update server's pixel format in screenInfo structure. This
 * function is called from rfbGetScreen() and rfbNewFramebuffer().
 */

static void rfbInitServerFormat(rfbScreenInfoPtr screen, int bitsPerSample)
{
   rfbPixelFormat* format=&screen->serverFormat;

   format->bitsPerPixel = screen->bitsPerPixel;
   format->depth = screen->depth;
   format->bigEndian = rfbEndianTest?FALSE:TRUE;
   format->trueColour = TRUE;
   screen->colourMap.count = 0;
   screen->colourMap.is16 = 0;
   screen->colourMap.data.bytes = NULL;

   if (format->bitsPerPixel == 8) {
     format->redMax = 7;
     format->greenMax = 7;
     format->blueMax = 3;
     format->redShift = 0;
     format->greenShift = 3;
     format->blueShift = 6;
   } else {
     format->redMax = (1 << bitsPerSample) - 1;
     format->greenMax = (1 << bitsPerSample) - 1;
     format->blueMax = (1 << bitsPerSample) - 1;
     if(rfbEndianTest) {
       format->redShift = 0;
       format->greenShift = bitsPerSample;
       format->blueShift = bitsPerSample * 2;
     } else {
       if(format->bitsPerPixel==8*3) {
	 format->redShift = bitsPerSample*2;
	 format->greenShift = bitsPerSample*1;
	 format->blueShift = 0;
       } else {
	 format->redShift = bitsPerSample*3;
	 format->greenShift = bitsPerSample*2;
	 format->blueShift = bitsPerSample;
       }
     }
   }
}

rfbScreenInfoPtr rfbGetScreen(int* argc,char** argv,
 int width,int height,int bitsPerSample,int samplesPerPixel,
 int bytesPerPixel)
{
   rfbScreenInfoPtr screen=calloc(sizeof(rfbScreenInfo),1);

   if (! logMutex_initialized) {
     INIT_MUTEX(logMutex);
     logMutex_initialized = 1;
   }


   if(width&3)
     rfbErr("WARNING: Width (%d) is not a multiple of 4. VncViewer has problems with that.\n",width);

   screen->autoPort=FALSE;
   screen->clientHead=NULL;
   screen->pointerClient=NULL;
   screen->port=5900;
   screen->ipv6port=5900;
   screen->socketState=RFB_SOCKET_INIT;

   screen->inetdInitDone = FALSE;
   screen->inetdSock=-1;

   screen->udpSock=-1;
   screen->udpSockConnected=FALSE;
   screen->udpPort=0;
   screen->udpClient=NULL;

   screen->maxFd=0;
   screen->listenSock=-1;
   screen->listen6Sock=-1;

   screen->httpInitDone=FALSE;
   screen->httpEnableProxyConnect=FALSE;
   screen->httpPort=0;
   screen->http6Port=0;
   screen->httpDir=NULL;
   screen->httpListenSock=-1;
   screen->httpListen6Sock=-1;
   screen->httpSock=-1;

   screen->desktopName = "LibVNCServer";
   screen->alwaysShared = FALSE;
   screen->neverShared = FALSE;
   screen->dontDisconnect = FALSE;
   screen->authPasswdData = NULL;
   screen->authPasswdFirstViewOnly = 1;

   screen->width = width;
   screen->height = height;
   screen->bitsPerPixel = screen->depth = 8*bytesPerPixel;

   screen->passwordCheck = rfbDefaultPasswordCheck;

   screen->ignoreSIGPIPE = TRUE;

   /* disable progressive updating per default */
   screen->progressiveSliceHeight = 0;

   screen->listenInterface = htonl(INADDR_ANY);

   screen->deferUpdateTime=5;
   screen->maxRectsPerUpdate=50;

   screen->handleEventsEagerly = FALSE;

   screen->protocolMajorVersion = rfbProtocolMajorVersion;
   screen->protocolMinorVersion = rfbProtocolMinorVersion;

   screen->permitFileTransfer = FALSE;

   if(!rfbProcessArguments(screen,argc,argv)) {
     free(screen);
     return NULL;
   }

#ifdef WIN32
   {
	   DWORD dummy=255;
	   GetComputerName(screen->thisHost,&dummy);
   }
#else
   gethostname(screen->thisHost, 255);
#endif

   screen->paddedWidthInBytes = width*bytesPerPixel;

   /* format */

   rfbInitServerFormat(screen, bitsPerSample);

   /* cursor */

   screen->cursorX=screen->cursorY=screen->underCursorBufferLen=0;
   screen->underCursorBuffer=NULL;
   screen->dontConvertRichCursorToXCursor = FALSE;
   screen->cursor = &myCursor;
   INIT_MUTEX(screen->cursorMutex);

   IF_PTHREADS(screen->backgroundLoop = FALSE);

   /* proc's and hook's */

   screen->kbdAddEvent = rfbDefaultKbdAddEvent;
   screen->kbdReleaseAllKeys = rfbDoNothingWithClient;
   screen->ptrAddEvent = rfbDefaultPtrAddEvent;
   screen->setXCutText = rfbDefaultSetXCutText;
   screen->getCursorPtr = rfbDefaultGetCursorPtr;
   screen->setTranslateFunction = rfbSetTranslateFunction;
   screen->newClientHook = rfbDefaultNewClientHook;
   screen->displayHook = NULL;
   screen->displayFinishedHook = NULL;
   screen->getKeyboardLedStateHook = NULL;
   screen->xvpHook = NULL;

   /* initialize client list and iterator mutex */
   rfbClientListInit(screen);

   return(screen);
}

/*
 * Switch to another framebuffer (maybe of different size and color
 * format). Clients supporting NewFBSize pseudo-encoding will change
 * their local framebuffer dimensions if necessary.
 * NOTE: Rich cursor data should be converted to new pixel format by
 * the caller.
 */

void rfbNewFramebuffer(rfbScreenInfoPtr screen, char *framebuffer,
                       int width, int height,
                       int bitsPerSample, int samplesPerPixel,
                       int bytesPerPixel)
{
  rfbPixelFormat old_format;
  rfbBool format_changed = FALSE;
  rfbClientIteratorPtr iterator;
  rfbClientPtr cl;

  /* Update information in the screenInfo structure */

  old_format = screen->serverFormat;

  if (width & 3)
    rfbErr("WARNING: New width (%d) is not a multiple of 4.\n", width);

  screen->width = width;
  screen->height = height;
  screen->bitsPerPixel = screen->depth = 8*bytesPerPixel;
  screen->paddedWidthInBytes = width*bytesPerPixel;

  rfbInitServerFormat(screen, bitsPerSample);

  if (memcmp(&screen->serverFormat, &old_format,
             sizeof(rfbPixelFormat)) != 0) {
    format_changed = TRUE;
  }

  screen->frameBuffer = framebuffer;

  /* Adjust pointer position if necessary */

  if (screen->cursorX >= width)
    screen->cursorX = width - 1;
  if (screen->cursorY >= height)
    screen->cursorY = height - 1;

  /* For each client: */
  iterator = rfbGetClientIterator(screen);
  while ((cl = rfbClientIteratorNext(iterator)) != NULL) {

    /* Re-install color translation tables if necessary */

    if (format_changed)
      screen->setTranslateFunction(cl);

    /* Mark the screen contents as changed, and schedule sending
       NewFBSize message if supported by this client. */

    LOCK(cl->updateMutex);
    sraRgnDestroy(cl->modifiedRegion);
    cl->modifiedRegion = sraRgnCreateRect(0, 0, width, height);
    sraRgnMakeEmpty(cl->copyRegion);
    cl->copyDX = 0;
    cl->copyDY = 0;

    if (cl->useNewFBSize)
      cl->newFBSizePending = TRUE;

    TSIGNAL(cl->updateCond);
    UNLOCK(cl->updateMutex);
  }
  rfbReleaseClientIterator(iterator);
}

/* hang up on all clients and free all reserved memory */

void rfbScreenCleanup(rfbScreenInfoPtr screen)
{
  rfbClientIteratorPtr i=rfbGetClientIterator(screen);
  rfbClientPtr cl,cl1=rfbClientIteratorNext(i);
  while(cl1) {
    cl=rfbClientIteratorNext(i);
    rfbClientConnectionGone(cl1);
    cl1=cl;
  }
  rfbReleaseClientIterator(i);

#define FREE_IF(x) if(screen->x) free(screen->x)
  FREE_IF(colourMap.data.bytes);
  FREE_IF(underCursorBuffer);
  TINI_MUTEX(screen->cursorMutex);
  if(screen->cursor && screen->cursor->cleanup)
    rfbFreeCursor(screen->cursor);

#ifdef LIBVNCSERVER_HAVE_LIBZ
  rfbZlibCleanup(screen);
#ifdef LIBVNCSERVER_HAVE_LIBJPEG
  rfbTightCleanup(screen);
#endif

  /* free all 'scaled' versions of this screen */
  while (screen->scaledScreenNext!=NULL)
  {
      rfbScreenInfoPtr ptr;
      ptr = screen->scaledScreenNext;
      screen->scaledScreenNext = ptr->scaledScreenNext;
      free(ptr->frameBuffer);
      free(ptr);
  }

#endif
  free(screen);
}

void rfbInitServer(rfbScreenInfoPtr screen)
{
#ifdef WIN32
  WSADATA trash;
  WSAStartup(MAKEWORD(2,2),&trash);
#endif
  rfbInitSockets(screen);
  rfbHttpInitSockets(screen);
#ifndef WIN32
  if(screen->ignoreSIGPIPE)
    signal(SIGPIPE,SIG_IGN);
#endif
}

void rfbShutdownServer(rfbScreenInfoPtr screen,rfbBool disconnectClients) {
  if(disconnectClients) {
    rfbClientPtr cl;
    rfbClientIteratorPtr iter = rfbGetClientIterator(screen);
    while( (cl = rfbClientIteratorNext(iter)) ) {
      if (cl->sock > -1) {
       /* we don't care about maxfd here, because the server goes away */
       rfbCloseClient(cl);
       rfbClientConnectionGone(cl);
      }
    }
    rfbReleaseClientIterator(iter);
  }

  rfbShutdownSockets(screen);
  rfbHttpShutdownSockets(screen);
}

#ifndef LIBVNCSERVER_HAVE_GETTIMEOFDAY
#include <fcntl.h>
#include <conio.h>
#include <sys/timeb.h>

void gettimeofday(struct timeval* tv,char* dummy)
{
   SYSTEMTIME t;
   GetSystemTime(&t);
   tv->tv_sec=t.wHour*3600+t.wMinute*60+t.wSecond;
   tv->tv_usec=t.wMilliseconds*1000;
}
#endif

rfbBool
rfbProcessEvents(rfbScreenInfoPtr screen,long usec)
{
  rfbClientIteratorPtr i;
  rfbClientPtr cl,clPrev;
  rfbBool result=FALSE;
  extern rfbClientIteratorPtr
    rfbGetClientIteratorWithClosed(rfbScreenInfoPtr rfbScreen);

  if(usec<0)
    usec=screen->deferUpdateTime*1000;

  rfbCheckFds(screen,usec);
  rfbHttpCheckFds(screen);

  i = rfbGetClientIteratorWithClosed(screen);
  cl=rfbClientIteratorHead(i);
  while(cl) {
    result = rfbUpdateClient(cl);
    clPrev=cl;
    cl=rfbClientIteratorNext(i);
    if(clPrev->sock==-1) {
      rfbClientConnectionGone(clPrev);
      result=TRUE;
    }
  }
  rfbReleaseClientIterator(i);

  return result;
}

rfbBool
rfbUpdateClient(rfbClientPtr cl)
{
  struct timeval tv;
  rfbBool result=FALSE;
  rfbScreenInfoPtr screen = cl->screen;

  if (cl->sock >= 0 && !cl->onHold && FB_UPDATE_PENDING(cl) &&
        !sraRgnEmpty(cl->requestedRegion)) {
      result=TRUE;
      if(screen->deferUpdateTime == 0) {
          rfbSendFramebufferUpdate(cl,cl->modifiedRegion);
      } else if(cl->startDeferring.tv_usec == 0) {
        gettimeofday(&cl->startDeferring,NULL);
        if(cl->startDeferring.tv_usec == 0)
          cl->startDeferring.tv_usec++;
      } else {
        gettimeofday(&tv,NULL);
        if(tv.tv_sec < cl->startDeferring.tv_sec /* at midnight */
           || ((tv.tv_sec-cl->startDeferring.tv_sec)*1000
               +(tv.tv_usec-cl->startDeferring.tv_usec)/1000)
             > screen->deferUpdateTime) {
          cl->startDeferring.tv_usec = 0;
          rfbSendFramebufferUpdate(cl,cl->modifiedRegion);
        }
      }
    }

    if (!cl->viewOnly && cl->lastPtrX >= 0) {
      if(cl->startPtrDeferring.tv_usec == 0) {
        gettimeofday(&cl->startPtrDeferring,NULL);
        if(cl->startPtrDeferring.tv_usec == 0)
          cl->startPtrDeferring.tv_usec++;
      } else {
        struct timeval tv;
        gettimeofday(&tv,NULL);
        if(tv.tv_sec < cl->startPtrDeferring.tv_sec /* at midnight */
           || ((tv.tv_sec-cl->startPtrDeferring.tv_sec)*1000
           +(tv.tv_usec-cl->startPtrDeferring.tv_usec)/1000)
           > cl->screen->deferPtrUpdateTime) {
          cl->startPtrDeferring.tv_usec = 0;
          cl->screen->ptrAddEvent(cl->lastPtrButtons,
                                  cl->lastPtrX,
                                  cl->lastPtrY, cl);
          cl->lastPtrX = -1;
        }
      }
    }

    return result;
}

rfbBool rfbIsActive(rfbScreenInfoPtr screenInfo) {
  return screenInfo->socketState!=RFB_SOCKET_SHUTDOWN || screenInfo->clientHead!=NULL;
}

void rfbRunEventLoop(rfbScreenInfoPtr screen, long usec, rfbBool runInBackground)
{
  if(runInBackground) {
#ifdef LIBVNCSERVER_HAVE_LIBPTHREAD
       pthread_t listener_thread;

       screen->backgroundLoop = TRUE;

       pthread_create(&listener_thread, NULL, listenerRun, screen);
    return;
#else
    rfbErr("Can't run in background, because I don't have PThreads!\n");
    return;
#endif
  }

  if(usec<0)
    usec=screen->deferUpdateTime*1000;

  while(rfbIsActive(screen))
    rfbProcessEvents(screen,usec);
}