metasploit-framework/external/source/vncdll/winvnc/vncEncodeRRE.cpp

348 lines
11 KiB
C++

// Copyright (C) 2000 Tridia Corporation. All Rights Reserved.
// Copyright (C) 1999 AT&T Laboratories Cambridge. All Rights Reserved.
//
// This file is part of the VNC system.
//
// The VNC system 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 program 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 program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
//
// TightVNC distribution homepage on the Web: http://www.tightvnc.com/
//
// If the source code for the VNC system is not available from the place
// whence you received this file, check http://www.uk.research.att.com/vnc or contact
// the authors on vnc@uk.research.att.com for information on obtaining it.
// vncEncodeRRE
// This file implements the vncEncoder-derived vncEncodeRRE class.
// This class overrides some vncEncoder functions to produce a bitmap
// to RRE encoder. RRE is much more efficient than RAW format on
// most screen data.
#include "vncEncodeRRE.h"
vncEncodeRRE::vncEncodeRRE()
{
m_buffer = NULL;
m_bufflen = 0;
}
vncEncodeRRE::~vncEncodeRRE()
{
if (m_buffer != NULL)
{
delete [] m_buffer;
m_buffer = NULL;
}
}
void
vncEncodeRRE::Init()
{
vncEncoder::Init();
}
UINT
vncEncodeRRE::RequiredBuffSize(UINT width, UINT height)
{
return vncEncoder::RequiredBuffSize(width, height);
}
UINT
vncEncodeRRE::NumCodedRects(RECT &rect)
{
return 1;
}
/*****************************************************************************
*
* Routines to implement Rise-and-Run-length Encoding (RRE). This code is
* based on krw's original javatel rfbserver.
* This code courtesy of tjr
*/
/*
* rreBeforeBuf contains pixel data in the client's format.
* rreAfterBuf contains the RRE encoded version. If the RRE encoded version is
* larger than the raw data or if it exceeds rreAfterBufSize then
* normal encoding is used instead.
*/
static int rreAfterBufLen;
static int subrectEncode8 (CARD8 *data, CARD8 *buf, int w, int h, int maxBytes);
static int subrectEncode16 (CARD16 *data, CARD8 *buf, int w, int h, int maxBytes);
static int subrectEncode32 (CARD32 *data, CARD8 *buf, int w, int h, int maxBytes);
static CARD32 getBgColour (char *data, int size, int bpp);
/*
* subrectEncode() encodes the given multicoloured rectangle as a background
* colour overwritten by single-coloured rectangles. It returns the number
* of subrectangles in the encoded buffer, or -1 if subrect encoding won't
* fit in the buffer. It puts the encoded rectangles in rreAfterBuf. The
* single-colour rectangle partition is not optimal, but does find the biggest
* horizontal or vertical rectangle top-left anchored to each consecutive
* coordinate position.
*
* The coding scheme is simply [<bgcolour><subrect><subrect>...] where each
* <subrect> is [<colour><x><y><w><h>].
*
* This code has been modified from tjr's original by Wez(jnw)
*/
#define DEFINE_SUBRECT_ENCODE(bpp) \
static int \
subrectEncode##bpp( \
CARD##bpp *data, \
CARD8 *buf, \
int w, \
int h, \
int maxBytes \
) \
{ \
CARD##bpp cl; \
rfbRectangle subrect; \
int x,y; \
int i,j; \
int hx,hy,vx,vy; \
int hyflag; \
CARD##bpp *seg; \
CARD##bpp *line; \
int hw,hh,vw,vh; \
int thex,they,thew,theh; \
int numsubs = 0; \
int newLen; \
CARD##bpp bg = (CARD##bpp)getBgColour((char*)data,w*h,bpp); \
\
/* Set the background colour value */ \
*((CARD##bpp *)buf) = bg; \
\
rreAfterBufLen = (bpp/8); \
\
for (y=0; y<h; y++) { \
line = data+(y*w); \
for (x=0; x<w; x++) { \
if (line[x] != bg) { \
cl = line[x]; \
hy = y-1; \
hyflag = 1; \
for (j=y; j<h; j++) { \
seg = data+(j*w); \
if (seg[x] != cl) {break;} \
i = x; \
while ((i < w) && (seg[i] == cl)) i += 1; \
i -= 1; \
if (j == y) vx = hx = i; \
if (i < vx) vx = i; \
if ((hyflag > 0) && (i >= hx)) {hy += 1;} else {hyflag = 0;} \
} \
vy = j-1; \
\
/* We now have two possible subrects: (x,y,hx,hy) and (x,y,vx,vy) \
* We'll choose the bigger of the two. \
*/ \
hw = hx-x+1; \
hh = hy-y+1; \
vw = vx-x+1; \
vh = vy-y+1; \
\
thex = x; \
they = y; \
\
if ((hw*hh) > (vw*vh)) { \
thew = hw; \
theh = hh; \
} else { \
thew = vw; \
theh = vh; \
} \
\
subrect.x = Swap16IfLE(thex); \
subrect.y = Swap16IfLE(they); \
subrect.w = Swap16IfLE(thew); \
subrect.h = Swap16IfLE(theh); \
\
newLen = rreAfterBufLen + (bpp/8) + sz_rfbRectangle; \
if ((newLen > (w * h * (bpp/8))) || (newLen > maxBytes)) \
return -1; \
\
numsubs += 1; \
*((CARD##bpp *)(buf + rreAfterBufLen)) = cl; \
rreAfterBufLen += (bpp/8); \
memcpy(&buf[rreAfterBufLen],&subrect, sz_rfbRectangle); \
rreAfterBufLen += sz_rfbRectangle; \
\
/* \
* Now mark the subrect as done. \
*/ \
for (j=they; j < (they+theh); j++) { \
for (i=thex; i < (thex+thew); i++) { \
data[j*w+i] = bg; \
} \
} \
} \
} \
} \
\
return numsubs; \
}
DEFINE_SUBRECT_ENCODE(8)
DEFINE_SUBRECT_ENCODE(16)
DEFINE_SUBRECT_ENCODE(32)
/*
* getBgColour() gets the most prevalent colour in a byte array.
*/
static CARD32
getBgColour(char *data, int size, int bpp)
{
#define NUMCLRS 256
static int counts[NUMCLRS];
int i,j,k;
int maxcount = 0;
CARD8 maxclr = 0;
if (bpp != 8) {
if (bpp == 16) {
return ((CARD16 *)data)[0];
} else if (bpp == 32) {
return ((CARD32 *)data)[0];
} else {
fprintf(stderr,"getBgColour: bpp %d?\n",bpp);
exit(1);
}
}
for (i=0; i<NUMCLRS; i++) {
counts[i] = 0;
}
for (j=0; j<size; j++) {
k = (int)(((CARD8 *)data)[j]);
if (k >= NUMCLRS) {
fprintf(stderr, "%s: unusual colour = %d\n", "getBgColour",k);
exit(1);
}
counts[k] += 1;
if (counts[k] > maxcount) {
maxcount = counts[k];
maxclr = ((CARD8 *)data)[j];
}
}
return maxclr;
}
// Encode the rectangle using RRE
inline UINT
vncEncodeRRE::EncodeRect(BYTE *source, BYTE *dest, const RECT &rect, int offx, int offy)
{
int subrects = -1;
const UINT rectW = rect.right - rect.left;
const UINT rectH = rect.bottom - rect.top;
// Create the rectangle header
rfbFramebufferUpdateRectHeader *surh=(rfbFramebufferUpdateRectHeader *)dest;
surh->r.x = (CARD16) rect.left;
surh->r.y = (CARD16) rect.top;
surh->r.w = (CARD16) (rectW);
surh->r.h = (CARD16) (rectH);
surh->r.x = Swap16IfLE(surh->r.x - offx);
surh->r.y = Swap16IfLE(surh->r.y - offy);
surh->r.w = Swap16IfLE(surh->r.w);
surh->r.h = Swap16IfLE(surh->r.h);
surh->encoding = Swap32IfLE(rfbEncodingRRE);
// create a space big enough for the RRE encoded pixels
size_t rectSize = rectW * rectH * (m_remoteformat.bitsPerPixel / 8);
if (m_bufflen < rectSize)
{
if (m_buffer != NULL)
{
delete [] m_buffer;
m_buffer = NULL;
}
m_buffer = new BYTE [rectSize + 1];
if (m_buffer == NULL)
return vncEncoder::EncodeRect(source, dest, rect, offx, offy);
m_bufflen = rectSize;
}
// Translate the data into our new buffer
Translate(source, m_buffer, rect);
// Choose the appropriate encoding routine (for speed...)
switch(m_remoteformat.bitsPerPixel)
{
case 8:
subrects = subrectEncode8(
m_buffer,
dest+sz_rfbFramebufferUpdateRectHeader+sz_rfbRREHeader,
rectW,
rectH,
(int)(m_bufflen-sz_rfbFramebufferUpdateRectHeader-sz_rfbRREHeader)
);
break;
case 16:
subrects = subrectEncode16(
(CARD16 *)m_buffer,
(CARD8 *)(dest+sz_rfbFramebufferUpdateRectHeader+sz_rfbRREHeader),
rectW,
rectH,
(int)(m_bufflen-sz_rfbFramebufferUpdateRectHeader-sz_rfbRREHeader)
);
break;
case 32:
subrects = subrectEncode32(
(CARD32 *)m_buffer,
(CARD8 *)(dest+sz_rfbFramebufferUpdateRectHeader+sz_rfbRREHeader),
rectW,
rectH,
(int)(m_bufflen-sz_rfbFramebufferUpdateRectHeader-sz_rfbRREHeader)
);
break;
}
// If we couldn't encode the rectangles then just send the data raw
if (subrects < 0)
return vncEncoder::EncodeRect(source, dest, rect, offx, offy);
// Send the RREHeader
rfbRREHeader *rreh=(rfbRREHeader *)(dest+sz_rfbFramebufferUpdateRectHeader);
rreh->nSubrects = Swap32IfLE(subrects);
// Update statistics for this rectangle.
rectangleOverhead += sz_rfbFramebufferUpdateRectHeader;
dataSize += ( rectW * rectH * m_remoteformat.bitsPerPixel) / 8;
encodedSize += sz_rfbRREHeader +
(m_remoteformat.bitsPerPixel / 8) +
(subrects * (sz_rfbRectangle + m_remoteformat.bitsPerPixel / 8));
transmittedSize += sz_rfbFramebufferUpdateRectHeader +
sz_rfbRREHeader +
(m_remoteformat.bitsPerPixel / 8) +
(subrects * (sz_rfbRectangle + m_remoteformat.bitsPerPixel / 8));
// Return the amount of data sent
return sz_rfbFramebufferUpdateRectHeader + sz_rfbRREHeader +
(m_remoteformat.bitsPerPixel / 8) +
(subrects * (sz_rfbRectangle + m_remoteformat.bitsPerPixel / 8));
}