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KasmVNC/common/rfb/PixelFormat.cxx
Pierre Ossman ed73ac2aa7 Handle pixel formats with odd shift values 
Our fast paths assume that each channel fits in to a separate byte.
That means the shift needs to be a multiple of 8. Start actually
checking this so that a client cannot trip us up and possibly cause
incorrect code exection.

Issue found by Pavel Cheremushkin from Kaspersky Lab.
2020-09-21 12:56:53 +03:00

745 lines
18 KiB
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/* Copyright (C) 2002-2005 RealVNC Ltd. All Rights Reserved.
* Copyright (C) 2011 D. R. Commander. 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 <assert.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <rdr/InStream.h>
#include <rdr/OutStream.h>
#include <rfb/Exception.h>
#include <rfb/PixelFormat.h>
#include <rfb/util.h>
#ifdef _WIN32
#define strcasecmp _stricmp
#endif
using namespace rfb;
rdr::U8 PixelFormat::upconvTable[256*8];
rdr::U8 PixelFormat::downconvTable[256*8];
class PixelFormat::Init {
public:
Init();
};
PixelFormat::Init PixelFormat::_init;
PixelFormat::Init::Init()
{
int bits;
// Shifting bits is almost perfect, but not quite. And
// a lookup table is still quicker when there is a large
// difference between the source and destination depth.
for (bits = 1;bits <= 8;bits++) {
int i, maxVal;
rdr::U8 *subUpTable;
rdr::U8 *subDownTable;
maxVal = (1 << bits) - 1;
subUpTable = &upconvTable[(bits-1)*256];
subDownTable = &downconvTable[(bits-1)*256];
for (i = 0;i <= maxVal;i++)
subUpTable[i] = i * 255 / maxVal;
// Duplicate the up table so that we don't have to care about
// the upper bits when doing a lookup
for (;i < 256;i += maxVal+1)
memcpy(&subUpTable[i], &subUpTable[0], maxVal+1);
for (i = 0;i <= 255;i++)
subDownTable[i] = (i * maxVal + 128) / 255;
}
}
PixelFormat::PixelFormat(int b, int d, bool e, bool t,
int rm, int gm, int bm, int rs, int gs, int bs)
: bpp(b), depth(d), trueColour(t), bigEndian(e),
redMax(rm), greenMax(gm), blueMax(bm),
redShift(rs), greenShift(gs), blueShift(bs)
{
assert(isSane());
updateState();
}
PixelFormat::PixelFormat()
: bpp(8), depth(8), trueColour(true), bigEndian(false),
redMax(7), greenMax(7), blueMax(3),
redShift(0), greenShift(3), blueShift(6)
{
updateState();
}
bool PixelFormat::equal(const PixelFormat& other) const
{
if (bpp != other.bpp || depth != other.depth)
return false;
if (redMax != other.redMax)
return false;
if (greenMax != other.greenMax)
return false;
if (blueMax != other.blueMax)
return false;
// Endianness requires more care to determine compatibility
if (bigEndian == other.bigEndian || bpp == 8) {
if (redShift != other.redShift)
return false;
if (greenShift != other.greenShift)
return false;
if (blueShift != other.blueShift)
return false;
} else {
// Has to be the same byte for each channel
if (redShift/8 != (3 - other.redShift/8))
return false;
if (greenShift/8 != (3 - other.greenShift/8))
return false;
if (blueShift/8 != (3 - other.blueShift/8))
return false;
// And the same bit offset within the byte
if (redShift%8 != other.redShift%8)
return false;
if (greenShift%8 != other.greenShift%8)
return false;
if (blueShift%8 != other.blueShift%8)
return false;
// And not cross a byte boundary
if (redShift/8 != (redShift + redBits - 1)/8)
return false;
if (greenShift/8 != (greenShift + greenBits - 1)/8)
return false;
if (blueShift/8 != (blueShift + blueBits - 1)/8)
return false;
}
return true;
}
void PixelFormat::read(rdr::InStream* is)
{
bpp = is->readU8();
depth = is->readU8();
bigEndian = is->readU8();
trueColour = is->readU8();
redMax = is->readU16();
greenMax = is->readU16();
blueMax = is->readU16();
redShift = is->readU8();
greenShift = is->readU8();
blueShift = is->readU8();
is->skip(3);
// We have no real support for colour maps. If the client
// wants one, then we force a 8-bit true colour format and
// pretend it's a colour map.
if (!trueColour) {
redMax = 7;
greenMax = 7;
blueMax = 3;
redShift = 0;
greenShift = 3;
blueShift = 6;
}
if (!isSane())
throw Exception("invalid pixel format");
updateState();
}
void PixelFormat::write(rdr::OutStream* os) const
{
os->writeU8(bpp);
os->writeU8(depth);
os->writeU8(bigEndian);
os->writeU8(trueColour);
os->writeU16(redMax);
os->writeU16(greenMax);
os->writeU16(blueMax);
os->writeU8(redShift);
os->writeU8(greenShift);
os->writeU8(blueShift);
os->pad(3);
}
bool PixelFormat::is888(void) const
{
if (!trueColour)
return false;
if (bpp != 32)
return false;
if (depth != 24)
return false;
if (redMax != 255)
return false;
if (greenMax != 255)
return false;
if (blueMax != 255)
return false;
if ((redShift & 0x7) != 0)
return false;
if ((greenShift & 0x7) != 0)
return false;
if ((blueShift & 0x7) != 0)
return false;
return true;
}
bool PixelFormat::isBigEndian(void) const
{
return bigEndian;
}
bool PixelFormat::isLittleEndian(void) const
{
return ! bigEndian;
}
void PixelFormat::bufferFromRGB(rdr::U8 *dst, const rdr::U8* src, int pixels) const
{
bufferFromRGB(dst, src, pixels, pixels, 1);
}
void PixelFormat::bufferFromRGB(rdr::U8 *dst, const rdr::U8* src,
int w, int stride, int h) const
{
if (is888()) {
// Optimised common case
rdr::U8 *r, *g, *b, *x;
if (bigEndian) {
r = dst + (24 - redShift)/8;
g = dst + (24 - greenShift)/8;
b = dst + (24 - blueShift)/8;
x = dst + (24 - (48 - redShift - greenShift - blueShift))/8;
} else {
r = dst + redShift/8;
g = dst + greenShift/8;
b = dst + blueShift/8;
x = dst + (48 - redShift - greenShift - blueShift)/8;
}
int dstPad = (stride - w) * 4;
while (h--) {
int w_ = w;
while (w_--) {
*r = *(src++);
*g = *(src++);
*b = *(src++);
*x = 0;
r += 4;
g += 4;
b += 4;
x += 4;
}
r += dstPad;
g += dstPad;
b += dstPad;
x += dstPad;
}
} else {
// Generic code
int dstPad = (stride - w) * bpp/8;
while (h--) {
int w_ = w;
while (w_--) {
Pixel p;
rdr::U8 r, g, b;
r = *(src++);
g = *(src++);
b = *(src++);
p = pixelFromRGB(r, g, b);
bufferFromPixel(dst, p);
dst += bpp/8;
}
dst += dstPad;
}
}
}
void PixelFormat::rgbFromBuffer(rdr::U8* dst, const rdr::U8* src, int pixels) const
{
rgbFromBuffer(dst, src, pixels, pixels, 1);
}
void PixelFormat::rgbFromBuffer(rdr::U8* dst, const rdr::U8* src,
int w, int stride, int h) const
{
if (is888()) {
// Optimised common case
const rdr::U8 *r, *g, *b;
if (bigEndian) {
r = src + (24 - redShift)/8;
g = src + (24 - greenShift)/8;
b = src + (24 - blueShift)/8;
} else {
r = src + redShift/8;
g = src + greenShift/8;
b = src + blueShift/8;
}
int srcPad = (stride - w) * 4;
while (h--) {
int w_ = w;
while (w_--) {
*(dst++) = *r;
*(dst++) = *g;
*(dst++) = *b;
r += 4;
g += 4;
b += 4;
}
r += srcPad;
g += srcPad;
b += srcPad;
}
} else {
// Generic code
int srcPad = (stride - w) * bpp/8;
while (h--) {
int w_ = w;
while (w_--) {
Pixel p;
rdr::U8 r, g, b;
p = pixelFromBuffer(src);
rgbFromPixel(p, &r, &g, &b);
*(dst++) = r;
*(dst++) = g;
*(dst++) = b;
src += bpp/8;
}
src += srcPad;
}
}
}
Pixel PixelFormat::pixelFromPixel(const PixelFormat &srcPF, Pixel src) const
{
rdr::U16 r, g, b;
srcPF.rgbFromPixel(src, &r, &g, &b);
return pixelFromRGB(r, g, b);
}
void PixelFormat::bufferFromBuffer(rdr::U8* dst, const PixelFormat &srcPF,
const rdr::U8* src, int pixels) const
{
bufferFromBuffer(dst, srcPF, src, pixels, 1, pixels, pixels);
}
#define IS_ALIGNED(v, a) (((intptr_t)v & (a-1)) == 0)
void PixelFormat::bufferFromBuffer(rdr::U8* dst, const PixelFormat &srcPF,
const rdr::U8* src, int w, int h,
int dstStride, int srcStride) const
{
if (equal(srcPF)) {
// Trivial case
while (h--) {
memcpy(dst, src, w * bpp/8);
dst += dstStride * bpp/8;
src += srcStride * srcPF.bpp/8;
}
} else if (is888() && srcPF.is888()) {
// Optimised common case A: byte shuffling (e.g. endian conversion)
rdr::U8 *d[4], *s[4];
int dstPad, srcPad;
if (bigEndian) {
s[0] = dst + (24 - redShift)/8;
s[1] = dst + (24 - greenShift)/8;
s[2] = dst + (24 - blueShift)/8;
s[3] = dst + (24 - (48 - redShift - greenShift - blueShift))/8;
} else {
s[0] = dst + redShift/8;
s[1] = dst + greenShift/8;
s[2] = dst + blueShift/8;
s[3] = dst + (48 - redShift - greenShift - blueShift)/8;
}
if (srcPF.bigEndian) {
d[(24 - srcPF.redShift)/8] = s[0];
d[(24 - srcPF.greenShift)/8] = s[1];
d[(24 - srcPF.blueShift)/8] = s[2];
d[(24 - (48 - srcPF.redShift - srcPF.greenShift - srcPF.blueShift))/8] = s[3];
} else {
d[srcPF.redShift/8] = s[0];
d[srcPF.greenShift/8] = s[1];
d[srcPF.blueShift/8] = s[2];
d[(48 - srcPF.redShift - srcPF.greenShift - srcPF.blueShift)/8] = s[3];
}
dstPad = (dstStride - w) * 4;
srcPad = (srcStride - w) * 4;
while (h--) {
int w_ = w;
while (w_--) {
*d[0] = *(src++);
*d[1] = *(src++);
*d[2] = *(src++);
*d[3] = *(src++);
d[0] += 4;
d[1] += 4;
d[2] += 4;
d[3] += 4;
}
d[0] += dstPad;
d[1] += dstPad;
d[2] += dstPad;
d[3] += dstPad;
src += srcPad;
}
} else if (IS_ALIGNED(dst, bpp/8) && srcPF.is888()) {
// Optimised common case B: 888 source
switch (bpp) {
case 8:
directBufferFromBufferFrom888((rdr::U8*)dst, srcPF, src,
w, h, dstStride, srcStride);
break;
case 16:
directBufferFromBufferFrom888((rdr::U16*)dst, srcPF, src,
w, h, dstStride, srcStride);
break;
case 32:
directBufferFromBufferFrom888((rdr::U32*)dst, srcPF, src,
w, h, dstStride, srcStride);
break;
}
} else if (IS_ALIGNED(src, srcPF.bpp/8) && is888()) {
// Optimised common case C: 888 destination
switch (srcPF.bpp) {
case 8:
directBufferFromBufferTo888(dst, srcPF, (rdr::U8*)src,
w, h, dstStride, srcStride);
break;
case 16:
directBufferFromBufferTo888(dst, srcPF, (rdr::U16*)src,
w, h, dstStride, srcStride);
break;
case 32:
directBufferFromBufferTo888(dst, srcPF, (rdr::U32*)src,
w, h, dstStride, srcStride);
break;
}
} else {
// Generic code
int dstPad = (dstStride - w) * bpp/8;
int srcPad = (srcStride - w) * srcPF.bpp/8;
while (h--) {
int w_ = w;
while (w_--) {
Pixel p;
rdr::U8 r, g, b;
p = srcPF.pixelFromBuffer(src);
srcPF.rgbFromPixel(p, &r, &g, &b);
p = pixelFromRGB(r, g, b);
bufferFromPixel(dst, p);
dst += bpp/8;
src += srcPF.bpp/8;
}
dst += dstPad;
src += srcPad;
}
}
}
void PixelFormat::print(char* str, int len) const
{
// Unfortunately snprintf is not widely available so we build the string up
// using strncat - not pretty, but should be safe against buffer overruns.
char num[20];
if (len < 1) return;
str[0] = 0;
strncat(str, "depth ", len-1-strlen(str));
sprintf(num,"%d",depth);
strncat(str, num, len-1-strlen(str));
strncat(str, " (", len-1-strlen(str));
sprintf(num,"%d",bpp);
strncat(str, num, len-1-strlen(str));
strncat(str, "bpp)", len-1-strlen(str));
if (bpp != 8) {
if (bigEndian)
strncat(str, " big-endian", len-1-strlen(str));
else
strncat(str, " little-endian", len-1-strlen(str));
}
if (!trueColour) {
strncat(str, " color-map", len-1-strlen(str));
return;
}
if (blueShift == 0 && greenShift > blueShift && redShift > greenShift &&
blueMax == (1 << greenShift) - 1 &&
greenMax == (1 << (redShift-greenShift)) - 1 &&
redMax == (1 << (depth-redShift)) - 1)
{
strncat(str, " rgb", len-1-strlen(str));
sprintf(num,"%d",depth-redShift);
strncat(str, num, len-1-strlen(str));
sprintf(num,"%d",redShift-greenShift);
strncat(str, num, len-1-strlen(str));
sprintf(num,"%d",greenShift);
strncat(str, num, len-1-strlen(str));
return;
}
if (redShift == 0 && greenShift > redShift && blueShift > greenShift &&
redMax == (1 << greenShift) - 1 &&
greenMax == (1 << (blueShift-greenShift)) - 1 &&
blueMax == (1 << (depth-blueShift)) - 1)
{
strncat(str, " bgr", len-1-strlen(str));
sprintf(num,"%d",depth-blueShift);
strncat(str, num, len-1-strlen(str));
sprintf(num,"%d",blueShift-greenShift);
strncat(str, num, len-1-strlen(str));
sprintf(num,"%d",greenShift);
strncat(str, num, len-1-strlen(str));
return;
}
strncat(str, " rgb max ", len-1-strlen(str));
sprintf(num,"%d,",redMax);
strncat(str, num, len-1-strlen(str));
sprintf(num,"%d,",greenMax);
strncat(str, num, len-1-strlen(str));
sprintf(num,"%d",blueMax);
strncat(str, num, len-1-strlen(str));
strncat(str, " shift ", len-1-strlen(str));
sprintf(num,"%d,",redShift);
strncat(str, num, len-1-strlen(str));
sprintf(num,"%d,",greenShift);
strncat(str, num, len-1-strlen(str));
sprintf(num,"%d",blueShift);
strncat(str, num, len-1-strlen(str));
}
bool PixelFormat::parse(const char* str)
{
char rgbbgr[4];
int bits1, bits2, bits3;
if (sscanf(str, "%3s%1d%1d%1d", rgbbgr, &bits1, &bits2, &bits3) < 4)
return false;
depth = bits1 + bits2 + bits3;
bpp = depth <= 8 ? 8 : ((depth <= 16) ? 16 : 32);
trueColour = true;
rdr::U32 endianTest = 1;
bigEndian = (*(rdr::U8*)&endianTest == 0);
greenShift = bits3;
greenMax = (1 << bits2) - 1;
if (strcasecmp(rgbbgr, "bgr") == 0) {
redShift = 0;
redMax = (1 << bits3) - 1;
blueShift = bits3 + bits2;
blueMax = (1 << bits1) - 1;
} else if (strcasecmp(rgbbgr, "rgb") == 0) {
blueShift = 0;
blueMax = (1 << bits3) - 1;
redShift = bits3 + bits2;
redMax = (1 << bits1) - 1;
} else {
return false;
}
assert(isSane());
updateState();
return true;
}
static int bits(rdr::U16 value)
{
int bits;
bits = 16;
if (!(value & 0xff00)) {
bits -= 8;
value <<= 8;
}
if (!(value & 0xf000)) {
bits -= 4;
value <<= 4;
}
if (!(value & 0xc000)) {
bits -= 2;
value <<= 2;
}
if (!(value & 0x8000)) {
bits -= 1;
value <<= 1;
}
return bits;
}
void PixelFormat::updateState(void)
{
int endianTest = 1;
redBits = bits(redMax);
greenBits = bits(greenMax);
blueBits = bits(blueMax);
maxBits = redBits;
if (greenBits > maxBits)
maxBits = greenBits;
if (blueBits > maxBits)
maxBits = blueBits;
minBits = redBits;
if (greenBits < minBits)
minBits = greenBits;
if (blueBits < minBits)
minBits = blueBits;
if (((*(char*)&endianTest) == 0) != bigEndian)
endianMismatch = true;
else
endianMismatch = false;
}
bool PixelFormat::isSane(void)
{
int totalBits;
if ((bpp != 8) && (bpp != 16) && (bpp != 32))
return false;
if (depth > bpp)
return false;
if (!trueColour && (depth != 8))
return false;
if ((redMax & (redMax + 1)) != 0)
return false;
if ((greenMax & (greenMax + 1)) != 0)
return false;
if ((blueMax & (blueMax + 1)) != 0)
return false;
/*
* We don't allow individual channels > 8 bits in order to keep our
* conversions simple.
*/
if (redMax >= (1 << 8))
return false;
if (greenMax >= (1 << 8))
return false;
if (blueMax >= (1 << 8))
return false;
totalBits = bits(redMax) + bits(greenMax) + bits(blueMax);
if (totalBits > depth)
return false;
if ((bits(redMax) + redShift) > bpp)
return false;
if ((bits(greenMax) + greenShift) > bpp)
return false;
if ((bits(blueMax) + blueShift) > bpp)
return false;
if (((redMax << redShift) & (greenMax << greenShift)) != 0)
return false;
if (((redMax << redShift) & (blueMax << blueShift)) != 0)
return false;
if (((greenMax << greenShift) & (blueMax << blueShift)) != 0)
return false;
return true;
}
// Preprocessor generated, optimised methods
#define INBPP 8
#define OUTBPP 8
#include "PixelFormatBPP.cxx"
#undef OUTBPP
#define OUTBPP 16
#include "PixelFormatBPP.cxx"
#undef OUTBPP
#define OUTBPP 32
#include "PixelFormatBPP.cxx"
#undef OUTBPP
#undef INBPP
#define INBPP 16
#define OUTBPP 8
#include "PixelFormatBPP.cxx"
#undef OUTBPP
#define OUTBPP 16
#include "PixelFormatBPP.cxx"
#undef OUTBPP
#define OUTBPP 32
#include "PixelFormatBPP.cxx"
#undef OUTBPP
#undef INBPP
#define INBPP 32
#define OUTBPP 8
#include "PixelFormatBPP.cxx"
#undef OUTBPP
#define OUTBPP 16
#include "PixelFormatBPP.cxx"
#undef OUTBPP
#define OUTBPP 32
#include "PixelFormatBPP.cxx"
#undef OUTBPP
#undef INBPP
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