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Added : ZSTD decompression : ability to resist to noisy/faulty data source

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This commit is contained in:
Yann Collet
2015-08-23 23:13:49 +01:00
parent cf5ce55cca
commit d5d9bc3f82
7 changed files with 68 additions and 68 deletions
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4
programs/Makefile
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@ -73,10 +73,10 @@ fullbench : $(ZSTDDIR)/zstd.c datagen.c fullbench.c
fullbench32: $(ZSTDDIR)/zstd.c datagen.c fullbench.c
$(CC) -m32 $(FLAGS) $^ -o $@$(EXT)
fuzzer : $(ZSTDDIR)/zstd.c xxhash.c fuzzer.c
fuzzer : $(ZSTDDIR)/zstd.c datagen.c xxhash.c fuzzer.c
$(CC) $(FLAGS) $^ -o $@$(EXT)
fuzzer32: $(ZSTDDIR)/zstd.c xxhash.c fuzzer.c
fuzzer32: $(ZSTDDIR)/zstd.c datagen.c xxhash.c fuzzer.c
$(CC) -m32 $(FLAGS) $^ -o $@$(EXT)
datagen : datagen.c datagencli.c

4
programs/datagen.c
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@ -153,7 +153,7 @@ void RDG_genBlock(void* buffer, size_t buffSize, size_t prefixSize, double match
memset(buffPtr+pos, 0, size0);
pos += size0;
buffPtr[pos-1] = RDG_genChar(seed, lt);
return;
continue;
}
/* init */
@ -200,7 +200,7 @@ void RDG_genBuffer(void* buffer, size_t size, double matchProba, double litProba
#define RDG_DICTSIZE (32 KB)
#define RDG_BLOCKSIZE (128 KB)
void RDG_genOut(unsigned long long size, double matchProba, double litProba, unsigned seed)
void RDG_genStdout(unsigned long long size, double matchProba, double litProba, unsigned seed)
{
BYTE* buff = (BYTE*)malloc(RDG_DICTSIZE + RDG_BLOCKSIZE);
U64 total = 0;

12
programs/datagen.h
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@ -26,15 +26,15 @@
#include <stddef.h> /* size_t */
void RDG_genOut(unsigned long long size, double matchProba, double litProba, unsigned seed);
void RDG_genStdout(unsigned long long size, double matchProba, double litProba, unsigned seed);
void RDG_genBuffer(void* buffer, size_t size, double matchProba, double litProba, unsigned seed);
/* RDG_genBuffer
Generate 'size' bytes of compressible data into 'buffer'.
Compressibility can be controlled using 'matchProba'.
'LitProba' is optional, and affect variability of individual bytes. If litProba==0.0, default value is used.
Compressibility can be controlled using 'matchProba', which is floating point value between 0 and 1.
'LitProba' is optional, it affect variability of individual bytes. If litProba==0.0, default value will be used.
Generated data pattern can be modified using different 'seed'.
If (matchProba, litProba and seed) are equal, the function always generate the same content.
For a triplet (matchProba, litProba, seed), the function always generate the same content.
RDG_genOut
Same as RDG_genBuffer, but generate data towards stdout
RDG_genStdout
Same as RDG_genBuffer, but generates data into stdout
*/

2
programs/datagencli.c
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@ -183,7 +183,7 @@ int main(int argc, char** argv)
DISPLAYLEVEL(3, "Seed = %u \n", seed);
if (proba!=COMPRESSIBILITY_DEFAULT) DISPLAYLEVEL(3, "Compressibility : %i%%\n", (U32)(proba*100));
RDG_genOut(size, proba, litProba, seed);
RDG_genStdout(size, proba, litProba, seed);
DISPLAYLEVEL(1, "\n");
return 0;

101
programs/fuzzer.c
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@ -47,6 +47,7 @@
#include <sys/timeb.h> /* timeb */
#include <string.h> /* strcmp */
#include "zstd_static.h"
#include "datagen.h" /* RDG_genBuffer */
#include "xxhash.h" /* XXH64 */
@ -138,45 +139,6 @@ unsigned int FUZ_rand(unsigned int* src)
}
#define FUZ_RAND15BITS (FUZ_rand(seed) & 0x7FFF)
#define FUZ_RANDLENGTH ( (FUZ_rand(seed) & 3) ? (FUZ_rand(seed) % 15) : (FUZ_rand(seed) % 510) + 15)
static void FUZ_generateSynthetic(void* buffer, size_t bufferSize, double proba, U32* seed)
{
BYTE* BBuffer = (BYTE*)buffer;
unsigned pos = 0;
U32 P32 = (U32)(32768 * proba);
// First Byte
BBuffer[pos++] = (BYTE)((FUZ_rand(seed) & 0x3F) + '0');
while (pos < bufferSize)
{
// Select : Literal (noise) or copy (within 64K)
if (FUZ_RAND15BITS < P32)
{
// Copy (within 64K)
size_t match, end;
size_t length = FUZ_RANDLENGTH + 4;
size_t offset = FUZ_RAND15BITS + 1;
if (offset > pos) offset = pos;
if (pos + length > bufferSize) length = bufferSize - pos;
match = pos - offset;
end = pos + length;
while (pos < end) BBuffer[pos++] = BBuffer[match++];
}
else
{
// Literal (noise)
size_t end;
size_t length = FUZ_RANDLENGTH;
if (pos + length > bufferSize) length = bufferSize - pos;
end = pos + length;
while (pos < end) BBuffer[pos++] = (BYTE)((FUZ_rand(seed) & 0x3F) + '0');
}
}
}
static unsigned FUZ_highbit32(U32 v32)
{
unsigned nbBits = 0;
@ -200,7 +162,7 @@ static int basicUnitTests(U32 seed, double compressibility)
size_t result, cSize;
U32 testNb=0;
// Create compressible test buffer
/* Create compressible test buffer */
CNBuffer = malloc(COMPRESSIBLE_NOISE_LENGTH);
compressedBuffer = malloc(ZSTD_compressBound(COMPRESSIBLE_NOISE_LENGTH));
decodedBuffer = malloc(COMPRESSIBLE_NOISE_LENGTH);
@ -210,9 +172,9 @@ static int basicUnitTests(U32 seed, double compressibility)
testResult = 1;
goto _end;
}
FUZ_generateSynthetic(CNBuffer, COMPRESSIBLE_NOISE_LENGTH, compressibility, &randState);
RDG_genBuffer(CNBuffer, COMPRESSIBLE_NOISE_LENGTH, compressibility, 0., randState);
// Basic tests
/* Basic tests */
DISPLAYLEVEL(4, "test%3i : compress %u bytes : ", testNb++, COMPRESSIBLE_NOISE_LENGTH);
result = ZSTD_compress(compressedBuffer, ZSTD_compressBound(COMPRESSIBLE_NOISE_LENGTH), CNBuffer, COMPRESSIBLE_NOISE_LENGTH);
if (ZSTD_isError(result)) goto _output_error;
@ -263,10 +225,10 @@ static int basicUnitTests(U32 seed, double compressibility)
{
size_t sampleSize = 0;
DISPLAYLEVEL(4, "test%3i : Long RLE test : ", testNb++);
FUZ_generateSynthetic(CNBuffer, sampleSize, compressibility, &randState);
RDG_genBuffer(CNBuffer, sampleSize, compressibility, 0., randState);
memset((char*)CNBuffer+sampleSize, 'B', 256 KB - 1);
sampleSize += 256 KB - 1;
FUZ_generateSynthetic((char*)CNBuffer+sampleSize, 96 KB, compressibility, &randState);
RDG_genBuffer((char*)CNBuffer+sampleSize, 96 KB, compressibility, 0., randState);
sampleSize += 96 KB;
cSize = ZSTD_compress(compressedBuffer, ZSTD_compressBound(sampleSize), CNBuffer, sampleSize);
if (ZSTD_isError(cSize)) goto _output_error;
@ -311,6 +273,7 @@ static const U32 maxSampleLog = 22;
int fuzzerTests(U32 seed, U32 nbTests, unsigned startTest, double compressibility)
{
BYTE* cNoiseBuffer[5];
BYTE* srcBuffer;
BYTE* cBuffer;
BYTE* dstBuffer;
@ -322,13 +285,23 @@ int fuzzerTests(U32 seed, U32 nbTests, unsigned startTest, double compressibilit
U32 coreSeed = seed, lseed = 0;
/* allocation */
srcBuffer = (BYTE*)malloc (srcBufferSize);
cNoiseBuffer[0] = (BYTE*)malloc (srcBufferSize);
cNoiseBuffer[1] = (BYTE*)malloc (srcBufferSize);
cNoiseBuffer[2] = (BYTE*)malloc (srcBufferSize);
cNoiseBuffer[3] = (BYTE*)malloc (srcBufferSize);
cNoiseBuffer[4] = (BYTE*)malloc (srcBufferSize);
dstBuffer = (BYTE*)malloc (dstBufferSize);
cBuffer = (BYTE*)malloc (cBufferSize);
CHECK (!srcBuffer || !dstBuffer || !cBuffer, "Not enough memory, fuzzer tests cancelled");
CHECK (!cNoiseBuffer[0] || !cNoiseBuffer[1] || !cNoiseBuffer[2] || !dstBuffer || !cBuffer,
"Not enough memory, fuzzer tests cancelled");
/* Create initial sample */
FUZ_generateSynthetic(srcBuffer, srcBufferSize, compressibility, &coreSeed);
/* Create initial samples */
RDG_genBuffer(cNoiseBuffer[0], srcBufferSize, 0.00, 0., coreSeed); /* pure noise */
RDG_genBuffer(cNoiseBuffer[1], srcBufferSize, 0.05, 0., coreSeed); /* barely compressible */
RDG_genBuffer(cNoiseBuffer[2], srcBufferSize, compressibility, 0., coreSeed);
RDG_genBuffer(cNoiseBuffer[3], srcBufferSize, 0.95, 0., coreSeed); /* highly compressible */
RDG_genBuffer(cNoiseBuffer[4], srcBufferSize, 1.00, 0., coreSeed); /* sparse content */
srcBuffer = cNoiseBuffer[2];
/* catch up testNb */
for (testNb=1; testNb < startTest; testNb++)
@ -339,13 +312,30 @@ int fuzzerTests(U32 seed, U32 nbTests, unsigned startTest, double compressibilit
{
size_t sampleSize, sampleStart;
size_t cSize, dSize, dSupSize;
U32 sampleSizeLog;
U32 sampleSizeLog, buffNb;
U64 crcOrig, crcDest;
/* init */
DISPLAYUPDATE(2, "\r%6u/%6u ", testNb, nbTests);
FUZ_rand(&coreSeed);
lseed = coreSeed ^ prime1;
buffNb = FUZ_rand(&lseed) & 127;
if (buffNb & 7) buffNb=2;
else
{
buffNb >>= 3;
if (buffNb & 7)
{
const U32 tnb[2] = { 1, 3 };
buffNb = tnb[buffNb >> 3];
}
else
{
const U32 tnb[2] = { 0, 4 };
buffNb = tnb[buffNb >> 3];
}
}
srcBuffer = cNoiseBuffer[buffNb];
sampleSizeLog = FUZ_rand(&lseed) % maxSampleLog;
sampleSize = (size_t)1 << sampleSizeLog;
sampleSize += FUZ_rand(&lseed) & (sampleSize-1);
@ -357,7 +347,7 @@ int fuzzerTests(U32 seed, U32 nbTests, unsigned startTest, double compressibilit
CHECK(ZSTD_isError(cSize), "ZSTD_compress failed");
/* compression failure test : too small dest buffer */
if (cSize > 3)
if (cSize > 3)
{
size_t errorCode;
const size_t missing = (FUZ_rand(&lseed) % (cSize-2)) + 1; /* no problem, as cSize > 4 (frameHeaderSizer) */
@ -384,8 +374,8 @@ int fuzzerTests(U32 seed, U32 nbTests, unsigned startTest, double compressibilit
const size_t missing = (FUZ_rand(&lseed) % (cSize-2)) + 1; /* no problem, as cSize > 4 (frameHeaderSizer) */
const size_t tooSmallSize = cSize - missing;
void* cBufferTooSmall = malloc(tooSmallSize); /* valgrind will catch overflows */
memcpy(cBufferTooSmall, cBuffer, tooSmallSize);
CHECK(cBufferTooSmall == NULL, "not enough memory !");
memcpy(cBufferTooSmall, cBuffer, tooSmallSize);
errorCode = ZSTD_decompress(dstBuffer, dstBufferSize, cBufferTooSmall, tooSmallSize);
CHECK(!ZSTD_isError(errorCode), "ZSTD_decompress should have failed ! (truncated src buffer)");
free(cBufferTooSmall);
@ -422,6 +412,7 @@ int fuzzerTests(U32 seed, U32 nbTests, unsigned startTest, double compressibilit
if (nbBits>0) nbBits--;
mask = (1<<nbBits) - 1;
noiseLength = (FUZ_rand(&lseed) & mask) + 1;
if ( pos+noiseLength > cSize ) noiseLength = cSize-pos;
noiseStart = FUZ_rand(&lseed) % (srcBufferSize - noiseLength);
memcpy(cBuffer + pos, srcBuffer + noiseStart, noiseLength);
pos += noiseLength;
@ -435,9 +426,11 @@ int fuzzerTests(U32 seed, U32 nbTests, unsigned startTest, double compressibilit
/* decompress noisy source */
{
U32 noiseSrc = FUZ_rand(&lseed) % 5;
const U32 endMark = 0xA9B1C3D6;
U32 endCheck;
size_t errorCode;
srcBuffer = cNoiseBuffer[noiseSrc];
memcpy(dstBuffer+sampleSize, &endMark, 4);
errorCode = ZSTD_decompress(dstBuffer, sampleSize, cBuffer, cSize);
/* result *may* be an unlikely success, but even then, it must strictly respect dest buffer boundaries */
@ -451,7 +444,11 @@ int fuzzerTests(U32 seed, U32 nbTests, unsigned startTest, double compressibilit
DISPLAY("\rAll fuzzer tests completed \n");
_cleanup:
free(srcBuffer);
free(cNoiseBuffer[0]);
free(cNoiseBuffer[1]);
free(cNoiseBuffer[2]);
free(cNoiseBuffer[3]);
free(cNoiseBuffer[4]);
free(cBuffer);
free(dstBuffer);
return result;