| b3840d2f |
#include "7zCrc.h"
#include "CpuArch.h"
#include "Xz.h"
SRes Xz_ReadHeader(CXzStreamFlags *p, ISeqInStream *inStream)
{
Byte sig[XZ_STREAM_HEADER_SIZE];
RINOK(SeqInStream_Read2(inStream, sig, XZ_STREAM_HEADER_SIZE, SZ_ERROR_NO_ARCHIVE));
if (memcmp(sig, XZ_SIG, XZ_SIG_SIZE) != 0)
return SZ_ERROR_NO_ARCHIVE;
return Xz_ParseHeader(p, sig);
}
#define READ_VARINT_AND_CHECK(buf, pos, size, res) \
{ unsigned s = Xz_ReadVarInt(buf + pos, size - pos, res); \
if (s == 0) return SZ_ERROR_ARCHIVE; pos += s; }
SRes XzBlock_ReadHeader(CXzBlock *p, ISeqInStream *inStream, Bool *isIndex, UInt32 *headerSizeRes)
{
Byte header[XZ_BLOCK_HEADER_SIZE_MAX];
unsigned headerSize;
*headerSizeRes = 0;
RINOK(SeqInStream_ReadByte(inStream, &header[0]));
headerSize = ((unsigned)header[0] << 2) + 4;
if (headerSize == 0)
{
*headerSizeRes = 1;
*isIndex = True;
return SZ_OK;
}
*isIndex = False;
*headerSizeRes = headerSize;
RINOK(SeqInStream_Read(inStream, header + 1, headerSize - 1));
return XzBlock_Parse(p, header);
}
#define ADD_SIZE_CHECH(size, val) \
{ UInt64 newSize = size + (val); if (newSize < size) return XZ_SIZE_OVERFLOW; size = newSize; }
UInt64 Xz_GetUnpackSize(const CXzStream *p)
{
UInt64 size = 0;
size_t i;
for (i = 0; i < p->numBlocks; i++)
ADD_SIZE_CHECH(size, p->blocks[i].unpackSize);
return size;
}
UInt64 Xz_GetPackSize(const CXzStream *p)
{
UInt64 size = 0;
size_t i;
for (i = 0; i < p->numBlocks; i++)
ADD_SIZE_CHECH(size, (p->blocks[i].totalSize + 3) & ~(UInt64)3);
return size;
}
/*
SRes XzBlock_ReadFooter(CXzBlock *p, CXzStreamFlags f, ISeqInStream *inStream)
{
return SeqInStream_Read(inStream, p->check, XzFlags_GetCheckSize(f));
}
*/
static SRes Xz_ReadIndex2(CXzStream *p, const Byte *buf, size_t size, ISzAlloc *alloc)
{
size_t i, numBlocks, crcStartPos, pos = 1;
UInt32 crc;
if (size < 5 || buf[0] != 0)
return SZ_ERROR_ARCHIVE;
size -= 4;
crc = CrcCalc(buf, size);
if (crc != GetUi32(buf + size))
return SZ_ERROR_ARCHIVE;
{
UInt64 numBlocks64;
READ_VARINT_AND_CHECK(buf, pos, size, &numBlocks64);
numBlocks = (size_t)numBlocks64;
if (numBlocks != numBlocks64 || numBlocks * 2 > size)
return SZ_ERROR_ARCHIVE;
}
crcStartPos = pos;
Xz_Free(p, alloc);
if (numBlocks != 0)
{
p->numBlocks = numBlocks;
p->numBlocksAllocated = numBlocks;
p->blocks = alloc->Alloc(alloc, sizeof(CXzBlockSizes) * numBlocks);
if (p->blocks == 0)
return SZ_ERROR_MEM;
for (i = 0; i < numBlocks; i++)
{
CXzBlockSizes *block = &p->blocks[i];
READ_VARINT_AND_CHECK(buf, pos, size, &block->totalSize);
READ_VARINT_AND_CHECK(buf, pos, size, &block->unpackSize);
if (block->totalSize == 0)
return SZ_ERROR_ARCHIVE;
}
}
while ((pos & 3) != 0)
if (buf[pos++] != 0)
return SZ_ERROR_ARCHIVE;
return (pos == size) ? SZ_OK : SZ_ERROR_ARCHIVE;
}
static SRes Xz_ReadIndex(CXzStream *p, ILookInStream *stream, UInt64 indexSize, ISzAlloc *alloc)
{
SRes res;
size_t size;
Byte *buf;
if (indexSize > ((UInt32)1 << 31))
return SZ_ERROR_UNSUPPORTED;
size = (size_t)indexSize;
if (size != indexSize)
return SZ_ERROR_UNSUPPORTED;
buf = alloc->Alloc(alloc, size);
if (buf == 0)
return SZ_ERROR_MEM;
res = LookInStream_Read2(stream, buf, size, SZ_ERROR_UNSUPPORTED);
if (res == SZ_OK)
res = Xz_ReadIndex2(p, buf, size, alloc);
alloc->Free(alloc, buf);
return res;
}
static SRes SeekFromCur(ILookInStream *inStream, Int64 *res)
{
return inStream->Seek(inStream, res, SZ_SEEK_CUR);
}
static SRes Xz_ReadBackward(CXzStream *p, ILookInStream *stream, Int64 *startOffset, ISzAlloc *alloc)
{
UInt64 indexSize;
Byte buf[XZ_STREAM_FOOTER_SIZE];
if ((*startOffset & 3) != 0 || *startOffset < XZ_STREAM_FOOTER_SIZE)
return SZ_ERROR_NO_ARCHIVE;
*startOffset = -XZ_STREAM_FOOTER_SIZE;
RINOK(SeekFromCur(stream, startOffset));
RINOK(LookInStream_Read2(stream, buf, XZ_STREAM_FOOTER_SIZE, SZ_ERROR_NO_ARCHIVE));
if (memcmp(buf + 10, XZ_FOOTER_SIG, XZ_FOOTER_SIG_SIZE) != 0)
{
Int64 i = 0;
*startOffset += XZ_STREAM_FOOTER_SIZE;
for (;;)
{
int j;
size_t processedSize;
#define TEMP_BUF_SIZE (1 << 10)
Byte tempBuf[TEMP_BUF_SIZE];
if (*startOffset < XZ_STREAM_FOOTER_SIZE || i > (1 << 16))
return SZ_ERROR_NO_ARCHIVE;
processedSize = (*startOffset > TEMP_BUF_SIZE) ? TEMP_BUF_SIZE : (size_t)*startOffset;
i += processedSize;
*startOffset = -(Int64)processedSize;
RINOK(SeekFromCur(stream, startOffset));
RINOK(LookInStream_Read2(stream, tempBuf, processedSize, SZ_ERROR_NO_ARCHIVE));
for (j = (int)processedSize; j >= 0; j--)
if (tempBuf[j -1] != 0)
break;
if (j != 0)
{
if ((j & 3) != 0)
return SZ_ERROR_NO_ARCHIVE;
*startOffset += j;
if (*startOffset < XZ_STREAM_FOOTER_SIZE)
return SZ_ERROR_NO_ARCHIVE;
*startOffset -= XZ_STREAM_FOOTER_SIZE;
RINOK(stream->Seek(stream, startOffset, SZ_SEEK_SET));
RINOK(LookInStream_Read2(stream, buf, XZ_STREAM_FOOTER_SIZE, SZ_ERROR_NO_ARCHIVE));
if (memcmp(buf + 10, XZ_FOOTER_SIG, XZ_FOOTER_SIG_SIZE) != 0)
return SZ_ERROR_NO_ARCHIVE;
break;
}
}
}
p->flags = (CXzStreamFlags)GetBe16(buf + 8);
if (!XzFlags_IsSupported(p->flags))
return SZ_ERROR_UNSUPPORTED;
if (GetUi32(buf) != CrcCalc(buf + 4, 6))
return SZ_ERROR_ARCHIVE;
indexSize = ((UInt64)GetUi32(buf + 4) + 1) << 2;
*startOffset = -(Int64)(indexSize + XZ_STREAM_FOOTER_SIZE);
RINOK(SeekFromCur(stream, startOffset));
RINOK(Xz_ReadIndex(p, stream, indexSize, alloc));
{
UInt64 totalSize = Xz_GetPackSize(p);
UInt64 sum = XZ_STREAM_HEADER_SIZE + totalSize + indexSize;
if (totalSize == XZ_SIZE_OVERFLOW ||
sum >= ((UInt64)1 << 63) ||
totalSize >= ((UInt64)1 << 63))
return SZ_ERROR_ARCHIVE;
*startOffset = -(Int64)sum;
RINOK(SeekFromCur(stream, startOffset));
}
{
CXzStreamFlags headerFlags;
CSecToRead secToRead;
SecToRead_CreateVTable(&secToRead);
secToRead.realStream = stream;
RINOK(Xz_ReadHeader(&headerFlags, &secToRead.s));
return (p->flags == headerFlags) ? SZ_OK : SZ_ERROR_ARCHIVE;
}
}
/* ---------- Xz Streams ---------- */
void Xzs_Construct(CXzs *p)
{
p->num = p->numAllocated = 0;
p->streams = 0;
}
void Xzs_Free(CXzs *p, ISzAlloc *alloc)
{
size_t i;
for (i = 0; i < p->num; i++)
Xz_Free(&p->streams[i], alloc);
alloc->Free(alloc, p->streams);
p->num = p->numAllocated = 0;
p->streams = 0;
}
UInt64 Xzs_GetNumBlocks(const CXzs *p)
{
UInt64 num = 0;
size_t i;
for (i = 0; i < p->num; i++)
num += p->streams[i].numBlocks;
return num;
}
UInt64 Xzs_GetUnpackSize(const CXzs *p)
{
UInt64 size = 0;
size_t i;
for (i = 0; i < p->num; i++)
ADD_SIZE_CHECH(size, Xz_GetUnpackSize(&p->streams[i]));
return size;
}
/*
UInt64 Xzs_GetPackSize(const CXzs *p)
{
UInt64 size = 0;
size_t i;
for (i = 0; i < p->num; i++)
ADD_SIZE_CHECH(size, Xz_GetTotalSize(&p->streams[i]));
return size;
}
*/
SRes Xzs_ReadBackward(CXzs *p, ILookInStream *stream, Int64 *startOffset, ICompressProgress *progress, ISzAlloc *alloc)
{
Int64 endOffset = 0;
RINOK(stream->Seek(stream, &endOffset, SZ_SEEK_END));
*startOffset = endOffset;
for (;;)
{
CXzStream st;
SRes res;
Xz_Construct(&st);
res = Xz_ReadBackward(&st, stream, startOffset, alloc);
st.startOffset = *startOffset;
RINOK(res);
if (p->num == p->numAllocated)
{
size_t newNum = p->num + p->num / 4 + 1;
Byte *data = (Byte *)alloc->Alloc(alloc, newNum * sizeof(CXzStream));
if (data == 0)
return SZ_ERROR_MEM;
p->numAllocated = newNum;
memcpy(data, p->streams, p->num * sizeof(CXzStream));
alloc->Free(alloc, p->streams);
p->streams = (CXzStream *)data;
}
p->streams[p->num++] = st;
if (*startOffset == 0)
break;
RINOK(stream->Seek(stream, startOffset, SZ_SEEK_SET));
if (progress && progress->Progress(progress, endOffset - *startOffset, (UInt64)(Int64)-1) != SZ_OK)
return SZ_ERROR_PROGRESS;
}
return SZ_OK;
} |