Source code
Revision control
Copy as Markdown
Other Tools
/* XzIn.c - Xz input↩
2018-02-02 : Igor Pavlov : Public domain */↩
↩
#include "Precomp.h"↩
↩
#include <string.h>↩
↩
#include "7zCrc.h"↩
#include "CpuArch.h"↩
#include "Xz.h"↩
↩
/*↩
#define XZ_FOOTER_SIG_CHECK(p) (memcmp((p), XZ_FOOTER_SIG, XZ_FOOTER_SIG_SIZE) == 0)↩
*/↩
#define XZ_FOOTER_SIG_CHECK(p) ((p)[0] == XZ_FOOTER_SIG_0 && (p)[1] == XZ_FOOTER_SIG_1)↩
↩
↩
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];↩
if (headerSize == 0)↩
{↩
*headerSizeRes = 1;↩
*isIndex = True;↩
return SZ_OK;↩
}↩
↩
*isIndex = False;↩
headerSize = (headerSize << 2) + 4;↩
*headerSizeRes = headerSize;↩
RINOK(SeqInStream_Read(inStream, header + 1, headerSize - 1));↩
return XzBlock_Parse(p, header);↩
}↩
↩
#define ADD_SIZE_CHECK(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_CHECK(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_CHECK(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, ISzAllocPtr alloc)↩
{↩
size_t numBlocks, 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;↩
}↩
↩
Xz_Free(p, alloc);↩
if (numBlocks != 0)↩
{↩
size_t i;↩
p->numBlocks = numBlocks;↩
p->blocks = (CXzBlockSizes *)ISzAlloc_Alloc(alloc, sizeof(CXzBlockSizes) * numBlocks);↩
if (!p->blocks)↩
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, ISzAllocPtr 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 = (Byte *)ISzAlloc_Alloc(alloc, size);↩
if (!buf)↩
return SZ_ERROR_MEM;↩
res = LookInStream_Read2(stream, buf, size, SZ_ERROR_UNSUPPORTED);↩
if (res == SZ_OK)↩
res = Xz_ReadIndex2(p, buf, size, alloc);↩
ISzAlloc_Free(alloc, buf);↩
return res;↩
}↩
↩
static SRes LookInStream_SeekRead_ForArc(ILookInStream *stream, UInt64 offset, void *buf, size_t size)↩
{↩
RINOK(LookInStream_SeekTo(stream, offset));↩
return LookInStream_Read(stream, buf, size);↩
/* return LookInStream_Read2(stream, buf, size, SZ_ERROR_NO_ARCHIVE); */↩
}↩
↩
static SRes Xz_ReadBackward(CXzStream *p, ILookInStream *stream, Int64 *startOffset, ISzAllocPtr alloc)↩
{↩
UInt64 indexSize;↩
Byte buf[XZ_STREAM_FOOTER_SIZE];↩
UInt64 pos = *startOffset;↩
↩
if ((pos & 3) != 0 || pos < XZ_STREAM_FOOTER_SIZE)↩
return SZ_ERROR_NO_ARCHIVE;↩
↩
pos -= XZ_STREAM_FOOTER_SIZE;↩
RINOK(LookInStream_SeekRead_ForArc(stream, pos, buf, XZ_STREAM_FOOTER_SIZE));↩
↩
if (!XZ_FOOTER_SIG_CHECK(buf + 10))↩
{↩
UInt32 total = 0;↩
pos += XZ_STREAM_FOOTER_SIZE;↩
↩
for (;;)↩
{↩
size_t i;↩
#define TEMP_BUF_SIZE (1 << 10)↩
Byte temp[TEMP_BUF_SIZE];↩
↩
i = (pos > TEMP_BUF_SIZE) ? TEMP_BUF_SIZE : (size_t)pos;↩
pos -= i;↩
RINOK(LookInStream_SeekRead_ForArc(stream, pos, temp, i));↩
total += (UInt32)i;↩
for (; i != 0; i--)↩
if (temp[i - 1] != 0)↩
break;↩
if (i != 0)↩
{↩
if ((i & 3) != 0)↩
return SZ_ERROR_NO_ARCHIVE;↩
pos += i;↩
break;↩
}↩
if (pos < XZ_STREAM_FOOTER_SIZE || total > (1 << 16))↩
return SZ_ERROR_NO_ARCHIVE;↩
}↩
↩
if (pos < XZ_STREAM_FOOTER_SIZE)↩
return SZ_ERROR_NO_ARCHIVE;↩
pos -= XZ_STREAM_FOOTER_SIZE;↩
RINOK(LookInStream_SeekRead_ForArc(stream, pos, buf, XZ_STREAM_FOOTER_SIZE));↩
if (!XZ_FOOTER_SIG_CHECK(buf + 10))↩
return SZ_ERROR_NO_ARCHIVE;↩
}↩
↩
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;↩
↩
if (pos < indexSize)↩
return SZ_ERROR_ARCHIVE;↩
↩
pos -= indexSize;↩
RINOK(LookInStream_SeekTo(stream, pos));↩
RINOK(Xz_ReadIndex(p, stream, indexSize, alloc));↩
↩
{↩
UInt64 totalSize = Xz_GetPackSize(p);↩
if (totalSize == XZ_SIZE_OVERFLOW↩
|| totalSize >= ((UInt64)1 << 63)↩
|| pos < totalSize + XZ_STREAM_HEADER_SIZE)↩
return SZ_ERROR_ARCHIVE;↩
pos -= (totalSize + XZ_STREAM_HEADER_SIZE);↩
RINOK(LookInStream_SeekTo(stream, pos));↩
*startOffset = pos;↩
}↩
{↩
CXzStreamFlags headerFlags;↩
CSecToRead secToRead;↩
SecToRead_CreateVTable(&secToRead);↩
secToRead.realStream = stream;↩
↩
RINOK(Xz_ReadHeader(&headerFlags, &secToRead.vt));↩
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, ISzAllocPtr alloc)↩
{↩
size_t i;↩
for (i = 0; i < p->num; i++)↩
Xz_Free(&p->streams[i], alloc);↩
ISzAlloc_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_CHECK(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_CHECK(size, Xz_GetTotalSize(&p->streams[i]));↩
return size;↩
}↩
*/↩
↩
SRes Xzs_ReadBackward(CXzs *p, ILookInStream *stream, Int64 *startOffset, ICompressProgress *progress, ISzAllocPtr alloc)↩
{↩
Int64 endOffset = 0;↩
RINOK(ILookInStream_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 *)ISzAlloc_Alloc(alloc, newNum * sizeof(CXzStream));↩
if (!data)↩
return SZ_ERROR_MEM;↩
p->numAllocated = newNum;↩
if (p->num != 0)↩
memcpy(data, p->streams, p->num * sizeof(CXzStream));↩
ISzAlloc_Free(alloc, p->streams);↩
p->streams = (CXzStream *)data;↩
}↩
p->streams[p->num++] = st;↩
if (*startOffset == 0)↩
break;↩
RINOK(LookInStream_SeekTo(stream, *startOffset));↩
if (progress && ICompressProgress_Progress(progress, endOffset - *startOffset, (UInt64)(Int64)-1) != SZ_OK)↩
return SZ_ERROR_PROGRESS;↩
}↩
return SZ_OK;↩
}↩