/* XzIn.c - Xz input | |
2018-07-04 : 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, BoolInt *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; | |
} |