nel/3rdparty/seven_zip/XzIn.c

   1 /* XzIn.c - Xz input
   2 2018-07-04 : Igor Pavlov : Public domain */
   3
   4 #include "Precomp.h"
   5
   6 #include <string.h>
   7
   8 #include "7zCrc.h"
   9 #include "CpuArch.h"
  10 #include "Xz.h"
  11
  12 /*
  13 #define XZ_FOOTER_SIG_CHECK(p) (memcmp((p), XZ_FOOTER_SIG, XZ_FOOTER_SIG_SIZE) == 0)
  14 */
  15 #define XZ_FOOTER_SIG_CHECK(p) ((p)[0] == XZ_FOOTER_SIG_0 && (p)[1] == XZ_FOOTER_SIG_1)
  16
  17
  18 SRes Xz_ReadHeader(CXzStreamFlags *p, ISeqInStream *inStream)
  19 {
  20   Byte sig[XZ_STREAM_HEADER_SIZE];
  21   RINOK(SeqInStream_Read2(inStream, sig, XZ_STREAM_HEADER_SIZE, SZ_ERROR_NO_ARCHIVE));
  22   if (memcmp(sig, XZ_SIG, XZ_SIG_SIZE) != 0)
  23     return SZ_ERROR_NO_ARCHIVE;
  24   return Xz_ParseHeader(p, sig);
  25 }
  26
  27 #define READ_VARINT_AND_CHECK(buf, pos, size, res) \
  28   { unsigned s = Xz_ReadVarInt(buf + pos, size - pos, res); \
  29   if (s == 0) return SZ_ERROR_ARCHIVE; pos += s; }
  30
  31 SRes XzBlock_ReadHeader(CXzBlock *p, ISeqInStream *inStream, BoolInt *isIndex, UInt32 *headerSizeRes)
  32 {
  33   Byte header[XZ_BLOCK_HEADER_SIZE_MAX];
  34   unsigned headerSize;
  35   *headerSizeRes = 0;
  36   RINOK(SeqInStream_ReadByte(inStream, &header[0]));
  37   headerSize = (unsigned)header[0];
  38   if (headerSize == 0)
  39   {
  40     *headerSizeRes = 1;
  41     *isIndex = True;
  42     return SZ_OK;
  43   }
  44
  45   *isIndex = False;
  46   headerSize = (headerSize << 2) + 4;
  47   *headerSizeRes = headerSize;
  48   RINOK(SeqInStream_Read(inStream, header + 1, headerSize - 1));
  49   return XzBlock_Parse(p, header);
  50 }
  51
  52 #define ADD_SIZE_CHECK(size, val) \
  53   { UInt64 newSize = size + (val); if (newSize < size) return XZ_SIZE_OVERFLOW; size = newSize; }
  54
  55 UInt64 Xz_GetUnpackSize(const CXzStream *p)
  56 {
  57   UInt64 size = 0;
  58   size_t i;
  59   for (i = 0; i < p->numBlocks; i++)
  60     ADD_SIZE_CHECK(size, p->blocks[i].unpackSize);
  61   return size;
  62 }
  63
  64 UInt64 Xz_GetPackSize(const CXzStream *p)
  65 {
  66   UInt64 size = 0;
  67   size_t i;
  68   for (i = 0; i < p->numBlocks; i++)
  69     ADD_SIZE_CHECK(size, (p->blocks[i].totalSize + 3) & ~(UInt64)3);
  70   return size;
  71 }
  72
  73 /*
  74 SRes XzBlock_ReadFooter(CXzBlock *p, CXzStreamFlags f, ISeqInStream *inStream)
  75 {
  76   return SeqInStream_Read(inStream, p->check, XzFlags_GetCheckSize(f));
  77 }
  78 */
  79
  80 static SRes Xz_ReadIndex2(CXzStream *p, const Byte *buf, size_t size, ISzAllocPtr alloc)
  81 {
  82   size_t numBlocks, pos = 1;
  83   UInt32 crc;
  84
  85   if (size < 5 || buf[0] != 0)
  86     return SZ_ERROR_ARCHIVE;
  87
  88   size -= 4;
  89   crc = CrcCalc(buf, size);
  90   if (crc != GetUi32(buf + size))
  91     return SZ_ERROR_ARCHIVE;
  92
  93   {
  94     UInt64 numBlocks64;
  95     READ_VARINT_AND_CHECK(buf, pos, size, &numBlocks64);
  96     numBlocks = (size_t)numBlocks64;
  97     if (numBlocks != numBlocks64 || numBlocks * 2 > size)
  98       return SZ_ERROR_ARCHIVE;
  99   }
 100
 101   Xz_Free(p, alloc);
 102   if (numBlocks != 0)
 103   {
 104     size_t i;
 105     p->numBlocks = numBlocks;
 106     p->blocks = (CXzBlockSizes *)ISzAlloc_Alloc(alloc, sizeof(CXzBlockSizes) * numBlocks);
 107     if (!p->blocks)
 108       return SZ_ERROR_MEM;
 109     for (i = 0; i < numBlocks; i++)
 110     {
 111       CXzBlockSizes *block = &p->blocks[i];
 112       READ_VARINT_AND_CHECK(buf, pos, size, &block->totalSize);
 113       READ_VARINT_AND_CHECK(buf, pos, size, &block->unpackSize);
 114       if (block->totalSize == 0)
 115         return SZ_ERROR_ARCHIVE;
 116     }
 117   }
 118   while ((pos & 3) != 0)
 119     if (buf[pos++] != 0)
 120       return SZ_ERROR_ARCHIVE;
 121   return (pos == size) ? SZ_OK : SZ_ERROR_ARCHIVE;
 122 }
 123
 124 static SRes Xz_ReadIndex(CXzStream *p, ILookInStream *stream, UInt64 indexSize, ISzAllocPtr alloc)
 125 {
 126   SRes res;
 127   size_t size;
 128   Byte *buf;
 129   if (indexSize > ((UInt32)1 << 31))
 130     return SZ_ERROR_UNSUPPORTED;
 131   size = (size_t)indexSize;
 132   if (size != indexSize)
 133     return SZ_ERROR_UNSUPPORTED;
 134   buf = (Byte *)ISzAlloc_Alloc(alloc, size);
 135   if (!buf)
 136     return SZ_ERROR_MEM;
 137   res = LookInStream_Read2(stream, buf, size, SZ_ERROR_UNSUPPORTED);
 138   if (res == SZ_OK)
 139     res = Xz_ReadIndex2(p, buf, size, alloc);
 140   ISzAlloc_Free(alloc, buf);
 141   return res;
 142 }
 143
 144 static SRes LookInStream_SeekRead_ForArc(ILookInStream *stream, UInt64 offset, void *buf, size_t size)
 145 {
 146   RINOK(LookInStream_SeekTo(stream, offset));
 147   return LookInStream_Read(stream, buf, size);
 148   /* return LookInStream_Read2(stream, buf, size, SZ_ERROR_NO_ARCHIVE); */
 149 }
 150
 151 static SRes Xz_ReadBackward(CXzStream *p, ILookInStream *stream, Int64 *startOffset, ISzAllocPtr alloc)
 152 {
 153   UInt64 indexSize;
 154   Byte buf[XZ_STREAM_FOOTER_SIZE];
 155   UInt64 pos = *startOffset;
 156
 157   if ((pos & 3) != 0 || pos < XZ_STREAM_FOOTER_SIZE)
 158     return SZ_ERROR_NO_ARCHIVE;
 159
 160   pos -= XZ_STREAM_FOOTER_SIZE;
 161   RINOK(LookInStream_SeekRead_ForArc(stream, pos, buf, XZ_STREAM_FOOTER_SIZE));
 162
 163   if (!XZ_FOOTER_SIG_CHECK(buf + 10))
 164   {
 165     UInt32 total = 0;
 166     pos += XZ_STREAM_FOOTER_SIZE;
 167
 168     for (;;)
 169     {
 170       size_t i;
 171       #define TEMP_BUF_SIZE (1 << 10)
 172       Byte temp[TEMP_BUF_SIZE];
 173
 174       i = (pos > TEMP_BUF_SIZE) ? TEMP_BUF_SIZE : (size_t)pos;
 175       pos -= i;
 176       RINOK(LookInStream_SeekRead_ForArc(stream, pos, temp, i));
 177       total += (UInt32)i;
 178       for (; i != 0; i--)
 179         if (temp[i - 1] != 0)
 180           break;
 181       if (i != 0)
 182       {
 183         if ((i & 3) != 0)
 184           return SZ_ERROR_NO_ARCHIVE;
 185         pos += i;
 186         break;
 187       }
 188       if (pos < XZ_STREAM_FOOTER_SIZE || total > (1 << 16))
 189         return SZ_ERROR_NO_ARCHIVE;
 190     }
 191
 192     if (pos < XZ_STREAM_FOOTER_SIZE)
 193       return SZ_ERROR_NO_ARCHIVE;
 194     pos -= XZ_STREAM_FOOTER_SIZE;
 195     RINOK(LookInStream_SeekRead_ForArc(stream, pos, buf, XZ_STREAM_FOOTER_SIZE));
 196     if (!XZ_FOOTER_SIG_CHECK(buf + 10))
 197       return SZ_ERROR_NO_ARCHIVE;
 198   }
 199
 200   p->flags = (CXzStreamFlags)GetBe16(buf + 8);
 201
 202   if (!XzFlags_IsSupported(p->flags))
 203     return SZ_ERROR_UNSUPPORTED;
 204
 205   if (GetUi32(buf) != CrcCalc(buf + 4, 6))
 206     return SZ_ERROR_ARCHIVE;
 207
 208   indexSize = ((UInt64)GetUi32(buf + 4) + 1) << 2;
 209
 210   if (pos < indexSize)
 211     return SZ_ERROR_ARCHIVE;
 212
 213   pos -= indexSize;
 214   RINOK(LookInStream_SeekTo(stream, pos));
 215   RINOK(Xz_ReadIndex(p, stream, indexSize, alloc));
 216
 217   {
 218     UInt64 totalSize = Xz_GetPackSize(p);
 219     if (totalSize == XZ_SIZE_OVERFLOW
 220         || totalSize >= ((UInt64)1 << 63)
 221         || pos < totalSize + XZ_STREAM_HEADER_SIZE)
 222       return SZ_ERROR_ARCHIVE;
 223     pos -= (totalSize + XZ_STREAM_HEADER_SIZE);
 224     RINOK(LookInStream_SeekTo(stream, pos));
 225     *startOffset = pos;
 226   }
 227   {
 228     CXzStreamFlags headerFlags;
 229     CSecToRead secToRead;
 230     SecToRead_CreateVTable(&secToRead);
 231     secToRead.realStream = stream;
 232
 233     RINOK(Xz_ReadHeader(&headerFlags, &secToRead.vt));
 234     return (p->flags == headerFlags) ? SZ_OK : SZ_ERROR_ARCHIVE;
 235   }
 236 }
 237
 238
 239 /* ---------- Xz Streams ---------- */
 240
 241 void Xzs_Construct(CXzs *p)
 242 {
 243   p->num = p->numAllocated = 0;
 244   p->streams = 0;
 245 }
 246
 247 void Xzs_Free(CXzs *p, ISzAllocPtr alloc)
 248 {
 249   size_t i;
 250   for (i = 0; i < p->num; i++)
 251     Xz_Free(&p->streams[i], alloc);
 252   ISzAlloc_Free(alloc, p->streams);
 253   p->num = p->numAllocated = 0;
 254   p->streams = 0;
 255 }
 256
 257 UInt64 Xzs_GetNumBlocks(const CXzs *p)
 258 {
 259   UInt64 num = 0;
 260   size_t i;
 261   for (i = 0; i < p->num; i++)
 262     num += p->streams[i].numBlocks;
 263   return num;
 264 }
 265
 266 UInt64 Xzs_GetUnpackSize(const CXzs *p)
 267 {
 268   UInt64 size = 0;
 269   size_t i;
 270   for (i = 0; i < p->num; i++)
 271     ADD_SIZE_CHECK(size, Xz_GetUnpackSize(&p->streams[i]));
 272   return size;
 273 }
 274
 275 /*
 276 UInt64 Xzs_GetPackSize(const CXzs *p)
 277 {
 278   UInt64 size = 0;
 279   size_t i;
 280   for (i = 0; i < p->num; i++)
 281     ADD_SIZE_CHECK(size, Xz_GetTotalSize(&p->streams[i]));
 282   return size;
 283 }
 284 */
 285
 286 SRes Xzs_ReadBackward(CXzs *p, ILookInStream *stream, Int64 *startOffset, ICompressProgress *progress, ISzAllocPtr alloc)
 287 {
 288   Int64 endOffset = 0;
 289   RINOK(ILookInStream_Seek(stream, &endOffset, SZ_SEEK_END));
 290   *startOffset = endOffset;
 291   for (;;)
 292   {
 293     CXzStream st;
 294     SRes res;
 295     Xz_Construct(&st);
 296     res = Xz_ReadBackward(&st, stream, startOffset, alloc);
 297     st.startOffset = *startOffset;
 298     RINOK(res);
 299     if (p->num == p->numAllocated)
 300     {
 301       size_t newNum = p->num + p->num / 4 + 1;
 302       Byte *data = (Byte *)ISzAlloc_Alloc(alloc, newNum * sizeof(CXzStream));
 303       if (!data)
 304         return SZ_ERROR_MEM;
 305       p->numAllocated = newNum;
 306       if (p->num != 0)
 307         memcpy(data, p->streams, p->num * sizeof(CXzStream));
 308       ISzAlloc_Free(alloc, p->streams);
 309       p->streams = (CXzStream *)data;
 310     }
 311     p->streams[p->num++] = st;
 312     if (*startOffset == 0)
 313       break;
 314     RINOK(LookInStream_SeekTo(stream, *startOffset));
 315     if (progress && ICompressProgress_Progress(progress, endOffset - *startOffset, (UInt64)(Int64)-1) != SZ_OK)
 316       return SZ_ERROR_PROGRESS;
 317   }
 318   return SZ_OK;
 319 }