1 /* XzIn.c - Xz input 2 2014-12-30 : 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 SRes Xz_ReadHeader(CXzStreamFlags *p, ISeqInStream *inStream) 13 { 14 Byte sig[XZ_STREAM_HEADER_SIZE]; 15 RINOK(SeqInStream_Read2(inStream, sig, XZ_STREAM_HEADER_SIZE, SZ_ERROR_NO_ARCHIVE)); 16 if (memcmp(sig, XZ_SIG, XZ_SIG_SIZE) != 0) 17 return SZ_ERROR_NO_ARCHIVE; 18 return Xz_ParseHeader(p, sig); 19 } 20 21 #define READ_VARINT_AND_CHECK(buf, pos, size, res) \ 22 { unsigned s = Xz_ReadVarInt(buf + pos, size - pos, res); \ 23 if (s == 0) return SZ_ERROR_ARCHIVE; pos += s; } 24 25 SRes XzBlock_ReadHeader(CXzBlock *p, ISeqInStream *inStream, Bool *isIndex, UInt32 *headerSizeRes) 26 { 27 Byte header[XZ_BLOCK_HEADER_SIZE_MAX]; 28 unsigned headerSize; 29 *headerSizeRes = 0; 30 RINOK(SeqInStream_ReadByte(inStream, &header[0])); 31 headerSize = ((unsigned)header[0] << 2) + 4; 32 if (headerSize == 0) 33 { 34 *headerSizeRes = 1; 35 *isIndex = True; 36 return SZ_OK; 37 } 38 39 *isIndex = False; 40 *headerSizeRes = headerSize; 41 RINOK(SeqInStream_Read(inStream, header + 1, headerSize - 1)); 42 return XzBlock_Parse(p, header); 43 } 44 45 #define ADD_SIZE_CHECH(size, val) \ 46 { UInt64 newSize = size + (val); if (newSize < size) return XZ_SIZE_OVERFLOW; size = newSize; } 47 48 UInt64 Xz_GetUnpackSize(const CXzStream *p) 49 { 50 UInt64 size = 0; 51 size_t i; 52 for (i = 0; i < p->numBlocks; i++) 53 ADD_SIZE_CHECH(size, p->blocks[i].unpackSize); 54 return size; 55 } 56 57 UInt64 Xz_GetPackSize(const CXzStream *p) 58 { 59 UInt64 size = 0; 60 size_t i; 61 for (i = 0; i < p->numBlocks; i++) 62 ADD_SIZE_CHECH(size, (p->blocks[i].totalSize + 3) & ~(UInt64)3); 63 return size; 64 } 65 66 /* 67 SRes XzBlock_ReadFooter(CXzBlock *p, CXzStreamFlags f, ISeqInStream *inStream) 68 { 69 return SeqInStream_Read(inStream, p->check, XzFlags_GetCheckSize(f)); 70 } 71 */ 72 73 static SRes Xz_ReadIndex2(CXzStream *p, const Byte *buf, size_t size, ISzAlloc *alloc) 74 { 75 size_t i, numBlocks, pos = 1; 76 UInt32 crc; 77 78 if (size < 5 || buf[0] != 0) 79 return SZ_ERROR_ARCHIVE; 80 81 size -= 4; 82 crc = CrcCalc(buf, size); 83 if (crc != GetUi32(buf + size)) 84 return SZ_ERROR_ARCHIVE; 85 86 { 87 UInt64 numBlocks64; 88 READ_VARINT_AND_CHECK(buf, pos, size, &numBlocks64); 89 numBlocks = (size_t)numBlocks64; 90 if (numBlocks != numBlocks64 || numBlocks * 2 > size) 91 return SZ_ERROR_ARCHIVE; 92 } 93 94 Xz_Free(p, alloc); 95 if (numBlocks != 0) 96 { 97 p->numBlocks = numBlocks; 98 p->numBlocksAllocated = numBlocks; 99 p->blocks = alloc->Alloc(alloc, sizeof(CXzBlockSizes) * numBlocks); 100 if (p->blocks == 0) 101 return SZ_ERROR_MEM; 102 for (i = 0; i < numBlocks; i++) 103 { 104 CXzBlockSizes *block = &p->blocks[i]; 105 READ_VARINT_AND_CHECK(buf, pos, size, &block->totalSize); 106 READ_VARINT_AND_CHECK(buf, pos, size, &block->unpackSize); 107 if (block->totalSize == 0) 108 return SZ_ERROR_ARCHIVE; 109 } 110 } 111 while ((pos & 3) != 0) 112 if (buf[pos++] != 0) 113 return SZ_ERROR_ARCHIVE; 114 return (pos == size) ? SZ_OK : SZ_ERROR_ARCHIVE; 115 } 116 117 static SRes Xz_ReadIndex(CXzStream *p, ILookInStream *stream, UInt64 indexSize, ISzAlloc *alloc) 118 { 119 SRes res; 120 size_t size; 121 Byte *buf; 122 if (indexSize > ((UInt32)1 << 31)) 123 return SZ_ERROR_UNSUPPORTED; 124 size = (size_t)indexSize; 125 if (size != indexSize) 126 return SZ_ERROR_UNSUPPORTED; 127 buf = alloc->Alloc(alloc, size); 128 if (buf == 0) 129 return SZ_ERROR_MEM; 130 res = LookInStream_Read2(stream, buf, size, SZ_ERROR_UNSUPPORTED); 131 if (res == SZ_OK) 132 res = Xz_ReadIndex2(p, buf, size, alloc); 133 alloc->Free(alloc, buf); 134 return res; 135 } 136 137 static SRes SeekFromCur(ILookInStream *inStream, Int64 *res) 138 { 139 return inStream->Seek(inStream, res, SZ_SEEK_CUR); 140 } 141 142 static SRes Xz_ReadBackward(CXzStream *p, ILookInStream *stream, Int64 *startOffset, ISzAlloc *alloc) 143 { 144 UInt64 indexSize; 145 Byte buf[XZ_STREAM_FOOTER_SIZE]; 146 147 if ((*startOffset & 3) != 0 || *startOffset < XZ_STREAM_FOOTER_SIZE) 148 return SZ_ERROR_NO_ARCHIVE; 149 *startOffset = -XZ_STREAM_FOOTER_SIZE; 150 RINOK(SeekFromCur(stream, startOffset)); 151 152 RINOK(LookInStream_Read2(stream, buf, XZ_STREAM_FOOTER_SIZE, SZ_ERROR_NO_ARCHIVE)); 153 154 if (memcmp(buf + 10, XZ_FOOTER_SIG, XZ_FOOTER_SIG_SIZE) != 0) 155 { 156 UInt32 total = 0; 157 *startOffset += XZ_STREAM_FOOTER_SIZE; 158 for (;;) 159 { 160 size_t i; 161 #define TEMP_BUF_SIZE (1 << 10) 162 Byte tempBuf[TEMP_BUF_SIZE]; 163 if (*startOffset < XZ_STREAM_FOOTER_SIZE || total > (1 << 16)) 164 return SZ_ERROR_NO_ARCHIVE; 165 i = (*startOffset > TEMP_BUF_SIZE) ? TEMP_BUF_SIZE : (size_t)*startOffset; 166 total += (UInt32)i; 167 *startOffset = -(Int64)i; 168 RINOK(SeekFromCur(stream, startOffset)); 169 RINOK(LookInStream_Read2(stream, tempBuf, i, SZ_ERROR_NO_ARCHIVE)); 170 for (; i != 0; i--) 171 if (tempBuf[i - 1] != 0) 172 break; 173 if (i != 0) 174 { 175 if ((i & 3) != 0) 176 return SZ_ERROR_NO_ARCHIVE; 177 *startOffset += i; 178 break; 179 } 180 } 181 if (*startOffset < XZ_STREAM_FOOTER_SIZE) 182 return SZ_ERROR_NO_ARCHIVE; 183 *startOffset -= XZ_STREAM_FOOTER_SIZE; 184 RINOK(stream->Seek(stream, startOffset, SZ_SEEK_SET)); 185 RINOK(LookInStream_Read2(stream, buf, XZ_STREAM_FOOTER_SIZE, SZ_ERROR_NO_ARCHIVE)); 186 if (memcmp(buf + 10, XZ_FOOTER_SIG, XZ_FOOTER_SIG_SIZE) != 0) 187 return SZ_ERROR_NO_ARCHIVE; 188 } 189 190 p->flags = (CXzStreamFlags)GetBe16(buf + 8); 191 192 if (!XzFlags_IsSupported(p->flags)) 193 return SZ_ERROR_UNSUPPORTED; 194 195 if (GetUi32(buf) != CrcCalc(buf + 4, 6)) 196 return SZ_ERROR_ARCHIVE; 197 198 indexSize = ((UInt64)GetUi32(buf + 4) + 1) << 2; 199 200 *startOffset = -(Int64)(indexSize + XZ_STREAM_FOOTER_SIZE); 201 RINOK(SeekFromCur(stream, startOffset)); 202 203 RINOK(Xz_ReadIndex(p, stream, indexSize, alloc)); 204 205 { 206 UInt64 totalSize = Xz_GetPackSize(p); 207 UInt64 sum = XZ_STREAM_HEADER_SIZE + totalSize + indexSize; 208 if (totalSize == XZ_SIZE_OVERFLOW || 209 sum >= ((UInt64)1 << 63) || 210 totalSize >= ((UInt64)1 << 63)) 211 return SZ_ERROR_ARCHIVE; 212 *startOffset = -(Int64)sum; 213 RINOK(SeekFromCur(stream, startOffset)); 214 } 215 { 216 CXzStreamFlags headerFlags; 217 CSecToRead secToRead; 218 SecToRead_CreateVTable(&secToRead); 219 secToRead.realStream = stream; 220 221 RINOK(Xz_ReadHeader(&headerFlags, &secToRead.s)); 222 return (p->flags == headerFlags) ? SZ_OK : SZ_ERROR_ARCHIVE; 223 } 224 } 225 226 227 /* ---------- Xz Streams ---------- */ 228 229 void Xzs_Construct(CXzs *p) 230 { 231 p->num = p->numAllocated = 0; 232 p->streams = 0; 233 } 234 235 void Xzs_Free(CXzs *p, ISzAlloc *alloc) 236 { 237 size_t i; 238 for (i = 0; i < p->num; i++) 239 Xz_Free(&p->streams[i], alloc); 240 alloc->Free(alloc, p->streams); 241 p->num = p->numAllocated = 0; 242 p->streams = 0; 243 } 244 245 UInt64 Xzs_GetNumBlocks(const CXzs *p) 246 { 247 UInt64 num = 0; 248 size_t i; 249 for (i = 0; i < p->num; i++) 250 num += p->streams[i].numBlocks; 251 return num; 252 } 253 254 UInt64 Xzs_GetUnpackSize(const CXzs *p) 255 { 256 UInt64 size = 0; 257 size_t i; 258 for (i = 0; i < p->num; i++) 259 ADD_SIZE_CHECH(size, Xz_GetUnpackSize(&p->streams[i])); 260 return size; 261 } 262 263 /* 264 UInt64 Xzs_GetPackSize(const CXzs *p) 265 { 266 UInt64 size = 0; 267 size_t i; 268 for (i = 0; i < p->num; i++) 269 ADD_SIZE_CHECH(size, Xz_GetTotalSize(&p->streams[i])); 270 return size; 271 } 272 */ 273 274 SRes Xzs_ReadBackward(CXzs *p, ILookInStream *stream, Int64 *startOffset, ICompressProgress *progress, ISzAlloc *alloc) 275 { 276 Int64 endOffset = 0; 277 RINOK(stream->Seek(stream, &endOffset, SZ_SEEK_END)); 278 *startOffset = endOffset; 279 for (;;) 280 { 281 CXzStream st; 282 SRes res; 283 Xz_Construct(&st); 284 res = Xz_ReadBackward(&st, stream, startOffset, alloc); 285 st.startOffset = *startOffset; 286 RINOK(res); 287 if (p->num == p->numAllocated) 288 { 289 size_t newNum = p->num + p->num / 4 + 1; 290 Byte *data = (Byte *)alloc->Alloc(alloc, newNum * sizeof(CXzStream)); 291 if (data == 0) 292 return SZ_ERROR_MEM; 293 p->numAllocated = newNum; 294 if (p->num != 0) 295 memcpy(data, p->streams, p->num * sizeof(CXzStream)); 296 alloc->Free(alloc, p->streams); 297 p->streams = (CXzStream *)data; 298 } 299 p->streams[p->num++] = st; 300 if (*startOffset == 0) 301 break; 302 RINOK(stream->Seek(stream, startOffset, SZ_SEEK_SET)); 303 if (progress && progress->Progress(progress, endOffset - *startOffset, (UInt64)(Int64)-1) != SZ_OK) 304 return SZ_ERROR_PROGRESS; 305 } 306 return SZ_OK; 307 } 308
