1 /* XzIn.c - Xz input 2 2015-11-08 : 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 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 size_t i; 98 p->numBlocks = numBlocks; 99 p->numBlocksAllocated = numBlocks; 100 p->blocks = alloc->Alloc(alloc, sizeof(CXzBlockSizes) * numBlocks); 101 if (p->blocks == 0) 102 return SZ_ERROR_MEM; 103 for (i = 0; i < numBlocks; i++) 104 { 105 CXzBlockSizes *block = &p->blocks[i]; 106 READ_VARINT_AND_CHECK(buf, pos, size, &block->totalSize); 107 READ_VARINT_AND_CHECK(buf, pos, size, &block->unpackSize); 108 if (block->totalSize == 0) 109 return SZ_ERROR_ARCHIVE; 110 } 111 } 112 while ((pos & 3) != 0) 113 if (buf[pos++] != 0) 114 return SZ_ERROR_ARCHIVE; 115 return (pos == size) ? SZ_OK : SZ_ERROR_ARCHIVE; 116 } 117 118 static SRes Xz_ReadIndex(CXzStream *p, ILookInStream *stream, UInt64 indexSize, ISzAlloc *alloc) 119 { 120 SRes res; 121 size_t size; 122 Byte *buf; 123 if (indexSize > ((UInt32)1 << 31)) 124 return SZ_ERROR_UNSUPPORTED; 125 size = (size_t)indexSize; 126 if (size != indexSize) 127 return SZ_ERROR_UNSUPPORTED; 128 buf = alloc->Alloc(alloc, size); 129 if (buf == 0) 130 return SZ_ERROR_MEM; 131 res = LookInStream_Read2(stream, buf, size, SZ_ERROR_UNSUPPORTED); 132 if (res == SZ_OK) 133 res = Xz_ReadIndex2(p, buf, size, alloc); 134 alloc->Free(alloc, buf); 135 return res; 136 } 137 138 static SRes LookInStream_SeekRead_ForArc(ILookInStream *stream, UInt64 offset, void *buf, size_t size) 139 { 140 RINOK(LookInStream_SeekTo(stream, offset)); 141 return LookInStream_Read(stream, buf, size); 142 /* return LookInStream_Read2(stream, buf, size, SZ_ERROR_NO_ARCHIVE); */ 143 } 144 145 static SRes Xz_ReadBackward(CXzStream *p, ILookInStream *stream, Int64 *startOffset, ISzAlloc *alloc) 146 { 147 UInt64 indexSize; 148 Byte buf[XZ_STREAM_FOOTER_SIZE]; 149 UInt64 pos = *startOffset; 150 151 if ((pos & 3) != 0 || pos < XZ_STREAM_FOOTER_SIZE) 152 return SZ_ERROR_NO_ARCHIVE; 153 154 pos -= XZ_STREAM_FOOTER_SIZE; 155 RINOK(LookInStream_SeekRead_ForArc(stream, pos, buf, XZ_STREAM_FOOTER_SIZE)); 156 157 if (memcmp(buf + 10, XZ_FOOTER_SIG, XZ_FOOTER_SIG_SIZE) != 0) 158 { 159 UInt32 total = 0; 160 pos += XZ_STREAM_FOOTER_SIZE; 161 162 for (;;) 163 { 164 size_t i; 165 #define TEMP_BUF_SIZE (1 << 10) 166 Byte temp[TEMP_BUF_SIZE]; 167 168 i = (pos > TEMP_BUF_SIZE) ? TEMP_BUF_SIZE : (size_t)pos; 169 pos -= i; 170 RINOK(LookInStream_SeekRead_ForArc(stream, pos, temp, i)); 171 total += (UInt32)i; 172 for (; i != 0; i--) 173 if (temp[i - 1] != 0) 174 break; 175 if (i != 0) 176 { 177 if ((i & 3) != 0) 178 return SZ_ERROR_NO_ARCHIVE; 179 pos += i; 180 break; 181 } 182 if (pos < XZ_STREAM_FOOTER_SIZE || total > (1 << 16)) 183 return SZ_ERROR_NO_ARCHIVE; 184 } 185 186 if (pos < XZ_STREAM_FOOTER_SIZE) 187 return SZ_ERROR_NO_ARCHIVE; 188 pos -= XZ_STREAM_FOOTER_SIZE; 189 RINOK(LookInStream_SeekRead_ForArc(stream, pos, buf, XZ_STREAM_FOOTER_SIZE)); 190 if (memcmp(buf + 10, XZ_FOOTER_SIG, XZ_FOOTER_SIG_SIZE) != 0) 191 return SZ_ERROR_NO_ARCHIVE; 192 } 193 194 p->flags = (CXzStreamFlags)GetBe16(buf + 8); 195 196 if (!XzFlags_IsSupported(p->flags)) 197 return SZ_ERROR_UNSUPPORTED; 198 199 if (GetUi32(buf) != CrcCalc(buf + 4, 6)) 200 return SZ_ERROR_ARCHIVE; 201 202 indexSize = ((UInt64)GetUi32(buf + 4) + 1) << 2; 203 204 if (pos < indexSize) 205 return SZ_ERROR_ARCHIVE; 206 207 pos -= indexSize; 208 RINOK(LookInStream_SeekTo(stream, pos)); 209 RINOK(Xz_ReadIndex(p, stream, indexSize, alloc)); 210 211 { 212 UInt64 totalSize = Xz_GetPackSize(p); 213 if (totalSize == XZ_SIZE_OVERFLOW 214 || totalSize >= ((UInt64)1 << 63) 215 || pos < totalSize + XZ_STREAM_HEADER_SIZE) 216 return SZ_ERROR_ARCHIVE; 217 pos -= (totalSize + XZ_STREAM_HEADER_SIZE); 218 RINOK(LookInStream_SeekTo(stream, pos)); 219 *startOffset = pos; 220 } 221 { 222 CXzStreamFlags headerFlags; 223 CSecToRead secToRead; 224 SecToRead_CreateVTable(&secToRead); 225 secToRead.realStream = stream; 226 227 RINOK(Xz_ReadHeader(&headerFlags, &secToRead.s)); 228 return (p->flags == headerFlags) ? SZ_OK : SZ_ERROR_ARCHIVE; 229 } 230 } 231 232 233 /* ---------- Xz Streams ---------- */ 234 235 void Xzs_Construct(CXzs *p) 236 { 237 p->num = p->numAllocated = 0; 238 p->streams = 0; 239 } 240 241 void Xzs_Free(CXzs *p, ISzAlloc *alloc) 242 { 243 size_t i; 244 for (i = 0; i < p->num; i++) 245 Xz_Free(&p->streams[i], alloc); 246 alloc->Free(alloc, p->streams); 247 p->num = p->numAllocated = 0; 248 p->streams = 0; 249 } 250 251 UInt64 Xzs_GetNumBlocks(const CXzs *p) 252 { 253 UInt64 num = 0; 254 size_t i; 255 for (i = 0; i < p->num; i++) 256 num += p->streams[i].numBlocks; 257 return num; 258 } 259 260 UInt64 Xzs_GetUnpackSize(const CXzs *p) 261 { 262 UInt64 size = 0; 263 size_t i; 264 for (i = 0; i < p->num; i++) 265 ADD_SIZE_CHECH(size, Xz_GetUnpackSize(&p->streams[i])); 266 return size; 267 } 268 269 /* 270 UInt64 Xzs_GetPackSize(const CXzs *p) 271 { 272 UInt64 size = 0; 273 size_t i; 274 for (i = 0; i < p->num; i++) 275 ADD_SIZE_CHECH(size, Xz_GetTotalSize(&p->streams[i])); 276 return size; 277 } 278 */ 279 280 SRes Xzs_ReadBackward(CXzs *p, ILookInStream *stream, Int64 *startOffset, ICompressProgress *progress, ISzAlloc *alloc) 281 { 282 Int64 endOffset = 0; 283 RINOK(stream->Seek(stream, &endOffset, SZ_SEEK_END)); 284 *startOffset = endOffset; 285 for (;;) 286 { 287 CXzStream st; 288 SRes res; 289 Xz_Construct(&st); 290 res = Xz_ReadBackward(&st, stream, startOffset, alloc); 291 st.startOffset = *startOffset; 292 RINOK(res); 293 if (p->num == p->numAllocated) 294 { 295 size_t newNum = p->num + p->num / 4 + 1; 296 Byte *data = (Byte *)alloc->Alloc(alloc, newNum * sizeof(CXzStream)); 297 if (data == 0) 298 return SZ_ERROR_MEM; 299 p->numAllocated = newNum; 300 if (p->num != 0) 301 memcpy(data, p->streams, p->num * sizeof(CXzStream)); 302 alloc->Free(alloc, p->streams); 303 p->streams = (CXzStream *)data; 304 } 305 p->streams[p->num++] = st; 306 if (*startOffset == 0) 307 break; 308 RINOK(LookInStream_SeekTo(stream, *startOffset)); 309 if (progress && progress->Progress(progress, endOffset - *startOffset, (UInt64)(Int64)-1) != SZ_OK) 310 return SZ_ERROR_PROGRESS; 311 } 312 return SZ_OK; 313 } 314
