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 } 320
