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
Xz_ReadHeader(CXzStreamFlags * p,ISeqInStream * inStream)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
XzBlock_ReadHeader(CXzBlock * p,ISeqInStream * inStream,Bool * isIndex,UInt32 * headerSizeRes)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
Xz_GetUnpackSize(const CXzStream * p)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
Xz_GetPackSize(const CXzStream * p)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
Xz_ReadIndex2(CXzStream * p,const Byte * buf,size_t size,ISzAlloc * alloc)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
Xz_ReadIndex(CXzStream * p,ILookInStream * stream,UInt64 indexSize,ISzAlloc * alloc)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
LookInStream_SeekRead_ForArc(ILookInStream * stream,UInt64 offset,void * buf,size_t size)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
Xz_ReadBackward(CXzStream * p,ILookInStream * stream,Int64 * startOffset,ISzAlloc * alloc)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
Xzs_Construct(CXzs * p)235 void Xzs_Construct(CXzs *p)
236 {
237 p->num = p->numAllocated = 0;
238 p->streams = 0;
239 }
240
Xzs_Free(CXzs * p,ISzAlloc * alloc)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
Xzs_GetNumBlocks(const CXzs * p)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
Xzs_GetUnpackSize(const CXzs * p)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
Xzs_ReadBackward(CXzs * p,ILookInStream * stream,Int64 * startOffset,ICompressProgress * progress,ISzAlloc * alloc)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