1 /* XzIn.c - Xz input
2 2018-02-02 : 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
Xz_ReadHeader(CXzStreamFlags * p,ISeqInStream * inStream)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
XzBlock_ReadHeader(CXzBlock * p,ISeqInStream * inStream,Bool * isIndex,UInt32 * headerSizeRes)31 SRes XzBlock_ReadHeader(CXzBlock *p, ISeqInStream *inStream, Bool *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
Xz_GetUnpackSize(const CXzStream * p)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
Xz_GetPackSize(const CXzStream * p)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
Xz_ReadIndex2(CXzStream * p,const Byte * buf,size_t size,ISzAllocPtr alloc)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
Xz_ReadIndex(CXzStream * p,ILookInStream * stream,UInt64 indexSize,ISzAllocPtr alloc)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
LookInStream_SeekRead_ForArc(ILookInStream * stream,UInt64 offset,void * buf,size_t size)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
Xz_ReadBackward(CXzStream * p,ILookInStream * stream,Int64 * startOffset,ISzAllocPtr alloc)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
Xzs_Construct(CXzs * p)241 void Xzs_Construct(CXzs *p)
242 {
243 p->num = p->numAllocated = 0;
244 p->streams = 0;
245 }
246
Xzs_Free(CXzs * p,ISzAllocPtr alloc)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
Xzs_GetNumBlocks(const CXzs * p)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
Xzs_GetUnpackSize(const CXzs * p)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
Xzs_ReadBackward(CXzs * p,ILookInStream * stream,Int64 * startOffset,ICompressProgress * progress,ISzAllocPtr alloc)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