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
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 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
Xz_ReadIndex(CXzStream * p,ILookInStream * stream,UInt64 indexSize,ISzAlloc * alloc)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
SeekFromCur(ILookInStream * inStream,Int64 * res)137 static SRes SeekFromCur(ILookInStream *inStream, Int64 *res)
138 {
139 return inStream->Seek(inStream, res, SZ_SEEK_CUR);
140 }
141
Xz_ReadBackward(CXzStream * p,ILookInStream * stream,Int64 * startOffset,ISzAlloc * alloc)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
Xzs_Construct(CXzs * p)229 void Xzs_Construct(CXzs *p)
230 {
231 p->num = p->numAllocated = 0;
232 p->streams = 0;
233 }
234
Xzs_Free(CXzs * p,ISzAlloc * alloc)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
Xzs_GetNumBlocks(const CXzs * p)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
Xzs_GetUnpackSize(const CXzs * p)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
Xzs_ReadBackward(CXzs * p,ILookInStream * stream,Int64 * startOffset,ICompressProgress * progress,ISzAlloc * alloc)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