diff options
Diffstat (limited to 'lib/zlib_inflate/infblock.c')
-rw-r--r-- | lib/zlib_inflate/infblock.c | 361 |
1 files changed, 361 insertions, 0 deletions
diff --git a/lib/zlib_inflate/infblock.c b/lib/zlib_inflate/infblock.c new file mode 100644 index 000000000000..50f21ca4ef7f --- /dev/null +++ b/lib/zlib_inflate/infblock.c | |||
@@ -0,0 +1,361 @@ | |||
1 | /* infblock.c -- interpret and process block types to last block | ||
2 | * Copyright (C) 1995-1998 Mark Adler | ||
3 | * For conditions of distribution and use, see copyright notice in zlib.h | ||
4 | */ | ||
5 | |||
6 | #include <linux/zutil.h> | ||
7 | #include "infblock.h" | ||
8 | #include "inftrees.h" | ||
9 | #include "infcodes.h" | ||
10 | #include "infutil.h" | ||
11 | |||
12 | struct inflate_codes_state; | ||
13 | |||
14 | /* simplify the use of the inflate_huft type with some defines */ | ||
15 | #define exop word.what.Exop | ||
16 | #define bits word.what.Bits | ||
17 | |||
18 | /* Table for deflate from PKZIP's appnote.txt. */ | ||
19 | static const uInt border[] = { /* Order of the bit length code lengths */ | ||
20 | 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; | ||
21 | |||
22 | /* | ||
23 | Notes beyond the 1.93a appnote.txt: | ||
24 | |||
25 | 1. Distance pointers never point before the beginning of the output | ||
26 | stream. | ||
27 | 2. Distance pointers can point back across blocks, up to 32k away. | ||
28 | 3. There is an implied maximum of 7 bits for the bit length table and | ||
29 | 15 bits for the actual data. | ||
30 | 4. If only one code exists, then it is encoded using one bit. (Zero | ||
31 | would be more efficient, but perhaps a little confusing.) If two | ||
32 | codes exist, they are coded using one bit each (0 and 1). | ||
33 | 5. There is no way of sending zero distance codes--a dummy must be | ||
34 | sent if there are none. (History: a pre 2.0 version of PKZIP would | ||
35 | store blocks with no distance codes, but this was discovered to be | ||
36 | too harsh a criterion.) Valid only for 1.93a. 2.04c does allow | ||
37 | zero distance codes, which is sent as one code of zero bits in | ||
38 | length. | ||
39 | 6. There are up to 286 literal/length codes. Code 256 represents the | ||
40 | end-of-block. Note however that the static length tree defines | ||
41 | 288 codes just to fill out the Huffman codes. Codes 286 and 287 | ||
42 | cannot be used though, since there is no length base or extra bits | ||
43 | defined for them. Similarily, there are up to 30 distance codes. | ||
44 | However, static trees define 32 codes (all 5 bits) to fill out the | ||
45 | Huffman codes, but the last two had better not show up in the data. | ||
46 | 7. Unzip can check dynamic Huffman blocks for complete code sets. | ||
47 | The exception is that a single code would not be complete (see #4). | ||
48 | 8. The five bits following the block type is really the number of | ||
49 | literal codes sent minus 257. | ||
50 | 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits | ||
51 | (1+6+6). Therefore, to output three times the length, you output | ||
52 | three codes (1+1+1), whereas to output four times the same length, | ||
53 | you only need two codes (1+3). Hmm. | ||
54 | 10. In the tree reconstruction algorithm, Code = Code + Increment | ||
55 | only if BitLength(i) is not zero. (Pretty obvious.) | ||
56 | 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) | ||
57 | 12. Note: length code 284 can represent 227-258, but length code 285 | ||
58 | really is 258. The last length deserves its own, short code | ||
59 | since it gets used a lot in very redundant files. The length | ||
60 | 258 is special since 258 - 3 (the min match length) is 255. | ||
61 | 13. The literal/length and distance code bit lengths are read as a | ||
62 | single stream of lengths. It is possible (and advantageous) for | ||
63 | a repeat code (16, 17, or 18) to go across the boundary between | ||
64 | the two sets of lengths. | ||
65 | */ | ||
66 | |||
67 | |||
68 | void zlib_inflate_blocks_reset( | ||
69 | inflate_blocks_statef *s, | ||
70 | z_streamp z, | ||
71 | uLong *c | ||
72 | ) | ||
73 | { | ||
74 | if (c != NULL) | ||
75 | *c = s->check; | ||
76 | if (s->mode == CODES) | ||
77 | zlib_inflate_codes_free(s->sub.decode.codes, z); | ||
78 | s->mode = TYPE; | ||
79 | s->bitk = 0; | ||
80 | s->bitb = 0; | ||
81 | s->read = s->write = s->window; | ||
82 | if (s->checkfn != NULL) | ||
83 | z->adler = s->check = (*s->checkfn)(0L, NULL, 0); | ||
84 | } | ||
85 | |||
86 | inflate_blocks_statef *zlib_inflate_blocks_new( | ||
87 | z_streamp z, | ||
88 | check_func c, | ||
89 | uInt w | ||
90 | ) | ||
91 | { | ||
92 | inflate_blocks_statef *s; | ||
93 | |||
94 | s = &WS(z)->working_blocks_state; | ||
95 | s->hufts = WS(z)->working_hufts; | ||
96 | s->window = WS(z)->working_window; | ||
97 | s->end = s->window + w; | ||
98 | s->checkfn = c; | ||
99 | s->mode = TYPE; | ||
100 | zlib_inflate_blocks_reset(s, z, NULL); | ||
101 | return s; | ||
102 | } | ||
103 | |||
104 | |||
105 | int zlib_inflate_blocks( | ||
106 | inflate_blocks_statef *s, | ||
107 | z_streamp z, | ||
108 | int r | ||
109 | ) | ||
110 | { | ||
111 | uInt t; /* temporary storage */ | ||
112 | uLong b; /* bit buffer */ | ||
113 | uInt k; /* bits in bit buffer */ | ||
114 | Byte *p; /* input data pointer */ | ||
115 | uInt n; /* bytes available there */ | ||
116 | Byte *q; /* output window write pointer */ | ||
117 | uInt m; /* bytes to end of window or read pointer */ | ||
118 | |||
119 | /* copy input/output information to locals (UPDATE macro restores) */ | ||
120 | LOAD | ||
121 | |||
122 | /* process input based on current state */ | ||
123 | while (1) switch (s->mode) | ||
124 | { | ||
125 | case TYPE: | ||
126 | NEEDBITS(3) | ||
127 | t = (uInt)b & 7; | ||
128 | s->last = t & 1; | ||
129 | switch (t >> 1) | ||
130 | { | ||
131 | case 0: /* stored */ | ||
132 | DUMPBITS(3) | ||
133 | t = k & 7; /* go to byte boundary */ | ||
134 | DUMPBITS(t) | ||
135 | s->mode = LENS; /* get length of stored block */ | ||
136 | break; | ||
137 | case 1: /* fixed */ | ||
138 | { | ||
139 | uInt bl, bd; | ||
140 | inflate_huft *tl, *td; | ||
141 | |||
142 | zlib_inflate_trees_fixed(&bl, &bd, &tl, &td, s->hufts, z); | ||
143 | s->sub.decode.codes = zlib_inflate_codes_new(bl, bd, tl, td, z); | ||
144 | if (s->sub.decode.codes == NULL) | ||
145 | { | ||
146 | r = Z_MEM_ERROR; | ||
147 | LEAVE | ||
148 | } | ||
149 | } | ||
150 | DUMPBITS(3) | ||
151 | s->mode = CODES; | ||
152 | break; | ||
153 | case 2: /* dynamic */ | ||
154 | DUMPBITS(3) | ||
155 | s->mode = TABLE; | ||
156 | break; | ||
157 | case 3: /* illegal */ | ||
158 | DUMPBITS(3) | ||
159 | s->mode = B_BAD; | ||
160 | z->msg = (char*)"invalid block type"; | ||
161 | r = Z_DATA_ERROR; | ||
162 | LEAVE | ||
163 | } | ||
164 | break; | ||
165 | case LENS: | ||
166 | NEEDBITS(32) | ||
167 | if ((((~b) >> 16) & 0xffff) != (b & 0xffff)) | ||
168 | { | ||
169 | s->mode = B_BAD; | ||
170 | z->msg = (char*)"invalid stored block lengths"; | ||
171 | r = Z_DATA_ERROR; | ||
172 | LEAVE | ||
173 | } | ||
174 | s->sub.left = (uInt)b & 0xffff; | ||
175 | b = k = 0; /* dump bits */ | ||
176 | s->mode = s->sub.left ? STORED : (s->last ? DRY : TYPE); | ||
177 | break; | ||
178 | case STORED: | ||
179 | if (n == 0) | ||
180 | LEAVE | ||
181 | NEEDOUT | ||
182 | t = s->sub.left; | ||
183 | if (t > n) t = n; | ||
184 | if (t > m) t = m; | ||
185 | memcpy(q, p, t); | ||
186 | p += t; n -= t; | ||
187 | q += t; m -= t; | ||
188 | if ((s->sub.left -= t) != 0) | ||
189 | break; | ||
190 | s->mode = s->last ? DRY : TYPE; | ||
191 | break; | ||
192 | case TABLE: | ||
193 | NEEDBITS(14) | ||
194 | s->sub.trees.table = t = (uInt)b & 0x3fff; | ||
195 | #ifndef PKZIP_BUG_WORKAROUND | ||
196 | if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) | ||
197 | { | ||
198 | s->mode = B_BAD; | ||
199 | z->msg = (char*)"too many length or distance symbols"; | ||
200 | r = Z_DATA_ERROR; | ||
201 | LEAVE | ||
202 | } | ||
203 | #endif | ||
204 | { | ||
205 | s->sub.trees.blens = WS(z)->working_blens; | ||
206 | } | ||
207 | DUMPBITS(14) | ||
208 | s->sub.trees.index = 0; | ||
209 | s->mode = BTREE; | ||
210 | case BTREE: | ||
211 | while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10)) | ||
212 | { | ||
213 | NEEDBITS(3) | ||
214 | s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7; | ||
215 | DUMPBITS(3) | ||
216 | } | ||
217 | while (s->sub.trees.index < 19) | ||
218 | s->sub.trees.blens[border[s->sub.trees.index++]] = 0; | ||
219 | s->sub.trees.bb = 7; | ||
220 | t = zlib_inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb, | ||
221 | &s->sub.trees.tb, s->hufts, z); | ||
222 | if (t != Z_OK) | ||
223 | { | ||
224 | r = t; | ||
225 | if (r == Z_DATA_ERROR) | ||
226 | s->mode = B_BAD; | ||
227 | LEAVE | ||
228 | } | ||
229 | s->sub.trees.index = 0; | ||
230 | s->mode = DTREE; | ||
231 | case DTREE: | ||
232 | while (t = s->sub.trees.table, | ||
233 | s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)) | ||
234 | { | ||
235 | inflate_huft *h; | ||
236 | uInt i, j, c; | ||
237 | |||
238 | t = s->sub.trees.bb; | ||
239 | NEEDBITS(t) | ||
240 | h = s->sub.trees.tb + ((uInt)b & zlib_inflate_mask[t]); | ||
241 | t = h->bits; | ||
242 | c = h->base; | ||
243 | if (c < 16) | ||
244 | { | ||
245 | DUMPBITS(t) | ||
246 | s->sub.trees.blens[s->sub.trees.index++] = c; | ||
247 | } | ||
248 | else /* c == 16..18 */ | ||
249 | { | ||
250 | i = c == 18 ? 7 : c - 14; | ||
251 | j = c == 18 ? 11 : 3; | ||
252 | NEEDBITS(t + i) | ||
253 | DUMPBITS(t) | ||
254 | j += (uInt)b & zlib_inflate_mask[i]; | ||
255 | DUMPBITS(i) | ||
256 | i = s->sub.trees.index; | ||
257 | t = s->sub.trees.table; | ||
258 | if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || | ||
259 | (c == 16 && i < 1)) | ||
260 | { | ||
261 | s->mode = B_BAD; | ||
262 | z->msg = (char*)"invalid bit length repeat"; | ||
263 | r = Z_DATA_ERROR; | ||
264 | LEAVE | ||
265 | } | ||
266 | c = c == 16 ? s->sub.trees.blens[i - 1] : 0; | ||
267 | do { | ||
268 | s->sub.trees.blens[i++] = c; | ||
269 | } while (--j); | ||
270 | s->sub.trees.index = i; | ||
271 | } | ||
272 | } | ||
273 | s->sub.trees.tb = NULL; | ||
274 | { | ||
275 | uInt bl, bd; | ||
276 | inflate_huft *tl, *td; | ||
277 | inflate_codes_statef *c; | ||
278 | |||
279 | bl = 9; /* must be <= 9 for lookahead assumptions */ | ||
280 | bd = 6; /* must be <= 9 for lookahead assumptions */ | ||
281 | t = s->sub.trees.table; | ||
282 | t = zlib_inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), | ||
283 | s->sub.trees.blens, &bl, &bd, &tl, &td, | ||
284 | s->hufts, z); | ||
285 | if (t != Z_OK) | ||
286 | { | ||
287 | if (t == (uInt)Z_DATA_ERROR) | ||
288 | s->mode = B_BAD; | ||
289 | r = t; | ||
290 | LEAVE | ||
291 | } | ||
292 | if ((c = zlib_inflate_codes_new(bl, bd, tl, td, z)) == NULL) | ||
293 | { | ||
294 | r = Z_MEM_ERROR; | ||
295 | LEAVE | ||
296 | } | ||
297 | s->sub.decode.codes = c; | ||
298 | } | ||
299 | s->mode = CODES; | ||
300 | case CODES: | ||
301 | UPDATE | ||
302 | if ((r = zlib_inflate_codes(s, z, r)) != Z_STREAM_END) | ||
303 | return zlib_inflate_flush(s, z, r); | ||
304 | r = Z_OK; | ||
305 | zlib_inflate_codes_free(s->sub.decode.codes, z); | ||
306 | LOAD | ||
307 | if (!s->last) | ||
308 | { | ||
309 | s->mode = TYPE; | ||
310 | break; | ||
311 | } | ||
312 | s->mode = DRY; | ||
313 | case DRY: | ||
314 | FLUSH | ||
315 | if (s->read != s->write) | ||
316 | LEAVE | ||
317 | s->mode = B_DONE; | ||
318 | case B_DONE: | ||
319 | r = Z_STREAM_END; | ||
320 | LEAVE | ||
321 | case B_BAD: | ||
322 | r = Z_DATA_ERROR; | ||
323 | LEAVE | ||
324 | default: | ||
325 | r = Z_STREAM_ERROR; | ||
326 | LEAVE | ||
327 | } | ||
328 | } | ||
329 | |||
330 | |||
331 | int zlib_inflate_blocks_free( | ||
332 | inflate_blocks_statef *s, | ||
333 | z_streamp z | ||
334 | ) | ||
335 | { | ||
336 | zlib_inflate_blocks_reset(s, z, NULL); | ||
337 | return Z_OK; | ||
338 | } | ||
339 | |||
340 | |||
341 | void zlib_inflate_set_dictionary( | ||
342 | inflate_blocks_statef *s, | ||
343 | const Byte *d, | ||
344 | uInt n | ||
345 | ) | ||
346 | { | ||
347 | memcpy(s->window, d, n); | ||
348 | s->read = s->write = s->window + n; | ||
349 | } | ||
350 | |||
351 | |||
352 | /* Returns true if inflate is currently at the end of a block generated | ||
353 | * by Z_SYNC_FLUSH or Z_FULL_FLUSH. | ||
354 | * IN assertion: s != NULL | ||
355 | */ | ||
356 | int zlib_inflate_blocks_sync_point( | ||
357 | inflate_blocks_statef *s | ||
358 | ) | ||
359 | { | ||
360 | return s->mode == LENS; | ||
361 | } | ||