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4f3865fb RP |
1 | /* inflate.c -- zlib decompression |
2 | * Copyright (C) 1995-2005 Mark Adler | |
3 | * For conditions of distribution and use, see copyright notice in zlib.h | |
4 | * | |
5 | * Based on zlib 1.2.3 but modified for the Linux Kernel by | |
6 | * Richard Purdie <richard@openedhand.com> | |
7 | * | |
8 | * Changes mainly for static instead of dynamic memory allocation | |
9 | * | |
1da177e4 LT |
10 | */ |
11 | ||
1da177e4 | 12 | #include <linux/zutil.h> |
4f3865fb RP |
13 | #include "inftrees.h" |
14 | #include "inflate.h" | |
15 | #include "inffast.h" | |
1da177e4 LT |
16 | #include "infutil.h" |
17 | ||
18 | int zlib_inflate_workspacesize(void) | |
19 | { | |
4f3865fb | 20 | return sizeof(struct inflate_workspace); |
1da177e4 LT |
21 | } |
22 | ||
4f3865fb RP |
23 | int zlib_inflateReset(z_streamp strm) |
24 | { | |
25 | struct inflate_state *state; | |
26 | ||
27 | if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR; | |
28 | state = (struct inflate_state *)strm->state; | |
29 | strm->total_in = strm->total_out = state->total = 0; | |
30 | strm->msg = NULL; | |
31 | strm->adler = 1; /* to support ill-conceived Java test suite */ | |
32 | state->mode = HEAD; | |
33 | state->last = 0; | |
34 | state->havedict = 0; | |
35 | state->dmax = 32768U; | |
36 | state->hold = 0; | |
37 | state->bits = 0; | |
38 | state->lencode = state->distcode = state->next = state->codes; | |
1da177e4 | 39 | |
4f3865fb RP |
40 | /* Initialise Window */ |
41 | state->wsize = 1U << state->wbits; | |
42 | state->write = 0; | |
43 | state->whave = 0; | |
44 | ||
45 | return Z_OK; | |
46 | } | |
47 | ||
48 | #if 0 | |
49 | int zlib_inflatePrime(z_streamp strm, int bits, int value) | |
1da177e4 | 50 | { |
4f3865fb RP |
51 | struct inflate_state *state; |
52 | ||
53 | if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR; | |
54 | state = (struct inflate_state *)strm->state; | |
55 | if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR; | |
56 | value &= (1L << bits) - 1; | |
57 | state->hold += value << state->bits; | |
58 | state->bits += bits; | |
59 | return Z_OK; | |
1da177e4 | 60 | } |
4f3865fb RP |
61 | #endif |
62 | ||
63 | int zlib_inflateInit2(z_streamp strm, int windowBits) | |
64 | { | |
65 | struct inflate_state *state; | |
66 | ||
67 | if (strm == NULL) return Z_STREAM_ERROR; | |
68 | strm->msg = NULL; /* in case we return an error */ | |
69 | ||
70 | state = &WS(strm)->inflate_state; | |
71 | strm->state = (struct internal_state *)state; | |
72 | ||
73 | if (windowBits < 0) { | |
74 | state->wrap = 0; | |
75 | windowBits = -windowBits; | |
76 | } | |
77 | else { | |
78 | state->wrap = (windowBits >> 4) + 1; | |
79 | } | |
80 | if (windowBits < 8 || windowBits > 15) { | |
81 | return Z_STREAM_ERROR; | |
82 | } | |
83 | state->wbits = (unsigned)windowBits; | |
84 | state->window = &WS(strm)->working_window[0]; | |
1da177e4 | 85 | |
4f3865fb RP |
86 | return zlib_inflateReset(strm); |
87 | } | |
1da177e4 | 88 | |
4f3865fb RP |
89 | /* |
90 | Return state with length and distance decoding tables and index sizes set to | |
91 | fixed code decoding. This returns fixed tables from inffixed.h. | |
92 | */ | |
93 | static void zlib_fixedtables(struct inflate_state *state) | |
1da177e4 | 94 | { |
4f3865fb RP |
95 | # include "inffixed.h" |
96 | state->lencode = lenfix; | |
97 | state->lenbits = 9; | |
98 | state->distcode = distfix; | |
99 | state->distbits = 5; | |
1da177e4 LT |
100 | } |
101 | ||
102 | ||
4f3865fb RP |
103 | /* |
104 | Update the window with the last wsize (normally 32K) bytes written before | |
105 | returning. This is only called when a window is already in use, or when | |
106 | output has been written during this inflate call, but the end of the deflate | |
107 | stream has not been reached yet. It is also called to window dictionary data | |
108 | when a dictionary is loaded. | |
109 | ||
110 | Providing output buffers larger than 32K to inflate() should provide a speed | |
111 | advantage, since only the last 32K of output is copied to the sliding window | |
112 | upon return from inflate(), and since all distances after the first 32K of | |
113 | output will fall in the output data, making match copies simpler and faster. | |
114 | The advantage may be dependent on the size of the processor's data caches. | |
115 | */ | |
116 | static void zlib_updatewindow(z_streamp strm, unsigned out) | |
1da177e4 | 117 | { |
4f3865fb RP |
118 | struct inflate_state *state; |
119 | unsigned copy, dist; | |
120 | ||
121 | state = (struct inflate_state *)strm->state; | |
122 | ||
123 | /* copy state->wsize or less output bytes into the circular window */ | |
124 | copy = out - strm->avail_out; | |
125 | if (copy >= state->wsize) { | |
126 | memcpy(state->window, strm->next_out - state->wsize, state->wsize); | |
127 | state->write = 0; | |
128 | state->whave = state->wsize; | |
129 | } | |
130 | else { | |
131 | dist = state->wsize - state->write; | |
132 | if (dist > copy) dist = copy; | |
133 | memcpy(state->window + state->write, strm->next_out - copy, dist); | |
134 | copy -= dist; | |
135 | if (copy) { | |
136 | memcpy(state->window, strm->next_out - copy, copy); | |
137 | state->write = copy; | |
138 | state->whave = state->wsize; | |
139 | } | |
140 | else { | |
141 | state->write += dist; | |
142 | if (state->write == state->wsize) state->write = 0; | |
143 | if (state->whave < state->wsize) state->whave += dist; | |
144 | } | |
145 | } | |
1da177e4 LT |
146 | } |
147 | ||
148 | ||
149 | /* | |
150 | * At the end of a Deflate-compressed PPP packet, we expect to have seen | |
151 | * a `stored' block type value but not the (zero) length bytes. | |
152 | */ | |
4f3865fb RP |
153 | /* |
154 | Returns true if inflate is currently at the end of a block generated by | |
155 | Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP | |
156 | implementation to provide an additional safety check. PPP uses | |
157 | Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored | |
158 | block. When decompressing, PPP checks that at the end of input packet, | |
159 | inflate is waiting for these length bytes. | |
160 | */ | |
161 | static int zlib_inflateSyncPacket(z_streamp strm) | |
1da177e4 | 162 | { |
4f3865fb RP |
163 | struct inflate_state *state; |
164 | ||
165 | if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR; | |
166 | state = (struct inflate_state *)strm->state; | |
167 | ||
168 | if (state->mode == STORED && state->bits == 0) { | |
169 | state->mode = TYPE; | |
170 | return Z_OK; | |
171 | } | |
172 | return Z_DATA_ERROR; | |
173 | } | |
174 | ||
175 | /* Macros for inflate(): */ | |
176 | ||
177 | /* check function to use adler32() for zlib or crc32() for gzip */ | |
178 | #define UPDATE(check, buf, len) zlib_adler32(check, buf, len) | |
179 | ||
180 | /* Load registers with state in inflate() for speed */ | |
181 | #define LOAD() \ | |
182 | do { \ | |
183 | put = strm->next_out; \ | |
184 | left = strm->avail_out; \ | |
185 | next = strm->next_in; \ | |
186 | have = strm->avail_in; \ | |
187 | hold = state->hold; \ | |
188 | bits = state->bits; \ | |
189 | } while (0) | |
190 | ||
191 | /* Restore state from registers in inflate() */ | |
192 | #define RESTORE() \ | |
193 | do { \ | |
194 | strm->next_out = put; \ | |
195 | strm->avail_out = left; \ | |
196 | strm->next_in = next; \ | |
197 | strm->avail_in = have; \ | |
198 | state->hold = hold; \ | |
199 | state->bits = bits; \ | |
200 | } while (0) | |
201 | ||
202 | /* Clear the input bit accumulator */ | |
203 | #define INITBITS() \ | |
204 | do { \ | |
205 | hold = 0; \ | |
206 | bits = 0; \ | |
207 | } while (0) | |
208 | ||
209 | /* Get a byte of input into the bit accumulator, or return from inflate() | |
210 | if there is no input available. */ | |
211 | #define PULLBYTE() \ | |
212 | do { \ | |
213 | if (have == 0) goto inf_leave; \ | |
214 | have--; \ | |
215 | hold += (unsigned long)(*next++) << bits; \ | |
216 | bits += 8; \ | |
217 | } while (0) | |
218 | ||
219 | /* Assure that there are at least n bits in the bit accumulator. If there is | |
220 | not enough available input to do that, then return from inflate(). */ | |
221 | #define NEEDBITS(n) \ | |
222 | do { \ | |
223 | while (bits < (unsigned)(n)) \ | |
224 | PULLBYTE(); \ | |
225 | } while (0) | |
226 | ||
227 | /* Return the low n bits of the bit accumulator (n < 16) */ | |
228 | #define BITS(n) \ | |
229 | ((unsigned)hold & ((1U << (n)) - 1)) | |
230 | ||
231 | /* Remove n bits from the bit accumulator */ | |
232 | #define DROPBITS(n) \ | |
233 | do { \ | |
234 | hold >>= (n); \ | |
235 | bits -= (unsigned)(n); \ | |
236 | } while (0) | |
237 | ||
238 | /* Remove zero to seven bits as needed to go to a byte boundary */ | |
239 | #define BYTEBITS() \ | |
240 | do { \ | |
241 | hold >>= bits & 7; \ | |
242 | bits -= bits & 7; \ | |
243 | } while (0) | |
244 | ||
245 | /* Reverse the bytes in a 32-bit value */ | |
246 | #define REVERSE(q) \ | |
247 | ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \ | |
248 | (((q) & 0xff00) << 8) + (((q) & 0xff) << 24)) | |
249 | ||
250 | /* | |
251 | inflate() uses a state machine to process as much input data and generate as | |
252 | much output data as possible before returning. The state machine is | |
253 | structured roughly as follows: | |
254 | ||
255 | for (;;) switch (state) { | |
256 | ... | |
257 | case STATEn: | |
258 | if (not enough input data or output space to make progress) | |
259 | return; | |
260 | ... make progress ... | |
261 | state = STATEm; | |
262 | break; | |
263 | ... | |
264 | } | |
265 | ||
266 | so when inflate() is called again, the same case is attempted again, and | |
267 | if the appropriate resources are provided, the machine proceeds to the | |
268 | next state. The NEEDBITS() macro is usually the way the state evaluates | |
269 | whether it can proceed or should return. NEEDBITS() does the return if | |
270 | the requested bits are not available. The typical use of the BITS macros | |
271 | is: | |
272 | ||
273 | NEEDBITS(n); | |
274 | ... do something with BITS(n) ... | |
275 | DROPBITS(n); | |
276 | ||
277 | where NEEDBITS(n) either returns from inflate() if there isn't enough | |
278 | input left to load n bits into the accumulator, or it continues. BITS(n) | |
279 | gives the low n bits in the accumulator. When done, DROPBITS(n) drops | |
280 | the low n bits off the accumulator. INITBITS() clears the accumulator | |
281 | and sets the number of available bits to zero. BYTEBITS() discards just | |
282 | enough bits to put the accumulator on a byte boundary. After BYTEBITS() | |
283 | and a NEEDBITS(8), then BITS(8) would return the next byte in the stream. | |
284 | ||
285 | NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return | |
286 | if there is no input available. The decoding of variable length codes uses | |
287 | PULLBYTE() directly in order to pull just enough bytes to decode the next | |
288 | code, and no more. | |
289 | ||
290 | Some states loop until they get enough input, making sure that enough | |
291 | state information is maintained to continue the loop where it left off | |
292 | if NEEDBITS() returns in the loop. For example, want, need, and keep | |
293 | would all have to actually be part of the saved state in case NEEDBITS() | |
294 | returns: | |
295 | ||
296 | case STATEw: | |
297 | while (want < need) { | |
298 | NEEDBITS(n); | |
299 | keep[want++] = BITS(n); | |
300 | DROPBITS(n); | |
301 | } | |
302 | state = STATEx; | |
303 | case STATEx: | |
304 | ||
305 | As shown above, if the next state is also the next case, then the break | |
306 | is omitted. | |
307 | ||
308 | A state may also return if there is not enough output space available to | |
309 | complete that state. Those states are copying stored data, writing a | |
310 | literal byte, and copying a matching string. | |
311 | ||
312 | When returning, a "goto inf_leave" is used to update the total counters, | |
313 | update the check value, and determine whether any progress has been made | |
314 | during that inflate() call in order to return the proper return code. | |
315 | Progress is defined as a change in either strm->avail_in or strm->avail_out. | |
316 | When there is a window, goto inf_leave will update the window with the last | |
317 | output written. If a goto inf_leave occurs in the middle of decompression | |
318 | and there is no window currently, goto inf_leave will create one and copy | |
319 | output to the window for the next call of inflate(). | |
320 | ||
321 | In this implementation, the flush parameter of inflate() only affects the | |
322 | return code (per zlib.h). inflate() always writes as much as possible to | |
323 | strm->next_out, given the space available and the provided input--the effect | |
324 | documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers | |
325 | the allocation of and copying into a sliding window until necessary, which | |
326 | provides the effect documented in zlib.h for Z_FINISH when the entire input | |
327 | stream available. So the only thing the flush parameter actually does is: | |
328 | when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it | |
329 | will return Z_BUF_ERROR if it has not reached the end of the stream. | |
330 | */ | |
331 | ||
332 | int zlib_inflate(z_streamp strm, int flush) | |
333 | { | |
334 | struct inflate_state *state; | |
8336793b DV |
335 | const unsigned char *next; /* next input */ |
336 | unsigned char *put; /* next output */ | |
4f3865fb RP |
337 | unsigned have, left; /* available input and output */ |
338 | unsigned long hold; /* bit buffer */ | |
339 | unsigned bits; /* bits in bit buffer */ | |
340 | unsigned in, out; /* save starting available input and output */ | |
341 | unsigned copy; /* number of stored or match bytes to copy */ | |
8336793b | 342 | unsigned char *from; /* where to copy match bytes from */ |
4f3865fb RP |
343 | code this; /* current decoding table entry */ |
344 | code last; /* parent table entry */ | |
345 | unsigned len; /* length to copy for repeats, bits to drop */ | |
346 | int ret; /* return code */ | |
347 | static const unsigned short order[19] = /* permutation of code lengths */ | |
348 | {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; | |
349 | ||
31925c88 PK |
350 | /* Do not check for strm->next_out == NULL here as ppc zImage |
351 | inflates to strm->next_out = 0 */ | |
352 | ||
353 | if (strm == NULL || strm->state == NULL || | |
4f3865fb RP |
354 | (strm->next_in == NULL && strm->avail_in != 0)) |
355 | return Z_STREAM_ERROR; | |
356 | ||
357 | state = (struct inflate_state *)strm->state; | |
358 | ||
359 | if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */ | |
360 | LOAD(); | |
361 | in = have; | |
362 | out = left; | |
363 | ret = Z_OK; | |
364 | for (;;) | |
365 | switch (state->mode) { | |
366 | case HEAD: | |
367 | if (state->wrap == 0) { | |
368 | state->mode = TYPEDO; | |
369 | break; | |
370 | } | |
371 | NEEDBITS(16); | |
372 | if ( | |
373 | ((BITS(8) << 8) + (hold >> 8)) % 31) { | |
374 | strm->msg = (char *)"incorrect header check"; | |
375 | state->mode = BAD; | |
376 | break; | |
377 | } | |
378 | if (BITS(4) != Z_DEFLATED) { | |
379 | strm->msg = (char *)"unknown compression method"; | |
380 | state->mode = BAD; | |
381 | break; | |
382 | } | |
383 | DROPBITS(4); | |
384 | len = BITS(4) + 8; | |
385 | if (len > state->wbits) { | |
386 | strm->msg = (char *)"invalid window size"; | |
387 | state->mode = BAD; | |
388 | break; | |
389 | } | |
390 | state->dmax = 1U << len; | |
391 | strm->adler = state->check = zlib_adler32(0L, NULL, 0); | |
392 | state->mode = hold & 0x200 ? DICTID : TYPE; | |
393 | INITBITS(); | |
394 | break; | |
395 | case DICTID: | |
396 | NEEDBITS(32); | |
397 | strm->adler = state->check = REVERSE(hold); | |
398 | INITBITS(); | |
399 | state->mode = DICT; | |
400 | case DICT: | |
401 | if (state->havedict == 0) { | |
402 | RESTORE(); | |
403 | return Z_NEED_DICT; | |
404 | } | |
405 | strm->adler = state->check = zlib_adler32(0L, NULL, 0); | |
406 | state->mode = TYPE; | |
407 | case TYPE: | |
408 | if (flush == Z_BLOCK) goto inf_leave; | |
409 | case TYPEDO: | |
410 | if (state->last) { | |
411 | BYTEBITS(); | |
412 | state->mode = CHECK; | |
413 | break; | |
414 | } | |
415 | NEEDBITS(3); | |
416 | state->last = BITS(1); | |
417 | DROPBITS(1); | |
418 | switch (BITS(2)) { | |
419 | case 0: /* stored block */ | |
420 | state->mode = STORED; | |
421 | break; | |
422 | case 1: /* fixed block */ | |
423 | zlib_fixedtables(state); | |
424 | state->mode = LEN; /* decode codes */ | |
425 | break; | |
426 | case 2: /* dynamic block */ | |
427 | state->mode = TABLE; | |
428 | break; | |
429 | case 3: | |
430 | strm->msg = (char *)"invalid block type"; | |
431 | state->mode = BAD; | |
432 | } | |
433 | DROPBITS(2); | |
434 | break; | |
435 | case STORED: | |
436 | BYTEBITS(); /* go to byte boundary */ | |
437 | NEEDBITS(32); | |
438 | if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { | |
439 | strm->msg = (char *)"invalid stored block lengths"; | |
440 | state->mode = BAD; | |
441 | break; | |
442 | } | |
443 | state->length = (unsigned)hold & 0xffff; | |
444 | INITBITS(); | |
445 | state->mode = COPY; | |
446 | case COPY: | |
447 | copy = state->length; | |
448 | if (copy) { | |
449 | if (copy > have) copy = have; | |
450 | if (copy > left) copy = left; | |
451 | if (copy == 0) goto inf_leave; | |
452 | memcpy(put, next, copy); | |
453 | have -= copy; | |
454 | next += copy; | |
455 | left -= copy; | |
456 | put += copy; | |
457 | state->length -= copy; | |
458 | break; | |
459 | } | |
460 | state->mode = TYPE; | |
461 | break; | |
462 | case TABLE: | |
463 | NEEDBITS(14); | |
464 | state->nlen = BITS(5) + 257; | |
465 | DROPBITS(5); | |
466 | state->ndist = BITS(5) + 1; | |
467 | DROPBITS(5); | |
468 | state->ncode = BITS(4) + 4; | |
469 | DROPBITS(4); | |
470 | #ifndef PKZIP_BUG_WORKAROUND | |
471 | if (state->nlen > 286 || state->ndist > 30) { | |
472 | strm->msg = (char *)"too many length or distance symbols"; | |
473 | state->mode = BAD; | |
474 | break; | |
475 | } | |
476 | #endif | |
477 | state->have = 0; | |
478 | state->mode = LENLENS; | |
479 | case LENLENS: | |
480 | while (state->have < state->ncode) { | |
481 | NEEDBITS(3); | |
482 | state->lens[order[state->have++]] = (unsigned short)BITS(3); | |
483 | DROPBITS(3); | |
484 | } | |
485 | while (state->have < 19) | |
486 | state->lens[order[state->have++]] = 0; | |
487 | state->next = state->codes; | |
488 | state->lencode = (code const *)(state->next); | |
489 | state->lenbits = 7; | |
490 | ret = zlib_inflate_table(CODES, state->lens, 19, &(state->next), | |
491 | &(state->lenbits), state->work); | |
492 | if (ret) { | |
493 | strm->msg = (char *)"invalid code lengths set"; | |
494 | state->mode = BAD; | |
495 | break; | |
496 | } | |
497 | state->have = 0; | |
498 | state->mode = CODELENS; | |
499 | case CODELENS: | |
500 | while (state->have < state->nlen + state->ndist) { | |
501 | for (;;) { | |
502 | this = state->lencode[BITS(state->lenbits)]; | |
503 | if ((unsigned)(this.bits) <= bits) break; | |
504 | PULLBYTE(); | |
505 | } | |
506 | if (this.val < 16) { | |
507 | NEEDBITS(this.bits); | |
508 | DROPBITS(this.bits); | |
509 | state->lens[state->have++] = this.val; | |
510 | } | |
511 | else { | |
512 | if (this.val == 16) { | |
513 | NEEDBITS(this.bits + 2); | |
514 | DROPBITS(this.bits); | |
515 | if (state->have == 0) { | |
516 | strm->msg = (char *)"invalid bit length repeat"; | |
517 | state->mode = BAD; | |
518 | break; | |
519 | } | |
520 | len = state->lens[state->have - 1]; | |
521 | copy = 3 + BITS(2); | |
522 | DROPBITS(2); | |
523 | } | |
524 | else if (this.val == 17) { | |
525 | NEEDBITS(this.bits + 3); | |
526 | DROPBITS(this.bits); | |
527 | len = 0; | |
528 | copy = 3 + BITS(3); | |
529 | DROPBITS(3); | |
530 | } | |
531 | else { | |
532 | NEEDBITS(this.bits + 7); | |
533 | DROPBITS(this.bits); | |
534 | len = 0; | |
535 | copy = 11 + BITS(7); | |
536 | DROPBITS(7); | |
537 | } | |
538 | if (state->have + copy > state->nlen + state->ndist) { | |
539 | strm->msg = (char *)"invalid bit length repeat"; | |
540 | state->mode = BAD; | |
541 | break; | |
542 | } | |
543 | while (copy--) | |
544 | state->lens[state->have++] = (unsigned short)len; | |
545 | } | |
546 | } | |
547 | ||
548 | /* handle error breaks in while */ | |
549 | if (state->mode == BAD) break; | |
550 | ||
551 | /* build code tables */ | |
552 | state->next = state->codes; | |
553 | state->lencode = (code const *)(state->next); | |
554 | state->lenbits = 9; | |
555 | ret = zlib_inflate_table(LENS, state->lens, state->nlen, &(state->next), | |
556 | &(state->lenbits), state->work); | |
557 | if (ret) { | |
558 | strm->msg = (char *)"invalid literal/lengths set"; | |
559 | state->mode = BAD; | |
560 | break; | |
561 | } | |
562 | state->distcode = (code const *)(state->next); | |
563 | state->distbits = 6; | |
564 | ret = zlib_inflate_table(DISTS, state->lens + state->nlen, state->ndist, | |
565 | &(state->next), &(state->distbits), state->work); | |
566 | if (ret) { | |
567 | strm->msg = (char *)"invalid distances set"; | |
568 | state->mode = BAD; | |
569 | break; | |
570 | } | |
571 | state->mode = LEN; | |
572 | case LEN: | |
573 | if (have >= 6 && left >= 258) { | |
574 | RESTORE(); | |
575 | inflate_fast(strm, out); | |
576 | LOAD(); | |
577 | break; | |
578 | } | |
579 | for (;;) { | |
580 | this = state->lencode[BITS(state->lenbits)]; | |
581 | if ((unsigned)(this.bits) <= bits) break; | |
582 | PULLBYTE(); | |
583 | } | |
584 | if (this.op && (this.op & 0xf0) == 0) { | |
585 | last = this; | |
586 | for (;;) { | |
587 | this = state->lencode[last.val + | |
588 | (BITS(last.bits + last.op) >> last.bits)]; | |
589 | if ((unsigned)(last.bits + this.bits) <= bits) break; | |
590 | PULLBYTE(); | |
591 | } | |
592 | DROPBITS(last.bits); | |
593 | } | |
594 | DROPBITS(this.bits); | |
595 | state->length = (unsigned)this.val; | |
596 | if ((int)(this.op) == 0) { | |
597 | state->mode = LIT; | |
598 | break; | |
599 | } | |
600 | if (this.op & 32) { | |
601 | state->mode = TYPE; | |
602 | break; | |
603 | } | |
604 | if (this.op & 64) { | |
605 | strm->msg = (char *)"invalid literal/length code"; | |
606 | state->mode = BAD; | |
607 | break; | |
608 | } | |
609 | state->extra = (unsigned)(this.op) & 15; | |
610 | state->mode = LENEXT; | |
611 | case LENEXT: | |
612 | if (state->extra) { | |
613 | NEEDBITS(state->extra); | |
614 | state->length += BITS(state->extra); | |
615 | DROPBITS(state->extra); | |
616 | } | |
617 | state->mode = DIST; | |
618 | case DIST: | |
619 | for (;;) { | |
620 | this = state->distcode[BITS(state->distbits)]; | |
621 | if ((unsigned)(this.bits) <= bits) break; | |
622 | PULLBYTE(); | |
623 | } | |
624 | if ((this.op & 0xf0) == 0) { | |
625 | last = this; | |
626 | for (;;) { | |
627 | this = state->distcode[last.val + | |
628 | (BITS(last.bits + last.op) >> last.bits)]; | |
629 | if ((unsigned)(last.bits + this.bits) <= bits) break; | |
630 | PULLBYTE(); | |
631 | } | |
632 | DROPBITS(last.bits); | |
633 | } | |
634 | DROPBITS(this.bits); | |
635 | if (this.op & 64) { | |
636 | strm->msg = (char *)"invalid distance code"; | |
637 | state->mode = BAD; | |
638 | break; | |
639 | } | |
640 | state->offset = (unsigned)this.val; | |
641 | state->extra = (unsigned)(this.op) & 15; | |
642 | state->mode = DISTEXT; | |
643 | case DISTEXT: | |
644 | if (state->extra) { | |
645 | NEEDBITS(state->extra); | |
646 | state->offset += BITS(state->extra); | |
647 | DROPBITS(state->extra); | |
648 | } | |
649 | #ifdef INFLATE_STRICT | |
650 | if (state->offset > state->dmax) { | |
651 | strm->msg = (char *)"invalid distance too far back"; | |
652 | state->mode = BAD; | |
653 | break; | |
654 | } | |
655 | #endif | |
656 | if (state->offset > state->whave + out - left) { | |
657 | strm->msg = (char *)"invalid distance too far back"; | |
658 | state->mode = BAD; | |
659 | break; | |
660 | } | |
661 | state->mode = MATCH; | |
662 | case MATCH: | |
663 | if (left == 0) goto inf_leave; | |
664 | copy = out - left; | |
665 | if (state->offset > copy) { /* copy from window */ | |
666 | copy = state->offset - copy; | |
667 | if (copy > state->write) { | |
668 | copy -= state->write; | |
669 | from = state->window + (state->wsize - copy); | |
670 | } | |
671 | else | |
672 | from = state->window + (state->write - copy); | |
673 | if (copy > state->length) copy = state->length; | |
674 | } | |
675 | else { /* copy from output */ | |
676 | from = put - state->offset; | |
677 | copy = state->length; | |
678 | } | |
679 | if (copy > left) copy = left; | |
680 | left -= copy; | |
681 | state->length -= copy; | |
682 | do { | |
683 | *put++ = *from++; | |
684 | } while (--copy); | |
685 | if (state->length == 0) state->mode = LEN; | |
686 | break; | |
687 | case LIT: | |
688 | if (left == 0) goto inf_leave; | |
689 | *put++ = (unsigned char)(state->length); | |
690 | left--; | |
691 | state->mode = LEN; | |
692 | break; | |
693 | case CHECK: | |
694 | if (state->wrap) { | |
695 | NEEDBITS(32); | |
696 | out -= left; | |
697 | strm->total_out += out; | |
698 | state->total += out; | |
699 | if (out) | |
700 | strm->adler = state->check = | |
701 | UPDATE(state->check, put - out, out); | |
702 | out = left; | |
703 | if (( | |
704 | REVERSE(hold)) != state->check) { | |
705 | strm->msg = (char *)"incorrect data check"; | |
706 | state->mode = BAD; | |
707 | break; | |
708 | } | |
709 | INITBITS(); | |
710 | } | |
711 | state->mode = DONE; | |
712 | case DONE: | |
713 | ret = Z_STREAM_END; | |
714 | goto inf_leave; | |
715 | case BAD: | |
716 | ret = Z_DATA_ERROR; | |
717 | goto inf_leave; | |
718 | case MEM: | |
719 | return Z_MEM_ERROR; | |
720 | case SYNC: | |
721 | default: | |
722 | return Z_STREAM_ERROR; | |
723 | } | |
724 | ||
725 | /* | |
726 | Return from inflate(), updating the total counts and the check value. | |
727 | If there was no progress during the inflate() call, return a buffer | |
728 | error. Call zlib_updatewindow() to create and/or update the window state. | |
729 | */ | |
730 | inf_leave: | |
731 | RESTORE(); | |
732 | if (state->wsize || (state->mode < CHECK && out != strm->avail_out)) | |
733 | zlib_updatewindow(strm, out); | |
734 | ||
735 | in -= strm->avail_in; | |
736 | out -= strm->avail_out; | |
737 | strm->total_in += in; | |
738 | strm->total_out += out; | |
739 | state->total += out; | |
740 | if (state->wrap && out) | |
741 | strm->adler = state->check = | |
742 | UPDATE(state->check, strm->next_out - out, out); | |
743 | ||
744 | strm->data_type = state->bits + (state->last ? 64 : 0) + | |
745 | (state->mode == TYPE ? 128 : 0); | |
4f3865fb RP |
746 | |
747 | if (flush == Z_PACKET_FLUSH && ret == Z_OK && | |
f0ac6758 | 748 | strm->avail_out != 0 && strm->avail_in == 0) |
4f3865fb | 749 | return zlib_inflateSyncPacket(strm); |
f0ac6758 RP |
750 | |
751 | if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK) | |
752 | ret = Z_BUF_ERROR; | |
753 | ||
4f3865fb RP |
754 | return ret; |
755 | } | |
756 | ||
757 | int zlib_inflateEnd(z_streamp strm) | |
758 | { | |
759 | if (strm == NULL || strm->state == NULL) | |
760 | return Z_STREAM_ERROR; | |
1da177e4 LT |
761 | return Z_OK; |
762 | } | |
763 | ||
4f3865fb RP |
764 | #if 0 |
765 | int zlib_inflateSetDictionary(z_streamp strm, const Byte *dictionary, | |
766 | uInt dictLength) | |
767 | { | |
768 | struct inflate_state *state; | |
769 | unsigned long id; | |
770 | ||
771 | /* check state */ | |
772 | if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR; | |
773 | state = (struct inflate_state *)strm->state; | |
774 | if (state->wrap != 0 && state->mode != DICT) | |
775 | return Z_STREAM_ERROR; | |
776 | ||
777 | /* check for correct dictionary id */ | |
778 | if (state->mode == DICT) { | |
779 | id = zlib_adler32(0L, NULL, 0); | |
780 | id = zlib_adler32(id, dictionary, dictLength); | |
781 | if (id != state->check) | |
782 | return Z_DATA_ERROR; | |
783 | } | |
784 | ||
785 | /* copy dictionary to window */ | |
786 | zlib_updatewindow(strm, strm->avail_out); | |
1da177e4 | 787 | |
4f3865fb RP |
788 | if (dictLength > state->wsize) { |
789 | memcpy(state->window, dictionary + dictLength - state->wsize, | |
790 | state->wsize); | |
791 | state->whave = state->wsize; | |
792 | } | |
793 | else { | |
794 | memcpy(state->window + state->wsize - dictLength, dictionary, | |
795 | dictLength); | |
796 | state->whave = dictLength; | |
797 | } | |
798 | state->havedict = 1; | |
799 | return Z_OK; | |
800 | } | |
801 | #endif | |
802 | ||
803 | #if 0 | |
804 | /* | |
805 | Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found | |
806 | or when out of input. When called, *have is the number of pattern bytes | |
807 | found in order so far, in 0..3. On return *have is updated to the new | |
808 | state. If on return *have equals four, then the pattern was found and the | |
809 | return value is how many bytes were read including the last byte of the | |
810 | pattern. If *have is less than four, then the pattern has not been found | |
811 | yet and the return value is len. In the latter case, zlib_syncsearch() can be | |
812 | called again with more data and the *have state. *have is initialized to | |
813 | zero for the first call. | |
814 | */ | |
815 | static unsigned zlib_syncsearch(unsigned *have, unsigned char *buf, | |
816 | unsigned len) | |
1da177e4 | 817 | { |
4f3865fb RP |
818 | unsigned got; |
819 | unsigned next; | |
820 | ||
821 | got = *have; | |
822 | next = 0; | |
823 | while (next < len && got < 4) { | |
824 | if ((int)(buf[next]) == (got < 2 ? 0 : 0xff)) | |
825 | got++; | |
826 | else if (buf[next]) | |
827 | got = 0; | |
828 | else | |
829 | got = 4 - got; | |
830 | next++; | |
831 | } | |
832 | *have = got; | |
833 | return next; | |
1da177e4 | 834 | } |
4f3865fb | 835 | #endif |
1da177e4 | 836 | |
4f3865fb RP |
837 | #if 0 |
838 | int zlib_inflateSync(z_streamp strm) | |
839 | { | |
840 | unsigned len; /* number of bytes to look at or looked at */ | |
841 | unsigned long in, out; /* temporary to save total_in and total_out */ | |
842 | unsigned char buf[4]; /* to restore bit buffer to byte string */ | |
843 | struct inflate_state *state; | |
844 | ||
845 | /* check parameters */ | |
846 | if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR; | |
847 | state = (struct inflate_state *)strm->state; | |
848 | if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR; | |
849 | ||
850 | /* if first time, start search in bit buffer */ | |
851 | if (state->mode != SYNC) { | |
852 | state->mode = SYNC; | |
853 | state->hold <<= state->bits & 7; | |
854 | state->bits -= state->bits & 7; | |
855 | len = 0; | |
856 | while (state->bits >= 8) { | |
857 | buf[len++] = (unsigned char)(state->hold); | |
858 | state->hold >>= 8; | |
859 | state->bits -= 8; | |
860 | } | |
861 | state->have = 0; | |
862 | zlib_syncsearch(&(state->have), buf, len); | |
863 | } | |
864 | ||
865 | /* search available input */ | |
866 | len = zlib_syncsearch(&(state->have), strm->next_in, strm->avail_in); | |
867 | strm->avail_in -= len; | |
868 | strm->next_in += len; | |
869 | strm->total_in += len; | |
870 | ||
871 | /* return no joy or set up to restart inflate() on a new block */ | |
872 | if (state->have != 4) return Z_DATA_ERROR; | |
873 | in = strm->total_in; out = strm->total_out; | |
874 | zlib_inflateReset(strm); | |
875 | strm->total_in = in; strm->total_out = out; | |
876 | state->mode = TYPE; | |
877 | return Z_OK; | |
878 | } | |
879 | #endif | |
1da177e4 | 880 | |
4f3865fb RP |
881 | /* |
882 | * This subroutine adds the data at next_in/avail_in to the output history | |
883 | * without performing any output. The output buffer must be "caught up"; | |
884 | * i.e. no pending output but this should always be the case. The state must | |
885 | * be waiting on the start of a block (i.e. mode == TYPE or HEAD). On exit, | |
886 | * the output will also be caught up, and the checksum will have been updated | |
887 | * if need be. | |
888 | */ | |
889 | int zlib_inflateIncomp(z_stream *z) | |
1da177e4 | 890 | { |
4f3865fb RP |
891 | struct inflate_state *state = (struct inflate_state *)z->state; |
892 | Byte *saved_no = z->next_out; | |
893 | uInt saved_ao = z->avail_out; | |
894 | ||
895 | if (state->mode != TYPE && state->mode != HEAD) | |
896 | return Z_DATA_ERROR; | |
897 | ||
898 | /* Setup some variables to allow misuse of updateWindow */ | |
899 | z->avail_out = 0; | |
8336793b | 900 | z->next_out = (unsigned char*)z->next_in + z->avail_in; |
4f3865fb RP |
901 | |
902 | zlib_updatewindow(z, z->avail_in); | |
903 | ||
904 | /* Restore saved variables */ | |
905 | z->avail_out = saved_ao; | |
906 | z->next_out = saved_no; | |
907 | ||
908 | z->adler = state->check = | |
909 | UPDATE(state->check, z->next_in, z->avail_in); | |
910 | ||
911 | z->total_out += z->avail_in; | |
912 | z->total_in += z->avail_in; | |
913 | z->next_in += z->avail_in; | |
914 | state->total += z->avail_in; | |
915 | z->avail_in = 0; | |
916 | ||
917 | return Z_OK; | |
1da177e4 | 918 | } |