Mercurial > repos > blastem
comparison zlib/inflate.c @ 1648:b7ecd0d6a77b mame_interp
Merge from default
author | Michael Pavone <pavone@retrodev.com> |
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date | Tue, 25 Dec 2018 11:12:26 -0800 |
parents | 00d788dac91a |
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1509:36732f5c2281 | 1648:b7ecd0d6a77b |
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1 /* inflate.c -- zlib decompression | |
2 * Copyright (C) 1995-2016 Mark Adler | |
3 * For conditions of distribution and use, see copyright notice in zlib.h | |
4 */ | |
5 | |
6 /* | |
7 * Change history: | |
8 * | |
9 * 1.2.beta0 24 Nov 2002 | |
10 * - First version -- complete rewrite of inflate to simplify code, avoid | |
11 * creation of window when not needed, minimize use of window when it is | |
12 * needed, make inffast.c even faster, implement gzip decoding, and to | |
13 * improve code readability and style over the previous zlib inflate code | |
14 * | |
15 * 1.2.beta1 25 Nov 2002 | |
16 * - Use pointers for available input and output checking in inffast.c | |
17 * - Remove input and output counters in inffast.c | |
18 * - Change inffast.c entry and loop from avail_in >= 7 to >= 6 | |
19 * - Remove unnecessary second byte pull from length extra in inffast.c | |
20 * - Unroll direct copy to three copies per loop in inffast.c | |
21 * | |
22 * 1.2.beta2 4 Dec 2002 | |
23 * - Change external routine names to reduce potential conflicts | |
24 * - Correct filename to inffixed.h for fixed tables in inflate.c | |
25 * - Make hbuf[] unsigned char to match parameter type in inflate.c | |
26 * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset) | |
27 * to avoid negation problem on Alphas (64 bit) in inflate.c | |
28 * | |
29 * 1.2.beta3 22 Dec 2002 | |
30 * - Add comments on state->bits assertion in inffast.c | |
31 * - Add comments on op field in inftrees.h | |
32 * - Fix bug in reuse of allocated window after inflateReset() | |
33 * - Remove bit fields--back to byte structure for speed | |
34 * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths | |
35 * - Change post-increments to pre-increments in inflate_fast(), PPC biased? | |
36 * - Add compile time option, POSTINC, to use post-increments instead (Intel?) | |
37 * - Make MATCH copy in inflate() much faster for when inflate_fast() not used | |
38 * - Use local copies of stream next and avail values, as well as local bit | |
39 * buffer and bit count in inflate()--for speed when inflate_fast() not used | |
40 * | |
41 * 1.2.beta4 1 Jan 2003 | |
42 * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings | |
43 * - Move a comment on output buffer sizes from inffast.c to inflate.c | |
44 * - Add comments in inffast.c to introduce the inflate_fast() routine | |
45 * - Rearrange window copies in inflate_fast() for speed and simplification | |
46 * - Unroll last copy for window match in inflate_fast() | |
47 * - Use local copies of window variables in inflate_fast() for speed | |
48 * - Pull out common wnext == 0 case for speed in inflate_fast() | |
49 * - Make op and len in inflate_fast() unsigned for consistency | |
50 * - Add FAR to lcode and dcode declarations in inflate_fast() | |
51 * - Simplified bad distance check in inflate_fast() | |
52 * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new | |
53 * source file infback.c to provide a call-back interface to inflate for | |
54 * programs like gzip and unzip -- uses window as output buffer to avoid | |
55 * window copying | |
56 * | |
57 * 1.2.beta5 1 Jan 2003 | |
58 * - Improved inflateBack() interface to allow the caller to provide initial | |
59 * input in strm. | |
60 * - Fixed stored blocks bug in inflateBack() | |
61 * | |
62 * 1.2.beta6 4 Jan 2003 | |
63 * - Added comments in inffast.c on effectiveness of POSTINC | |
64 * - Typecasting all around to reduce compiler warnings | |
65 * - Changed loops from while (1) or do {} while (1) to for (;;), again to | |
66 * make compilers happy | |
67 * - Changed type of window in inflateBackInit() to unsigned char * | |
68 * | |
69 * 1.2.beta7 27 Jan 2003 | |
70 * - Changed many types to unsigned or unsigned short to avoid warnings | |
71 * - Added inflateCopy() function | |
72 * | |
73 * 1.2.0 9 Mar 2003 | |
74 * - Changed inflateBack() interface to provide separate opaque descriptors | |
75 * for the in() and out() functions | |
76 * - Changed inflateBack() argument and in_func typedef to swap the length | |
77 * and buffer address return values for the input function | |
78 * - Check next_in and next_out for Z_NULL on entry to inflate() | |
79 * | |
80 * The history for versions after 1.2.0 are in ChangeLog in zlib distribution. | |
81 */ | |
82 | |
83 #include "zutil.h" | |
84 #include "inftrees.h" | |
85 #include "inflate.h" | |
86 #include "inffast.h" | |
87 | |
88 #ifdef MAKEFIXED | |
89 # ifndef BUILDFIXED | |
90 # define BUILDFIXED | |
91 # endif | |
92 #endif | |
93 | |
94 /* function prototypes */ | |
95 local int inflateStateCheck OF((z_streamp strm)); | |
96 local void fixedtables OF((struct inflate_state FAR *state)); | |
97 local int updatewindow OF((z_streamp strm, const unsigned char FAR *end, | |
98 unsigned copy)); | |
99 #ifdef BUILDFIXED | |
100 void makefixed OF((void)); | |
101 #endif | |
102 local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf, | |
103 unsigned len)); | |
104 | |
105 local int inflateStateCheck(strm) | |
106 z_streamp strm; | |
107 { | |
108 struct inflate_state FAR *state; | |
109 if (strm == Z_NULL || | |
110 strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) | |
111 return 1; | |
112 state = (struct inflate_state FAR *)strm->state; | |
113 if (state == Z_NULL || state->strm != strm || | |
114 state->mode < HEAD || state->mode > SYNC) | |
115 return 1; | |
116 return 0; | |
117 } | |
118 | |
119 int ZEXPORT inflateResetKeep(strm) | |
120 z_streamp strm; | |
121 { | |
122 struct inflate_state FAR *state; | |
123 | |
124 if (inflateStateCheck(strm)) return Z_STREAM_ERROR; | |
125 state = (struct inflate_state FAR *)strm->state; | |
126 strm->total_in = strm->total_out = state->total = 0; | |
127 strm->msg = Z_NULL; | |
128 if (state->wrap) /* to support ill-conceived Java test suite */ | |
129 strm->adler = state->wrap & 1; | |
130 state->mode = HEAD; | |
131 state->last = 0; | |
132 state->havedict = 0; | |
133 state->dmax = 32768U; | |
134 state->head = Z_NULL; | |
135 state->hold = 0; | |
136 state->bits = 0; | |
137 state->lencode = state->distcode = state->next = state->codes; | |
138 state->sane = 1; | |
139 state->back = -1; | |
140 Tracev((stderr, "inflate: reset\n")); | |
141 return Z_OK; | |
142 } | |
143 | |
144 int ZEXPORT inflateReset(strm) | |
145 z_streamp strm; | |
146 { | |
147 struct inflate_state FAR *state; | |
148 | |
149 if (inflateStateCheck(strm)) return Z_STREAM_ERROR; | |
150 state = (struct inflate_state FAR *)strm->state; | |
151 state->wsize = 0; | |
152 state->whave = 0; | |
153 state->wnext = 0; | |
154 return inflateResetKeep(strm); | |
155 } | |
156 | |
157 int ZEXPORT inflateReset2(strm, windowBits) | |
158 z_streamp strm; | |
159 int windowBits; | |
160 { | |
161 int wrap; | |
162 struct inflate_state FAR *state; | |
163 | |
164 /* get the state */ | |
165 if (inflateStateCheck(strm)) return Z_STREAM_ERROR; | |
166 state = (struct inflate_state FAR *)strm->state; | |
167 | |
168 /* extract wrap request from windowBits parameter */ | |
169 if (windowBits < 0) { | |
170 wrap = 0; | |
171 windowBits = -windowBits; | |
172 } | |
173 else { | |
174 wrap = (windowBits >> 4) + 5; | |
175 #ifdef GUNZIP | |
176 if (windowBits < 48) | |
177 windowBits &= 15; | |
178 #endif | |
179 } | |
180 | |
181 /* set number of window bits, free window if different */ | |
182 if (windowBits && (windowBits < 8 || windowBits > 15)) | |
183 return Z_STREAM_ERROR; | |
184 if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) { | |
185 ZFREE(strm, state->window); | |
186 state->window = Z_NULL; | |
187 } | |
188 | |
189 /* update state and reset the rest of it */ | |
190 state->wrap = wrap; | |
191 state->wbits = (unsigned)windowBits; | |
192 return inflateReset(strm); | |
193 } | |
194 | |
195 int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size) | |
196 z_streamp strm; | |
197 int windowBits; | |
198 const char *version; | |
199 int stream_size; | |
200 { | |
201 int ret; | |
202 struct inflate_state FAR *state; | |
203 | |
204 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || | |
205 stream_size != (int)(sizeof(z_stream))) | |
206 return Z_VERSION_ERROR; | |
207 if (strm == Z_NULL) return Z_STREAM_ERROR; | |
208 strm->msg = Z_NULL; /* in case we return an error */ | |
209 if (strm->zalloc == (alloc_func)0) { | |
210 #ifdef Z_SOLO | |
211 return Z_STREAM_ERROR; | |
212 #else | |
213 strm->zalloc = zcalloc; | |
214 strm->opaque = (voidpf)0; | |
215 #endif | |
216 } | |
217 if (strm->zfree == (free_func)0) | |
218 #ifdef Z_SOLO | |
219 return Z_STREAM_ERROR; | |
220 #else | |
221 strm->zfree = zcfree; | |
222 #endif | |
223 state = (struct inflate_state FAR *) | |
224 ZALLOC(strm, 1, sizeof(struct inflate_state)); | |
225 if (state == Z_NULL) return Z_MEM_ERROR; | |
226 Tracev((stderr, "inflate: allocated\n")); | |
227 strm->state = (struct internal_state FAR *)state; | |
228 state->strm = strm; | |
229 state->window = Z_NULL; | |
230 state->mode = HEAD; /* to pass state test in inflateReset2() */ | |
231 ret = inflateReset2(strm, windowBits); | |
232 if (ret != Z_OK) { | |
233 ZFREE(strm, state); | |
234 strm->state = Z_NULL; | |
235 } | |
236 return ret; | |
237 } | |
238 | |
239 int ZEXPORT inflateInit_(strm, version, stream_size) | |
240 z_streamp strm; | |
241 const char *version; | |
242 int stream_size; | |
243 { | |
244 return inflateInit2_(strm, DEF_WBITS, version, stream_size); | |
245 } | |
246 | |
247 int ZEXPORT inflatePrime(strm, bits, value) | |
248 z_streamp strm; | |
249 int bits; | |
250 int value; | |
251 { | |
252 struct inflate_state FAR *state; | |
253 | |
254 if (inflateStateCheck(strm)) return Z_STREAM_ERROR; | |
255 state = (struct inflate_state FAR *)strm->state; | |
256 if (bits < 0) { | |
257 state->hold = 0; | |
258 state->bits = 0; | |
259 return Z_OK; | |
260 } | |
261 if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR; | |
262 value &= (1L << bits) - 1; | |
263 state->hold += (unsigned)value << state->bits; | |
264 state->bits += (uInt)bits; | |
265 return Z_OK; | |
266 } | |
267 | |
268 /* | |
269 Return state with length and distance decoding tables and index sizes set to | |
270 fixed code decoding. Normally this returns fixed tables from inffixed.h. | |
271 If BUILDFIXED is defined, then instead this routine builds the tables the | |
272 first time it's called, and returns those tables the first time and | |
273 thereafter. This reduces the size of the code by about 2K bytes, in | |
274 exchange for a little execution time. However, BUILDFIXED should not be | |
275 used for threaded applications, since the rewriting of the tables and virgin | |
276 may not be thread-safe. | |
277 */ | |
278 local void fixedtables(state) | |
279 struct inflate_state FAR *state; | |
280 { | |
281 #ifdef BUILDFIXED | |
282 static int virgin = 1; | |
283 static code *lenfix, *distfix; | |
284 static code fixed[544]; | |
285 | |
286 /* build fixed huffman tables if first call (may not be thread safe) */ | |
287 if (virgin) { | |
288 unsigned sym, bits; | |
289 static code *next; | |
290 | |
291 /* literal/length table */ | |
292 sym = 0; | |
293 while (sym < 144) state->lens[sym++] = 8; | |
294 while (sym < 256) state->lens[sym++] = 9; | |
295 while (sym < 280) state->lens[sym++] = 7; | |
296 while (sym < 288) state->lens[sym++] = 8; | |
297 next = fixed; | |
298 lenfix = next; | |
299 bits = 9; | |
300 inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work); | |
301 | |
302 /* distance table */ | |
303 sym = 0; | |
304 while (sym < 32) state->lens[sym++] = 5; | |
305 distfix = next; | |
306 bits = 5; | |
307 inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work); | |
308 | |
309 /* do this just once */ | |
310 virgin = 0; | |
311 } | |
312 #else /* !BUILDFIXED */ | |
313 # include "inffixed.h" | |
314 #endif /* BUILDFIXED */ | |
315 state->lencode = lenfix; | |
316 state->lenbits = 9; | |
317 state->distcode = distfix; | |
318 state->distbits = 5; | |
319 } | |
320 | |
321 #ifdef MAKEFIXED | |
322 #include <stdio.h> | |
323 | |
324 /* | |
325 Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also | |
326 defines BUILDFIXED, so the tables are built on the fly. makefixed() writes | |
327 those tables to stdout, which would be piped to inffixed.h. A small program | |
328 can simply call makefixed to do this: | |
329 | |
330 void makefixed(void); | |
331 | |
332 int main(void) | |
333 { | |
334 makefixed(); | |
335 return 0; | |
336 } | |
337 | |
338 Then that can be linked with zlib built with MAKEFIXED defined and run: | |
339 | |
340 a.out > inffixed.h | |
341 */ | |
342 void makefixed() | |
343 { | |
344 unsigned low, size; | |
345 struct inflate_state state; | |
346 | |
347 fixedtables(&state); | |
348 puts(" /* inffixed.h -- table for decoding fixed codes"); | |
349 puts(" * Generated automatically by makefixed()."); | |
350 puts(" */"); | |
351 puts(""); | |
352 puts(" /* WARNING: this file should *not* be used by applications."); | |
353 puts(" It is part of the implementation of this library and is"); | |
354 puts(" subject to change. Applications should only use zlib.h."); | |
355 puts(" */"); | |
356 puts(""); | |
357 size = 1U << 9; | |
358 printf(" static const code lenfix[%u] = {", size); | |
359 low = 0; | |
360 for (;;) { | |
361 if ((low % 7) == 0) printf("\n "); | |
362 printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op, | |
363 state.lencode[low].bits, state.lencode[low].val); | |
364 if (++low == size) break; | |
365 putchar(','); | |
366 } | |
367 puts("\n };"); | |
368 size = 1U << 5; | |
369 printf("\n static const code distfix[%u] = {", size); | |
370 low = 0; | |
371 for (;;) { | |
372 if ((low % 6) == 0) printf("\n "); | |
373 printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits, | |
374 state.distcode[low].val); | |
375 if (++low == size) break; | |
376 putchar(','); | |
377 } | |
378 puts("\n };"); | |
379 } | |
380 #endif /* MAKEFIXED */ | |
381 | |
382 /* | |
383 Update the window with the last wsize (normally 32K) bytes written before | |
384 returning. If window does not exist yet, create it. This is only called | |
385 when a window is already in use, or when output has been written during this | |
386 inflate call, but the end of the deflate stream has not been reached yet. | |
387 It is also called to create a window for dictionary data when a dictionary | |
388 is loaded. | |
389 | |
390 Providing output buffers larger than 32K to inflate() should provide a speed | |
391 advantage, since only the last 32K of output is copied to the sliding window | |
392 upon return from inflate(), and since all distances after the first 32K of | |
393 output will fall in the output data, making match copies simpler and faster. | |
394 The advantage may be dependent on the size of the processor's data caches. | |
395 */ | |
396 local int updatewindow(strm, end, copy) | |
397 z_streamp strm; | |
398 const Bytef *end; | |
399 unsigned copy; | |
400 { | |
401 struct inflate_state FAR *state; | |
402 unsigned dist; | |
403 | |
404 state = (struct inflate_state FAR *)strm->state; | |
405 | |
406 /* if it hasn't been done already, allocate space for the window */ | |
407 if (state->window == Z_NULL) { | |
408 state->window = (unsigned char FAR *) | |
409 ZALLOC(strm, 1U << state->wbits, | |
410 sizeof(unsigned char)); | |
411 if (state->window == Z_NULL) return 1; | |
412 } | |
413 | |
414 /* if window not in use yet, initialize */ | |
415 if (state->wsize == 0) { | |
416 state->wsize = 1U << state->wbits; | |
417 state->wnext = 0; | |
418 state->whave = 0; | |
419 } | |
420 | |
421 /* copy state->wsize or less output bytes into the circular window */ | |
422 if (copy >= state->wsize) { | |
423 zmemcpy(state->window, end - state->wsize, state->wsize); | |
424 state->wnext = 0; | |
425 state->whave = state->wsize; | |
426 } | |
427 else { | |
428 dist = state->wsize - state->wnext; | |
429 if (dist > copy) dist = copy; | |
430 zmemcpy(state->window + state->wnext, end - copy, dist); | |
431 copy -= dist; | |
432 if (copy) { | |
433 zmemcpy(state->window, end - copy, copy); | |
434 state->wnext = copy; | |
435 state->whave = state->wsize; | |
436 } | |
437 else { | |
438 state->wnext += dist; | |
439 if (state->wnext == state->wsize) state->wnext = 0; | |
440 if (state->whave < state->wsize) state->whave += dist; | |
441 } | |
442 } | |
443 return 0; | |
444 } | |
445 | |
446 /* Macros for inflate(): */ | |
447 | |
448 /* check function to use adler32() for zlib or crc32() for gzip */ | |
449 #ifdef GUNZIP | |
450 # define UPDATE(check, buf, len) \ | |
451 (state->flags ? crc32(check, buf, len) : adler32(check, buf, len)) | |
452 #else | |
453 # define UPDATE(check, buf, len) adler32(check, buf, len) | |
454 #endif | |
455 | |
456 /* check macros for header crc */ | |
457 #ifdef GUNZIP | |
458 # define CRC2(check, word) \ | |
459 do { \ | |
460 hbuf[0] = (unsigned char)(word); \ | |
461 hbuf[1] = (unsigned char)((word) >> 8); \ | |
462 check = crc32(check, hbuf, 2); \ | |
463 } while (0) | |
464 | |
465 # define CRC4(check, word) \ | |
466 do { \ | |
467 hbuf[0] = (unsigned char)(word); \ | |
468 hbuf[1] = (unsigned char)((word) >> 8); \ | |
469 hbuf[2] = (unsigned char)((word) >> 16); \ | |
470 hbuf[3] = (unsigned char)((word) >> 24); \ | |
471 check = crc32(check, hbuf, 4); \ | |
472 } while (0) | |
473 #endif | |
474 | |
475 /* Load registers with state in inflate() for speed */ | |
476 #define LOAD() \ | |
477 do { \ | |
478 put = strm->next_out; \ | |
479 left = strm->avail_out; \ | |
480 next = strm->next_in; \ | |
481 have = strm->avail_in; \ | |
482 hold = state->hold; \ | |
483 bits = state->bits; \ | |
484 } while (0) | |
485 | |
486 /* Restore state from registers in inflate() */ | |
487 #define RESTORE() \ | |
488 do { \ | |
489 strm->next_out = put; \ | |
490 strm->avail_out = left; \ | |
491 strm->next_in = next; \ | |
492 strm->avail_in = have; \ | |
493 state->hold = hold; \ | |
494 state->bits = bits; \ | |
495 } while (0) | |
496 | |
497 /* Clear the input bit accumulator */ | |
498 #define INITBITS() \ | |
499 do { \ | |
500 hold = 0; \ | |
501 bits = 0; \ | |
502 } while (0) | |
503 | |
504 /* Get a byte of input into the bit accumulator, or return from inflate() | |
505 if there is no input available. */ | |
506 #define PULLBYTE() \ | |
507 do { \ | |
508 if (have == 0) goto inf_leave; \ | |
509 have--; \ | |
510 hold += (unsigned long)(*next++) << bits; \ | |
511 bits += 8; \ | |
512 } while (0) | |
513 | |
514 /* Assure that there are at least n bits in the bit accumulator. If there is | |
515 not enough available input to do that, then return from inflate(). */ | |
516 #define NEEDBITS(n) \ | |
517 do { \ | |
518 while (bits < (unsigned)(n)) \ | |
519 PULLBYTE(); \ | |
520 } while (0) | |
521 | |
522 /* Return the low n bits of the bit accumulator (n < 16) */ | |
523 #define BITS(n) \ | |
524 ((unsigned)hold & ((1U << (n)) - 1)) | |
525 | |
526 /* Remove n bits from the bit accumulator */ | |
527 #define DROPBITS(n) \ | |
528 do { \ | |
529 hold >>= (n); \ | |
530 bits -= (unsigned)(n); \ | |
531 } while (0) | |
532 | |
533 /* Remove zero to seven bits as needed to go to a byte boundary */ | |
534 #define BYTEBITS() \ | |
535 do { \ | |
536 hold >>= bits & 7; \ | |
537 bits -= bits & 7; \ | |
538 } while (0) | |
539 | |
540 /* | |
541 inflate() uses a state machine to process as much input data and generate as | |
542 much output data as possible before returning. The state machine is | |
543 structured roughly as follows: | |
544 | |
545 for (;;) switch (state) { | |
546 ... | |
547 case STATEn: | |
548 if (not enough input data or output space to make progress) | |
549 return; | |
550 ... make progress ... | |
551 state = STATEm; | |
552 break; | |
553 ... | |
554 } | |
555 | |
556 so when inflate() is called again, the same case is attempted again, and | |
557 if the appropriate resources are provided, the machine proceeds to the | |
558 next state. The NEEDBITS() macro is usually the way the state evaluates | |
559 whether it can proceed or should return. NEEDBITS() does the return if | |
560 the requested bits are not available. The typical use of the BITS macros | |
561 is: | |
562 | |
563 NEEDBITS(n); | |
564 ... do something with BITS(n) ... | |
565 DROPBITS(n); | |
566 | |
567 where NEEDBITS(n) either returns from inflate() if there isn't enough | |
568 input left to load n bits into the accumulator, or it continues. BITS(n) | |
569 gives the low n bits in the accumulator. When done, DROPBITS(n) drops | |
570 the low n bits off the accumulator. INITBITS() clears the accumulator | |
571 and sets the number of available bits to zero. BYTEBITS() discards just | |
572 enough bits to put the accumulator on a byte boundary. After BYTEBITS() | |
573 and a NEEDBITS(8), then BITS(8) would return the next byte in the stream. | |
574 | |
575 NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return | |
576 if there is no input available. The decoding of variable length codes uses | |
577 PULLBYTE() directly in order to pull just enough bytes to decode the next | |
578 code, and no more. | |
579 | |
580 Some states loop until they get enough input, making sure that enough | |
581 state information is maintained to continue the loop where it left off | |
582 if NEEDBITS() returns in the loop. For example, want, need, and keep | |
583 would all have to actually be part of the saved state in case NEEDBITS() | |
584 returns: | |
585 | |
586 case STATEw: | |
587 while (want < need) { | |
588 NEEDBITS(n); | |
589 keep[want++] = BITS(n); | |
590 DROPBITS(n); | |
591 } | |
592 state = STATEx; | |
593 case STATEx: | |
594 | |
595 As shown above, if the next state is also the next case, then the break | |
596 is omitted. | |
597 | |
598 A state may also return if there is not enough output space available to | |
599 complete that state. Those states are copying stored data, writing a | |
600 literal byte, and copying a matching string. | |
601 | |
602 When returning, a "goto inf_leave" is used to update the total counters, | |
603 update the check value, and determine whether any progress has been made | |
604 during that inflate() call in order to return the proper return code. | |
605 Progress is defined as a change in either strm->avail_in or strm->avail_out. | |
606 When there is a window, goto inf_leave will update the window with the last | |
607 output written. If a goto inf_leave occurs in the middle of decompression | |
608 and there is no window currently, goto inf_leave will create one and copy | |
609 output to the window for the next call of inflate(). | |
610 | |
611 In this implementation, the flush parameter of inflate() only affects the | |
612 return code (per zlib.h). inflate() always writes as much as possible to | |
613 strm->next_out, given the space available and the provided input--the effect | |
614 documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers | |
615 the allocation of and copying into a sliding window until necessary, which | |
616 provides the effect documented in zlib.h for Z_FINISH when the entire input | |
617 stream available. So the only thing the flush parameter actually does is: | |
618 when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it | |
619 will return Z_BUF_ERROR if it has not reached the end of the stream. | |
620 */ | |
621 | |
622 int ZEXPORT inflate(strm, flush) | |
623 z_streamp strm; | |
624 int flush; | |
625 { | |
626 struct inflate_state FAR *state; | |
627 z_const unsigned char FAR *next; /* next input */ | |
628 unsigned char FAR *put; /* next output */ | |
629 unsigned have, left; /* available input and output */ | |
630 unsigned long hold; /* bit buffer */ | |
631 unsigned bits; /* bits in bit buffer */ | |
632 unsigned in, out; /* save starting available input and output */ | |
633 unsigned copy; /* number of stored or match bytes to copy */ | |
634 unsigned char FAR *from; /* where to copy match bytes from */ | |
635 code here; /* current decoding table entry */ | |
636 code last; /* parent table entry */ | |
637 unsigned len; /* length to copy for repeats, bits to drop */ | |
638 int ret; /* return code */ | |
639 #ifdef GUNZIP | |
640 unsigned char hbuf[4]; /* buffer for gzip header crc calculation */ | |
641 #endif | |
642 static const unsigned short order[19] = /* permutation of code lengths */ | |
643 {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; | |
644 | |
645 if (inflateStateCheck(strm) || strm->next_out == Z_NULL || | |
646 (strm->next_in == Z_NULL && strm->avail_in != 0)) | |
647 return Z_STREAM_ERROR; | |
648 | |
649 state = (struct inflate_state FAR *)strm->state; | |
650 if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */ | |
651 LOAD(); | |
652 in = have; | |
653 out = left; | |
654 ret = Z_OK; | |
655 for (;;) | |
656 switch (state->mode) { | |
657 case HEAD: | |
658 if (state->wrap == 0) { | |
659 state->mode = TYPEDO; | |
660 break; | |
661 } | |
662 NEEDBITS(16); | |
663 #ifdef GUNZIP | |
664 if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */ | |
665 if (state->wbits == 0) | |
666 state->wbits = 15; | |
667 state->check = crc32(0L, Z_NULL, 0); | |
668 CRC2(state->check, hold); | |
669 INITBITS(); | |
670 state->mode = FLAGS; | |
671 break; | |
672 } | |
673 state->flags = 0; /* expect zlib header */ | |
674 if (state->head != Z_NULL) | |
675 state->head->done = -1; | |
676 if (!(state->wrap & 1) || /* check if zlib header allowed */ | |
677 #else | |
678 if ( | |
679 #endif | |
680 ((BITS(8) << 8) + (hold >> 8)) % 31) { | |
681 strm->msg = (char *)"incorrect header check"; | |
682 state->mode = BAD; | |
683 break; | |
684 } | |
685 if (BITS(4) != Z_DEFLATED) { | |
686 strm->msg = (char *)"unknown compression method"; | |
687 state->mode = BAD; | |
688 break; | |
689 } | |
690 DROPBITS(4); | |
691 len = BITS(4) + 8; | |
692 if (state->wbits == 0) | |
693 state->wbits = len; | |
694 if (len > 15 || len > state->wbits) { | |
695 strm->msg = (char *)"invalid window size"; | |
696 state->mode = BAD; | |
697 break; | |
698 } | |
699 state->dmax = 1U << len; | |
700 Tracev((stderr, "inflate: zlib header ok\n")); | |
701 strm->adler = state->check = adler32(0L, Z_NULL, 0); | |
702 state->mode = hold & 0x200 ? DICTID : TYPE; | |
703 INITBITS(); | |
704 break; | |
705 #ifdef GUNZIP | |
706 case FLAGS: | |
707 NEEDBITS(16); | |
708 state->flags = (int)(hold); | |
709 if ((state->flags & 0xff) != Z_DEFLATED) { | |
710 strm->msg = (char *)"unknown compression method"; | |
711 state->mode = BAD; | |
712 break; | |
713 } | |
714 if (state->flags & 0xe000) { | |
715 strm->msg = (char *)"unknown header flags set"; | |
716 state->mode = BAD; | |
717 break; | |
718 } | |
719 if (state->head != Z_NULL) | |
720 state->head->text = (int)((hold >> 8) & 1); | |
721 if ((state->flags & 0x0200) && (state->wrap & 4)) | |
722 CRC2(state->check, hold); | |
723 INITBITS(); | |
724 state->mode = TIME; | |
725 case TIME: | |
726 NEEDBITS(32); | |
727 if (state->head != Z_NULL) | |
728 state->head->time = hold; | |
729 if ((state->flags & 0x0200) && (state->wrap & 4)) | |
730 CRC4(state->check, hold); | |
731 INITBITS(); | |
732 state->mode = OS; | |
733 case OS: | |
734 NEEDBITS(16); | |
735 if (state->head != Z_NULL) { | |
736 state->head->xflags = (int)(hold & 0xff); | |
737 state->head->os = (int)(hold >> 8); | |
738 } | |
739 if ((state->flags & 0x0200) && (state->wrap & 4)) | |
740 CRC2(state->check, hold); | |
741 INITBITS(); | |
742 state->mode = EXLEN; | |
743 case EXLEN: | |
744 if (state->flags & 0x0400) { | |
745 NEEDBITS(16); | |
746 state->length = (unsigned)(hold); | |
747 if (state->head != Z_NULL) | |
748 state->head->extra_len = (unsigned)hold; | |
749 if ((state->flags & 0x0200) && (state->wrap & 4)) | |
750 CRC2(state->check, hold); | |
751 INITBITS(); | |
752 } | |
753 else if (state->head != Z_NULL) | |
754 state->head->extra = Z_NULL; | |
755 state->mode = EXTRA; | |
756 case EXTRA: | |
757 if (state->flags & 0x0400) { | |
758 copy = state->length; | |
759 if (copy > have) copy = have; | |
760 if (copy) { | |
761 if (state->head != Z_NULL && | |
762 state->head->extra != Z_NULL) { | |
763 len = state->head->extra_len - state->length; | |
764 zmemcpy(state->head->extra + len, next, | |
765 len + copy > state->head->extra_max ? | |
766 state->head->extra_max - len : copy); | |
767 } | |
768 if ((state->flags & 0x0200) && (state->wrap & 4)) | |
769 state->check = crc32(state->check, next, copy); | |
770 have -= copy; | |
771 next += copy; | |
772 state->length -= copy; | |
773 } | |
774 if (state->length) goto inf_leave; | |
775 } | |
776 state->length = 0; | |
777 state->mode = NAME; | |
778 case NAME: | |
779 if (state->flags & 0x0800) { | |
780 if (have == 0) goto inf_leave; | |
781 copy = 0; | |
782 do { | |
783 len = (unsigned)(next[copy++]); | |
784 if (state->head != Z_NULL && | |
785 state->head->name != Z_NULL && | |
786 state->length < state->head->name_max) | |
787 state->head->name[state->length++] = (Bytef)len; | |
788 } while (len && copy < have); | |
789 if ((state->flags & 0x0200) && (state->wrap & 4)) | |
790 state->check = crc32(state->check, next, copy); | |
791 have -= copy; | |
792 next += copy; | |
793 if (len) goto inf_leave; | |
794 } | |
795 else if (state->head != Z_NULL) | |
796 state->head->name = Z_NULL; | |
797 state->length = 0; | |
798 state->mode = COMMENT; | |
799 case COMMENT: | |
800 if (state->flags & 0x1000) { | |
801 if (have == 0) goto inf_leave; | |
802 copy = 0; | |
803 do { | |
804 len = (unsigned)(next[copy++]); | |
805 if (state->head != Z_NULL && | |
806 state->head->comment != Z_NULL && | |
807 state->length < state->head->comm_max) | |
808 state->head->comment[state->length++] = (Bytef)len; | |
809 } while (len && copy < have); | |
810 if ((state->flags & 0x0200) && (state->wrap & 4)) | |
811 state->check = crc32(state->check, next, copy); | |
812 have -= copy; | |
813 next += copy; | |
814 if (len) goto inf_leave; | |
815 } | |
816 else if (state->head != Z_NULL) | |
817 state->head->comment = Z_NULL; | |
818 state->mode = HCRC; | |
819 case HCRC: | |
820 if (state->flags & 0x0200) { | |
821 NEEDBITS(16); | |
822 if ((state->wrap & 4) && hold != (state->check & 0xffff)) { | |
823 strm->msg = (char *)"header crc mismatch"; | |
824 state->mode = BAD; | |
825 break; | |
826 } | |
827 INITBITS(); | |
828 } | |
829 if (state->head != Z_NULL) { | |
830 state->head->hcrc = (int)((state->flags >> 9) & 1); | |
831 state->head->done = 1; | |
832 } | |
833 strm->adler = state->check = crc32(0L, Z_NULL, 0); | |
834 state->mode = TYPE; | |
835 break; | |
836 #endif | |
837 case DICTID: | |
838 NEEDBITS(32); | |
839 strm->adler = state->check = ZSWAP32(hold); | |
840 INITBITS(); | |
841 state->mode = DICT; | |
842 case DICT: | |
843 if (state->havedict == 0) { | |
844 RESTORE(); | |
845 return Z_NEED_DICT; | |
846 } | |
847 strm->adler = state->check = adler32(0L, Z_NULL, 0); | |
848 state->mode = TYPE; | |
849 case TYPE: | |
850 if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave; | |
851 case TYPEDO: | |
852 if (state->last) { | |
853 BYTEBITS(); | |
854 state->mode = CHECK; | |
855 break; | |
856 } | |
857 NEEDBITS(3); | |
858 state->last = BITS(1); | |
859 DROPBITS(1); | |
860 switch (BITS(2)) { | |
861 case 0: /* stored block */ | |
862 Tracev((stderr, "inflate: stored block%s\n", | |
863 state->last ? " (last)" : "")); | |
864 state->mode = STORED; | |
865 break; | |
866 case 1: /* fixed block */ | |
867 fixedtables(state); | |
868 Tracev((stderr, "inflate: fixed codes block%s\n", | |
869 state->last ? " (last)" : "")); | |
870 state->mode = LEN_; /* decode codes */ | |
871 if (flush == Z_TREES) { | |
872 DROPBITS(2); | |
873 goto inf_leave; | |
874 } | |
875 break; | |
876 case 2: /* dynamic block */ | |
877 Tracev((stderr, "inflate: dynamic codes block%s\n", | |
878 state->last ? " (last)" : "")); | |
879 state->mode = TABLE; | |
880 break; | |
881 case 3: | |
882 strm->msg = (char *)"invalid block type"; | |
883 state->mode = BAD; | |
884 } | |
885 DROPBITS(2); | |
886 break; | |
887 case STORED: | |
888 BYTEBITS(); /* go to byte boundary */ | |
889 NEEDBITS(32); | |
890 if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { | |
891 strm->msg = (char *)"invalid stored block lengths"; | |
892 state->mode = BAD; | |
893 break; | |
894 } | |
895 state->length = (unsigned)hold & 0xffff; | |
896 Tracev((stderr, "inflate: stored length %u\n", | |
897 state->length)); | |
898 INITBITS(); | |
899 state->mode = COPY_; | |
900 if (flush == Z_TREES) goto inf_leave; | |
901 case COPY_: | |
902 state->mode = COPY; | |
903 case COPY: | |
904 copy = state->length; | |
905 if (copy) { | |
906 if (copy > have) copy = have; | |
907 if (copy > left) copy = left; | |
908 if (copy == 0) goto inf_leave; | |
909 zmemcpy(put, next, copy); | |
910 have -= copy; | |
911 next += copy; | |
912 left -= copy; | |
913 put += copy; | |
914 state->length -= copy; | |
915 break; | |
916 } | |
917 Tracev((stderr, "inflate: stored end\n")); | |
918 state->mode = TYPE; | |
919 break; | |
920 case TABLE: | |
921 NEEDBITS(14); | |
922 state->nlen = BITS(5) + 257; | |
923 DROPBITS(5); | |
924 state->ndist = BITS(5) + 1; | |
925 DROPBITS(5); | |
926 state->ncode = BITS(4) + 4; | |
927 DROPBITS(4); | |
928 #ifndef PKZIP_BUG_WORKAROUND | |
929 if (state->nlen > 286 || state->ndist > 30) { | |
930 strm->msg = (char *)"too many length or distance symbols"; | |
931 state->mode = BAD; | |
932 break; | |
933 } | |
934 #endif | |
935 Tracev((stderr, "inflate: table sizes ok\n")); | |
936 state->have = 0; | |
937 state->mode = LENLENS; | |
938 case LENLENS: | |
939 while (state->have < state->ncode) { | |
940 NEEDBITS(3); | |
941 state->lens[order[state->have++]] = (unsigned short)BITS(3); | |
942 DROPBITS(3); | |
943 } | |
944 while (state->have < 19) | |
945 state->lens[order[state->have++]] = 0; | |
946 state->next = state->codes; | |
947 state->lencode = (const code FAR *)(state->next); | |
948 state->lenbits = 7; | |
949 ret = inflate_table(CODES, state->lens, 19, &(state->next), | |
950 &(state->lenbits), state->work); | |
951 if (ret) { | |
952 strm->msg = (char *)"invalid code lengths set"; | |
953 state->mode = BAD; | |
954 break; | |
955 } | |
956 Tracev((stderr, "inflate: code lengths ok\n")); | |
957 state->have = 0; | |
958 state->mode = CODELENS; | |
959 case CODELENS: | |
960 while (state->have < state->nlen + state->ndist) { | |
961 for (;;) { | |
962 here = state->lencode[BITS(state->lenbits)]; | |
963 if ((unsigned)(here.bits) <= bits) break; | |
964 PULLBYTE(); | |
965 } | |
966 if (here.val < 16) { | |
967 DROPBITS(here.bits); | |
968 state->lens[state->have++] = here.val; | |
969 } | |
970 else { | |
971 if (here.val == 16) { | |
972 NEEDBITS(here.bits + 2); | |
973 DROPBITS(here.bits); | |
974 if (state->have == 0) { | |
975 strm->msg = (char *)"invalid bit length repeat"; | |
976 state->mode = BAD; | |
977 break; | |
978 } | |
979 len = state->lens[state->have - 1]; | |
980 copy = 3 + BITS(2); | |
981 DROPBITS(2); | |
982 } | |
983 else if (here.val == 17) { | |
984 NEEDBITS(here.bits + 3); | |
985 DROPBITS(here.bits); | |
986 len = 0; | |
987 copy = 3 + BITS(3); | |
988 DROPBITS(3); | |
989 } | |
990 else { | |
991 NEEDBITS(here.bits + 7); | |
992 DROPBITS(here.bits); | |
993 len = 0; | |
994 copy = 11 + BITS(7); | |
995 DROPBITS(7); | |
996 } | |
997 if (state->have + copy > state->nlen + state->ndist) { | |
998 strm->msg = (char *)"invalid bit length repeat"; | |
999 state->mode = BAD; | |
1000 break; | |
1001 } | |
1002 while (copy--) | |
1003 state->lens[state->have++] = (unsigned short)len; | |
1004 } | |
1005 } | |
1006 | |
1007 /* handle error breaks in while */ | |
1008 if (state->mode == BAD) break; | |
1009 | |
1010 /* check for end-of-block code (better have one) */ | |
1011 if (state->lens[256] == 0) { | |
1012 strm->msg = (char *)"invalid code -- missing end-of-block"; | |
1013 state->mode = BAD; | |
1014 break; | |
1015 } | |
1016 | |
1017 /* build code tables -- note: do not change the lenbits or distbits | |
1018 values here (9 and 6) without reading the comments in inftrees.h | |
1019 concerning the ENOUGH constants, which depend on those values */ | |
1020 state->next = state->codes; | |
1021 state->lencode = (const code FAR *)(state->next); | |
1022 state->lenbits = 9; | |
1023 ret = inflate_table(LENS, state->lens, state->nlen, &(state->next), | |
1024 &(state->lenbits), state->work); | |
1025 if (ret) { | |
1026 strm->msg = (char *)"invalid literal/lengths set"; | |
1027 state->mode = BAD; | |
1028 break; | |
1029 } | |
1030 state->distcode = (const code FAR *)(state->next); | |
1031 state->distbits = 6; | |
1032 ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist, | |
1033 &(state->next), &(state->distbits), state->work); | |
1034 if (ret) { | |
1035 strm->msg = (char *)"invalid distances set"; | |
1036 state->mode = BAD; | |
1037 break; | |
1038 } | |
1039 Tracev((stderr, "inflate: codes ok\n")); | |
1040 state->mode = LEN_; | |
1041 if (flush == Z_TREES) goto inf_leave; | |
1042 case LEN_: | |
1043 state->mode = LEN; | |
1044 case LEN: | |
1045 if (have >= 6 && left >= 258) { | |
1046 RESTORE(); | |
1047 inflate_fast(strm, out); | |
1048 LOAD(); | |
1049 if (state->mode == TYPE) | |
1050 state->back = -1; | |
1051 break; | |
1052 } | |
1053 state->back = 0; | |
1054 for (;;) { | |
1055 here = state->lencode[BITS(state->lenbits)]; | |
1056 if ((unsigned)(here.bits) <= bits) break; | |
1057 PULLBYTE(); | |
1058 } | |
1059 if (here.op && (here.op & 0xf0) == 0) { | |
1060 last = here; | |
1061 for (;;) { | |
1062 here = state->lencode[last.val + | |
1063 (BITS(last.bits + last.op) >> last.bits)]; | |
1064 if ((unsigned)(last.bits + here.bits) <= bits) break; | |
1065 PULLBYTE(); | |
1066 } | |
1067 DROPBITS(last.bits); | |
1068 state->back += last.bits; | |
1069 } | |
1070 DROPBITS(here.bits); | |
1071 state->back += here.bits; | |
1072 state->length = (unsigned)here.val; | |
1073 if ((int)(here.op) == 0) { | |
1074 Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ? | |
1075 "inflate: literal '%c'\n" : | |
1076 "inflate: literal 0x%02x\n", here.val)); | |
1077 state->mode = LIT; | |
1078 break; | |
1079 } | |
1080 if (here.op & 32) { | |
1081 Tracevv((stderr, "inflate: end of block\n")); | |
1082 state->back = -1; | |
1083 state->mode = TYPE; | |
1084 break; | |
1085 } | |
1086 if (here.op & 64) { | |
1087 strm->msg = (char *)"invalid literal/length code"; | |
1088 state->mode = BAD; | |
1089 break; | |
1090 } | |
1091 state->extra = (unsigned)(here.op) & 15; | |
1092 state->mode = LENEXT; | |
1093 case LENEXT: | |
1094 if (state->extra) { | |
1095 NEEDBITS(state->extra); | |
1096 state->length += BITS(state->extra); | |
1097 DROPBITS(state->extra); | |
1098 state->back += state->extra; | |
1099 } | |
1100 Tracevv((stderr, "inflate: length %u\n", state->length)); | |
1101 state->was = state->length; | |
1102 state->mode = DIST; | |
1103 case DIST: | |
1104 for (;;) { | |
1105 here = state->distcode[BITS(state->distbits)]; | |
1106 if ((unsigned)(here.bits) <= bits) break; | |
1107 PULLBYTE(); | |
1108 } | |
1109 if ((here.op & 0xf0) == 0) { | |
1110 last = here; | |
1111 for (;;) { | |
1112 here = state->distcode[last.val + | |
1113 (BITS(last.bits + last.op) >> last.bits)]; | |
1114 if ((unsigned)(last.bits + here.bits) <= bits) break; | |
1115 PULLBYTE(); | |
1116 } | |
1117 DROPBITS(last.bits); | |
1118 state->back += last.bits; | |
1119 } | |
1120 DROPBITS(here.bits); | |
1121 state->back += here.bits; | |
1122 if (here.op & 64) { | |
1123 strm->msg = (char *)"invalid distance code"; | |
1124 state->mode = BAD; | |
1125 break; | |
1126 } | |
1127 state->offset = (unsigned)here.val; | |
1128 state->extra = (unsigned)(here.op) & 15; | |
1129 state->mode = DISTEXT; | |
1130 case DISTEXT: | |
1131 if (state->extra) { | |
1132 NEEDBITS(state->extra); | |
1133 state->offset += BITS(state->extra); | |
1134 DROPBITS(state->extra); | |
1135 state->back += state->extra; | |
1136 } | |
1137 #ifdef INFLATE_STRICT | |
1138 if (state->offset > state->dmax) { | |
1139 strm->msg = (char *)"invalid distance too far back"; | |
1140 state->mode = BAD; | |
1141 break; | |
1142 } | |
1143 #endif | |
1144 Tracevv((stderr, "inflate: distance %u\n", state->offset)); | |
1145 state->mode = MATCH; | |
1146 case MATCH: | |
1147 if (left == 0) goto inf_leave; | |
1148 copy = out - left; | |
1149 if (state->offset > copy) { /* copy from window */ | |
1150 copy = state->offset - copy; | |
1151 if (copy > state->whave) { | |
1152 if (state->sane) { | |
1153 strm->msg = (char *)"invalid distance too far back"; | |
1154 state->mode = BAD; | |
1155 break; | |
1156 } | |
1157 #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR | |
1158 Trace((stderr, "inflate.c too far\n")); | |
1159 copy -= state->whave; | |
1160 if (copy > state->length) copy = state->length; | |
1161 if (copy > left) copy = left; | |
1162 left -= copy; | |
1163 state->length -= copy; | |
1164 do { | |
1165 *put++ = 0; | |
1166 } while (--copy); | |
1167 if (state->length == 0) state->mode = LEN; | |
1168 break; | |
1169 #endif | |
1170 } | |
1171 if (copy > state->wnext) { | |
1172 copy -= state->wnext; | |
1173 from = state->window + (state->wsize - copy); | |
1174 } | |
1175 else | |
1176 from = state->window + (state->wnext - copy); | |
1177 if (copy > state->length) copy = state->length; | |
1178 } | |
1179 else { /* copy from output */ | |
1180 from = put - state->offset; | |
1181 copy = state->length; | |
1182 } | |
1183 if (copy > left) copy = left; | |
1184 left -= copy; | |
1185 state->length -= copy; | |
1186 do { | |
1187 *put++ = *from++; | |
1188 } while (--copy); | |
1189 if (state->length == 0) state->mode = LEN; | |
1190 break; | |
1191 case LIT: | |
1192 if (left == 0) goto inf_leave; | |
1193 *put++ = (unsigned char)(state->length); | |
1194 left--; | |
1195 state->mode = LEN; | |
1196 break; | |
1197 case CHECK: | |
1198 if (state->wrap) { | |
1199 NEEDBITS(32); | |
1200 out -= left; | |
1201 strm->total_out += out; | |
1202 state->total += out; | |
1203 if ((state->wrap & 4) && out) | |
1204 strm->adler = state->check = | |
1205 UPDATE(state->check, put - out, out); | |
1206 out = left; | |
1207 if ((state->wrap & 4) && ( | |
1208 #ifdef GUNZIP | |
1209 state->flags ? hold : | |
1210 #endif | |
1211 ZSWAP32(hold)) != state->check) { | |
1212 strm->msg = (char *)"incorrect data check"; | |
1213 state->mode = BAD; | |
1214 break; | |
1215 } | |
1216 INITBITS(); | |
1217 Tracev((stderr, "inflate: check matches trailer\n")); | |
1218 } | |
1219 #ifdef GUNZIP | |
1220 state->mode = LENGTH; | |
1221 case LENGTH: | |
1222 if (state->wrap && state->flags) { | |
1223 NEEDBITS(32); | |
1224 if (hold != (state->total & 0xffffffffUL)) { | |
1225 strm->msg = (char *)"incorrect length check"; | |
1226 state->mode = BAD; | |
1227 break; | |
1228 } | |
1229 INITBITS(); | |
1230 Tracev((stderr, "inflate: length matches trailer\n")); | |
1231 } | |
1232 #endif | |
1233 state->mode = DONE; | |
1234 case DONE: | |
1235 ret = Z_STREAM_END; | |
1236 goto inf_leave; | |
1237 case BAD: | |
1238 ret = Z_DATA_ERROR; | |
1239 goto inf_leave; | |
1240 case MEM: | |
1241 return Z_MEM_ERROR; | |
1242 case SYNC: | |
1243 default: | |
1244 return Z_STREAM_ERROR; | |
1245 } | |
1246 | |
1247 /* | |
1248 Return from inflate(), updating the total counts and the check value. | |
1249 If there was no progress during the inflate() call, return a buffer | |
1250 error. Call updatewindow() to create and/or update the window state. | |
1251 Note: a memory error from inflate() is non-recoverable. | |
1252 */ | |
1253 inf_leave: | |
1254 RESTORE(); | |
1255 if (state->wsize || (out != strm->avail_out && state->mode < BAD && | |
1256 (state->mode < CHECK || flush != Z_FINISH))) | |
1257 if (updatewindow(strm, strm->next_out, out - strm->avail_out)) { | |
1258 state->mode = MEM; | |
1259 return Z_MEM_ERROR; | |
1260 } | |
1261 in -= strm->avail_in; | |
1262 out -= strm->avail_out; | |
1263 strm->total_in += in; | |
1264 strm->total_out += out; | |
1265 state->total += out; | |
1266 if ((state->wrap & 4) && out) | |
1267 strm->adler = state->check = | |
1268 UPDATE(state->check, strm->next_out - out, out); | |
1269 strm->data_type = (int)state->bits + (state->last ? 64 : 0) + | |
1270 (state->mode == TYPE ? 128 : 0) + | |
1271 (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0); | |
1272 if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK) | |
1273 ret = Z_BUF_ERROR; | |
1274 return ret; | |
1275 } | |
1276 | |
1277 int ZEXPORT inflateEnd(strm) | |
1278 z_streamp strm; | |
1279 { | |
1280 struct inflate_state FAR *state; | |
1281 if (inflateStateCheck(strm)) | |
1282 return Z_STREAM_ERROR; | |
1283 state = (struct inflate_state FAR *)strm->state; | |
1284 if (state->window != Z_NULL) ZFREE(strm, state->window); | |
1285 ZFREE(strm, strm->state); | |
1286 strm->state = Z_NULL; | |
1287 Tracev((stderr, "inflate: end\n")); | |
1288 return Z_OK; | |
1289 } | |
1290 | |
1291 int ZEXPORT inflateGetDictionary(strm, dictionary, dictLength) | |
1292 z_streamp strm; | |
1293 Bytef *dictionary; | |
1294 uInt *dictLength; | |
1295 { | |
1296 struct inflate_state FAR *state; | |
1297 | |
1298 /* check state */ | |
1299 if (inflateStateCheck(strm)) return Z_STREAM_ERROR; | |
1300 state = (struct inflate_state FAR *)strm->state; | |
1301 | |
1302 /* copy dictionary */ | |
1303 if (state->whave && dictionary != Z_NULL) { | |
1304 zmemcpy(dictionary, state->window + state->wnext, | |
1305 state->whave - state->wnext); | |
1306 zmemcpy(dictionary + state->whave - state->wnext, | |
1307 state->window, state->wnext); | |
1308 } | |
1309 if (dictLength != Z_NULL) | |
1310 *dictLength = state->whave; | |
1311 return Z_OK; | |
1312 } | |
1313 | |
1314 int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength) | |
1315 z_streamp strm; | |
1316 const Bytef *dictionary; | |
1317 uInt dictLength; | |
1318 { | |
1319 struct inflate_state FAR *state; | |
1320 unsigned long dictid; | |
1321 int ret; | |
1322 | |
1323 /* check state */ | |
1324 if (inflateStateCheck(strm)) return Z_STREAM_ERROR; | |
1325 state = (struct inflate_state FAR *)strm->state; | |
1326 if (state->wrap != 0 && state->mode != DICT) | |
1327 return Z_STREAM_ERROR; | |
1328 | |
1329 /* check for correct dictionary identifier */ | |
1330 if (state->mode == DICT) { | |
1331 dictid = adler32(0L, Z_NULL, 0); | |
1332 dictid = adler32(dictid, dictionary, dictLength); | |
1333 if (dictid != state->check) | |
1334 return Z_DATA_ERROR; | |
1335 } | |
1336 | |
1337 /* copy dictionary to window using updatewindow(), which will amend the | |
1338 existing dictionary if appropriate */ | |
1339 ret = updatewindow(strm, dictionary + dictLength, dictLength); | |
1340 if (ret) { | |
1341 state->mode = MEM; | |
1342 return Z_MEM_ERROR; | |
1343 } | |
1344 state->havedict = 1; | |
1345 Tracev((stderr, "inflate: dictionary set\n")); | |
1346 return Z_OK; | |
1347 } | |
1348 | |
1349 int ZEXPORT inflateGetHeader(strm, head) | |
1350 z_streamp strm; | |
1351 gz_headerp head; | |
1352 { | |
1353 struct inflate_state FAR *state; | |
1354 | |
1355 /* check state */ | |
1356 if (inflateStateCheck(strm)) return Z_STREAM_ERROR; | |
1357 state = (struct inflate_state FAR *)strm->state; | |
1358 if ((state->wrap & 2) == 0) return Z_STREAM_ERROR; | |
1359 | |
1360 /* save header structure */ | |
1361 state->head = head; | |
1362 head->done = 0; | |
1363 return Z_OK; | |
1364 } | |
1365 | |
1366 /* | |
1367 Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found | |
1368 or when out of input. When called, *have is the number of pattern bytes | |
1369 found in order so far, in 0..3. On return *have is updated to the new | |
1370 state. If on return *have equals four, then the pattern was found and the | |
1371 return value is how many bytes were read including the last byte of the | |
1372 pattern. If *have is less than four, then the pattern has not been found | |
1373 yet and the return value is len. In the latter case, syncsearch() can be | |
1374 called again with more data and the *have state. *have is initialized to | |
1375 zero for the first call. | |
1376 */ | |
1377 local unsigned syncsearch(have, buf, len) | |
1378 unsigned FAR *have; | |
1379 const unsigned char FAR *buf; | |
1380 unsigned len; | |
1381 { | |
1382 unsigned got; | |
1383 unsigned next; | |
1384 | |
1385 got = *have; | |
1386 next = 0; | |
1387 while (next < len && got < 4) { | |
1388 if ((int)(buf[next]) == (got < 2 ? 0 : 0xff)) | |
1389 got++; | |
1390 else if (buf[next]) | |
1391 got = 0; | |
1392 else | |
1393 got = 4 - got; | |
1394 next++; | |
1395 } | |
1396 *have = got; | |
1397 return next; | |
1398 } | |
1399 | |
1400 int ZEXPORT inflateSync(strm) | |
1401 z_streamp strm; | |
1402 { | |
1403 unsigned len; /* number of bytes to look at or looked at */ | |
1404 unsigned long in, out; /* temporary to save total_in and total_out */ | |
1405 unsigned char buf[4]; /* to restore bit buffer to byte string */ | |
1406 struct inflate_state FAR *state; | |
1407 | |
1408 /* check parameters */ | |
1409 if (inflateStateCheck(strm)) return Z_STREAM_ERROR; | |
1410 state = (struct inflate_state FAR *)strm->state; | |
1411 if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR; | |
1412 | |
1413 /* if first time, start search in bit buffer */ | |
1414 if (state->mode != SYNC) { | |
1415 state->mode = SYNC; | |
1416 state->hold <<= state->bits & 7; | |
1417 state->bits -= state->bits & 7; | |
1418 len = 0; | |
1419 while (state->bits >= 8) { | |
1420 buf[len++] = (unsigned char)(state->hold); | |
1421 state->hold >>= 8; | |
1422 state->bits -= 8; | |
1423 } | |
1424 state->have = 0; | |
1425 syncsearch(&(state->have), buf, len); | |
1426 } | |
1427 | |
1428 /* search available input */ | |
1429 len = syncsearch(&(state->have), strm->next_in, strm->avail_in); | |
1430 strm->avail_in -= len; | |
1431 strm->next_in += len; | |
1432 strm->total_in += len; | |
1433 | |
1434 /* return no joy or set up to restart inflate() on a new block */ | |
1435 if (state->have != 4) return Z_DATA_ERROR; | |
1436 in = strm->total_in; out = strm->total_out; | |
1437 inflateReset(strm); | |
1438 strm->total_in = in; strm->total_out = out; | |
1439 state->mode = TYPE; | |
1440 return Z_OK; | |
1441 } | |
1442 | |
1443 /* | |
1444 Returns true if inflate is currently at the end of a block generated by | |
1445 Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP | |
1446 implementation to provide an additional safety check. PPP uses | |
1447 Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored | |
1448 block. When decompressing, PPP checks that at the end of input packet, | |
1449 inflate is waiting for these length bytes. | |
1450 */ | |
1451 int ZEXPORT inflateSyncPoint(strm) | |
1452 z_streamp strm; | |
1453 { | |
1454 struct inflate_state FAR *state; | |
1455 | |
1456 if (inflateStateCheck(strm)) return Z_STREAM_ERROR; | |
1457 state = (struct inflate_state FAR *)strm->state; | |
1458 return state->mode == STORED && state->bits == 0; | |
1459 } | |
1460 | |
1461 int ZEXPORT inflateCopy(dest, source) | |
1462 z_streamp dest; | |
1463 z_streamp source; | |
1464 { | |
1465 struct inflate_state FAR *state; | |
1466 struct inflate_state FAR *copy; | |
1467 unsigned char FAR *window; | |
1468 unsigned wsize; | |
1469 | |
1470 /* check input */ | |
1471 if (inflateStateCheck(source) || dest == Z_NULL) | |
1472 return Z_STREAM_ERROR; | |
1473 state = (struct inflate_state FAR *)source->state; | |
1474 | |
1475 /* allocate space */ | |
1476 copy = (struct inflate_state FAR *) | |
1477 ZALLOC(source, 1, sizeof(struct inflate_state)); | |
1478 if (copy == Z_NULL) return Z_MEM_ERROR; | |
1479 window = Z_NULL; | |
1480 if (state->window != Z_NULL) { | |
1481 window = (unsigned char FAR *) | |
1482 ZALLOC(source, 1U << state->wbits, sizeof(unsigned char)); | |
1483 if (window == Z_NULL) { | |
1484 ZFREE(source, copy); | |
1485 return Z_MEM_ERROR; | |
1486 } | |
1487 } | |
1488 | |
1489 /* copy state */ | |
1490 zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream)); | |
1491 zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state)); | |
1492 copy->strm = dest; | |
1493 if (state->lencode >= state->codes && | |
1494 state->lencode <= state->codes + ENOUGH - 1) { | |
1495 copy->lencode = copy->codes + (state->lencode - state->codes); | |
1496 copy->distcode = copy->codes + (state->distcode - state->codes); | |
1497 } | |
1498 copy->next = copy->codes + (state->next - state->codes); | |
1499 if (window != Z_NULL) { | |
1500 wsize = 1U << state->wbits; | |
1501 zmemcpy(window, state->window, wsize); | |
1502 } | |
1503 copy->window = window; | |
1504 dest->state = (struct internal_state FAR *)copy; | |
1505 return Z_OK; | |
1506 } | |
1507 | |
1508 int ZEXPORT inflateUndermine(strm, subvert) | |
1509 z_streamp strm; | |
1510 int subvert; | |
1511 { | |
1512 struct inflate_state FAR *state; | |
1513 | |
1514 if (inflateStateCheck(strm)) return Z_STREAM_ERROR; | |
1515 state = (struct inflate_state FAR *)strm->state; | |
1516 #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR | |
1517 state->sane = !subvert; | |
1518 return Z_OK; | |
1519 #else | |
1520 (void)subvert; | |
1521 state->sane = 1; | |
1522 return Z_DATA_ERROR; | |
1523 #endif | |
1524 } | |
1525 | |
1526 int ZEXPORT inflateValidate(strm, check) | |
1527 z_streamp strm; | |
1528 int check; | |
1529 { | |
1530 struct inflate_state FAR *state; | |
1531 | |
1532 if (inflateStateCheck(strm)) return Z_STREAM_ERROR; | |
1533 state = (struct inflate_state FAR *)strm->state; | |
1534 if (check) | |
1535 state->wrap |= 4; | |
1536 else | |
1537 state->wrap &= ~4; | |
1538 return Z_OK; | |
1539 } | |
1540 | |
1541 long ZEXPORT inflateMark(strm) | |
1542 z_streamp strm; | |
1543 { | |
1544 struct inflate_state FAR *state; | |
1545 | |
1546 if (inflateStateCheck(strm)) | |
1547 return -(1L << 16); | |
1548 state = (struct inflate_state FAR *)strm->state; | |
1549 return (long)(((unsigned long)((long)state->back)) << 16) + | |
1550 (state->mode == COPY ? state->length : | |
1551 (state->mode == MATCH ? state->was - state->length : 0)); | |
1552 } | |
1553 | |
1554 unsigned long ZEXPORT inflateCodesUsed(strm) | |
1555 z_streamp strm; | |
1556 { | |
1557 struct inflate_state FAR *state; | |
1558 if (inflateStateCheck(strm)) return (unsigned long)-1; | |
1559 state = (struct inflate_state FAR *)strm->state; | |
1560 return (unsigned long)(state->next - state->codes); | |
1561 } |