1 | /* inflate.c -- zlib decompression |
2 | * Copyright (C) 1995-2022 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 | local int inflateStateCheck(z_streamp strm) { |
95 | struct inflate_state FAR *state; |
96 | if (strm == Z_NULL || |
97 | strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) |
98 | return 1; |
99 | state = (struct inflate_state FAR *)strm->state; |
100 | if (state == Z_NULL || state->strm != strm || |
101 | state->mode < HEAD || state->mode > SYNC) |
102 | return 1; |
103 | return 0; |
104 | } |
105 | |
106 | int ZEXPORT inflateResetKeep(z_streamp strm) { |
107 | struct inflate_state FAR *state; |
108 | |
109 | if (inflateStateCheck(strm)) return Z_STREAM_ERROR; |
110 | state = (struct inflate_state FAR *)strm->state; |
111 | strm->total_in = strm->total_out = state->total = 0; |
112 | strm->msg = Z_NULL; |
113 | if (state->wrap) /* to support ill-conceived Java test suite */ |
114 | strm->adler = state->wrap & 1; |
115 | state->mode = HEAD; |
116 | state->last = 0; |
117 | state->havedict = 0; |
118 | state->flags = -1; |
119 | state->dmax = 32768U; |
120 | state->head = Z_NULL; |
121 | state->hold = 0; |
122 | state->bits = 0; |
123 | state->lencode = state->distcode = state->next = state->codes; |
124 | state->sane = 1; |
125 | state->back = -1; |
126 | Tracev((stderr, "inflate: reset\n" )); |
127 | return Z_OK; |
128 | } |
129 | |
130 | int ZEXPORT inflateReset(z_streamp strm) { |
131 | struct inflate_state FAR *state; |
132 | |
133 | if (inflateStateCheck(strm)) return Z_STREAM_ERROR; |
134 | state = (struct inflate_state FAR *)strm->state; |
135 | state->wsize = 0; |
136 | state->whave = 0; |
137 | state->wnext = 0; |
138 | return inflateResetKeep(strm); |
139 | } |
140 | |
141 | int ZEXPORT inflateReset2(z_streamp strm, int windowBits) { |
142 | int wrap; |
143 | struct inflate_state FAR *state; |
144 | |
145 | /* get the state */ |
146 | if (inflateStateCheck(strm)) return Z_STREAM_ERROR; |
147 | state = (struct inflate_state FAR *)strm->state; |
148 | |
149 | /* extract wrap request from windowBits parameter */ |
150 | if (windowBits < 0) { |
151 | if (windowBits < -15) |
152 | return Z_STREAM_ERROR; |
153 | wrap = 0; |
154 | windowBits = -windowBits; |
155 | } |
156 | else { |
157 | wrap = (windowBits >> 4) + 5; |
158 | #ifdef GUNZIP |
159 | if (windowBits < 48) |
160 | windowBits &= 15; |
161 | #endif |
162 | } |
163 | |
164 | /* set number of window bits, free window if different */ |
165 | if (windowBits && (windowBits < 8 || windowBits > 15)) |
166 | return Z_STREAM_ERROR; |
167 | if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) { |
168 | ZFREE(strm, state->window); |
169 | state->window = Z_NULL; |
170 | } |
171 | |
172 | /* update state and reset the rest of it */ |
173 | state->wrap = wrap; |
174 | state->wbits = (unsigned)windowBits; |
175 | return inflateReset(strm); |
176 | } |
177 | |
178 | int ZEXPORT inflateInit2_(z_streamp strm, int windowBits, |
179 | const char *version, int stream_size) { |
180 | int ret; |
181 | struct inflate_state FAR *state; |
182 | |
183 | if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || |
184 | stream_size != (int)(sizeof(z_stream))) |
185 | return Z_VERSION_ERROR; |
186 | if (strm == Z_NULL) return Z_STREAM_ERROR; |
187 | strm->msg = Z_NULL; /* in case we return an error */ |
188 | if (strm->zalloc == (alloc_func)0) { |
189 | #ifdef Z_SOLO |
190 | return Z_STREAM_ERROR; |
191 | #else |
192 | strm->zalloc = zcalloc; |
193 | strm->opaque = (voidpf)0; |
194 | #endif |
195 | } |
196 | if (strm->zfree == (free_func)0) |
197 | #ifdef Z_SOLO |
198 | return Z_STREAM_ERROR; |
199 | #else |
200 | strm->zfree = zcfree; |
201 | #endif |
202 | state = (struct inflate_state FAR *) |
203 | ZALLOC(strm, 1, sizeof(struct inflate_state)); |
204 | if (state == Z_NULL) return Z_MEM_ERROR; |
205 | Tracev((stderr, "inflate: allocated\n" )); |
206 | strm->state = (struct internal_state FAR *)state; |
207 | state->strm = strm; |
208 | state->window = Z_NULL; |
209 | state->mode = HEAD; /* to pass state test in inflateReset2() */ |
210 | ret = inflateReset2(strm, windowBits); |
211 | if (ret != Z_OK) { |
212 | ZFREE(strm, state); |
213 | strm->state = Z_NULL; |
214 | } |
215 | return ret; |
216 | } |
217 | |
218 | int ZEXPORT inflateInit_(z_streamp strm, const char *version, |
219 | int stream_size) { |
220 | return inflateInit2_(strm, DEF_WBITS, version, stream_size); |
221 | } |
222 | |
223 | int ZEXPORT inflatePrime(z_streamp strm, int bits, int value) { |
224 | struct inflate_state FAR *state; |
225 | |
226 | if (inflateStateCheck(strm)) return Z_STREAM_ERROR; |
227 | if (bits == 0) |
228 | return Z_OK; |
229 | state = (struct inflate_state FAR *)strm->state; |
230 | if (bits < 0) { |
231 | state->hold = 0; |
232 | state->bits = 0; |
233 | return Z_OK; |
234 | } |
235 | if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR; |
236 | value &= (1L << bits) - 1; |
237 | state->hold += (unsigned)value << state->bits; |
238 | state->bits += (uInt)bits; |
239 | return Z_OK; |
240 | } |
241 | |
242 | /* |
243 | Return state with length and distance decoding tables and index sizes set to |
244 | fixed code decoding. Normally this returns fixed tables from inffixed.h. |
245 | If BUILDFIXED is defined, then instead this routine builds the tables the |
246 | first time it's called, and returns those tables the first time and |
247 | thereafter. This reduces the size of the code by about 2K bytes, in |
248 | exchange for a little execution time. However, BUILDFIXED should not be |
249 | used for threaded applications, since the rewriting of the tables and virgin |
250 | may not be thread-safe. |
251 | */ |
252 | local void fixedtables(struct inflate_state FAR *state) { |
253 | #ifdef BUILDFIXED |
254 | static int virgin = 1; |
255 | static code *lenfix, *distfix; |
256 | static code fixed[544]; |
257 | |
258 | /* build fixed huffman tables if first call (may not be thread safe) */ |
259 | if (virgin) { |
260 | unsigned sym, bits; |
261 | static code *next; |
262 | |
263 | /* literal/length table */ |
264 | sym = 0; |
265 | while (sym < 144) state->lens[sym++] = 8; |
266 | while (sym < 256) state->lens[sym++] = 9; |
267 | while (sym < 280) state->lens[sym++] = 7; |
268 | while (sym < 288) state->lens[sym++] = 8; |
269 | next = fixed; |
270 | lenfix = next; |
271 | bits = 9; |
272 | inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work); |
273 | |
274 | /* distance table */ |
275 | sym = 0; |
276 | while (sym < 32) state->lens[sym++] = 5; |
277 | distfix = next; |
278 | bits = 5; |
279 | inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work); |
280 | |
281 | /* do this just once */ |
282 | virgin = 0; |
283 | } |
284 | #else /* !BUILDFIXED */ |
285 | # include "inffixed.h" |
286 | #endif /* BUILDFIXED */ |
287 | state->lencode = lenfix; |
288 | state->lenbits = 9; |
289 | state->distcode = distfix; |
290 | state->distbits = 5; |
291 | } |
292 | |
293 | #ifdef MAKEFIXED |
294 | #include <stdio.h> |
295 | |
296 | /* |
297 | Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also |
298 | defines BUILDFIXED, so the tables are built on the fly. makefixed() writes |
299 | those tables to stdout, which would be piped to inffixed.h. A small program |
300 | can simply call makefixed to do this: |
301 | |
302 | void makefixed(void); |
303 | |
304 | int main(void) |
305 | { |
306 | makefixed(); |
307 | return 0; |
308 | } |
309 | |
310 | Then that can be linked with zlib built with MAKEFIXED defined and run: |
311 | |
312 | a.out > inffixed.h |
313 | */ |
314 | void makefixed(void) |
315 | { |
316 | unsigned low, size; |
317 | struct inflate_state state; |
318 | |
319 | fixedtables(&state); |
320 | puts(" /* inffixed.h -- table for decoding fixed codes" ); |
321 | puts(" * Generated automatically by makefixed()." ); |
322 | puts(" */" ); |
323 | puts("" ); |
324 | puts(" /* WARNING: this file should *not* be used by applications." ); |
325 | puts(" It is part of the implementation of this library and is" ); |
326 | puts(" subject to change. Applications should only use zlib.h." ); |
327 | puts(" */" ); |
328 | puts("" ); |
329 | size = 1U << 9; |
330 | printf(" static const code lenfix[%u] = {" , size); |
331 | low = 0; |
332 | for (;;) { |
333 | if ((low % 7) == 0) printf("\n " ); |
334 | printf("{%u,%u,%d}" , (low & 127) == 99 ? 64 : state.lencode[low].op, |
335 | state.lencode[low].bits, state.lencode[low].val); |
336 | if (++low == size) break; |
337 | putchar(','); |
338 | } |
339 | puts("\n };" ); |
340 | size = 1U << 5; |
341 | printf("\n static const code distfix[%u] = {" , size); |
342 | low = 0; |
343 | for (;;) { |
344 | if ((low % 6) == 0) printf("\n " ); |
345 | printf("{%u,%u,%d}" , state.distcode[low].op, state.distcode[low].bits, |
346 | state.distcode[low].val); |
347 | if (++low == size) break; |
348 | putchar(','); |
349 | } |
350 | puts("\n };" ); |
351 | } |
352 | #endif /* MAKEFIXED */ |
353 | |
354 | /* |
355 | Update the window with the last wsize (normally 32K) bytes written before |
356 | returning. If window does not exist yet, create it. This is only called |
357 | when a window is already in use, or when output has been written during this |
358 | inflate call, but the end of the deflate stream has not been reached yet. |
359 | It is also called to create a window for dictionary data when a dictionary |
360 | is loaded. |
361 | |
362 | Providing output buffers larger than 32K to inflate() should provide a speed |
363 | advantage, since only the last 32K of output is copied to the sliding window |
364 | upon return from inflate(), and since all distances after the first 32K of |
365 | output will fall in the output data, making match copies simpler and faster. |
366 | The advantage may be dependent on the size of the processor's data caches. |
367 | */ |
368 | local int updatewindow(z_streamp strm, const Bytef *end, unsigned copy) { |
369 | struct inflate_state FAR *state; |
370 | unsigned dist; |
371 | |
372 | state = (struct inflate_state FAR *)strm->state; |
373 | |
374 | /* if it hasn't been done already, allocate space for the window */ |
375 | if (state->window == Z_NULL) { |
376 | state->window = (unsigned char FAR *) |
377 | ZALLOC(strm, 1U << state->wbits, |
378 | sizeof(unsigned char)); |
379 | if (state->window == Z_NULL) return 1; |
380 | } |
381 | |
382 | /* if window not in use yet, initialize */ |
383 | if (state->wsize == 0) { |
384 | state->wsize = 1U << state->wbits; |
385 | state->wnext = 0; |
386 | state->whave = 0; |
387 | } |
388 | |
389 | /* copy state->wsize or less output bytes into the circular window */ |
390 | if (copy >= state->wsize) { |
391 | zmemcpy(state->window, end - state->wsize, state->wsize); |
392 | state->wnext = 0; |
393 | state->whave = state->wsize; |
394 | } |
395 | else { |
396 | dist = state->wsize - state->wnext; |
397 | if (dist > copy) dist = copy; |
398 | zmemcpy(state->window + state->wnext, end - copy, dist); |
399 | copy -= dist; |
400 | if (copy) { |
401 | zmemcpy(state->window, end - copy, copy); |
402 | state->wnext = copy; |
403 | state->whave = state->wsize; |
404 | } |
405 | else { |
406 | state->wnext += dist; |
407 | if (state->wnext == state->wsize) state->wnext = 0; |
408 | if (state->whave < state->wsize) state->whave += dist; |
409 | } |
410 | } |
411 | return 0; |
412 | } |
413 | |
414 | /* Macros for inflate(): */ |
415 | |
416 | /* check function to use adler32() for zlib or crc32() for gzip */ |
417 | #ifdef GUNZIP |
418 | # define UPDATE_CHECK(check, buf, len) \ |
419 | (state->flags ? crc32(check, buf, len) : adler32(check, buf, len)) |
420 | #else |
421 | # define UPDATE_CHECK(check, buf, len) adler32(check, buf, len) |
422 | #endif |
423 | |
424 | /* check macros for header crc */ |
425 | #ifdef GUNZIP |
426 | # define CRC2(check, word) \ |
427 | do { \ |
428 | hbuf[0] = (unsigned char)(word); \ |
429 | hbuf[1] = (unsigned char)((word) >> 8); \ |
430 | check = crc32(check, hbuf, 2); \ |
431 | } while (0) |
432 | |
433 | # define CRC4(check, word) \ |
434 | do { \ |
435 | hbuf[0] = (unsigned char)(word); \ |
436 | hbuf[1] = (unsigned char)((word) >> 8); \ |
437 | hbuf[2] = (unsigned char)((word) >> 16); \ |
438 | hbuf[3] = (unsigned char)((word) >> 24); \ |
439 | check = crc32(check, hbuf, 4); \ |
440 | } while (0) |
441 | #endif |
442 | |
443 | /* Load registers with state in inflate() for speed */ |
444 | #define LOAD() \ |
445 | do { \ |
446 | put = strm->next_out; \ |
447 | left = strm->avail_out; \ |
448 | next = strm->next_in; \ |
449 | have = strm->avail_in; \ |
450 | hold = state->hold; \ |
451 | bits = state->bits; \ |
452 | } while (0) |
453 | |
454 | /* Restore state from registers in inflate() */ |
455 | #define RESTORE() \ |
456 | do { \ |
457 | strm->next_out = put; \ |
458 | strm->avail_out = left; \ |
459 | strm->next_in = next; \ |
460 | strm->avail_in = have; \ |
461 | state->hold = hold; \ |
462 | state->bits = bits; \ |
463 | } while (0) |
464 | |
465 | /* Clear the input bit accumulator */ |
466 | #define INITBITS() \ |
467 | do { \ |
468 | hold = 0; \ |
469 | bits = 0; \ |
470 | } while (0) |
471 | |
472 | /* Get a byte of input into the bit accumulator, or return from inflate() |
473 | if there is no input available. */ |
474 | #define PULLBYTE() \ |
475 | do { \ |
476 | if (have == 0) goto inf_leave; \ |
477 | have--; \ |
478 | hold += (unsigned long)(*next++) << bits; \ |
479 | bits += 8; \ |
480 | } while (0) |
481 | |
482 | /* Assure that there are at least n bits in the bit accumulator. If there is |
483 | not enough available input to do that, then return from inflate(). */ |
484 | #define NEEDBITS(n) \ |
485 | do { \ |
486 | while (bits < (unsigned)(n)) \ |
487 | PULLBYTE(); \ |
488 | } while (0) |
489 | |
490 | /* Return the low n bits of the bit accumulator (n < 16) */ |
491 | #define BITS(n) \ |
492 | ((unsigned)hold & ((1U << (n)) - 1)) |
493 | |
494 | /* Remove n bits from the bit accumulator */ |
495 | #define DROPBITS(n) \ |
496 | do { \ |
497 | hold >>= (n); \ |
498 | bits -= (unsigned)(n); \ |
499 | } while (0) |
500 | |
501 | /* Remove zero to seven bits as needed to go to a byte boundary */ |
502 | #define BYTEBITS() \ |
503 | do { \ |
504 | hold >>= bits & 7; \ |
505 | bits -= bits & 7; \ |
506 | } while (0) |
507 | |
508 | /* |
509 | inflate() uses a state machine to process as much input data and generate as |
510 | much output data as possible before returning. The state machine is |
511 | structured roughly as follows: |
512 | |
513 | for (;;) switch (state) { |
514 | ... |
515 | case STATEn: |
516 | if (not enough input data or output space to make progress) |
517 | return; |
518 | ... make progress ... |
519 | state = STATEm; |
520 | break; |
521 | ... |
522 | } |
523 | |
524 | so when inflate() is called again, the same case is attempted again, and |
525 | if the appropriate resources are provided, the machine proceeds to the |
526 | next state. The NEEDBITS() macro is usually the way the state evaluates |
527 | whether it can proceed or should return. NEEDBITS() does the return if |
528 | the requested bits are not available. The typical use of the BITS macros |
529 | is: |
530 | |
531 | NEEDBITS(n); |
532 | ... do something with BITS(n) ... |
533 | DROPBITS(n); |
534 | |
535 | where NEEDBITS(n) either returns from inflate() if there isn't enough |
536 | input left to load n bits into the accumulator, or it continues. BITS(n) |
537 | gives the low n bits in the accumulator. When done, DROPBITS(n) drops |
538 | the low n bits off the accumulator. INITBITS() clears the accumulator |
539 | and sets the number of available bits to zero. BYTEBITS() discards just |
540 | enough bits to put the accumulator on a byte boundary. After BYTEBITS() |
541 | and a NEEDBITS(8), then BITS(8) would return the next byte in the stream. |
542 | |
543 | NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return |
544 | if there is no input available. The decoding of variable length codes uses |
545 | PULLBYTE() directly in order to pull just enough bytes to decode the next |
546 | code, and no more. |
547 | |
548 | Some states loop until they get enough input, making sure that enough |
549 | state information is maintained to continue the loop where it left off |
550 | if NEEDBITS() returns in the loop. For example, want, need, and keep |
551 | would all have to actually be part of the saved state in case NEEDBITS() |
552 | returns: |
553 | |
554 | case STATEw: |
555 | while (want < need) { |
556 | NEEDBITS(n); |
557 | keep[want++] = BITS(n); |
558 | DROPBITS(n); |
559 | } |
560 | state = STATEx; |
561 | case STATEx: |
562 | |
563 | As shown above, if the next state is also the next case, then the break |
564 | is omitted. |
565 | |
566 | A state may also return if there is not enough output space available to |
567 | complete that state. Those states are copying stored data, writing a |
568 | literal byte, and copying a matching string. |
569 | |
570 | When returning, a "goto inf_leave" is used to update the total counters, |
571 | update the check value, and determine whether any progress has been made |
572 | during that inflate() call in order to return the proper return code. |
573 | Progress is defined as a change in either strm->avail_in or strm->avail_out. |
574 | When there is a window, goto inf_leave will update the window with the last |
575 | output written. If a goto inf_leave occurs in the middle of decompression |
576 | and there is no window currently, goto inf_leave will create one and copy |
577 | output to the window for the next call of inflate(). |
578 | |
579 | In this implementation, the flush parameter of inflate() only affects the |
580 | return code (per zlib.h). inflate() always writes as much as possible to |
581 | strm->next_out, given the space available and the provided input--the effect |
582 | documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers |
583 | the allocation of and copying into a sliding window until necessary, which |
584 | provides the effect documented in zlib.h for Z_FINISH when the entire input |
585 | stream available. So the only thing the flush parameter actually does is: |
586 | when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it |
587 | will return Z_BUF_ERROR if it has not reached the end of the stream. |
588 | */ |
589 | |
590 | int ZEXPORT inflate(z_streamp strm, int flush) { |
591 | struct inflate_state FAR *state; |
592 | z_const unsigned char FAR *next; /* next input */ |
593 | unsigned char FAR *put; /* next output */ |
594 | unsigned have, left; /* available input and output */ |
595 | unsigned long hold; /* bit buffer */ |
596 | unsigned bits; /* bits in bit buffer */ |
597 | unsigned in, out; /* save starting available input and output */ |
598 | unsigned copy; /* number of stored or match bytes to copy */ |
599 | unsigned char FAR *from; /* where to copy match bytes from */ |
600 | code here; /* current decoding table entry */ |
601 | code last; /* parent table entry */ |
602 | unsigned len; /* length to copy for repeats, bits to drop */ |
603 | int ret; /* return code */ |
604 | #ifdef GUNZIP |
605 | unsigned char hbuf[4]; /* buffer for gzip header crc calculation */ |
606 | #endif |
607 | static const unsigned short order[19] = /* permutation of code lengths */ |
608 | {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; |
609 | |
610 | if (inflateStateCheck(strm) || strm->next_out == Z_NULL || |
611 | (strm->next_in == Z_NULL && strm->avail_in != 0)) |
612 | return Z_STREAM_ERROR; |
613 | |
614 | state = (struct inflate_state FAR *)strm->state; |
615 | if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */ |
616 | LOAD(); |
617 | in = have; |
618 | out = left; |
619 | ret = Z_OK; |
620 | for (;;) |
621 | switch (state->mode) { |
622 | case HEAD: |
623 | if (state->wrap == 0) { |
624 | state->mode = TYPEDO; |
625 | break; |
626 | } |
627 | NEEDBITS(16); |
628 | #ifdef GUNZIP |
629 | if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */ |
630 | if (state->wbits == 0) |
631 | state->wbits = 15; |
632 | state->check = crc32(0L, Z_NULL, 0); |
633 | CRC2(state->check, hold); |
634 | INITBITS(); |
635 | state->mode = FLAGS; |
636 | break; |
637 | } |
638 | if (state->head != Z_NULL) |
639 | state->head->done = -1; |
640 | if (!(state->wrap & 1) || /* check if zlib header allowed */ |
641 | #else |
642 | if ( |
643 | #endif |
644 | ((BITS(8) << 8) + (hold >> 8)) % 31) { |
645 | strm->msg = (char *)"incorrect header check" ; |
646 | state->mode = BAD; |
647 | break; |
648 | } |
649 | if (BITS(4) != Z_DEFLATED) { |
650 | strm->msg = (char *)"unknown compression method" ; |
651 | state->mode = BAD; |
652 | break; |
653 | } |
654 | DROPBITS(4); |
655 | len = BITS(4) + 8; |
656 | if (state->wbits == 0) |
657 | state->wbits = len; |
658 | if (len > 15 || len > state->wbits) { |
659 | strm->msg = (char *)"invalid window size" ; |
660 | state->mode = BAD; |
661 | break; |
662 | } |
663 | state->dmax = 1U << len; |
664 | state->flags = 0; /* indicate zlib header */ |
665 | Tracev((stderr, "inflate: zlib header ok\n" )); |
666 | strm->adler = state->check = adler32(0L, Z_NULL, 0); |
667 | state->mode = hold & 0x200 ? DICTID : TYPE; |
668 | INITBITS(); |
669 | break; |
670 | #ifdef GUNZIP |
671 | case FLAGS: |
672 | NEEDBITS(16); |
673 | state->flags = (int)(hold); |
674 | if ((state->flags & 0xff) != Z_DEFLATED) { |
675 | strm->msg = (char *)"unknown compression method" ; |
676 | state->mode = BAD; |
677 | break; |
678 | } |
679 | if (state->flags & 0xe000) { |
680 | strm->msg = (char *)"unknown header flags set" ; |
681 | state->mode = BAD; |
682 | break; |
683 | } |
684 | if (state->head != Z_NULL) |
685 | state->head->text = (int)((hold >> 8) & 1); |
686 | if ((state->flags & 0x0200) && (state->wrap & 4)) |
687 | CRC2(state->check, hold); |
688 | INITBITS(); |
689 | state->mode = TIME; |
690 | /* fallthrough */ |
691 | case TIME: |
692 | NEEDBITS(32); |
693 | if (state->head != Z_NULL) |
694 | state->head->time = hold; |
695 | if ((state->flags & 0x0200) && (state->wrap & 4)) |
696 | CRC4(state->check, hold); |
697 | INITBITS(); |
698 | state->mode = OS; |
699 | /* fallthrough */ |
700 | case OS: |
701 | NEEDBITS(16); |
702 | if (state->head != Z_NULL) { |
703 | state->head->xflags = (int)(hold & 0xff); |
704 | state->head->os = (int)(hold >> 8); |
705 | } |
706 | if ((state->flags & 0x0200) && (state->wrap & 4)) |
707 | CRC2(state->check, hold); |
708 | INITBITS(); |
709 | state->mode = EXLEN; |
710 | /* fallthrough */ |
711 | case EXLEN: |
712 | if (state->flags & 0x0400) { |
713 | NEEDBITS(16); |
714 | state->length = (unsigned)(hold); |
715 | if (state->head != Z_NULL) |
716 | state->head->extra_len = (unsigned)hold; |
717 | if ((state->flags & 0x0200) && (state->wrap & 4)) |
718 | CRC2(state->check, hold); |
719 | INITBITS(); |
720 | } |
721 | else if (state->head != Z_NULL) |
722 | state->head->extra = Z_NULL; |
723 | state->mode = EXTRA; |
724 | /* fallthrough */ |
725 | case EXTRA: |
726 | if (state->flags & 0x0400) { |
727 | copy = state->length; |
728 | if (copy > have) copy = have; |
729 | if (copy) { |
730 | if (state->head != Z_NULL && |
731 | state->head->extra != Z_NULL && |
732 | (len = state->head->extra_len - state->length) < |
733 | state->head->extra_max) { |
734 | zmemcpy(state->head->extra + len, next, |
735 | len + copy > state->head->extra_max ? |
736 | state->head->extra_max - len : copy); |
737 | } |
738 | if ((state->flags & 0x0200) && (state->wrap & 4)) |
739 | state->check = crc32(state->check, next, copy); |
740 | have -= copy; |
741 | next += copy; |
742 | state->length -= copy; |
743 | } |
744 | if (state->length) goto inf_leave; |
745 | } |
746 | state->length = 0; |
747 | state->mode = NAME; |
748 | /* fallthrough */ |
749 | case NAME: |
750 | if (state->flags & 0x0800) { |
751 | if (have == 0) goto inf_leave; |
752 | copy = 0; |
753 | do { |
754 | len = (unsigned)(next[copy++]); |
755 | if (state->head != Z_NULL && |
756 | state->head->name != Z_NULL && |
757 | state->length < state->head->name_max) |
758 | state->head->name[state->length++] = (Bytef)len; |
759 | } while (len && copy < have); |
760 | if ((state->flags & 0x0200) && (state->wrap & 4)) |
761 | state->check = crc32(state->check, next, copy); |
762 | have -= copy; |
763 | next += copy; |
764 | if (len) goto inf_leave; |
765 | } |
766 | else if (state->head != Z_NULL) |
767 | state->head->name = Z_NULL; |
768 | state->length = 0; |
769 | state->mode = COMMENT; |
770 | /* fallthrough */ |
771 | case COMMENT: |
772 | if (state->flags & 0x1000) { |
773 | if (have == 0) goto inf_leave; |
774 | copy = 0; |
775 | do { |
776 | len = (unsigned)(next[copy++]); |
777 | if (state->head != Z_NULL && |
778 | state->head->comment != Z_NULL && |
779 | state->length < state->head->comm_max) |
780 | state->head->comment[state->length++] = (Bytef)len; |
781 | } while (len && copy < have); |
782 | if ((state->flags & 0x0200) && (state->wrap & 4)) |
783 | state->check = crc32(state->check, next, copy); |
784 | have -= copy; |
785 | next += copy; |
786 | if (len) goto inf_leave; |
787 | } |
788 | else if (state->head != Z_NULL) |
789 | state->head->comment = Z_NULL; |
790 | state->mode = HCRC; |
791 | /* fallthrough */ |
792 | case HCRC: |
793 | if (state->flags & 0x0200) { |
794 | NEEDBITS(16); |
795 | if ((state->wrap & 4) && hold != (state->check & 0xffff)) { |
796 | strm->msg = (char *)"header crc mismatch" ; |
797 | state->mode = BAD; |
798 | break; |
799 | } |
800 | INITBITS(); |
801 | } |
802 | if (state->head != Z_NULL) { |
803 | state->head->hcrc = (int)((state->flags >> 9) & 1); |
804 | state->head->done = 1; |
805 | } |
806 | strm->adler = state->check = crc32(0L, Z_NULL, 0); |
807 | state->mode = TYPE; |
808 | break; |
809 | #endif |
810 | case DICTID: |
811 | NEEDBITS(32); |
812 | strm->adler = state->check = ZSWAP32(hold); |
813 | INITBITS(); |
814 | state->mode = DICT; |
815 | /* fallthrough */ |
816 | case DICT: |
817 | if (state->havedict == 0) { |
818 | RESTORE(); |
819 | return Z_NEED_DICT; |
820 | } |
821 | strm->adler = state->check = adler32(0L, Z_NULL, 0); |
822 | state->mode = TYPE; |
823 | /* fallthrough */ |
824 | case TYPE: |
825 | if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave; |
826 | /* fallthrough */ |
827 | case TYPEDO: |
828 | if (state->last) { |
829 | BYTEBITS(); |
830 | state->mode = CHECK; |
831 | break; |
832 | } |
833 | NEEDBITS(3); |
834 | state->last = BITS(1); |
835 | DROPBITS(1); |
836 | switch (BITS(2)) { |
837 | case 0: /* stored block */ |
838 | Tracev((stderr, "inflate: stored block%s\n" , |
839 | state->last ? " (last)" : "" )); |
840 | state->mode = STORED; |
841 | break; |
842 | case 1: /* fixed block */ |
843 | fixedtables(state); |
844 | Tracev((stderr, "inflate: fixed codes block%s\n" , |
845 | state->last ? " (last)" : "" )); |
846 | state->mode = LEN_; /* decode codes */ |
847 | if (flush == Z_TREES) { |
848 | DROPBITS(2); |
849 | goto inf_leave; |
850 | } |
851 | break; |
852 | case 2: /* dynamic block */ |
853 | Tracev((stderr, "inflate: dynamic codes block%s\n" , |
854 | state->last ? " (last)" : "" )); |
855 | state->mode = TABLE; |
856 | break; |
857 | case 3: |
858 | strm->msg = (char *)"invalid block type" ; |
859 | state->mode = BAD; |
860 | } |
861 | DROPBITS(2); |
862 | break; |
863 | case STORED: |
864 | BYTEBITS(); /* go to byte boundary */ |
865 | NEEDBITS(32); |
866 | if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { |
867 | strm->msg = (char *)"invalid stored block lengths" ; |
868 | state->mode = BAD; |
869 | break; |
870 | } |
871 | state->length = (unsigned)hold & 0xffff; |
872 | Tracev((stderr, "inflate: stored length %u\n" , |
873 | state->length)); |
874 | INITBITS(); |
875 | state->mode = COPY_; |
876 | if (flush == Z_TREES) goto inf_leave; |
877 | /* fallthrough */ |
878 | case COPY_: |
879 | state->mode = COPY; |
880 | /* fallthrough */ |
881 | case COPY: |
882 | copy = state->length; |
883 | if (copy) { |
884 | if (copy > have) copy = have; |
885 | if (copy > left) copy = left; |
886 | if (copy == 0) goto inf_leave; |
887 | zmemcpy(put, next, copy); |
888 | have -= copy; |
889 | next += copy; |
890 | left -= copy; |
891 | put += copy; |
892 | state->length -= copy; |
893 | break; |
894 | } |
895 | Tracev((stderr, "inflate: stored end\n" )); |
896 | state->mode = TYPE; |
897 | break; |
898 | case TABLE: |
899 | NEEDBITS(14); |
900 | state->nlen = BITS(5) + 257; |
901 | DROPBITS(5); |
902 | state->ndist = BITS(5) + 1; |
903 | DROPBITS(5); |
904 | state->ncode = BITS(4) + 4; |
905 | DROPBITS(4); |
906 | #ifndef PKZIP_BUG_WORKAROUND |
907 | if (state->nlen > 286 || state->ndist > 30) { |
908 | strm->msg = (char *)"too many length or distance symbols" ; |
909 | state->mode = BAD; |
910 | break; |
911 | } |
912 | #endif |
913 | Tracev((stderr, "inflate: table sizes ok\n" )); |
914 | state->have = 0; |
915 | state->mode = LENLENS; |
916 | /* fallthrough */ |
917 | case LENLENS: |
918 | while (state->have < state->ncode) { |
919 | NEEDBITS(3); |
920 | state->lens[order[state->have++]] = (unsigned short)BITS(3); |
921 | DROPBITS(3); |
922 | } |
923 | while (state->have < 19) |
924 | state->lens[order[state->have++]] = 0; |
925 | state->next = state->codes; |
926 | state->lencode = (const code FAR *)(state->next); |
927 | state->lenbits = 7; |
928 | ret = inflate_table(CODES, state->lens, 19, &(state->next), |
929 | &(state->lenbits), state->work); |
930 | if (ret) { |
931 | strm->msg = (char *)"invalid code lengths set" ; |
932 | state->mode = BAD; |
933 | break; |
934 | } |
935 | Tracev((stderr, "inflate: code lengths ok\n" )); |
936 | state->have = 0; |
937 | state->mode = CODELENS; |
938 | /* fallthrough */ |
939 | case CODELENS: |
940 | while (state->have < state->nlen + state->ndist) { |
941 | for (;;) { |
942 | here = state->lencode[BITS(state->lenbits)]; |
943 | if ((unsigned)(here.bits) <= bits) break; |
944 | PULLBYTE(); |
945 | } |
946 | if (here.val < 16) { |
947 | DROPBITS(here.bits); |
948 | state->lens[state->have++] = here.val; |
949 | } |
950 | else { |
951 | if (here.val == 16) { |
952 | NEEDBITS(here.bits + 2); |
953 | DROPBITS(here.bits); |
954 | if (state->have == 0) { |
955 | strm->msg = (char *)"invalid bit length repeat" ; |
956 | state->mode = BAD; |
957 | break; |
958 | } |
959 | len = state->lens[state->have - 1]; |
960 | copy = 3 + BITS(2); |
961 | DROPBITS(2); |
962 | } |
963 | else if (here.val == 17) { |
964 | NEEDBITS(here.bits + 3); |
965 | DROPBITS(here.bits); |
966 | len = 0; |
967 | copy = 3 + BITS(3); |
968 | DROPBITS(3); |
969 | } |
970 | else { |
971 | NEEDBITS(here.bits + 7); |
972 | DROPBITS(here.bits); |
973 | len = 0; |
974 | copy = 11 + BITS(7); |
975 | DROPBITS(7); |
976 | } |
977 | if (state->have + copy > state->nlen + state->ndist) { |
978 | strm->msg = (char *)"invalid bit length repeat" ; |
979 | state->mode = BAD; |
980 | break; |
981 | } |
982 | while (copy--) |
983 | state->lens[state->have++] = (unsigned short)len; |
984 | } |
985 | } |
986 | |
987 | /* handle error breaks in while */ |
988 | if (state->mode == BAD) break; |
989 | |
990 | /* check for end-of-block code (better have one) */ |
991 | if (state->lens[256] == 0) { |
992 | strm->msg = (char *)"invalid code -- missing end-of-block" ; |
993 | state->mode = BAD; |
994 | break; |
995 | } |
996 | |
997 | /* build code tables -- note: do not change the lenbits or distbits |
998 | values here (9 and 6) without reading the comments in inftrees.h |
999 | concerning the ENOUGH constants, which depend on those values */ |
1000 | state->next = state->codes; |
1001 | state->lencode = (const code FAR *)(state->next); |
1002 | state->lenbits = 9; |
1003 | ret = inflate_table(LENS, state->lens, state->nlen, &(state->next), |
1004 | &(state->lenbits), state->work); |
1005 | if (ret) { |
1006 | strm->msg = (char *)"invalid literal/lengths set" ; |
1007 | state->mode = BAD; |
1008 | break; |
1009 | } |
1010 | state->distcode = (const code FAR *)(state->next); |
1011 | state->distbits = 6; |
1012 | ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist, |
1013 | &(state->next), &(state->distbits), state->work); |
1014 | if (ret) { |
1015 | strm->msg = (char *)"invalid distances set" ; |
1016 | state->mode = BAD; |
1017 | break; |
1018 | } |
1019 | Tracev((stderr, "inflate: codes ok\n" )); |
1020 | state->mode = LEN_; |
1021 | if (flush == Z_TREES) goto inf_leave; |
1022 | /* fallthrough */ |
1023 | case LEN_: |
1024 | state->mode = LEN; |
1025 | /* fallthrough */ |
1026 | case LEN: |
1027 | if (have >= 6 && left >= 258) { |
1028 | RESTORE(); |
1029 | inflate_fast(strm, out); |
1030 | LOAD(); |
1031 | if (state->mode == TYPE) |
1032 | state->back = -1; |
1033 | break; |
1034 | } |
1035 | state->back = 0; |
1036 | for (;;) { |
1037 | here = state->lencode[BITS(state->lenbits)]; |
1038 | if ((unsigned)(here.bits) <= bits) break; |
1039 | PULLBYTE(); |
1040 | } |
1041 | if (here.op && (here.op & 0xf0) == 0) { |
1042 | last = here; |
1043 | for (;;) { |
1044 | here = state->lencode[last.val + |
1045 | (BITS(last.bits + last.op) >> last.bits)]; |
1046 | if ((unsigned)(last.bits + here.bits) <= bits) break; |
1047 | PULLBYTE(); |
1048 | } |
1049 | DROPBITS(last.bits); |
1050 | state->back += last.bits; |
1051 | } |
1052 | DROPBITS(here.bits); |
1053 | state->back += here.bits; |
1054 | state->length = (unsigned)here.val; |
1055 | if ((int)(here.op) == 0) { |
1056 | Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ? |
1057 | "inflate: literal '%c'\n" : |
1058 | "inflate: literal 0x%02x\n" , here.val)); |
1059 | state->mode = LIT; |
1060 | break; |
1061 | } |
1062 | if (here.op & 32) { |
1063 | Tracevv((stderr, "inflate: end of block\n" )); |
1064 | state->back = -1; |
1065 | state->mode = TYPE; |
1066 | break; |
1067 | } |
1068 | if (here.op & 64) { |
1069 | strm->msg = (char *)"invalid literal/length code" ; |
1070 | state->mode = BAD; |
1071 | break; |
1072 | } |
1073 | state->extra = (unsigned)(here.op) & 15; |
1074 | state->mode = LENEXT; |
1075 | /* fallthrough */ |
1076 | case LENEXT: |
1077 | if (state->extra) { |
1078 | NEEDBITS(state->extra); |
1079 | state->length += BITS(state->extra); |
1080 | DROPBITS(state->extra); |
1081 | state->back += state->extra; |
1082 | } |
1083 | Tracevv((stderr, "inflate: length %u\n" , state->length)); |
1084 | state->was = state->length; |
1085 | state->mode = DIST; |
1086 | /* fallthrough */ |
1087 | case DIST: |
1088 | for (;;) { |
1089 | here = state->distcode[BITS(state->distbits)]; |
1090 | if ((unsigned)(here.bits) <= bits) break; |
1091 | PULLBYTE(); |
1092 | } |
1093 | if ((here.op & 0xf0) == 0) { |
1094 | last = here; |
1095 | for (;;) { |
1096 | here = state->distcode[last.val + |
1097 | (BITS(last.bits + last.op) >> last.bits)]; |
1098 | if ((unsigned)(last.bits + here.bits) <= bits) break; |
1099 | PULLBYTE(); |
1100 | } |
1101 | DROPBITS(last.bits); |
1102 | state->back += last.bits; |
1103 | } |
1104 | DROPBITS(here.bits); |
1105 | state->back += here.bits; |
1106 | if (here.op & 64) { |
1107 | strm->msg = (char *)"invalid distance code" ; |
1108 | state->mode = BAD; |
1109 | break; |
1110 | } |
1111 | state->offset = (unsigned)here.val; |
1112 | state->extra = (unsigned)(here.op) & 15; |
1113 | state->mode = DISTEXT; |
1114 | /* fallthrough */ |
1115 | case DISTEXT: |
1116 | if (state->extra) { |
1117 | NEEDBITS(state->extra); |
1118 | state->offset += BITS(state->extra); |
1119 | DROPBITS(state->extra); |
1120 | state->back += state->extra; |
1121 | } |
1122 | #ifdef INFLATE_STRICT |
1123 | if (state->offset > state->dmax) { |
1124 | strm->msg = (char *)"invalid distance too far back" ; |
1125 | state->mode = BAD; |
1126 | break; |
1127 | } |
1128 | #endif |
1129 | Tracevv((stderr, "inflate: distance %u\n" , state->offset)); |
1130 | state->mode = MATCH; |
1131 | /* fallthrough */ |
1132 | case MATCH: |
1133 | if (left == 0) goto inf_leave; |
1134 | copy = out - left; |
1135 | if (state->offset > copy) { /* copy from window */ |
1136 | copy = state->offset - copy; |
1137 | if (copy > state->whave) { |
1138 | if (state->sane) { |
1139 | strm->msg = (char *)"invalid distance too far back" ; |
1140 | state->mode = BAD; |
1141 | break; |
1142 | } |
1143 | #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR |
1144 | Trace((stderr, "inflate.c too far\n" )); |
1145 | copy -= state->whave; |
1146 | if (copy > state->length) copy = state->length; |
1147 | if (copy > left) copy = left; |
1148 | left -= copy; |
1149 | state->length -= copy; |
1150 | do { |
1151 | *put++ = 0; |
1152 | } while (--copy); |
1153 | if (state->length == 0) state->mode = LEN; |
1154 | break; |
1155 | #endif |
1156 | } |
1157 | if (copy > state->wnext) { |
1158 | copy -= state->wnext; |
1159 | from = state->window + (state->wsize - copy); |
1160 | } |
1161 | else |
1162 | from = state->window + (state->wnext - copy); |
1163 | if (copy > state->length) copy = state->length; |
1164 | } |
1165 | else { /* copy from output */ |
1166 | from = put - state->offset; |
1167 | copy = state->length; |
1168 | } |
1169 | if (copy > left) copy = left; |
1170 | left -= copy; |
1171 | state->length -= copy; |
1172 | do { |
1173 | *put++ = *from++; |
1174 | } while (--copy); |
1175 | if (state->length == 0) state->mode = LEN; |
1176 | break; |
1177 | case LIT: |
1178 | if (left == 0) goto inf_leave; |
1179 | *put++ = (unsigned char)(state->length); |
1180 | left--; |
1181 | state->mode = LEN; |
1182 | break; |
1183 | case CHECK: |
1184 | if (state->wrap) { |
1185 | NEEDBITS(32); |
1186 | out -= left; |
1187 | strm->total_out += out; |
1188 | state->total += out; |
1189 | if ((state->wrap & 4) && out) |
1190 | strm->adler = state->check = |
1191 | UPDATE_CHECK(state->check, put - out, out); |
1192 | out = left; |
1193 | if ((state->wrap & 4) && ( |
1194 | #ifdef GUNZIP |
1195 | state->flags ? hold : |
1196 | #endif |
1197 | ZSWAP32(hold)) != state->check) { |
1198 | strm->msg = (char *)"incorrect data check" ; |
1199 | state->mode = BAD; |
1200 | break; |
1201 | } |
1202 | INITBITS(); |
1203 | Tracev((stderr, "inflate: check matches trailer\n" )); |
1204 | } |
1205 | #ifdef GUNZIP |
1206 | state->mode = LENGTH; |
1207 | /* fallthrough */ |
1208 | case LENGTH: |
1209 | if (state->wrap && state->flags) { |
1210 | NEEDBITS(32); |
1211 | if ((state->wrap & 4) && hold != (state->total & 0xffffffff)) { |
1212 | strm->msg = (char *)"incorrect length check" ; |
1213 | state->mode = BAD; |
1214 | break; |
1215 | } |
1216 | INITBITS(); |
1217 | Tracev((stderr, "inflate: length matches trailer\n" )); |
1218 | } |
1219 | #endif |
1220 | state->mode = DONE; |
1221 | /* fallthrough */ |
1222 | case DONE: |
1223 | ret = Z_STREAM_END; |
1224 | goto inf_leave; |
1225 | case BAD: |
1226 | ret = Z_DATA_ERROR; |
1227 | goto inf_leave; |
1228 | case MEM: |
1229 | return Z_MEM_ERROR; |
1230 | case SYNC: |
1231 | /* fallthrough */ |
1232 | default: |
1233 | return Z_STREAM_ERROR; |
1234 | } |
1235 | |
1236 | /* |
1237 | Return from inflate(), updating the total counts and the check value. |
1238 | If there was no progress during the inflate() call, return a buffer |
1239 | error. Call updatewindow() to create and/or update the window state. |
1240 | Note: a memory error from inflate() is non-recoverable. |
1241 | */ |
1242 | inf_leave: |
1243 | RESTORE(); |
1244 | if (state->wsize || (out != strm->avail_out && state->mode < BAD && |
1245 | (state->mode < CHECK || flush != Z_FINISH))) |
1246 | if (updatewindow(strm, strm->next_out, out - strm->avail_out)) { |
1247 | state->mode = MEM; |
1248 | return Z_MEM_ERROR; |
1249 | } |
1250 | in -= strm->avail_in; |
1251 | out -= strm->avail_out; |
1252 | strm->total_in += in; |
1253 | strm->total_out += out; |
1254 | state->total += out; |
1255 | if ((state->wrap & 4) && out) |
1256 | strm->adler = state->check = |
1257 | UPDATE_CHECK(state->check, strm->next_out - out, out); |
1258 | strm->data_type = (int)state->bits + (state->last ? 64 : 0) + |
1259 | (state->mode == TYPE ? 128 : 0) + |
1260 | (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0); |
1261 | if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK) |
1262 | ret = Z_BUF_ERROR; |
1263 | return ret; |
1264 | } |
1265 | |
1266 | int ZEXPORT inflateEnd(z_streamp strm) { |
1267 | struct inflate_state FAR *state; |
1268 | if (inflateStateCheck(strm)) |
1269 | return Z_STREAM_ERROR; |
1270 | state = (struct inflate_state FAR *)strm->state; |
1271 | if (state->window != Z_NULL) ZFREE(strm, state->window); |
1272 | ZFREE(strm, strm->state); |
1273 | strm->state = Z_NULL; |
1274 | Tracev((stderr, "inflate: end\n" )); |
1275 | return Z_OK; |
1276 | } |
1277 | |
1278 | int ZEXPORT inflateGetDictionary(z_streamp strm, Bytef *dictionary, |
1279 | uInt *dictLength) { |
1280 | struct inflate_state FAR *state; |
1281 | |
1282 | /* check state */ |
1283 | if (inflateStateCheck(strm)) return Z_STREAM_ERROR; |
1284 | state = (struct inflate_state FAR *)strm->state; |
1285 | |
1286 | /* copy dictionary */ |
1287 | if (state->whave && dictionary != Z_NULL) { |
1288 | zmemcpy(dictionary, state->window + state->wnext, |
1289 | state->whave - state->wnext); |
1290 | zmemcpy(dictionary + state->whave - state->wnext, |
1291 | state->window, state->wnext); |
1292 | } |
1293 | if (dictLength != Z_NULL) |
1294 | *dictLength = state->whave; |
1295 | return Z_OK; |
1296 | } |
1297 | |
1298 | int ZEXPORT inflateSetDictionary(z_streamp strm, const Bytef *dictionary, |
1299 | uInt dictLength) { |
1300 | struct inflate_state FAR *state; |
1301 | unsigned long dictid; |
1302 | int ret; |
1303 | |
1304 | /* check state */ |
1305 | if (inflateStateCheck(strm)) return Z_STREAM_ERROR; |
1306 | state = (struct inflate_state FAR *)strm->state; |
1307 | if (state->wrap != 0 && state->mode != DICT) |
1308 | return Z_STREAM_ERROR; |
1309 | |
1310 | /* check for correct dictionary identifier */ |
1311 | if (state->mode == DICT) { |
1312 | dictid = adler32(0L, Z_NULL, 0); |
1313 | dictid = adler32(dictid, dictionary, dictLength); |
1314 | if (dictid != state->check) |
1315 | return Z_DATA_ERROR; |
1316 | } |
1317 | |
1318 | /* copy dictionary to window using updatewindow(), which will amend the |
1319 | existing dictionary if appropriate */ |
1320 | ret = updatewindow(strm, dictionary + dictLength, dictLength); |
1321 | if (ret) { |
1322 | state->mode = MEM; |
1323 | return Z_MEM_ERROR; |
1324 | } |
1325 | state->havedict = 1; |
1326 | Tracev((stderr, "inflate: dictionary set\n" )); |
1327 | return Z_OK; |
1328 | } |
1329 | |
1330 | int ZEXPORT (z_streamp strm, gz_headerp head) { |
1331 | struct inflate_state FAR *state; |
1332 | |
1333 | /* check state */ |
1334 | if (inflateStateCheck(strm)) return Z_STREAM_ERROR; |
1335 | state = (struct inflate_state FAR *)strm->state; |
1336 | if ((state->wrap & 2) == 0) return Z_STREAM_ERROR; |
1337 | |
1338 | /* save header structure */ |
1339 | state->head = head; |
1340 | head->done = 0; |
1341 | return Z_OK; |
1342 | } |
1343 | |
1344 | /* |
1345 | Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found |
1346 | or when out of input. When called, *have is the number of pattern bytes |
1347 | found in order so far, in 0..3. On return *have is updated to the new |
1348 | state. If on return *have equals four, then the pattern was found and the |
1349 | return value is how many bytes were read including the last byte of the |
1350 | pattern. If *have is less than four, then the pattern has not been found |
1351 | yet and the return value is len. In the latter case, syncsearch() can be |
1352 | called again with more data and the *have state. *have is initialized to |
1353 | zero for the first call. |
1354 | */ |
1355 | local unsigned syncsearch(unsigned FAR *have, const unsigned char FAR *buf, |
1356 | unsigned len) { |
1357 | unsigned got; |
1358 | unsigned next; |
1359 | |
1360 | got = *have; |
1361 | next = 0; |
1362 | while (next < len && got < 4) { |
1363 | if ((int)(buf[next]) == (got < 2 ? 0 : 0xff)) |
1364 | got++; |
1365 | else if (buf[next]) |
1366 | got = 0; |
1367 | else |
1368 | got = 4 - got; |
1369 | next++; |
1370 | } |
1371 | *have = got; |
1372 | return next; |
1373 | } |
1374 | |
1375 | int ZEXPORT inflateSync(z_streamp strm) { |
1376 | unsigned len; /* number of bytes to look at or looked at */ |
1377 | int flags; /* temporary to save header status */ |
1378 | unsigned long in, out; /* temporary to save total_in and total_out */ |
1379 | unsigned char buf[4]; /* to restore bit buffer to byte string */ |
1380 | struct inflate_state FAR *state; |
1381 | |
1382 | /* check parameters */ |
1383 | if (inflateStateCheck(strm)) return Z_STREAM_ERROR; |
1384 | state = (struct inflate_state FAR *)strm->state; |
1385 | if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR; |
1386 | |
1387 | /* if first time, start search in bit buffer */ |
1388 | if (state->mode != SYNC) { |
1389 | state->mode = SYNC; |
1390 | state->hold <<= state->bits & 7; |
1391 | state->bits -= state->bits & 7; |
1392 | len = 0; |
1393 | while (state->bits >= 8) { |
1394 | buf[len++] = (unsigned char)(state->hold); |
1395 | state->hold >>= 8; |
1396 | state->bits -= 8; |
1397 | } |
1398 | state->have = 0; |
1399 | syncsearch(&(state->have), buf, len); |
1400 | } |
1401 | |
1402 | /* search available input */ |
1403 | len = syncsearch(&(state->have), strm->next_in, strm->avail_in); |
1404 | strm->avail_in -= len; |
1405 | strm->next_in += len; |
1406 | strm->total_in += len; |
1407 | |
1408 | /* return no joy or set up to restart inflate() on a new block */ |
1409 | if (state->have != 4) return Z_DATA_ERROR; |
1410 | if (state->flags == -1) |
1411 | state->wrap = 0; /* if no header yet, treat as raw */ |
1412 | else |
1413 | state->wrap &= ~4; /* no point in computing a check value now */ |
1414 | flags = state->flags; |
1415 | in = strm->total_in; out = strm->total_out; |
1416 | inflateReset(strm); |
1417 | strm->total_in = in; strm->total_out = out; |
1418 | state->flags = flags; |
1419 | state->mode = TYPE; |
1420 | return Z_OK; |
1421 | } |
1422 | |
1423 | /* |
1424 | Returns true if inflate is currently at the end of a block generated by |
1425 | Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP |
1426 | implementation to provide an additional safety check. PPP uses |
1427 | Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored |
1428 | block. When decompressing, PPP checks that at the end of input packet, |
1429 | inflate is waiting for these length bytes. |
1430 | */ |
1431 | int ZEXPORT inflateSyncPoint(z_streamp strm) { |
1432 | struct inflate_state FAR *state; |
1433 | |
1434 | if (inflateStateCheck(strm)) return Z_STREAM_ERROR; |
1435 | state = (struct inflate_state FAR *)strm->state; |
1436 | return state->mode == STORED && state->bits == 0; |
1437 | } |
1438 | |
1439 | int ZEXPORT inflateCopy(z_streamp dest, z_streamp source) { |
1440 | struct inflate_state FAR *state; |
1441 | struct inflate_state FAR *copy; |
1442 | unsigned char FAR *window; |
1443 | unsigned wsize; |
1444 | |
1445 | /* check input */ |
1446 | if (inflateStateCheck(source) || dest == Z_NULL) |
1447 | return Z_STREAM_ERROR; |
1448 | state = (struct inflate_state FAR *)source->state; |
1449 | |
1450 | /* allocate space */ |
1451 | copy = (struct inflate_state FAR *) |
1452 | ZALLOC(source, 1, sizeof(struct inflate_state)); |
1453 | if (copy == Z_NULL) return Z_MEM_ERROR; |
1454 | window = Z_NULL; |
1455 | if (state->window != Z_NULL) { |
1456 | window = (unsigned char FAR *) |
1457 | ZALLOC(source, 1U << state->wbits, sizeof(unsigned char)); |
1458 | if (window == Z_NULL) { |
1459 | ZFREE(source, copy); |
1460 | return Z_MEM_ERROR; |
1461 | } |
1462 | } |
1463 | |
1464 | /* copy state */ |
1465 | zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream)); |
1466 | zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state)); |
1467 | copy->strm = dest; |
1468 | if (state->lencode >= state->codes && |
1469 | state->lencode <= state->codes + ENOUGH - 1) { |
1470 | copy->lencode = copy->codes + (state->lencode - state->codes); |
1471 | copy->distcode = copy->codes + (state->distcode - state->codes); |
1472 | } |
1473 | copy->next = copy->codes + (state->next - state->codes); |
1474 | if (window != Z_NULL) { |
1475 | wsize = 1U << state->wbits; |
1476 | zmemcpy(window, state->window, wsize); |
1477 | } |
1478 | copy->window = window; |
1479 | dest->state = (struct internal_state FAR *)copy; |
1480 | return Z_OK; |
1481 | } |
1482 | |
1483 | int ZEXPORT inflateUndermine(z_streamp strm, int subvert) { |
1484 | struct inflate_state FAR *state; |
1485 | |
1486 | if (inflateStateCheck(strm)) return Z_STREAM_ERROR; |
1487 | state = (struct inflate_state FAR *)strm->state; |
1488 | #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR |
1489 | state->sane = !subvert; |
1490 | return Z_OK; |
1491 | #else |
1492 | (void)subvert; |
1493 | state->sane = 1; |
1494 | return Z_DATA_ERROR; |
1495 | #endif |
1496 | } |
1497 | |
1498 | int ZEXPORT inflateValidate(z_streamp strm, int check) { |
1499 | struct inflate_state FAR *state; |
1500 | |
1501 | if (inflateStateCheck(strm)) return Z_STREAM_ERROR; |
1502 | state = (struct inflate_state FAR *)strm->state; |
1503 | if (check && state->wrap) |
1504 | state->wrap |= 4; |
1505 | else |
1506 | state->wrap &= ~4; |
1507 | return Z_OK; |
1508 | } |
1509 | |
1510 | long ZEXPORT inflateMark(z_streamp strm) { |
1511 | struct inflate_state FAR *state; |
1512 | |
1513 | if (inflateStateCheck(strm)) |
1514 | return -(1L << 16); |
1515 | state = (struct inflate_state FAR *)strm->state; |
1516 | return (long)(((unsigned long)((long)state->back)) << 16) + |
1517 | (state->mode == COPY ? state->length : |
1518 | (state->mode == MATCH ? state->was - state->length : 0)); |
1519 | } |
1520 | |
1521 | unsigned long ZEXPORT inflateCodesUsed(z_streamp strm) { |
1522 | struct inflate_state FAR *state; |
1523 | if (inflateStateCheck(strm)) return (unsigned long)-1; |
1524 | state = (struct inflate_state FAR *)strm->state; |
1525 | return (unsigned long)(state->next - state->codes); |
1526 | } |
1527 | |