1 | /* |
2 | * Copyright (c) 2008 Apple Inc. All rights reserved. |
3 | * |
4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
5 | * |
6 | * This file contains Original Code and/or Modifications of Original Code |
7 | * as defined in and that are subject to the Apple Public Source License |
8 | * Version 2.0 (the 'License'). You may not use this file except in |
9 | * compliance with the License. The rights granted to you under the License |
10 | * may not be used to create, or enable the creation or redistribution of, |
11 | * unlawful or unlicensed copies of an Apple operating system, or to |
12 | * circumvent, violate, or enable the circumvention or violation of, any |
13 | * terms of an Apple operating system software license agreement. |
14 | * |
15 | * Please obtain a copy of the License at |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
17 | * |
18 | * The Original Code and all software distributed under the License are |
19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
23 | * Please see the License for the specific language governing rights and |
24 | * limitations under the License. |
25 | * |
26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
27 | */ |
28 | /* inflate.c -- zlib decompression |
29 | * Copyright (C) 1995-2005 Mark Adler |
30 | * For conditions of distribution and use, see copyright notice in zlib.h |
31 | */ |
32 | |
33 | /* |
34 | * Change history: |
35 | * |
36 | * 1.2.beta0 24 Nov 2002 |
37 | * - First version -- complete rewrite of inflate to simplify code, avoid |
38 | * creation of window when not needed, minimize use of window when it is |
39 | * needed, make inffast.c even faster, implement gzip decoding, and to |
40 | * improve code readability and style over the previous zlib inflate code |
41 | * |
42 | * 1.2.beta1 25 Nov 2002 |
43 | * - Use pointers for available input and output checking in inffast.c |
44 | * - Remove input and output counters in inffast.c |
45 | * - Change inffast.c entry and loop from avail_in >= 7 to >= 6 |
46 | * - Remove unnecessary second byte pull from length extra in inffast.c |
47 | * - Unroll direct copy to three copies per loop in inffast.c |
48 | * |
49 | * 1.2.beta2 4 Dec 2002 |
50 | * - Change external routine names to reduce potential conflicts |
51 | * - Correct filename to inffixed.h for fixed tables in inflate.c |
52 | * - Make hbuf[] unsigned char to match parameter type in inflate.c |
53 | * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset) |
54 | * to avoid negation problem on Alphas (64 bit) in inflate.c |
55 | * |
56 | * 1.2.beta3 22 Dec 2002 |
57 | * - Add comments on state->bits assertion in inffast.c |
58 | * - Add comments on op field in inftrees.h |
59 | * - Fix bug in reuse of allocated window after inflateReset() |
60 | * - Remove bit fields--back to byte structure for speed |
61 | * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths |
62 | * - Change post-increments to pre-increments in inflate_fast(), PPC biased? |
63 | * - Add compile time option, POSTINC, to use post-increments instead (Intel?) |
64 | * - Make MATCH copy in inflate() much faster for when inflate_fast() not used |
65 | * - Use local copies of stream next and avail values, as well as local bit |
66 | * buffer and bit count in inflate()--for speed when inflate_fast() not used |
67 | * |
68 | * 1.2.beta4 1 Jan 2003 |
69 | * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings |
70 | * - Move a comment on output buffer sizes from inffast.c to inflate.c |
71 | * - Add comments in inffast.c to introduce the inflate_fast() routine |
72 | * - Rearrange window copies in inflate_fast() for speed and simplification |
73 | * - Unroll last copy for window match in inflate_fast() |
74 | * - Use local copies of window variables in inflate_fast() for speed |
75 | * - Pull out common write == 0 case for speed in inflate_fast() |
76 | * - Make op and len in inflate_fast() unsigned for consistency |
77 | * - Add FAR to lcode and dcode declarations in inflate_fast() |
78 | * - Simplified bad distance check in inflate_fast() |
79 | * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new |
80 | * source file infback.c to provide a call-back interface to inflate for |
81 | * programs like gzip and unzip -- uses window as output buffer to avoid |
82 | * window copying |
83 | * |
84 | * 1.2.beta5 1 Jan 2003 |
85 | * - Improved inflateBack() interface to allow the caller to provide initial |
86 | * input in strm. |
87 | * - Fixed stored blocks bug in inflateBack() |
88 | * |
89 | * 1.2.beta6 4 Jan 2003 |
90 | * - Added comments in inffast.c on effectiveness of POSTINC |
91 | * - Typecasting all around to reduce compiler warnings |
92 | * - Changed loops from while (1) or do {} while (1) to for (;;), again to |
93 | * make compilers happy |
94 | * - Changed type of window in inflateBackInit() to unsigned char * |
95 | * |
96 | * 1.2.beta7 27 Jan 2003 |
97 | * - Changed many types to unsigned or unsigned short to avoid warnings |
98 | * - Added inflateCopy() function |
99 | * |
100 | * 1.2.0 9 Mar 2003 |
101 | * - Changed inflateBack() interface to provide separate opaque descriptors |
102 | * for the in() and out() functions |
103 | * - Changed inflateBack() argument and in_func typedef to swap the length |
104 | * and buffer address return values for the input function |
105 | * - Check next_in and next_out for Z_NULL on entry to inflate() |
106 | * |
107 | * The history for versions after 1.2.0 are in ChangeLog in zlib distribution. |
108 | */ |
109 | |
110 | #include "zutil.h" |
111 | #include "inftrees.h" |
112 | #include "inflate.h" |
113 | #include "inffast.h" |
114 | |
115 | #ifdef MAKEFIXED |
116 | # ifndef BUILDFIXED |
117 | # define BUILDFIXED |
118 | # endif |
119 | #endif |
120 | |
121 | /* function prototypes */ |
122 | local void fixedtables OF((struct inflate_state FAR *state)); |
123 | local int updatewindow OF((z_streamp strm, unsigned out)); |
124 | #ifdef BUILDFIXED |
125 | void makefixed OF((void)); |
126 | #endif |
127 | local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf, |
128 | unsigned len)); |
129 | |
130 | int ZEXPORT |
131 | inflateReset(z_streamp strm) |
132 | { |
133 | struct inflate_state FAR *state; |
134 | |
135 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
136 | state = (struct inflate_state FAR *)strm->state; |
137 | strm->total_in = strm->total_out = state->total = 0; |
138 | strm->msg = Z_NULL; |
139 | strm->adler = 1; /* to support ill-conceived Java test suite */ |
140 | state->mode = HEAD; |
141 | state->last = 0; |
142 | state->havedict = 0; |
143 | state->dmax = 32768U; |
144 | state->head = Z_NULL; |
145 | state->wsize = 0; |
146 | state->whave = 0; |
147 | state->write = 0; |
148 | state->hold = 0; |
149 | state->bits = 0; |
150 | state->lencode = state->distcode = state->next = state->codes; |
151 | Tracev((stderr, "inflate: reset\n" )); |
152 | return Z_OK; |
153 | } |
154 | |
155 | int ZEXPORT |
156 | inflatePrime(z_streamp strm, int bits, int value) |
157 | { |
158 | struct inflate_state FAR *state; |
159 | |
160 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
161 | state = (struct inflate_state FAR *)strm->state; |
162 | if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR; |
163 | value &= (1L << bits) - 1; |
164 | state->hold += value << state->bits; |
165 | state->bits += bits; |
166 | return Z_OK; |
167 | } |
168 | |
169 | int ZEXPORT |
170 | inflateInit2_(z_streamp strm, int windowBits, const char *version, |
171 | int stream_size) |
172 | { |
173 | struct inflate_state FAR *state; |
174 | |
175 | if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || |
176 | stream_size != (int)(sizeof(z_stream))) |
177 | return Z_VERSION_ERROR; |
178 | if (strm == Z_NULL) return Z_STREAM_ERROR; |
179 | strm->msg = Z_NULL; /* in case we return an error */ |
180 | #ifndef NO_ZCFUNCS |
181 | if (strm->zalloc == (alloc_func)0) { |
182 | strm->zalloc = zcalloc; |
183 | strm->opaque = (voidpf)0; |
184 | } |
185 | if (strm->zfree == (free_func)0) strm->zfree = zcfree; |
186 | #endif /* NO_ZCFUNCS */ |
187 | state = (struct inflate_state FAR *) |
188 | ZALLOC(strm, 1, sizeof(struct inflate_state)); |
189 | if (state == Z_NULL) return Z_MEM_ERROR; |
190 | Tracev((stderr, "inflate: allocated\n" )); |
191 | strm->state = (struct internal_state FAR *)state; |
192 | if (windowBits < 0) { |
193 | state->wrap = 0; |
194 | windowBits = -windowBits; |
195 | } |
196 | else { |
197 | state->wrap = (windowBits >> 4) + 1; |
198 | #ifdef GUNZIP |
199 | if (windowBits < 48) windowBits &= 15; |
200 | #endif |
201 | } |
202 | if (windowBits < 8 || windowBits > 15) { |
203 | ZFREE(strm, state); |
204 | strm->state = Z_NULL; |
205 | return Z_STREAM_ERROR; |
206 | } |
207 | state->wbits = (unsigned)windowBits; |
208 | state->window = Z_NULL; |
209 | return inflateReset(strm); |
210 | } |
211 | |
212 | int ZEXPORT |
213 | inflateInit_(z_streamp strm, const char *version, int stream_size) |
214 | { |
215 | return inflateInit2_(strm, DEF_WBITS, version, stream_size); |
216 | } |
217 | |
218 | /* |
219 | Return state with length and distance decoding tables and index sizes set to |
220 | fixed code decoding. Normally this returns fixed tables from inffixed.h. |
221 | If BUILDFIXED is defined, then instead this routine builds the tables the |
222 | first time it's called, and returns those tables the first time and |
223 | thereafter. This reduces the size of the code by about 2K bytes, in |
224 | exchange for a little execution time. However, BUILDFIXED should not be |
225 | used for threaded applications, since the rewriting of the tables and virgin |
226 | may not be thread-safe. |
227 | */ |
228 | local void |
229 | fixedtables(struct inflate_state FAR *state) |
230 | { |
231 | #ifdef BUILDFIXED |
232 | static int virgin = 1; |
233 | static code *lenfix, *distfix; |
234 | static code fixed[544]; |
235 | |
236 | /* build fixed huffman tables if first call (may not be thread safe) */ |
237 | if (virgin) { |
238 | unsigned sym, bits; |
239 | static code *next; |
240 | |
241 | /* literal/length table */ |
242 | sym = 0; |
243 | while (sym < 144) state->lens[sym++] = 8; |
244 | while (sym < 256) state->lens[sym++] = 9; |
245 | while (sym < 280) state->lens[sym++] = 7; |
246 | while (sym < 288) state->lens[sym++] = 8; |
247 | next = fixed; |
248 | lenfix = next; |
249 | bits = 9; |
250 | inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work); |
251 | |
252 | /* distance table */ |
253 | sym = 0; |
254 | while (sym < 32) state->lens[sym++] = 5; |
255 | distfix = next; |
256 | bits = 5; |
257 | inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work); |
258 | |
259 | /* do this just once */ |
260 | virgin = 0; |
261 | } |
262 | #else /* !BUILDFIXED */ |
263 | # include "inffixed.h" |
264 | #endif /* BUILDFIXED */ |
265 | state->lencode = lenfix; |
266 | state->lenbits = 9; |
267 | state->distcode = distfix; |
268 | state->distbits = 5; |
269 | } |
270 | |
271 | #ifdef MAKEFIXED |
272 | #include <stdio.h> |
273 | |
274 | /* |
275 | Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also |
276 | defines BUILDFIXED, so the tables are built on the fly. makefixed() writes |
277 | those tables to stdout, which would be piped to inffixed.h. A small program |
278 | can simply call makefixed to do this: |
279 | |
280 | void makefixed(void); |
281 | |
282 | int main(void) |
283 | { |
284 | makefixed(); |
285 | return 0; |
286 | } |
287 | |
288 | Then that can be linked with zlib built with MAKEFIXED defined and run: |
289 | |
290 | a.out > inffixed.h |
291 | */ |
292 | void |
293 | makefixed(void) |
294 | { |
295 | unsigned low, size; |
296 | struct inflate_state state; |
297 | |
298 | fixedtables(&state); |
299 | puts(" /* inffixed.h -- table for decoding fixed codes" ); |
300 | puts(" * Generated automatically by makefixed()." ); |
301 | puts(" */" ); |
302 | puts("" ); |
303 | puts(" /* WARNING: this file should *not* be used by applications." ); |
304 | puts(" It is part of the implementation of this library and is" ); |
305 | puts(" subject to change. Applications should only use zlib.h." ); |
306 | puts(" */" ); |
307 | puts("" ); |
308 | size = 1U << 9; |
309 | printf(" static const code lenfix[%u] = {" , size); |
310 | low = 0; |
311 | for (;;) { |
312 | if ((low % 7) == 0) printf("\n " ); |
313 | printf("{%u,%u,%d}" , state.lencode[low].op, state.lencode[low].bits, |
314 | state.lencode[low].val); |
315 | if (++low == size) break; |
316 | putchar(','); |
317 | } |
318 | puts("\n };" ); |
319 | size = 1U << 5; |
320 | printf("\n static const code distfix[%u] = {" , size); |
321 | low = 0; |
322 | for (;;) { |
323 | if ((low % 6) == 0) printf("\n " ); |
324 | printf("{%u,%u,%d}" , state.distcode[low].op, state.distcode[low].bits, |
325 | state.distcode[low].val); |
326 | if (++low == size) break; |
327 | putchar(','); |
328 | } |
329 | puts("\n };" ); |
330 | } |
331 | #endif /* MAKEFIXED */ |
332 | |
333 | /* |
334 | Update the window with the last wsize (normally 32K) bytes written before |
335 | returning. If window does not exist yet, create it. This is only called |
336 | when a window is already in use, or when output has been written during this |
337 | inflate call, but the end of the deflate stream has not been reached yet. |
338 | It is also called to create a window for dictionary data when a dictionary |
339 | is loaded. |
340 | |
341 | Providing output buffers larger than 32K to inflate() should provide a speed |
342 | advantage, since only the last 32K of output is copied to the sliding window |
343 | upon return from inflate(), and since all distances after the first 32K of |
344 | output will fall in the output data, making match copies simpler and faster. |
345 | The advantage may be dependent on the size of the processor's data caches. |
346 | */ |
347 | local int |
348 | updatewindow(z_streamp strm, unsigned out) |
349 | { |
350 | struct inflate_state FAR *state; |
351 | unsigned copy, dist; |
352 | |
353 | state = (struct inflate_state FAR *)strm->state; |
354 | |
355 | /* if it hasn't been done already, allocate space for the window */ |
356 | if (state->window == Z_NULL) { |
357 | state->window = (unsigned char FAR *) |
358 | ZALLOC(strm, 1U << state->wbits, |
359 | sizeof(unsigned char)); |
360 | if (state->window == Z_NULL) return 1; |
361 | } |
362 | |
363 | /* if window not in use yet, initialize */ |
364 | if (state->wsize == 0) { |
365 | state->wsize = 1U << state->wbits; |
366 | state->write = 0; |
367 | state->whave = 0; |
368 | } |
369 | |
370 | /* copy state->wsize or less output bytes into the circular window */ |
371 | copy = out - strm->avail_out; |
372 | if (copy >= state->wsize) { |
373 | zmemcpy(state->window, strm->next_out - state->wsize, state->wsize); |
374 | state->write = 0; |
375 | state->whave = state->wsize; |
376 | } |
377 | else { |
378 | dist = state->wsize - state->write; |
379 | if (dist > copy) dist = copy; |
380 | zmemcpy(state->window + state->write, strm->next_out - copy, dist); |
381 | copy -= dist; |
382 | if (copy) { |
383 | zmemcpy(state->window, strm->next_out - copy, copy); |
384 | state->write = copy; |
385 | state->whave = state->wsize; |
386 | } |
387 | else { |
388 | state->write += dist; |
389 | if (state->write == state->wsize) state->write = 0; |
390 | if (state->whave < state->wsize) state->whave += dist; |
391 | } |
392 | } |
393 | return 0; |
394 | } |
395 | |
396 | /* Macros for inflate(): */ |
397 | |
398 | /* check function to use adler32() for zlib or z_crc32() for gzip */ |
399 | #ifdef GUNZIP |
400 | # define UPDATE(check, buf, len) \ |
401 | (state->flags ? z_crc32(check, buf, len) : adler32(check, buf, len)) |
402 | #else |
403 | # define UPDATE(check, buf, len) adler32(check, buf, len) |
404 | #endif |
405 | |
406 | /* check macros for header crc */ |
407 | #ifdef GUNZIP |
408 | # define CRC2(check, word) \ |
409 | do { \ |
410 | hbuf[0] = (unsigned char)(word); \ |
411 | hbuf[1] = (unsigned char)((word) >> 8); \ |
412 | check = z_crc32(check, hbuf, 2); \ |
413 | } while (0) |
414 | |
415 | # define CRC4(check, word) \ |
416 | do { \ |
417 | hbuf[0] = (unsigned char)(word); \ |
418 | hbuf[1] = (unsigned char)((word) >> 8); \ |
419 | hbuf[2] = (unsigned char)((word) >> 16); \ |
420 | hbuf[3] = (unsigned char)((word) >> 24); \ |
421 | check = z_crc32(check, hbuf, 4); \ |
422 | } while (0) |
423 | #endif |
424 | |
425 | /* Load registers with state in inflate() for speed */ |
426 | #define LOAD() \ |
427 | do { \ |
428 | put = strm->next_out; \ |
429 | left = strm->avail_out; \ |
430 | next = strm->next_in; \ |
431 | have = strm->avail_in; \ |
432 | hold = state->hold; \ |
433 | bits = state->bits; \ |
434 | } while (0) |
435 | |
436 | /* Restore state from registers in inflate() */ |
437 | #define RESTORE() \ |
438 | do { \ |
439 | strm->next_out = put; \ |
440 | strm->avail_out = left; \ |
441 | strm->next_in = next; \ |
442 | strm->avail_in = have; \ |
443 | state->hold = hold; \ |
444 | state->bits = bits; \ |
445 | } while (0) |
446 | |
447 | /* Clear the input bit accumulator */ |
448 | #define INITBITS() \ |
449 | do { \ |
450 | hold = 0; \ |
451 | bits = 0; \ |
452 | } while (0) |
453 | |
454 | /* Get a byte of input into the bit accumulator, or return from inflate() |
455 | if there is no input available. */ |
456 | #define PULLBYTE() \ |
457 | do { \ |
458 | if (have == 0) goto inf_leave; \ |
459 | have--; \ |
460 | hold += (unsigned long)(*next++) << bits; \ |
461 | bits += 8; \ |
462 | } while (0) |
463 | |
464 | /* Assure that there are at least n bits in the bit accumulator. If there is |
465 | not enough available input to do that, then return from inflate(). */ |
466 | #define NEEDBITS(n) \ |
467 | do { \ |
468 | while (bits < (unsigned)(n)) \ |
469 | PULLBYTE(); \ |
470 | } while (0) |
471 | |
472 | /* Return the low n bits of the bit accumulator (n < 16) */ |
473 | #define BITS(n) \ |
474 | ((unsigned)hold & ((1U << (n)) - 1)) |
475 | |
476 | /* Remove n bits from the bit accumulator */ |
477 | #define DROPBITS(n) \ |
478 | do { \ |
479 | hold >>= (n); \ |
480 | bits -= (unsigned)(n); \ |
481 | } while (0) |
482 | |
483 | /* Remove zero to seven bits as needed to go to a byte boundary */ |
484 | #define BYTEBITS() \ |
485 | do { \ |
486 | hold >>= bits & 7; \ |
487 | bits -= bits & 7; \ |
488 | } while (0) |
489 | |
490 | /* Reverse the bytes in a 32-bit value */ |
491 | #define REVERSE(q) \ |
492 | ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \ |
493 | (((q) & 0xff00) << 8) + (((q) & 0xff) << 24)) |
494 | |
495 | /* |
496 | inflate() uses a state machine to process as much input data and generate as |
497 | much output data as possible before returning. The state machine is |
498 | structured roughly as follows: |
499 | |
500 | for (;;) switch (state) { |
501 | ... |
502 | case STATEn: |
503 | if (not enough input data or output space to make progress) |
504 | return; |
505 | ... make progress ... |
506 | state = STATEm; |
507 | break; |
508 | ... |
509 | } |
510 | |
511 | so when inflate() is called again, the same case is attempted again, and |
512 | if the appropriate resources are provided, the machine proceeds to the |
513 | next state. The NEEDBITS() macro is usually the way the state evaluates |
514 | whether it can proceed or should return. NEEDBITS() does the return if |
515 | the requested bits are not available. The typical use of the BITS macros |
516 | is: |
517 | |
518 | NEEDBITS(n); |
519 | ... do something with BITS(n) ... |
520 | DROPBITS(n); |
521 | |
522 | where NEEDBITS(n) either returns from inflate() if there isn't enough |
523 | input left to load n bits into the accumulator, or it continues. BITS(n) |
524 | gives the low n bits in the accumulator. When done, DROPBITS(n) drops |
525 | the low n bits off the accumulator. INITBITS() clears the accumulator |
526 | and sets the number of available bits to zero. BYTEBITS() discards just |
527 | enough bits to put the accumulator on a byte boundary. After BYTEBITS() |
528 | and a NEEDBITS(8), then BITS(8) would return the next byte in the stream. |
529 | |
530 | NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return |
531 | if there is no input available. The decoding of variable length codes uses |
532 | PULLBYTE() directly in order to pull just enough bytes to decode the next |
533 | code, and no more. |
534 | |
535 | Some states loop until they get enough input, making sure that enough |
536 | state information is maintained to continue the loop where it left off |
537 | if NEEDBITS() returns in the loop. For example, want, need, and keep |
538 | would all have to actually be part of the saved state in case NEEDBITS() |
539 | returns: |
540 | |
541 | case STATEw: |
542 | while (want < need) { |
543 | NEEDBITS(n); |
544 | keep[want++] = BITS(n); |
545 | DROPBITS(n); |
546 | } |
547 | state = STATEx; |
548 | case STATEx: |
549 | |
550 | As shown above, if the next state is also the next case, then the break |
551 | is omitted. |
552 | |
553 | A state may also return if there is not enough output space available to |
554 | complete that state. Those states are copying stored data, writing a |
555 | literal byte, and copying a matching string. |
556 | |
557 | When returning, a "goto inf_leave" is used to update the total counters, |
558 | update the check value, and determine whether any progress has been made |
559 | during that inflate() call in order to return the proper return code. |
560 | Progress is defined as a change in either strm->avail_in or strm->avail_out. |
561 | When there is a window, goto inf_leave will update the window with the last |
562 | output written. If a goto inf_leave occurs in the middle of decompression |
563 | and there is no window currently, goto inf_leave will create one and copy |
564 | output to the window for the next call of inflate(). |
565 | |
566 | In this implementation, the flush parameter of inflate() only affects the |
567 | return code (per zlib.h). inflate() always writes as much as possible to |
568 | strm->next_out, given the space available and the provided input--the effect |
569 | documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers |
570 | the allocation of and copying into a sliding window until necessary, which |
571 | provides the effect documented in zlib.h for Z_FINISH when the entire input |
572 | stream available. So the only thing the flush parameter actually does is: |
573 | when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it |
574 | will return Z_BUF_ERROR if it has not reached the end of the stream. |
575 | */ |
576 | |
577 | int ZEXPORT |
578 | inflate(z_streamp strm, int flush) |
579 | { |
580 | struct inflate_state FAR *state; |
581 | unsigned char FAR *next; /* next input */ |
582 | unsigned char FAR *put; /* next output */ |
583 | unsigned have, left; /* available input and output */ |
584 | unsigned long hold; /* bit buffer */ |
585 | unsigned bits; /* bits in bit buffer */ |
586 | unsigned in, out; /* save starting available input and output */ |
587 | unsigned copy; /* number of stored or match bytes to copy */ |
588 | unsigned char FAR *from; /* where to copy match bytes from */ |
589 | code this; /* current decoding table entry */ |
590 | code last; /* parent table entry */ |
591 | unsigned len; /* length to copy for repeats, bits to drop */ |
592 | int ret; /* return code */ |
593 | #ifdef GUNZIP |
594 | unsigned char hbuf[4]; /* buffer for gzip header crc calculation */ |
595 | #endif |
596 | static const unsigned short order[19] = /* permutation of code lengths */ |
597 | {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; |
598 | |
599 | if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL || |
600 | (strm->next_in == Z_NULL && strm->avail_in != 0)) |
601 | return Z_STREAM_ERROR; |
602 | |
603 | state = (struct inflate_state FAR *)strm->state; |
604 | if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */ |
605 | LOAD(); |
606 | in = have; |
607 | out = left; |
608 | ret = Z_OK; |
609 | for (;;) |
610 | switch (state->mode) { |
611 | case HEAD: |
612 | if (state->wrap == 0) { |
613 | state->mode = TYPEDO; |
614 | break; |
615 | } |
616 | NEEDBITS(16); |
617 | #ifdef GUNZIP |
618 | if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */ |
619 | state->check = z_crc32(0L, Z_NULL, 0); |
620 | CRC2(state->check, hold); |
621 | INITBITS(); |
622 | state->mode = FLAGS; |
623 | break; |
624 | } |
625 | state->flags = 0; /* expect zlib header */ |
626 | if (state->head != Z_NULL) |
627 | state->head->done = -1; |
628 | if (!(state->wrap & 1) || /* check if zlib header allowed */ |
629 | #else |
630 | if ( |
631 | #endif |
632 | ((BITS(8) << 8) + (hold >> 8)) % 31) { |
633 | strm->msg = (char *)"incorrect header check" ; |
634 | state->mode = BAD; |
635 | break; |
636 | } |
637 | if (BITS(4) != Z_DEFLATED) { |
638 | strm->msg = (char *)"unknown compression method" ; |
639 | state->mode = BAD; |
640 | break; |
641 | } |
642 | DROPBITS(4); |
643 | len = BITS(4) + 8; |
644 | if (len > state->wbits) { |
645 | strm->msg = (char *)"invalid window size" ; |
646 | state->mode = BAD; |
647 | break; |
648 | } |
649 | state->dmax = 1U << len; |
650 | Tracev((stderr, "inflate: zlib header ok\n" )); |
651 | strm->adler = state->check = adler32(0L, Z_NULL, 0); |
652 | state->mode = hold & 0x200 ? DICTID : TYPE; |
653 | INITBITS(); |
654 | break; |
655 | #ifdef GUNZIP |
656 | case FLAGS: |
657 | NEEDBITS(16); |
658 | state->flags = (int)(hold); |
659 | if ((state->flags & 0xff) != Z_DEFLATED) { |
660 | strm->msg = (char *)"unknown compression method" ; |
661 | state->mode = BAD; |
662 | break; |
663 | } |
664 | if (state->flags & 0xe000) { |
665 | strm->msg = (char *)"unknown header flags set" ; |
666 | state->mode = BAD; |
667 | break; |
668 | } |
669 | if (state->head != Z_NULL) |
670 | state->head->text = (int)((hold >> 8) & 1); |
671 | if (state->flags & 0x0200) CRC2(state->check, hold); |
672 | INITBITS(); |
673 | state->mode = TIME; |
674 | case TIME: |
675 | NEEDBITS(32); |
676 | if (state->head != Z_NULL) |
677 | state->head->time = hold; |
678 | if (state->flags & 0x0200) CRC4(state->check, hold); |
679 | INITBITS(); |
680 | state->mode = OS; |
681 | case OS: |
682 | NEEDBITS(16); |
683 | if (state->head != Z_NULL) { |
684 | state->head->xflags = (int)(hold & 0xff); |
685 | state->head->os = (int)(hold >> 8); |
686 | } |
687 | if (state->flags & 0x0200) CRC2(state->check, hold); |
688 | INITBITS(); |
689 | state->mode = EXLEN; |
690 | case EXLEN: |
691 | if (state->flags & 0x0400) { |
692 | NEEDBITS(16); |
693 | state->length = (unsigned)(hold); |
694 | if (state->head != Z_NULL) |
695 | state->head->extra_len = (unsigned)hold; |
696 | if (state->flags & 0x0200) CRC2(state->check, hold); |
697 | INITBITS(); |
698 | } |
699 | else if (state->head != Z_NULL) |
700 | state->head->extra = Z_NULL; |
701 | state->mode = EXTRA; |
702 | case EXTRA: |
703 | if (state->flags & 0x0400) { |
704 | copy = state->length; |
705 | if (copy > have) copy = have; |
706 | if (copy) { |
707 | if (state->head != Z_NULL && |
708 | state->head->extra != Z_NULL) { |
709 | len = state->head->extra_len - state->length; |
710 | zmemcpy(state->head->extra + len, next, |
711 | len + copy > state->head->extra_max ? |
712 | state->head->extra_max - len : copy); |
713 | } |
714 | if (state->flags & 0x0200) |
715 | state->check = z_crc32(state->check, next, copy); |
716 | have -= copy; |
717 | next += copy; |
718 | state->length -= copy; |
719 | } |
720 | if (state->length) goto inf_leave; |
721 | } |
722 | state->length = 0; |
723 | state->mode = NAME; |
724 | case NAME: |
725 | if (state->flags & 0x0800) { |
726 | if (have == 0) goto inf_leave; |
727 | copy = 0; |
728 | do { |
729 | len = (unsigned)(next[copy++]); |
730 | if (state->head != Z_NULL && |
731 | state->head->name != Z_NULL && |
732 | state->length < state->head->name_max) |
733 | state->head->name[state->length++] = len; |
734 | } while (len && copy < have); |
735 | if (state->flags & 0x0200) |
736 | state->check = z_crc32(state->check, next, copy); |
737 | have -= copy; |
738 | next += copy; |
739 | if (len) goto inf_leave; |
740 | } |
741 | else if (state->head != Z_NULL) |
742 | state->head->name = Z_NULL; |
743 | state->length = 0; |
744 | state->mode = COMMENT; |
745 | case COMMENT: |
746 | if (state->flags & 0x1000) { |
747 | if (have == 0) goto inf_leave; |
748 | copy = 0; |
749 | do { |
750 | len = (unsigned)(next[copy++]); |
751 | if (state->head != Z_NULL && |
752 | state->head->comment != Z_NULL && |
753 | state->length < state->head->comm_max) |
754 | state->head->comment[state->length++] = len; |
755 | } while (len && copy < have); |
756 | if (state->flags & 0x0200) |
757 | state->check = z_crc32(state->check, next, copy); |
758 | have -= copy; |
759 | next += copy; |
760 | if (len) goto inf_leave; |
761 | } |
762 | else if (state->head != Z_NULL) |
763 | state->head->comment = Z_NULL; |
764 | state->mode = HCRC; |
765 | case HCRC: |
766 | if (state->flags & 0x0200) { |
767 | NEEDBITS(16); |
768 | if (hold != (state->check & 0xffff)) { |
769 | strm->msg = (char *)"header crc mismatch" ; |
770 | state->mode = BAD; |
771 | break; |
772 | } |
773 | INITBITS(); |
774 | } |
775 | if (state->head != Z_NULL) { |
776 | state->head->hcrc = (int)((state->flags >> 9) & 1); |
777 | state->head->done = 1; |
778 | } |
779 | strm->adler = state->check = z_crc32(0L, Z_NULL, 0); |
780 | state->mode = TYPE; |
781 | break; |
782 | #endif |
783 | case DICTID: |
784 | NEEDBITS(32); |
785 | strm->adler = state->check = REVERSE(hold); |
786 | INITBITS(); |
787 | state->mode = DICT; |
788 | case DICT: |
789 | if (state->havedict == 0) { |
790 | RESTORE(); |
791 | return Z_NEED_DICT; |
792 | } |
793 | strm->adler = state->check = adler32(0L, Z_NULL, 0); |
794 | state->mode = TYPE; |
795 | case TYPE: |
796 | if (flush == Z_BLOCK) goto inf_leave; |
797 | case TYPEDO: |
798 | if (state->last) { |
799 | BYTEBITS(); |
800 | state->mode = CHECK; |
801 | break; |
802 | } |
803 | NEEDBITS(3); |
804 | state->last = BITS(1); |
805 | DROPBITS(1); |
806 | switch (BITS(2)) { |
807 | case 0: /* stored block */ |
808 | Tracev((stderr, "inflate: stored block%s\n" , |
809 | state->last ? " (last)" : "" )); |
810 | state->mode = STORED; |
811 | break; |
812 | case 1: /* fixed block */ |
813 | fixedtables(state); |
814 | Tracev((stderr, "inflate: fixed codes block%s\n" , |
815 | state->last ? " (last)" : "" )); |
816 | state->mode = LEN; /* decode codes */ |
817 | break; |
818 | case 2: /* dynamic block */ |
819 | Tracev((stderr, "inflate: dynamic codes block%s\n" , |
820 | state->last ? " (last)" : "" )); |
821 | state->mode = TABLE; |
822 | break; |
823 | case 3: |
824 | strm->msg = (char *)"invalid block type" ; |
825 | state->mode = BAD; |
826 | } |
827 | DROPBITS(2); |
828 | break; |
829 | case STORED: |
830 | BYTEBITS(); /* go to byte boundary */ |
831 | NEEDBITS(32); |
832 | if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { |
833 | strm->msg = (char *)"invalid stored block lengths" ; |
834 | state->mode = BAD; |
835 | break; |
836 | } |
837 | state->length = (unsigned)hold & 0xffff; |
838 | Tracev((stderr, "inflate: stored length %u\n" , |
839 | state->length)); |
840 | INITBITS(); |
841 | state->mode = COPY; |
842 | case COPY: |
843 | copy = state->length; |
844 | if (copy) { |
845 | if (copy > have) copy = have; |
846 | if (copy > left) copy = left; |
847 | if (copy == 0) goto inf_leave; |
848 | zmemcpy(put, next, copy); |
849 | have -= copy; |
850 | next += copy; |
851 | left -= copy; |
852 | put += copy; |
853 | state->length -= copy; |
854 | break; |
855 | } |
856 | Tracev((stderr, "inflate: stored end\n" )); |
857 | state->mode = TYPE; |
858 | break; |
859 | case TABLE: |
860 | NEEDBITS(14); |
861 | state->nlen = BITS(5) + 257; |
862 | DROPBITS(5); |
863 | state->ndist = BITS(5) + 1; |
864 | DROPBITS(5); |
865 | state->ncode = BITS(4) + 4; |
866 | DROPBITS(4); |
867 | #ifndef PKZIP_BUG_WORKAROUND |
868 | if (state->nlen > 286 || state->ndist > 30) { |
869 | strm->msg = (char *)"too many length or distance symbols" ; |
870 | state->mode = BAD; |
871 | break; |
872 | } |
873 | #endif |
874 | Tracev((stderr, "inflate: table sizes ok\n" )); |
875 | state->have = 0; |
876 | state->mode = LENLENS; |
877 | case LENLENS: |
878 | while (state->have < state->ncode) { |
879 | NEEDBITS(3); |
880 | state->lens[order[state->have++]] = (unsigned short)BITS(3); |
881 | DROPBITS(3); |
882 | } |
883 | while (state->have < 19) |
884 | state->lens[order[state->have++]] = 0; |
885 | state->next = state->codes; |
886 | state->lencode = (code const FAR *)(state->next); |
887 | state->lenbits = 7; |
888 | ret = inflate_table(CODES, state->lens, 19, &(state->next), |
889 | &(state->lenbits), state->work); |
890 | if (ret) { |
891 | strm->msg = (char *)"invalid code lengths set" ; |
892 | state->mode = BAD; |
893 | break; |
894 | } |
895 | Tracev((stderr, "inflate: code lengths ok\n" )); |
896 | state->have = 0; |
897 | state->mode = CODELENS; |
898 | case CODELENS: |
899 | while (state->have < state->nlen + state->ndist) { |
900 | for (;;) { |
901 | this = state->lencode[BITS(state->lenbits)]; |
902 | if ((unsigned)(this.bits) <= bits) break; |
903 | PULLBYTE(); |
904 | } |
905 | if (this.val < 16) { |
906 | NEEDBITS(this.bits); |
907 | DROPBITS(this.bits); |
908 | state->lens[state->have++] = this.val; |
909 | } |
910 | else { |
911 | if (this.val == 16) { |
912 | NEEDBITS(this.bits + 2); |
913 | DROPBITS(this.bits); |
914 | if (state->have == 0) { |
915 | strm->msg = (char *)"invalid bit length repeat" ; |
916 | state->mode = BAD; |
917 | break; |
918 | } |
919 | len = state->lens[state->have - 1]; |
920 | copy = 3 + BITS(2); |
921 | DROPBITS(2); |
922 | } |
923 | else if (this.val == 17) { |
924 | NEEDBITS(this.bits + 3); |
925 | DROPBITS(this.bits); |
926 | len = 0; |
927 | copy = 3 + BITS(3); |
928 | DROPBITS(3); |
929 | } |
930 | else { |
931 | NEEDBITS(this.bits + 7); |
932 | DROPBITS(this.bits); |
933 | len = 0; |
934 | copy = 11 + BITS(7); |
935 | DROPBITS(7); |
936 | } |
937 | if (state->have + copy > state->nlen + state->ndist) { |
938 | strm->msg = (char *)"invalid bit length repeat" ; |
939 | state->mode = BAD; |
940 | break; |
941 | } |
942 | while (copy--) |
943 | state->lens[state->have++] = (unsigned short)len; |
944 | } |
945 | } |
946 | |
947 | /* handle error breaks in while */ |
948 | if (state->mode == BAD) break; |
949 | |
950 | /* build code tables */ |
951 | state->next = state->codes; |
952 | state->lencode = (code const FAR *)(state->next); |
953 | state->lenbits = 9; |
954 | ret = inflate_table(LENS, state->lens, state->nlen, &(state->next), |
955 | &(state->lenbits), state->work); |
956 | if (ret) { |
957 | strm->msg = (char *)"invalid literal/lengths set" ; |
958 | state->mode = BAD; |
959 | break; |
960 | } |
961 | state->distcode = (code const FAR *)(state->next); |
962 | state->distbits = 6; |
963 | ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist, |
964 | &(state->next), &(state->distbits), state->work); |
965 | if (ret) { |
966 | strm->msg = (char *)"invalid distances set" ; |
967 | state->mode = BAD; |
968 | break; |
969 | } |
970 | Tracev((stderr, "inflate: codes ok\n" )); |
971 | state->mode = LEN; |
972 | case LEN: |
973 | if (have >= 6 && left >= 258) { |
974 | RESTORE(); |
975 | inflate_fast(strm, out); |
976 | LOAD(); |
977 | break; |
978 | } |
979 | for (;;) { |
980 | this = state->lencode[BITS(state->lenbits)]; |
981 | if ((unsigned)(this.bits) <= bits) break; |
982 | PULLBYTE(); |
983 | } |
984 | if (this.op && (this.op & 0xf0) == 0) { |
985 | last = this; |
986 | for (;;) { |
987 | this = state->lencode[last.val + |
988 | (BITS(last.bits + last.op) >> last.bits)]; |
989 | if ((unsigned)(last.bits + this.bits) <= bits) break; |
990 | PULLBYTE(); |
991 | } |
992 | DROPBITS(last.bits); |
993 | } |
994 | DROPBITS(this.bits); |
995 | state->length = (unsigned)this.val; |
996 | if ((int)(this.op) == 0) { |
997 | Tracevv((stderr, this.val >= 0x20 && this.val < 0x7f ? |
998 | "inflate: literal '%c'\n" : |
999 | "inflate: literal 0x%02x\n" , this.val)); |
1000 | state->mode = LIT; |
1001 | break; |
1002 | } |
1003 | if (this.op & 32) { |
1004 | Tracevv((stderr, "inflate: end of block\n" )); |
1005 | state->mode = TYPE; |
1006 | break; |
1007 | } |
1008 | if (this.op & 64) { |
1009 | strm->msg = (char *)"invalid literal/length code" ; |
1010 | state->mode = BAD; |
1011 | break; |
1012 | } |
1013 | state->extra = (unsigned)(this.op) & 15; |
1014 | state->mode = LENEXT; |
1015 | case LENEXT: |
1016 | if (state->extra) { |
1017 | NEEDBITS(state->extra); |
1018 | state->length += BITS(state->extra); |
1019 | DROPBITS(state->extra); |
1020 | } |
1021 | Tracevv((stderr, "inflate: length %u\n" , state->length)); |
1022 | state->mode = DIST; |
1023 | case DIST: |
1024 | for (;;) { |
1025 | this = state->distcode[BITS(state->distbits)]; |
1026 | if ((unsigned)(this.bits) <= bits) break; |
1027 | PULLBYTE(); |
1028 | } |
1029 | if ((this.op & 0xf0) == 0) { |
1030 | last = this; |
1031 | for (;;) { |
1032 | this = state->distcode[last.val + |
1033 | (BITS(last.bits + last.op) >> last.bits)]; |
1034 | if ((unsigned)(last.bits + this.bits) <= bits) break; |
1035 | PULLBYTE(); |
1036 | } |
1037 | DROPBITS(last.bits); |
1038 | } |
1039 | DROPBITS(this.bits); |
1040 | if (this.op & 64) { |
1041 | strm->msg = (char *)"invalid distance code" ; |
1042 | state->mode = BAD; |
1043 | break; |
1044 | } |
1045 | state->offset = (unsigned)this.val; |
1046 | state->extra = (unsigned)(this.op) & 15; |
1047 | state->mode = DISTEXT; |
1048 | case DISTEXT: |
1049 | if (state->extra) { |
1050 | NEEDBITS(state->extra); |
1051 | state->offset += BITS(state->extra); |
1052 | DROPBITS(state->extra); |
1053 | } |
1054 | #ifdef INFLATE_STRICT |
1055 | if (state->offset > state->dmax) { |
1056 | strm->msg = (char *)"invalid distance too far back" ; |
1057 | state->mode = BAD; |
1058 | break; |
1059 | } |
1060 | #endif |
1061 | if (state->offset > state->whave + out - left) { |
1062 | strm->msg = (char *)"invalid distance too far back" ; |
1063 | state->mode = BAD; |
1064 | break; |
1065 | } |
1066 | Tracevv((stderr, "inflate: distance %u\n" , state->offset)); |
1067 | state->mode = MATCH; |
1068 | case MATCH: |
1069 | if (left == 0) goto inf_leave; |
1070 | copy = out - left; |
1071 | if (state->offset > copy) { /* copy from window */ |
1072 | copy = state->offset - copy; |
1073 | if (copy > state->write) { |
1074 | copy -= state->write; |
1075 | from = state->window + (state->wsize - copy); |
1076 | } |
1077 | else |
1078 | from = state->window + (state->write - copy); |
1079 | if (copy > state->length) copy = state->length; |
1080 | } |
1081 | else { /* copy from output */ |
1082 | from = put - state->offset; |
1083 | copy = state->length; |
1084 | } |
1085 | if (copy > left) copy = left; |
1086 | left -= copy; |
1087 | state->length -= copy; |
1088 | do { |
1089 | *put++ = *from++; |
1090 | } while (--copy); |
1091 | if (state->length == 0) state->mode = LEN; |
1092 | break; |
1093 | case LIT: |
1094 | if (left == 0) goto inf_leave; |
1095 | *put++ = (unsigned char)(state->length); |
1096 | left--; |
1097 | state->mode = LEN; |
1098 | break; |
1099 | case CHECK: |
1100 | if (state->wrap) { |
1101 | NEEDBITS(32); |
1102 | out -= left; |
1103 | strm->total_out += out; |
1104 | state->total += out; |
1105 | if (out) |
1106 | strm->adler = state->check = |
1107 | UPDATE(state->check, put - out, out); |
1108 | out = left; |
1109 | if (( |
1110 | #ifdef GUNZIP |
1111 | state->flags ? hold : |
1112 | #endif |
1113 | REVERSE(hold)) != state->check) { |
1114 | strm->msg = (char *)"incorrect data check" ; |
1115 | state->mode = BAD; |
1116 | break; |
1117 | } |
1118 | INITBITS(); |
1119 | Tracev((stderr, "inflate: check matches trailer\n" )); |
1120 | } |
1121 | #ifdef GUNZIP |
1122 | state->mode = LENGTH; |
1123 | case LENGTH: |
1124 | if (state->wrap && state->flags) { |
1125 | NEEDBITS(32); |
1126 | if (hold != (state->total & 0xffffffffUL)) { |
1127 | strm->msg = (char *)"incorrect length check" ; |
1128 | state->mode = BAD; |
1129 | break; |
1130 | } |
1131 | INITBITS(); |
1132 | Tracev((stderr, "inflate: length matches trailer\n" )); |
1133 | } |
1134 | #endif |
1135 | state->mode = DONE; |
1136 | case DONE: |
1137 | ret = Z_STREAM_END; |
1138 | goto inf_leave; |
1139 | case BAD: |
1140 | ret = Z_DATA_ERROR; |
1141 | goto inf_leave; |
1142 | case MEM: |
1143 | return Z_MEM_ERROR; |
1144 | case SYNC: |
1145 | default: |
1146 | return Z_STREAM_ERROR; |
1147 | } |
1148 | |
1149 | /* |
1150 | Return from inflate(), updating the total counts and the check value. |
1151 | If there was no progress during the inflate() call, return a buffer |
1152 | error. Call updatewindow() to create and/or update the window state. |
1153 | Note: a memory error from inflate() is non-recoverable. |
1154 | */ |
1155 | inf_leave: |
1156 | RESTORE(); |
1157 | if (state->wsize || (state->mode < CHECK && out != strm->avail_out)) |
1158 | if (updatewindow(strm, out)) { |
1159 | state->mode = MEM; |
1160 | return Z_MEM_ERROR; |
1161 | } |
1162 | in -= strm->avail_in; |
1163 | out -= strm->avail_out; |
1164 | strm->total_in += in; |
1165 | strm->total_out += out; |
1166 | state->total += out; |
1167 | if (state->wrap && out) |
1168 | strm->adler = state->check = |
1169 | UPDATE(state->check, strm->next_out - out, out); |
1170 | strm->data_type = state->bits + (state->last ? 64 : 0) + |
1171 | (state->mode == TYPE ? 128 : 0); |
1172 | if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK) |
1173 | ret = Z_BUF_ERROR; |
1174 | return ret; |
1175 | } |
1176 | |
1177 | int ZEXPORT |
1178 | inflateEnd(z_streamp strm) |
1179 | { |
1180 | struct inflate_state FAR *state; |
1181 | if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0) |
1182 | return Z_STREAM_ERROR; |
1183 | state = (struct inflate_state FAR *)strm->state; |
1184 | if (state->window != Z_NULL) ZFREE(strm, state->window); |
1185 | ZFREE(strm, strm->state); |
1186 | strm->state = Z_NULL; |
1187 | Tracev((stderr, "inflate: end\n" )); |
1188 | return Z_OK; |
1189 | } |
1190 | |
1191 | int ZEXPORT |
1192 | inflateSetDictionary(z_streamp strm, const Bytef *dictionary, uInt dictLength) |
1193 | { |
1194 | struct inflate_state FAR *state; |
1195 | unsigned long id; |
1196 | |
1197 | /* check state */ |
1198 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
1199 | state = (struct inflate_state FAR *)strm->state; |
1200 | if (state->wrap != 0 && state->mode != DICT) |
1201 | return Z_STREAM_ERROR; |
1202 | |
1203 | /* check for correct dictionary id */ |
1204 | if (state->mode == DICT) { |
1205 | id = adler32(0L, Z_NULL, 0); |
1206 | id = adler32(id, dictionary, dictLength); |
1207 | if (id != state->check) |
1208 | return Z_DATA_ERROR; |
1209 | } |
1210 | |
1211 | /* copy dictionary to window */ |
1212 | if (updatewindow(strm, strm->avail_out)) { |
1213 | state->mode = MEM; |
1214 | return Z_MEM_ERROR; |
1215 | } |
1216 | if (dictLength > state->wsize) { |
1217 | zmemcpy(state->window, dictionary + dictLength - state->wsize, |
1218 | state->wsize); |
1219 | state->whave = state->wsize; |
1220 | } |
1221 | else { |
1222 | zmemcpy(state->window + state->wsize - dictLength, dictionary, |
1223 | dictLength); |
1224 | state->whave = dictLength; |
1225 | } |
1226 | state->havedict = 1; |
1227 | Tracev((stderr, "inflate: dictionary set\n" )); |
1228 | return Z_OK; |
1229 | } |
1230 | |
1231 | int ZEXPORT |
1232 | (z_streamp strm, gz_headerp head) |
1233 | { |
1234 | struct inflate_state FAR *state; |
1235 | |
1236 | /* check state */ |
1237 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
1238 | state = (struct inflate_state FAR *)strm->state; |
1239 | if ((state->wrap & 2) == 0) return Z_STREAM_ERROR; |
1240 | |
1241 | /* save header structure */ |
1242 | state->head = head; |
1243 | head->done = 0; |
1244 | return Z_OK; |
1245 | } |
1246 | |
1247 | /* |
1248 | Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found |
1249 | or when out of input. When called, *have is the number of pattern bytes |
1250 | found in order so far, in 0..3. On return *have is updated to the new |
1251 | state. If on return *have equals four, then the pattern was found and the |
1252 | return value is how many bytes were read including the last byte of the |
1253 | pattern. If *have is less than four, then the pattern has not been found |
1254 | yet and the return value is len. In the latter case, syncsearch() can be |
1255 | called again with more data and the *have state. *have is initialized to |
1256 | zero for the first call. |
1257 | */ |
1258 | local unsigned |
1259 | syncsearch(unsigned FAR *have, unsigned char FAR *buf, unsigned len) |
1260 | { |
1261 | unsigned got; |
1262 | unsigned next; |
1263 | |
1264 | got = *have; |
1265 | next = 0; |
1266 | while (next < len && got < 4) { |
1267 | if ((int)(buf[next]) == (got < 2 ? 0 : 0xff)) |
1268 | got++; |
1269 | else if (buf[next]) |
1270 | got = 0; |
1271 | else |
1272 | got = 4 - got; |
1273 | next++; |
1274 | } |
1275 | *have = got; |
1276 | return next; |
1277 | } |
1278 | |
1279 | int ZEXPORT |
1280 | inflateSync(z_streamp strm) |
1281 | { |
1282 | unsigned len; /* number of bytes to look at or looked at */ |
1283 | unsigned long in, out; /* temporary to save total_in and total_out */ |
1284 | unsigned char buf[4]; /* to restore bit buffer to byte string */ |
1285 | struct inflate_state FAR *state; |
1286 | |
1287 | /* check parameters */ |
1288 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
1289 | state = (struct inflate_state FAR *)strm->state; |
1290 | if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR; |
1291 | |
1292 | /* if first time, start search in bit buffer */ |
1293 | if (state->mode != SYNC) { |
1294 | state->mode = SYNC; |
1295 | state->hold <<= state->bits & 7; |
1296 | state->bits -= state->bits & 7; |
1297 | len = 0; |
1298 | while (state->bits >= 8) { |
1299 | buf[len++] = (unsigned char)(state->hold); |
1300 | state->hold >>= 8; |
1301 | state->bits -= 8; |
1302 | } |
1303 | state->have = 0; |
1304 | syncsearch(&(state->have), buf, len); |
1305 | } |
1306 | |
1307 | /* search available input */ |
1308 | len = syncsearch(&(state->have), strm->next_in, strm->avail_in); |
1309 | strm->avail_in -= len; |
1310 | strm->next_in += len; |
1311 | strm->total_in += len; |
1312 | |
1313 | /* return no joy or set up to restart inflate() on a new block */ |
1314 | if (state->have != 4) return Z_DATA_ERROR; |
1315 | in = strm->total_in; out = strm->total_out; |
1316 | inflateReset(strm); |
1317 | strm->total_in = in; strm->total_out = out; |
1318 | state->mode = TYPE; |
1319 | return Z_OK; |
1320 | } |
1321 | |
1322 | /* |
1323 | Returns true if inflate is currently at the end of a block generated by |
1324 | Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP |
1325 | implementation to provide an additional safety check. PPP uses |
1326 | Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored |
1327 | block. When decompressing, PPP checks that at the end of input packet, |
1328 | inflate is waiting for these length bytes. |
1329 | */ |
1330 | int ZEXPORT |
1331 | inflateSyncPoint(z_streamp strm) |
1332 | { |
1333 | struct inflate_state FAR *state; |
1334 | |
1335 | if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
1336 | state = (struct inflate_state FAR *)strm->state; |
1337 | return state->mode == STORED && state->bits == 0; |
1338 | } |
1339 | |
1340 | int ZEXPORT |
1341 | inflateCopy(z_streamp dest, z_streamp source) |
1342 | { |
1343 | struct inflate_state FAR *state; |
1344 | struct inflate_state FAR *copy; |
1345 | unsigned char FAR *window; |
1346 | unsigned wsize; |
1347 | |
1348 | /* check input */ |
1349 | if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL || |
1350 | source->zalloc == (alloc_func)0 || source->zfree == (free_func)0) |
1351 | return Z_STREAM_ERROR; |
1352 | state = (struct inflate_state FAR *)source->state; |
1353 | |
1354 | /* allocate space */ |
1355 | copy = (struct inflate_state FAR *) |
1356 | ZALLOC(source, 1, sizeof(struct inflate_state)); |
1357 | if (copy == Z_NULL) return Z_MEM_ERROR; |
1358 | window = Z_NULL; |
1359 | if (state->window != Z_NULL) { |
1360 | window = (unsigned char FAR *) |
1361 | ZALLOC(source, 1U << state->wbits, sizeof(unsigned char)); |
1362 | if (window == Z_NULL) { |
1363 | ZFREE(source, copy); |
1364 | return Z_MEM_ERROR; |
1365 | } |
1366 | } |
1367 | |
1368 | /* copy state */ |
1369 | zmemcpy(dest, source, sizeof(z_stream)); |
1370 | zmemcpy(copy, state, sizeof(struct inflate_state)); |
1371 | if (state->lencode >= state->codes && |
1372 | state->lencode <= state->codes + ENOUGH - 1) { |
1373 | copy->lencode = copy->codes + (state->lencode - state->codes); |
1374 | copy->distcode = copy->codes + (state->distcode - state->codes); |
1375 | } |
1376 | copy->next = copy->codes + (state->next - state->codes); |
1377 | if (window != Z_NULL) { |
1378 | wsize = 1U << state->wbits; |
1379 | zmemcpy(window, state->window, wsize); |
1380 | } |
1381 | copy->window = window; |
1382 | dest->state = (struct internal_state FAR *)copy; |
1383 | return Z_OK; |
1384 | } |
1385 | |