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87a2b23a 1/* inflate.c -- zlib decompression
1e5dce21 2 * Copyright (C) 1995-2016 Mark Adler
87a2b23a 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
1f54c5b6 48 * - Pull out common wnext == 0 case for speed in inflate_fast()
87a2b23a 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.
d8b6dda4 81 */
82
83#include "zutil.h"
87a2b23a 84#include "inftrees.h"
85#include "inflate.h"
86#include "inffast.h"
d8b6dda4 87
87a2b23a 88#ifdef MAKEFIXED
89# ifndef BUILDFIXED
90# define BUILDFIXED
91# endif
92#endif
93
94/* function prototypes */
1e5dce21 95local int inflateStateCheck OF((z_streamp strm));
87a2b23a 96local void fixedtables OF((struct inflate_state FAR *state));
4b57a6ef 97local int updatewindow OF((z_streamp strm, const unsigned char FAR *end,
98 unsigned copy));
87a2b23a 99#ifdef BUILDFIXED
100 void makefixed OF((void));
101#endif
4b57a6ef 102local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf,
87a2b23a 103 unsigned len));
d8b6dda4 104
1e5dce21 105local int inflateStateCheck(strm)
106z_streamp strm;
107{
108 struct inflate_state FAR *state;
109 if (strm == Z_NULL ||
110 strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
111 return 1;
112 state = (struct inflate_state FAR *)strm->state;
113 if (state == Z_NULL || state->strm != strm ||
114 state->mode < HEAD || state->mode > SYNC)
115 return 1;
116 return 0;
117}
118
75e1829f 119int ZEXPORT inflateResetKeep(strm)
87a2b23a 120z_streamp strm;
d8b6dda4 121{
87a2b23a 122 struct inflate_state FAR *state;
d8b6dda4 123
1e5dce21 124 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
87a2b23a 125 state = (struct inflate_state FAR *)strm->state;
126 strm->total_in = strm->total_out = state->total = 0;
127 strm->msg = Z_NULL;
75e1829f 128 if (state->wrap) /* to support ill-conceived Java test suite */
129 strm->adler = state->wrap & 1;
87a2b23a 130 state->mode = HEAD;
131 state->last = 0;
132 state->havedict = 0;
d919a5db 133 state->dmax = 32768U;
134 state->head = Z_NULL;
87a2b23a 135 state->hold = 0;
136 state->bits = 0;
137 state->lencode = state->distcode = state->next = state->codes;
1f54c5b6 138 state->sane = 1;
139 state->back = -1;
87a2b23a 140 Tracev((stderr, "inflate: reset\n"));
141 return Z_OK;
142}
d8b6dda4 143
75e1829f 144int ZEXPORT inflateReset(strm)
145z_streamp strm;
146{
147 struct inflate_state FAR *state;
148
1e5dce21 149 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
75e1829f 150 state = (struct inflate_state FAR *)strm->state;
151 state->wsize = 0;
152 state->whave = 0;
153 state->wnext = 0;
154 return inflateResetKeep(strm);
155}
156
1f54c5b6 157int ZEXPORT inflateReset2(strm, windowBits)
d919a5db 158z_streamp strm;
1f54c5b6 159int windowBits;
d919a5db 160{
1f54c5b6 161 int wrap;
d919a5db 162 struct inflate_state FAR *state;
163
1f54c5b6 164 /* get the state */
1e5dce21 165 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
d919a5db 166 state = (struct inflate_state FAR *)strm->state;
1f54c5b6 167
168 /* extract wrap request from windowBits parameter */
169 if (windowBits < 0) {
170 wrap = 0;
171 windowBits = -windowBits;
172 }
173 else {
1e5dce21 174 wrap = (windowBits >> 4) + 5;
1f54c5b6 175#ifdef GUNZIP
176 if (windowBits < 48)
177 windowBits &= 15;
178#endif
179 }
180
181 /* set number of window bits, free window if different */
182 if (windowBits && (windowBits < 8 || windowBits > 15))
183 return Z_STREAM_ERROR;
184 if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
185 ZFREE(strm, state->window);
186 state->window = Z_NULL;
187 }
188
189 /* update state and reset the rest of it */
190 state->wrap = wrap;
191 state->wbits = (unsigned)windowBits;
192 return inflateReset(strm);
d919a5db 193}
194
87a2b23a 195int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
196z_streamp strm;
197int windowBits;
d8b6dda4 198const char *version;
199int stream_size;
200{
1f54c5b6 201 int ret;
87a2b23a 202 struct inflate_state FAR *state;
d8b6dda4 203
87a2b23a 204 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
205 stream_size != (int)(sizeof(z_stream)))
206 return Z_VERSION_ERROR;
207 if (strm == Z_NULL) return Z_STREAM_ERROR;
208 strm->msg = Z_NULL; /* in case we return an error */
209 if (strm->zalloc == (alloc_func)0) {
75e1829f 210#ifdef Z_SOLO
211 return Z_STREAM_ERROR;
212#else
87a2b23a 213 strm->zalloc = zcalloc;
214 strm->opaque = (voidpf)0;
75e1829f 215#endif
87a2b23a 216 }
75e1829f 217 if (strm->zfree == (free_func)0)
218#ifdef Z_SOLO
219 return Z_STREAM_ERROR;
220#else
221 strm->zfree = zcfree;
222#endif
87a2b23a 223 state = (struct inflate_state FAR *)
224 ZALLOC(strm, 1, sizeof(struct inflate_state));
225 if (state == Z_NULL) return Z_MEM_ERROR;
226 Tracev((stderr, "inflate: allocated\n"));
d919a5db 227 strm->state = (struct internal_state FAR *)state;
1e5dce21 228 state->strm = strm;
1f54c5b6 229 state->window = Z_NULL;
1e5dce21 230 state->mode = HEAD; /* to pass state test in inflateReset2() */
1f54c5b6 231 ret = inflateReset2(strm, windowBits);
232 if (ret != Z_OK) {
87a2b23a 233 ZFREE(strm, state);
234 strm->state = Z_NULL;
87a2b23a 235 }
1f54c5b6 236 return ret;
87a2b23a 237}
d8b6dda4 238
87a2b23a 239int ZEXPORT inflateInit_(strm, version, stream_size)
240z_streamp strm;
d8b6dda4 241const char *version;
242int stream_size;
243{
87a2b23a 244 return inflateInit2_(strm, DEF_WBITS, version, stream_size);
245}
246
1f54c5b6 247int ZEXPORT inflatePrime(strm, bits, value)
248z_streamp strm;
249int bits;
250int value;
251{
252 struct inflate_state FAR *state;
253
1e5dce21 254 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1f54c5b6 255 state = (struct inflate_state FAR *)strm->state;
256 if (bits < 0) {
257 state->hold = 0;
258 state->bits = 0;
259 return Z_OK;
260 }
1e5dce21 261 if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR;
1f54c5b6 262 value &= (1L << bits) - 1;
1e5dce21 263 state->hold += (unsigned)value << state->bits;
264 state->bits += (uInt)bits;
1f54c5b6 265 return Z_OK;
266}
267
87a2b23a 268/*
269 Return state with length and distance decoding tables and index sizes set to
270 fixed code decoding. Normally this returns fixed tables from inffixed.h.
271 If BUILDFIXED is defined, then instead this routine builds the tables the
272 first time it's called, and returns those tables the first time and
273 thereafter. This reduces the size of the code by about 2K bytes, in
274 exchange for a little execution time. However, BUILDFIXED should not be
275 used for threaded applications, since the rewriting of the tables and virgin
276 may not be thread-safe.
277 */
278local void fixedtables(state)
279struct inflate_state FAR *state;
280{
281#ifdef BUILDFIXED
282 static int virgin = 1;
283 static code *lenfix, *distfix;
284 static code fixed[544];
285
286 /* build fixed huffman tables if first call (may not be thread safe) */
287 if (virgin) {
288 unsigned sym, bits;
289 static code *next;
290
291 /* literal/length table */
292 sym = 0;
293 while (sym < 144) state->lens[sym++] = 8;
294 while (sym < 256) state->lens[sym++] = 9;
295 while (sym < 280) state->lens[sym++] = 7;
296 while (sym < 288) state->lens[sym++] = 8;
297 next = fixed;
298 lenfix = next;
299 bits = 9;
300 inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
301
302 /* distance table */
303 sym = 0;
304 while (sym < 32) state->lens[sym++] = 5;
305 distfix = next;
306 bits = 5;
307 inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
308
309 /* do this just once */
310 virgin = 0;
311 }
312#else /* !BUILDFIXED */
313# include "inffixed.h"
314#endif /* BUILDFIXED */
315 state->lencode = lenfix;
316 state->lenbits = 9;
317 state->distcode = distfix;
318 state->distbits = 5;
d8b6dda4 319}
320
87a2b23a 321#ifdef MAKEFIXED
322#include <stdio.h>
d8b6dda4 323
87a2b23a 324/*
325 Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also
326 defines BUILDFIXED, so the tables are built on the fly. makefixed() writes
327 those tables to stdout, which would be piped to inffixed.h. A small program
328 can simply call makefixed to do this:
d8b6dda4 329
87a2b23a 330 void makefixed(void);
331
332 int main(void)
333 {
334 makefixed();
335 return 0;
336 }
337
338 Then that can be linked with zlib built with MAKEFIXED defined and run:
339
340 a.out > inffixed.h
341 */
342void makefixed()
d8b6dda4 343{
87a2b23a 344 unsigned low, size;
345 struct inflate_state state;
346
347 fixedtables(&state);
348 puts(" /* inffixed.h -- table for decoding fixed codes");
349 puts(" * Generated automatically by makefixed().");
350 puts(" */");
351 puts("");
352 puts(" /* WARNING: this file should *not* be used by applications.");
353 puts(" It is part of the implementation of this library and is");
354 puts(" subject to change. Applications should only use zlib.h.");
355 puts(" */");
356 puts("");
357 size = 1U << 9;
358 printf(" static const code lenfix[%u] = {", size);
359 low = 0;
360 for (;;) {
361 if ((low % 7) == 0) printf("\n ");
75e1829f 362 printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op,
363 state.lencode[low].bits, state.lencode[low].val);
87a2b23a 364 if (++low == size) break;
365 putchar(',');
366 }
367 puts("\n };");
368 size = 1U << 5;
369 printf("\n static const code distfix[%u] = {", size);
370 low = 0;
371 for (;;) {
372 if ((low % 6) == 0) printf("\n ");
373 printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
374 state.distcode[low].val);
375 if (++low == size) break;
376 putchar(',');
377 }
378 puts("\n };");
379}
380#endif /* MAKEFIXED */
381
382/*
383 Update the window with the last wsize (normally 32K) bytes written before
384 returning. If window does not exist yet, create it. This is only called
385 when a window is already in use, or when output has been written during this
386 inflate call, but the end of the deflate stream has not been reached yet.
387 It is also called to create a window for dictionary data when a dictionary
388 is loaded.
389
390 Providing output buffers larger than 32K to inflate() should provide a speed
391 advantage, since only the last 32K of output is copied to the sliding window
392 upon return from inflate(), and since all distances after the first 32K of
393 output will fall in the output data, making match copies simpler and faster.
394 The advantage may be dependent on the size of the processor's data caches.
395 */
4b57a6ef 396local int updatewindow(strm, end, copy)
87a2b23a 397z_streamp strm;
4b57a6ef 398const Bytef *end;
399unsigned copy;
87a2b23a 400{
401 struct inflate_state FAR *state;
4b57a6ef 402 unsigned dist;
87a2b23a 403
404 state = (struct inflate_state FAR *)strm->state;
405
406 /* if it hasn't been done already, allocate space for the window */
407 if (state->window == Z_NULL) {
408 state->window = (unsigned char FAR *)
409 ZALLOC(strm, 1U << state->wbits,
410 sizeof(unsigned char));
411 if (state->window == Z_NULL) return 1;
412 }
413
414 /* if window not in use yet, initialize */
415 if (state->wsize == 0) {
416 state->wsize = 1U << state->wbits;
1f54c5b6 417 state->wnext = 0;
87a2b23a 418 state->whave = 0;
419 }
420
421 /* copy state->wsize or less output bytes into the circular window */
87a2b23a 422 if (copy >= state->wsize) {
4b57a6ef 423 zmemcpy(state->window, end - state->wsize, state->wsize);
1f54c5b6 424 state->wnext = 0;
87a2b23a 425 state->whave = state->wsize;
426 }
427 else {
1f54c5b6 428 dist = state->wsize - state->wnext;
87a2b23a 429 if (dist > copy) dist = copy;
4b57a6ef 430 zmemcpy(state->window + state->wnext, end - copy, dist);
87a2b23a 431 copy -= dist;
432 if (copy) {
4b57a6ef 433 zmemcpy(state->window, end - copy, copy);
1f54c5b6 434 state->wnext = copy;
87a2b23a 435 state->whave = state->wsize;
436 }
437 else {
1f54c5b6 438 state->wnext += dist;
439 if (state->wnext == state->wsize) state->wnext = 0;
87a2b23a 440 if (state->whave < state->wsize) state->whave += dist;
441 }
442 }
443 return 0;
444}
445
446/* Macros for inflate(): */
447
448/* check function to use adler32() for zlib or crc32() for gzip */
449#ifdef GUNZIP
450# define UPDATE(check, buf, len) \
451 (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
452#else
453# define UPDATE(check, buf, len) adler32(check, buf, len)
454#endif
455
456/* check macros for header crc */
457#ifdef GUNZIP
458# define CRC2(check, word) \
459 do { \
460 hbuf[0] = (unsigned char)(word); \
461 hbuf[1] = (unsigned char)((word) >> 8); \
462 check = crc32(check, hbuf, 2); \
463 } while (0)
464
465# define CRC4(check, word) \
466 do { \
467 hbuf[0] = (unsigned char)(word); \
468 hbuf[1] = (unsigned char)((word) >> 8); \
469 hbuf[2] = (unsigned char)((word) >> 16); \
470 hbuf[3] = (unsigned char)((word) >> 24); \
471 check = crc32(check, hbuf, 4); \
472 } while (0)
473#endif
474
475/* Load registers with state in inflate() for speed */
476#define LOAD() \
477 do { \
478 put = strm->next_out; \
479 left = strm->avail_out; \
480 next = strm->next_in; \
481 have = strm->avail_in; \
482 hold = state->hold; \
483 bits = state->bits; \
484 } while (0)
485
486/* Restore state from registers in inflate() */
487#define RESTORE() \
488 do { \
489 strm->next_out = put; \
490 strm->avail_out = left; \
491 strm->next_in = next; \
492 strm->avail_in = have; \
493 state->hold = hold; \
494 state->bits = bits; \
495 } while (0)
496
497/* Clear the input bit accumulator */
498#define INITBITS() \
499 do { \
500 hold = 0; \
501 bits = 0; \
502 } while (0)
503
504/* Get a byte of input into the bit accumulator, or return from inflate()
505 if there is no input available. */
506#define PULLBYTE() \
507 do { \
508 if (have == 0) goto inf_leave; \
509 have--; \
510 hold += (unsigned long)(*next++) << bits; \
511 bits += 8; \
512 } while (0)
513
514/* Assure that there are at least n bits in the bit accumulator. If there is
515 not enough available input to do that, then return from inflate(). */
516#define NEEDBITS(n) \
517 do { \
518 while (bits < (unsigned)(n)) \
519 PULLBYTE(); \
520 } while (0)
521
522/* Return the low n bits of the bit accumulator (n < 16) */
523#define BITS(n) \
524 ((unsigned)hold & ((1U << (n)) - 1))
525
526/* Remove n bits from the bit accumulator */
527#define DROPBITS(n) \
528 do { \
529 hold >>= (n); \
530 bits -= (unsigned)(n); \
531 } while (0)
532
533/* Remove zero to seven bits as needed to go to a byte boundary */
534#define BYTEBITS() \
535 do { \
536 hold >>= bits & 7; \
537 bits -= bits & 7; \
538 } while (0)
539
87a2b23a 540/*
541 inflate() uses a state machine to process as much input data and generate as
542 much output data as possible before returning. The state machine is
543 structured roughly as follows:
544
545 for (;;) switch (state) {
546 ...
547 case STATEn:
548 if (not enough input data or output space to make progress)
549 return;
550 ... make progress ...
551 state = STATEm;
d8b6dda4 552 break;
87a2b23a 553 ...
554 }
555
556 so when inflate() is called again, the same case is attempted again, and
557 if the appropriate resources are provided, the machine proceeds to the
558 next state. The NEEDBITS() macro is usually the way the state evaluates
559 whether it can proceed or should return. NEEDBITS() does the return if
560 the requested bits are not available. The typical use of the BITS macros
561 is:
562
563 NEEDBITS(n);
564 ... do something with BITS(n) ...
565 DROPBITS(n);
566
567 where NEEDBITS(n) either returns from inflate() if there isn't enough
568 input left to load n bits into the accumulator, or it continues. BITS(n)
569 gives the low n bits in the accumulator. When done, DROPBITS(n) drops
570 the low n bits off the accumulator. INITBITS() clears the accumulator
571 and sets the number of available bits to zero. BYTEBITS() discards just
572 enough bits to put the accumulator on a byte boundary. After BYTEBITS()
573 and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
574
575 NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
576 if there is no input available. The decoding of variable length codes uses
577 PULLBYTE() directly in order to pull just enough bytes to decode the next
578 code, and no more.
579
580 Some states loop until they get enough input, making sure that enough
581 state information is maintained to continue the loop where it left off
582 if NEEDBITS() returns in the loop. For example, want, need, and keep
583 would all have to actually be part of the saved state in case NEEDBITS()
584 returns:
585
586 case STATEw:
587 while (want < need) {
588 NEEDBITS(n);
589 keep[want++] = BITS(n);
590 DROPBITS(n);
591 }
592 state = STATEx;
593 case STATEx:
594
595 As shown above, if the next state is also the next case, then the break
596 is omitted.
597
598 A state may also return if there is not enough output space available to
599 complete that state. Those states are copying stored data, writing a
600 literal byte, and copying a matching string.
601
602 When returning, a "goto inf_leave" is used to update the total counters,
603 update the check value, and determine whether any progress has been made
604 during that inflate() call in order to return the proper return code.
605 Progress is defined as a change in either strm->avail_in or strm->avail_out.
606 When there is a window, goto inf_leave will update the window with the last
607 output written. If a goto inf_leave occurs in the middle of decompression
608 and there is no window currently, goto inf_leave will create one and copy
609 output to the window for the next call of inflate().
610
611 In this implementation, the flush parameter of inflate() only affects the
612 return code (per zlib.h). inflate() always writes as much as possible to
613 strm->next_out, given the space available and the provided input--the effect
614 documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
615 the allocation of and copying into a sliding window until necessary, which
616 provides the effect documented in zlib.h for Z_FINISH when the entire input
617 stream available. So the only thing the flush parameter actually does is:
618 when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
619 will return Z_BUF_ERROR if it has not reached the end of the stream.
620 */
621
622int ZEXPORT inflate(strm, flush)
623z_streamp strm;
624int flush;
625{
626 struct inflate_state FAR *state;
4b57a6ef 627 z_const unsigned char FAR *next; /* next input */
87a2b23a 628 unsigned char FAR *put; /* next output */
629 unsigned have, left; /* available input and output */
630 unsigned long hold; /* bit buffer */
631 unsigned bits; /* bits in bit buffer */
632 unsigned in, out; /* save starting available input and output */
633 unsigned copy; /* number of stored or match bytes to copy */
634 unsigned char FAR *from; /* where to copy match bytes from */
1f54c5b6 635 code here; /* current decoding table entry */
87a2b23a 636 code last; /* parent table entry */
637 unsigned len; /* length to copy for repeats, bits to drop */
638 int ret; /* return code */
639#ifdef GUNZIP
640 unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
641#endif
642 static const unsigned short order[19] = /* permutation of code lengths */
643 {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
644
1e5dce21 645 if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
87a2b23a 646 (strm->next_in == Z_NULL && strm->avail_in != 0))
647 return Z_STREAM_ERROR;
648
649 state = (struct inflate_state FAR *)strm->state;
650 if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
651 LOAD();
652 in = have;
653 out = left;
654 ret = Z_OK;
655 for (;;)
656 switch (state->mode) {
657 case HEAD:
658 if (state->wrap == 0) {
659 state->mode = TYPEDO;
660 break;
661 }
662 NEEDBITS(16);
663#ifdef GUNZIP
664 if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
1e5dce21 665 if (state->wbits == 0)
666 state->wbits = 15;
87a2b23a 667 state->check = crc32(0L, Z_NULL, 0);
668 CRC2(state->check, hold);
669 INITBITS();
670 state->mode = FLAGS;
671 break;
672 }
673 state->flags = 0; /* expect zlib header */
d919a5db 674 if (state->head != Z_NULL)
675 state->head->done = -1;
87a2b23a 676 if (!(state->wrap & 1) || /* check if zlib header allowed */
677#else
678 if (
679#endif
680 ((BITS(8) << 8) + (hold >> 8)) % 31) {
681 strm->msg = (char *)"incorrect header check";
682 state->mode = BAD;
683 break;
684 }
685 if (BITS(4) != Z_DEFLATED) {
686 strm->msg = (char *)"unknown compression method";
687 state->mode = BAD;
688 break;
689 }
690 DROPBITS(4);
d919a5db 691 len = BITS(4) + 8;
1f54c5b6 692 if (state->wbits == 0)
693 state->wbits = len;
1e5dce21 694 if (len > 15 || len > state->wbits) {
87a2b23a 695 strm->msg = (char *)"invalid window size";
696 state->mode = BAD;
697 break;
698 }
d919a5db 699 state->dmax = 1U << len;
87a2b23a 700 Tracev((stderr, "inflate: zlib header ok\n"));
701 strm->adler = state->check = adler32(0L, Z_NULL, 0);
702 state->mode = hold & 0x200 ? DICTID : TYPE;
703 INITBITS();
704 break;
705#ifdef GUNZIP
706 case FLAGS:
707 NEEDBITS(16);
708 state->flags = (int)(hold);
709 if ((state->flags & 0xff) != Z_DEFLATED) {
710 strm->msg = (char *)"unknown compression method";
711 state->mode = BAD;
712 break;
713 }
714 if (state->flags & 0xe000) {
715 strm->msg = (char *)"unknown header flags set";
716 state->mode = BAD;
717 break;
718 }
d919a5db 719 if (state->head != Z_NULL)
720 state->head->text = (int)((hold >> 8) & 1);
1e5dce21 721 if ((state->flags & 0x0200) && (state->wrap & 4))
722 CRC2(state->check, hold);
87a2b23a 723 INITBITS();
724 state->mode = TIME;
725 case TIME:
726 NEEDBITS(32);
d919a5db 727 if (state->head != Z_NULL)
728 state->head->time = hold;
1e5dce21 729 if ((state->flags & 0x0200) && (state->wrap & 4))
730 CRC4(state->check, hold);
87a2b23a 731 INITBITS();
732 state->mode = OS;
733 case OS:
734 NEEDBITS(16);
d919a5db 735 if (state->head != Z_NULL) {
736 state->head->xflags = (int)(hold & 0xff);
737 state->head->os = (int)(hold >> 8);
738 }
1e5dce21 739 if ((state->flags & 0x0200) && (state->wrap & 4))
740 CRC2(state->check, hold);
87a2b23a 741 INITBITS();
742 state->mode = EXLEN;
743 case EXLEN:
744 if (state->flags & 0x0400) {
745 NEEDBITS(16);
746 state->length = (unsigned)(hold);
d919a5db 747 if (state->head != Z_NULL)
748 state->head->extra_len = (unsigned)hold;
1e5dce21 749 if ((state->flags & 0x0200) && (state->wrap & 4))
750 CRC2(state->check, hold);
87a2b23a 751 INITBITS();
752 }
d919a5db 753 else if (state->head != Z_NULL)
754 state->head->extra = Z_NULL;
87a2b23a 755 state->mode = EXTRA;
756 case EXTRA:
757 if (state->flags & 0x0400) {
758 copy = state->length;
759 if (copy > have) copy = have;
760 if (copy) {
d919a5db 761 if (state->head != Z_NULL &&
762 state->head->extra != Z_NULL) {
763 len = state->head->extra_len - state->length;
764 zmemcpy(state->head->extra + len, next,
765 len + copy > state->head->extra_max ?
766 state->head->extra_max - len : copy);
767 }
1e5dce21 768 if ((state->flags & 0x0200) && (state->wrap & 4))
87a2b23a 769 state->check = crc32(state->check, next, copy);
770 have -= copy;
771 next += copy;
772 state->length -= copy;
773 }
774 if (state->length) goto inf_leave;
775 }
d919a5db 776 state->length = 0;
87a2b23a 777 state->mode = NAME;
778 case NAME:
779 if (state->flags & 0x0800) {
780 if (have == 0) goto inf_leave;
781 copy = 0;
782 do {
783 len = (unsigned)(next[copy++]);
d919a5db 784 if (state->head != Z_NULL &&
785 state->head->name != Z_NULL &&
786 state->length < state->head->name_max)
1e5dce21 787 state->head->name[state->length++] = (Bytef)len;
87a2b23a 788 } while (len && copy < have);
1e5dce21 789 if ((state->flags & 0x0200) && (state->wrap & 4))
87a2b23a 790 state->check = crc32(state->check, next, copy);
791 have -= copy;
792 next += copy;
793 if (len) goto inf_leave;
794 }
d919a5db 795 else if (state->head != Z_NULL)
796 state->head->name = Z_NULL;
797 state->length = 0;
87a2b23a 798 state->mode = COMMENT;
799 case COMMENT:
800 if (state->flags & 0x1000) {
801 if (have == 0) goto inf_leave;
802 copy = 0;
803 do {
804 len = (unsigned)(next[copy++]);
d919a5db 805 if (state->head != Z_NULL &&
806 state->head->comment != Z_NULL &&
807 state->length < state->head->comm_max)
1e5dce21 808 state->head->comment[state->length++] = (Bytef)len;
87a2b23a 809 } while (len && copy < have);
1e5dce21 810 if ((state->flags & 0x0200) && (state->wrap & 4))
87a2b23a 811 state->check = crc32(state->check, next, copy);
812 have -= copy;
813 next += copy;
814 if (len) goto inf_leave;
815 }
d919a5db 816 else if (state->head != Z_NULL)
817 state->head->comment = Z_NULL;
87a2b23a 818 state->mode = HCRC;
819 case HCRC:
820 if (state->flags & 0x0200) {
821 NEEDBITS(16);
1e5dce21 822 if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
87a2b23a 823 strm->msg = (char *)"header crc mismatch";
824 state->mode = BAD;
825 break;
826 }
827 INITBITS();
828 }
d919a5db 829 if (state->head != Z_NULL) {
830 state->head->hcrc = (int)((state->flags >> 9) & 1);
831 state->head->done = 1;
832 }
87a2b23a 833 strm->adler = state->check = crc32(0L, Z_NULL, 0);
834 state->mode = TYPE;
835 break;
836#endif
837 case DICTID:
838 NEEDBITS(32);
75e1829f 839 strm->adler = state->check = ZSWAP32(hold);
87a2b23a 840 INITBITS();
841 state->mode = DICT;
842 case DICT:
843 if (state->havedict == 0) {
844 RESTORE();
845 return Z_NEED_DICT;
846 }
847 strm->adler = state->check = adler32(0L, Z_NULL, 0);
848 state->mode = TYPE;
849 case TYPE:
1f54c5b6 850 if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
87a2b23a 851 case TYPEDO:
852 if (state->last) {
853 BYTEBITS();
854 state->mode = CHECK;
855 break;
856 }
857 NEEDBITS(3);
858 state->last = BITS(1);
859 DROPBITS(1);
860 switch (BITS(2)) {
861 case 0: /* stored block */
862 Tracev((stderr, "inflate: stored block%s\n",
863 state->last ? " (last)" : ""));
864 state->mode = STORED;
865 break;
866 case 1: /* fixed block */
867 fixedtables(state);
868 Tracev((stderr, "inflate: fixed codes block%s\n",
869 state->last ? " (last)" : ""));
1f54c5b6 870 state->mode = LEN_; /* decode codes */
871 if (flush == Z_TREES) {
872 DROPBITS(2);
873 goto inf_leave;
874 }
87a2b23a 875 break;
876 case 2: /* dynamic block */
877 Tracev((stderr, "inflate: dynamic codes block%s\n",
878 state->last ? " (last)" : ""));
879 state->mode = TABLE;
880 break;
881 case 3:
882 strm->msg = (char *)"invalid block type";
883 state->mode = BAD;
884 }
885 DROPBITS(2);
886 break;
887 case STORED:
888 BYTEBITS(); /* go to byte boundary */
889 NEEDBITS(32);
890 if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
891 strm->msg = (char *)"invalid stored block lengths";
892 state->mode = BAD;
893 break;
894 }
895 state->length = (unsigned)hold & 0xffff;
896 Tracev((stderr, "inflate: stored length %u\n",
897 state->length));
898 INITBITS();
1f54c5b6 899 state->mode = COPY_;
900 if (flush == Z_TREES) goto inf_leave;
901 case COPY_:
87a2b23a 902 state->mode = COPY;
903 case COPY:
904 copy = state->length;
905 if (copy) {
906 if (copy > have) copy = have;
907 if (copy > left) copy = left;
908 if (copy == 0) goto inf_leave;
909 zmemcpy(put, next, copy);
910 have -= copy;
911 next += copy;
912 left -= copy;
913 put += copy;
914 state->length -= copy;
915 break;
916 }
917 Tracev((stderr, "inflate: stored end\n"));
918 state->mode = TYPE;
919 break;
920 case TABLE:
921 NEEDBITS(14);
922 state->nlen = BITS(5) + 257;
923 DROPBITS(5);
924 state->ndist = BITS(5) + 1;
925 DROPBITS(5);
926 state->ncode = BITS(4) + 4;
927 DROPBITS(4);
928#ifndef PKZIP_BUG_WORKAROUND
929 if (state->nlen > 286 || state->ndist > 30) {
930 strm->msg = (char *)"too many length or distance symbols";
931 state->mode = BAD;
932 break;
933 }
d8b6dda4 934#endif
87a2b23a 935 Tracev((stderr, "inflate: table sizes ok\n"));
936 state->have = 0;
937 state->mode = LENLENS;
938 case LENLENS:
939 while (state->have < state->ncode) {
940 NEEDBITS(3);
941 state->lens[order[state->have++]] = (unsigned short)BITS(3);
942 DROPBITS(3);
943 }
944 while (state->have < 19)
945 state->lens[order[state->have++]] = 0;
946 state->next = state->codes;
4b57a6ef 947 state->lencode = (const code FAR *)(state->next);
87a2b23a 948 state->lenbits = 7;
949 ret = inflate_table(CODES, state->lens, 19, &(state->next),
950 &(state->lenbits), state->work);
951 if (ret) {
952 strm->msg = (char *)"invalid code lengths set";
953 state->mode = BAD;
954 break;
955 }
956 Tracev((stderr, "inflate: code lengths ok\n"));
957 state->have = 0;
958 state->mode = CODELENS;
959 case CODELENS:
960 while (state->have < state->nlen + state->ndist) {
961 for (;;) {
1f54c5b6 962 here = state->lencode[BITS(state->lenbits)];
963 if ((unsigned)(here.bits) <= bits) break;
87a2b23a 964 PULLBYTE();
965 }
1f54c5b6 966 if (here.val < 16) {
1f54c5b6 967 DROPBITS(here.bits);
968 state->lens[state->have++] = here.val;
87a2b23a 969 }
970 else {
1f54c5b6 971 if (here.val == 16) {
972 NEEDBITS(here.bits + 2);
973 DROPBITS(here.bits);
87a2b23a 974 if (state->have == 0) {
975 strm->msg = (char *)"invalid bit length repeat";
976 state->mode = BAD;
977 break;
978 }
979 len = state->lens[state->have - 1];
980 copy = 3 + BITS(2);
981 DROPBITS(2);
982 }
1f54c5b6 983 else if (here.val == 17) {
984 NEEDBITS(here.bits + 3);
985 DROPBITS(here.bits);
87a2b23a 986 len = 0;
987 copy = 3 + BITS(3);
988 DROPBITS(3);
989 }
990 else {
1f54c5b6 991 NEEDBITS(here.bits + 7);
992 DROPBITS(here.bits);
87a2b23a 993 len = 0;
994 copy = 11 + BITS(7);
995 DROPBITS(7);
996 }
997 if (state->have + copy > state->nlen + state->ndist) {
998 strm->msg = (char *)"invalid bit length repeat";
999 state->mode = BAD;
1000 break;
1001 }
1002 while (copy--)
1003 state->lens[state->have++] = (unsigned short)len;
1004 }
1005 }
1006
d919a5db 1007 /* handle error breaks in while */
1008 if (state->mode == BAD) break;
1009
1f54c5b6 1010 /* check for end-of-block code (better have one) */
1011 if (state->lens[256] == 0) {
1012 strm->msg = (char *)"invalid code -- missing end-of-block";
1013 state->mode = BAD;
1014 break;
1015 }
1016
1017 /* build code tables -- note: do not change the lenbits or distbits
1018 values here (9 and 6) without reading the comments in inftrees.h
1019 concerning the ENOUGH constants, which depend on those values */
87a2b23a 1020 state->next = state->codes;
4b57a6ef 1021 state->lencode = (const code FAR *)(state->next);
87a2b23a 1022 state->lenbits = 9;
1023 ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1024 &(state->lenbits), state->work);
1025 if (ret) {
1026 strm->msg = (char *)"invalid literal/lengths set";
1027 state->mode = BAD;
1028 break;
1029 }
4b57a6ef 1030 state->distcode = (const code FAR *)(state->next);
87a2b23a 1031 state->distbits = 6;
1032 ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1033 &(state->next), &(state->distbits), state->work);
1034 if (ret) {
1035 strm->msg = (char *)"invalid distances set";
1036 state->mode = BAD;
1037 break;
1038 }
1039 Tracev((stderr, "inflate: codes ok\n"));
1f54c5b6 1040 state->mode = LEN_;
1041 if (flush == Z_TREES) goto inf_leave;
1042 case LEN_:
87a2b23a 1043 state->mode = LEN;
1044 case LEN:
1045 if (have >= 6 && left >= 258) {
1046 RESTORE();
1047 inflate_fast(strm, out);
1048 LOAD();
1f54c5b6 1049 if (state->mode == TYPE)
1050 state->back = -1;
87a2b23a 1051 break;
1052 }
1f54c5b6 1053 state->back = 0;
87a2b23a 1054 for (;;) {
1f54c5b6 1055 here = state->lencode[BITS(state->lenbits)];
1056 if ((unsigned)(here.bits) <= bits) break;
87a2b23a 1057 PULLBYTE();
1058 }
1f54c5b6 1059 if (here.op && (here.op & 0xf0) == 0) {
1060 last = here;
87a2b23a 1061 for (;;) {
1f54c5b6 1062 here = state->lencode[last.val +
87a2b23a 1063 (BITS(last.bits + last.op) >> last.bits)];
1f54c5b6 1064 if ((unsigned)(last.bits + here.bits) <= bits) break;
87a2b23a 1065 PULLBYTE();
1066 }
1067 DROPBITS(last.bits);
1f54c5b6 1068 state->back += last.bits;
87a2b23a 1069 }
1f54c5b6 1070 DROPBITS(here.bits);
1071 state->back += here.bits;
1072 state->length = (unsigned)here.val;
1073 if ((int)(here.op) == 0) {
1074 Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
87a2b23a 1075 "inflate: literal '%c'\n" :
1f54c5b6 1076 "inflate: literal 0x%02x\n", here.val));
87a2b23a 1077 state->mode = LIT;
1078 break;
1079 }
1f54c5b6 1080 if (here.op & 32) {
87a2b23a 1081 Tracevv((stderr, "inflate: end of block\n"));
1f54c5b6 1082 state->back = -1;
87a2b23a 1083 state->mode = TYPE;
1084 break;
1085 }
1f54c5b6 1086 if (here.op & 64) {
87a2b23a 1087 strm->msg = (char *)"invalid literal/length code";
1088 state->mode = BAD;
1089 break;
1090 }
1f54c5b6 1091 state->extra = (unsigned)(here.op) & 15;
87a2b23a 1092 state->mode = LENEXT;
1093 case LENEXT:
1094 if (state->extra) {
1095 NEEDBITS(state->extra);
1096 state->length += BITS(state->extra);
1097 DROPBITS(state->extra);
1f54c5b6 1098 state->back += state->extra;
87a2b23a 1099 }
1100 Tracevv((stderr, "inflate: length %u\n", state->length));
1f54c5b6 1101 state->was = state->length;
87a2b23a 1102 state->mode = DIST;
1103 case DIST:
1104 for (;;) {
1f54c5b6 1105 here = state->distcode[BITS(state->distbits)];
1106 if ((unsigned)(here.bits) <= bits) break;
87a2b23a 1107 PULLBYTE();
1108 }
1f54c5b6 1109 if ((here.op & 0xf0) == 0) {
1110 last = here;
87a2b23a 1111 for (;;) {
1f54c5b6 1112 here = state->distcode[last.val +
87a2b23a 1113 (BITS(last.bits + last.op) >> last.bits)];
1f54c5b6 1114 if ((unsigned)(last.bits + here.bits) <= bits) break;
87a2b23a 1115 PULLBYTE();
1116 }
1117 DROPBITS(last.bits);
1f54c5b6 1118 state->back += last.bits;
87a2b23a 1119 }
1f54c5b6 1120 DROPBITS(here.bits);
1121 state->back += here.bits;
1122 if (here.op & 64) {
87a2b23a 1123 strm->msg = (char *)"invalid distance code";
1124 state->mode = BAD;
1125 break;
1126 }
1f54c5b6 1127 state->offset = (unsigned)here.val;
1128 state->extra = (unsigned)(here.op) & 15;
87a2b23a 1129 state->mode = DISTEXT;
1130 case DISTEXT:
1131 if (state->extra) {
1132 NEEDBITS(state->extra);
1133 state->offset += BITS(state->extra);
1134 DROPBITS(state->extra);
1f54c5b6 1135 state->back += state->extra;
87a2b23a 1136 }
d919a5db 1137#ifdef INFLATE_STRICT
1138 if (state->offset > state->dmax) {
1139 strm->msg = (char *)"invalid distance too far back";
1140 state->mode = BAD;
1141 break;
1142 }
1143#endif
87a2b23a 1144 Tracevv((stderr, "inflate: distance %u\n", state->offset));
1145 state->mode = MATCH;
1146 case MATCH:
1147 if (left == 0) goto inf_leave;
1148 copy = out - left;
1149 if (state->offset > copy) { /* copy from window */
1150 copy = state->offset - copy;
1f54c5b6 1151 if (copy > state->whave) {
1152 if (state->sane) {
1153 strm->msg = (char *)"invalid distance too far back";
1154 state->mode = BAD;
1155 break;
1156 }
1157#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1158 Trace((stderr, "inflate.c too far\n"));
1159 copy -= state->whave;
1160 if (copy > state->length) copy = state->length;
1161 if (copy > left) copy = left;
1162 left -= copy;
1163 state->length -= copy;
1164 do {
1165 *put++ = 0;
1166 } while (--copy);
1167 if (state->length == 0) state->mode = LEN;
1168 break;
1169#endif
1170 }
1171 if (copy > state->wnext) {
1172 copy -= state->wnext;
87a2b23a 1173 from = state->window + (state->wsize - copy);
1174 }
1175 else
1f54c5b6 1176 from = state->window + (state->wnext - copy);
87a2b23a 1177 if (copy > state->length) copy = state->length;
1178 }
1179 else { /* copy from output */
1180 from = put - state->offset;
1181 copy = state->length;
1182 }
1183 if (copy > left) copy = left;
1184 left -= copy;
1185 state->length -= copy;
1186 do {
1187 *put++ = *from++;
1188 } while (--copy);
1189 if (state->length == 0) state->mode = LEN;
1190 break;
1191 case LIT:
1192 if (left == 0) goto inf_leave;
1193 *put++ = (unsigned char)(state->length);
1194 left--;
1195 state->mode = LEN;
1196 break;
1197 case CHECK:
1198 if (state->wrap) {
1199 NEEDBITS(32);
1200 out -= left;
1201 strm->total_out += out;
1202 state->total += out;
1e5dce21 1203 if ((state->wrap & 4) && out)
87a2b23a 1204 strm->adler = state->check =
1205 UPDATE(state->check, put - out, out);
1206 out = left;
1e5dce21 1207 if ((state->wrap & 4) && (
87a2b23a 1208#ifdef GUNZIP
1209 state->flags ? hold :
1210#endif
75e1829f 1211 ZSWAP32(hold)) != state->check) {
87a2b23a 1212 strm->msg = (char *)"incorrect data check";
1213 state->mode = BAD;
1214 break;
1215 }
1216 INITBITS();
1217 Tracev((stderr, "inflate: check matches trailer\n"));
1218 }
1219#ifdef GUNZIP
1220 state->mode = LENGTH;
1221 case LENGTH:
1222 if (state->wrap && state->flags) {
1223 NEEDBITS(32);
1224 if (hold != (state->total & 0xffffffffUL)) {
1225 strm->msg = (char *)"incorrect length check";
1226 state->mode = BAD;
1227 break;
1228 }
1229 INITBITS();
1230 Tracev((stderr, "inflate: length matches trailer\n"));
1231 }
1232#endif
1233 state->mode = DONE;
1234 case DONE:
1235 ret = Z_STREAM_END;
1236 goto inf_leave;
1237 case BAD:
1238 ret = Z_DATA_ERROR;
1239 goto inf_leave;
1240 case MEM:
1241 return Z_MEM_ERROR;
1242 case SYNC:
1243 default:
1244 return Z_STREAM_ERROR;
1245 }
1246
1247 /*
1248 Return from inflate(), updating the total counts and the check value.
1249 If there was no progress during the inflate() call, return a buffer
1250 error. Call updatewindow() to create and/or update the window state.
1251 Note: a memory error from inflate() is non-recoverable.
1252 */
1253 inf_leave:
1254 RESTORE();
75e1829f 1255 if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
1256 (state->mode < CHECK || flush != Z_FINISH)))
4b57a6ef 1257 if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
87a2b23a 1258 state->mode = MEM;
1259 return Z_MEM_ERROR;
1260 }
1261 in -= strm->avail_in;
1262 out -= strm->avail_out;
1263 strm->total_in += in;
1264 strm->total_out += out;
1265 state->total += out;
1e5dce21 1266 if ((state->wrap & 4) && out)
87a2b23a 1267 strm->adler = state->check =
1268 UPDATE(state->check, strm->next_out - out, out);
1e5dce21 1269 strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
1f54c5b6 1270 (state->mode == TYPE ? 128 : 0) +
1271 (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
87a2b23a 1272 if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1273 ret = Z_BUF_ERROR;
1274 return ret;
d8b6dda4 1275}
1276
87a2b23a 1277int ZEXPORT inflateEnd(strm)
1278z_streamp strm;
1279{
1280 struct inflate_state FAR *state;
1e5dce21 1281 if (inflateStateCheck(strm))
87a2b23a 1282 return Z_STREAM_ERROR;
1283 state = (struct inflate_state FAR *)strm->state;
1284 if (state->window != Z_NULL) ZFREE(strm, state->window);
1285 ZFREE(strm, strm->state);
1286 strm->state = Z_NULL;
1287 Tracev((stderr, "inflate: end\n"));
1288 return Z_OK;
1289}
d8b6dda4 1290
4b57a6ef 1291int ZEXPORT inflateGetDictionary(strm, dictionary, dictLength)
1292z_streamp strm;
1293Bytef *dictionary;
1294uInt *dictLength;
1295{
1296 struct inflate_state FAR *state;
1297
1298 /* check state */
1e5dce21 1299 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
4b57a6ef 1300 state = (struct inflate_state FAR *)strm->state;
1301
1302 /* copy dictionary */
1303 if (state->whave && dictionary != Z_NULL) {
1304 zmemcpy(dictionary, state->window + state->wnext,
1305 state->whave - state->wnext);
1306 zmemcpy(dictionary + state->whave - state->wnext,
1307 state->window, state->wnext);
1308 }
1309 if (dictLength != Z_NULL)
1310 *dictLength = state->whave;
1311 return Z_OK;
1312}
1313
87a2b23a 1314int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
1315z_streamp strm;
d8b6dda4 1316const Bytef *dictionary;
87a2b23a 1317uInt dictLength;
d8b6dda4 1318{
87a2b23a 1319 struct inflate_state FAR *state;
75e1829f 1320 unsigned long dictid;
75e1829f 1321 int ret;
d8b6dda4 1322
87a2b23a 1323 /* check state */
1e5dce21 1324 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
87a2b23a 1325 state = (struct inflate_state FAR *)strm->state;
d919a5db 1326 if (state->wrap != 0 && state->mode != DICT)
1327 return Z_STREAM_ERROR;
d8b6dda4 1328
75e1829f 1329 /* check for correct dictionary identifier */
d919a5db 1330 if (state->mode == DICT) {
75e1829f 1331 dictid = adler32(0L, Z_NULL, 0);
1332 dictid = adler32(dictid, dictionary, dictLength);
1333 if (dictid != state->check)
d919a5db 1334 return Z_DATA_ERROR;
1335 }
87a2b23a 1336
75e1829f 1337 /* copy dictionary to window using updatewindow(), which will amend the
1338 existing dictionary if appropriate */
4b57a6ef 1339 ret = updatewindow(strm, dictionary + dictLength, dictLength);
75e1829f 1340 if (ret) {
87a2b23a 1341 state->mode = MEM;
1342 return Z_MEM_ERROR;
1343 }
87a2b23a 1344 state->havedict = 1;
1345 Tracev((stderr, "inflate: dictionary set\n"));
1346 return Z_OK;
1347}
1348
d919a5db 1349int ZEXPORT inflateGetHeader(strm, head)
1350z_streamp strm;
1351gz_headerp head;
1352{
1353 struct inflate_state FAR *state;
1354
1355 /* check state */
1e5dce21 1356 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
d919a5db 1357 state = (struct inflate_state FAR *)strm->state;
1358 if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
1359
1360 /* save header structure */
1361 state->head = head;
1362 head->done = 0;
1363 return Z_OK;
1364}
1365
87a2b23a 1366/*
1367 Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found
1368 or when out of input. When called, *have is the number of pattern bytes
1369 found in order so far, in 0..3. On return *have is updated to the new
1370 state. If on return *have equals four, then the pattern was found and the
1371 return value is how many bytes were read including the last byte of the
1372 pattern. If *have is less than four, then the pattern has not been found
1373 yet and the return value is len. In the latter case, syncsearch() can be
1374 called again with more data and the *have state. *have is initialized to
1375 zero for the first call.
1376 */
1377local unsigned syncsearch(have, buf, len)
1378unsigned FAR *have;
4b57a6ef 1379const unsigned char FAR *buf;
87a2b23a 1380unsigned len;
d8b6dda4 1381{
87a2b23a 1382 unsigned got;
1383 unsigned next;
1384
1385 got = *have;
1386 next = 0;
1387 while (next < len && got < 4) {
1388 if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
1389 got++;
1390 else if (buf[next])
1391 got = 0;
1392 else
1393 got = 4 - got;
1394 next++;
1395 }
1396 *have = got;
1397 return next;
d8b6dda4 1398}
1399
87a2b23a 1400int ZEXPORT inflateSync(strm)
1401z_streamp strm;
1402{
1403 unsigned len; /* number of bytes to look at or looked at */
1404 unsigned long in, out; /* temporary to save total_in and total_out */
1405 unsigned char buf[4]; /* to restore bit buffer to byte string */
1406 struct inflate_state FAR *state;
d8b6dda4 1407
87a2b23a 1408 /* check parameters */
1e5dce21 1409 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
87a2b23a 1410 state = (struct inflate_state FAR *)strm->state;
1411 if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
1412
1413 /* if first time, start search in bit buffer */
1414 if (state->mode != SYNC) {
1415 state->mode = SYNC;
1416 state->hold <<= state->bits & 7;
1417 state->bits -= state->bits & 7;
1418 len = 0;
1419 while (state->bits >= 8) {
1420 buf[len++] = (unsigned char)(state->hold);
1421 state->hold >>= 8;
1422 state->bits -= 8;
1423 }
1424 state->have = 0;
1425 syncsearch(&(state->have), buf, len);
1426 }
1427
1428 /* search available input */
1429 len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
1430 strm->avail_in -= len;
1431 strm->next_in += len;
1432 strm->total_in += len;
1433
1434 /* return no joy or set up to restart inflate() on a new block */
1435 if (state->have != 4) return Z_DATA_ERROR;
1436 in = strm->total_in; out = strm->total_out;
1437 inflateReset(strm);
1438 strm->total_in = in; strm->total_out = out;
1439 state->mode = TYPE;
1440 return Z_OK;
1441}
1442
1443/*
1444 Returns true if inflate is currently at the end of a block generated by
1445 Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
1446 implementation to provide an additional safety check. PPP uses
1447 Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
1448 block. When decompressing, PPP checks that at the end of input packet,
1449 inflate is waiting for these length bytes.
d8b6dda4 1450 */
87a2b23a 1451int ZEXPORT inflateSyncPoint(strm)
1452z_streamp strm;
1453{
1454 struct inflate_state FAR *state;
1455
1e5dce21 1456 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
87a2b23a 1457 state = (struct inflate_state FAR *)strm->state;
1458 return state->mode == STORED && state->bits == 0;
1459}
1460
1461int ZEXPORT inflateCopy(dest, source)
1462z_streamp dest;
1463z_streamp source;
d8b6dda4 1464{
87a2b23a 1465 struct inflate_state FAR *state;
1466 struct inflate_state FAR *copy;
1467 unsigned char FAR *window;
d919a5db 1468 unsigned wsize;
87a2b23a 1469
1470 /* check input */
1e5dce21 1471 if (inflateStateCheck(source) || dest == Z_NULL)
87a2b23a 1472 return Z_STREAM_ERROR;
1473 state = (struct inflate_state FAR *)source->state;
1474
1475 /* allocate space */
1476 copy = (struct inflate_state FAR *)
1477 ZALLOC(source, 1, sizeof(struct inflate_state));
1478 if (copy == Z_NULL) return Z_MEM_ERROR;
1479 window = Z_NULL;
1480 if (state->window != Z_NULL) {
1481 window = (unsigned char FAR *)
1482 ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
1483 if (window == Z_NULL) {
1484 ZFREE(source, copy);
1485 return Z_MEM_ERROR;
1486 }
1487 }
1488
1489 /* copy state */
75e1829f 1490 zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
1491 zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state));
1e5dce21 1492 copy->strm = dest;
d919a5db 1493 if (state->lencode >= state->codes &&
1494 state->lencode <= state->codes + ENOUGH - 1) {
1495 copy->lencode = copy->codes + (state->lencode - state->codes);
1496 copy->distcode = copy->codes + (state->distcode - state->codes);
1497 }
87a2b23a 1498 copy->next = copy->codes + (state->next - state->codes);
d919a5db 1499 if (window != Z_NULL) {
1500 wsize = 1U << state->wbits;
1501 zmemcpy(window, state->window, wsize);
1502 }
87a2b23a 1503 copy->window = window;
d919a5db 1504 dest->state = (struct internal_state FAR *)copy;
87a2b23a 1505 return Z_OK;
d8b6dda4 1506}
1f54c5b6 1507
1508int ZEXPORT inflateUndermine(strm, subvert)
1509z_streamp strm;
1510int subvert;
1511{
1512 struct inflate_state FAR *state;
1513
1e5dce21 1514 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1f54c5b6 1515 state = (struct inflate_state FAR *)strm->state;
1f54c5b6 1516#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1e5dce21 1517 state->sane = !subvert;
1f54c5b6 1518 return Z_OK;
1519#else
1e5dce21 1520 (void)subvert;
1f54c5b6 1521 state->sane = 1;
1522 return Z_DATA_ERROR;
1523#endif
1524}
1525
1e5dce21 1526int ZEXPORT inflateValidate(strm, check)
1527z_streamp strm;
1528int check;
1529{
1530 struct inflate_state FAR *state;
1531
1532 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1533 state = (struct inflate_state FAR *)strm->state;
1534 if (check)
1535 state->wrap |= 4;
1536 else
1537 state->wrap &= ~4;
1538 return Z_OK;
1539}
1540
1f54c5b6 1541long ZEXPORT inflateMark(strm)
1542z_streamp strm;
1543{
1544 struct inflate_state FAR *state;
1545
1e5dce21 1546 if (inflateStateCheck(strm))
1547 return -(1L << 16);
1f54c5b6 1548 state = (struct inflate_state FAR *)strm->state;
1e5dce21 1549 return (long)(((unsigned long)((long)state->back)) << 16) +
1f54c5b6 1550 (state->mode == COPY ? state->length :
1551 (state->mode == MATCH ? state->was - state->length : 0));
1552}
1e5dce21 1553
1554unsigned long ZEXPORT inflateCodesUsed(strm)
1555z_streamp strm;
1556{
1557 struct inflate_state FAR *state;
1558 if (inflateStateCheck(strm)) return (unsigned long)-1;
1559 state = (struct inflate_state FAR *)strm->state;
1560 return (unsigned long)(state->next - state->codes);
1561}