1/* inflate.c -- zlib decompression
2 * Copyright (C) 1995-2016 Mark Adler
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
5
6/*
7 * Change history:
8 *
9 * 1.2.beta0 24 Nov 2002
10 * - First version -- complete rewrite of inflate to simplify code, avoid
11 * creation of window when not needed, minimize use of window when it is
12 * needed, make inffast.c even faster, implement gzip decoding, and to
13 * improve code readability and style over the previous zlib inflate code
14 *
15 * 1.2.beta1 25 Nov 2002
16 * - Use pointers for available input and output checking in inffast.c
17 * - Remove input and output counters in inffast.c
18 * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
19 * - Remove unnecessary second byte pull from length extra in inffast.c
20 * - Unroll direct copy to three copies per loop in inffast.c
21 *
22 * 1.2.beta2 4 Dec 2002
23 * - Change external routine names to reduce potential conflicts
24 * - Correct filename to inffixed.h for fixed tables in inflate.c
25 * - Make hbuf[] unsigned char to match parameter type in inflate.c
26 * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
27 * to avoid negation problem on Alphas (64 bit) in inflate.c
28 *
29 * 1.2.beta3 22 Dec 2002
30 * - Add comments on state->bits assertion in inffast.c
31 * - Add comments on op field in inftrees.h
32 * - Fix bug in reuse of allocated window after inflateReset()
33 * - Remove bit fields--back to byte structure for speed
34 * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
35 * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
36 * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
37 * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
38 * - Use local copies of stream next and avail values, as well as local bit
39 * buffer and bit count in inflate()--for speed when inflate_fast() not used
40 *
41 * 1.2.beta4 1 Jan 2003
42 * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
43 * - Move a comment on output buffer sizes from inffast.c to inflate.c
44 * - Add comments in inffast.c to introduce the inflate_fast() routine
45 * - Rearrange window copies in inflate_fast() for speed and simplification
46 * - Unroll last copy for window match in inflate_fast()
47 * - Use local copies of window variables in inflate_fast() for speed
48 * - Pull out common wnext == 0 case for speed in inflate_fast()
49 * - Make op and len in inflate_fast() unsigned for consistency
50 * - Add FAR to lcode and dcode declarations in inflate_fast()
51 * - Simplified bad distance check in inflate_fast()
52 * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
53 * source file infback.c to provide a call-back interface to inflate for
54 * programs like gzip and unzip -- uses window as output buffer to avoid
55 * window copying
56 *
57 * 1.2.beta5 1 Jan 2003
58 * - Improved inflateBack() interface to allow the caller to provide initial
59 * input in strm.
60 * - Fixed stored blocks bug in inflateBack()
61 *
62 * 1.2.beta6 4 Jan 2003
63 * - Added comments in inffast.c on effectiveness of POSTINC
64 * - Typecasting all around to reduce compiler warnings
65 * - Changed loops from while (1) or do {} while (1) to for (;;), again to
66 * make compilers happy
67 * - Changed type of window in inflateBackInit() to unsigned char *
68 *
69 * 1.2.beta7 27 Jan 2003
70 * - Changed many types to unsigned or unsigned short to avoid warnings
71 * - Added inflateCopy() function
72 *
73 * 1.2.0 9 Mar 2003
74 * - Changed inflateBack() interface to provide separate opaque descriptors
75 * for the in() and out() functions
76 * - Changed inflateBack() argument and in_func typedef to swap the length
77 * and buffer address return values for the input function
78 * - Check next_in and next_out for Z_NULL on entry to inflate()
79 *
80 * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
81 */
82
83#include "zutil.h"
84#include "inftrees.h"
85#include "inflate.h"
86#include "inffast.h"
87
88#ifdef MAKEFIXED
89# ifndef BUILDFIXED
90# define BUILDFIXED
91# endif
92#endif
93
94/* function prototypes */
95local int inflateStateCheck OF((z_streamp strm));
96local void fixedtables OF((struct inflate_state FAR *state));
97local int updatewindow OF((z_streamp strm, const unsigned char FAR *end,
98 unsigned copy));
99#ifdef BUILDFIXED
100 void makefixed OF((void));
101#endif
102local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf,
103 unsigned len));
104
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
119int ZEXPORT inflateResetKeep(strm)
120z_streamp strm;
121{
122 struct inflate_state FAR *state;
123
124 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
125 state = (struct inflate_state FAR *)strm->state;
126 strm->total_in = strm->total_out = state->total = 0;
127 strm->msg = Z_NULL;
128 if (state->wrap) /* to support ill-conceived Java test suite */
129 strm->adler = state->wrap & 1;
130 state->mode = HEAD;
131 state->last = 0;
132 state->havedict = 0;
133 state->dmax = 32768U;
134 state->head = Z_NULL;
135 state->hold = 0;
136 state->bits = 0;
137 state->lencode = state->distcode = state->next = state->codes;
138 state->sane = 1;
139 state->back = -1;
140 Tracev((stderr, "inflate: reset\n"));
141 return Z_OK;
142}
143
144int ZEXPORT inflateReset(strm)
145z_streamp strm;
146{
147 struct inflate_state FAR *state;
148
149 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
150 state = (struct inflate_state FAR *)strm->state;
151 state->wsize = 0;
152 state->whave = 0;
153 state->wnext = 0;
154 return inflateResetKeep(strm);
155}
156
157int ZEXPORT inflateReset2(strm, windowBits)
158z_streamp strm;
159int windowBits;
160{
161 int wrap;
162 struct inflate_state FAR *state;
163
164 /* get the state */
165 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
166 state = (struct inflate_state FAR *)strm->state;
167
168 /* extract wrap request from windowBits parameter */
169 if (windowBits < 0) {
170 wrap = 0;
171 windowBits = -windowBits;
172 }
173 else {
174 wrap = (windowBits >> 4) + 5;
175#ifdef GUNZIP
176 if (windowBits < 48)
177 windowBits &= 15;
178#endif
179 }
180
181 /* set number of window bits, free window if different */
182 if (windowBits && (windowBits < 8 || windowBits > 15))
183 return Z_STREAM_ERROR;
184 if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
185 ZFREE(strm, state->window);
186 state->window = Z_NULL;
187 }
188
189 /* update state and reset the rest of it */
190 state->wrap = wrap;
191 state->wbits = (unsigned)windowBits;
192 return inflateReset(strm);
193}
194
195int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
196z_streamp strm;
197int windowBits;
198const char *version;
199int stream_size;
200{
201 int ret;
202 struct inflate_state FAR *state;
203
204 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
205 stream_size != (int)(sizeof(z_stream)))
206 return Z_VERSION_ERROR;
207 if (strm == Z_NULL) return Z_STREAM_ERROR;
208 strm->msg = Z_NULL; /* in case we return an error */
209 if (strm->zalloc == (alloc_func)0) {
210#ifdef Z_SOLO
211 return Z_STREAM_ERROR;
212#else
213 strm->zalloc = zcalloc;
214 strm->opaque = (voidpf)0;
215#endif
216 }
217 if (strm->zfree == (free_func)0)
218#ifdef Z_SOLO
219 return Z_STREAM_ERROR;
220#else
221 strm->zfree = zcfree;
222#endif
223 state = (struct inflate_state FAR *)
224 ZALLOC(strm, 1, sizeof(struct inflate_state));
225 if (state == Z_NULL) return Z_MEM_ERROR;
226 Tracev((stderr, "inflate: allocated\n"));
227 strm->state = (struct internal_state FAR *)state;
228 state->strm = strm;
229 state->window = Z_NULL;
230 state->mode = HEAD; /* to pass state test in inflateReset2() */
231 state->check = 1L; /* 1L is the result of adler32() zero length data */
232 ret = inflateReset2(strm, windowBits);
233 if (ret != Z_OK) {
234 ZFREE(strm, state);
235 strm->state = Z_NULL;
236 }
237 return ret;
238}
239
240int ZEXPORT inflateInit_(strm, version, stream_size)
241z_streamp strm;
242const char *version;
243int stream_size;
244{
245 return inflateInit2_(strm, DEF_WBITS, version, stream_size);
246}
247
248int ZEXPORT inflatePrime(strm, bits, value)
249z_streamp strm;
250int bits;
251int value;
252{
253 struct inflate_state FAR *state;
254
255 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
256 state = (struct inflate_state FAR *)strm->state;
257 if (bits < 0) {
258 state->hold = 0;
259 state->bits = 0;
260 return Z_OK;
261 }
262 if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR;
263 value &= (1L << bits) - 1;
264 state->hold += (unsigned)value << state->bits;
265 state->bits += (uInt)bits;
266 return Z_OK;
267}
268
269/*
270 Return state with length and distance decoding tables and index sizes set to
271 fixed code decoding. Normally this returns fixed tables from inffixed.h.
272 If BUILDFIXED is defined, then instead this routine builds the tables the
273 first time it's called, and returns those tables the first time and
274 thereafter. This reduces the size of the code by about 2K bytes, in
275 exchange for a little execution time. However, BUILDFIXED should not be
276 used for threaded applications, since the rewriting of the tables and virgin
277 may not be thread-safe.
278 */
279local void fixedtables(state)
280struct inflate_state FAR *state;
281{
282#ifdef BUILDFIXED
283 static int virgin = 1;
284 static code *lenfix, *distfix;
285 static code fixed[544];
286
287 /* build fixed huffman tables if first call (may not be thread safe) */
288 if (virgin) {
289 unsigned sym, bits;
290 static code *next;
291
292 /* literal/length table */
293 sym = 0;
294 while (sym < 144) state->lens[sym++] = 8;
295 while (sym < 256) state->lens[sym++] = 9;
296 while (sym < 280) state->lens[sym++] = 7;
297 while (sym < 288) state->lens[sym++] = 8;
298 next = fixed;
299 lenfix = next;
300 bits = 9;
301 inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
302
303 /* distance table */
304 sym = 0;
305 while (sym < 32) state->lens[sym++] = 5;
306 distfix = next;
307 bits = 5;
308 inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
309
310 /* do this just once */
311 virgin = 0;
312 }
313#else /* !BUILDFIXED */
314# include "inffixed.h"
315#endif /* BUILDFIXED */
316 state->lencode = lenfix;
317 state->lenbits = 9;
318 state->distcode = distfix;
319 state->distbits = 5;
320}
321
322#ifdef MAKEFIXED
323#include <stdio.h>
324
325/*
326 Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also
327 defines BUILDFIXED, so the tables are built on the fly. makefixed() writes
328 those tables to stdout, which would be piped to inffixed.h. A small program
329 can simply call makefixed to do this:
330
331 void makefixed(void);
332
333 int main(void)
334 {
335 makefixed();
336 return 0;
337 }
338
339 Then that can be linked with zlib built with MAKEFIXED defined and run:
340
341 a.out > inffixed.h
342 */
343void makefixed()
344{
345 unsigned low, size;
346 struct inflate_state state;
347
348 fixedtables(&state);
349 puts(" /* inffixed.h -- table for decoding fixed codes");
350 puts(" * Generated automatically by makefixed().");
351 puts(" */");
352 puts("");
353 puts(" /* WARNING: this file should *not* be used by applications.");
354 puts(" It is part of the implementation of this library and is");
355 puts(" subject to change. Applications should only use zlib.h.");
356 puts(" */");
357 puts("");
358 size = 1U << 9;
359 printf(" static const code lenfix[%u] = {", size);
360 low = 0;
361 for (;;) {
362 if ((low % 7) == 0) printf("\n ");
363 printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op,
364 state.lencode[low].bits, state.lencode[low].val);
365 if (++low == size) break;
366 putchar(',');
367 }
368 puts("\n };");
369 size = 1U << 5;
370 printf("\n static const code distfix[%u] = {", size);
371 low = 0;
372 for (;;) {
373 if ((low % 6) == 0) printf("\n ");
374 printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
375 state.distcode[low].val);
376 if (++low == size) break;
377 putchar(',');
378 }
379 puts("\n };");
380}
381#endif /* MAKEFIXED */
382
383/*
384 Update the window with the last wsize (normally 32K) bytes written before
385 returning. If window does not exist yet, create it. This is only called
386 when a window is already in use, or when output has been written during this
387 inflate call, but the end of the deflate stream has not been reached yet.
388 It is also called to create a window for dictionary data when a dictionary
389 is loaded.
390
391 Providing output buffers larger than 32K to inflate() should provide a speed
392 advantage, since only the last 32K of output is copied to the sliding window
393 upon return from inflate(), and since all distances after the first 32K of
394 output will fall in the output data, making match copies simpler and faster.
395 The advantage may be dependent on the size of the processor's data caches.
396 */
397local int updatewindow(strm, end, copy)
398z_streamp strm;
399const Bytef *end;
400unsigned copy;
401{
402 struct inflate_state FAR *state;
403 unsigned dist;
404
405 state = (struct inflate_state FAR *)strm->state;
406
407 /* if it hasn't been done already, allocate space for the window */
408 if (state->window == Z_NULL) {
409 state->window = (unsigned char FAR *)
410 ZALLOC(strm, 1U << state->wbits,
411 sizeof(unsigned char));
412 if (state->window == Z_NULL) return 1;
413 }
414
415 /* if window not in use yet, initialize */
416 if (state->wsize == 0) {
417 state->wsize = 1U << state->wbits;
418 state->wnext = 0;
419 state->whave = 0;
420 }
421
422 /* copy state->wsize or less output bytes into the circular window */
423 if (copy >= state->wsize) {
424 zmemcpy(state->window, end - state->wsize, state->wsize);
425 state->wnext = 0;
426 state->whave = state->wsize;
427 }
428 else {
429 dist = state->wsize - state->wnext;
430 if (dist > copy) dist = copy;
431 zmemcpy(state->window + state->wnext, end - copy, dist);
432 copy -= dist;
433 if (copy) {
434 zmemcpy(state->window, end - copy, copy);
435 state->wnext = copy;
436 state->whave = state->wsize;
437 }
438 else {
439 state->wnext += dist;
440 if (state->wnext == state->wsize) state->wnext = 0;
441 if (state->whave < state->wsize) state->whave += dist;
442 }
443 }
444 return 0;
445}
446
447/* Macros for inflate(): */
448
449/* check function to use adler32() for zlib or crc32() for gzip */
450#ifdef GUNZIP
451# define UPDATE(check, buf, len) \
452 (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
453#else
454# define UPDATE(check, buf, len) adler32(check, buf, len)
455#endif
456
457/* check macros for header crc */
458#ifdef GUNZIP
459# define CRC2(check, word) \
460 do { \
461 hbuf[0] = (unsigned char)(word); \
462 hbuf[1] = (unsigned char)((word) >> 8); \
463 check = crc32(check, hbuf, 2); \
464 } while (0)
465
466# define CRC4(check, word) \
467 do { \
468 hbuf[0] = (unsigned char)(word); \
469 hbuf[1] = (unsigned char)((word) >> 8); \
470 hbuf[2] = (unsigned char)((word) >> 16); \
471 hbuf[3] = (unsigned char)((word) >> 24); \
472 check = crc32(check, hbuf, 4); \
473 } while (0)
474#endif
475
476/* Load registers with state in inflate() for speed */
477#define LOAD() \
478 do { \
479 put = strm->next_out; \
480 left = strm->avail_out; \
481 next = strm->next_in; \
482 have = strm->avail_in; \
483 hold = state->hold; \
484 bits = state->bits; \
485 } while (0)
486
487/* Restore state from registers in inflate() */
488#define RESTORE() \
489 do { \
490 strm->next_out = put; \
491 strm->avail_out = left; \
492 strm->next_in = next; \
493 strm->avail_in = have; \
494 state->hold = hold; \
495 state->bits = bits; \
496 } while (0)
497
498/* Clear the input bit accumulator */
499#define INITBITS() \
500 do { \
501 hold = 0; \
502 bits = 0; \
503 } while (0)
504
505/* Get a byte of input into the bit accumulator, or return from inflate()
506 if there is no input available. */
507#define PULLBYTE() \
508 do { \
509 if (have == 0) goto inf_leave; \
510 have--; \
511 hold += (unsigned long)(*next++) << bits; \
512 bits += 8; \
513 } while (0)
514
515/* Assure that there are at least n bits in the bit accumulator. If there is
516 not enough available input to do that, then return from inflate(). */
517#define NEEDBITS(n) \
518 do { \
519 while (bits < (unsigned)(n)) \
520 PULLBYTE(); \
521 } while (0)
522
523/* Return the low n bits of the bit accumulator (n < 16) */
524#define BITS(n) \
525 ((unsigned)hold & ((1U << (n)) - 1))
526
527/* Remove n bits from the bit accumulator */
528#define DROPBITS(n) \
529 do { \
530 hold >>= (n); \
531 bits -= (unsigned)(n); \
532 } while (0)
533
534/* Remove zero to seven bits as needed to go to a byte boundary */
535#define BYTEBITS() \
536 do { \
537 hold >>= bits & 7; \
538 bits -= bits & 7; \
539 } while (0)
540
541/*
542 inflate() uses a state machine to process as much input data and generate as
543 much output data as possible before returning. The state machine is
544 structured roughly as follows:
545
546 for (;;) switch (state) {
547 ...
548 case STATEn:
549 if (not enough input data or output space to make progress)
550 return;
551 ... make progress ...
552 state = STATEm;
553 break;
554 ...
555 }
556
557 so when inflate() is called again, the same case is attempted again, and
558 if the appropriate resources are provided, the machine proceeds to the
559 next state. The NEEDBITS() macro is usually the way the state evaluates
560 whether it can proceed or should return. NEEDBITS() does the return if
561 the requested bits are not available. The typical use of the BITS macros
562 is:
563
564 NEEDBITS(n);
565 ... do something with BITS(n) ...
566 DROPBITS(n);
567
568 where NEEDBITS(n) either returns from inflate() if there isn't enough
569 input left to load n bits into the accumulator, or it continues. BITS(n)
570 gives the low n bits in the accumulator. When done, DROPBITS(n) drops
571 the low n bits off the accumulator. INITBITS() clears the accumulator
572 and sets the number of available bits to zero. BYTEBITS() discards just
573 enough bits to put the accumulator on a byte boundary. After BYTEBITS()
574 and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
575
576 NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
577 if there is no input available. The decoding of variable length codes uses
578 PULLBYTE() directly in order to pull just enough bytes to decode the next
579 code, and no more.
580
581 Some states loop until they get enough input, making sure that enough
582 state information is maintained to continue the loop where it left off
583 if NEEDBITS() returns in the loop. For example, want, need, and keep
584 would all have to actually be part of the saved state in case NEEDBITS()
585 returns:
586
587 case STATEw:
588 while (want < need) {
589 NEEDBITS(n);
590 keep[want++] = BITS(n);
591 DROPBITS(n);
592 }
593 state = STATEx;
594 case STATEx:
595
596 As shown above, if the next state is also the next case, then the break
597 is omitted.
598
599 A state may also return if there is not enough output space available to
600 complete that state. Those states are copying stored data, writing a
601 literal byte, and copying a matching string.
602
603 When returning, a "goto inf_leave" is used to update the total counters,
604 update the check value, and determine whether any progress has been made
605 during that inflate() call in order to return the proper return code.
606 Progress is defined as a change in either strm->avail_in or strm->avail_out.
607 When there is a window, goto inf_leave will update the window with the last
608 output written. If a goto inf_leave occurs in the middle of decompression
609 and there is no window currently, goto inf_leave will create one and copy
610 output to the window for the next call of inflate().
611
612 In this implementation, the flush parameter of inflate() only affects the
613 return code (per zlib.h). inflate() always writes as much as possible to
614 strm->next_out, given the space available and the provided input--the effect
615 documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
616 the allocation of and copying into a sliding window until necessary, which
617 provides the effect documented in zlib.h for Z_FINISH when the entire input
618 stream available. So the only thing the flush parameter actually does is:
619 when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
620 will return Z_BUF_ERROR if it has not reached the end of the stream.
621 */
622
623int ZEXPORT inflate(strm, flush)
624z_streamp strm;
625int flush;
626{
627 struct inflate_state FAR *state;
628 z_const unsigned char FAR *next; /* next input */
629 unsigned char FAR *put; /* next output */
630 unsigned have, left; /* available input and output */
631 unsigned long hold; /* bit buffer */
632 unsigned bits; /* bits in bit buffer */
633 unsigned in, out; /* save starting available input and output */
634 unsigned copy; /* number of stored or match bytes to copy */
635 unsigned char FAR *from; /* where to copy match bytes from */
636 code here; /* current decoding table entry */
637 code last; /* parent table entry */
638 unsigned len; /* length to copy for repeats, bits to drop */
639 int ret; /* return code */
640#ifdef GUNZIP
641 unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
642#endif
643 static const unsigned short order[19] = /* permutation of code lengths */
644 {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
645
646 if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
647 (strm->next_in == Z_NULL && strm->avail_in != 0))
648 return Z_STREAM_ERROR;
649
650 state = (struct inflate_state FAR *)strm->state;
651 if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
652 LOAD();
653 in = have;
654 out = left;
655 ret = Z_OK;
656 for (;;)
657 switch (state->mode) {
658 case HEAD:
659 if (state->wrap == 0) {
660 state->mode = TYPEDO;
661 break;
662 }
663 NEEDBITS(16);
664#ifdef GUNZIP
665 if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
666 if (state->wbits == 0)
667 state->wbits = 15;
668 state->check = crc32(0L, Z_NULL, 0);
669 CRC2(state->check, hold);
670 INITBITS();
671 state->mode = FLAGS;
672 break;
673 }
674 state->flags = 0; /* expect zlib header */
675 if (state->head != Z_NULL)
676 state->head->done = -1;
677 if (!(state->wrap & 1) || /* check if zlib header allowed */
678#else
679 if (
680#endif
681 ((BITS(8) << 8) + (hold >> 8)) % 31) {
682 strm->msg = (char *)"incorrect header check";
683 state->mode = BAD;
684 break;
685 }
686 if (BITS(4) != Z_DEFLATED) {
687 strm->msg = (char *)"unknown compression method";
688 state->mode = BAD;
689 break;
690 }
691 DROPBITS(4);
692 len = BITS(4) + 8;
693 if (state->wbits == 0)
694 state->wbits = len;
695 if (len > 15 || len > state->wbits) {
696 strm->msg = (char *)"invalid window size";
697 state->mode = BAD;
698 break;
699 }
700 state->dmax = 1U << len;
701 Tracev((stderr, "inflate: zlib header ok\n"));
702 strm->adler = state->check = adler32(0L, Z_NULL, 0);
703 state->mode = hold & 0x200 ? DICTID : TYPE;
704 INITBITS();
705 break;
706#ifdef GUNZIP
707 case FLAGS:
708 NEEDBITS(16);
709 state->flags = (int)(hold);
710 if ((state->flags & 0xff) != Z_DEFLATED) {
711 strm->msg = (char *)"unknown compression method";
712 state->mode = BAD;
713 break;
714 }
715 if (state->flags & 0xe000) {
716 strm->msg = (char *)"unknown header flags set";
717 state->mode = BAD;
718 break;
719 }
720 if (state->head != Z_NULL)
721 state->head->text = (int)((hold >> 8) & 1);
722 if ((state->flags & 0x0200) && (state->wrap & 4))
723 CRC2(state->check, hold);
724 INITBITS();
725 state->mode = TIME;
726 case TIME:
727 NEEDBITS(32);
728 if (state->head != Z_NULL)
729 state->head->time = hold;
730 if ((state->flags & 0x0200) && (state->wrap & 4))
731 CRC4(state->check, hold);
732 INITBITS();
733 state->mode = OS;
734 case OS:
735 NEEDBITS(16);
736 if (state->head != Z_NULL) {
737 state->head->xflags = (int)(hold & 0xff);
738 state->head->os = (int)(hold >> 8);
739 }
740 if ((state->flags & 0x0200) && (state->wrap & 4))
741 CRC2(state->check, hold);
742 INITBITS();
743 state->mode = EXLEN;
744 case EXLEN:
745 if (state->flags & 0x0400) {
746 NEEDBITS(16);
747 state->length = (unsigned)(hold);
748 if (state->head != Z_NULL)
749 state->head->extra_len = (unsigned)hold;
750 if ((state->flags & 0x0200) && (state->wrap & 4))
751 CRC2(state->check, hold);
752 INITBITS();
753 }
754 else if (state->head != Z_NULL)
755 state->head->extra = Z_NULL;
756 state->mode = EXTRA;
757 case EXTRA:
758 if (state->flags & 0x0400) {
759 copy = state->length;
760 if (copy > have) copy = have;
761 if (copy) {
762 if (state->head != Z_NULL &&
763 state->head->extra != Z_NULL) {
764 len = state->head->extra_len - state->length;
765 zmemcpy(state->head->extra + len, next,
766 len + copy > state->head->extra_max ?
767 state->head->extra_max - len : copy);
768 }
769 if ((state->flags & 0x0200) && (state->wrap & 4))
770 state->check = crc32(state->check, next, copy);
771 have -= copy;
772 next += copy;
773 state->length -= copy;
774 }
775 if (state->length) goto inf_leave;
776 }
777 state->length = 0;
778 state->mode = NAME;
779 case NAME:
780 if (state->flags & 0x0800) {
781 if (have == 0) goto inf_leave;
782 copy = 0;
783 do {
784 len = (unsigned)(next[copy++]);
785 if (state->head != Z_NULL &&
786 state->head->name != Z_NULL &&
787 state->length < state->head->name_max)
788 state->head->name[state->length++] = (Bytef)len;
789 } while (len && copy < have);
790 if ((state->flags & 0x0200) && (state->wrap & 4))
791 state->check = crc32(state->check, next, copy);
792 have -= copy;
793 next += copy;
794 if (len) goto inf_leave;
795 }
796 else if (state->head != Z_NULL)
797 state->head->name = Z_NULL;
798 state->length = 0;
799 state->mode = COMMENT;
800 case COMMENT:
801 if (state->flags & 0x1000) {
802 if (have == 0) goto inf_leave;
803 copy = 0;
804 do {
805 len = (unsigned)(next[copy++]);
806 if (state->head != Z_NULL &&
807 state->head->comment != Z_NULL &&
808 state->length < state->head->comm_max)
809 state->head->comment[state->length++] = (Bytef)len;
810 } while (len && copy < have);
811 if ((state->flags & 0x0200) && (state->wrap & 4))
812 state->check = crc32(state->check, next, copy);
813 have -= copy;
814 next += copy;
815 if (len) goto inf_leave;
816 }
817 else if (state->head != Z_NULL)
818 state->head->comment = Z_NULL;
819 state->mode = HCRC;
820 case HCRC:
821 if (state->flags & 0x0200) {
822 NEEDBITS(16);
823 if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
824 strm->msg = (char *)"header crc mismatch";
825 state->mode = BAD;
826 break;
827 }
828 INITBITS();
829 }
830 if (state->head != Z_NULL) {
831 state->head->hcrc = (int)((state->flags >> 9) & 1);
832 state->head->done = 1;
833 }
834 strm->adler = state->check = crc32(0L, Z_NULL, 0);
835 state->mode = TYPE;
836 break;
837#endif
838 case DICTID:
839 NEEDBITS(32);
840 strm->adler = state->check = ZSWAP32(hold);
841 INITBITS();
842 state->mode = DICT;
843 case DICT:
844 if (state->havedict == 0) {
845 RESTORE();
846 return Z_NEED_DICT;
847 }
848 strm->adler = state->check = adler32(0L, Z_NULL, 0);
849 state->mode = TYPE;
850 case TYPE:
851 if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
852 case TYPEDO:
853 if (state->last) {
854 BYTEBITS();
855 state->mode = CHECK;
856 break;
857 }
858 NEEDBITS(3);
859 state->last = BITS(1);
860 DROPBITS(1);
861 switch (BITS(2)) {
862 case 0: /* stored block */
863 Tracev((stderr, "inflate: stored block%s\n",
864 state->last ? " (last)" : ""));
865 state->mode = STORED;
866 break;
867 case 1: /* fixed block */
868 fixedtables(state);
869 Tracev((stderr, "inflate: fixed codes block%s\n",
870 state->last ? " (last)" : ""));
871 state->mode = LEN_; /* decode codes */
872 if (flush == Z_TREES) {
873 DROPBITS(2);
874 goto inf_leave;
875 }
876 break;
877 case 2: /* dynamic block */
878 Tracev((stderr, "inflate: dynamic codes block%s\n",
879 state->last ? " (last)" : ""));
880 state->mode = TABLE;
881 break;
882 case 3:
883 strm->msg = (char *)"invalid block type";
884 state->mode = BAD;
885 }
886 DROPBITS(2);
887 break;
888 case STORED:
889 BYTEBITS(); /* go to byte boundary */
890 NEEDBITS(32);
891 if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
892 strm->msg = (char *)"invalid stored block lengths";
893 state->mode = BAD;
894 break;
895 }
896 state->length = (unsigned)hold & 0xffff;
897 Tracev((stderr, "inflate: stored length %u\n",
898 state->length));
899 INITBITS();
900 state->mode = COPY_;
901 if (flush == Z_TREES) goto inf_leave;
902 case COPY_:
903 state->mode = COPY;
904 case COPY:
905 copy = state->length;
906 if (copy) {
907 if (copy > have) copy = have;
908 if (copy > left) copy = left;
909 if (copy == 0) goto inf_leave;
910 zmemcpy(put, next, copy);
911 have -= copy;
912 next += copy;
913 left -= copy;
914 put += copy;
915 state->length -= copy;
916 break;
917 }
918 Tracev((stderr, "inflate: stored end\n"));
919 state->mode = TYPE;
920 break;
921 case TABLE:
922 NEEDBITS(14);
923 state->nlen = BITS(5) + 257;
924 DROPBITS(5);
925 state->ndist = BITS(5) + 1;
926 DROPBITS(5);
927 state->ncode = BITS(4) + 4;
928 DROPBITS(4);
929#ifndef PKZIP_BUG_WORKAROUND
930 if (state->nlen > 286 || state->ndist > 30) {
931 strm->msg = (char *)"too many length or distance symbols";
932 state->mode = BAD;
933 break;
934 }
935#endif
936 Tracev((stderr, "inflate: table sizes ok\n"));
937 state->have = 0;
938 state->mode = LENLENS;
939 case LENLENS:
940 while (state->have < state->ncode) {
941 NEEDBITS(3);
942 state->lens[order[state->have++]] = (unsigned short)BITS(3);
943 DROPBITS(3);
944 }
945 while (state->have < 19)
946 state->lens[order[state->have++]] = 0;
947 state->next = state->codes;
948 state->lencode = (const code FAR *)(state->next);
949 state->lenbits = 7;
950 ret = inflate_table(CODES, state->lens, 19, &(state->next),
951 &(state->lenbits), state->work);
952 if (ret) {
953 strm->msg = (char *)"invalid code lengths set";
954 state->mode = BAD;
955 break;
956 }
957 Tracev((stderr, "inflate: code lengths ok\n"));
958 state->have = 0;
959 state->mode = CODELENS;
960 case CODELENS:
961 while (state->have < state->nlen + state->ndist) {
962 for (;;) {
963 here = state->lencode[BITS(state->lenbits)];
964 if ((unsigned)(here.bits) <= bits) break;
965 PULLBYTE();
966 }
967 if (here.val < 16) {
968 DROPBITS(here.bits);
969 state->lens[state->have++] = here.val;
970 }
971 else {
972 if (here.val == 16) {
973 NEEDBITS(here.bits + 2);
974 DROPBITS(here.bits);
975 if (state->have == 0) {
976 strm->msg = (char *)"invalid bit length repeat";
977 state->mode = BAD;
978 break;
979 }
980 len = state->lens[state->have - 1];
981 copy = 3 + BITS(2);
982 DROPBITS(2);
983 }
984 else if (here.val == 17) {
985 NEEDBITS(here.bits + 3);
986 DROPBITS(here.bits);
987 len = 0;
988 copy = 3 + BITS(3);
989 DROPBITS(3);
990 }
991 else {
992 NEEDBITS(here.bits + 7);
993 DROPBITS(here.bits);
994 len = 0;
995 copy = 11 + BITS(7);
996 DROPBITS(7);
997 }
998 if (state->have + copy > state->nlen + state->ndist) {
999 strm->msg = (char *)"invalid bit length repeat";
1000 state->mode = BAD;
1001 break;
1002 }
1003 while (copy--)
1004 state->lens[state->have++] = (unsigned short)len;
1005 }
1006 }
1007
1008 /* handle error breaks in while */
1009 if (state->mode == BAD) break;
1010
1011 /* check for end-of-block code (better have one) */
1012 if (state->lens[256] == 0) {
1013 strm->msg = (char *)"invalid code -- missing end-of-block";
1014 state->mode = BAD;
1015 break;
1016 }
1017
1018 /* build code tables -- note: do not change the lenbits or distbits
1019 values here (9 and 6) without reading the comments in inftrees.h
1020 concerning the ENOUGH constants, which depend on those values */
1021 state->next = state->codes;
1022 state->lencode = (const code FAR *)(state->next);
1023 state->lenbits = 9;
1024 ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1025 &(state->lenbits), state->work);
1026 if (ret) {
1027 strm->msg = (char *)"invalid literal/lengths set";
1028 state->mode = BAD;
1029 break;
1030 }
1031 state->distcode = (const code FAR *)(state->next);
1032 state->distbits = 6;
1033 ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1034 &(state->next), &(state->distbits), state->work);
1035 if (ret) {
1036 strm->msg = (char *)"invalid distances set";
1037 state->mode = BAD;
1038 break;
1039 }
1040 Tracev((stderr, "inflate: codes ok\n"));
1041 state->mode = LEN_;
1042 if (flush == Z_TREES) goto inf_leave;
1043 case LEN_:
1044 state->mode = LEN;
1045 case LEN:
1046 if (have >= INFLATE_FAST_MIN_INPUT &&
1047 left >= INFLATE_FAST_MIN_OUTPUT) {
1048 RESTORE();
1049 inflate_fast(strm, out);
1050 LOAD();
1051 if (state->mode == TYPE)
1052 state->back = -1;
1053 break;
1054 }
1055 state->back = 0;
1056 for (;;) {
1057 here = state->lencode[BITS(state->lenbits)];
1058 if ((unsigned)(here.bits) <= bits) break;
1059 PULLBYTE();
1060 }
1061 if (here.op && (here.op & 0xf0) == 0) {
1062 last = here;
1063 for (;;) {
1064 here = state->lencode[last.val +
1065 (BITS(last.bits + last.op) >> last.bits)];
1066 if ((unsigned)(last.bits + here.bits) <= bits) break;
1067 PULLBYTE();
1068 }
1069 DROPBITS(last.bits);
1070 state->back += last.bits;
1071 }
1072 DROPBITS(here.bits);
1073 state->back += here.bits;
1074 state->length = (unsigned)here.val;
1075 if ((int)(here.op) == 0) {
1076 Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1077 "inflate: literal '%c'\n" :
1078 "inflate: literal 0x%02x\n", here.val));
1079 state->mode = LIT;
1080 break;
1081 }
1082 if (here.op & 32) {
1083 Tracevv((stderr, "inflate: end of block\n"));
1084 state->back = -1;
1085 state->mode = TYPE;
1086 break;
1087 }
1088 if (here.op & 64) {
1089 strm->msg = (char *)"invalid literal/length code";
1090 state->mode = BAD;
1091 break;
1092 }
1093 state->extra = (unsigned)(here.op) & 15;
1094 state->mode = LENEXT;
1095 case LENEXT:
1096 if (state->extra) {
1097 NEEDBITS(state->extra);
1098 state->length += BITS(state->extra);
1099 DROPBITS(state->extra);
1100 state->back += state->extra;
1101 }
1102 Tracevv((stderr, "inflate: length %u\n", state->length));
1103 state->was = state->length;
1104 state->mode = DIST;
1105 case DIST:
1106 for (;;) {
1107 here = state->distcode[BITS(state->distbits)];
1108 if ((unsigned)(here.bits) <= bits) break;
1109 PULLBYTE();
1110 }
1111 if ((here.op & 0xf0) == 0) {
1112 last = here;
1113 for (;;) {
1114 here = state->distcode[last.val +
1115 (BITS(last.bits + last.op) >> last.bits)];
1116 if ((unsigned)(last.bits + here.bits) <= bits) break;
1117 PULLBYTE();
1118 }
1119 DROPBITS(last.bits);
1120 state->back += last.bits;
1121 }
1122 DROPBITS(here.bits);
1123 state->back += here.bits;
1124 if (here.op & 64) {
1125 strm->msg = (char *)"invalid distance code";
1126 state->mode = BAD;
1127 break;
1128 }
1129 state->offset = (unsigned)here.val;
1130 state->extra = (unsigned)(here.op) & 15;
1131 state->mode = DISTEXT;
1132 case DISTEXT:
1133 if (state->extra) {
1134 NEEDBITS(state->extra);
1135 state->offset += BITS(state->extra);
1136 DROPBITS(state->extra);
1137 state->back += state->extra;
1138 }
1139#ifdef INFLATE_STRICT
1140 if (state->offset > state->dmax) {
1141 strm->msg = (char *)"invalid distance too far back";
1142 state->mode = BAD;
1143 break;
1144 }
1145#endif
1146 Tracevv((stderr, "inflate: distance %u\n", state->offset));
1147 state->mode = MATCH;
1148 case MATCH:
1149 if (left == 0) goto inf_leave;
1150 copy = out - left;
1151 if (state->offset > copy) { /* copy from window */
1152 copy = state->offset - copy;
1153 if (copy > state->whave) {
1154 if (state->sane) {
1155 strm->msg = (char *)"invalid distance too far back";
1156 state->mode = BAD;
1157 break;
1158 }
1159#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1160 Trace((stderr, "inflate.c too far\n"));
1161 copy -= state->whave;
1162 if (copy > state->length) copy = state->length;
1163 if (copy > left) copy = left;
1164 left -= copy;
1165 state->length -= copy;
1166 do {
1167 *put++ = 0;
1168 } while (--copy);
1169 if (state->length == 0) state->mode = LEN;
1170 break;
1171#endif
1172 }
1173 if (copy > state->wnext) {
1174 copy -= state->wnext;
1175 from = state->window + (state->wsize - copy);
1176 }
1177 else
1178 from = state->window + (state->wnext - copy);
1179 if (copy > state->length) copy = state->length;
1180 }
1181 else { /* copy from output */
1182 from = put - state->offset;
1183 copy = state->length;
1184 }
1185 if (copy > left) copy = left;
1186 left -= copy;
1187 state->length -= copy;
1188 do {
1189 *put++ = *from++;
1190 } while (--copy);
1191 if (state->length == 0) state->mode = LEN;
1192 break;
1193 case LIT:
1194 if (left == 0) goto inf_leave;
1195 *put++ = (unsigned char)(state->length);
1196 left--;
1197 state->mode = LEN;
1198 break;
1199 case CHECK:
1200 if (state->wrap) {
1201 NEEDBITS(32);
1202 out -= left;
1203 strm->total_out += out;
1204 state->total += out;
1205 if ((state->wrap & 4) && out)
1206 strm->adler = state->check =
1207 UPDATE(state->check, put - out, out);
1208 out = left;
1209 if ((state->wrap & 4) && (
1210#ifdef GUNZIP
1211 state->flags ? hold :
1212#endif
1213 ZSWAP32(hold)) != state->check) {
1214 strm->msg = (char *)"incorrect data check";
1215 state->mode = BAD;
1216 break;
1217 }
1218 INITBITS();
1219 Tracev((stderr, "inflate: check matches trailer\n"));
1220 }
1221#ifdef GUNZIP
1222 state->mode = LENGTH;
1223 case LENGTH:
1224 if (state->wrap && state->flags) {
1225 NEEDBITS(32);
1226 if (hold != (state->total & 0xffffffffUL)) {
1227 strm->msg = (char *)"incorrect length check";
1228 state->mode = BAD;
1229 break;
1230 }
1231 INITBITS();
1232 Tracev((stderr, "inflate: length matches trailer\n"));
1233 }
1234#endif
1235 state->mode = DONE;
1236 case DONE:
1237 ret = Z_STREAM_END;
1238 goto inf_leave;
1239 case BAD:
1240 ret = Z_DATA_ERROR;
1241 goto inf_leave;
1242 case MEM:
1243 return Z_MEM_ERROR;
1244 case SYNC:
1245 default:
1246 return Z_STREAM_ERROR;
1247 }
1248
1249 /*
1250 Return from inflate(), updating the total counts and the check value.
1251 If there was no progress during the inflate() call, return a buffer
1252 error. Call updatewindow() to create and/or update the window state.
1253 Note: a memory error from inflate() is non-recoverable.
1254 */
1255 inf_leave:
1256 RESTORE();
1257 if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
1258 (state->mode < CHECK || flush != Z_FINISH)))
1259 if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
1260 state->mode = MEM;
1261 return Z_MEM_ERROR;
1262 }
1263 in -= strm->avail_in;
1264 out -= strm->avail_out;
1265 strm->total_in += in;
1266 strm->total_out += out;
1267 state->total += out;
1268 if ((state->wrap & 4) && out)
1269 strm->adler = state->check =
1270 UPDATE(state->check, strm->next_out - out, out);
1271 strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
1272 (state->mode == TYPE ? 128 : 0) +
1273 (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1274 if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1275 ret = Z_BUF_ERROR;
1276 return ret;
1277}
1278
1279int ZEXPORT inflateEnd(strm)
1280z_streamp strm;
1281{
1282 struct inflate_state FAR *state;
1283 if (inflateStateCheck(strm))
1284 return Z_STREAM_ERROR;
1285 state = (struct inflate_state FAR *)strm->state;
1286 if (state->window != Z_NULL) ZFREE(strm, state->window);
1287 ZFREE(strm, strm->state);
1288 strm->state = Z_NULL;
1289 Tracev((stderr, "inflate: end\n"));
1290 return Z_OK;
1291}
1292
1293int ZEXPORT inflateGetDictionary(strm, dictionary, dictLength)
1294z_streamp strm;
1295Bytef *dictionary;
1296uInt *dictLength;
1297{
1298 struct inflate_state FAR *state;
1299
1300 /* check state */
1301 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1302 state = (struct inflate_state FAR *)strm->state;
1303
1304 /* copy dictionary */
1305 if (state->whave && dictionary != Z_NULL) {
1306 zmemcpy(dictionary, state->window + state->wnext,
1307 state->whave - state->wnext);
1308 zmemcpy(dictionary + state->whave - state->wnext,
1309 state->window, state->wnext);
1310 }
1311 if (dictLength != Z_NULL)
1312 *dictLength = state->whave;
1313 return Z_OK;
1314}
1315
1316int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
1317z_streamp strm;
1318const Bytef *dictionary;
1319uInt dictLength;
1320{
1321 struct inflate_state FAR *state;
1322 unsigned long dictid;
1323 int ret;
1324
1325 /* check state */
1326 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1327 state = (struct inflate_state FAR *)strm->state;
1328 if (state->wrap != 0 && state->mode != DICT)
1329 return Z_STREAM_ERROR;
1330
1331 /* check for correct dictionary identifier */
1332 if (state->mode == DICT) {
1333 dictid = adler32(0L, Z_NULL, 0);
1334 dictid = adler32(dictid, dictionary, dictLength);
1335 if (dictid != state->check)
1336 return Z_DATA_ERROR;
1337 }
1338
1339 /* copy dictionary to window using updatewindow(), which will amend the
1340 existing dictionary if appropriate */
1341 ret = updatewindow(strm, dictionary + dictLength, dictLength);
1342 if (ret) {
1343 state->mode = MEM;
1344 return Z_MEM_ERROR;
1345 }
1346 state->havedict = 1;
1347 Tracev((stderr, "inflate: dictionary set\n"));
1348 return Z_OK;
1349}
1350
1351int ZEXPORT inflateGetHeader(strm, head)
1352z_streamp strm;
1353gz_headerp head;
1354{
1355 struct inflate_state FAR *state;
1356
1357 /* check state */
1358 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1359 state = (struct inflate_state FAR *)strm->state;
1360 if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
1361
1362 /* save header structure */
1363 state->head = head;
1364 head->done = 0;
1365 return Z_OK;
1366}
1367
1368/*
1369 Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found
1370 or when out of input. When called, *have is the number of pattern bytes
1371 found in order so far, in 0..3. On return *have is updated to the new
1372 state. If on return *have equals four, then the pattern was found and the
1373 return value is how many bytes were read including the last byte of the
1374 pattern. If *have is less than four, then the pattern has not been found
1375 yet and the return value is len. In the latter case, syncsearch() can be
1376 called again with more data and the *have state. *have is initialized to
1377 zero for the first call.
1378 */
1379local unsigned syncsearch(have, buf, len)
1380unsigned FAR *have;
1381const unsigned char FAR *buf;
1382unsigned len;
1383{
1384 unsigned got;
1385 unsigned next;
1386
1387 got = *have;
1388 next = 0;
1389 while (next < len && got < 4) {
1390 if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
1391 got++;
1392 else if (buf[next])
1393 got = 0;
1394 else
1395 got = 4 - got;
1396 next++;
1397 }
1398 *have = got;
1399 return next;
1400}
1401
1402int ZEXPORT inflateSync(strm)
1403z_streamp strm;
1404{
1405 unsigned len; /* number of bytes to look at or looked at */
1406 unsigned long in, out; /* temporary to save total_in and total_out */
1407 unsigned char buf[4]; /* to restore bit buffer to byte string */
1408 struct inflate_state FAR *state;
1409
1410 /* check parameters */
1411 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1412 state = (struct inflate_state FAR *)strm->state;
1413 if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
1414
1415 /* if first time, start search in bit buffer */
1416 if (state->mode != SYNC) {
1417 state->mode = SYNC;
1418 state->hold <<= state->bits & 7;
1419 state->bits -= state->bits & 7;
1420 len = 0;
1421 while (state->bits >= 8) {
1422 buf[len++] = (unsigned char)(state->hold);
1423 state->hold >>= 8;
1424 state->bits -= 8;
1425 }
1426 state->have = 0;
1427 syncsearch(&(state->have), buf, len);
1428 }
1429
1430 /* search available input */
1431 len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
1432 strm->avail_in -= len;
1433 strm->next_in += len;
1434 strm->total_in += len;
1435
1436 /* return no joy or set up to restart inflate() on a new block */
1437 if (state->have != 4) return Z_DATA_ERROR;
1438 in = strm->total_in; out = strm->total_out;
1439 inflateReset(strm);
1440 strm->total_in = in; strm->total_out = out;
1441 state->mode = TYPE;
1442 return Z_OK;
1443}
1444
1445/*
1446 Returns true if inflate is currently at the end of a block generated by
1447 Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
1448 implementation to provide an additional safety check. PPP uses
1449 Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
1450 block. When decompressing, PPP checks that at the end of input packet,
1451 inflate is waiting for these length bytes.
1452 */
1453int ZEXPORT inflateSyncPoint(strm)
1454z_streamp strm;
1455{
1456 struct inflate_state FAR *state;
1457
1458 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1459 state = (struct inflate_state FAR *)strm->state;
1460 return state->mode == STORED && state->bits == 0;
1461}
1462
1463int ZEXPORT inflateCopy(dest, source)
1464z_streamp dest;
1465z_streamp source;
1466{
1467 struct inflate_state FAR *state;
1468 struct inflate_state FAR *copy;
1469 unsigned char FAR *window;
1470 unsigned wsize;
1471
1472 /* check input */
1473 if (inflateStateCheck(source) || dest == Z_NULL)
1474 return Z_STREAM_ERROR;
1475 state = (struct inflate_state FAR *)source->state;
1476
1477 /* allocate space */
1478 copy = (struct inflate_state FAR *)
1479 ZALLOC(source, 1, sizeof(struct inflate_state));
1480 if (copy == Z_NULL) return Z_MEM_ERROR;
1481 window = Z_NULL;
1482 if (state->window != Z_NULL) {
1483 window = (unsigned char FAR *)
1484 ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
1485 if (window == Z_NULL) {
1486 ZFREE(source, copy);
1487 return Z_MEM_ERROR;
1488 }
1489 }
1490
1491 /* copy state */
1492 zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
1493 zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state));
1494 copy->strm = dest;
1495 if (state->lencode >= state->codes &&
1496 state->lencode <= state->codes + ENOUGH - 1) {
1497 copy->lencode = copy->codes + (state->lencode - state->codes);
1498 copy->distcode = copy->codes + (state->distcode - state->codes);
1499 }
1500 copy->next = copy->codes + (state->next - state->codes);
1501 if (window != Z_NULL) {
1502 wsize = 1U << state->wbits;
1503 zmemcpy(window, state->window, wsize);
1504 }
1505 copy->window = window;
1506 dest->state = (struct internal_state FAR *)copy;
1507 return Z_OK;
1508}
1509
1510int ZEXPORT inflateUndermine(strm, subvert)
1511z_streamp strm;
1512int subvert;
1513{
1514 struct inflate_state FAR *state;
1515
1516 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1517 state = (struct inflate_state FAR *)strm->state;
1518#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1519 state->sane = !subvert;
1520 return Z_OK;
1521#else
1522 (void)subvert;
1523 state->sane = 1;
1524 return Z_DATA_ERROR;
1525#endif
1526}
1527
1528int ZEXPORT inflateValidate(strm, check)
1529z_streamp strm;
1530int check;
1531{
1532 struct inflate_state FAR *state;
1533
1534 if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1535 state = (struct inflate_state FAR *)strm->state;
1536 if (check)
1537 state->wrap |= 4;
1538 else
1539 state->wrap &= ~4;
1540 return Z_OK;
1541}
1542
1543long ZEXPORT inflateMark(strm)
1544z_streamp strm;
1545{
1546 struct inflate_state FAR *state;
1547
1548 if (inflateStateCheck(strm))
1549 return -(1L << 16);
1550 state = (struct inflate_state FAR *)strm->state;
1551 return (long)(((unsigned long)((long)state->back)) << 16) +
1552 (state->mode == COPY ? state->length :
1553 (state->mode == MATCH ? state->was - state->length : 0));
1554}
1555
1556unsigned long ZEXPORT inflateCodesUsed(strm)
1557z_streamp strm;
1558{
1559 struct inflate_state FAR *state;
1560 if (inflateStateCheck(strm)) return (unsigned long)-1;
1561 state = (struct inflate_state FAR *)strm->state;
1562 return (unsigned long)(state->next - state->codes);
1563}
1564