Update zlib from 1.2.3 to 1.2.5
[reactos.git] / reactos / lib / 3rdparty / zlib / inflate.c
1 /* inflate.c -- zlib decompression
2 * Copyright (C) 1995-2010 Mark Adler
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
5
6 /*
7 * Change history:
8 *
9 * 1.2.beta0 24 Nov 2002
10 * - First version -- complete rewrite of inflate to simplify code, avoid
11 * creation of window when not needed, minimize use of window when it is
12 * needed, make inffast.c even faster, implement gzip decoding, and to
13 * improve code readability and style over the previous zlib inflate code
14 *
15 * 1.2.beta1 25 Nov 2002
16 * - Use pointers for available input and output checking in inffast.c
17 * - Remove input and output counters in inffast.c
18 * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
19 * - Remove unnecessary second byte pull from length extra in inffast.c
20 * - Unroll direct copy to three copies per loop in inffast.c
21 *
22 * 1.2.beta2 4 Dec 2002
23 * - Change external routine names to reduce potential conflicts
24 * - Correct filename to inffixed.h for fixed tables in inflate.c
25 * - Make hbuf[] unsigned char to match parameter type in inflate.c
26 * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
27 * to avoid negation problem on Alphas (64 bit) in inflate.c
28 *
29 * 1.2.beta3 22 Dec 2002
30 * - Add comments on state->bits assertion in inffast.c
31 * - Add comments on op field in inftrees.h
32 * - Fix bug in reuse of allocated window after inflateReset()
33 * - Remove bit fields--back to byte structure for speed
34 * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
35 * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
36 * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
37 * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
38 * - Use local copies of stream next and avail values, as well as local bit
39 * buffer and bit count in inflate()--for speed when inflate_fast() not used
40 *
41 * 1.2.beta4 1 Jan 2003
42 * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
43 * - Move a comment on output buffer sizes from inffast.c to inflate.c
44 * - Add comments in inffast.c to introduce the inflate_fast() routine
45 * - Rearrange window copies in inflate_fast() for speed and simplification
46 * - Unroll last copy for window match in inflate_fast()
47 * - Use local copies of window variables in inflate_fast() for speed
48 * - Pull out common wnext == 0 case for speed in inflate_fast()
49 * - Make op and len in inflate_fast() unsigned for consistency
50 * - Add FAR to lcode and dcode declarations in inflate_fast()
51 * - Simplified bad distance check in inflate_fast()
52 * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
53 * source file infback.c to provide a call-back interface to inflate for
54 * programs like gzip and unzip -- uses window as output buffer to avoid
55 * window copying
56 *
57 * 1.2.beta5 1 Jan 2003
58 * - Improved inflateBack() interface to allow the caller to provide initial
59 * input in strm.
60 * - Fixed stored blocks bug in inflateBack()
61 *
62 * 1.2.beta6 4 Jan 2003
63 * - Added comments in inffast.c on effectiveness of POSTINC
64 * - Typecasting all around to reduce compiler warnings
65 * - Changed loops from while (1) or do {} while (1) to for (;;), again to
66 * make compilers happy
67 * - Changed type of window in inflateBackInit() to unsigned char *
68 *
69 * 1.2.beta7 27 Jan 2003
70 * - Changed many types to unsigned or unsigned short to avoid warnings
71 * - Added inflateCopy() function
72 *
73 * 1.2.0 9 Mar 2003
74 * - Changed inflateBack() interface to provide separate opaque descriptors
75 * for the in() and out() functions
76 * - Changed inflateBack() argument and in_func typedef to swap the length
77 * and buffer address return values for the input function
78 * - Check next_in and next_out for Z_NULL on entry to inflate()
79 *
80 * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
81 */
82
83 #include "zutil.h"
84 #include "inftrees.h"
85 #include "inflate.h"
86 #include "inffast.h"
87
88 #ifdef MAKEFIXED
89 # ifndef BUILDFIXED
90 # define BUILDFIXED
91 # endif
92 #endif
93
94 /* function prototypes */
95 local void fixedtables OF((struct inflate_state FAR *state));
96 local int updatewindow OF((z_streamp strm, unsigned out));
97 #ifdef BUILDFIXED
98 void makefixed OF((void));
99 #endif
100 local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf,
101 unsigned len));
102
103 int ZEXPORT inflateReset(strm)
104 z_streamp strm;
105 {
106 struct inflate_state FAR *state;
107
108 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
109 state = (struct inflate_state FAR *)strm->state;
110 strm->total_in = strm->total_out = state->total = 0;
111 strm->msg = Z_NULL;
112 strm->adler = 1; /* to support ill-conceived Java test suite */
113 state->mode = HEAD;
114 state->last = 0;
115 state->havedict = 0;
116 state->dmax = 32768U;
117 state->head = Z_NULL;
118 state->wsize = 0;
119 state->whave = 0;
120 state->wnext = 0;
121 state->hold = 0;
122 state->bits = 0;
123 state->lencode = state->distcode = state->next = state->codes;
124 state->sane = 1;
125 state->back = -1;
126 Tracev((stderr, "inflate: reset\n"));
127 return Z_OK;
128 }
129
130 int ZEXPORT inflateReset2(strm, windowBits)
131 z_streamp strm;
132 int windowBits;
133 {
134 int wrap;
135 struct inflate_state FAR *state;
136
137 /* get the state */
138 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
139 state = (struct inflate_state FAR *)strm->state;
140
141 /* extract wrap request from windowBits parameter */
142 if (windowBits < 0) {
143 wrap = 0;
144 windowBits = -windowBits;
145 }
146 else {
147 wrap = (windowBits >> 4) + 1;
148 #ifdef GUNZIP
149 if (windowBits < 48)
150 windowBits &= 15;
151 #endif
152 }
153
154 /* set number of window bits, free window if different */
155 if (windowBits && (windowBits < 8 || windowBits > 15))
156 return Z_STREAM_ERROR;
157 if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
158 ZFREE(strm, state->window);
159 state->window = Z_NULL;
160 }
161
162 /* update state and reset the rest of it */
163 state->wrap = wrap;
164 state->wbits = (unsigned)windowBits;
165 return inflateReset(strm);
166 }
167
168 int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
169 z_streamp strm;
170 int windowBits;
171 const char *version;
172 int stream_size;
173 {
174 int ret;
175 struct inflate_state FAR *state;
176
177 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
178 stream_size != (int)(sizeof(z_stream)))
179 return Z_VERSION_ERROR;
180 if (strm == Z_NULL) return Z_STREAM_ERROR;
181 strm->msg = Z_NULL; /* in case we return an error */
182 if (strm->zalloc == (alloc_func)0) {
183 strm->zalloc = zcalloc;
184 strm->opaque = (voidpf)0;
185 }
186 if (strm->zfree == (free_func)0) strm->zfree = zcfree;
187 state = (struct inflate_state FAR *)
188 ZALLOC(strm, 1, sizeof(struct inflate_state));
189 if (state == Z_NULL) return Z_MEM_ERROR;
190 Tracev((stderr, "inflate: allocated\n"));
191 strm->state = (struct internal_state FAR *)state;
192 state->window = Z_NULL;
193 ret = inflateReset2(strm, windowBits);
194 if (ret != Z_OK) {
195 ZFREE(strm, state);
196 strm->state = Z_NULL;
197 }
198 return ret;
199 }
200
201 int ZEXPORT inflateInit_(strm, version, stream_size)
202 z_streamp strm;
203 const char *version;
204 int stream_size;
205 {
206 return inflateInit2_(strm, DEF_WBITS, version, stream_size);
207 }
208
209 int ZEXPORT inflatePrime(strm, bits, value)
210 z_streamp strm;
211 int bits;
212 int value;
213 {
214 struct inflate_state FAR *state;
215
216 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
217 state = (struct inflate_state FAR *)strm->state;
218 if (bits < 0) {
219 state->hold = 0;
220 state->bits = 0;
221 return Z_OK;
222 }
223 if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
224 value &= (1L << bits) - 1;
225 state->hold += value << state->bits;
226 state->bits += bits;
227 return Z_OK;
228 }
229
230 /*
231 Return state with length and distance decoding tables and index sizes set to
232 fixed code decoding. Normally this returns fixed tables from inffixed.h.
233 If BUILDFIXED is defined, then instead this routine builds the tables the
234 first time it's called, and returns those tables the first time and
235 thereafter. This reduces the size of the code by about 2K bytes, in
236 exchange for a little execution time. However, BUILDFIXED should not be
237 used for threaded applications, since the rewriting of the tables and virgin
238 may not be thread-safe.
239 */
240 local void fixedtables(state)
241 struct inflate_state FAR *state;
242 {
243 #ifdef BUILDFIXED
244 static int virgin = 1;
245 static code *lenfix, *distfix;
246 static code fixed[544];
247
248 /* build fixed huffman tables if first call (may not be thread safe) */
249 if (virgin) {
250 unsigned sym, bits;
251 static code *next;
252
253 /* literal/length table */
254 sym = 0;
255 while (sym < 144) state->lens[sym++] = 8;
256 while (sym < 256) state->lens[sym++] = 9;
257 while (sym < 280) state->lens[sym++] = 7;
258 while (sym < 288) state->lens[sym++] = 8;
259 next = fixed;
260 lenfix = next;
261 bits = 9;
262 inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
263
264 /* distance table */
265 sym = 0;
266 while (sym < 32) state->lens[sym++] = 5;
267 distfix = next;
268 bits = 5;
269 inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
270
271 /* do this just once */
272 virgin = 0;
273 }
274 #else /* !BUILDFIXED */
275 # include "inffixed.h"
276 #endif /* BUILDFIXED */
277 state->lencode = lenfix;
278 state->lenbits = 9;
279 state->distcode = distfix;
280 state->distbits = 5;
281 }
282
283 #ifdef MAKEFIXED
284 #include <stdio.h>
285
286 /*
287 Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also
288 defines BUILDFIXED, so the tables are built on the fly. makefixed() writes
289 those tables to stdout, which would be piped to inffixed.h. A small program
290 can simply call makefixed to do this:
291
292 void makefixed(void);
293
294 int main(void)
295 {
296 makefixed();
297 return 0;
298 }
299
300 Then that can be linked with zlib built with MAKEFIXED defined and run:
301
302 a.out > inffixed.h
303 */
304 void makefixed()
305 {
306 unsigned low, size;
307 struct inflate_state state;
308
309 fixedtables(&state);
310 puts(" /* inffixed.h -- table for decoding fixed codes");
311 puts(" * Generated automatically by makefixed().");
312 puts(" */");
313 puts("");
314 puts(" /* WARNING: this file should *not* be used by applications.");
315 puts(" It is part of the implementation of this library and is");
316 puts(" subject to change. Applications should only use zlib.h.");
317 puts(" */");
318 puts("");
319 size = 1U << 9;
320 printf(" static const code lenfix[%u] = {", size);
321 low = 0;
322 for (;;) {
323 if ((low % 7) == 0) printf("\n ");
324 printf("{%u,%u,%d}", state.lencode[low].op, state.lencode[low].bits,
325 state.lencode[low].val);
326 if (++low == size) break;
327 putchar(',');
328 }
329 puts("\n };");
330 size = 1U << 5;
331 printf("\n static const code distfix[%u] = {", size);
332 low = 0;
333 for (;;) {
334 if ((low % 6) == 0) printf("\n ");
335 printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
336 state.distcode[low].val);
337 if (++low == size) break;
338 putchar(',');
339 }
340 puts("\n };");
341 }
342 #endif /* MAKEFIXED */
343
344 /*
345 Update the window with the last wsize (normally 32K) bytes written before
346 returning. If window does not exist yet, create it. This is only called
347 when a window is already in use, or when output has been written during this
348 inflate call, but the end of the deflate stream has not been reached yet.
349 It is also called to create a window for dictionary data when a dictionary
350 is loaded.
351
352 Providing output buffers larger than 32K to inflate() should provide a speed
353 advantage, since only the last 32K of output is copied to the sliding window
354 upon return from inflate(), and since all distances after the first 32K of
355 output will fall in the output data, making match copies simpler and faster.
356 The advantage may be dependent on the size of the processor's data caches.
357 */
358 local int updatewindow(strm, out)
359 z_streamp strm;
360 unsigned out;
361 {
362 struct inflate_state FAR *state;
363 unsigned copy, dist;
364
365 state = (struct inflate_state FAR *)strm->state;
366
367 /* if it hasn't been done already, allocate space for the window */
368 if (state->window == Z_NULL) {
369 state->window = (unsigned char FAR *)
370 ZALLOC(strm, 1U << state->wbits,
371 sizeof(unsigned char));
372 if (state->window == Z_NULL) return 1;
373 }
374
375 /* if window not in use yet, initialize */
376 if (state->wsize == 0) {
377 state->wsize = 1U << state->wbits;
378 state->wnext = 0;
379 state->whave = 0;
380 }
381
382 /* copy state->wsize or less output bytes into the circular window */
383 copy = out - strm->avail_out;
384 if (copy >= state->wsize) {
385 zmemcpy(state->window, strm->next_out - state->wsize, state->wsize);
386 state->wnext = 0;
387 state->whave = state->wsize;
388 }
389 else {
390 dist = state->wsize - state->wnext;
391 if (dist > copy) dist = copy;
392 zmemcpy(state->window + state->wnext, strm->next_out - copy, dist);
393 copy -= dist;
394 if (copy) {
395 zmemcpy(state->window, strm->next_out - copy, copy);
396 state->wnext = copy;
397 state->whave = state->wsize;
398 }
399 else {
400 state->wnext += dist;
401 if (state->wnext == state->wsize) state->wnext = 0;
402 if (state->whave < state->wsize) state->whave += dist;
403 }
404 }
405 return 0;
406 }
407
408 /* Macros for inflate(): */
409
410 /* check function to use adler32() for zlib or crc32() for gzip */
411 #ifdef GUNZIP
412 # define UPDATE(check, buf, len) \
413 (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
414 #else
415 # define UPDATE(check, buf, len) adler32(check, buf, len)
416 #endif
417
418 /* check macros for header crc */
419 #ifdef GUNZIP
420 # define CRC2(check, word) \
421 do { \
422 hbuf[0] = (unsigned char)(word); \
423 hbuf[1] = (unsigned char)((word) >> 8); \
424 check = crc32(check, hbuf, 2); \
425 } while (0)
426
427 # define CRC4(check, word) \
428 do { \
429 hbuf[0] = (unsigned char)(word); \
430 hbuf[1] = (unsigned char)((word) >> 8); \
431 hbuf[2] = (unsigned char)((word) >> 16); \
432 hbuf[3] = (unsigned char)((word) >> 24); \
433 check = crc32(check, hbuf, 4); \
434 } while (0)
435 #endif
436
437 /* Load registers with state in inflate() for speed */
438 #define LOAD() \
439 do { \
440 put = strm->next_out; \
441 left = strm->avail_out; \
442 next = strm->next_in; \
443 have = strm->avail_in; \
444 hold = state->hold; \
445 bits = state->bits; \
446 } while (0)
447
448 /* Restore state from registers in inflate() */
449 #define RESTORE() \
450 do { \
451 strm->next_out = put; \
452 strm->avail_out = left; \
453 strm->next_in = next; \
454 strm->avail_in = have; \
455 state->hold = hold; \
456 state->bits = bits; \
457 } while (0)
458
459 /* Clear the input bit accumulator */
460 #define INITBITS() \
461 do { \
462 hold = 0; \
463 bits = 0; \
464 } while (0)
465
466 /* Get a byte of input into the bit accumulator, or return from inflate()
467 if there is no input available. */
468 #define PULLBYTE() \
469 do { \
470 if (have == 0) goto inf_leave; \
471 have--; \
472 hold += (unsigned long)(*next++) << bits; \
473 bits += 8; \
474 } while (0)
475
476 /* Assure that there are at least n bits in the bit accumulator. If there is
477 not enough available input to do that, then return from inflate(). */
478 #define NEEDBITS(n) \
479 do { \
480 while (bits < (unsigned)(n)) \
481 PULLBYTE(); \
482 } while (0)
483
484 /* Return the low n bits of the bit accumulator (n < 16) */
485 #define BITS(n) \
486 ((unsigned)hold & ((1U << (n)) - 1))
487
488 /* Remove n bits from the bit accumulator */
489 #define DROPBITS(n) \
490 do { \
491 hold >>= (n); \
492 bits -= (unsigned)(n); \
493 } while (0)
494
495 /* Remove zero to seven bits as needed to go to a byte boundary */
496 #define BYTEBITS() \
497 do { \
498 hold >>= bits & 7; \
499 bits -= bits & 7; \
500 } while (0)
501
502 /* Reverse the bytes in a 32-bit value */
503 #define REVERSE(q) \
504 ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
505 (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
506
507 /*
508 inflate() uses a state machine to process as much input data and generate as
509 much output data as possible before returning. The state machine is
510 structured roughly as follows:
511
512 for (;;) switch (state) {
513 ...
514 case STATEn:
515 if (not enough input data or output space to make progress)
516 return;
517 ... make progress ...
518 state = STATEm;
519 break;
520 ...
521 }
522
523 so when inflate() is called again, the same case is attempted again, and
524 if the appropriate resources are provided, the machine proceeds to the
525 next state. The NEEDBITS() macro is usually the way the state evaluates
526 whether it can proceed or should return. NEEDBITS() does the return if
527 the requested bits are not available. The typical use of the BITS macros
528 is:
529
530 NEEDBITS(n);
531 ... do something with BITS(n) ...
532 DROPBITS(n);
533
534 where NEEDBITS(n) either returns from inflate() if there isn't enough
535 input left to load n bits into the accumulator, or it continues. BITS(n)
536 gives the low n bits in the accumulator. When done, DROPBITS(n) drops
537 the low n bits off the accumulator. INITBITS() clears the accumulator
538 and sets the number of available bits to zero. BYTEBITS() discards just
539 enough bits to put the accumulator on a byte boundary. After BYTEBITS()
540 and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
541
542 NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
543 if there is no input available. The decoding of variable length codes uses
544 PULLBYTE() directly in order to pull just enough bytes to decode the next
545 code, and no more.
546
547 Some states loop until they get enough input, making sure that enough
548 state information is maintained to continue the loop where it left off
549 if NEEDBITS() returns in the loop. For example, want, need, and keep
550 would all have to actually be part of the saved state in case NEEDBITS()
551 returns:
552
553 case STATEw:
554 while (want < need) {
555 NEEDBITS(n);
556 keep[want++] = BITS(n);
557 DROPBITS(n);
558 }
559 state = STATEx;
560 case STATEx:
561
562 As shown above, if the next state is also the next case, then the break
563 is omitted.
564
565 A state may also return if there is not enough output space available to
566 complete that state. Those states are copying stored data, writing a
567 literal byte, and copying a matching string.
568
569 When returning, a "goto inf_leave" is used to update the total counters,
570 update the check value, and determine whether any progress has been made
571 during that inflate() call in order to return the proper return code.
572 Progress is defined as a change in either strm->avail_in or strm->avail_out.
573 When there is a window, goto inf_leave will update the window with the last
574 output written. If a goto inf_leave occurs in the middle of decompression
575 and there is no window currently, goto inf_leave will create one and copy
576 output to the window for the next call of inflate().
577
578 In this implementation, the flush parameter of inflate() only affects the
579 return code (per zlib.h). inflate() always writes as much as possible to
580 strm->next_out, given the space available and the provided input--the effect
581 documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
582 the allocation of and copying into a sliding window until necessary, which
583 provides the effect documented in zlib.h for Z_FINISH when the entire input
584 stream available. So the only thing the flush parameter actually does is:
585 when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
586 will return Z_BUF_ERROR if it has not reached the end of the stream.
587 */
588
589 int ZEXPORT inflate(strm, flush)
590 z_streamp strm;
591 int flush;
592 {
593 struct inflate_state FAR *state;
594 unsigned char FAR *next; /* next input */
595 unsigned char FAR *put; /* next output */
596 unsigned have, left; /* available input and output */
597 unsigned long hold; /* bit buffer */
598 unsigned bits; /* bits in bit buffer */
599 unsigned in, out; /* save starting available input and output */
600 unsigned copy; /* number of stored or match bytes to copy */
601 unsigned char FAR *from; /* where to copy match bytes from */
602 code here; /* current decoding table entry */
603 code last; /* parent table entry */
604 unsigned len; /* length to copy for repeats, bits to drop */
605 int ret; /* return code */
606 #ifdef GUNZIP
607 unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
608 #endif
609 static const unsigned short order[19] = /* permutation of code lengths */
610 {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
611
612 if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL ||
613 (strm->next_in == Z_NULL && strm->avail_in != 0))
614 return Z_STREAM_ERROR;
615
616 state = (struct inflate_state FAR *)strm->state;
617 if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
618 LOAD();
619 in = have;
620 out = left;
621 ret = Z_OK;
622 for (;;)
623 switch (state->mode) {
624 case HEAD:
625 if (state->wrap == 0) {
626 state->mode = TYPEDO;
627 break;
628 }
629 NEEDBITS(16);
630 #ifdef GUNZIP
631 if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
632 state->check = crc32(0L, Z_NULL, 0);
633 CRC2(state->check, hold);
634 INITBITS();
635 state->mode = FLAGS;
636 break;
637 }
638 state->flags = 0; /* expect zlib header */
639 if (state->head != Z_NULL)
640 state->head->done = -1;
641 if (!(state->wrap & 1) || /* check if zlib header allowed */
642 #else
643 if (
644 #endif
645 ((BITS(8) << 8) + (hold >> 8)) % 31) {
646 strm->msg = (char *)"incorrect header check";
647 state->mode = BAD;
648 break;
649 }
650 if (BITS(4) != Z_DEFLATED) {
651 strm->msg = (char *)"unknown compression method";
652 state->mode = BAD;
653 break;
654 }
655 DROPBITS(4);
656 len = BITS(4) + 8;
657 if (state->wbits == 0)
658 state->wbits = len;
659 else if (len > state->wbits) {
660 strm->msg = (char *)"invalid window size";
661 state->mode = BAD;
662 break;
663 }
664 state->dmax = 1U << len;
665 Tracev((stderr, "inflate: zlib header ok\n"));
666 strm->adler = state->check = adler32(0L, Z_NULL, 0);
667 state->mode = hold & 0x200 ? DICTID : TYPE;
668 INITBITS();
669 break;
670 #ifdef GUNZIP
671 case FLAGS:
672 NEEDBITS(16);
673 state->flags = (int)(hold);
674 if ((state->flags & 0xff) != Z_DEFLATED) {
675 strm->msg = (char *)"unknown compression method";
676 state->mode = BAD;
677 break;
678 }
679 if (state->flags & 0xe000) {
680 strm->msg = (char *)"unknown header flags set";
681 state->mode = BAD;
682 break;
683 }
684 if (state->head != Z_NULL)
685 state->head->text = (int)((hold >> 8) & 1);
686 if (state->flags & 0x0200) CRC2(state->check, hold);
687 INITBITS();
688 state->mode = TIME;
689 case TIME:
690 NEEDBITS(32);
691 if (state->head != Z_NULL)
692 state->head->time = hold;
693 if (state->flags & 0x0200) CRC4(state->check, hold);
694 INITBITS();
695 state->mode = OS;
696 case OS:
697 NEEDBITS(16);
698 if (state->head != Z_NULL) {
699 state->head->xflags = (int)(hold & 0xff);
700 state->head->os = (int)(hold >> 8);
701 }
702 if (state->flags & 0x0200) CRC2(state->check, hold);
703 INITBITS();
704 state->mode = EXLEN;
705 case EXLEN:
706 if (state->flags & 0x0400) {
707 NEEDBITS(16);
708 state->length = (unsigned)(hold);
709 if (state->head != Z_NULL)
710 state->head->extra_len = (unsigned)hold;
711 if (state->flags & 0x0200) CRC2(state->check, hold);
712 INITBITS();
713 }
714 else if (state->head != Z_NULL)
715 state->head->extra = Z_NULL;
716 state->mode = EXTRA;
717 case EXTRA:
718 if (state->flags & 0x0400) {
719 copy = state->length;
720 if (copy > have) copy = have;
721 if (copy) {
722 if (state->head != Z_NULL &&
723 state->head->extra != Z_NULL) {
724 len = state->head->extra_len - state->length;
725 zmemcpy(state->head->extra + len, next,
726 len + copy > state->head->extra_max ?
727 state->head->extra_max - len : copy);
728 }
729 if (state->flags & 0x0200)
730 state->check = crc32(state->check, next, copy);
731 have -= copy;
732 next += copy;
733 state->length -= copy;
734 }
735 if (state->length) goto inf_leave;
736 }
737 state->length = 0;
738 state->mode = NAME;
739 case NAME:
740 if (state->flags & 0x0800) {
741 if (have == 0) goto inf_leave;
742 copy = 0;
743 do {
744 len = (unsigned)(next[copy++]);
745 if (state->head != Z_NULL &&
746 state->head->name != Z_NULL &&
747 state->length < state->head->name_max)
748 state->head->name[state->length++] = len;
749 } while (len && copy < have);
750 if (state->flags & 0x0200)
751 state->check = crc32(state->check, next, copy);
752 have -= copy;
753 next += copy;
754 if (len) goto inf_leave;
755 }
756 else if (state->head != Z_NULL)
757 state->head->name = Z_NULL;
758 state->length = 0;
759 state->mode = COMMENT;
760 case COMMENT:
761 if (state->flags & 0x1000) {
762 if (have == 0) goto inf_leave;
763 copy = 0;
764 do {
765 len = (unsigned)(next[copy++]);
766 if (state->head != Z_NULL &&
767 state->head->comment != Z_NULL &&
768 state->length < state->head->comm_max)
769 state->head->comment[state->length++] = len;
770 } while (len && copy < have);
771 if (state->flags & 0x0200)
772 state->check = crc32(state->check, next, copy);
773 have -= copy;
774 next += copy;
775 if (len) goto inf_leave;
776 }
777 else if (state->head != Z_NULL)
778 state->head->comment = Z_NULL;
779 state->mode = HCRC;
780 case HCRC:
781 if (state->flags & 0x0200) {
782 NEEDBITS(16);
783 if (hold != (state->check & 0xffff)) {
784 strm->msg = (char *)"header crc mismatch";
785 state->mode = BAD;
786 break;
787 }
788 INITBITS();
789 }
790 if (state->head != Z_NULL) {
791 state->head->hcrc = (int)((state->flags >> 9) & 1);
792 state->head->done = 1;
793 }
794 strm->adler = state->check = crc32(0L, Z_NULL, 0);
795 state->mode = TYPE;
796 break;
797 #endif
798 case DICTID:
799 NEEDBITS(32);
800 strm->adler = state->check = REVERSE(hold);
801 INITBITS();
802 state->mode = DICT;
803 case DICT:
804 if (state->havedict == 0) {
805 RESTORE();
806 return Z_NEED_DICT;
807 }
808 strm->adler = state->check = adler32(0L, Z_NULL, 0);
809 state->mode = TYPE;
810 case TYPE:
811 if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
812 case TYPEDO:
813 if (state->last) {
814 BYTEBITS();
815 state->mode = CHECK;
816 break;
817 }
818 NEEDBITS(3);
819 state->last = BITS(1);
820 DROPBITS(1);
821 switch (BITS(2)) {
822 case 0: /* stored block */
823 Tracev((stderr, "inflate: stored block%s\n",
824 state->last ? " (last)" : ""));
825 state->mode = STORED;
826 break;
827 case 1: /* fixed block */
828 fixedtables(state);
829 Tracev((stderr, "inflate: fixed codes block%s\n",
830 state->last ? " (last)" : ""));
831 state->mode = LEN_; /* decode codes */
832 if (flush == Z_TREES) {
833 DROPBITS(2);
834 goto inf_leave;
835 }
836 break;
837 case 2: /* dynamic block */
838 Tracev((stderr, "inflate: dynamic codes block%s\n",
839 state->last ? " (last)" : ""));
840 state->mode = TABLE;
841 break;
842 case 3:
843 strm->msg = (char *)"invalid block type";
844 state->mode = BAD;
845 }
846 DROPBITS(2);
847 break;
848 case STORED:
849 BYTEBITS(); /* go to byte boundary */
850 NEEDBITS(32);
851 if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
852 strm->msg = (char *)"invalid stored block lengths";
853 state->mode = BAD;
854 break;
855 }
856 state->length = (unsigned)hold & 0xffff;
857 Tracev((stderr, "inflate: stored length %u\n",
858 state->length));
859 INITBITS();
860 state->mode = COPY_;
861 if (flush == Z_TREES) goto inf_leave;
862 case COPY_:
863 state->mode = COPY;
864 case COPY:
865 copy = state->length;
866 if (copy) {
867 if (copy > have) copy = have;
868 if (copy > left) copy = left;
869 if (copy == 0) goto inf_leave;
870 zmemcpy(put, next, copy);
871 have -= copy;
872 next += copy;
873 left -= copy;
874 put += copy;
875 state->length -= copy;
876 break;
877 }
878 Tracev((stderr, "inflate: stored end\n"));
879 state->mode = TYPE;
880 break;
881 case TABLE:
882 NEEDBITS(14);
883 state->nlen = BITS(5) + 257;
884 DROPBITS(5);
885 state->ndist = BITS(5) + 1;
886 DROPBITS(5);
887 state->ncode = BITS(4) + 4;
888 DROPBITS(4);
889 #ifndef PKZIP_BUG_WORKAROUND
890 if (state->nlen > 286 || state->ndist > 30) {
891 strm->msg = (char *)"too many length or distance symbols";
892 state->mode = BAD;
893 break;
894 }
895 #endif
896 Tracev((stderr, "inflate: table sizes ok\n"));
897 state->have = 0;
898 state->mode = LENLENS;
899 case LENLENS:
900 while (state->have < state->ncode) {
901 NEEDBITS(3);
902 state->lens[order[state->have++]] = (unsigned short)BITS(3);
903 DROPBITS(3);
904 }
905 while (state->have < 19)
906 state->lens[order[state->have++]] = 0;
907 state->next = state->codes;
908 state->lencode = (code const FAR *)(state->next);
909 state->lenbits = 7;
910 ret = inflate_table(CODES, state->lens, 19, &(state->next),
911 &(state->lenbits), state->work);
912 if (ret) {
913 strm->msg = (char *)"invalid code lengths set";
914 state->mode = BAD;
915 break;
916 }
917 Tracev((stderr, "inflate: code lengths ok\n"));
918 state->have = 0;
919 state->mode = CODELENS;
920 case CODELENS:
921 while (state->have < state->nlen + state->ndist) {
922 for (;;) {
923 here = state->lencode[BITS(state->lenbits)];
924 if ((unsigned)(here.bits) <= bits) break;
925 PULLBYTE();
926 }
927 if (here.val < 16) {
928 NEEDBITS(here.bits);
929 DROPBITS(here.bits);
930 state->lens[state->have++] = here.val;
931 }
932 else {
933 if (here.val == 16) {
934 NEEDBITS(here.bits + 2);
935 DROPBITS(here.bits);
936 if (state->have == 0) {
937 strm->msg = (char *)"invalid bit length repeat";
938 state->mode = BAD;
939 break;
940 }
941 len = state->lens[state->have - 1];
942 copy = 3 + BITS(2);
943 DROPBITS(2);
944 }
945 else if (here.val == 17) {
946 NEEDBITS(here.bits + 3);
947 DROPBITS(here.bits);
948 len = 0;
949 copy = 3 + BITS(3);
950 DROPBITS(3);
951 }
952 else {
953 NEEDBITS(here.bits + 7);
954 DROPBITS(here.bits);
955 len = 0;
956 copy = 11 + BITS(7);
957 DROPBITS(7);
958 }
959 if (state->have + copy > state->nlen + state->ndist) {
960 strm->msg = (char *)"invalid bit length repeat";
961 state->mode = BAD;
962 break;
963 }
964 while (copy--)
965 state->lens[state->have++] = (unsigned short)len;
966 }
967 }
968
969 /* handle error breaks in while */
970 if (state->mode == BAD) break;
971
972 /* check for end-of-block code (better have one) */
973 if (state->lens[256] == 0) {
974 strm->msg = (char *)"invalid code -- missing end-of-block";
975 state->mode = BAD;
976 break;
977 }
978
979 /* build code tables -- note: do not change the lenbits or distbits
980 values here (9 and 6) without reading the comments in inftrees.h
981 concerning the ENOUGH constants, which depend on those values */
982 state->next = state->codes;
983 state->lencode = (code const FAR *)(state->next);
984 state->lenbits = 9;
985 ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
986 &(state->lenbits), state->work);
987 if (ret) {
988 strm->msg = (char *)"invalid literal/lengths set";
989 state->mode = BAD;
990 break;
991 }
992 state->distcode = (code const FAR *)(state->next);
993 state->distbits = 6;
994 ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
995 &(state->next), &(state->distbits), state->work);
996 if (ret) {
997 strm->msg = (char *)"invalid distances set";
998 state->mode = BAD;
999 break;
1000 }
1001 Tracev((stderr, "inflate: codes ok\n"));
1002 state->mode = LEN_;
1003 if (flush == Z_TREES) goto inf_leave;
1004 case LEN_:
1005 state->mode = LEN;
1006 case LEN:
1007 if (have >= 6 && left >= 258) {
1008 RESTORE();
1009 inflate_fast(strm, out);
1010 LOAD();
1011 if (state->mode == TYPE)
1012 state->back = -1;
1013 break;
1014 }
1015 state->back = 0;
1016 for (;;) {
1017 here = state->lencode[BITS(state->lenbits)];
1018 if ((unsigned)(here.bits) <= bits) break;
1019 PULLBYTE();
1020 }
1021 if (here.op && (here.op & 0xf0) == 0) {
1022 last = here;
1023 for (;;) {
1024 here = state->lencode[last.val +
1025 (BITS(last.bits + last.op) >> last.bits)];
1026 if ((unsigned)(last.bits + here.bits) <= bits) break;
1027 PULLBYTE();
1028 }
1029 DROPBITS(last.bits);
1030 state->back += last.bits;
1031 }
1032 DROPBITS(here.bits);
1033 state->back += here.bits;
1034 state->length = (unsigned)here.val;
1035 if ((int)(here.op) == 0) {
1036 Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1037 "inflate: literal '%c'\n" :
1038 "inflate: literal 0x%02x\n", here.val));
1039 state->mode = LIT;
1040 break;
1041 }
1042 if (here.op & 32) {
1043 Tracevv((stderr, "inflate: end of block\n"));
1044 state->back = -1;
1045 state->mode = TYPE;
1046 break;
1047 }
1048 if (here.op & 64) {
1049 strm->msg = (char *)"invalid literal/length code";
1050 state->mode = BAD;
1051 break;
1052 }
1053 state->extra = (unsigned)(here.op) & 15;
1054 state->mode = LENEXT;
1055 case LENEXT:
1056 if (state->extra) {
1057 NEEDBITS(state->extra);
1058 state->length += BITS(state->extra);
1059 DROPBITS(state->extra);
1060 state->back += state->extra;
1061 }
1062 Tracevv((stderr, "inflate: length %u\n", state->length));
1063 state->was = state->length;
1064 state->mode = DIST;
1065 case DIST:
1066 for (;;) {
1067 here = state->distcode[BITS(state->distbits)];
1068 if ((unsigned)(here.bits) <= bits) break;
1069 PULLBYTE();
1070 }
1071 if ((here.op & 0xf0) == 0) {
1072 last = here;
1073 for (;;) {
1074 here = state->distcode[last.val +
1075 (BITS(last.bits + last.op) >> last.bits)];
1076 if ((unsigned)(last.bits + here.bits) <= bits) break;
1077 PULLBYTE();
1078 }
1079 DROPBITS(last.bits);
1080 state->back += last.bits;
1081 }
1082 DROPBITS(here.bits);
1083 state->back += here.bits;
1084 if (here.op & 64) {
1085 strm->msg = (char *)"invalid distance code";
1086 state->mode = BAD;
1087 break;
1088 }
1089 state->offset = (unsigned)here.val;
1090 state->extra = (unsigned)(here.op) & 15;
1091 state->mode = DISTEXT;
1092 case DISTEXT:
1093 if (state->extra) {
1094 NEEDBITS(state->extra);
1095 state->offset += BITS(state->extra);
1096 DROPBITS(state->extra);
1097 state->back += state->extra;
1098 }
1099 #ifdef INFLATE_STRICT
1100 if (state->offset > state->dmax) {
1101 strm->msg = (char *)"invalid distance too far back";
1102 state->mode = BAD;
1103 break;
1104 }
1105 #endif
1106 Tracevv((stderr, "inflate: distance %u\n", state->offset));
1107 state->mode = MATCH;
1108 case MATCH:
1109 if (left == 0) goto inf_leave;
1110 copy = out - left;
1111 if (state->offset > copy) { /* copy from window */
1112 copy = state->offset - copy;
1113 if (copy > state->whave) {
1114 if (state->sane) {
1115 strm->msg = (char *)"invalid distance too far back";
1116 state->mode = BAD;
1117 break;
1118 }
1119 #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1120 Trace((stderr, "inflate.c too far\n"));
1121 copy -= state->whave;
1122 if (copy > state->length) copy = state->length;
1123 if (copy > left) copy = left;
1124 left -= copy;
1125 state->length -= copy;
1126 do {
1127 *put++ = 0;
1128 } while (--copy);
1129 if (state->length == 0) state->mode = LEN;
1130 break;
1131 #endif
1132 }
1133 if (copy > state->wnext) {
1134 copy -= state->wnext;
1135 from = state->window + (state->wsize - copy);
1136 }
1137 else
1138 from = state->window + (state->wnext - copy);
1139 if (copy > state->length) copy = state->length;
1140 }
1141 else { /* copy from output */
1142 from = put - state->offset;
1143 copy = state->length;
1144 }
1145 if (copy > left) copy = left;
1146 left -= copy;
1147 state->length -= copy;
1148 do {
1149 *put++ = *from++;
1150 } while (--copy);
1151 if (state->length == 0) state->mode = LEN;
1152 break;
1153 case LIT:
1154 if (left == 0) goto inf_leave;
1155 *put++ = (unsigned char)(state->length);
1156 left--;
1157 state->mode = LEN;
1158 break;
1159 case CHECK:
1160 if (state->wrap) {
1161 NEEDBITS(32);
1162 out -= left;
1163 strm->total_out += out;
1164 state->total += out;
1165 if (out)
1166 strm->adler = state->check =
1167 UPDATE(state->check, put - out, out);
1168 out = left;
1169 if ((
1170 #ifdef GUNZIP
1171 state->flags ? hold :
1172 #endif
1173 REVERSE(hold)) != state->check) {
1174 strm->msg = (char *)"incorrect data check";
1175 state->mode = BAD;
1176 break;
1177 }
1178 INITBITS();
1179 Tracev((stderr, "inflate: check matches trailer\n"));
1180 }
1181 #ifdef GUNZIP
1182 state->mode = LENGTH;
1183 case LENGTH:
1184 if (state->wrap && state->flags) {
1185 NEEDBITS(32);
1186 if (hold != (state->total & 0xffffffffUL)) {
1187 strm->msg = (char *)"incorrect length check";
1188 state->mode = BAD;
1189 break;
1190 }
1191 INITBITS();
1192 Tracev((stderr, "inflate: length matches trailer\n"));
1193 }
1194 #endif
1195 state->mode = DONE;
1196 case DONE:
1197 ret = Z_STREAM_END;
1198 goto inf_leave;
1199 case BAD:
1200 ret = Z_DATA_ERROR;
1201 goto inf_leave;
1202 case MEM:
1203 return Z_MEM_ERROR;
1204 case SYNC:
1205 default:
1206 return Z_STREAM_ERROR;
1207 }
1208
1209 /*
1210 Return from inflate(), updating the total counts and the check value.
1211 If there was no progress during the inflate() call, return a buffer
1212 error. Call updatewindow() to create and/or update the window state.
1213 Note: a memory error from inflate() is non-recoverable.
1214 */
1215 inf_leave:
1216 RESTORE();
1217 if (state->wsize || (state->mode < CHECK && out != strm->avail_out))
1218 if (updatewindow(strm, out)) {
1219 state->mode = MEM;
1220 return Z_MEM_ERROR;
1221 }
1222 in -= strm->avail_in;
1223 out -= strm->avail_out;
1224 strm->total_in += in;
1225 strm->total_out += out;
1226 state->total += out;
1227 if (state->wrap && out)
1228 strm->adler = state->check =
1229 UPDATE(state->check, strm->next_out - out, out);
1230 strm->data_type = state->bits + (state->last ? 64 : 0) +
1231 (state->mode == TYPE ? 128 : 0) +
1232 (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1233 if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1234 ret = Z_BUF_ERROR;
1235 return ret;
1236 }
1237
1238 int ZEXPORT inflateEnd(strm)
1239 z_streamp strm;
1240 {
1241 struct inflate_state FAR *state;
1242 if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
1243 return Z_STREAM_ERROR;
1244 state = (struct inflate_state FAR *)strm->state;
1245 if (state->window != Z_NULL) ZFREE(strm, state->window);
1246 ZFREE(strm, strm->state);
1247 strm->state = Z_NULL;
1248 Tracev((stderr, "inflate: end\n"));
1249 return Z_OK;
1250 }
1251
1252 int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
1253 z_streamp strm;
1254 const Bytef *dictionary;
1255 uInt dictLength;
1256 {
1257 struct inflate_state FAR *state;
1258 unsigned long id;
1259
1260 /* check state */
1261 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1262 state = (struct inflate_state FAR *)strm->state;
1263 if (state->wrap != 0 && state->mode != DICT)
1264 return Z_STREAM_ERROR;
1265
1266 /* check for correct dictionary id */
1267 if (state->mode == DICT) {
1268 id = adler32(0L, Z_NULL, 0);
1269 id = adler32(id, dictionary, dictLength);
1270 if (id != state->check)
1271 return Z_DATA_ERROR;
1272 }
1273
1274 /* copy dictionary to window */
1275 if (updatewindow(strm, strm->avail_out)) {
1276 state->mode = MEM;
1277 return Z_MEM_ERROR;
1278 }
1279 if (dictLength > state->wsize) {
1280 zmemcpy(state->window, dictionary + dictLength - state->wsize,
1281 state->wsize);
1282 state->whave = state->wsize;
1283 }
1284 else {
1285 zmemcpy(state->window + state->wsize - dictLength, dictionary,
1286 dictLength);
1287 state->whave = dictLength;
1288 }
1289 state->havedict = 1;
1290 Tracev((stderr, "inflate: dictionary set\n"));
1291 return Z_OK;
1292 }
1293
1294 int ZEXPORT inflateGetHeader(strm, head)
1295 z_streamp strm;
1296 gz_headerp head;
1297 {
1298 struct inflate_state FAR *state;
1299
1300 /* check state */
1301 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1302 state = (struct inflate_state FAR *)strm->state;
1303 if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
1304
1305 /* save header structure */
1306 state->head = head;
1307 head->done = 0;
1308 return Z_OK;
1309 }
1310
1311 /*
1312 Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found
1313 or when out of input. When called, *have is the number of pattern bytes
1314 found in order so far, in 0..3. On return *have is updated to the new
1315 state. If on return *have equals four, then the pattern was found and the
1316 return value is how many bytes were read including the last byte of the
1317 pattern. If *have is less than four, then the pattern has not been found
1318 yet and the return value is len. In the latter case, syncsearch() can be
1319 called again with more data and the *have state. *have is initialized to
1320 zero for the first call.
1321 */
1322 local unsigned syncsearch(have, buf, len)
1323 unsigned FAR *have;
1324 unsigned char FAR *buf;
1325 unsigned len;
1326 {
1327 unsigned got;
1328 unsigned next;
1329
1330 got = *have;
1331 next = 0;
1332 while (next < len && got < 4) {
1333 if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
1334 got++;
1335 else if (buf[next])
1336 got = 0;
1337 else
1338 got = 4 - got;
1339 next++;
1340 }
1341 *have = got;
1342 return next;
1343 }
1344
1345 int ZEXPORT inflateSync(strm)
1346 z_streamp strm;
1347 {
1348 unsigned len; /* number of bytes to look at or looked at */
1349 unsigned long in, out; /* temporary to save total_in and total_out */
1350 unsigned char buf[4]; /* to restore bit buffer to byte string */
1351 struct inflate_state FAR *state;
1352
1353 /* check parameters */
1354 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1355 state = (struct inflate_state FAR *)strm->state;
1356 if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
1357
1358 /* if first time, start search in bit buffer */
1359 if (state->mode != SYNC) {
1360 state->mode = SYNC;
1361 state->hold <<= state->bits & 7;
1362 state->bits -= state->bits & 7;
1363 len = 0;
1364 while (state->bits >= 8) {
1365 buf[len++] = (unsigned char)(state->hold);
1366 state->hold >>= 8;
1367 state->bits -= 8;
1368 }
1369 state->have = 0;
1370 syncsearch(&(state->have), buf, len);
1371 }
1372
1373 /* search available input */
1374 len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
1375 strm->avail_in -= len;
1376 strm->next_in += len;
1377 strm->total_in += len;
1378
1379 /* return no joy or set up to restart inflate() on a new block */
1380 if (state->have != 4) return Z_DATA_ERROR;
1381 in = strm->total_in; out = strm->total_out;
1382 inflateReset(strm);
1383 strm->total_in = in; strm->total_out = out;
1384 state->mode = TYPE;
1385 return Z_OK;
1386 }
1387
1388 /*
1389 Returns true if inflate is currently at the end of a block generated by
1390 Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
1391 implementation to provide an additional safety check. PPP uses
1392 Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
1393 block. When decompressing, PPP checks that at the end of input packet,
1394 inflate is waiting for these length bytes.
1395 */
1396 int ZEXPORT inflateSyncPoint(strm)
1397 z_streamp strm;
1398 {
1399 struct inflate_state FAR *state;
1400
1401 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1402 state = (struct inflate_state FAR *)strm->state;
1403 return state->mode == STORED && state->bits == 0;
1404 }
1405
1406 int ZEXPORT inflateCopy(dest, source)
1407 z_streamp dest;
1408 z_streamp source;
1409 {
1410 struct inflate_state FAR *state;
1411 struct inflate_state FAR *copy;
1412 unsigned char FAR *window;
1413 unsigned wsize;
1414
1415 /* check input */
1416 if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL ||
1417 source->zalloc == (alloc_func)0 || source->zfree == (free_func)0)
1418 return Z_STREAM_ERROR;
1419 state = (struct inflate_state FAR *)source->state;
1420
1421 /* allocate space */
1422 copy = (struct inflate_state FAR *)
1423 ZALLOC(source, 1, sizeof(struct inflate_state));
1424 if (copy == Z_NULL) return Z_MEM_ERROR;
1425 window = Z_NULL;
1426 if (state->window != Z_NULL) {
1427 window = (unsigned char FAR *)
1428 ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
1429 if (window == Z_NULL) {
1430 ZFREE(source, copy);
1431 return Z_MEM_ERROR;
1432 }
1433 }
1434
1435 /* copy state */
1436 zmemcpy(dest, source, sizeof(z_stream));
1437 zmemcpy(copy, state, sizeof(struct inflate_state));
1438 if (state->lencode >= state->codes &&
1439 state->lencode <= state->codes + ENOUGH - 1) {
1440 copy->lencode = copy->codes + (state->lencode - state->codes);
1441 copy->distcode = copy->codes + (state->distcode - state->codes);
1442 }
1443 copy->next = copy->codes + (state->next - state->codes);
1444 if (window != Z_NULL) {
1445 wsize = 1U << state->wbits;
1446 zmemcpy(window, state->window, wsize);
1447 }
1448 copy->window = window;
1449 dest->state = (struct internal_state FAR *)copy;
1450 return Z_OK;
1451 }
1452
1453 int ZEXPORT inflateUndermine(strm, subvert)
1454 z_streamp strm;
1455 int subvert;
1456 {
1457 struct inflate_state FAR *state;
1458
1459 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1460 state = (struct inflate_state FAR *)strm->state;
1461 state->sane = !subvert;
1462 #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1463 return Z_OK;
1464 #else
1465 state->sane = 1;
1466 return Z_DATA_ERROR;
1467 #endif
1468 }
1469
1470 long ZEXPORT inflateMark(strm)
1471 z_streamp strm;
1472 {
1473 struct inflate_state FAR *state;
1474
1475 if (strm == Z_NULL || strm->state == Z_NULL) return -1L << 16;
1476 state = (struct inflate_state FAR *)strm->state;
1477 return ((long)(state->back) << 16) +
1478 (state->mode == COPY ? state->length :
1479 (state->mode == MATCH ? state->was - state->length : 0));
1480 }