1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation. Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25 /* inflate.c -- zlib decompression
26 * Copyright (C) 1995-2010 Mark Adler
27 * For conditions of distribution and use, see copyright notice in zlib.h
28 */
29
30 /*
31 * Change history:
32 *
33 * 1.2.beta0 24 Nov 2002
34 * - First version -- complete rewrite of inflate to simplify code, avoid
35 * creation of window when not needed, minimize use of window when it is
36 * needed, make inffast.c even faster, implement gzip decoding, and to
37 * improve code readability and style over the previous zlib inflate code
38 *
39 * 1.2.beta1 25 Nov 2002
40 * - Use pointers for available input and output checking in inffast.c
41 * - Remove input and output counters in inffast.c
42 * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
43 * - Remove unnecessary second byte pull from length extra in inffast.c
44 * - Unroll direct copy to three copies per loop in inffast.c
45 *
46 * 1.2.beta2 4 Dec 2002
47 * - Change external routine names to reduce potential conflicts
48 * - Correct filename to inffixed.h for fixed tables in inflate.c
49 * - Make hbuf[] unsigned char to match parameter type in inflate.c
50 * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
51 * to avoid negation problem on Alphas (64 bit) in inflate.c
52 *
53 * 1.2.beta3 22 Dec 2002
54 * - Add comments on state->bits assertion in inffast.c
55 * - Add comments on op field in inftrees.h
56 * - Fix bug in reuse of allocated window after inflateReset()
57 * - Remove bit fields--back to byte structure for speed
58 * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
59 * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
60 * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
61 * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
62 * - Use local copies of stream next and avail values, as well as local bit
63 * buffer and bit count in inflate()--for speed when inflate_fast() not used
64 *
65 * 1.2.beta4 1 Jan 2003
66 * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
67 * - Move a comment on output buffer sizes from inffast.c to inflate.c
68 * - Add comments in inffast.c to introduce the inflate_fast() routine
69 * - Rearrange window copies in inflate_fast() for speed and simplification
70 * - Unroll last copy for window match in inflate_fast()
71 * - Use local copies of window variables in inflate_fast() for speed
72 * - Pull out common wnext == 0 case for speed in inflate_fast()
73 * - Make op and len in inflate_fast() unsigned for consistency
74 * - Add FAR to lcode and dcode declarations in inflate_fast()
75 * - Simplified bad distance check in inflate_fast()
76 * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
77 * source file infback.c to provide a call-back interface to inflate for
78 * programs like gzip and unzip -- uses window as output buffer to avoid
79 * window copying
80 *
81 * 1.2.beta5 1 Jan 2003
82 * - Improved inflateBack() interface to allow the caller to provide initial
83 * input in strm.
84 * - Fixed stored blocks bug in inflateBack()
85 *
86 * 1.2.beta6 4 Jan 2003
87 * - Added comments in inffast.c on effectiveness of POSTINC
88 * - Typecasting all around to reduce compiler warnings
89 * - Changed loops from while (1) or do {} while (1) to for (;;), again to
90 * make compilers happy
91 * - Changed type of window in inflateBackInit() to unsigned char *
92 *
93 * 1.2.beta7 27 Jan 2003
94 * - Changed many types to unsigned or unsigned short to avoid warnings
95 * - Added inflateCopy() function
96 *
97 * 1.2.0 9 Mar 2003
98 * - Changed inflateBack() interface to provide separate opaque descriptors
99 * for the in() and out() functions
100 * - Changed inflateBack() argument and in_func typedef to swap the length
101 * and buffer address return values for the input function
102 * - Check next_in and next_out for Z_NULL on entry to inflate()
103 *
104 * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
105 */
106
107 #include "zutil.h"
108 #include "inftrees.h"
109 #include "inflate.h"
110 #include "inffast.h"
111
112 #ifdef MAKEFIXED
113 # ifndef BUILDFIXED
114 # define BUILDFIXED
115 # endif
116 #endif
117
118 /* function prototypes */
119 local void fixedtables OF((struct inflate_state FAR *state));
120 local int updatewindow OF((z_streamp strm, unsigned out));
121 #ifdef BUILDFIXED
122 void makefixed OF((void));
123 #endif
124 local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf,
125 unsigned len));
126
127 int ZEXPORT inflateReset(strm)
128 z_streamp strm;
129 {
130 struct inflate_state FAR *state;
131
132 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
133 state = (struct inflate_state FAR *)strm->state;
134 strm->total_in = strm->total_out = state->total = 0;
135 strm->msg = Z_NULL;
136 strm->adler = 1; /* to support ill-conceived Java test suite */
137 state->mode = HEAD;
138 state->last = 0;
139 state->havedict = 0;
140 state->dmax = 32768U;
141 state->head = Z_NULL;
142 state->wsize = 0;
143 state->whave = 0;
144 state->wnext = 0;
145 state->hold = 0;
146 state->bits = 0;
147 state->lencode = state->distcode = state->next = state->codes;
148 state->sane = 1;
149 state->back = -1;
150 Tracev((stderr, "inflate: reset\n"));
151 return Z_OK;
152 }
153
154 int ZEXPORT inflateReset2(strm, windowBits)
155 z_streamp strm;
156 int windowBits;
157 {
158 int wrap;
159 struct inflate_state FAR *state;
160
161 /* get the state */
162 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
163 state = (struct inflate_state FAR *)strm->state;
164
165 /* extract wrap request from windowBits parameter */
166 if (windowBits < 0) {
167 wrap = 0;
168 windowBits = -windowBits;
169 }
170 else {
171 wrap = (windowBits >> 4) + 1;
172 #ifdef GUNZIP
173 if (windowBits < 48)
174 windowBits &= 15;
175 #endif
176 }
177
178 /* set number of window bits, free window if different */
179 if (windowBits && (windowBits < 8 || windowBits > 15))
180 return Z_STREAM_ERROR;
181 if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
182 ZFREE(strm, state->window);
183 state->window = Z_NULL;
184 }
185
186 /* update state and reset the rest of it */
187 state->wrap = wrap;
188 state->wbits = (unsigned)windowBits;
189 return inflateReset(strm);
190 }
191
192 int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
193 z_streamp strm;
194 int windowBits;
195 const char *version;
196 int stream_size;
197 {
198 int ret;
199 struct inflate_state FAR *state;
200
201 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
202 stream_size != (int)(sizeof(z_stream)))
203 return Z_VERSION_ERROR;
204 if (strm == Z_NULL) return Z_STREAM_ERROR;
205 strm->msg = Z_NULL; /* in case we return an error */
206 if (strm->zalloc == (alloc_func)0) {
207 strm->zalloc = zcalloc;
208 strm->opaque = (voidpf)0;
209 }
210 if (strm->zfree == (free_func)0) strm->zfree = zcfree;
211 state = (struct inflate_state FAR *)
212 ZALLOC(strm, 1, sizeof(struct inflate_state));
213 if (state == Z_NULL) return Z_MEM_ERROR;
214 Tracev((stderr, "inflate: allocated\n"));
215 strm->state = (struct internal_state FAR *)state;
216 state->window = Z_NULL;
217 ret = inflateReset2(strm, windowBits);
218 if (ret != Z_OK) {
219 ZFREE(strm, state);
220 strm->state = Z_NULL;
221 }
222 return ret;
223 }
224
225 int ZEXPORT inflateInit_(strm, version, stream_size)
226 z_streamp strm;
227 const char *version;
228 int stream_size;
229 {
230 return inflateInit2_(strm, DEF_WBITS, version, stream_size);
231 }
232
233 int ZEXPORT inflatePrime(strm, bits, value)
234 z_streamp strm;
235 int bits;
236 int value;
237 {
238 struct inflate_state FAR *state;
239
240 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
241 state = (struct inflate_state FAR *)strm->state;
242 if (bits < 0) {
243 state->hold = 0;
244 state->bits = 0;
245 return Z_OK;
246 }
247 if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
248 value &= (1L << bits) - 1;
249 state->hold += value << state->bits;
250 state->bits += bits;
251 return Z_OK;
252 }
253
254 /*
255 Return state with length and distance decoding tables and index sizes set to
256 fixed code decoding. Normally this returns fixed tables from inffixed.h.
257 If BUILDFIXED is defined, then instead this routine builds the tables the
258 first time it's called, and returns those tables the first time and
259 thereafter. This reduces the size of the code by about 2K bytes, in
260 exchange for a little execution time. However, BUILDFIXED should not be
261 used for threaded applications, since the rewriting of the tables and virgin
262 may not be thread-safe.
263 */
264 local void fixedtables(state)
265 struct inflate_state FAR *state;
266 {
267 #ifdef BUILDFIXED
268 static int virgin = 1;
269 static code *lenfix, *distfix;
270 static code fixed[544];
271
272 /* build fixed huffman tables if first call (may not be thread safe) */
273 if (virgin) {
274 unsigned sym, bits;
275 static code *next;
276
277 /* literal/length table */
278 sym = 0;
279 while (sym < 144) state->lens[sym++] = 8;
280 while (sym < 256) state->lens[sym++] = 9;
281 while (sym < 280) state->lens[sym++] = 7;
282 while (sym < 288) state->lens[sym++] = 8;
283 next = fixed;
284 lenfix = next;
285 bits = 9;
286 inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
287
288 /* distance table */
289 sym = 0;
290 while (sym < 32) state->lens[sym++] = 5;
291 distfix = next;
292 bits = 5;
293 inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
294
295 /* do this just once */
296 virgin = 0;
297 }
298 #else /* !BUILDFIXED */
299 # include "inffixed.h"
300 #endif /* BUILDFIXED */
301 state->lencode = lenfix;
302 state->lenbits = 9;
303 state->distcode = distfix;
304 state->distbits = 5;
305 }
306
307 #ifdef MAKEFIXED
308 #include <stdio.h>
309
310 /*
311 Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also
312 defines BUILDFIXED, so the tables are built on the fly. makefixed() writes
313 those tables to stdout, which would be piped to inffixed.h. A small program
314 can simply call makefixed to do this:
315
316 void makefixed(void);
317
318 int main(void)
319 {
320 makefixed();
321 return 0;
322 }
323
324 Then that can be linked with zlib built with MAKEFIXED defined and run:
325
326 a.out > inffixed.h
327 */
328 void makefixed()
329 {
330 unsigned low, size;
331 struct inflate_state state;
332
333 fixedtables(&state);
334 puts(" /* inffixed.h -- table for decoding fixed codes");
335 puts(" * Generated automatically by makefixed().");
336 puts(" */");
337 puts("");
338 puts(" /* WARNING: this file should *not* be used by applications.");
339 puts(" It is part of the implementation of this library and is");
340 puts(" subject to change. Applications should only use zlib.h.");
341 puts(" */");
342 puts("");
343 size = 1U << 9;
344 printf(" static const code lenfix[%u] = {", size);
345 low = 0;
346 for (;;) {
347 if ((low % 7) == 0) printf("\n ");
348 printf("{%u,%u,%d}", state.lencode[low].op, state.lencode[low].bits,
349 state.lencode[low].val);
350 if (++low == size) break;
351 putchar(',');
352 }
353 puts("\n };");
354 size = 1U << 5;
355 printf("\n static const code distfix[%u] = {", size);
356 low = 0;
357 for (;;) {
358 if ((low % 6) == 0) printf("\n ");
359 printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
360 state.distcode[low].val);
361 if (++low == size) break;
362 putchar(',');
363 }
364 puts("\n };");
365 }
366 #endif /* MAKEFIXED */
367
368 /*
369 Update the window with the last wsize (normally 32K) bytes written before
370 returning. If window does not exist yet, create it. This is only called
371 when a window is already in use, or when output has been written during this
372 inflate call, but the end of the deflate stream has not been reached yet.
373 It is also called to create a window for dictionary data when a dictionary
374 is loaded.
375
376 Providing output buffers larger than 32K to inflate() should provide a speed
377 advantage, since only the last 32K of output is copied to the sliding window
378 upon return from inflate(), and since all distances after the first 32K of
379 output will fall in the output data, making match copies simpler and faster.
380 The advantage may be dependent on the size of the processor's data caches.
381 */
382 local int updatewindow(strm, out)
383 z_streamp strm;
384 unsigned out;
385 {
386 struct inflate_state FAR *state;
387 unsigned copy, dist;
388
389 state = (struct inflate_state FAR *)strm->state;
390
391 /* if it hasn't been done already, allocate space for the window */
392 if (state->window == Z_NULL) {
393 state->window = (unsigned char FAR *)
394 ZALLOC(strm, 1U << state->wbits,
395 sizeof(unsigned char));
396 if (state->window == Z_NULL) return 1;
397 }
398
399 /* if window not in use yet, initialize */
400 if (state->wsize == 0) {
401 state->wsize = 1U << state->wbits;
402 state->wnext = 0;
403 state->whave = 0;
404 }
405
406 /* copy state->wsize or less output bytes into the circular window */
407 copy = out - strm->avail_out;
408 if (copy >= state->wsize) {
409 zmemcpy(state->window, strm->next_out - state->wsize, state->wsize);
410 state->wnext = 0;
411 state->whave = state->wsize;
412 }
413 else {
414 dist = state->wsize - state->wnext;
415 if (dist > copy) dist = copy;
416 zmemcpy(state->window + state->wnext, strm->next_out - copy, dist);
417 copy -= dist;
418 if (copy) {
419 zmemcpy(state->window, strm->next_out - copy, copy);
420 state->wnext = copy;
421 state->whave = state->wsize;
422 }
423 else {
424 state->wnext += dist;
425 if (state->wnext == state->wsize) state->wnext = 0;
426 if (state->whave < state->wsize) state->whave += dist;
427 }
428 }
429 return 0;
430 }
431
432 /* Macros for inflate(): */
433
434 /* check function to use adler32() for zlib or crc32() for gzip */
435 #ifdef GUNZIP
436 # define UPDATE(check, buf, len) \
437 (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
438 #else
439 # define UPDATE(check, buf, len) adler32(check, buf, len)
440 #endif
441
442 /* check macros for header crc */
443 #ifdef GUNZIP
444 # define CRC2(check, word) \
445 do { \
446 hbuf[0] = (unsigned char)(word); \
447 hbuf[1] = (unsigned char)((word) >> 8); \
448 check = crc32(check, hbuf, 2); \
449 } while (0)
450
451 # define CRC4(check, word) \
452 do { \
453 hbuf[0] = (unsigned char)(word); \
454 hbuf[1] = (unsigned char)((word) >> 8); \
455 hbuf[2] = (unsigned char)((word) >> 16); \
456 hbuf[3] = (unsigned char)((word) >> 24); \
457 check = crc32(check, hbuf, 4); \
458 } while (0)
459 #endif
460
461 /* Load registers with state in inflate() for speed */
462 #define LOAD() \
463 do { \
464 put = strm->next_out; \
465 left = strm->avail_out; \
466 next = strm->next_in; \
467 have = strm->avail_in; \
468 hold = state->hold; \
469 bits = state->bits; \
470 } while (0)
471
472 /* Restore state from registers in inflate() */
473 #define RESTORE() \
474 do { \
475 strm->next_out = put; \
476 strm->avail_out = left; \
477 strm->next_in = next; \
478 strm->avail_in = have; \
479 state->hold = hold; \
480 state->bits = bits; \
481 } while (0)
482
483 /* Clear the input bit accumulator */
484 #define INITBITS() \
485 do { \
486 hold = 0; \
487 bits = 0; \
488 } while (0)
489
490 /* Get a byte of input into the bit accumulator, or return from inflate()
491 if there is no input available. */
492 #define PULLBYTE() \
493 do { \
494 if (have == 0) goto inf_leave; \
495 have--; \
496 hold += (unsigned long)(*next++) << bits; \
497 bits += 8; \
498 } while (0)
499
500 /* Assure that there are at least n bits in the bit accumulator. If there is
501 not enough available input to do that, then return from inflate(). */
502 #define NEEDBITS(n) \
503 do { \
504 while (bits < (unsigned)(n)) \
505 PULLBYTE(); \
506 } while (0)
507
508 /* Return the low n bits of the bit accumulator (n < 16) */
509 #define BITS(n) \
510 ((unsigned)hold & ((1U << (n)) - 1))
511
512 /* Remove n bits from the bit accumulator */
513 #define DROPBITS(n) \
514 do { \
515 hold >>= (n); \
516 bits -= (unsigned)(n); \
517 } while (0)
518
519 /* Remove zero to seven bits as needed to go to a byte boundary */
520 #define BYTEBITS() \
521 do { \
522 hold >>= bits & 7; \
523 bits -= bits & 7; \
524 } while (0)
525
526 /* Reverse the bytes in a 32-bit value */
527 #define REVERSE(q) \
528 ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
529 (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
530
531 /*
532 inflate() uses a state machine to process as much input data and generate as
533 much output data as possible before returning. The state machine is
534 structured roughly as follows:
535
536 for (;;) switch (state) {
537 ...
538 case STATEn:
539 if (not enough input data or output space to make progress)
540 return;
541 ... make progress ...
542 state = STATEm;
543 break;
544 ...
545 }
546
547 so when inflate() is called again, the same case is attempted again, and
548 if the appropriate resources are provided, the machine proceeds to the
549 next state. The NEEDBITS() macro is usually the way the state evaluates
550 whether it can proceed or should return. NEEDBITS() does the return if
551 the requested bits are not available. The typical use of the BITS macros
552 is:
553
554 NEEDBITS(n);
555 ... do something with BITS(n) ...
556 DROPBITS(n);
557
558 where NEEDBITS(n) either returns from inflate() if there isn't enough
559 input left to load n bits into the accumulator, or it continues. BITS(n)
560 gives the low n bits in the accumulator. When done, DROPBITS(n) drops
561 the low n bits off the accumulator. INITBITS() clears the accumulator
562 and sets the number of available bits to zero. BYTEBITS() discards just
563 enough bits to put the accumulator on a byte boundary. After BYTEBITS()
564 and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
565
566 NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
567 if there is no input available. The decoding of variable length codes uses
568 PULLBYTE() directly in order to pull just enough bytes to decode the next
569 code, and no more.
570
571 Some states loop until they get enough input, making sure that enough
572 state information is maintained to continue the loop where it left off
573 if NEEDBITS() returns in the loop. For example, want, need, and keep
574 would all have to actually be part of the saved state in case NEEDBITS()
575 returns:
576
577 case STATEw:
578 while (want < need) {
579 NEEDBITS(n);
580 keep[want++] = BITS(n);
581 DROPBITS(n);
582 }
583 state = STATEx;
584 case STATEx:
585
586 As shown above, if the next state is also the next case, then the break
587 is omitted.
588
589 A state may also return if there is not enough output space available to
590 complete that state. Those states are copying stored data, writing a
591 literal byte, and copying a matching string.
592
593 When returning, a "goto inf_leave" is used to update the total counters,
594 update the check value, and determine whether any progress has been made
595 during that inflate() call in order to return the proper return code.
596 Progress is defined as a change in either strm->avail_in or strm->avail_out.
597 When there is a window, goto inf_leave will update the window with the last
598 output written. If a goto inf_leave occurs in the middle of decompression
599 and there is no window currently, goto inf_leave will create one and copy
600 output to the window for the next call of inflate().
601
602 In this implementation, the flush parameter of inflate() only affects the
603 return code (per zlib.h). inflate() always writes as much as possible to
604 strm->next_out, given the space available and the provided input--the effect
605 documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
606 the allocation of and copying into a sliding window until necessary, which
607 provides the effect documented in zlib.h for Z_FINISH when the entire input
608 stream available. So the only thing the flush parameter actually does is:
609 when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
610 will return Z_BUF_ERROR if it has not reached the end of the stream.
611 */
612
613 int ZEXPORT inflate(strm, flush)
614 z_streamp strm;
615 int flush;
616 {
617 struct inflate_state FAR *state;
618 unsigned char FAR *next; /* next input */
619 unsigned char FAR *put; /* next output */
620 unsigned have, left; /* available input and output */
621 unsigned long hold; /* bit buffer */
622 unsigned bits; /* bits in bit buffer */
623 unsigned in, out; /* save starting available input and output */
624 unsigned copy; /* number of stored or match bytes to copy */
625 unsigned char FAR *from; /* where to copy match bytes from */
626 code here; /* current decoding table entry */
627 code last; /* parent table entry */
628 unsigned len; /* length to copy for repeats, bits to drop */
629 int ret; /* return code */
630 #ifdef GUNZIP
631 unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
632 #endif
633 static const unsigned short order[19] = /* permutation of code lengths */
634 {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
635
636 if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL ||
637 (strm->next_in == Z_NULL && strm->avail_in != 0))
638 return Z_STREAM_ERROR;
639
640 state = (struct inflate_state FAR *)strm->state;
641 if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
642 LOAD();
643 in = have;
644 out = left;
645 ret = Z_OK;
646 for (;;)
647 switch (state->mode) {
648 case HEAD:
649 if (state->wrap == 0) {
650 state->mode = TYPEDO;
651 break;
652 }
653 NEEDBITS(16);
654 #ifdef GUNZIP
655 if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
656 state->check = crc32(0L, Z_NULL, 0);
657 CRC2(state->check, hold);
658 INITBITS();
659 state->mode = FLAGS;
660 break;
661 }
662 state->flags = 0; /* expect zlib header */
663 if (state->head != Z_NULL)
664 state->head->done = -1;
665 if (!(state->wrap & 1) || /* check if zlib header allowed */
666 #else
667 if (
668 #endif
669 ((BITS(8) << 8) + (hold >> 8)) % 31) {
670 strm->msg = (char *)"incorrect header check";
671 state->mode = BAD;
672 break;
673 }
674 if (BITS(4) != Z_DEFLATED) {
675 strm->msg = (char *)"unknown compression method";
676 state->mode = BAD;
677 break;
678 }
679 DROPBITS(4);
680 len = BITS(4) + 8;
681 if (state->wbits == 0)
682 state->wbits = len;
683 else if (len > state->wbits) {
684 strm->msg = (char *)"invalid window size";
685 state->mode = BAD;
686 break;
687 }
688 state->dmax = 1U << len;
689 Tracev((stderr, "inflate: zlib header ok\n"));
690 strm->adler = state->check = adler32(0L, Z_NULL, 0);
691 state->mode = hold & 0x200 ? DICTID : TYPE;
692 INITBITS();
693 break;
694 #ifdef GUNZIP
695 case FLAGS:
696 NEEDBITS(16);
697 state->flags = (int)(hold);
698 if ((state->flags & 0xff) != Z_DEFLATED) {
699 strm->msg = (char *)"unknown compression method";
700 state->mode = BAD;
701 break;
702 }
703 if (state->flags & 0xe000) {
704 strm->msg = (char *)"unknown header flags set";
705 state->mode = BAD;
706 break;
707 }
708 if (state->head != Z_NULL)
709 state->head->text = (int)((hold >> 8) & 1);
710 if (state->flags & 0x0200) CRC2(state->check, hold);
711 INITBITS();
712 state->mode = TIME;
713 case TIME:
714 NEEDBITS(32);
715 if (state->head != Z_NULL)
716 state->head->time = hold;
717 if (state->flags & 0x0200) CRC4(state->check, hold);
718 INITBITS();
719 state->mode = OS;
720 case OS:
721 NEEDBITS(16);
722 if (state->head != Z_NULL) {
723 state->head->xflags = (int)(hold & 0xff);
724 state->head->os = (int)(hold >> 8);
725 }
726 if (state->flags & 0x0200) CRC2(state->check, hold);
727 INITBITS();
728 state->mode = EXLEN;
729 case EXLEN:
730 if (state->flags & 0x0400) {
731 NEEDBITS(16);
732 state->length = (unsigned)(hold);
733 if (state->head != Z_NULL)
734 state->head->extra_len = (unsigned)hold;
735 if (state->flags & 0x0200) CRC2(state->check, hold);
736 INITBITS();
737 }
738 else if (state->head != Z_NULL)
739 state->head->extra = Z_NULL;
740 state->mode = EXTRA;
741 case EXTRA:
742 if (state->flags & 0x0400) {
743 copy = state->length;
744 if (copy > have) copy = have;
745 if (copy) {
746 if (state->head != Z_NULL &&
747 state->head->extra != Z_NULL) {
748 len = state->head->extra_len - state->length;
749 zmemcpy(state->head->extra + len, next,
750 len + copy > state->head->extra_max ?
751 state->head->extra_max - len : copy);
752 }
753 if (state->flags & 0x0200)
754 state->check = crc32(state->check, next, copy);
755 have -= copy;
756 next += copy;
757 state->length -= copy;
758 }
759 if (state->length) goto inf_leave;
760 }
761 state->length = 0;
762 state->mode = NAME;
763 case NAME:
764 if (state->flags & 0x0800) {
765 if (have == 0) goto inf_leave;
766 copy = 0;
767 do {
768 len = (unsigned)(next[copy++]);
769 if (state->head != Z_NULL &&
770 state->head->name != Z_NULL &&
771 state->length < state->head->name_max)
772 state->head->name[state->length++] = len;
773 } while (len && copy < have);
774 if (state->flags & 0x0200)
775 state->check = crc32(state->check, next, copy);
776 have -= copy;
777 next += copy;
778 if (len) goto inf_leave;
779 }
780 else if (state->head != Z_NULL)
781 state->head->name = Z_NULL;
782 state->length = 0;
783 state->mode = COMMENT;
784 case COMMENT:
785 if (state->flags & 0x1000) {
786 if (have == 0) goto inf_leave;
787 copy = 0;
788 do {
789 len = (unsigned)(next[copy++]);
790 if (state->head != Z_NULL &&
791 state->head->comment != Z_NULL &&
792 state->length < state->head->comm_max)
793 state->head->comment[state->length++] = len;
794 } while (len && copy < have);
795 if (state->flags & 0x0200)
796 state->check = crc32(state->check, next, copy);
797 have -= copy;
798 next += copy;
799 if (len) goto inf_leave;
800 }
801 else if (state->head != Z_NULL)
802 state->head->comment = Z_NULL;
803 state->mode = HCRC;
804 case HCRC:
805 if (state->flags & 0x0200) {
806 NEEDBITS(16);
807 if (hold != (state->check & 0xffff)) {
808 strm->msg = (char *)"header crc mismatch";
809 state->mode = BAD;
810 break;
811 }
812 INITBITS();
813 }
814 if (state->head != Z_NULL) {
815 state->head->hcrc = (int)((state->flags >> 9) & 1);
816 state->head->done = 1;
817 }
818 strm->adler = state->check = crc32(0L, Z_NULL, 0);
819 state->mode = TYPE;
820 break;
821 #endif
822 case DICTID:
823 NEEDBITS(32);
824 strm->adler = state->check = REVERSE(hold);
825 INITBITS();
826 state->mode = DICT;
827 case DICT:
828 if (state->havedict == 0) {
829 RESTORE();
830 return Z_NEED_DICT;
831 }
832 strm->adler = state->check = adler32(0L, Z_NULL, 0);
833 state->mode = TYPE;
834 case TYPE:
835 if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
836 case TYPEDO:
837 if (state->last) {
838 BYTEBITS();
839 state->mode = CHECK;
840 break;
841 }
842 NEEDBITS(3);
843 state->last = BITS(1);
844 DROPBITS(1);
845 switch (BITS(2)) {
846 case 0: /* stored block */
847 Tracev((stderr, "inflate: stored block%s\n",
848 state->last ? " (last)" : ""));
849 state->mode = STORED;
850 break;
851 case 1: /* fixed block */
852 fixedtables(state);
853 Tracev((stderr, "inflate: fixed codes block%s\n",
854 state->last ? " (last)" : ""));
855 state->mode = LEN_; /* decode codes */
856 if (flush == Z_TREES) {
857 DROPBITS(2);
858 goto inf_leave;
859 }
860 break;
861 case 2: /* dynamic block */
862 Tracev((stderr, "inflate: dynamic codes block%s\n",
863 state->last ? " (last)" : ""));
864 state->mode = TABLE;
865 break;
866 case 3:
867 strm->msg = (char *)"invalid block type";
868 state->mode = BAD;
869 }
870 DROPBITS(2);
871 break;
872 case STORED:
873 BYTEBITS(); /* go to byte boundary */
874 NEEDBITS(32);
875 if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
876 strm->msg = (char *)"invalid stored block lengths";
877 state->mode = BAD;
878 break;
879 }
880 state->length = (unsigned)hold & 0xffff;
881 Tracev((stderr, "inflate: stored length %u\n",
882 state->length));
883 INITBITS();
884 state->mode = COPY_;
885 if (flush == Z_TREES) goto inf_leave;
886 case COPY_:
887 state->mode = COPY;
888 case COPY:
889 copy = state->length;
890 if (copy) {
891 if (copy > have) copy = have;
892 if (copy > left) copy = left;
893 if (copy == 0) goto inf_leave;
894 zmemcpy(put, next, copy);
895 have -= copy;
896 next += copy;
897 left -= copy;
898 put += copy;
899 state->length -= copy;
900 break;
901 }
902 Tracev((stderr, "inflate: stored end\n"));
903 state->mode = TYPE;
904 break;
905 case TABLE:
906 NEEDBITS(14);
907 state->nlen = BITS(5) + 257;
908 DROPBITS(5);
909 state->ndist = BITS(5) + 1;
910 DROPBITS(5);
911 state->ncode = BITS(4) + 4;
912 DROPBITS(4);
913 #ifndef PKZIP_BUG_WORKAROUND
914 if (state->nlen > 286 || state->ndist > 30) {
915 strm->msg = (char *)"too many length or distance symbols";
916 state->mode = BAD;
917 break;
918 }
919 #endif
920 Tracev((stderr, "inflate: table sizes ok\n"));
921 state->have = 0;
922 state->mode = LENLENS;
923 case LENLENS:
924 while (state->have < state->ncode) {
925 NEEDBITS(3);
926 state->lens[order[state->have++]] = (unsigned short)BITS(3);
927 DROPBITS(3);
928 }
929 while (state->have < 19)
930 state->lens[order[state->have++]] = 0;
931 state->next = state->codes;
932 state->lencode = (code const FAR *)(state->next);
933 state->lenbits = 7;
934 ret = inflate_table(CODES, state->lens, 19, &(state->next),
935 &(state->lenbits), state->work);
936 if (ret) {
937 strm->msg = (char *)"invalid code lengths set";
938 state->mode = BAD;
939 break;
940 }
941 Tracev((stderr, "inflate: code lengths ok\n"));
942 state->have = 0;
943 state->mode = CODELENS;
944 case CODELENS:
945 while (state->have < state->nlen + state->ndist) {
946 for (;;) {
947 here = state->lencode[BITS(state->lenbits)];
948 if ((unsigned)(here.bits) <= bits) break;
949 PULLBYTE();
950 }
951 if (here.val < 16) {
952 NEEDBITS(here.bits);
953 DROPBITS(here.bits);
954 state->lens[state->have++] = here.val;
955 }
956 else {
957 if (here.val == 16) {
958 NEEDBITS(here.bits + 2);
959 DROPBITS(here.bits);
960 if (state->have == 0) {
961 strm->msg = (char *)"invalid bit length repeat";
962 state->mode = BAD;
963 break;
964 }
965 len = state->lens[state->have - 1];
966 copy = 3 + BITS(2);
967 DROPBITS(2);
968 }
969 else if (here.val == 17) {
970 NEEDBITS(here.bits + 3);
971 DROPBITS(here.bits);
972 len = 0;
973 copy = 3 + BITS(3);
974 DROPBITS(3);
975 }
976 else {
977 NEEDBITS(here.bits + 7);
978 DROPBITS(here.bits);
979 len = 0;
980 copy = 11 + BITS(7);
981 DROPBITS(7);
982 }
983 if (state->have + copy > state->nlen + state->ndist) {
984 strm->msg = (char *)"invalid bit length repeat";
985 state->mode = BAD;
986 break;
987 }
988 while (copy--)
989 state->lens[state->have++] = (unsigned short)len;
990 }
991 }
992
993 /* handle error breaks in while */
994 if (state->mode == BAD) break;
995
996 /* check for end-of-block code (better have one) */
997 if (state->lens[256] == 0) {
998 strm->msg = (char *)"invalid code -- missing end-of-block";
999 state->mode = BAD;
1000 break;
1001 }
1002
1003 /* build code tables -- note: do not change the lenbits or distbits
1004 values here (9 and 6) without reading the comments in inftrees.h
1005 concerning the ENOUGH constants, which depend on those values */
1006 state->next = state->codes;
1007 state->lencode = (code const FAR *)(state->next);
1008 state->lenbits = 9;
1009 ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1010 &(state->lenbits), state->work);
1011 if (ret) {
1012 strm->msg = (char *)"invalid literal/lengths set";
1013 state->mode = BAD;
1014 break;
1015 }
1016 state->distcode = (code const FAR *)(state->next);
1017 state->distbits = 6;
1018 ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1019 &(state->next), &(state->distbits), state->work);
1020 if (ret) {
1021 strm->msg = (char *)"invalid distances set";
1022 state->mode = BAD;
1023 break;
1024 }
1025 Tracev((stderr, "inflate: codes ok\n"));
1026 state->mode = LEN_;
1027 if (flush == Z_TREES) goto inf_leave;
1028 case LEN_:
1029 state->mode = LEN;
1030 case LEN:
1031 if (have >= 6 && left >= 258) {
1032 RESTORE();
1033 inflate_fast(strm, out);
1034 LOAD();
1035 if (state->mode == TYPE)
1036 state->back = -1;
1037 break;
1038 }
1039 state->back = 0;
1040 for (;;) {
1041 here = state->lencode[BITS(state->lenbits)];
1042 if ((unsigned)(here.bits) <= bits) break;
1043 PULLBYTE();
1044 }
1045 if (here.op && (here.op & 0xf0) == 0) {
1046 last = here;
1047 for (;;) {
1048 here = state->lencode[last.val +
1049 (BITS(last.bits + last.op) >> last.bits)];
1050 if ((unsigned)(last.bits + here.bits) <= bits) break;
1051 PULLBYTE();
1052 }
1053 DROPBITS(last.bits);
1054 state->back += last.bits;
1055 }
1056 DROPBITS(here.bits);
1057 state->back += here.bits;
1058 state->length = (unsigned)here.val;
1059 if ((int)(here.op) == 0) {
1060 Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1061 "inflate: literal '%c'\n" :
1062 "inflate: literal 0x%02x\n", here.val));
1063 state->mode = LIT;
1064 break;
1065 }
1066 if (here.op & 32) {
1067 Tracevv((stderr, "inflate: end of block\n"));
1068 state->back = -1;
1069 state->mode = TYPE;
1070 break;
1071 }
1072 if (here.op & 64) {
1073 strm->msg = (char *)"invalid literal/length code";
1074 state->mode = BAD;
1075 break;
1076 }
1077 state->extra = (unsigned)(here.op) & 15;
1078 state->mode = LENEXT;
1079 case LENEXT:
1080 if (state->extra) {
1081 NEEDBITS(state->extra);
1082 state->length += BITS(state->extra);
1083 DROPBITS(state->extra);
1084 state->back += state->extra;
1085 }
1086 Tracevv((stderr, "inflate: length %u\n", state->length));
1087 state->was = state->length;
1088 state->mode = DIST;
1089 case DIST:
1090 for (;;) {
1091 here = state->distcode[BITS(state->distbits)];
1092 if ((unsigned)(here.bits) <= bits) break;
1093 PULLBYTE();
1094 }
1095 if ((here.op & 0xf0) == 0) {
1096 last = here;
1097 for (;;) {
1098 here = state->distcode[last.val +
1099 (BITS(last.bits + last.op) >> last.bits)];
1100 if ((unsigned)(last.bits + here.bits) <= bits) break;
1101 PULLBYTE();
1102 }
1103 DROPBITS(last.bits);
1104 state->back += last.bits;
1105 }
1106 DROPBITS(here.bits);
1107 state->back += here.bits;
1108 if (here.op & 64) {
1109 strm->msg = (char *)"invalid distance code";
1110 state->mode = BAD;
1111 break;
1112 }
1113 state->offset = (unsigned)here.val;
1114 state->extra = (unsigned)(here.op) & 15;
1115 state->mode = DISTEXT;
1116 case DISTEXT:
1117 if (state->extra) {
1118 NEEDBITS(state->extra);
1119 state->offset += BITS(state->extra);
1120 DROPBITS(state->extra);
1121 state->back += state->extra;
1122 }
1123 #ifdef INFLATE_STRICT
1124 if (state->offset > state->dmax) {
1125 strm->msg = (char *)"invalid distance too far back";
1126 state->mode = BAD;
1127 break;
1128 }
1129 #endif
1130 Tracevv((stderr, "inflate: distance %u\n", state->offset));
1131 state->mode = MATCH;
1132 case MATCH:
1133 if (left == 0) goto inf_leave;
1134 copy = out - left;
1135 if (state->offset > copy) { /* copy from window */
1136 copy = state->offset - copy;
1137 if (copy > state->whave) {
1138 if (state->sane) {
1139 strm->msg = (char *)"invalid distance too far back";
1140 state->mode = BAD;
1141 break;
1142 }
1143 #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1144 Trace((stderr, "inflate.c too far\n"));
1145 copy -= state->whave;
1146 if (copy > state->length) copy = state->length;
1147 if (copy > left) copy = left;
1148 left -= copy;
1149 state->length -= copy;
1150 do {
1151 *put++ = 0;
1152 } while (--copy);
1153 if (state->length == 0) state->mode = LEN;
1154 break;
1155 #endif
1156 }
1157 if (copy > state->wnext) {
1158 copy -= state->wnext;
1159 from = state->window + (state->wsize - copy);
1160 }
1161 else
1162 from = state->window + (state->wnext - copy);
1163 if (copy > state->length) copy = state->length;
1164 }
1165 else { /* copy from output */
1166 from = put - state->offset;
1167 copy = state->length;
1168 }
1169 if (copy > left) copy = left;
1170 left -= copy;
1171 state->length -= copy;
1172 do {
1173 *put++ = *from++;
1174 } while (--copy);
1175 if (state->length == 0) state->mode = LEN;
1176 break;
1177 case LIT:
1178 if (left == 0) goto inf_leave;
1179 *put++ = (unsigned char)(state->length);
1180 left--;
1181 state->mode = LEN;
1182 break;
1183 case CHECK:
1184 if (state->wrap) {
1185 NEEDBITS(32);
1186 out -= left;
1187 strm->total_out += out;
1188 state->total += out;
1189 if (out)
1190 strm->adler = state->check =
1191 UPDATE(state->check, put - out, out);
1192 out = left;
1193 if ((
1194 #ifdef GUNZIP
1195 state->flags ? hold :
1196 #endif
1197 REVERSE(hold)) != state->check) {
1198 strm->msg = (char *)"incorrect data check";
1199 state->mode = BAD;
1200 break;
1201 }
1202 INITBITS();
1203 Tracev((stderr, "inflate: check matches trailer\n"));
1204 }
1205 #ifdef GUNZIP
1206 state->mode = LENGTH;
1207 case LENGTH:
1208 if (state->wrap && state->flags) {
1209 NEEDBITS(32);
1210 if (hold != (state->total & 0xffffffffUL)) {
1211 strm->msg = (char *)"incorrect length check";
1212 state->mode = BAD;
1213 break;
1214 }
1215 INITBITS();
1216 Tracev((stderr, "inflate: length matches trailer\n"));
1217 }
1218 #endif
1219 state->mode = DONE;
1220 case DONE:
1221 ret = Z_STREAM_END;
1222 goto inf_leave;
1223 case BAD:
1224 ret = Z_DATA_ERROR;
1225 goto inf_leave;
1226 case MEM:
1227 return Z_MEM_ERROR;
1228 case SYNC:
1229 default:
1230 return Z_STREAM_ERROR;
1231 }
1232
1233 /*
1234 Return from inflate(), updating the total counts and the check value.
1235 If there was no progress during the inflate() call, return a buffer
1236 error. Call updatewindow() to create and/or update the window state.
1237 Note: a memory error from inflate() is non-recoverable.
1238 */
1239 inf_leave:
1240 RESTORE();
1241 if (state->wsize || (state->mode < CHECK && out != strm->avail_out))
1242 if (updatewindow(strm, out)) {
1243 state->mode = MEM;
1244 return Z_MEM_ERROR;
1245 }
1246 in -= strm->avail_in;
1247 out -= strm->avail_out;
1248 strm->total_in += in;
1249 strm->total_out += out;
1250 state->total += out;
1251 if (state->wrap && out)
1252 strm->adler = state->check =
1253 UPDATE(state->check, strm->next_out - out, out);
1254 strm->data_type = state->bits + (state->last ? 64 : 0) +
1255 (state->mode == TYPE ? 128 : 0) +
1256 (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1257 if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1258 ret = Z_BUF_ERROR;
1259 return ret;
1260 }
1261
1262 int ZEXPORT inflateEnd(strm)
1263 z_streamp strm;
1264 {
1265 struct inflate_state FAR *state;
1266 if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
1267 return Z_STREAM_ERROR;
1268 state = (struct inflate_state FAR *)strm->state;
1269 if (state->window != Z_NULL) ZFREE(strm, state->window);
1270 ZFREE(strm, strm->state);
1271 strm->state = Z_NULL;
1272 Tracev((stderr, "inflate: end\n"));
1273 return Z_OK;
1274 }
1275
1276 int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
1277 z_streamp strm;
1278 const Bytef *dictionary;
1279 uInt dictLength;
1280 {
1281 struct inflate_state FAR *state;
1282 unsigned long id;
1283
1284 /* check state */
1285 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1286 state = (struct inflate_state FAR *)strm->state;
1287 if (state->wrap != 0 && state->mode != DICT)
1288 return Z_STREAM_ERROR;
1289
1290 /* check for correct dictionary id */
1291 if (state->mode == DICT) {
1292 id = adler32(0L, Z_NULL, 0);
1293 id = adler32(id, dictionary, dictLength);
1294 if (id != state->check)
1295 return Z_DATA_ERROR;
1296 }
1297
1298 /* copy dictionary to window */
1299 if (updatewindow(strm, strm->avail_out)) {
1300 state->mode = MEM;
1301 return Z_MEM_ERROR;
1302 }
1303 if (dictLength > state->wsize) {
1304 zmemcpy(state->window, dictionary + dictLength - state->wsize,
1305 state->wsize);
1306 state->whave = state->wsize;
1307 }
1308 else {
1309 zmemcpy(state->window + state->wsize - dictLength, dictionary,
1310 dictLength);
1311 state->whave = dictLength;
1312 }
1313 state->havedict = 1;
1314 Tracev((stderr, "inflate: dictionary set\n"));
1315 return Z_OK;
1316 }
1317
1318 int ZEXPORT inflateGetHeader(strm, head)
1319 z_streamp strm;
1320 gz_headerp head;
1321 {
1322 struct inflate_state FAR *state;
1323
1324 /* check state */
1325 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1326 state = (struct inflate_state FAR *)strm->state;
1327 if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
1328
1329 /* save header structure */
1330 state->head = head;
1331 head->done = 0;
1332 return Z_OK;
1333 }
1334
1335 /*
1336 Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found
1337 or when out of input. When called, *have is the number of pattern bytes
1338 found in order so far, in 0..3. On return *have is updated to the new
1339 state. If on return *have equals four, then the pattern was found and the
1340 return value is how many bytes were read including the last byte of the
1341 pattern. If *have is less than four, then the pattern has not been found
1342 yet and the return value is len. In the latter case, syncsearch() can be
1343 called again with more data and the *have state. *have is initialized to
1344 zero for the first call.
1345 */
1346 local unsigned syncsearch(have, buf, len)
1347 unsigned FAR *have;
1348 unsigned char FAR *buf;
1349 unsigned len;
1350 {
1351 unsigned got;
1352 unsigned next;
1353
1354 got = *have;
1355 next = 0;
1356 while (next < len && got < 4) {
1357 if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
1358 got++;
1359 else if (buf[next])
1360 got = 0;
1361 else
1362 got = 4 - got;
1363 next++;
1364 }
1365 *have = got;
1366 return next;
1367 }
1368
1369 int ZEXPORT inflateSync(strm)
1370 z_streamp strm;
1371 {
1372 unsigned len; /* number of bytes to look at or looked at */
1373 long long in, out; /* temporary to save total_in and total_out */
1374 unsigned char buf[4]; /* to restore bit buffer to byte string */
1375 struct inflate_state FAR *state;
1376
1377 /* check parameters */
1378 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1379 state = (struct inflate_state FAR *)strm->state;
1380 if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
1381
1382 /* if first time, start search in bit buffer */
1383 if (state->mode != SYNC) {
1384 state->mode = SYNC;
1385 state->hold <<= state->bits & 7;
1386 state->bits -= state->bits & 7;
1387 len = 0;
1388 while (state->bits >= 8) {
1389 buf[len++] = (unsigned char)(state->hold);
1390 state->hold >>= 8;
1391 state->bits -= 8;
1392 }
1393 state->have = 0;
1394 syncsearch(&(state->have), buf, len);
1395 }
1396
1397 /* search available input */
1398 len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
1399 strm->avail_in -= len;
1400 strm->next_in += len;
1401 strm->total_in += len;
1402
1403 /* return no joy or set up to restart inflate() on a new block */
1404 if (state->have != 4) return Z_DATA_ERROR;
1405 in = strm->total_in; out = strm->total_out;
1406 inflateReset(strm);
1407 strm->total_in = in; strm->total_out = out;
1408 state->mode = TYPE;
1409 return Z_OK;
1410 }
1411
1412 /*
1413 Returns true if inflate is currently at the end of a block generated by
1414 Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
1415 implementation to provide an additional safety check. PPP uses
1416 Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
1417 block. When decompressing, PPP checks that at the end of input packet,
1418 inflate is waiting for these length bytes.
1419 */
1420 int ZEXPORT inflateSyncPoint(strm)
1421 z_streamp strm;
1422 {
1423 struct inflate_state FAR *state;
1424
1425 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1426 state = (struct inflate_state FAR *)strm->state;
1427 return state->mode == STORED && state->bits == 0;
1428 }
1429
1430 int ZEXPORT inflateCopy(dest, source)
1431 z_streamp dest;
1432 z_streamp source;
1433 {
1434 struct inflate_state FAR *state;
1435 struct inflate_state FAR *copy;
1436 unsigned char FAR *window;
1437 unsigned wsize;
1438
1439 /* check input */
1440 if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL ||
1441 source->zalloc == (alloc_func)0 || source->zfree == (free_func)0)
1442 return Z_STREAM_ERROR;
1443 state = (struct inflate_state FAR *)source->state;
1444
1445 /* allocate space */
1446 copy = (struct inflate_state FAR *)
1447 ZALLOC(source, 1, sizeof(struct inflate_state));
1448 if (copy == Z_NULL) return Z_MEM_ERROR;
1449 window = Z_NULL;
1450 if (state->window != Z_NULL) {
1451 window = (unsigned char FAR *)
1452 ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
1453 if (window == Z_NULL) {
1454 ZFREE(source, copy);
1455 return Z_MEM_ERROR;
1456 }
1457 }
1458
1459 /* copy state */
1460 zmemcpy(dest, source, sizeof(z_stream));
1461 zmemcpy(copy, state, sizeof(struct inflate_state));
1462 if (state->lencode >= state->codes &&
1463 state->lencode <= state->codes + ENOUGH - 1) {
1464 copy->lencode = copy->codes + (state->lencode - state->codes);
1465 copy->distcode = copy->codes + (state->distcode - state->codes);
1466 }
1467 copy->next = copy->codes + (state->next - state->codes);
1468 if (window != Z_NULL) {
1469 wsize = 1U << state->wbits;
1470 zmemcpy(window, state->window, wsize);
1471 }
1472 copy->window = window;
1473 dest->state = (struct internal_state FAR *)copy;
1474 return Z_OK;
1475 }
1476
1477 int ZEXPORT inflateUndermine(strm, subvert)
1478 z_streamp strm;
1479 int subvert;
1480 {
1481 struct inflate_state FAR *state;
1482
1483 if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1484 state = (struct inflate_state FAR *)strm->state;
1485 state->sane = !subvert;
1486 #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1487 return Z_OK;
1488 #else
1489 state->sane = 1;
1490 return Z_DATA_ERROR;
1491 #endif
1492 }
1493
1494 long ZEXPORT inflateMark(strm)
1495 z_streamp strm;
1496 {
1497 struct inflate_state FAR *state;
1498
1499 if (strm == Z_NULL || strm->state == Z_NULL) return -1L << 16;
1500 state = (struct inflate_state FAR *)strm->state;
1501 return ((long)(state->back) << 16) +
1502 (state->mode == COPY ? state->length :
1503 (state->mode == MATCH ? state->was - state->length : 0));
1504 }