Annotation of sys/lib/libz/inflate.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: inflate.c,v 1.13 2005/07/20 15:56:46 millert Exp $ */
2: /* inflate.c -- zlib decompression
3: * Copyright (C) 1995-2005 Mark Adler
4: * For conditions of distribution and use, see copyright notice in zlib.h
5: */
6:
7: /*
8: * Change history:
9: *
10: * 1.2.beta0 24 Nov 2002
11: * - First version -- complete rewrite of inflate to simplify code, avoid
12: * creation of window when not needed, minimize use of window when it is
13: * needed, make inffast.c even faster, implement gzip decoding, and to
14: * improve code readability and style over the previous zlib inflate code
15: *
16: * 1.2.beta1 25 Nov 2002
17: * - Use pointers for available input and output checking in inffast.c
18: * - Remove input and output counters in inffast.c
19: * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
20: * - Remove unnecessary second byte pull from length extra in inffast.c
21: * - Unroll direct copy to three copies per loop in inffast.c
22: *
23: * 1.2.beta2 4 Dec 2002
24: * - Change external routine names to reduce potential conflicts
25: * - Correct filename to inffixed.h for fixed tables in inflate.c
26: * - Make hbuf[] unsigned char to match parameter type in inflate.c
27: * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
28: * to avoid negation problem on Alphas (64 bit) in inflate.c
29: *
30: * 1.2.beta3 22 Dec 2002
31: * - Add comments on state->bits assertion in inffast.c
32: * - Add comments on op field in inftrees.h
33: * - Fix bug in reuse of allocated window after inflateReset()
34: * - Remove bit fields--back to byte structure for speed
35: * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
36: * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
37: * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
38: * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
39: * - Use local copies of stream next and avail values, as well as local bit
40: * buffer and bit count in inflate()--for speed when inflate_fast() not used
41: *
42: * 1.2.beta4 1 Jan 2003
43: * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
44: * - Move a comment on output buffer sizes from inffast.c to inflate.c
45: * - Add comments in inffast.c to introduce the inflate_fast() routine
46: * - Rearrange window copies in inflate_fast() for speed and simplification
47: * - Unroll last copy for window match in inflate_fast()
48: * - Use local copies of window variables in inflate_fast() for speed
49: * - Pull out common write == 0 case for speed in inflate_fast()
50: * - Make op and len in inflate_fast() unsigned for consistency
51: * - Add FAR to lcode and dcode declarations in inflate_fast()
52: * - Simplified bad distance check in inflate_fast()
53: * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
54: * source file infback.c to provide a call-back interface to inflate for
55: * programs like gzip and unzip -- uses window as output buffer to avoid
56: * window copying
57: *
58: * 1.2.beta5 1 Jan 2003
59: * - Improved inflateBack() interface to allow the caller to provide initial
60: * input in strm.
61: * - Fixed stored blocks bug in inflateBack()
62: *
63: * 1.2.beta6 4 Jan 2003
64: * - Added comments in inffast.c on effectiveness of POSTINC
65: * - Typecasting all around to reduce compiler warnings
66: * - Changed loops from while (1) or do {} while (1) to for (;;), again to
67: * make compilers happy
68: * - Changed type of window in inflateBackInit() to unsigned char *
69: *
70: * 1.2.beta7 27 Jan 2003
71: * - Changed many types to unsigned or unsigned short to avoid warnings
72: * - Added inflateCopy() function
73: *
74: * 1.2.0 9 Mar 2003
75: * - Changed inflateBack() interface to provide separate opaque descriptors
76: * for the in() and out() functions
77: * - Changed inflateBack() argument and in_func typedef to swap the length
78: * and buffer address return values for the input function
79: * - Check next_in and next_out for Z_NULL on entry to inflate()
80: *
81: * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
82: */
83:
84: #include "zutil.h"
85: #include "inftrees.h"
86: #include "inflate.h"
87: #include "inffast.h"
88:
89: #ifdef MAKEFIXED
90: # ifndef BUILDFIXED
91: # define BUILDFIXED
92: # endif
93: #endif
94:
95: /* function prototypes */
96: local void fixedtables OF((struct inflate_state FAR *state));
97: local int updatewindow OF((z_streamp strm, unsigned out));
98: #ifdef BUILDFIXED
99: void makefixed OF((void));
100: #endif
101: local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf,
102: unsigned len));
103:
104: int ZEXPORT inflateReset(strm)
105: z_streamp strm;
106: {
107: struct inflate_state FAR *state;
108:
109: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
110: state = (struct inflate_state FAR *)strm->state;
111: strm->total_in = strm->total_out = state->total = 0;
112: strm->msg = Z_NULL;
113: strm->adler = 1; /* to support ill-conceived Java test suite */
114: state->mode = HEAD;
115: state->last = 0;
116: state->havedict = 0;
117: state->dmax = 32768U;
118: state->head = Z_NULL;
119: state->wsize = 0;
120: state->whave = 0;
121: state->write = 0;
122: state->hold = 0;
123: state->bits = 0;
124: state->lencode = state->distcode = state->next = state->codes;
125: Tracev((stderr, "inflate: reset\n"));
126: return Z_OK;
127: }
128:
129: int ZEXPORT inflatePrime(strm, bits, value)
130: z_streamp strm;
131: int bits;
132: int value;
133: {
134: struct inflate_state FAR *state;
135:
136: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
137: state = (struct inflate_state FAR *)strm->state;
138: if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
139: value &= (1L << bits) - 1;
140: state->hold += value << state->bits;
141: state->bits += bits;
142: return Z_OK;
143: }
144:
145: int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
146: z_streamp strm;
147: int windowBits;
148: const char *version;
149: int stream_size;
150: {
151: struct inflate_state FAR *state;
152:
153: if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
154: stream_size != (int)(sizeof(z_stream)))
155: return Z_VERSION_ERROR;
156: if (strm == Z_NULL) return Z_STREAM_ERROR;
157: strm->msg = Z_NULL; /* in case we return an error */
158: if (strm->zalloc == (alloc_func)0) {
159: strm->zalloc = zcalloc;
160: strm->opaque = (voidpf)0;
161: }
162: if (strm->zfree == (free_func)0) strm->zfree = zcfree;
163: state = (struct inflate_state FAR *)
164: ZALLOC(strm, 1, sizeof(struct inflate_state));
165: if (state == Z_NULL) return Z_MEM_ERROR;
166: Tracev((stderr, "inflate: allocated\n"));
167: strm->state = (struct internal_state FAR *)state;
168: if (windowBits < 0) {
169: state->wrap = 0;
170: windowBits = -windowBits;
171: }
172: else {
173: state->wrap = (windowBits >> 4) + 1;
174: #ifdef GUNZIP
175: if (windowBits < 48) windowBits &= 15;
176: #endif
177: }
178: if (windowBits < 8 || windowBits > 15) {
179: ZFREE(strm, state);
180: strm->state = Z_NULL;
181: return Z_STREAM_ERROR;
182: }
183: state->wbits = (unsigned)windowBits;
184: state->window = Z_NULL;
185: return inflateReset(strm);
186: }
187:
188: int ZEXPORT inflateInit_(strm, version, stream_size)
189: z_streamp strm;
190: const char *version;
191: int stream_size;
192: {
193: return inflateInit2_(strm, DEF_WBITS, version, stream_size);
194: }
195:
196: /*
197: Return state with length and distance decoding tables and index sizes set to
198: fixed code decoding. Normally this returns fixed tables from inffixed.h.
199: If BUILDFIXED is defined, then instead this routine builds the tables the
200: first time it's called, and returns those tables the first time and
201: thereafter. This reduces the size of the code by about 2K bytes, in
202: exchange for a little execution time. However, BUILDFIXED should not be
203: used for threaded applications, since the rewriting of the tables and virgin
204: may not be thread-safe.
205: */
206: local void fixedtables(state)
207: struct inflate_state FAR *state;
208: {
209: #ifdef BUILDFIXED
210: static int virgin = 1;
211: static code *lenfix, *distfix;
212: static code fixed[544];
213:
214: /* build fixed huffman tables if first call (may not be thread safe) */
215: if (virgin) {
216: unsigned sym, bits;
217: static code *next;
218:
219: /* literal/length table */
220: sym = 0;
221: while (sym < 144) state->lens[sym++] = 8;
222: while (sym < 256) state->lens[sym++] = 9;
223: while (sym < 280) state->lens[sym++] = 7;
224: while (sym < 288) state->lens[sym++] = 8;
225: next = fixed;
226: lenfix = next;
227: bits = 9;
228: inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
229:
230: /* distance table */
231: sym = 0;
232: while (sym < 32) state->lens[sym++] = 5;
233: distfix = next;
234: bits = 5;
235: inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
236:
237: /* do this just once */
238: virgin = 0;
239: }
240: #else /* !BUILDFIXED */
241: # include "inffixed.h"
242: #endif /* BUILDFIXED */
243: state->lencode = lenfix;
244: state->lenbits = 9;
245: state->distcode = distfix;
246: state->distbits = 5;
247: }
248:
249: #ifdef MAKEFIXED
250: #include <stdio.h>
251:
252: /*
253: Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also
254: defines BUILDFIXED, so the tables are built on the fly. makefixed() writes
255: those tables to stdout, which would be piped to inffixed.h. A small program
256: can simply call makefixed to do this:
257:
258: void makefixed(void);
259:
260: int main(void)
261: {
262: makefixed();
263: return 0;
264: }
265:
266: Then that can be linked with zlib built with MAKEFIXED defined and run:
267:
268: a.out > inffixed.h
269: */
270: void makefixed()
271: {
272: unsigned low, size;
273: struct inflate_state state;
274:
275: fixedtables(&state);
276: puts(" /* inffixed.h -- table for decoding fixed codes");
277: puts(" * Generated automatically by makefixed().");
278: puts(" */");
279: puts("");
280: puts(" /* WARNING: this file should *not* be used by applications.");
281: puts(" It is part of the implementation of this library and is");
282: puts(" subject to change. Applications should only use zlib.h.");
283: puts(" */");
284: puts("");
285: size = 1U << 9;
286: printf(" static const code lenfix[%u] = {", size);
287: low = 0;
288: for (;;) {
289: if ((low % 7) == 0) printf("\n ");
290: printf("{%u,%u,%d}", state.lencode[low].op, state.lencode[low].bits,
291: state.lencode[low].val);
292: if (++low == size) break;
293: putchar(',');
294: }
295: puts("\n };");
296: size = 1U << 5;
297: printf("\n static const code distfix[%u] = {", size);
298: low = 0;
299: for (;;) {
300: if ((low % 6) == 0) printf("\n ");
301: printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
302: state.distcode[low].val);
303: if (++low == size) break;
304: putchar(',');
305: }
306: puts("\n };");
307: }
308: #endif /* MAKEFIXED */
309:
310: /*
311: Update the window with the last wsize (normally 32K) bytes written before
312: returning. If window does not exist yet, create it. This is only called
313: when a window is already in use, or when output has been written during this
314: inflate call, but the end of the deflate stream has not been reached yet.
315: It is also called to create a window for dictionary data when a dictionary
316: is loaded.
317:
318: Providing output buffers larger than 32K to inflate() should provide a speed
319: advantage, since only the last 32K of output is copied to the sliding window
320: upon return from inflate(), and since all distances after the first 32K of
321: output will fall in the output data, making match copies simpler and faster.
322: The advantage may be dependent on the size of the processor's data caches.
323: */
324: local int updatewindow(strm, out)
325: z_streamp strm;
326: unsigned out;
327: {
328: struct inflate_state FAR *state;
329: unsigned copy, dist;
330:
331: state = (struct inflate_state FAR *)strm->state;
332:
333: /* if it hasn't been done already, allocate space for the window */
334: if (state->window == Z_NULL) {
335: state->window = (unsigned char FAR *)
336: ZALLOC(strm, 1U << state->wbits,
337: sizeof(unsigned char));
338: if (state->window == Z_NULL) return 1;
339: }
340:
341: /* if window not in use yet, initialize */
342: if (state->wsize == 0) {
343: state->wsize = 1U << state->wbits;
344: state->write = 0;
345: state->whave = 0;
346: }
347:
348: /* copy state->wsize or less output bytes into the circular window */
349: copy = out - strm->avail_out;
350: if (copy >= state->wsize) {
351: zmemcpy(state->window, strm->next_out - state->wsize, state->wsize);
352: state->write = 0;
353: state->whave = state->wsize;
354: }
355: else {
356: dist = state->wsize - state->write;
357: if (dist > copy) dist = copy;
358: zmemcpy(state->window + state->write, strm->next_out - copy, dist);
359: copy -= dist;
360: if (copy) {
361: zmemcpy(state->window, strm->next_out - copy, copy);
362: state->write = copy;
363: state->whave = state->wsize;
364: }
365: else {
366: state->write += dist;
367: if (state->write == state->wsize) state->write = 0;
368: if (state->whave < state->wsize) state->whave += dist;
369: }
370: }
371: return 0;
372: }
373:
374: /* Macros for inflate(): */
375:
376: /* check function to use adler32() for zlib or crc32() for gzip */
377: #ifdef GUNZIP
378: # define UPDATE(check, buf, len) \
379: (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
380: #else
381: # define UPDATE(check, buf, len) adler32(check, buf, len)
382: #endif
383:
384: /* check macros for header crc */
385: #ifdef GUNZIP
386: # define CRC2(check, word) \
387: do { \
388: hbuf[0] = (unsigned char)(word); \
389: hbuf[1] = (unsigned char)((word) >> 8); \
390: check = crc32(check, hbuf, 2); \
391: } while (0)
392:
393: # define CRC4(check, word) \
394: do { \
395: hbuf[0] = (unsigned char)(word); \
396: hbuf[1] = (unsigned char)((word) >> 8); \
397: hbuf[2] = (unsigned char)((word) >> 16); \
398: hbuf[3] = (unsigned char)((word) >> 24); \
399: check = crc32(check, hbuf, 4); \
400: } while (0)
401: #endif
402:
403: /* Load registers with state in inflate() for speed */
404: #define LOAD() \
405: do { \
406: put = strm->next_out; \
407: left = strm->avail_out; \
408: next = strm->next_in; \
409: have = strm->avail_in; \
410: hold = state->hold; \
411: bits = state->bits; \
412: } while (0)
413:
414: /* Restore state from registers in inflate() */
415: #define RESTORE() \
416: do { \
417: strm->next_out = put; \
418: strm->avail_out = left; \
419: strm->next_in = next; \
420: strm->avail_in = have; \
421: state->hold = hold; \
422: state->bits = bits; \
423: } while (0)
424:
425: /* Clear the input bit accumulator */
426: #define INITBITS() \
427: do { \
428: hold = 0; \
429: bits = 0; \
430: } while (0)
431:
432: /* Get a byte of input into the bit accumulator, or return from inflate()
433: if there is no input available. */
434: #define PULLBYTE() \
435: do { \
436: if (have == 0) goto inf_leave; \
437: have--; \
438: hold += (unsigned long)(*next++) << bits; \
439: bits += 8; \
440: } while (0)
441:
442: /* Assure that there are at least n bits in the bit accumulator. If there is
443: not enough available input to do that, then return from inflate(). */
444: #define NEEDBITS(n) \
445: do { \
446: while (bits < (unsigned)(n)) \
447: PULLBYTE(); \
448: } while (0)
449:
450: /* Return the low n bits of the bit accumulator (n < 16) */
451: #define BITS(n) \
452: ((unsigned)hold & ((1U << (n)) - 1))
453:
454: /* Remove n bits from the bit accumulator */
455: #define DROPBITS(n) \
456: do { \
457: hold >>= (n); \
458: bits -= (unsigned)(n); \
459: } while (0)
460:
461: /* Remove zero to seven bits as needed to go to a byte boundary */
462: #define BYTEBITS() \
463: do { \
464: hold >>= bits & 7; \
465: bits -= bits & 7; \
466: } while (0)
467:
468: /* Reverse the bytes in a 32-bit value */
469: #define REVERSE(q) \
470: ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
471: (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
472:
473: /*
474: inflate() uses a state machine to process as much input data and generate as
475: much output data as possible before returning. The state machine is
476: structured roughly as follows:
477:
478: for (;;) switch (state) {
479: ...
480: case STATEn:
481: if (not enough input data or output space to make progress)
482: return;
483: ... make progress ...
484: state = STATEm;
485: break;
486: ...
487: }
488:
489: so when inflate() is called again, the same case is attempted again, and
490: if the appropriate resources are provided, the machine proceeds to the
491: next state. The NEEDBITS() macro is usually the way the state evaluates
492: whether it can proceed or should return. NEEDBITS() does the return if
493: the requested bits are not available. The typical use of the BITS macros
494: is:
495:
496: NEEDBITS(n);
497: ... do something with BITS(n) ...
498: DROPBITS(n);
499:
500: where NEEDBITS(n) either returns from inflate() if there isn't enough
501: input left to load n bits into the accumulator, or it continues. BITS(n)
502: gives the low n bits in the accumulator. When done, DROPBITS(n) drops
503: the low n bits off the accumulator. INITBITS() clears the accumulator
504: and sets the number of available bits to zero. BYTEBITS() discards just
505: enough bits to put the accumulator on a byte boundary. After BYTEBITS()
506: and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
507:
508: NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
509: if there is no input available. The decoding of variable length codes uses
510: PULLBYTE() directly in order to pull just enough bytes to decode the next
511: code, and no more.
512:
513: Some states loop until they get enough input, making sure that enough
514: state information is maintained to continue the loop where it left off
515: if NEEDBITS() returns in the loop. For example, want, need, and keep
516: would all have to actually be part of the saved state in case NEEDBITS()
517: returns:
518:
519: case STATEw:
520: while (want < need) {
521: NEEDBITS(n);
522: keep[want++] = BITS(n);
523: DROPBITS(n);
524: }
525: state = STATEx;
526: case STATEx:
527:
528: As shown above, if the next state is also the next case, then the break
529: is omitted.
530:
531: A state may also return if there is not enough output space available to
532: complete that state. Those states are copying stored data, writing a
533: literal byte, and copying a matching string.
534:
535: When returning, a "goto inf_leave" is used to update the total counters,
536: update the check value, and determine whether any progress has been made
537: during that inflate() call in order to return the proper return code.
538: Progress is defined as a change in either strm->avail_in or strm->avail_out.
539: When there is a window, goto inf_leave will update the window with the last
540: output written. If a goto inf_leave occurs in the middle of decompression
541: and there is no window currently, goto inf_leave will create one and copy
542: output to the window for the next call of inflate().
543:
544: In this implementation, the flush parameter of inflate() only affects the
545: return code (per zlib.h). inflate() always writes as much as possible to
546: strm->next_out, given the space available and the provided input--the effect
547: documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
548: the allocation of and copying into a sliding window until necessary, which
549: provides the effect documented in zlib.h for Z_FINISH when the entire input
550: stream available. So the only thing the flush parameter actually does is:
551: when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
552: will return Z_BUF_ERROR if it has not reached the end of the stream.
553: */
554:
555: int ZEXPORT inflate(strm, flush)
556: z_streamp strm;
557: int flush;
558: {
559: struct inflate_state FAR *state;
560: unsigned char FAR *next; /* next input */
561: unsigned char FAR *put; /* next output */
562: unsigned have, left; /* available input and output */
563: unsigned long hold; /* bit buffer */
564: unsigned bits; /* bits in bit buffer */
565: unsigned in, out; /* save starting available input and output */
566: unsigned copy; /* number of stored or match bytes to copy */
567: unsigned char FAR *from; /* where to copy match bytes from */
568: code this; /* current decoding table entry */
569: code last; /* parent table entry */
570: unsigned len; /* length to copy for repeats, bits to drop */
571: int ret; /* return code */
572: #ifdef GUNZIP
573: unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
574: #endif
575: static const unsigned short order[19] = /* permutation of code lengths */
576: {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
577:
578: if (strm == Z_NULL || strm->state == Z_NULL ||
579: #ifndef __vax__
580: strm->next_out == Z_NULL ||
581: #endif
582: (strm->next_in == Z_NULL && strm->avail_in != 0))
583: return Z_STREAM_ERROR;
584:
585: state = (struct inflate_state FAR *)strm->state;
586: if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
587: LOAD();
588: in = have;
589: out = left;
590: ret = Z_OK;
591: for (;;)
592: switch (state->mode) {
593: case HEAD:
594: if (state->wrap == 0) {
595: state->mode = TYPEDO;
596: break;
597: }
598: NEEDBITS(16);
599: #ifdef GUNZIP
600: if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
601: state->check = crc32(0L, Z_NULL, 0);
602: CRC2(state->check, hold);
603: INITBITS();
604: state->mode = FLAGS;
605: break;
606: }
607: state->flags = 0; /* expect zlib header */
608: if (state->head != Z_NULL)
609: state->head->done = -1;
610: if (!(state->wrap & 1) || /* check if zlib header allowed */
611: #else
612: if (
613: #endif
614: ((BITS(8) << 8) + (hold >> 8)) % 31) {
615: #ifdef SMALL
616: strm->msg = "error";
617: #else
618: strm->msg = (char *)"incorrect header check";
619: #endif
620: state->mode = BAD;
621: break;
622: }
623: if (BITS(4) != Z_DEFLATED) {
624: #ifdef SMALL
625: strm->msg = "error";
626: #else
627: strm->msg = (char *)"unknown compression method";
628: #endif
629: state->mode = BAD;
630: break;
631: }
632: DROPBITS(4);
633: len = BITS(4) + 8;
634: if (len > state->wbits) {
635: #ifdef SMALL
636: strm->msg = "error";
637: #else
638: strm->msg = (char *)"invalid window size";
639: #endif
640: state->mode = BAD;
641: break;
642: }
643: state->dmax = 1U << len;
644: Tracev((stderr, "inflate: zlib header ok\n"));
645: strm->adler = state->check = adler32(0L, Z_NULL, 0);
646: state->mode = hold & 0x200 ? DICTID : TYPE;
647: INITBITS();
648: break;
649: #ifdef GUNZIP
650: case FLAGS:
651: NEEDBITS(16);
652: state->flags = (int)(hold);
653: if ((state->flags & 0xff) != Z_DEFLATED) {
654: #ifdef SMALL
655: strm->msg = "error";
656: #else
657: strm->msg = (char *)"unknown compression method";
658: #endif
659: state->mode = BAD;
660: break;
661: }
662: if (state->flags & 0xe000) {
663: #ifdef SMALL
664: strm->msg = "error";
665: #else
666: strm->msg = (char *)"unknown header flags set";
667: #endif
668: state->mode = BAD;
669: break;
670: }
671: if (state->head != Z_NULL)
672: state->head->text = (int)((hold >> 8) & 1);
673: if (state->flags & 0x0200) CRC2(state->check, hold);
674: INITBITS();
675: state->mode = TIME;
676: case TIME:
677: NEEDBITS(32);
678: if (state->head != Z_NULL)
679: state->head->time = hold;
680: if (state->flags & 0x0200) CRC4(state->check, hold);
681: INITBITS();
682: state->mode = OS;
683: case OS:
684: NEEDBITS(16);
685: if (state->head != Z_NULL) {
686: state->head->xflags = (int)(hold & 0xff);
687: state->head->os = (int)(hold >> 8);
688: }
689: if (state->flags & 0x0200) CRC2(state->check, hold);
690: INITBITS();
691: state->mode = EXLEN;
692: case EXLEN:
693: if (state->flags & 0x0400) {
694: NEEDBITS(16);
695: state->length = (unsigned)(hold);
696: if (state->head != Z_NULL)
697: state->head->extra_len = (unsigned)hold;
698: if (state->flags & 0x0200) CRC2(state->check, hold);
699: INITBITS();
700: }
701: else if (state->head != Z_NULL)
702: state->head->extra = Z_NULL;
703: state->mode = EXTRA;
704: case EXTRA:
705: if (state->flags & 0x0400) {
706: copy = state->length;
707: if (copy > have) copy = have;
708: if (copy) {
709: if (state->head != Z_NULL &&
710: state->head->extra != Z_NULL) {
711: len = state->head->extra_len - state->length;
712: zmemcpy(state->head->extra + len, next,
713: len + copy > state->head->extra_max ?
714: state->head->extra_max - len : copy);
715: }
716: if (state->flags & 0x0200)
717: state->check = crc32(state->check, next, copy);
718: have -= copy;
719: next += copy;
720: state->length -= copy;
721: }
722: if (state->length) goto inf_leave;
723: }
724: state->length = 0;
725: state->mode = NAME;
726: case NAME:
727: if (state->flags & 0x0800) {
728: if (have == 0) goto inf_leave;
729: copy = 0;
730: do {
731: len = (unsigned)(next[copy++]);
732: if (state->head != Z_NULL &&
733: state->head->name != Z_NULL &&
734: state->length < state->head->name_max)
735: state->head->name[state->length++] = len;
736: } while (len && copy < have);
737: if (state->flags & 0x0200)
738: state->check = crc32(state->check, next, copy);
739: have -= copy;
740: next += copy;
741: if (len) goto inf_leave;
742: }
743: else if (state->head != Z_NULL)
744: state->head->name = Z_NULL;
745: state->length = 0;
746: state->mode = COMMENT;
747: case COMMENT:
748: if (state->flags & 0x1000) {
749: if (have == 0) goto inf_leave;
750: copy = 0;
751: do {
752: len = (unsigned)(next[copy++]);
753: if (state->head != Z_NULL &&
754: state->head->comment != Z_NULL &&
755: state->length < state->head->comm_max)
756: state->head->comment[state->length++] = len;
757: } while (len && copy < have);
758: if (state->flags & 0x0200)
759: state->check = crc32(state->check, next, copy);
760: have -= copy;
761: next += copy;
762: if (len) goto inf_leave;
763: }
764: else if (state->head != Z_NULL)
765: state->head->comment = Z_NULL;
766: state->mode = HCRC;
767: case HCRC:
768: if (state->flags & 0x0200) {
769: NEEDBITS(16);
770: if (hold != (state->check & 0xffff)) {
771: #ifdef SMALL
772: strm->msg = "error";
773: #else
774: strm->msg = (char *)"header crc mismatch";
775: #endif
776: state->mode = BAD;
777: break;
778: }
779: INITBITS();
780: }
781: if (state->head != Z_NULL) {
782: state->head->hcrc = (int)((state->flags >> 9) & 1);
783: state->head->done = 1;
784: }
785: strm->adler = state->check = crc32(0L, Z_NULL, 0);
786: state->mode = TYPE;
787: break;
788: #endif
789: case DICTID:
790: NEEDBITS(32);
791: strm->adler = state->check = REVERSE(hold);
792: INITBITS();
793: state->mode = DICT;
794: case DICT:
795: if (state->havedict == 0) {
796: RESTORE();
797: return Z_NEED_DICT;
798: }
799: strm->adler = state->check = adler32(0L, Z_NULL, 0);
800: state->mode = TYPE;
801: case TYPE:
802: if (flush == Z_BLOCK) goto inf_leave;
803: case TYPEDO:
804: if (state->last) {
805: BYTEBITS();
806: state->mode = CHECK;
807: break;
808: }
809: NEEDBITS(3);
810: state->last = BITS(1);
811: DROPBITS(1);
812: switch (BITS(2)) {
813: case 0: /* stored block */
814: Tracev((stderr, "inflate: stored block%s\n",
815: state->last ? " (last)" : ""));
816: state->mode = STORED;
817: break;
818: case 1: /* fixed block */
819: fixedtables(state);
820: Tracev((stderr, "inflate: fixed codes block%s\n",
821: state->last ? " (last)" : ""));
822: state->mode = LEN; /* decode codes */
823: break;
824: case 2: /* dynamic block */
825: Tracev((stderr, "inflate: dynamic codes block%s\n",
826: state->last ? " (last)" : ""));
827: state->mode = TABLE;
828: break;
829: case 3:
830: #ifdef SMALL
831: strm->msg = "error";
832: #else
833: strm->msg = (char *)"invalid block type";
834: #endif
835: state->mode = BAD;
836: }
837: DROPBITS(2);
838: break;
839: case STORED:
840: BYTEBITS(); /* go to byte boundary */
841: NEEDBITS(32);
842: if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
843: #ifdef SMALL
844: strm->msg = "error";
845: #else
846: strm->msg = (char *)"invalid stored block lengths";
847: #endif
848: state->mode = BAD;
849: break;
850: }
851: state->length = (unsigned)hold & 0xffff;
852: Tracev((stderr, "inflate: stored length %u\n",
853: state->length));
854: INITBITS();
855: state->mode = COPY;
856: case COPY:
857: copy = state->length;
858: if (copy) {
859: if (copy > have) copy = have;
860: if (copy > left) copy = left;
861: if (copy == 0) goto inf_leave;
862: zmemcpy(put, next, copy);
863: have -= copy;
864: next += copy;
865: left -= copy;
866: put += copy;
867: state->length -= copy;
868: break;
869: }
870: Tracev((stderr, "inflate: stored end\n"));
871: state->mode = TYPE;
872: break;
873: case TABLE:
874: NEEDBITS(14);
875: state->nlen = BITS(5) + 257;
876: DROPBITS(5);
877: state->ndist = BITS(5) + 1;
878: DROPBITS(5);
879: state->ncode = BITS(4) + 4;
880: DROPBITS(4);
881: #ifndef PKZIP_BUG_WORKAROUND
882: if (state->nlen > 286 || state->ndist > 30) {
883: #ifdef SMALL
884: strm->msg = "error";
885: #else
886: strm->msg = (char *)"too many length or distance symbols";
887: #endif
888: state->mode = BAD;
889: break;
890: }
891: #endif
892: Tracev((stderr, "inflate: table sizes ok\n"));
893: state->have = 0;
894: state->mode = LENLENS;
895: case LENLENS:
896: while (state->have < state->ncode) {
897: NEEDBITS(3);
898: state->lens[order[state->have++]] = (unsigned short)BITS(3);
899: DROPBITS(3);
900: }
901: while (state->have < 19)
902: state->lens[order[state->have++]] = 0;
903: state->next = state->codes;
904: state->lencode = (code const FAR *)(state->next);
905: state->lenbits = 7;
906: ret = inflate_table(CODES, state->lens, 19, &(state->next),
907: &(state->lenbits), state->work);
908: if (ret) {
909: #ifdef SMALL
910: strm->msg = "error";
911: #else
912: strm->msg = (char *)"invalid code lengths set";
913: #endif
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: this = state->lencode[BITS(state->lenbits)];
924: if ((unsigned)(this.bits) <= bits) break;
925: PULLBYTE();
926: }
927: if (this.val < 16) {
928: NEEDBITS(this.bits);
929: DROPBITS(this.bits);
930: state->lens[state->have++] = this.val;
931: }
932: else {
933: if (this.val == 16) {
934: NEEDBITS(this.bits + 2);
935: DROPBITS(this.bits);
936: if (state->have == 0) {
937: #ifdef SMALL
938: strm->msg = "error";
939: #else
940: strm->msg = (char *)"invalid bit length repeat";
941: #endif
942: state->mode = BAD;
943: break;
944: }
945: len = state->lens[state->have - 1];
946: copy = 3 + BITS(2);
947: DROPBITS(2);
948: }
949: else if (this.val == 17) {
950: NEEDBITS(this.bits + 3);
951: DROPBITS(this.bits);
952: len = 0;
953: copy = 3 + BITS(3);
954: DROPBITS(3);
955: }
956: else {
957: NEEDBITS(this.bits + 7);
958: DROPBITS(this.bits);
959: len = 0;
960: copy = 11 + BITS(7);
961: DROPBITS(7);
962: }
963: if (state->have + copy > state->nlen + state->ndist) {
964: #ifdef SMALL
965: strm->msg = "error";
966: #else
967: strm->msg = (char *)"invalid bit length repeat";
968: #endif
969: state->mode = BAD;
970: break;
971: }
972: while (copy--)
973: state->lens[state->have++] = (unsigned short)len;
974: }
975: }
976:
977: /* handle error breaks in while */
978: if (state->mode == BAD) break;
979:
980: /* build code tables */
981: state->next = state->codes;
982: state->lencode = (code const FAR *)(state->next);
983: state->lenbits = 9;
984: ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
985: &(state->lenbits), state->work);
986: if (ret) {
987: #ifdef SMALL
988: strm->msg = "error";
989: #else
990: strm->msg = (char *)"invalid literal/lengths set";
991: #endif
992: state->mode = BAD;
993: break;
994: }
995: state->distcode = (code const FAR *)(state->next);
996: state->distbits = 6;
997: ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
998: &(state->next), &(state->distbits), state->work);
999: if (ret) {
1000: #ifdef SMALL
1001: strm->msg = "error";
1002: #else
1003: strm->msg = (char *)"invalid distances set";
1004: #endif
1005: state->mode = BAD;
1006: break;
1007: }
1008: Tracev((stderr, "inflate: codes ok\n"));
1009: state->mode = LEN;
1010: case LEN:
1011: #ifndef SLOW
1012: if (have >= 6 && left >= 258) {
1013: RESTORE();
1014: inflate_fast(strm, out);
1015: LOAD();
1016: break;
1017: }
1018: #endif
1019: for (;;) {
1020: this = state->lencode[BITS(state->lenbits)];
1021: if ((unsigned)(this.bits) <= bits) break;
1022: PULLBYTE();
1023: }
1024: if (this.op && (this.op & 0xf0) == 0) {
1025: last = this;
1026: for (;;) {
1027: this = state->lencode[last.val +
1028: (BITS(last.bits + last.op) >> last.bits)];
1029: if ((unsigned)(last.bits + this.bits) <= bits) break;
1030: PULLBYTE();
1031: }
1032: DROPBITS(last.bits);
1033: }
1034: DROPBITS(this.bits);
1035: state->length = (unsigned)this.val;
1036: if ((int)(this.op) == 0) {
1037: Tracevv((stderr, this.val >= 0x20 && this.val < 0x7f ?
1038: "inflate: literal '%c'\n" :
1039: "inflate: literal 0x%02x\n", this.val));
1040: state->mode = LIT;
1041: break;
1042: }
1043: if (this.op & 32) {
1044: Tracevv((stderr, "inflate: end of block\n"));
1045: state->mode = TYPE;
1046: break;
1047: }
1048: if (this.op & 64) {
1049: #ifdef SMALL
1050: strm->msg = "error";
1051: #else
1052: strm->msg = (char *)"invalid literal/length code";
1053: #endif
1054: state->mode = BAD;
1055: break;
1056: }
1057: state->extra = (unsigned)(this.op) & 15;
1058: state->mode = LENEXT;
1059: case LENEXT:
1060: if (state->extra) {
1061: NEEDBITS(state->extra);
1062: state->length += BITS(state->extra);
1063: DROPBITS(state->extra);
1064: }
1065: Tracevv((stderr, "inflate: length %u\n", state->length));
1066: state->mode = DIST;
1067: case DIST:
1068: for (;;) {
1069: this = state->distcode[BITS(state->distbits)];
1070: if ((unsigned)(this.bits) <= bits) break;
1071: PULLBYTE();
1072: }
1073: if ((this.op & 0xf0) == 0) {
1074: last = this;
1075: for (;;) {
1076: this = state->distcode[last.val +
1077: (BITS(last.bits + last.op) >> last.bits)];
1078: if ((unsigned)(last.bits + this.bits) <= bits) break;
1079: PULLBYTE();
1080: }
1081: DROPBITS(last.bits);
1082: }
1083: DROPBITS(this.bits);
1084: if (this.op & 64) {
1085: #ifdef SMALL
1086: strm->msg = "error";
1087: #else
1088: strm->msg = (char *)"invalid distance code";
1089: #endif
1090: state->mode = BAD;
1091: break;
1092: }
1093: state->offset = (unsigned)this.val;
1094: state->extra = (unsigned)(this.op) & 15;
1095: state->mode = DISTEXT;
1096: case DISTEXT:
1097: if (state->extra) {
1098: NEEDBITS(state->extra);
1099: state->offset += BITS(state->extra);
1100: DROPBITS(state->extra);
1101: }
1102: #ifdef INFLATE_STRICT
1103: if (state->offset > state->dmax) {
1104: strm->msg = (char *)"invalid distance too far back";
1105: state->mode = BAD;
1106: break;
1107: }
1108: #endif
1109: if (state->offset > state->whave + out - left) {
1110: #ifdef SMALL
1111: strm->msg = "error";
1112: #else
1113: strm->msg = (char *)"invalid distance too far back";
1114: #endif
1115: state->mode = BAD;
1116: break;
1117: }
1118: Tracevv((stderr, "inflate: distance %u\n", state->offset));
1119: state->mode = MATCH;
1120: case MATCH:
1121: if (left == 0) goto inf_leave;
1122: copy = out - left;
1123: if (state->offset > copy) { /* copy from window */
1124: copy = state->offset - copy;
1125: if (copy > state->write) {
1126: copy -= state->write;
1127: from = state->window + (state->wsize - copy);
1128: }
1129: else
1130: from = state->window + (state->write - copy);
1131: if (copy > state->length) copy = state->length;
1132: }
1133: else { /* copy from output */
1134: from = put - state->offset;
1135: copy = state->length;
1136: }
1137: if (copy > left) copy = left;
1138: left -= copy;
1139: state->length -= copy;
1140: do {
1141: *put++ = *from++;
1142: } while (--copy);
1143: if (state->length == 0) state->mode = LEN;
1144: break;
1145: case LIT:
1146: if (left == 0) goto inf_leave;
1147: *put++ = (unsigned char)(state->length);
1148: left--;
1149: state->mode = LEN;
1150: break;
1151: case CHECK:
1152: if (state->wrap) {
1153: NEEDBITS(32);
1154: out -= left;
1155: strm->total_out += out;
1156: state->total += out;
1157: if (out)
1158: strm->adler = state->check =
1159: UPDATE(state->check, put - out, out);
1160: out = left;
1161: if ((
1162: #ifdef GUNZIP
1163: state->flags ? hold :
1164: #endif
1165: REVERSE(hold)) != state->check) {
1166: #ifdef SMALL
1167: strm->msg = "error";
1168: #else
1169: strm->msg = (char *)"incorrect data check";
1170: #endif
1171: state->mode = BAD;
1172: break;
1173: }
1174: INITBITS();
1175: Tracev((stderr, "inflate: check matches trailer\n"));
1176: }
1177: #ifdef GUNZIP
1178: state->mode = LENGTH;
1179: case LENGTH:
1180: if (state->wrap && state->flags) {
1181: NEEDBITS(32);
1182: if (hold != (state->total & 0xffffffffUL)) {
1183: #ifdef SMALL
1184: strm->msg = "error";
1185: #else
1186: strm->msg = (char *)"incorrect length check";
1187: #endif
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: if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1233: ret = Z_BUF_ERROR;
1234: return ret;
1235: }
1236:
1237: int ZEXPORT inflateEnd(strm)
1238: z_streamp strm;
1239: {
1240: struct inflate_state FAR *state;
1241: if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
1242: return Z_STREAM_ERROR;
1243: state = (struct inflate_state FAR *)strm->state;
1244: if (state->window != Z_NULL) ZFREE(strm, state->window);
1245: ZFREE(strm, strm->state);
1246: strm->state = Z_NULL;
1247: Tracev((stderr, "inflate: end\n"));
1248: return Z_OK;
1249: }
1250:
1251: int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
1252: z_streamp strm;
1253: const Bytef *dictionary;
1254: uInt dictLength;
1255: {
1256: struct inflate_state FAR *state;
1257: unsigned long id;
1258:
1259: /* check state */
1260: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1261: state = (struct inflate_state FAR *)strm->state;
1262: if (state->wrap != 0 && state->mode != DICT)
1263: return Z_STREAM_ERROR;
1264:
1265: /* check for correct dictionary id */
1266: if (state->mode == DICT) {
1267: id = adler32(0L, Z_NULL, 0);
1268: id = adler32(id, dictionary, dictLength);
1269: if (id != state->check)
1270: return Z_DATA_ERROR;
1271: }
1272:
1273: /* copy dictionary to window */
1274: if (updatewindow(strm, strm->avail_out)) {
1275: state->mode = MEM;
1276: return Z_MEM_ERROR;
1277: }
1278: if (dictLength > state->wsize) {
1279: zmemcpy(state->window, dictionary + dictLength - state->wsize,
1280: state->wsize);
1281: state->whave = state->wsize;
1282: }
1283: else {
1284: zmemcpy(state->window + state->wsize - dictLength, dictionary,
1285: dictLength);
1286: state->whave = dictLength;
1287: }
1288: state->havedict = 1;
1289: Tracev((stderr, "inflate: dictionary set\n"));
1290: return Z_OK;
1291: }
1292:
1293: int ZEXPORT inflateGetHeader(strm, head)
1294: z_streamp strm;
1295: gz_headerp head;
1296: {
1297: struct inflate_state FAR *state;
1298:
1299: /* check state */
1300: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1301: state = (struct inflate_state FAR *)strm->state;
1302: if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
1303:
1304: /* save header structure */
1305: state->head = head;
1306: head->done = 0;
1307: return Z_OK;
1308: }
1309:
1310: /*
1311: Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found
1312: or when out of input. When called, *have is the number of pattern bytes
1313: found in order so far, in 0..3. On return *have is updated to the new
1314: state. If on return *have equals four, then the pattern was found and the
1315: return value is how many bytes were read including the last byte of the
1316: pattern. If *have is less than four, then the pattern has not been found
1317: yet and the return value is len. In the latter case, syncsearch() can be
1318: called again with more data and the *have state. *have is initialized to
1319: zero for the first call.
1320: */
1321: local unsigned syncsearch(have, buf, len)
1322: unsigned FAR *have;
1323: unsigned char FAR *buf;
1324: unsigned len;
1325: {
1326: unsigned got;
1327: unsigned next;
1328:
1329: got = *have;
1330: next = 0;
1331: while (next < len && got < 4) {
1332: if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
1333: got++;
1334: else if (buf[next])
1335: got = 0;
1336: else
1337: got = 4 - got;
1338: next++;
1339: }
1340: *have = got;
1341: return next;
1342: }
1343:
1344: int ZEXPORT inflateSync(strm)
1345: z_streamp strm;
1346: {
1347: unsigned len; /* number of bytes to look at or looked at */
1348: unsigned long in, out; /* temporary to save total_in and total_out */
1349: unsigned char buf[4]; /* to restore bit buffer to byte string */
1350: struct inflate_state FAR *state;
1351:
1352: /* check parameters */
1353: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1354: state = (struct inflate_state FAR *)strm->state;
1355: if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
1356:
1357: /* if first time, start search in bit buffer */
1358: if (state->mode != SYNC) {
1359: state->mode = SYNC;
1360: state->hold <<= state->bits & 7;
1361: state->bits -= state->bits & 7;
1362: len = 0;
1363: while (state->bits >= 8) {
1364: buf[len++] = (unsigned char)(state->hold);
1365: state->hold >>= 8;
1366: state->bits -= 8;
1367: }
1368: state->have = 0;
1369: syncsearch(&(state->have), buf, len);
1370: }
1371:
1372: /* search available input */
1373: len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
1374: strm->avail_in -= len;
1375: strm->next_in += len;
1376: strm->total_in += len;
1377:
1378: /* return no joy or set up to restart inflate() on a new block */
1379: if (state->have != 4) return Z_DATA_ERROR;
1380: in = strm->total_in; out = strm->total_out;
1381: inflateReset(strm);
1382: strm->total_in = in; strm->total_out = out;
1383: state->mode = TYPE;
1384: return Z_OK;
1385: }
1386:
1387: /*
1388: Returns true if inflate is currently at the end of a block generated by
1389: Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
1390: implementation to provide an additional safety check. PPP uses
1391: Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
1392: block. When decompressing, PPP checks that at the end of input packet,
1393: inflate is waiting for these length bytes.
1394: */
1395: int ZEXPORT inflateSyncPoint(strm)
1396: z_streamp strm;
1397: {
1398: struct inflate_state FAR *state;
1399:
1400: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1401: state = (struct inflate_state FAR *)strm->state;
1402: return state->mode == STORED && state->bits == 0;
1403: }
1404:
1405: int ZEXPORT inflateCopy(dest, source)
1406: z_streamp dest;
1407: z_streamp source;
1408: {
1409: struct inflate_state FAR *state;
1410: struct inflate_state FAR *copy;
1411: unsigned char FAR *window;
1412: unsigned wsize;
1413:
1414: /* check input */
1415: if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL ||
1416: source->zalloc == (alloc_func)0 || source->zfree == (free_func)0)
1417: return Z_STREAM_ERROR;
1418: state = (struct inflate_state FAR *)source->state;
1419:
1420: /* allocate space */
1421: copy = (struct inflate_state FAR *)
1422: ZALLOC(source, 1, sizeof(struct inflate_state));
1423: if (copy == Z_NULL) return Z_MEM_ERROR;
1424: window = Z_NULL;
1425: if (state->window != Z_NULL) {
1426: window = (unsigned char FAR *)
1427: ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
1428: if (window == Z_NULL) {
1429: ZFREE(source, copy);
1430: return Z_MEM_ERROR;
1431: }
1432: }
1433:
1434: /* copy state */
1435: zmemcpy(dest, source, sizeof(z_stream));
1436: zmemcpy(copy, state, sizeof(struct inflate_state));
1437: if (state->lencode >= state->codes &&
1438: state->lencode <= state->codes + ENOUGH - 1) {
1439: copy->lencode = copy->codes + (state->lencode - state->codes);
1440: copy->distcode = copy->codes + (state->distcode - state->codes);
1441: }
1442: copy->next = copy->codes + (state->next - state->codes);
1443: if (window != Z_NULL) {
1444: wsize = 1U << state->wbits;
1445: zmemcpy(window, state->window, wsize);
1446: }
1447: copy->window = window;
1448: dest->state = (struct internal_state FAR *)copy;
1449: return Z_OK;
1450: }
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