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1.8.7
1: /* inflate.c -- zlib decompression
2: * Copyright (C) 1995-2011 Mark Adler
3: * For conditions of distribution and use, see copyright notice in zlib.h
4: */
5:
6: /*
7: * Change history:
8: *
9: * 1.2.beta0 24 Nov 2002
10: * - First version -- complete rewrite of inflate to simplify code, avoid
11: * creation of window when not needed, minimize use of window when it is
12: * needed, make inffast.c even faster, implement gzip decoding, and to
13: * improve code readability and style over the previous zlib inflate code
14: *
15: * 1.2.beta1 25 Nov 2002
16: * - Use pointers for available input and output checking in inffast.c
17: * - Remove input and output counters in inffast.c
18: * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
19: * - Remove unnecessary second byte pull from length extra in inffast.c
20: * - Unroll direct copy to three copies per loop in inffast.c
21: *
22: * 1.2.beta2 4 Dec 2002
23: * - Change external routine names to reduce potential conflicts
24: * - Correct filename to inffixed.h for fixed tables in inflate.c
25: * - Make hbuf[] unsigned char to match parameter type in inflate.c
26: * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
27: * to avoid negation problem on Alphas (64 bit) in inflate.c
28: *
29: * 1.2.beta3 22 Dec 2002
30: * - Add comments on state->bits assertion in inffast.c
31: * - Add comments on op field in inftrees.h
32: * - Fix bug in reuse of allocated window after inflateReset()
33: * - Remove bit fields--back to byte structure for speed
34: * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
35: * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
36: * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
37: * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
38: * - Use local copies of stream next and avail values, as well as local bit
39: * buffer and bit count in inflate()--for speed when inflate_fast() not used
40: *
41: * 1.2.beta4 1 Jan 2003
42: * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
43: * - Move a comment on output buffer sizes from inffast.c to inflate.c
44: * - Add comments in inffast.c to introduce the inflate_fast() routine
45: * - Rearrange window copies in inflate_fast() for speed and simplification
46: * - Unroll last copy for window match in inflate_fast()
47: * - Use local copies of window variables in inflate_fast() for speed
48: * - Pull out common wnext == 0 case for speed in inflate_fast()
49: * - Make op and len in inflate_fast() unsigned for consistency
50: * - Add FAR to lcode and dcode declarations in inflate_fast()
51: * - Simplified bad distance check in inflate_fast()
52: * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
53: * source file infback.c to provide a call-back interface to inflate for
54: * programs like gzip and unzip -- uses window as output buffer to avoid
55: * window copying
56: *
57: * 1.2.beta5 1 Jan 2003
58: * - Improved inflateBack() interface to allow the caller to provide initial
59: * input in strm.
60: * - Fixed stored blocks bug in inflateBack()
61: *
62: * 1.2.beta6 4 Jan 2003
63: * - Added comments in inffast.c on effectiveness of POSTINC
64: * - Typecasting all around to reduce compiler warnings
65: * - Changed loops from while (1) or do {} while (1) to for (;;), again to
66: * make compilers happy
67: * - Changed type of window in inflateBackInit() to unsigned char *
68: *
69: * 1.2.beta7 27 Jan 2003
70: * - Changed many types to unsigned or unsigned short to avoid warnings
71: * - Added inflateCopy() function
72: *
73: * 1.2.0 9 Mar 2003
74: * - Changed inflateBack() interface to provide separate opaque descriptors
75: * for the in() and out() functions
76: * - Changed inflateBack() argument and in_func typedef to swap the length
77: * and buffer address return values for the input function
78: * - Check next_in and next_out for Z_NULL on entry to inflate()
79: *
80: * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
81: */
82:
83: #include "zutil.h"
84: #include "inftrees.h"
85: #include "inflate.h"
86: #include "inffast.h"
87:
88: #ifdef MAKEFIXED
89: # ifndef BUILDFIXED
90: # define BUILDFIXED
91: # endif
92: #endif
93:
94: /* function prototypes */
95: local void fixedtables OF((struct inflate_state FAR *state));
96: local int updatewindow OF((z_streamp strm, unsigned out));
97: #ifdef BUILDFIXED
98: void makefixed OF((void));
99: #endif
100: local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf,
101: unsigned len));
102:
103: int ZEXPORT inflateResetKeep(strm)
104: z_streamp strm;
105: {
106: struct inflate_state FAR *state;
107:
108: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
109: state = (struct inflate_state FAR *)strm->state;
110: strm->total_in = strm->total_out = state->total = 0;
111: strm->msg = Z_NULL;
112: if (state->wrap) /* to support ill-conceived Java test suite */
113: strm->adler = state->wrap & 1;
114: state->mode = HEAD;
115: state->last = 0;
116: state->havedict = 0;
117: state->dmax = 32768U;
118: state->head = Z_NULL;
119: state->hold = 0;
120: state->bits = 0;
121: state->lencode = state->distcode = state->next = state->codes;
122: state->sane = 1;
123: state->back = -1;
124: Tracev((stderr, "inflate: reset\n"));
125: return Z_OK;
126: }
127:
128: int ZEXPORT inflateReset(strm)
129: z_streamp strm;
130: {
131: struct inflate_state FAR *state;
132:
133: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
134: state = (struct inflate_state FAR *)strm->state;
135: state->wsize = 0;
136: state->whave = 0;
137: state->wnext = 0;
138: return inflateResetKeep(strm);
139: }
140:
141: int ZEXPORT inflateReset2(strm, windowBits)
142: z_streamp strm;
143: int windowBits;
144: {
145: int wrap;
146: struct inflate_state FAR *state;
147:
148: /* get the state */
149: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
150: state = (struct inflate_state FAR *)strm->state;
151:
152: /* extract wrap request from windowBits parameter */
153: if (windowBits < 0) {
154: wrap = 0;
155: windowBits = -windowBits;
156: }
157: else {
158: wrap = (windowBits >> 4) + 1;
159: #ifdef GUNZIP
160: if (windowBits < 48)
161: windowBits &= 15;
162: #endif
163: }
164:
165: /* set number of window bits, free window if different */
166: if (windowBits && (windowBits < 8 || windowBits > 15))
167: return Z_STREAM_ERROR;
168: if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
169: ZFREE(strm, state->window);
170: state->window = Z_NULL;
171: }
172:
173: /* update state and reset the rest of it */
174: state->wrap = wrap;
175: state->wbits = (unsigned)windowBits;
176: return inflateReset(strm);
177: }
178:
179: int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
180: z_streamp strm;
181: int windowBits;
182: const char *version;
183: int stream_size;
184: {
185: int ret;
186: struct inflate_state FAR *state;
187:
188: if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
189: stream_size != (int)(sizeof(z_stream)))
190: return Z_VERSION_ERROR;
191: if (strm == Z_NULL) return Z_STREAM_ERROR;
192: strm->msg = Z_NULL; /* in case we return an error */
193: if (strm->zalloc == (alloc_func)0) {
194: #ifdef Z_SOLO
195: return Z_STREAM_ERROR;
196: #else
197: strm->zalloc = zcalloc;
198: strm->opaque = (voidpf)0;
199: #endif
200: }
201: if (strm->zfree == (free_func)0)
202: #ifdef Z_SOLO
203: return Z_STREAM_ERROR;
204: #else
205: strm->zfree = zcfree;
206: #endif
207: state = (struct inflate_state FAR *)
208: ZALLOC(strm, 1, sizeof(struct inflate_state));
209: if (state == Z_NULL) return Z_MEM_ERROR;
210: Tracev((stderr, "inflate: allocated\n"));
211: strm->state = (struct internal_state FAR *)state;
212: state->window = Z_NULL;
213: ret = inflateReset2(strm, windowBits);
214: if (ret != Z_OK) {
215: ZFREE(strm, state);
216: strm->state = Z_NULL;
217: }
218: return ret;
219: }
220:
221: int ZEXPORT inflateInit_(strm, version, stream_size)
222: z_streamp strm;
223: const char *version;
224: int stream_size;
225: {
226: return inflateInit2_(strm, DEF_WBITS, version, stream_size);
227: }
228:
229: int ZEXPORT inflatePrime(strm, bits, value)
230: z_streamp strm;
231: int bits;
232: int value;
233: {
234: struct inflate_state FAR *state;
235:
236: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
237: state = (struct inflate_state FAR *)strm->state;
238: if (bits < 0) {
239: state->hold = 0;
240: state->bits = 0;
241: return Z_OK;
242: }
243: if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
244: value &= (1L << bits) - 1;
245: state->hold += value << state->bits;
246: state->bits += bits;
247: return Z_OK;
248: }
249:
250: /*
251: Return state with length and distance decoding tables and index sizes set to
252: fixed code decoding. Normally this returns fixed tables from inffixed.h.
253: If BUILDFIXED is defined, then instead this routine builds the tables the
254: first time it's called, and returns those tables the first time and
255: thereafter. This reduces the size of the code by about 2K bytes, in
256: exchange for a little execution time. However, BUILDFIXED should not be
257: used for threaded applications, since the rewriting of the tables and virgin
258: may not be thread-safe.
259: */
260: local void fixedtables(state)
261: struct inflate_state FAR *state;
262: {
263: #ifdef BUILDFIXED
264: static int virgin = 1;
265: static code *lenfix, *distfix;
266: static code fixed[544];
267:
268: /* build fixed huffman tables if first call (may not be thread safe) */
269: if (virgin) {
270: unsigned sym, bits;
271: static code *next;
272:
273: /* literal/length table */
274: sym = 0;
275: while (sym < 144) state->lens[sym++] = 8;
276: while (sym < 256) state->lens[sym++] = 9;
277: while (sym < 280) state->lens[sym++] = 7;
278: while (sym < 288) state->lens[sym++] = 8;
279: next = fixed;
280: lenfix = next;
281: bits = 9;
282: inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
283:
284: /* distance table */
285: sym = 0;
286: while (sym < 32) state->lens[sym++] = 5;
287: distfix = next;
288: bits = 5;
289: inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
290:
291: /* do this just once */
292: virgin = 0;
293: }
294: #else /* !BUILDFIXED */
295: # include "inffixed.h"
296: #endif /* BUILDFIXED */
297: state->lencode = lenfix;
298: state->lenbits = 9;
299: state->distcode = distfix;
300: state->distbits = 5;
301: }
302:
303: #ifdef MAKEFIXED
304: #include <stdio.h>
305:
306: /*
307: Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also
308: defines BUILDFIXED, so the tables are built on the fly. makefixed() writes
309: those tables to stdout, which would be piped to inffixed.h. A small program
310: can simply call makefixed to do this:
311:
312: void makefixed(void);
313:
314: int main(void)
315: {
316: makefixed();
317: return 0;
318: }
319:
320: Then that can be linked with zlib built with MAKEFIXED defined and run:
321:
322: a.out > inffixed.h
323: */
324: void makefixed()
325: {
326: unsigned low, size;
327: struct inflate_state state;
328:
329: fixedtables(&state);
330: puts(" /* inffixed.h -- table for decoding fixed codes");
331: puts(" * Generated automatically by makefixed().");
332: puts(" */");
333: puts("");
334: puts(" /* WARNING: this file should *not* be used by applications.");
335: puts(" It is part of the implementation of this library and is");
336: puts(" subject to change. Applications should only use zlib.h.");
337: puts(" */");
338: puts("");
339: size = 1U << 9;
340: printf(" static const code lenfix[%u] = {", size);
341: low = 0;
342: for (;;) {
343: if ((low % 7) == 0) printf("\n ");
344: printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op,
345: state.lencode[low].bits, state.lencode[low].val);
346: if (++low == size) break;
347: putchar(',');
348: }
349: puts("\n };");
350: size = 1U << 5;
351: printf("\n static const code distfix[%u] = {", size);
352: low = 0;
353: for (;;) {
354: if ((low % 6) == 0) printf("\n ");
355: printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
356: state.distcode[low].val);
357: if (++low == size) break;
358: putchar(',');
359: }
360: puts("\n };");
361: }
362: #endif /* MAKEFIXED */
363:
364: /*
365: Update the window with the last wsize (normally 32K) bytes written before
366: returning. If window does not exist yet, create it. This is only called
367: when a window is already in use, or when output has been written during this
368: inflate call, but the end of the deflate stream has not been reached yet.
369: It is also called to create a window for dictionary data when a dictionary
370: is loaded.
371:
372: Providing output buffers larger than 32K to inflate() should provide a speed
373: advantage, since only the last 32K of output is copied to the sliding window
374: upon return from inflate(), and since all distances after the first 32K of
375: output will fall in the output data, making match copies simpler and faster.
376: The advantage may be dependent on the size of the processor's data caches.
377: */
378: local int updatewindow(strm, out)
379: z_streamp strm;
380: unsigned out;
381: {
382: struct inflate_state FAR *state;
383: unsigned copy, dist;
384:
385: state = (struct inflate_state FAR *)strm->state;
386:
387: /* if it hasn't been done already, allocate space for the window */
388: if (state->window == Z_NULL) {
389: state->window = (unsigned char FAR *)
390: ZALLOC(strm, 1U << state->wbits,
391: sizeof(unsigned char));
392: if (state->window == Z_NULL) return 1;
393: }
394:
395: /* if window not in use yet, initialize */
396: if (state->wsize == 0) {
397: state->wsize = 1U << state->wbits;
398: state->wnext = 0;
399: state->whave = 0;
400: }
401:
402: /* copy state->wsize or less output bytes into the circular window */
403: copy = out - strm->avail_out;
404: if (copy >= state->wsize) {
405: zmemcpy(state->window, strm->next_out - state->wsize, state->wsize);
406: state->wnext = 0;
407: state->whave = state->wsize;
408: }
409: else {
410: dist = state->wsize - state->wnext;
411: if (dist > copy) dist = copy;
412: zmemcpy(state->window + state->wnext, strm->next_out - copy, dist);
413: copy -= dist;
414: if (copy) {
415: zmemcpy(state->window, strm->next_out - copy, copy);
416: state->wnext = copy;
417: state->whave = state->wsize;
418: }
419: else {
420: state->wnext += dist;
421: if (state->wnext == state->wsize) state->wnext = 0;
422: if (state->whave < state->wsize) state->whave += dist;
423: }
424: }
425: return 0;
426: }
427:
428: /* Macros for inflate(): */
429:
430: /* check function to use adler32() for zlib or crc32() for gzip */
431: #ifdef GUNZIP
432: # define UPDATE(check, buf, len) \
433: (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
434: #else
435: # define UPDATE(check, buf, len) adler32(check, buf, len)
436: #endif
437:
438: /* check macros for header crc */
439: #ifdef GUNZIP
440: # define CRC2(check, word) \
441: do { \
442: hbuf[0] = (unsigned char)(word); \
443: hbuf[1] = (unsigned char)((word) >> 8); \
444: check = crc32(check, hbuf, 2); \
445: } while (0)
446:
447: # define CRC4(check, word) \
448: do { \
449: hbuf[0] = (unsigned char)(word); \
450: hbuf[1] = (unsigned char)((word) >> 8); \
451: hbuf[2] = (unsigned char)((word) >> 16); \
452: hbuf[3] = (unsigned char)((word) >> 24); \
453: check = crc32(check, hbuf, 4); \
454: } while (0)
455: #endif
456:
457: /* Load registers with state in inflate() for speed */
458: #define LOAD() \
459: do { \
460: put = strm->next_out; \
461: left = strm->avail_out; \
462: next = strm->next_in; \
463: have = strm->avail_in; \
464: hold = state->hold; \
465: bits = state->bits; \
466: } while (0)
467:
468: /* Restore state from registers in inflate() */
469: #define RESTORE() \
470: do { \
471: strm->next_out = put; \
472: strm->avail_out = left; \
473: strm->next_in = next; \
474: strm->avail_in = have; \
475: state->hold = hold; \
476: state->bits = bits; \
477: } while (0)
478:
479: /* Clear the input bit accumulator */
480: #define INITBITS() \
481: do { \
482: hold = 0; \
483: bits = 0; \
484: } while (0)
485:
486: /* Get a byte of input into the bit accumulator, or return from inflate()
487: if there is no input available. */
488: #define PULLBYTE() \
489: do { \
490: if (have == 0) goto inf_leave; \
491: have--; \
492: hold += (unsigned long)(*next++) << bits; \
493: bits += 8; \
494: } while (0)
495:
496: /* Assure that there are at least n bits in the bit accumulator. If there is
497: not enough available input to do that, then return from inflate(). */
498: #define NEEDBITS(n) \
499: do { \
500: while (bits < (unsigned)(n)) \
501: PULLBYTE(); \
502: } while (0)
503:
504: /* Return the low n bits of the bit accumulator (n < 16) */
505: #define BITS(n) \
506: ((unsigned)hold & ((1U << (n)) - 1))
507:
508: /* Remove n bits from the bit accumulator */
509: #define DROPBITS(n) \
510: do { \
511: hold >>= (n); \
512: bits -= (unsigned)(n); \
513: } while (0)
514:
515: /* Remove zero to seven bits as needed to go to a byte boundary */
516: #define BYTEBITS() \
517: do { \
518: hold >>= bits & 7; \
519: bits -= bits & 7; \
520: } while (0)
521:
522: /* Reverse the bytes in a 32-bit value */
523: #define REVERSE(q) \
524: ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
525: (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
526:
527: /*
528: inflate() uses a state machine to process as much input data and generate as
529: much output data as possible before returning. The state machine is
530: structured roughly as follows:
531:
532: for (;;) switch (state) {
533: ...
534: case STATEn:
535: if (not enough input data or output space to make progress)
536: return;
537: ... make progress ...
538: state = STATEm;
539: break;
540: ...
541: }
542:
543: so when inflate() is called again, the same case is attempted again, and
544: if the appropriate resources are provided, the machine proceeds to the
545: next state. The NEEDBITS() macro is usually the way the state evaluates
546: whether it can proceed or should return. NEEDBITS() does the return if
547: the requested bits are not available. The typical use of the BITS macros
548: is:
549:
550: NEEDBITS(n);
551: ... do something with BITS(n) ...
552: DROPBITS(n);
553:
554: where NEEDBITS(n) either returns from inflate() if there isn't enough
555: input left to load n bits into the accumulator, or it continues. BITS(n)
556: gives the low n bits in the accumulator. When done, DROPBITS(n) drops
557: the low n bits off the accumulator. INITBITS() clears the accumulator
558: and sets the number of available bits to zero. BYTEBITS() discards just
559: enough bits to put the accumulator on a byte boundary. After BYTEBITS()
560: and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
561:
562: NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
563: if there is no input available. The decoding of variable length codes uses
564: PULLBYTE() directly in order to pull just enough bytes to decode the next
565: code, and no more.
566:
567: Some states loop until they get enough input, making sure that enough
568: state information is maintained to continue the loop where it left off
569: if NEEDBITS() returns in the loop. For example, want, need, and keep
570: would all have to actually be part of the saved state in case NEEDBITS()
571: returns:
572:
573: case STATEw:
574: while (want < need) {
575: NEEDBITS(n);
576: keep[want++] = BITS(n);
577: DROPBITS(n);
578: }
579: state = STATEx;
580: case STATEx:
581:
582: As shown above, if the next state is also the next case, then the break
583: is omitted.
584:
585: A state may also return if there is not enough output space available to
586: complete that state. Those states are copying stored data, writing a
587: literal byte, and copying a matching string.
588:
589: When returning, a "goto inf_leave" is used to update the total counters,
590: update the check value, and determine whether any progress has been made
591: during that inflate() call in order to return the proper return code.
592: Progress is defined as a change in either strm->avail_in or strm->avail_out.
593: When there is a window, goto inf_leave will update the window with the last
594: output written. If a goto inf_leave occurs in the middle of decompression
595: and there is no window currently, goto inf_leave will create one and copy
596: output to the window for the next call of inflate().
597:
598: In this implementation, the flush parameter of inflate() only affects the
599: return code (per zlib.h). inflate() always writes as much as possible to
600: strm->next_out, given the space available and the provided input--the effect
601: documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
602: the allocation of and copying into a sliding window until necessary, which
603: provides the effect documented in zlib.h for Z_FINISH when the entire input
604: stream available. So the only thing the flush parameter actually does is:
605: when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
606: will return Z_BUF_ERROR if it has not reached the end of the stream.
607: */
608:
609: int ZEXPORT inflate(strm, flush)
610: z_streamp strm;
611: int flush;
612: {
613: struct inflate_state FAR *state;
614: unsigned char FAR *next; /* next input */
615: unsigned char FAR *put; /* next output */
616: unsigned have, left; /* available input and output */
617: unsigned long hold; /* bit buffer */
618: unsigned bits; /* bits in bit buffer */
619: unsigned in, out; /* save starting available input and output */
620: unsigned copy; /* number of stored or match bytes to copy */
621: unsigned char FAR *from; /* where to copy match bytes from */
622: code here; /* current decoding table entry */
623: code last; /* parent table entry */
624: unsigned len; /* length to copy for repeats, bits to drop */
625: int ret; /* return code */
626: #ifdef GUNZIP
627: unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
628: #endif
629: static const unsigned short order[19] = /* permutation of code lengths */
630: {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
631:
632: if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL ||
633: (strm->next_in == Z_NULL && strm->avail_in != 0))
634: return Z_STREAM_ERROR;
635:
636: state = (struct inflate_state FAR *)strm->state;
637: if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
638: LOAD();
639: in = have;
640: out = left;
641: ret = Z_OK;
642: for (;;)
643: switch (state->mode) {
644: case HEAD:
645: if (state->wrap == 0) {
646: state->mode = TYPEDO;
647: break;
648: }
649: NEEDBITS(16);
650: #ifdef GUNZIP
651: if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
652: state->check = crc32(0L, Z_NULL, 0);
653: CRC2(state->check, hold);
654: INITBITS();
655: state->mode = FLAGS;
656: break;
657: }
658: state->flags = 0; /* expect zlib header */
659: if (state->head != Z_NULL)
660: state->head->done = -1;
661: if (!(state->wrap & 1) || /* check if zlib header allowed */
662: #else
663: if (
664: #endif
665: ((BITS(8) << 8) + (hold >> 8)) % 31) {
666: strm->msg = (char *)"incorrect header check";
667: state->mode = BAD;
668: break;
669: }
670: if (BITS(4) != Z_DEFLATED) {
671: strm->msg = (char *)"unknown compression method";
672: state->mode = BAD;
673: break;
674: }
675: DROPBITS(4);
676: len = BITS(4) + 8;
677: if (state->wbits == 0)
678: state->wbits = len;
679: else if (len > state->wbits) {
680: strm->msg = (char *)"invalid window size";
681: state->mode = BAD;
682: break;
683: }
684: state->dmax = 1U << len;
685: Tracev((stderr, "inflate: zlib header ok\n"));
686: strm->adler = state->check = adler32(0L, Z_NULL, 0);
687: state->mode = hold & 0x200 ? DICTID : TYPE;
688: INITBITS();
689: break;
690: #ifdef GUNZIP
691: case FLAGS:
692: NEEDBITS(16);
693: state->flags = (int)(hold);
694: if ((state->flags & 0xff) != Z_DEFLATED) {
695: strm->msg = (char *)"unknown compression method";
696: state->mode = BAD;
697: break;
698: }
699: if (state->flags & 0xe000) {
700: strm->msg = (char *)"unknown header flags set";
701: state->mode = BAD;
702: break;
703: }
704: if (state->head != Z_NULL)
705: state->head->text = (int)((hold >> 8) & 1);
706: if (state->flags & 0x0200) CRC2(state->check, hold);
707: INITBITS();
708: state->mode = TIME;
709: case TIME:
710: NEEDBITS(32);
711: if (state->head != Z_NULL)
712: state->head->time = hold;
713: if (state->flags & 0x0200) CRC4(state->check, hold);
714: INITBITS();
715: state->mode = OS;
716: case OS:
717: NEEDBITS(16);
718: if (state->head != Z_NULL) {
719: state->head->xflags = (int)(hold & 0xff);
720: state->head->os = (int)(hold >> 8);
721: }
722: if (state->flags & 0x0200) CRC2(state->check, hold);
723: INITBITS();
724: state->mode = EXLEN;
725: case EXLEN:
726: if (state->flags & 0x0400) {
727: NEEDBITS(16);
728: state->length = (unsigned)(hold);
729: if (state->head != Z_NULL)
730: state->head->extra_len = (unsigned)hold;
731: if (state->flags & 0x0200) CRC2(state->check, hold);
732: INITBITS();
733: }
734: else if (state->head != Z_NULL)
735: state->head->extra = Z_NULL;
736: state->mode = EXTRA;
737: case EXTRA:
738: if (state->flags & 0x0400) {
739: copy = state->length;
740: if (copy > have) copy = have;
741: if (copy) {
742: if (state->head != Z_NULL &&
743: state->head->extra != Z_NULL) {
744: len = state->head->extra_len - state->length;
745: zmemcpy(state->head->extra + len, next,
746: len + copy > state->head->extra_max ?
747: state->head->extra_max - len : copy);
748: }
749: if (state->flags & 0x0200)
750: state->check = crc32(state->check, next, copy);
751: have -= copy;
752: next += copy;
753: state->length -= copy;
754: }
755: if (state->length) goto inf_leave;
756: }
757: state->length = 0;
758: state->mode = NAME;
759: case NAME:
760: if (state->flags & 0x0800) {
761: if (have == 0) goto inf_leave;
762: copy = 0;
763: do {
764: len = (unsigned)(next[copy++]);
765: if (state->head != Z_NULL &&
766: state->head->name != Z_NULL &&
767: state->length < state->head->name_max)
768: state->head->name[state->length++] = len;
769: } while (len && copy < have);
770: if (state->flags & 0x0200)
771: state->check = crc32(state->check, next, copy);
772: have -= copy;
773: next += copy;
774: if (len) goto inf_leave;
775: }
776: else if (state->head != Z_NULL)
777: state->head->name = Z_NULL;
778: state->length = 0;
779: state->mode = COMMENT;
780: case COMMENT:
781: if (state->flags & 0x1000) {
782: if (have == 0) goto inf_leave;
783: copy = 0;
784: do {
785: len = (unsigned)(next[copy++]);
786: if (state->head != Z_NULL &&
787: state->head->comment != Z_NULL &&
788: state->length < state->head->comm_max)
789: state->head->comment[state->length++] = len;
790: } while (len && copy < have);
791: if (state->flags & 0x0200)
792: state->check = crc32(state->check, next, copy);
793: have -= copy;
794: next += copy;
795: if (len) goto inf_leave;
796: }
797: else if (state->head != Z_NULL)
798: state->head->comment = Z_NULL;
799: state->mode = HCRC;
800: case HCRC:
801: if (state->flags & 0x0200) {
802: NEEDBITS(16);
803: if (hold != (state->check & 0xffff)) {
804: strm->msg = (char *)"header crc mismatch";
805: state->mode = BAD;
806: break;
807: }
808: INITBITS();
809: }
810: if (state->head != Z_NULL) {
811: state->head->hcrc = (int)((state->flags >> 9) & 1);
812: state->head->done = 1;
813: }
814: strm->adler = state->check = crc32(0L, Z_NULL, 0);
815: state->mode = TYPE;
816: break;
817: #endif
818: case DICTID:
819: NEEDBITS(32);
820: strm->adler = state->check = REVERSE(hold);
821: INITBITS();
822: state->mode = DICT;
823: case DICT:
824: if (state->havedict == 0) {
825: RESTORE();
826: return Z_NEED_DICT;
827: }
828: strm->adler = state->check = adler32(0L, Z_NULL, 0);
829: state->mode = TYPE;
830: case TYPE:
831: if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
832: case TYPEDO:
833: if (state->last) {
834: BYTEBITS();
835: state->mode = CHECK;
836: break;
837: }
838: NEEDBITS(3);
839: state->last = BITS(1);
840: DROPBITS(1);
841: switch (BITS(2)) {
842: case 0: /* stored block */
843: Tracev((stderr, "inflate: stored block%s\n",
844: state->last ? " (last)" : ""));
845: state->mode = STORED;
846: break;
847: case 1: /* fixed block */
848: fixedtables(state);
849: Tracev((stderr, "inflate: fixed codes block%s\n",
850: state->last ? " (last)" : ""));
851: state->mode = LEN_; /* decode codes */
852: if (flush == Z_TREES) {
853: DROPBITS(2);
854: goto inf_leave;
855: }
856: break;
857: case 2: /* dynamic block */
858: Tracev((stderr, "inflate: dynamic codes block%s\n",
859: state->last ? " (last)" : ""));
860: state->mode = TABLE;
861: break;
862: case 3:
863: strm->msg = (char *)"invalid block type";
864: state->mode = BAD;
865: }
866: DROPBITS(2);
867: break;
868: case STORED:
869: BYTEBITS(); /* go to byte boundary */
870: NEEDBITS(32);
871: if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
872: strm->msg = (char *)"invalid stored block lengths";
873: state->mode = BAD;
874: break;
875: }
876: state->length = (unsigned)hold & 0xffff;
877: Tracev((stderr, "inflate: stored length %u\n",
878: state->length));
879: INITBITS();
880: state->mode = COPY_;
881: if (flush == Z_TREES) goto inf_leave;
882: case COPY_:
883: state->mode = COPY;
884: case COPY:
885: copy = state->length;
886: if (copy) {
887: if (copy > have) copy = have;
888: if (copy > left) copy = left;
889: if (copy == 0) goto inf_leave;
890: zmemcpy(put, next, copy);
891: have -= copy;
892: next += copy;
893: left -= copy;
894: put += copy;
895: state->length -= copy;
896: break;
897: }
898: Tracev((stderr, "inflate: stored end\n"));
899: state->mode = TYPE;
900: break;
901: case TABLE:
902: NEEDBITS(14);
903: state->nlen = BITS(5) + 257;
904: DROPBITS(5);
905: state->ndist = BITS(5) + 1;
906: DROPBITS(5);
907: state->ncode = BITS(4) + 4;
908: DROPBITS(4);
909: #ifndef PKZIP_BUG_WORKAROUND
910: if (state->nlen > 286 || state->ndist > 30) {
911: strm->msg = (char *)"too many length or distance symbols";
912: state->mode = BAD;
913: break;
914: }
915: #endif
916: Tracev((stderr, "inflate: table sizes ok\n"));
917: state->have = 0;
918: state->mode = LENLENS;
919: case LENLENS:
920: while (state->have < state->ncode) {
921: NEEDBITS(3);
922: state->lens[order[state->have++]] = (unsigned short)BITS(3);
923: DROPBITS(3);
924: }
925: while (state->have < 19)
926: state->lens[order[state->have++]] = 0;
927: state->next = state->codes;
928: state->lencode = (code const FAR *)(state->next);
929: state->lenbits = 7;
930: ret = inflate_table(CODES, state->lens, 19, &(state->next),
931: &(state->lenbits), state->work);
932: if (ret) {
933: strm->msg = (char *)"invalid code lengths set";
934: state->mode = BAD;
935: break;
936: }
937: Tracev((stderr, "inflate: code lengths ok\n"));
938: state->have = 0;
939: state->mode = CODELENS;
940: case CODELENS:
941: while (state->have < state->nlen + state->ndist) {
942: for (;;) {
943: here = state->lencode[BITS(state->lenbits)];
944: if ((unsigned)(here.bits) <= bits) break;
945: PULLBYTE();
946: }
947: if (here.val < 16) {
948: DROPBITS(here.bits);
949: state->lens[state->have++] = here.val;
950: }
951: else {
952: if (here.val == 16) {
953: NEEDBITS(here.bits + 2);
954: DROPBITS(here.bits);
955: if (state->have == 0) {
956: strm->msg = (char *)"invalid bit length repeat";
957: state->mode = BAD;
958: break;
959: }
960: len = state->lens[state->have - 1];
961: copy = 3 + BITS(2);
962: DROPBITS(2);
963: }
964: else if (here.val == 17) {
965: NEEDBITS(here.bits + 3);
966: DROPBITS(here.bits);
967: len = 0;
968: copy = 3 + BITS(3);
969: DROPBITS(3);
970: }
971: else {
972: NEEDBITS(here.bits + 7);
973: DROPBITS(here.bits);
974: len = 0;
975: copy = 11 + BITS(7);
976: DROPBITS(7);
977: }
978: if (state->have + copy > state->nlen + state->ndist) {
979: strm->msg = (char *)"invalid bit length repeat";
980: state->mode = BAD;
981: break;
982: }
983: while (copy--)
984: state->lens[state->have++] = (unsigned short)len;
985: }
986: }
987:
988: /* handle error breaks in while */
989: if (state->mode == BAD) break;
990:
991: /* check for end-of-block code (better have one) */
992: if (state->lens[256] == 0) {
993: strm->msg = (char *)"invalid code -- missing end-of-block";
994: state->mode = BAD;
995: break;
996: }
997:
998: /* build code tables -- note: do not change the lenbits or distbits
999: values here (9 and 6) without reading the comments in inftrees.h
1000: concerning the ENOUGH constants, which depend on those values */
1001: state->next = state->codes;
1002: state->lencode = (code const FAR *)(state->next);
1003: state->lenbits = 9;
1004: ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1005: &(state->lenbits), state->work);
1006: if (ret) {
1007: strm->msg = (char *)"invalid literal/lengths set";
1008: state->mode = BAD;
1009: break;
1010: }
1011: state->distcode = (code const FAR *)(state->next);
1012: state->distbits = 6;
1013: ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1014: &(state->next), &(state->distbits), state->work);
1015: if (ret) {
1016: strm->msg = (char *)"invalid distances set";
1017: state->mode = BAD;
1018: break;
1019: }
1020: Tracev((stderr, "inflate: codes ok\n"));
1021: state->mode = LEN_;
1022: if (flush == Z_TREES) goto inf_leave;
1023: case LEN_:
1024: state->mode = LEN;
1025: case LEN:
1026: if (have >= 6 && left >= 258) {
1027: RESTORE();
1028: inflate_fast(strm, out);
1029: LOAD();
1030: if (state->mode == TYPE)
1031: state->back = -1;
1032: break;
1033: }
1034: state->back = 0;
1035: for (;;) {
1036: here = state->lencode[BITS(state->lenbits)];
1037: if ((unsigned)(here.bits) <= bits) break;
1038: PULLBYTE();
1039: }
1040: if (here.op && (here.op & 0xf0) == 0) {
1041: last = here;
1042: for (;;) {
1043: here = state->lencode[last.val +
1044: (BITS(last.bits + last.op) >> last.bits)];
1045: if ((unsigned)(last.bits + here.bits) <= bits) break;
1046: PULLBYTE();
1047: }
1048: DROPBITS(last.bits);
1049: state->back += last.bits;
1050: }
1051: DROPBITS(here.bits);
1052: state->back += here.bits;
1053: state->length = (unsigned)here.val;
1054: if ((int)(here.op) == 0) {
1055: Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1056: "inflate: literal '%c'\n" :
1057: "inflate: literal 0x%02x\n", here.val));
1058: state->mode = LIT;
1059: break;
1060: }
1061: if (here.op & 32) {
1062: Tracevv((stderr, "inflate: end of block\n"));
1063: state->back = -1;
1064: state->mode = TYPE;
1065: break;
1066: }
1067: if (here.op & 64) {
1068: strm->msg = (char *)"invalid literal/length code";
1069: state->mode = BAD;
1070: break;
1071: }
1072: state->extra = (unsigned)(here.op) & 15;
1073: state->mode = LENEXT;
1074: case LENEXT:
1075: if (state->extra) {
1076: NEEDBITS(state->extra);
1077: state->length += BITS(state->extra);
1078: DROPBITS(state->extra);
1079: state->back += state->extra;
1080: }
1081: Tracevv((stderr, "inflate: length %u\n", state->length));
1082: state->was = state->length;
1083: state->mode = DIST;
1084: case DIST:
1085: for (;;) {
1086: here = state->distcode[BITS(state->distbits)];
1087: if ((unsigned)(here.bits) <= bits) break;
1088: PULLBYTE();
1089: }
1090: if ((here.op & 0xf0) == 0) {
1091: last = here;
1092: for (;;) {
1093: here = state->distcode[last.val +
1094: (BITS(last.bits + last.op) >> last.bits)];
1095: if ((unsigned)(last.bits + here.bits) <= bits) break;
1096: PULLBYTE();
1097: }
1098: DROPBITS(last.bits);
1099: state->back += last.bits;
1100: }
1101: DROPBITS(here.bits);
1102: state->back += here.bits;
1103: if (here.op & 64) {
1104: strm->msg = (char *)"invalid distance code";
1105: state->mode = BAD;
1106: break;
1107: }
1108: state->offset = (unsigned)here.val;
1109: state->extra = (unsigned)(here.op) & 15;
1110: state->mode = DISTEXT;
1111: case DISTEXT:
1112: if (state->extra) {
1113: NEEDBITS(state->extra);
1114: state->offset += BITS(state->extra);
1115: DROPBITS(state->extra);
1116: state->back += state->extra;
1117: }
1118: #ifdef INFLATE_STRICT
1119: if (state->offset > state->dmax) {
1120: strm->msg = (char *)"invalid distance too far back";
1121: state->mode = BAD;
1122: break;
1123: }
1124: #endif
1125: Tracevv((stderr, "inflate: distance %u\n", state->offset));
1126: state->mode = MATCH;
1127: case MATCH:
1128: if (left == 0) goto inf_leave;
1129: copy = out - left;
1130: if (state->offset > copy) { /* copy from window */
1131: copy = state->offset - copy;
1132: if (copy > state->whave) {
1133: if (state->sane) {
1134: strm->msg = (char *)"invalid distance too far back";
1135: state->mode = BAD;
1136: break;
1137: }
1138: #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1139: Trace((stderr, "inflate.c too far\n"));
1140: copy -= state->whave;
1141: if (copy > state->length) copy = state->length;
1142: if (copy > left) copy = left;
1143: left -= copy;
1144: state->length -= copy;
1145: do {
1146: *put++ = 0;
1147: } while (--copy);
1148: if (state->length == 0) state->mode = LEN;
1149: break;
1150: #endif
1151: }
1152: if (copy > state->wnext) {
1153: copy -= state->wnext;
1154: from = state->window + (state->wsize - copy);
1155: }
1156: else
1157: from = state->window + (state->wnext - copy);
1158: if (copy > state->length) copy = state->length;
1159: }
1160: else { /* copy from output */
1161: from = put - state->offset;
1162: copy = state->length;
1163: }
1164: if (copy > left) copy = left;
1165: left -= copy;
1166: state->length -= copy;
1167: do {
1168: *put++ = *from++;
1169: } while (--copy);
1170: if (state->length == 0) state->mode = LEN;
1171: break;
1172: case LIT:
1173: if (left == 0) goto inf_leave;
1174: *put++ = (unsigned char)(state->length);
1175: left--;
1176: state->mode = LEN;
1177: break;
1178: case CHECK:
1179: if (state->wrap) {
1180: NEEDBITS(32);
1181: out -= left;
1182: strm->total_out += out;
1183: state->total += out;
1184: if (out)
1185: strm->adler = state->check =
1186: UPDATE(state->check, put - out, out);
1187: out = left;
1188: if ((
1189: #ifdef GUNZIP
1190: state->flags ? hold :
1191: #endif
1192: REVERSE(hold)) != state->check) {
1193: strm->msg = (char *)"incorrect data check";
1194: state->mode = BAD;
1195: break;
1196: }
1197: INITBITS();
1198: Tracev((stderr, "inflate: check matches trailer\n"));
1199: }
1200: #ifdef GUNZIP
1201: state->mode = LENGTH;
1202: case LENGTH:
1203: if (state->wrap && state->flags) {
1204: NEEDBITS(32);
1205: if (hold != (state->total & 0xffffffffUL)) {
1206: strm->msg = (char *)"incorrect length check";
1207: state->mode = BAD;
1208: break;
1209: }
1210: INITBITS();
1211: Tracev((stderr, "inflate: length matches trailer\n"));
1212: }
1213: #endif
1214: state->mode = DONE;
1215: case DONE:
1216: ret = Z_STREAM_END;
1217: goto inf_leave;
1218: case BAD:
1219: ret = Z_DATA_ERROR;
1220: goto inf_leave;
1221: case MEM:
1222: return Z_MEM_ERROR;
1223: case SYNC:
1224: default:
1225: return Z_STREAM_ERROR;
1226: }
1227:
1228: /*
1229: Return from inflate(), updating the total counts and the check value.
1230: If there was no progress during the inflate() call, return a buffer
1231: error. Call updatewindow() to create and/or update the window state.
1232: Note: a memory error from inflate() is non-recoverable.
1233: */
1234: inf_leave:
1235: RESTORE();
1236: if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
1237: (state->mode < CHECK || flush != Z_FINISH)))
1238: if (updatewindow(strm, out)) {
1239: state->mode = MEM;
1240: return Z_MEM_ERROR;
1241: }
1242: in -= strm->avail_in;
1243: out -= strm->avail_out;
1244: strm->total_in += in;
1245: strm->total_out += out;
1246: state->total += out;
1247: if (state->wrap && out)
1248: strm->adler = state->check =
1249: UPDATE(state->check, strm->next_out - out, out);
1250: strm->data_type = state->bits + (state->last ? 64 : 0) +
1251: (state->mode == TYPE ? 128 : 0) +
1252: (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1253: if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1254: ret = Z_BUF_ERROR;
1255: return ret;
1256: }
1257:
1258: int ZEXPORT inflateEnd(strm)
1259: z_streamp strm;
1260: {
1261: struct inflate_state FAR *state;
1262: if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
1263: return Z_STREAM_ERROR;
1264: state = (struct inflate_state FAR *)strm->state;
1265: if (state->window != Z_NULL) ZFREE(strm, state->window);
1266: ZFREE(strm, strm->state);
1267: strm->state = Z_NULL;
1268: Tracev((stderr, "inflate: end\n"));
1269: return Z_OK;
1270: }
1271:
1272: int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
1273: z_streamp strm;
1274: const Bytef *dictionary;
1275: uInt dictLength;
1276: {
1277: struct inflate_state FAR *state;
1278: unsigned long id;
1279: unsigned char *next;
1280: unsigned avail;
1281: int ret;
1282:
1283: /* check state */
1284: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1285: state = (struct inflate_state FAR *)strm->state;
1286: if (state->wrap != 0 && state->mode != DICT)
1287: return Z_STREAM_ERROR;
1288:
1289: /* check for correct dictionary id */
1290: if (state->mode == DICT) {
1291: id = adler32(0L, Z_NULL, 0);
1292: id = adler32(id, dictionary, dictLength);
1293: if (id != state->check)
1294: return Z_DATA_ERROR;
1295: }
1296:
1297: /* copy dictionary to window using updatewindow(), which will amend the
1298: existing dictionary if appropriate */
1299: next = strm->next_out;
1300: avail = strm->avail_out;
1301: strm->next_out = (Bytef *)dictionary + dictLength;
1302: strm->avail_out = 0;
1303: ret = updatewindow(strm, dictLength);
1304: strm->avail_out = avail;
1305: strm->next_out = next;
1306: if (ret) {
1307: state->mode = MEM;
1308: return Z_MEM_ERROR;
1309: }
1310: state->havedict = 1;
1311: Tracev((stderr, "inflate: dictionary set\n"));
1312: return Z_OK;
1313: }
1314:
1315: int ZEXPORT inflateGetHeader(strm, head)
1316: z_streamp strm;
1317: gz_headerp head;
1318: {
1319: struct inflate_state FAR *state;
1320:
1321: /* check state */
1322: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1323: state = (struct inflate_state FAR *)strm->state;
1324: if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
1325:
1326: /* save header structure */
1327: state->head = head;
1328: head->done = 0;
1329: return Z_OK;
1330: }
1331:
1332: /*
1333: Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found
1334: or when out of input. When called, *have is the number of pattern bytes
1335: found in order so far, in 0..3. On return *have is updated to the new
1336: state. If on return *have equals four, then the pattern was found and the
1337: return value is how many bytes were read including the last byte of the
1338: pattern. If *have is less than four, then the pattern has not been found
1339: yet and the return value is len. In the latter case, syncsearch() can be
1340: called again with more data and the *have state. *have is initialized to
1341: zero for the first call.
1342: */
1343: local unsigned syncsearch(have, buf, len)
1344: unsigned FAR *have;
1345: unsigned char FAR *buf;
1346: unsigned len;
1347: {
1348: unsigned got;
1349: unsigned next;
1350:
1351: got = *have;
1352: next = 0;
1353: while (next < len && got < 4) {
1354: if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
1355: got++;
1356: else if (buf[next])
1357: got = 0;
1358: else
1359: got = 4 - got;
1360: next++;
1361: }
1362: *have = got;
1363: return next;
1364: }
1365:
1366: int ZEXPORT inflateSync(strm)
1367: z_streamp strm;
1368: {
1369: unsigned len; /* number of bytes to look at or looked at */
1370: unsigned long in, out; /* temporary to save total_in and total_out */
1371: unsigned char buf[4]; /* to restore bit buffer to byte string */
1372: struct inflate_state FAR *state;
1373:
1374: /* check parameters */
1375: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1376: state = (struct inflate_state FAR *)strm->state;
1377: if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
1378:
1379: /* if first time, start search in bit buffer */
1380: if (state->mode != SYNC) {
1381: state->mode = SYNC;
1382: state->hold <<= state->bits & 7;
1383: state->bits -= state->bits & 7;
1384: len = 0;
1385: while (state->bits >= 8) {
1386: buf[len++] = (unsigned char)(state->hold);
1387: state->hold >>= 8;
1388: state->bits -= 8;
1389: }
1390: state->have = 0;
1391: syncsearch(&(state->have), buf, len);
1392: }
1393:
1394: /* search available input */
1395: len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
1396: strm->avail_in -= len;
1397: strm->next_in += len;
1398: strm->total_in += len;
1399:
1400: /* return no joy or set up to restart inflate() on a new block */
1401: if (state->have != 4) return Z_DATA_ERROR;
1402: in = strm->total_in; out = strm->total_out;
1403: inflateReset(strm);
1404: strm->total_in = in; strm->total_out = out;
1405: state->mode = TYPE;
1406: return Z_OK;
1407: }
1408:
1409: /*
1410: Returns true if inflate is currently at the end of a block generated by
1411: Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
1412: implementation to provide an additional safety check. PPP uses
1413: Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
1414: block. When decompressing, PPP checks that at the end of input packet,
1415: inflate is waiting for these length bytes.
1416: */
1417: int ZEXPORT inflateSyncPoint(strm)
1418: z_streamp strm;
1419: {
1420: struct inflate_state FAR *state;
1421:
1422: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1423: state = (struct inflate_state FAR *)strm->state;
1424: return state->mode == STORED && state->bits == 0;
1425: }
1426:
1427: int ZEXPORT inflateCopy(dest, source)
1428: z_streamp dest;
1429: z_streamp source;
1430: {
1431: struct inflate_state FAR *state;
1432: struct inflate_state FAR *copy;
1433: unsigned char FAR *window;
1434: unsigned wsize;
1435:
1436: /* check input */
1437: if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL ||
1438: source->zalloc == (alloc_func)0 || source->zfree == (free_func)0)
1439: return Z_STREAM_ERROR;
1440: state = (struct inflate_state FAR *)source->state;
1441:
1442: /* allocate space */
1443: copy = (struct inflate_state FAR *)
1444: ZALLOC(source, 1, sizeof(struct inflate_state));
1445: if (copy == Z_NULL) return Z_MEM_ERROR;
1446: window = Z_NULL;
1447: if (state->window != Z_NULL) {
1448: window = (unsigned char FAR *)
1449: ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
1450: if (window == Z_NULL) {
1451: ZFREE(source, copy);
1452: return Z_MEM_ERROR;
1453: }
1454: }
1455:
1456: /* copy state */
1457: zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
1458: zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state));
1459: if (state->lencode >= state->codes &&
1460: state->lencode <= state->codes + ENOUGH - 1) {
1461: copy->lencode = copy->codes + (state->lencode - state->codes);
1462: copy->distcode = copy->codes + (state->distcode - state->codes);
1463: }
1464: copy->next = copy->codes + (state->next - state->codes);
1465: if (window != Z_NULL) {
1466: wsize = 1U << state->wbits;
1467: zmemcpy(window, state->window, wsize);
1468: }
1469: copy->window = window;
1470: dest->state = (struct internal_state FAR *)copy;
1471: return Z_OK;
1472: }
1473:
1474: int ZEXPORT inflateUndermine(strm, subvert)
1475: z_streamp strm;
1476: int subvert;
1477: {
1478: struct inflate_state FAR *state;
1479:
1480: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1481: state = (struct inflate_state FAR *)strm->state;
1482: state->sane = !subvert;
1483: #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1484: return Z_OK;
1485: #else
1486: state->sane = 1;
1487: return Z_DATA_ERROR;
1488: #endif
1489: }
1490:
1491: long ZEXPORT inflateMark(strm)
1492: z_streamp strm;
1493: {
1494: struct inflate_state FAR *state;
1495:
1496: if (strm == Z_NULL || strm->state == Z_NULL) return -1L << 16;
1497: state = (struct inflate_state FAR *)strm->state;
1498: return ((long)(state->back) << 16) +
1499: (state->mode == COPY ? state->length :
1500: (state->mode == MATCH ? state->was - state->length : 0));
1501: }
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