1: /* inflate.c -- zlib decompression
2: * Copyright (C) 1995-2012 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, const unsigned char FAR *end,
97: unsigned copy));
98: #ifdef BUILDFIXED
99: void makefixed OF((void));
100: #endif
101: local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf,
102: unsigned len));
103:
104: int ZEXPORT inflateResetKeep(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: if (state->wrap) /* to support ill-conceived Java test suite */
114: strm->adler = state->wrap & 1;
115: state->mode = HEAD;
116: state->last = 0;
117: state->havedict = 0;
118: state->dmax = 32768U;
119: state->head = Z_NULL;
120: state->hold = 0;
121: state->bits = 0;
122: state->lencode = state->distcode = state->next = state->codes;
123: state->sane = 1;
124: state->back = -1;
125: Tracev((stderr, "inflate: reset\n"));
126: return Z_OK;
127: }
128:
129: int ZEXPORT inflateReset(strm)
130: z_streamp strm;
131: {
132: struct inflate_state FAR *state;
133:
134: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
135: state = (struct inflate_state FAR *)strm->state;
136: state->wsize = 0;
137: state->whave = 0;
138: state->wnext = 0;
139: return inflateResetKeep(strm);
140: }
141:
142: int ZEXPORT inflateReset2(strm, windowBits)
143: z_streamp strm;
144: int windowBits;
145: {
146: int wrap;
147: struct inflate_state FAR *state;
148:
149: /* get the state */
150: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
151: state = (struct inflate_state FAR *)strm->state;
152:
153: /* extract wrap request from windowBits parameter */
154: if (windowBits < 0) {
155: wrap = 0;
156: windowBits = -windowBits;
157: }
158: else {
159: wrap = (windowBits >> 4) + 1;
160: #ifdef GUNZIP
161: if (windowBits < 48)
162: windowBits &= 15;
163: #endif
164: }
165:
166: /* set number of window bits, free window if different */
167: if (windowBits && (windowBits < 8 || windowBits > 15))
168: return Z_STREAM_ERROR;
169: if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
170: ZFREE(strm, state->window);
171: state->window = Z_NULL;
172: }
173:
174: /* update state and reset the rest of it */
175: state->wrap = wrap;
176: state->wbits = (unsigned)windowBits;
177: return inflateReset(strm);
178: }
179:
180: int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
181: z_streamp strm;
182: int windowBits;
183: const char *version;
184: int stream_size;
185: {
186: int ret;
187: struct inflate_state FAR *state;
188:
189: if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
190: stream_size != (int)(sizeof(z_stream)))
191: return Z_VERSION_ERROR;
192: if (strm == Z_NULL) return Z_STREAM_ERROR;
193: strm->msg = Z_NULL; /* in case we return an error */
194: if (strm->zalloc == (alloc_func)0) {
195: #ifdef Z_SOLO
196: return Z_STREAM_ERROR;
197: #else
198: strm->zalloc = zcalloc;
199: strm->opaque = (voidpf)0;
200: #endif
201: }
202: if (strm->zfree == (free_func)0)
203: #ifdef Z_SOLO
204: return Z_STREAM_ERROR;
205: #else
206: strm->zfree = zcfree;
207: #endif
208: state = (struct inflate_state FAR *)
209: ZALLOC(strm, 1, sizeof(struct inflate_state));
210: if (state == Z_NULL) return Z_MEM_ERROR;
211: Tracev((stderr, "inflate: allocated\n"));
212: strm->state = (struct internal_state FAR *)state;
213: state->window = Z_NULL;
214: ret = inflateReset2(strm, windowBits);
215: if (ret != Z_OK) {
216: ZFREE(strm, state);
217: strm->state = Z_NULL;
218: }
219: return ret;
220: }
221:
222: int ZEXPORT inflateInit_(strm, version, stream_size)
223: z_streamp strm;
224: const char *version;
225: int stream_size;
226: {
227: return inflateInit2_(strm, DEF_WBITS, version, stream_size);
228: }
229:
230: int ZEXPORT inflatePrime(strm, bits, value)
231: z_streamp strm;
232: int bits;
233: int value;
234: {
235: struct inflate_state FAR *state;
236:
237: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
238: state = (struct inflate_state FAR *)strm->state;
239: if (bits < 0) {
240: state->hold = 0;
241: state->bits = 0;
242: return Z_OK;
243: }
244: if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
245: value &= (1L << bits) - 1;
246: state->hold += value << state->bits;
247: state->bits += bits;
248: return Z_OK;
249: }
250:
251: /*
252: Return state with length and distance decoding tables and index sizes set to
253: fixed code decoding. Normally this returns fixed tables from inffixed.h.
254: If BUILDFIXED is defined, then instead this routine builds the tables the
255: first time it's called, and returns those tables the first time and
256: thereafter. This reduces the size of the code by about 2K bytes, in
257: exchange for a little execution time. However, BUILDFIXED should not be
258: used for threaded applications, since the rewriting of the tables and virgin
259: may not be thread-safe.
260: */
261: local void fixedtables(state)
262: struct inflate_state FAR *state;
263: {
264: #ifdef BUILDFIXED
265: static int virgin = 1;
266: static code *lenfix, *distfix;
267: static code fixed[544];
268:
269: /* build fixed huffman tables if first call (may not be thread safe) */
270: if (virgin) {
271: unsigned sym, bits;
272: static code *next;
273:
274: /* literal/length table */
275: sym = 0;
276: while (sym < 144) state->lens[sym++] = 8;
277: while (sym < 256) state->lens[sym++] = 9;
278: while (sym < 280) state->lens[sym++] = 7;
279: while (sym < 288) state->lens[sym++] = 8;
280: next = fixed;
281: lenfix = next;
282: bits = 9;
283: inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
284:
285: /* distance table */
286: sym = 0;
287: while (sym < 32) state->lens[sym++] = 5;
288: distfix = next;
289: bits = 5;
290: inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
291:
292: /* do this just once */
293: virgin = 0;
294: }
295: #else /* !BUILDFIXED */
296: # include "inffixed.h"
297: #endif /* BUILDFIXED */
298: state->lencode = lenfix;
299: state->lenbits = 9;
300: state->distcode = distfix;
301: state->distbits = 5;
302: }
303:
304: #ifdef MAKEFIXED
305: #include <stdio.h>
306:
307: /*
308: Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also
309: defines BUILDFIXED, so the tables are built on the fly. makefixed() writes
310: those tables to stdout, which would be piped to inffixed.h. A small program
311: can simply call makefixed to do this:
312:
313: void makefixed(void);
314:
315: int main(void)
316: {
317: makefixed();
318: return 0;
319: }
320:
321: Then that can be linked with zlib built with MAKEFIXED defined and run:
322:
323: a.out > inffixed.h
324: */
325: void makefixed()
326: {
327: unsigned low, size;
328: struct inflate_state state;
329:
330: fixedtables(&state);
331: puts(" /* inffixed.h -- table for decoding fixed codes");
332: puts(" * Generated automatically by makefixed().");
333: puts(" */");
334: puts("");
335: puts(" /* WARNING: this file should *not* be used by applications.");
336: puts(" It is part of the implementation of this library and is");
337: puts(" subject to change. Applications should only use zlib.h.");
338: puts(" */");
339: puts("");
340: size = 1U << 9;
341: printf(" static const code lenfix[%u] = {", size);
342: low = 0;
343: for (;;) {
344: if ((low % 7) == 0) printf("\n ");
345: printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op,
346: state.lencode[low].bits, state.lencode[low].val);
347: if (++low == size) break;
348: putchar(',');
349: }
350: puts("\n };");
351: size = 1U << 5;
352: printf("\n static const code distfix[%u] = {", size);
353: low = 0;
354: for (;;) {
355: if ((low % 6) == 0) printf("\n ");
356: printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
357: state.distcode[low].val);
358: if (++low == size) break;
359: putchar(',');
360: }
361: puts("\n };");
362: }
363: #endif /* MAKEFIXED */
364:
365: /*
366: Update the window with the last wsize (normally 32K) bytes written before
367: returning. If window does not exist yet, create it. This is only called
368: when a window is already in use, or when output has been written during this
369: inflate call, but the end of the deflate stream has not been reached yet.
370: It is also called to create a window for dictionary data when a dictionary
371: is loaded.
372:
373: Providing output buffers larger than 32K to inflate() should provide a speed
374: advantage, since only the last 32K of output is copied to the sliding window
375: upon return from inflate(), and since all distances after the first 32K of
376: output will fall in the output data, making match copies simpler and faster.
377: The advantage may be dependent on the size of the processor's data caches.
378: */
379: local int updatewindow(strm, end, copy)
380: z_streamp strm;
381: const Bytef *end;
382: unsigned copy;
383: {
384: struct inflate_state FAR *state;
385: unsigned dist;
386:
387: state = (struct inflate_state FAR *)strm->state;
388:
389: /* if it hasn't been done already, allocate space for the window */
390: if (state->window == Z_NULL) {
391: state->window = (unsigned char FAR *)
392: ZALLOC(strm, 1U << state->wbits,
393: sizeof(unsigned char));
394: if (state->window == Z_NULL) return 1;
395: }
396:
397: /* if window not in use yet, initialize */
398: if (state->wsize == 0) {
399: state->wsize = 1U << state->wbits;
400: state->wnext = 0;
401: state->whave = 0;
402: }
403:
404: /* copy state->wsize or less output bytes into the circular window */
405: if (copy >= state->wsize) {
406: zmemcpy(state->window, end - state->wsize, state->wsize);
407: state->wnext = 0;
408: state->whave = state->wsize;
409: }
410: else {
411: dist = state->wsize - state->wnext;
412: if (dist > copy) dist = copy;
413: zmemcpy(state->window + state->wnext, end - copy, dist);
414: copy -= dist;
415: if (copy) {
416: zmemcpy(state->window, end - copy, copy);
417: state->wnext = copy;
418: state->whave = state->wsize;
419: }
420: else {
421: state->wnext += dist;
422: if (state->wnext == state->wsize) state->wnext = 0;
423: if (state->whave < state->wsize) state->whave += dist;
424: }
425: }
426: return 0;
427: }
428:
429: /* Macros for inflate(): */
430:
431: /* check function to use adler32() for zlib or crc32() for gzip */
432: #ifdef GUNZIP
433: # define UPDATE(check, buf, len) \
434: (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
435: #else
436: # define UPDATE(check, buf, len) adler32(check, buf, len)
437: #endif
438:
439: /* check macros for header crc */
440: #ifdef GUNZIP
441: # define CRC2(check, word) \
442: do { \
443: hbuf[0] = (unsigned char)(word); \
444: hbuf[1] = (unsigned char)((word) >> 8); \
445: check = crc32(check, hbuf, 2); \
446: } while (0)
447:
448: # define CRC4(check, word) \
449: do { \
450: hbuf[0] = (unsigned char)(word); \
451: hbuf[1] = (unsigned char)((word) >> 8); \
452: hbuf[2] = (unsigned char)((word) >> 16); \
453: hbuf[3] = (unsigned char)((word) >> 24); \
454: check = crc32(check, hbuf, 4); \
455: } while (0)
456: #endif
457:
458: /* Load registers with state in inflate() for speed */
459: #define LOAD() \
460: do { \
461: put = strm->next_out; \
462: left = strm->avail_out; \
463: next = strm->next_in; \
464: have = strm->avail_in; \
465: hold = state->hold; \
466: bits = state->bits; \
467: } while (0)
468:
469: /* Restore state from registers in inflate() */
470: #define RESTORE() \
471: do { \
472: strm->next_out = put; \
473: strm->avail_out = left; \
474: strm->next_in = next; \
475: strm->avail_in = have; \
476: state->hold = hold; \
477: state->bits = bits; \
478: } while (0)
479:
480: /* Clear the input bit accumulator */
481: #define INITBITS() \
482: do { \
483: hold = 0; \
484: bits = 0; \
485: } while (0)
486:
487: /* Get a byte of input into the bit accumulator, or return from inflate()
488: if there is no input available. */
489: #define PULLBYTE() \
490: do { \
491: if (have == 0) goto inf_leave; \
492: have--; \
493: hold += (unsigned long)(*next++) << bits; \
494: bits += 8; \
495: } while (0)
496:
497: /* Assure that there are at least n bits in the bit accumulator. If there is
498: not enough available input to do that, then return from inflate(). */
499: #define NEEDBITS(n) \
500: do { \
501: while (bits < (unsigned)(n)) \
502: PULLBYTE(); \
503: } while (0)
504:
505: /* Return the low n bits of the bit accumulator (n < 16) */
506: #define BITS(n) \
507: ((unsigned)hold & ((1U << (n)) - 1))
508:
509: /* Remove n bits from the bit accumulator */
510: #define DROPBITS(n) \
511: do { \
512: hold >>= (n); \
513: bits -= (unsigned)(n); \
514: } while (0)
515:
516: /* Remove zero to seven bits as needed to go to a byte boundary */
517: #define BYTEBITS() \
518: do { \
519: hold >>= bits & 7; \
520: bits -= bits & 7; \
521: } while (0)
522:
523: /*
524: inflate() uses a state machine to process as much input data and generate as
525: much output data as possible before returning. The state machine is
526: structured roughly as follows:
527:
528: for (;;) switch (state) {
529: ...
530: case STATEn:
531: if (not enough input data or output space to make progress)
532: return;
533: ... make progress ...
534: state = STATEm;
535: break;
536: ...
537: }
538:
539: so when inflate() is called again, the same case is attempted again, and
540: if the appropriate resources are provided, the machine proceeds to the
541: next state. The NEEDBITS() macro is usually the way the state evaluates
542: whether it can proceed or should return. NEEDBITS() does the return if
543: the requested bits are not available. The typical use of the BITS macros
544: is:
545:
546: NEEDBITS(n);
547: ... do something with BITS(n) ...
548: DROPBITS(n);
549:
550: where NEEDBITS(n) either returns from inflate() if there isn't enough
551: input left to load n bits into the accumulator, or it continues. BITS(n)
552: gives the low n bits in the accumulator. When done, DROPBITS(n) drops
553: the low n bits off the accumulator. INITBITS() clears the accumulator
554: and sets the number of available bits to zero. BYTEBITS() discards just
555: enough bits to put the accumulator on a byte boundary. After BYTEBITS()
556: and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
557:
558: NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
559: if there is no input available. The decoding of variable length codes uses
560: PULLBYTE() directly in order to pull just enough bytes to decode the next
561: code, and no more.
562:
563: Some states loop until they get enough input, making sure that enough
564: state information is maintained to continue the loop where it left off
565: if NEEDBITS() returns in the loop. For example, want, need, and keep
566: would all have to actually be part of the saved state in case NEEDBITS()
567: returns:
568:
569: case STATEw:
570: while (want < need) {
571: NEEDBITS(n);
572: keep[want++] = BITS(n);
573: DROPBITS(n);
574: }
575: state = STATEx;
576: case STATEx:
577:
578: As shown above, if the next state is also the next case, then the break
579: is omitted.
580:
581: A state may also return if there is not enough output space available to
582: complete that state. Those states are copying stored data, writing a
583: literal byte, and copying a matching string.
584:
585: When returning, a "goto inf_leave" is used to update the total counters,
586: update the check value, and determine whether any progress has been made
587: during that inflate() call in order to return the proper return code.
588: Progress is defined as a change in either strm->avail_in or strm->avail_out.
589: When there is a window, goto inf_leave will update the window with the last
590: output written. If a goto inf_leave occurs in the middle of decompression
591: and there is no window currently, goto inf_leave will create one and copy
592: output to the window for the next call of inflate().
593:
594: In this implementation, the flush parameter of inflate() only affects the
595: return code (per zlib.h). inflate() always writes as much as possible to
596: strm->next_out, given the space available and the provided input--the effect
597: documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
598: the allocation of and copying into a sliding window until necessary, which
599: provides the effect documented in zlib.h for Z_FINISH when the entire input
600: stream available. So the only thing the flush parameter actually does is:
601: when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
602: will return Z_BUF_ERROR if it has not reached the end of the stream.
603: */
604:
605: int ZEXPORT inflate(strm, flush)
606: z_streamp strm;
607: int flush;
608: {
609: struct inflate_state FAR *state;
610: z_const unsigned char FAR *next; /* next input */
611: unsigned char FAR *put; /* next output */
612: unsigned have, left; /* available input and output */
613: unsigned long hold; /* bit buffer */
614: unsigned bits; /* bits in bit buffer */
615: unsigned in, out; /* save starting available input and output */
616: unsigned copy; /* number of stored or match bytes to copy */
617: unsigned char FAR *from; /* where to copy match bytes from */
618: code here; /* current decoding table entry */
619: code last; /* parent table entry */
620: unsigned len; /* length to copy for repeats, bits to drop */
621: int ret; /* return code */
622: #ifdef GUNZIP
623: unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
624: #endif
625: static const unsigned short order[19] = /* permutation of code lengths */
626: {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
627:
628: if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL ||
629: (strm->next_in == Z_NULL && strm->avail_in != 0))
630: return Z_STREAM_ERROR;
631:
632: state = (struct inflate_state FAR *)strm->state;
633: if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
634: LOAD();
635: in = have;
636: out = left;
637: ret = Z_OK;
638: for (;;)
639: switch (state->mode) {
640: case HEAD:
641: if (state->wrap == 0) {
642: state->mode = TYPEDO;
643: break;
644: }
645: NEEDBITS(16);
646: #ifdef GUNZIP
647: if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
648: state->check = crc32(0L, Z_NULL, 0);
649: CRC2(state->check, hold);
650: INITBITS();
651: state->mode = FLAGS;
652: break;
653: }
654: state->flags = 0; /* expect zlib header */
655: if (state->head != Z_NULL)
656: state->head->done = -1;
657: if (!(state->wrap & 1) || /* check if zlib header allowed */
658: #else
659: if (
660: #endif
661: ((BITS(8) << 8) + (hold >> 8)) % 31) {
662: strm->msg = (char *)"incorrect header check";
663: state->mode = BAD;
664: break;
665: }
666: if (BITS(4) != Z_DEFLATED) {
667: strm->msg = (char *)"unknown compression method";
668: state->mode = BAD;
669: break;
670: }
671: DROPBITS(4);
672: len = BITS(4) + 8;
673: if (state->wbits == 0)
674: state->wbits = len;
675: else if (len > state->wbits) {
676: strm->msg = (char *)"invalid window size";
677: state->mode = BAD;
678: break;
679: }
680: state->dmax = 1U << len;
681: Tracev((stderr, "inflate: zlib header ok\n"));
682: strm->adler = state->check = adler32(0L, Z_NULL, 0);
683: state->mode = hold & 0x200 ? DICTID : TYPE;
684: INITBITS();
685: break;
686: #ifdef GUNZIP
687: case FLAGS:
688: NEEDBITS(16);
689: state->flags = (int)(hold);
690: if ((state->flags & 0xff) != Z_DEFLATED) {
691: strm->msg = (char *)"unknown compression method";
692: state->mode = BAD;
693: break;
694: }
695: if (state->flags & 0xe000) {
696: strm->msg = (char *)"unknown header flags set";
697: state->mode = BAD;
698: break;
699: }
700: if (state->head != Z_NULL)
701: state->head->text = (int)((hold >> 8) & 1);
702: if (state->flags & 0x0200) CRC2(state->check, hold);
703: INITBITS();
704: state->mode = TIME;
705: /* FALL THROUGH */
706: case TIME:
707: NEEDBITS(32);
708: if (state->head != Z_NULL)
709: state->head->time = hold;
710: if (state->flags & 0x0200) CRC4(state->check, hold);
711: INITBITS();
712: state->mode = OS;
713: /* FALL THROUGH */
714: case OS:
715: NEEDBITS(16);
716: if (state->head != Z_NULL) {
717: state->head->xflags = (int)(hold & 0xff);
718: state->head->os = (int)(hold >> 8);
719: }
720: if (state->flags & 0x0200) CRC2(state->check, hold);
721: INITBITS();
722: state->mode = EXLEN;
723: /* FALL THROUGH */
724: case EXLEN:
725: if (state->flags & 0x0400) {
726: NEEDBITS(16);
727: state->length = (unsigned)(hold);
728: if (state->head != Z_NULL)
729: state->head->extra_len = (unsigned)hold;
730: if (state->flags & 0x0200) CRC2(state->check, hold);
731: INITBITS();
732: }
733: else if (state->head != Z_NULL)
734: state->head->extra = Z_NULL;
735: state->mode = EXTRA;
736: /* FALL THROUGH */
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: /* FALL THROUGH */
760: case NAME:
761: if (state->flags & 0x0800) {
762: if (have == 0) goto inf_leave;
763: copy = 0;
764: do {
765: len = (unsigned)(next[copy++]);
766: if (state->head != Z_NULL &&
767: state->head->name != Z_NULL &&
768: state->length < state->head->name_max)
769: state->head->name[state->length++] = len;
770: } while (len && copy < have);
771: if (state->flags & 0x0200)
772: state->check = crc32(state->check, next, copy);
773: have -= copy;
774: next += copy;
775: if (len) goto inf_leave;
776: }
777: else if (state->head != Z_NULL)
778: state->head->name = Z_NULL;
779: state->length = 0;
780: state->mode = COMMENT;
781: /* FALL THROUGH */
782: case COMMENT:
783: if (state->flags & 0x1000) {
784: if (have == 0) goto inf_leave;
785: copy = 0;
786: do {
787: len = (unsigned)(next[copy++]);
788: if (state->head != Z_NULL &&
789: state->head->comment != Z_NULL &&
790: state->length < state->head->comm_max)
791: state->head->comment[state->length++] = len;
792: } while (len && copy < have);
793: if (state->flags & 0x0200)
794: state->check = crc32(state->check, next, copy);
795: have -= copy;
796: next += copy;
797: if (len) goto inf_leave;
798: }
799: else if (state->head != Z_NULL)
800: state->head->comment = Z_NULL;
801: state->mode = HCRC;
802: /* FALL THROUGH */
803: case HCRC:
804: if (state->flags & 0x0200) {
805: NEEDBITS(16);
806: if (hold != (state->check & 0xffff)) {
807: strm->msg = (char *)"header crc mismatch";
808: state->mode = BAD;
809: break;
810: }
811: INITBITS();
812: }
813: if (state->head != Z_NULL) {
814: state->head->hcrc = (int)((state->flags >> 9) & 1);
815: state->head->done = 1;
816: }
817: strm->adler = state->check = crc32(0L, Z_NULL, 0);
818: state->mode = TYPE;
819: break;
820: #endif
821: case DICTID:
822: NEEDBITS(32);
823: strm->adler = state->check = ZSWAP32(hold);
824: INITBITS();
825: state->mode = DICT;
826: /* FALL THROUGH */
827: case DICT:
828: if (state->havedict == 0) {
829: RESTORE();
830: return Z_NEED_DICT;
831: }
832: strm->adler = state->check = adler32(0L, Z_NULL, 0);
833: state->mode = TYPE;
834: /* FALL THROUGH */
835: case TYPE:
836: if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
837: /* FALL THROUGH */
838: case TYPEDO:
839: if (state->last) {
840: BYTEBITS();
841: state->mode = CHECK;
842: break;
843: }
844: NEEDBITS(3);
845: state->last = BITS(1);
846: DROPBITS(1);
847: switch (BITS(2)) {
848: case 0: /* stored block */
849: Tracev((stderr, "inflate: stored block%s\n",
850: state->last ? " (last)" : ""));
851: state->mode = STORED;
852: break;
853: case 1: /* fixed block */
854: fixedtables(state);
855: Tracev((stderr, "inflate: fixed codes block%s\n",
856: state->last ? " (last)" : ""));
857: state->mode = LEN_; /* decode codes */
858: if (flush == Z_TREES) {
859: DROPBITS(2);
860: goto inf_leave;
861: }
862: break;
863: case 2: /* dynamic block */
864: Tracev((stderr, "inflate: dynamic codes block%s\n",
865: state->last ? " (last)" : ""));
866: state->mode = TABLE;
867: break;
868: case 3:
869: strm->msg = (char *)"invalid block type";
870: state->mode = BAD;
871: }
872: DROPBITS(2);
873: break;
874: case STORED:
875: BYTEBITS(); /* go to byte boundary */
876: NEEDBITS(32);
877: if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
878: strm->msg = (char *)"invalid stored block lengths";
879: state->mode = BAD;
880: break;
881: }
882: state->length = (unsigned)hold & 0xffff;
883: Tracev((stderr, "inflate: stored length %u\n",
884: state->length));
885: INITBITS();
886: state->mode = COPY_;
887: if (flush == Z_TREES) goto inf_leave;
888: /* FALLTHROUGH */
889: case COPY_:
890: state->mode = COPY;
891: /* FALLTHROUGH */
892: case COPY:
893: copy = state->length;
894: if (copy) {
895: if (copy > have) copy = have;
896: if (copy > left) copy = left;
897: if (copy == 0) goto inf_leave;
898: zmemcpy(put, next, copy);
899: have -= copy;
900: next += copy;
901: left -= copy;
902: put += copy;
903: state->length -= copy;
904: break;
905: }
906: Tracev((stderr, "inflate: stored end\n"));
907: state->mode = TYPE;
908: break;
909: case TABLE:
910: NEEDBITS(14);
911: state->nlen = BITS(5) + 257;
912: DROPBITS(5);
913: state->ndist = BITS(5) + 1;
914: DROPBITS(5);
915: state->ncode = BITS(4) + 4;
916: DROPBITS(4);
917: #ifndef PKZIP_BUG_WORKAROUND
918: if (state->nlen > 286 || state->ndist > 30) {
919: strm->msg = (char *)"too many length or distance symbols";
920: state->mode = BAD;
921: break;
922: }
923: #endif
924: Tracev((stderr, "inflate: table sizes ok\n"));
925: state->have = 0;
926: state->mode = LENLENS;
927: /* FALL THROUGH */
928: case LENLENS:
929: while (state->have < state->ncode) {
930: NEEDBITS(3);
931: state->lens[order[state->have++]] = (unsigned short)BITS(3);
932: DROPBITS(3);
933: }
934: while (state->have < 19)
935: state->lens[order[state->have++]] = 0;
936: state->next = state->codes;
937: state->lencode = (const code FAR *)(state->next);
938: state->lenbits = 7;
939: ret = inflate_table(CODES, state->lens, 19, &(state->next),
940: &(state->lenbits), state->work);
941: if (ret) {
942: strm->msg = (char *)"invalid code lengths set";
943: state->mode = BAD;
944: break;
945: }
946: Tracev((stderr, "inflate: code lengths ok\n"));
947: state->have = 0;
948: state->mode = CODELENS;
949: /* FALL THROUGH */
950: case CODELENS:
951: while (state->have < state->nlen + state->ndist) {
952: for (;;) {
953: here = state->lencode[BITS(state->lenbits)];
954: if ((unsigned)(here.bits) <= bits) break;
955: PULLBYTE();
956: }
957: if (here.val < 16) {
958: DROPBITS(here.bits);
959: state->lens[state->have++] = here.val;
960: }
961: else {
962: if (here.val == 16) {
963: NEEDBITS(here.bits + 2);
964: DROPBITS(here.bits);
965: if (state->have == 0) {
966: strm->msg = (char *)"invalid bit length repeat";
967: state->mode = BAD;
968: break;
969: }
970: len = state->lens[state->have - 1];
971: copy = 3 + BITS(2);
972: DROPBITS(2);
973: }
974: else if (here.val == 17) {
975: NEEDBITS(here.bits + 3);
976: DROPBITS(here.bits);
977: len = 0;
978: copy = 3 + BITS(3);
979: DROPBITS(3);
980: }
981: else {
982: NEEDBITS(here.bits + 7);
983: DROPBITS(here.bits);
984: len = 0;
985: copy = 11 + BITS(7);
986: DROPBITS(7);
987: }
988: if (state->have + copy > state->nlen + state->ndist) {
989: strm->msg = (char *)"invalid bit length repeat";
990: state->mode = BAD;
991: break;
992: }
993: while (copy--)
994: state->lens[state->have++] = (unsigned short)len;
995: }
996: }
997:
998: /* handle error breaks in while */
999: if (state->mode == BAD) break;
1000:
1001: /* check for end-of-block code (better have one) */
1002: if (state->lens[256] == 0) {
1003: strm->msg = (char *)"invalid code -- missing end-of-block";
1004: state->mode = BAD;
1005: break;
1006: }
1007:
1008: /* build code tables -- note: do not change the lenbits or distbits
1009: values here (9 and 6) without reading the comments in inftrees.h
1010: concerning the ENOUGH constants, which depend on those values */
1011: state->next = state->codes;
1012: state->lencode = (const code FAR *)(state->next);
1013: state->lenbits = 9;
1014: ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1015: &(state->lenbits), state->work);
1016: if (ret) {
1017: strm->msg = (char *)"invalid literal/lengths set";
1018: state->mode = BAD;
1019: break;
1020: }
1021: state->distcode = (const code FAR *)(state->next);
1022: state->distbits = 6;
1023: ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1024: &(state->next), &(state->distbits), state->work);
1025: if (ret) {
1026: strm->msg = (char *)"invalid distances set";
1027: state->mode = BAD;
1028: break;
1029: }
1030: Tracev((stderr, "inflate: codes ok\n"));
1031: state->mode = LEN_;
1032: if (flush == Z_TREES) goto inf_leave;
1033: /* FALL THROUGH */
1034: case LEN_:
1035: state->mode = LEN;
1036: /* FALL THROUGH */
1037: case LEN:
1038: if (have >= 6 && left >= 258) {
1039: RESTORE();
1040: inflate_fast(strm, out);
1041: LOAD();
1042: if (state->mode == TYPE)
1043: state->back = -1;
1044: break;
1045: }
1046: state->back = 0;
1047: for (;;) {
1048: here = state->lencode[BITS(state->lenbits)];
1049: if ((unsigned)(here.bits) <= bits) break;
1050: PULLBYTE();
1051: }
1052: if (here.op && (here.op & 0xf0) == 0) {
1053: last = here;
1054: for (;;) {
1055: here = state->lencode[last.val +
1056: (BITS(last.bits + last.op) >> last.bits)];
1057: if ((unsigned)(last.bits + here.bits) <= bits) break;
1058: PULLBYTE();
1059: }
1060: DROPBITS(last.bits);
1061: state->back += last.bits;
1062: }
1063: DROPBITS(here.bits);
1064: state->back += here.bits;
1065: state->length = (unsigned)here.val;
1066: if ((int)(here.op) == 0) {
1067: Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1068: "inflate: literal '%c'\n" :
1069: "inflate: literal 0x%02x\n", here.val));
1070: state->mode = LIT;
1071: break;
1072: }
1073: if (here.op & 32) {
1074: Tracevv((stderr, "inflate: end of block\n"));
1075: state->back = -1;
1076: state->mode = TYPE;
1077: break;
1078: }
1079: if (here.op & 64) {
1080: strm->msg = (char *)"invalid literal/length code";
1081: state->mode = BAD;
1082: break;
1083: }
1084: state->extra = (unsigned)(here.op) & 15;
1085: state->mode = LENEXT;
1086: /* FALL THROUGH */
1087: case LENEXT:
1088: if (state->extra) {
1089: NEEDBITS(state->extra);
1090: state->length += BITS(state->extra);
1091: DROPBITS(state->extra);
1092: state->back += state->extra;
1093: }
1094: Tracevv((stderr, "inflate: length %u\n", state->length));
1095: state->was = state->length;
1096: state->mode = DIST;
1097: /* FALL THROUGH */
1098: case DIST:
1099: for (;;) {
1100: here = state->distcode[BITS(state->distbits)];
1101: if ((unsigned)(here.bits) <= bits) break;
1102: PULLBYTE();
1103: }
1104: if ((here.op & 0xf0) == 0) {
1105: last = here;
1106: for (;;) {
1107: here = state->distcode[last.val +
1108: (BITS(last.bits + last.op) >> last.bits)];
1109: if ((unsigned)(last.bits + here.bits) <= bits) break;
1110: PULLBYTE();
1111: }
1112: DROPBITS(last.bits);
1113: state->back += last.bits;
1114: }
1115: DROPBITS(here.bits);
1116: state->back += here.bits;
1117: if (here.op & 64) {
1118: strm->msg = (char *)"invalid distance code";
1119: state->mode = BAD;
1120: break;
1121: }
1122: state->offset = (unsigned)here.val;
1123: state->extra = (unsigned)(here.op) & 15;
1124: state->mode = DISTEXT;
1125: /* FALL THROUGH */
1126: case DISTEXT:
1127: if (state->extra) {
1128: NEEDBITS(state->extra);
1129: state->offset += BITS(state->extra);
1130: DROPBITS(state->extra);
1131: state->back += state->extra;
1132: }
1133: #ifdef INFLATE_STRICT
1134: if (state->offset > state->dmax) {
1135: strm->msg = (char *)"invalid distance too far back";
1136: state->mode = BAD;
1137: break;
1138: }
1139: #endif
1140: Tracevv((stderr, "inflate: distance %u\n", state->offset));
1141: state->mode = MATCH;
1142: /* FALL THROUGH */
1143: case MATCH:
1144: if (left == 0) goto inf_leave;
1145: copy = out - left;
1146: if (state->offset > copy) { /* copy from window */
1147: copy = state->offset - copy;
1148: if (copy > state->whave) {
1149: if (state->sane) {
1150: strm->msg = (char *)"invalid distance too far back";
1151: state->mode = BAD;
1152: break;
1153: }
1154: #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1155: Trace((stderr, "inflate.c too far\n"));
1156: copy -= state->whave;
1157: if (copy > state->length) copy = state->length;
1158: if (copy > left) copy = left;
1159: left -= copy;
1160: state->length -= copy;
1161: do {
1162: *put++ = 0;
1163: } while (--copy);
1164: if (state->length == 0) state->mode = LEN;
1165: break;
1166: #endif
1167: }
1168: if (copy > state->wnext) {
1169: copy -= state->wnext;
1170: from = state->window + (state->wsize - copy);
1171: }
1172: else
1173: from = state->window + (state->wnext - copy);
1174: if (copy > state->length) copy = state->length;
1175: }
1176: else { /* copy from output */
1177: from = put - state->offset;
1178: copy = state->length;
1179: }
1180: if (copy > left) copy = left;
1181: left -= copy;
1182: state->length -= copy;
1183: do {
1184: *put++ = *from++;
1185: } while (--copy);
1186: if (state->length == 0) state->mode = LEN;
1187: break;
1188: case LIT:
1189: if (left == 0) goto inf_leave;
1190: *put++ = (unsigned char)(state->length);
1191: left--;
1192: state->mode = LEN;
1193: break;
1194: case CHECK:
1195: if (state->wrap) {
1196: NEEDBITS(32);
1197: out -= left;
1198: strm->total_out += out;
1199: state->total += out;
1200: if (out)
1201: strm->adler = state->check =
1202: UPDATE(state->check, put - out, out);
1203: out = left;
1204: if ((
1205: #ifdef GUNZIP
1206: state->flags ? hold :
1207: #endif
1208: ZSWAP32(hold)) != state->check) {
1209: strm->msg = (char *)"incorrect data check";
1210: state->mode = BAD;
1211: break;
1212: }
1213: INITBITS();
1214: Tracev((stderr, "inflate: check matches trailer\n"));
1215: }
1216: #ifdef GUNZIP
1217: state->mode = LENGTH;
1218: /* FALL THROUGH */
1219: case LENGTH:
1220: if (state->wrap && state->flags) {
1221: NEEDBITS(32);
1222: if (hold != (state->total & 0xffffffffUL)) {
1223: strm->msg = (char *)"incorrect length check";
1224: state->mode = BAD;
1225: break;
1226: }
1227: INITBITS();
1228: Tracev((stderr, "inflate: length matches trailer\n"));
1229: }
1230: #endif
1231: state->mode = DONE;
1232: /* FALL THROUGH */
1233: case DONE:
1234: ret = Z_STREAM_END;
1235: goto inf_leave;
1236: case BAD:
1237: ret = Z_DATA_ERROR;
1238: goto inf_leave;
1239: case MEM:
1240: return Z_MEM_ERROR;
1241: case SYNC:
1242: default:
1243: return Z_STREAM_ERROR;
1244: }
1245:
1246: /*
1247: Return from inflate(), updating the total counts and the check value.
1248: If there was no progress during the inflate() call, return a buffer
1249: error. Call updatewindow() to create and/or update the window state.
1250: Note: a memory error from inflate() is non-recoverable.
1251: */
1252: inf_leave:
1253: RESTORE();
1254: if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
1255: (state->mode < CHECK || flush != Z_FINISH)))
1256: if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
1257: state->mode = MEM;
1258: return Z_MEM_ERROR;
1259: }
1260: in -= strm->avail_in;
1261: out -= strm->avail_out;
1262: strm->total_in += in;
1263: strm->total_out += out;
1264: state->total += out;
1265: if (state->wrap && out)
1266: strm->adler = state->check =
1267: UPDATE(state->check, strm->next_out - out, out);
1268: strm->data_type = state->bits + (state->last ? 64 : 0) +
1269: (state->mode == TYPE ? 128 : 0) +
1270: (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1271: if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1272: ret = Z_BUF_ERROR;
1273: return ret;
1274: }
1275:
1276: int ZEXPORT inflateEnd(strm)
1277: z_streamp strm;
1278: {
1279: struct inflate_state FAR *state;
1280: if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
1281: return Z_STREAM_ERROR;
1282: state = (struct inflate_state FAR *)strm->state;
1283: if (state->window != Z_NULL) ZFREE(strm, state->window);
1284: ZFREE(strm, strm->state);
1285: strm->state = Z_NULL;
1286: Tracev((stderr, "inflate: end\n"));
1287: return Z_OK;
1288: }
1289:
1290: int ZEXPORT inflateGetDictionary(strm, dictionary, dictLength)
1291: z_streamp strm;
1292: Bytef *dictionary;
1293: uInt *dictLength;
1294: {
1295: struct inflate_state FAR *state;
1296:
1297: /* check state */
1298: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1299: state = (struct inflate_state FAR *)strm->state;
1300:
1301: /* copy dictionary */
1302: if (state->whave && dictionary != Z_NULL) {
1303: zmemcpy(dictionary, state->window + state->wnext,
1304: state->whave - state->wnext);
1305: zmemcpy(dictionary + state->whave - state->wnext,
1306: state->window, state->wnext);
1307: }
1308: if (dictLength != Z_NULL)
1309: *dictLength = state->whave;
1310: return Z_OK;
1311: }
1312:
1313: int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
1314: z_streamp strm;
1315: const Bytef *dictionary;
1316: uInt dictLength;
1317: {
1318: struct inflate_state FAR *state;
1319: unsigned long dictid;
1320: int ret;
1321:
1322: /* check state */
1323: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1324: state = (struct inflate_state FAR *)strm->state;
1325: if (state->wrap != 0 && state->mode != DICT)
1326: return Z_STREAM_ERROR;
1327:
1328: /* check for correct dictionary identifier */
1329: if (state->mode == DICT) {
1330: dictid = adler32(0L, Z_NULL, 0);
1331: dictid = adler32(dictid, dictionary, dictLength);
1332: if (dictid != state->check)
1333: return Z_DATA_ERROR;
1334: }
1335:
1336: /* copy dictionary to window using updatewindow(), which will amend the
1337: existing dictionary if appropriate */
1338: ret = updatewindow(strm, dictionary + dictLength, dictLength);
1339: if (ret) {
1340: state->mode = MEM;
1341: return Z_MEM_ERROR;
1342: }
1343: state->havedict = 1;
1344: Tracev((stderr, "inflate: dictionary set\n"));
1345: return Z_OK;
1346: }
1347:
1348: int ZEXPORT inflateGetHeader(strm, head)
1349: z_streamp strm;
1350: gz_headerp head;
1351: {
1352: struct inflate_state FAR *state;
1353:
1354: /* check state */
1355: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1356: state = (struct inflate_state FAR *)strm->state;
1357: if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
1358:
1359: /* save header structure */
1360: state->head = head;
1361: head->done = 0;
1362: return Z_OK;
1363: }
1364:
1365: /*
1366: Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found
1367: or when out of input. When called, *have is the number of pattern bytes
1368: found in order so far, in 0..3. On return *have is updated to the new
1369: state. If on return *have equals four, then the pattern was found and the
1370: return value is how many bytes were read including the last byte of the
1371: pattern. If *have is less than four, then the pattern has not been found
1372: yet and the return value is len. In the latter case, syncsearch() can be
1373: called again with more data and the *have state. *have is initialized to
1374: zero for the first call.
1375: */
1376: local unsigned syncsearch(have, buf, len)
1377: unsigned FAR *have;
1378: const unsigned char FAR *buf;
1379: unsigned len;
1380: {
1381: unsigned got;
1382: unsigned next;
1383:
1384: got = *have;
1385: next = 0;
1386: while (next < len && got < 4) {
1387: if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
1388: got++;
1389: else if (buf[next])
1390: got = 0;
1391: else
1392: got = 4 - got;
1393: next++;
1394: }
1395: *have = got;
1396: return next;
1397: }
1398:
1399: int ZEXPORT inflateSync(strm)
1400: z_streamp strm;
1401: {
1402: unsigned len; /* number of bytes to look at or looked at */
1403: unsigned long in, out; /* temporary to save total_in and total_out */
1404: unsigned char buf[4]; /* to restore bit buffer to byte string */
1405: struct inflate_state FAR *state;
1406:
1407: /* check parameters */
1408: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1409: state = (struct inflate_state FAR *)strm->state;
1410: if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
1411:
1412: /* if first time, start search in bit buffer */
1413: if (state->mode != SYNC) {
1414: state->mode = SYNC;
1415: state->hold <<= state->bits & 7;
1416: state->bits -= state->bits & 7;
1417: len = 0;
1418: while (state->bits >= 8) {
1419: buf[len++] = (unsigned char)(state->hold);
1420: state->hold >>= 8;
1421: state->bits -= 8;
1422: }
1423: state->have = 0;
1424: syncsearch(&(state->have), buf, len);
1425: }
1426:
1427: /* search available input */
1428: len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
1429: strm->avail_in -= len;
1430: strm->next_in += len;
1431: strm->total_in += len;
1432:
1433: /* return no joy or set up to restart inflate() on a new block */
1434: if (state->have != 4) return Z_DATA_ERROR;
1435: in = strm->total_in; out = strm->total_out;
1436: inflateReset(strm);
1437: strm->total_in = in; strm->total_out = out;
1438: state->mode = TYPE;
1439: return Z_OK;
1440: }
1441:
1442: /*
1443: Returns true if inflate is currently at the end of a block generated by
1444: Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
1445: implementation to provide an additional safety check. PPP uses
1446: Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
1447: block. When decompressing, PPP checks that at the end of input packet,
1448: inflate is waiting for these length bytes.
1449: */
1450: int ZEXPORT inflateSyncPoint(strm)
1451: z_streamp strm;
1452: {
1453: struct inflate_state FAR *state;
1454:
1455: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1456: state = (struct inflate_state FAR *)strm->state;
1457: return state->mode == STORED && state->bits == 0;
1458: }
1459:
1460: int ZEXPORT inflateCopy(dest, source)
1461: z_streamp dest;
1462: z_streamp source;
1463: {
1464: struct inflate_state FAR *state;
1465: struct inflate_state FAR *copy;
1466: unsigned char FAR *window;
1467: unsigned wsize;
1468:
1469: /* check input */
1470: if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL ||
1471: source->zalloc == (alloc_func)0 || source->zfree == (free_func)0)
1472: return Z_STREAM_ERROR;
1473: state = (struct inflate_state FAR *)source->state;
1474:
1475: /* allocate space */
1476: copy = (struct inflate_state FAR *)
1477: ZALLOC(source, 1, sizeof(struct inflate_state));
1478: if (copy == Z_NULL) return Z_MEM_ERROR;
1479: window = Z_NULL;
1480: if (state->window != Z_NULL) {
1481: window = (unsigned char FAR *)
1482: ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
1483: if (window == Z_NULL) {
1484: ZFREE(source, copy);
1485: return Z_MEM_ERROR;
1486: }
1487: }
1488:
1489: /* copy state */
1490: zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
1491: zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state));
1492: if (state->lencode >= state->codes &&
1493: state->lencode <= state->codes + ENOUGH - 1) {
1494: copy->lencode = copy->codes + (state->lencode - state->codes);
1495: copy->distcode = copy->codes + (state->distcode - state->codes);
1496: }
1497: copy->next = copy->codes + (state->next - state->codes);
1498: if (window != Z_NULL) {
1499: wsize = 1U << state->wbits;
1500: zmemcpy(window, state->window, wsize);
1501: }
1502: copy->window = window;
1503: dest->state = (struct internal_state FAR *)copy;
1504: return Z_OK;
1505: }
1506:
1507: int ZEXPORT inflateUndermine(strm, subvert)
1508: z_streamp strm;
1509: int subvert;
1510: {
1511: struct inflate_state FAR *state;
1512:
1513: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1514: state = (struct inflate_state FAR *)strm->state;
1515: state->sane = !subvert;
1516: #ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1517: return Z_OK;
1518: #else
1519: state->sane = 1;
1520: return Z_DATA_ERROR;
1521: #endif
1522: }
1523:
1524: long ZEXPORT inflateMark(strm)
1525: z_streamp strm;
1526: {
1527: struct inflate_state FAR *state;
1528:
1529: if (strm == Z_NULL || strm->state == Z_NULL)
1530: return (long)(((unsigned long)0 - 1) << 16);
1531: state = (struct inflate_state FAR *)strm->state;
1532: return (long)(((unsigned long)((long)state->back)) << 16) +
1533: (state->mode == COPY ? state->length :
1534: (state->mode == MATCH ? state->was - state->length : 0));
1535: }
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