Coverage Report

Created: 2025-06-22 06:29

/src/zlib/inflate.c
Line
Count
Source (jump to first uncovered line)
1
/* inflate.c -- zlib decompression
2
 * Copyright (C) 1995-2022 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
248k
local int inflateStateCheck(z_streamp strm) {
95
248k
    struct inflate_state FAR *state;
96
248k
    if (strm == Z_NULL ||
97
248k
        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
98
0
        return 1;
99
248k
    state = (struct inflate_state FAR *)strm->state;
100
248k
    if (state == Z_NULL || state->strm != strm ||
101
248k
        state->mode < HEAD || state->mode > SYNC)
102
0
        return 1;
103
248k
    return 0;
104
248k
}
105
106
18.2k
int ZEXPORT inflateResetKeep(z_streamp strm) {
107
18.2k
    struct inflate_state FAR *state;
108
109
18.2k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
110
18.2k
    state = (struct inflate_state FAR *)strm->state;
111
18.2k
    strm->total_in = strm->total_out = state->total = 0;
112
18.2k
    strm->msg = Z_NULL;
113
18.2k
    if (state->wrap)        /* to support ill-conceived Java test suite */
114
18.2k
        strm->adler = state->wrap & 1;
115
18.2k
    state->mode = HEAD;
116
18.2k
    state->last = 0;
117
18.2k
    state->havedict = 0;
118
18.2k
    state->flags = -1;
119
18.2k
    state->dmax = 32768U;
120
18.2k
    state->head = Z_NULL;
121
18.2k
    state->hold = 0;
122
18.2k
    state->bits = 0;
123
18.2k
    state->lencode = state->distcode = state->next = state->codes;
124
18.2k
    state->sane = 1;
125
18.2k
    state->back = -1;
126
18.2k
    Tracev((stderr, "inflate: reset\n"));
127
18.2k
    return Z_OK;
128
18.2k
}
129
130
18.2k
int ZEXPORT inflateReset(z_streamp strm) {
131
18.2k
    struct inflate_state FAR *state;
132
133
18.2k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
134
18.2k
    state = (struct inflate_state FAR *)strm->state;
135
18.2k
    state->wsize = 0;
136
18.2k
    state->whave = 0;
137
18.2k
    state->wnext = 0;
138
18.2k
    return inflateResetKeep(strm);
139
18.2k
}
140
141
18.2k
int ZEXPORT inflateReset2(z_streamp strm, int windowBits) {
142
18.2k
    int wrap;
143
18.2k
    struct inflate_state FAR *state;
144
145
    /* get the state */
146
18.2k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
147
18.2k
    state = (struct inflate_state FAR *)strm->state;
148
149
    /* extract wrap request from windowBits parameter */
150
18.2k
    if (windowBits < 0) {
151
0
        if (windowBits < -15)
152
0
            return Z_STREAM_ERROR;
153
0
        wrap = 0;
154
0
        windowBits = -windowBits;
155
0
    }
156
18.2k
    else {
157
18.2k
        wrap = (windowBits >> 4) + 5;
158
18.2k
#ifdef GUNZIP
159
18.2k
        if (windowBits < 48)
160
18.2k
            windowBits &= 15;
161
18.2k
#endif
162
18.2k
    }
163
164
    /* set number of window bits, free window if different */
165
18.2k
    if (windowBits && (windowBits < 8 || windowBits > 15))
166
0
        return Z_STREAM_ERROR;
167
18.2k
    if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
168
0
        ZFREE(strm, state->window);
169
0
        state->window = Z_NULL;
170
0
    }
171
172
    /* update state and reset the rest of it */
173
18.2k
    state->wrap = wrap;
174
18.2k
    state->wbits = (unsigned)windowBits;
175
18.2k
    return inflateReset(strm);
176
18.2k
}
177
178
int ZEXPORT inflateInit2_(z_streamp strm, int windowBits,
179
18.2k
                          const char *version, int stream_size) {
180
18.2k
    int ret;
181
18.2k
    struct inflate_state FAR *state;
182
183
18.2k
    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
184
18.2k
        stream_size != (int)(sizeof(z_stream)))
185
0
        return Z_VERSION_ERROR;
186
18.2k
    if (strm == Z_NULL) return Z_STREAM_ERROR;
187
18.2k
    strm->msg = Z_NULL;                 /* in case we return an error */
188
18.2k
    if (strm->zalloc == (alloc_func)0) {
189
#ifdef Z_SOLO
190
        return Z_STREAM_ERROR;
191
#else
192
18.2k
        strm->zalloc = zcalloc;
193
18.2k
        strm->opaque = (voidpf)0;
194
18.2k
#endif
195
18.2k
    }
196
18.2k
    if (strm->zfree == (free_func)0)
197
#ifdef Z_SOLO
198
        return Z_STREAM_ERROR;
199
#else
200
18.2k
        strm->zfree = zcfree;
201
18.2k
#endif
202
18.2k
    state = (struct inflate_state FAR *)
203
18.2k
            ZALLOC(strm, 1, sizeof(struct inflate_state));
204
18.2k
    if (state == Z_NULL) return Z_MEM_ERROR;
205
18.2k
    Tracev((stderr, "inflate: allocated\n"));
206
18.2k
    strm->state = (struct internal_state FAR *)state;
207
18.2k
    state->strm = strm;
208
18.2k
    state->window = Z_NULL;
209
18.2k
    state->mode = HEAD;     /* to pass state test in inflateReset2() */
210
18.2k
    ret = inflateReset2(strm, windowBits);
211
18.2k
    if (ret != Z_OK) {
212
0
        ZFREE(strm, state);
213
0
        strm->state = Z_NULL;
214
0
    }
215
18.2k
    return ret;
216
18.2k
}
217
218
int ZEXPORT inflateInit_(z_streamp strm, const char *version,
219
18.2k
                         int stream_size) {
220
18.2k
    return inflateInit2_(strm, DEF_WBITS, version, stream_size);
221
18.2k
}
222
223
0
int ZEXPORT inflatePrime(z_streamp strm, int bits, int value) {
224
0
    struct inflate_state FAR *state;
225
226
0
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
227
0
    if (bits == 0)
228
0
        return Z_OK;
229
0
    state = (struct inflate_state FAR *)strm->state;
230
0
    if (bits < 0) {
231
0
        state->hold = 0;
232
0
        state->bits = 0;
233
0
        return Z_OK;
234
0
    }
235
0
    if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR;
236
0
    value &= (1L << bits) - 1;
237
0
    state->hold += (unsigned)value << state->bits;
238
0
    state->bits += (uInt)bits;
239
0
    return Z_OK;
240
0
}
241
242
/*
243
   Return state with length and distance decoding tables and index sizes set to
244
   fixed code decoding.  Normally this returns fixed tables from inffixed.h.
245
   If BUILDFIXED is defined, then instead this routine builds the tables the
246
   first time it's called, and returns those tables the first time and
247
   thereafter.  This reduces the size of the code by about 2K bytes, in
248
   exchange for a little execution time.  However, BUILDFIXED should not be
249
   used for threaded applications, since the rewriting of the tables and virgin
250
   may not be thread-safe.
251
 */
252
14.2k
local void fixedtables(struct inflate_state FAR *state) {
253
#ifdef BUILDFIXED
254
    static int virgin = 1;
255
    static code *lenfix, *distfix;
256
    static code fixed[544];
257
258
    /* build fixed huffman tables if first call (may not be thread safe) */
259
    if (virgin) {
260
        unsigned sym, bits;
261
        static code *next;
262
263
        /* literal/length table */
264
        sym = 0;
265
        while (sym < 144) state->lens[sym++] = 8;
266
        while (sym < 256) state->lens[sym++] = 9;
267
        while (sym < 280) state->lens[sym++] = 7;
268
        while (sym < 288) state->lens[sym++] = 8;
269
        next = fixed;
270
        lenfix = next;
271
        bits = 9;
272
        inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
273
274
        /* distance table */
275
        sym = 0;
276
        while (sym < 32) state->lens[sym++] = 5;
277
        distfix = next;
278
        bits = 5;
279
        inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
280
281
        /* do this just once */
282
        virgin = 0;
283
    }
284
#else /* !BUILDFIXED */
285
14.2k
#   include "inffixed.h"
286
14.2k
#endif /* BUILDFIXED */
287
14.2k
    state->lencode = lenfix;
288
14.2k
    state->lenbits = 9;
289
14.2k
    state->distcode = distfix;
290
14.2k
    state->distbits = 5;
291
14.2k
}
292
293
#ifdef MAKEFIXED
294
#include <stdio.h>
295
296
/*
297
   Write out the inffixed.h that is #include'd above.  Defining MAKEFIXED also
298
   defines BUILDFIXED, so the tables are built on the fly.  makefixed() writes
299
   those tables to stdout, which would be piped to inffixed.h.  A small program
300
   can simply call makefixed to do this:
301
302
    void makefixed(void);
303
304
    int main(void)
305
    {
306
        makefixed();
307
        return 0;
308
    }
309
310
   Then that can be linked with zlib built with MAKEFIXED defined and run:
311
312
    a.out > inffixed.h
313
 */
314
void makefixed(void)
315
{
316
    unsigned low, size;
317
    struct inflate_state state;
318
319
    fixedtables(&state);
320
    puts("    /* inffixed.h -- table for decoding fixed codes");
321
    puts("     * Generated automatically by makefixed().");
322
    puts("     */");
323
    puts("");
324
    puts("    /* WARNING: this file should *not* be used by applications.");
325
    puts("       It is part of the implementation of this library and is");
326
    puts("       subject to change. Applications should only use zlib.h.");
327
    puts("     */");
328
    puts("");
329
    size = 1U << 9;
330
    printf("    static const code lenfix[%u] = {", size);
331
    low = 0;
332
    for (;;) {
333
        if ((low % 7) == 0) printf("\n        ");
334
        printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op,
335
               state.lencode[low].bits, state.lencode[low].val);
336
        if (++low == size) break;
337
        putchar(',');
338
    }
339
    puts("\n    };");
340
    size = 1U << 5;
341
    printf("\n    static const code distfix[%u] = {", size);
342
    low = 0;
343
    for (;;) {
344
        if ((low % 6) == 0) printf("\n        ");
345
        printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
346
               state.distcode[low].val);
347
        if (++low == size) break;
348
        putchar(',');
349
    }
350
    puts("\n    };");
351
}
352
#endif /* MAKEFIXED */
353
354
/*
355
   Update the window with the last wsize (normally 32K) bytes written before
356
   returning.  If window does not exist yet, create it.  This is only called
357
   when a window is already in use, or when output has been written during this
358
   inflate call, but the end of the deflate stream has not been reached yet.
359
   It is also called to create a window for dictionary data when a dictionary
360
   is loaded.
361
362
   Providing output buffers larger than 32K to inflate() should provide a speed
363
   advantage, since only the last 32K of output is copied to the sliding window
364
   upon return from inflate(), and since all distances after the first 32K of
365
   output will fall in the output data, making match copies simpler and faster.
366
   The advantage may be dependent on the size of the processor's data caches.
367
 */
368
139k
local int updatewindow(z_streamp strm, const Bytef *end, unsigned copy) {
369
139k
    struct inflate_state FAR *state;
370
139k
    unsigned dist;
371
372
139k
    state = (struct inflate_state FAR *)strm->state;
373
374
    /* if it hasn't been done already, allocate space for the window */
375
139k
    if (state->window == Z_NULL) {
376
3.46k
        state->window = (unsigned char FAR *)
377
3.46k
                        ZALLOC(strm, 1U << state->wbits,
378
3.46k
                               sizeof(unsigned char));
379
3.46k
        if (state->window == Z_NULL) return 1;
380
3.46k
    }
381
382
    /* if window not in use yet, initialize */
383
139k
    if (state->wsize == 0) {
384
3.46k
        state->wsize = 1U << state->wbits;
385
3.46k
        state->wnext = 0;
386
3.46k
        state->whave = 0;
387
3.46k
    }
388
389
    /* copy state->wsize or less output bytes into the circular window */
390
139k
    if (copy >= state->wsize) {
391
686
        zmemcpy(state->window, end - state->wsize, state->wsize);
392
686
        state->wnext = 0;
393
686
        state->whave = state->wsize;
394
686
    }
395
138k
    else {
396
138k
        dist = state->wsize - state->wnext;
397
138k
        if (dist > copy) dist = copy;
398
138k
        zmemcpy(state->window + state->wnext, end - copy, dist);
399
138k
        copy -= dist;
400
138k
        if (copy) {
401
304
            zmemcpy(state->window, end - copy, copy);
402
304
            state->wnext = copy;
403
304
            state->whave = state->wsize;
404
304
        }
405
138k
        else {
406
138k
            state->wnext += dist;
407
138k
            if (state->wnext == state->wsize) state->wnext = 0;
408
138k
            if (state->whave < state->wsize) state->whave += dist;
409
138k
        }
410
138k
    }
411
139k
    return 0;
412
139k
}
413
414
/* Macros for inflate(): */
415
416
/* check function to use adler32() for zlib or crc32() for gzip */
417
#ifdef GUNZIP
418
#  define UPDATE_CHECK(check, buf, len) \
419
133k
    (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
420
#else
421
#  define UPDATE_CHECK(check, buf, len) adler32(check, buf, len)
422
#endif
423
424
/* check macros for header crc */
425
#ifdef GUNZIP
426
#  define CRC2(check, word) \
427
0
    do { \
428
0
        hbuf[0] = (unsigned char)(word); \
429
0
        hbuf[1] = (unsigned char)((word) >> 8); \
430
0
        check = crc32(check, hbuf, 2); \
431
0
    } while (0)
432
433
#  define CRC4(check, word) \
434
0
    do { \
435
0
        hbuf[0] = (unsigned char)(word); \
436
0
        hbuf[1] = (unsigned char)((word) >> 8); \
437
0
        hbuf[2] = (unsigned char)((word) >> 16); \
438
0
        hbuf[3] = (unsigned char)((word) >> 24); \
439
0
        check = crc32(check, hbuf, 4); \
440
0
    } while (0)
441
#endif
442
443
/* Load registers with state in inflate() for speed */
444
#define LOAD() \
445
236k
    do { \
446
236k
        put = strm->next_out; \
447
236k
        left = strm->avail_out; \
448
236k
        next = strm->next_in; \
449
236k
        have = strm->avail_in; \
450
236k
        hold = state->hold; \
451
236k
        bits = state->bits; \
452
236k
    } while (0)
453
454
/* Restore state from registers in inflate() */
455
#define RESTORE() \
456
236k
    do { \
457
236k
        strm->next_out = put; \
458
236k
        strm->avail_out = left; \
459
236k
        strm->next_in = next; \
460
236k
        strm->avail_in = have; \
461
236k
        state->hold = hold; \
462
236k
        state->bits = bits; \
463
236k
    } while (0)
464
465
/* Clear the input bit accumulator */
466
#define INITBITS() \
467
28.7k
    do { \
468
28.7k
        hold = 0; \
469
28.7k
        bits = 0; \
470
28.7k
    } while (0)
471
472
/* Get a byte of input into the bit accumulator, or return from inflate()
473
   if there is no input available. */
474
#define PULLBYTE() \
475
1.25M
    do { \
476
1.25M
        if (have == 0) goto inf_leave; \
477
1.25M
        have--; \
478
1.11M
        hold += (unsigned long)(*next++) << bits; \
479
1.11M
        bits += 8; \
480
1.11M
    } while (0)
481
482
/* Assure that there are at least n bits in the bit accumulator.  If there is
483
   not enough available input to do that, then return from inflate(). */
484
#define NEEDBITS(n) \
485
578k
    do { \
486
946k
        while (bits < (unsigned)(n)) \
487
578k
            PULLBYTE(); \
488
578k
    } while (0)
489
490
/* Return the low n bits of the bit accumulator (n < 16) */
491
#define BITS(n) \
492
3.19M
    ((unsigned)hold & ((1U << (n)) - 1))
493
494
/* Remove n bits from the bit accumulator */
495
#define DROPBITS(n) \
496
2.29M
    do { \
497
2.29M
        hold >>= (n); \
498
2.29M
        bits -= (unsigned)(n); \
499
2.29M
    } while (0)
500
501
/* Remove zero to seven bits as needed to go to a byte boundary */
502
#define BYTEBITS() \
503
13.3k
    do { \
504
13.3k
        hold >>= bits & 7; \
505
13.3k
        bits -= bits & 7; \
506
13.3k
    } while (0)
507
508
/*
509
   inflate() uses a state machine to process as much input data and generate as
510
   much output data as possible before returning.  The state machine is
511
   structured roughly as follows:
512
513
    for (;;) switch (state) {
514
    ...
515
    case STATEn:
516
        if (not enough input data or output space to make progress)
517
            return;
518
        ... make progress ...
519
        state = STATEm;
520
        break;
521
    ...
522
    }
523
524
   so when inflate() is called again, the same case is attempted again, and
525
   if the appropriate resources are provided, the machine proceeds to the
526
   next state.  The NEEDBITS() macro is usually the way the state evaluates
527
   whether it can proceed or should return.  NEEDBITS() does the return if
528
   the requested bits are not available.  The typical use of the BITS macros
529
   is:
530
531
        NEEDBITS(n);
532
        ... do something with BITS(n) ...
533
        DROPBITS(n);
534
535
   where NEEDBITS(n) either returns from inflate() if there isn't enough
536
   input left to load n bits into the accumulator, or it continues.  BITS(n)
537
   gives the low n bits in the accumulator.  When done, DROPBITS(n) drops
538
   the low n bits off the accumulator.  INITBITS() clears the accumulator
539
   and sets the number of available bits to zero.  BYTEBITS() discards just
540
   enough bits to put the accumulator on a byte boundary.  After BYTEBITS()
541
   and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
542
543
   NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
544
   if there is no input available.  The decoding of variable length codes uses
545
   PULLBYTE() directly in order to pull just enough bytes to decode the next
546
   code, and no more.
547
548
   Some states loop until they get enough input, making sure that enough
549
   state information is maintained to continue the loop where it left off
550
   if NEEDBITS() returns in the loop.  For example, want, need, and keep
551
   would all have to actually be part of the saved state in case NEEDBITS()
552
   returns:
553
554
    case STATEw:
555
        while (want < need) {
556
            NEEDBITS(n);
557
            keep[want++] = BITS(n);
558
            DROPBITS(n);
559
        }
560
        state = STATEx;
561
    case STATEx:
562
563
   As shown above, if the next state is also the next case, then the break
564
   is omitted.
565
566
   A state may also return if there is not enough output space available to
567
   complete that state.  Those states are copying stored data, writing a
568
   literal byte, and copying a matching string.
569
570
   When returning, a "goto inf_leave" is used to update the total counters,
571
   update the check value, and determine whether any progress has been made
572
   during that inflate() call in order to return the proper return code.
573
   Progress is defined as a change in either strm->avail_in or strm->avail_out.
574
   When there is a window, goto inf_leave will update the window with the last
575
   output written.  If a goto inf_leave occurs in the middle of decompression
576
   and there is no window currently, goto inf_leave will create one and copy
577
   output to the window for the next call of inflate().
578
579
   In this implementation, the flush parameter of inflate() only affects the
580
   return code (per zlib.h).  inflate() always writes as much as possible to
581
   strm->next_out, given the space available and the provided input--the effect
582
   documented in zlib.h of Z_SYNC_FLUSH.  Furthermore, inflate() always defers
583
   the allocation of and copying into a sliding window until necessary, which
584
   provides the effect documented in zlib.h for Z_FINISH when the entire input
585
   stream available.  So the only thing the flush parameter actually does is:
586
   when flush is set to Z_FINISH, inflate() cannot return Z_OK.  Instead it
587
   will return Z_BUF_ERROR if it has not reached the end of the stream.
588
 */
589
590
175k
int ZEXPORT inflate(z_streamp strm, int flush) {
591
175k
    struct inflate_state FAR *state;
592
175k
    z_const unsigned char FAR *next;    /* next input */
593
175k
    unsigned char FAR *put;     /* next output */
594
175k
    unsigned have, left;        /* available input and output */
595
175k
    unsigned long hold;         /* bit buffer */
596
175k
    unsigned bits;              /* bits in bit buffer */
597
175k
    unsigned in, out;           /* save starting available input and output */
598
175k
    unsigned copy;              /* number of stored or match bytes to copy */
599
175k
    unsigned char FAR *from;    /* where to copy match bytes from */
600
175k
    code here;                  /* current decoding table entry */
601
175k
    code last;                  /* parent table entry */
602
175k
    unsigned len;               /* length to copy for repeats, bits to drop */
603
175k
    int ret;                    /* return code */
604
175k
#ifdef GUNZIP
605
175k
    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
606
175k
#endif
607
175k
    static const unsigned short order[19] = /* permutation of code lengths */
608
175k
        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
609
610
175k
    if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
611
175k
        (strm->next_in == Z_NULL && strm->avail_in != 0))
612
0
        return Z_STREAM_ERROR;
613
614
175k
    state = (struct inflate_state FAR *)strm->state;
615
175k
    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
616
175k
    LOAD();
617
175k
    in = have;
618
175k
    out = left;
619
175k
    ret = Z_OK;
620
175k
    for (;;)
621
835k
        switch (state->mode) {
622
18.2k
        case HEAD:
623
18.2k
            if (state->wrap == 0) {
624
0
                state->mode = TYPEDO;
625
0
                break;
626
0
            }
627
18.2k
            NEEDBITS(16);
628
18.1k
#ifdef GUNZIP
629
18.1k
            if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
630
0
                if (state->wbits == 0)
631
0
                    state->wbits = 15;
632
0
                state->check = crc32(0L, Z_NULL, 0);
633
0
                CRC2(state->check, hold);
634
0
                INITBITS();
635
0
                state->mode = FLAGS;
636
0
                break;
637
0
            }
638
18.1k
            if (state->head != Z_NULL)
639
0
                state->head->done = -1;
640
18.1k
            if (!(state->wrap & 1) ||   /* check if zlib header allowed */
641
#else
642
            if (
643
#endif
644
18.1k
                ((BITS(8) << 8) + (hold >> 8)) % 31) {
645
934
                strm->msg = (z_const char *)"incorrect header check";
646
934
                state->mode = BAD;
647
934
                break;
648
934
            }
649
17.2k
            if (BITS(4) != Z_DEFLATED) {
650
53
                strm->msg = (z_const char *)"unknown compression method";
651
53
                state->mode = BAD;
652
53
                break;
653
53
            }
654
17.1k
            DROPBITS(4);
655
17.1k
            len = BITS(4) + 8;
656
17.1k
            if (state->wbits == 0)
657
0
                state->wbits = len;
658
17.1k
            if (len > 15 || len > state->wbits) {
659
5
                strm->msg = (z_const char *)"invalid window size";
660
5
                state->mode = BAD;
661
5
                break;
662
5
            }
663
17.1k
            state->dmax = 1U << len;
664
17.1k
            state->flags = 0;               /* indicate zlib header */
665
17.1k
            Tracev((stderr, "inflate:   zlib header ok\n"));
666
17.1k
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
667
17.1k
            state->mode = hold & 0x200 ? DICTID : TYPE;
668
17.1k
            INITBITS();
669
17.1k
            break;
670
0
#ifdef GUNZIP
671
0
        case FLAGS:
672
0
            NEEDBITS(16);
673
0
            state->flags = (int)(hold);
674
0
            if ((state->flags & 0xff) != Z_DEFLATED) {
675
0
                strm->msg = (z_const char *)"unknown compression method";
676
0
                state->mode = BAD;
677
0
                break;
678
0
            }
679
0
            if (state->flags & 0xe000) {
680
0
                strm->msg = (z_const char *)"unknown header flags set";
681
0
                state->mode = BAD;
682
0
                break;
683
0
            }
684
0
            if (state->head != Z_NULL)
685
0
                state->head->text = (int)((hold >> 8) & 1);
686
0
            if ((state->flags & 0x0200) && (state->wrap & 4))
687
0
                CRC2(state->check, hold);
688
0
            INITBITS();
689
0
            state->mode = TIME;
690
                /* fallthrough */
691
0
        case TIME:
692
0
            NEEDBITS(32);
693
0
            if (state->head != Z_NULL)
694
0
                state->head->time = hold;
695
0
            if ((state->flags & 0x0200) && (state->wrap & 4))
696
0
                CRC4(state->check, hold);
697
0
            INITBITS();
698
0
            state->mode = OS;
699
                /* fallthrough */
700
0
        case OS:
701
0
            NEEDBITS(16);
702
0
            if (state->head != Z_NULL) {
703
0
                state->head->xflags = (int)(hold & 0xff);
704
0
                state->head->os = (int)(hold >> 8);
705
0
            }
706
0
            if ((state->flags & 0x0200) && (state->wrap & 4))
707
0
                CRC2(state->check, hold);
708
0
            INITBITS();
709
0
            state->mode = EXLEN;
710
                /* fallthrough */
711
0
        case EXLEN:
712
0
            if (state->flags & 0x0400) {
713
0
                NEEDBITS(16);
714
0
                state->length = (unsigned)(hold);
715
0
                if (state->head != Z_NULL)
716
0
                    state->head->extra_len = (unsigned)hold;
717
0
                if ((state->flags & 0x0200) && (state->wrap & 4))
718
0
                    CRC2(state->check, hold);
719
0
                INITBITS();
720
0
            }
721
0
            else if (state->head != Z_NULL)
722
0
                state->head->extra = Z_NULL;
723
0
            state->mode = EXTRA;
724
                /* fallthrough */
725
0
        case EXTRA:
726
0
            if (state->flags & 0x0400) {
727
0
                copy = state->length;
728
0
                if (copy > have) copy = have;
729
0
                if (copy) {
730
0
                    if (state->head != Z_NULL &&
731
0
                        state->head->extra != Z_NULL &&
732
0
                        (len = state->head->extra_len - state->length) <
733
0
                            state->head->extra_max) {
734
0
                        zmemcpy(state->head->extra + len, next,
735
0
                                len + copy > state->head->extra_max ?
736
0
                                state->head->extra_max - len : copy);
737
0
                    }
738
0
                    if ((state->flags & 0x0200) && (state->wrap & 4))
739
0
                        state->check = crc32(state->check, next, copy);
740
0
                    have -= copy;
741
0
                    next += copy;
742
0
                    state->length -= copy;
743
0
                }
744
0
                if (state->length) goto inf_leave;
745
0
            }
746
0
            state->length = 0;
747
0
            state->mode = NAME;
748
                /* fallthrough */
749
0
        case NAME:
750
0
            if (state->flags & 0x0800) {
751
0
                if (have == 0) goto inf_leave;
752
0
                copy = 0;
753
0
                do {
754
0
                    len = (unsigned)(next[copy++]);
755
0
                    if (state->head != Z_NULL &&
756
0
                            state->head->name != Z_NULL &&
757
0
                            state->length < state->head->name_max)
758
0
                        state->head->name[state->length++] = (Bytef)len;
759
0
                } while (len && copy < have);
760
0
                if ((state->flags & 0x0200) && (state->wrap & 4))
761
0
                    state->check = crc32(state->check, next, copy);
762
0
                have -= copy;
763
0
                next += copy;
764
0
                if (len) goto inf_leave;
765
0
            }
766
0
            else if (state->head != Z_NULL)
767
0
                state->head->name = Z_NULL;
768
0
            state->length = 0;
769
0
            state->mode = COMMENT;
770
                /* fallthrough */
771
0
        case COMMENT:
772
0
            if (state->flags & 0x1000) {
773
0
                if (have == 0) goto inf_leave;
774
0
                copy = 0;
775
0
                do {
776
0
                    len = (unsigned)(next[copy++]);
777
0
                    if (state->head != Z_NULL &&
778
0
                            state->head->comment != Z_NULL &&
779
0
                            state->length < state->head->comm_max)
780
0
                        state->head->comment[state->length++] = (Bytef)len;
781
0
                } while (len && copy < have);
782
0
                if ((state->flags & 0x0200) && (state->wrap & 4))
783
0
                    state->check = crc32(state->check, next, copy);
784
0
                have -= copy;
785
0
                next += copy;
786
0
                if (len) goto inf_leave;
787
0
            }
788
0
            else if (state->head != Z_NULL)
789
0
                state->head->comment = Z_NULL;
790
0
            state->mode = HCRC;
791
                /* fallthrough */
792
0
        case HCRC:
793
0
            if (state->flags & 0x0200) {
794
0
                NEEDBITS(16);
795
0
                if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
796
0
                    strm->msg = (z_const char *)"header crc mismatch";
797
0
                    state->mode = BAD;
798
0
                    break;
799
0
                }
800
0
                INITBITS();
801
0
            }
802
0
            if (state->head != Z_NULL) {
803
0
                state->head->hcrc = (int)((state->flags >> 9) & 1);
804
0
                state->head->done = 1;
805
0
            }
806
0
            strm->adler = state->check = crc32(0L, Z_NULL, 0);
807
0
            state->mode = TYPE;
808
0
            break;
809
0
#endif
810
21
        case DICTID:
811
21
            NEEDBITS(32);
812
6
            strm->adler = state->check = ZSWAP32(hold);
813
6
            INITBITS();
814
6
            state->mode = DICT;
815
                /* fallthrough */
816
11
        case DICT:
817
11
            if (state->havedict == 0) {
818
11
                RESTORE();
819
11
                return Z_NEED_DICT;
820
11
            }
821
0
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
822
0
            state->mode = TYPE;
823
                /* fallthrough */
824
40.9k
        case TYPE:
825
40.9k
            if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
826
                /* fallthrough */
827
41.1k
        case TYPEDO:
828
41.1k
            if (state->last) {
829
12.0k
                BYTEBITS();
830
12.0k
                state->mode = CHECK;
831
12.0k
                break;
832
12.0k
            }
833
29.0k
            NEEDBITS(3);
834
28.8k
            state->last = BITS(1);
835
28.8k
            DROPBITS(1);
836
28.8k
            switch (BITS(2)) {
837
1.29k
            case 0:                             /* stored block */
838
1.29k
                Tracev((stderr, "inflate:     stored block%s\n",
839
1.29k
                        state->last ? " (last)" : ""));
840
1.29k
                state->mode = STORED;
841
1.29k
                break;
842
14.2k
            case 1:                             /* fixed block */
843
14.2k
                fixedtables(state);
844
14.2k
                Tracev((stderr, "inflate:     fixed codes block%s\n",
845
14.2k
                        state->last ? " (last)" : ""));
846
14.2k
                state->mode = LEN_;             /* decode codes */
847
14.2k
                if (flush == Z_TREES) {
848
0
                    DROPBITS(2);
849
0
                    goto inf_leave;
850
0
                }
851
14.2k
                break;
852
14.2k
            case 2:                             /* dynamic block */
853
13.3k
                Tracev((stderr, "inflate:     dynamic codes block%s\n",
854
13.3k
                        state->last ? " (last)" : ""));
855
13.3k
                state->mode = TABLE;
856
13.3k
                break;
857
48
            case 3:
858
48
                strm->msg = (z_const char *)"invalid block type";
859
48
                state->mode = BAD;
860
28.8k
            }
861
28.8k
            DROPBITS(2);
862
28.8k
            break;
863
1.32k
        case STORED:
864
1.32k
            BYTEBITS();                         /* go to byte boundary */
865
1.32k
            NEEDBITS(32);
866
1.26k
            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
867
111
                strm->msg = (z_const char *)"invalid stored block lengths";
868
111
                state->mode = BAD;
869
111
                break;
870
111
            }
871
1.15k
            state->length = (unsigned)hold & 0xffff;
872
1.15k
            Tracev((stderr, "inflate:       stored length %u\n",
873
1.15k
                    state->length));
874
1.15k
            INITBITS();
875
1.15k
            state->mode = COPY_;
876
1.15k
            if (flush == Z_TREES) goto inf_leave;
877
                /* fallthrough */
878
1.15k
        case COPY_:
879
1.15k
            state->mode = COPY;
880
                /* fallthrough */
881
1.31k
        case COPY:
882
1.31k
            copy = state->length;
883
1.31k
            if (copy) {
884
193
                if (copy > have) copy = have;
885
193
                if (copy > left) copy = left;
886
193
                if (copy == 0) goto inf_leave;
887
110
                zmemcpy(put, next, copy);
888
110
                have -= copy;
889
110
                next += copy;
890
110
                left -= copy;
891
110
                put += copy;
892
110
                state->length -= copy;
893
110
                break;
894
193
            }
895
1.11k
            Tracev((stderr, "inflate:       stored end\n"));
896
1.11k
            state->mode = TYPE;
897
1.11k
            break;
898
14.0k
        case TABLE:
899
14.0k
            NEEDBITS(14);
900
13.2k
            state->nlen = BITS(5) + 257;
901
13.2k
            DROPBITS(5);
902
13.2k
            state->ndist = BITS(5) + 1;
903
13.2k
            DROPBITS(5);
904
13.2k
            state->ncode = BITS(4) + 4;
905
13.2k
            DROPBITS(4);
906
13.2k
#ifndef PKZIP_BUG_WORKAROUND
907
13.2k
            if (state->nlen > 286 || state->ndist > 30) {
908
9
                strm->msg = (z_const char *)"too many length or distance symbols";
909
9
                state->mode = BAD;
910
9
                break;
911
9
            }
912
13.2k
#endif
913
13.2k
            Tracev((stderr, "inflate:       table sizes ok\n"));
914
13.2k
            state->have = 0;
915
13.2k
            state->mode = LENLENS;
916
                /* fallthrough */
917
14.0k
        case LENLENS:
918
231k
            while (state->have < state->ncode) {
919
217k
                NEEDBITS(3);
920
216k
                state->lens[order[state->have++]] = (unsigned short)BITS(3);
921
216k
                DROPBITS(3);
922
216k
            }
923
47.9k
            while (state->have < 19)
924
34.7k
                state->lens[order[state->have++]] = 0;
925
13.2k
            state->next = state->codes;
926
13.2k
            state->lencode = state->distcode = (const code FAR *)(state->next);
927
13.2k
            state->lenbits = 7;
928
13.2k
            ret = inflate_table(CODES, state->lens, 19, &(state->next),
929
13.2k
                                &(state->lenbits), state->work);
930
13.2k
            if (ret) {
931
218
                strm->msg = (z_const char *)"invalid code lengths set";
932
218
                state->mode = BAD;
933
218
                break;
934
218
            }
935
13.0k
            Tracev((stderr, "inflate:       code lengths ok\n"));
936
13.0k
            state->have = 0;
937
13.0k
            state->mode = CODELENS;
938
                /* fallthrough */
939
18.3k
        case CODELENS:
940
1.19M
            while (state->have < state->nlen + state->ndist) {
941
1.63M
                for (;;) {
942
1.63M
                    here = state->lencode[BITS(state->lenbits)];
943
1.63M
                    if ((unsigned)(here.bits) <= bits) break;
944
446k
                    PULLBYTE();
945
446k
                }
946
1.18M
                if (here.val < 16) {
947
1.04M
                    DROPBITS(here.bits);
948
1.04M
                    state->lens[state->have++] = here.val;
949
1.04M
                }
950
143k
                else {
951
143k
                    if (here.val == 16) {
952
39.9k
                        NEEDBITS(here.bits + 2);
953
39.7k
                        DROPBITS(here.bits);
954
39.7k
                        if (state->have == 0) {
955
7
                            strm->msg = (z_const char *)"invalid bit length repeat";
956
7
                            state->mode = BAD;
957
7
                            break;
958
7
                        }
959
39.7k
                        len = state->lens[state->have - 1];
960
39.7k
                        copy = 3 + BITS(2);
961
39.7k
                        DROPBITS(2);
962
39.7k
                    }
963
103k
                    else if (here.val == 17) {
964
61.2k
                        NEEDBITS(here.bits + 3);
965
61.1k
                        DROPBITS(here.bits);
966
61.1k
                        len = 0;
967
61.1k
                        copy = 3 + BITS(3);
968
61.1k
                        DROPBITS(3);
969
61.1k
                    }
970
41.9k
                    else {
971
41.9k
                        NEEDBITS(here.bits + 7);
972
40.7k
                        DROPBITS(here.bits);
973
40.7k
                        len = 0;
974
40.7k
                        copy = 11 + BITS(7);
975
40.7k
                        DROPBITS(7);
976
40.7k
                    }
977
141k
                    if (state->have + copy > state->nlen + state->ndist) {
978
243
                        strm->msg = (z_const char *)"invalid bit length repeat";
979
243
                        state->mode = BAD;
980
243
                        break;
981
243
                    }
982
2.93M
                    while (copy--)
983
2.78M
                        state->lens[state->have++] = (unsigned short)len;
984
141k
                }
985
1.18M
            }
986
987
            /* handle error breaks in while */
988
12.9k
            if (state->mode == BAD) break;
989
990
            /* check for end-of-block code (better have one) */
991
12.6k
            if (state->lens[256] == 0) {
992
55
                strm->msg = (z_const char *)"invalid code -- missing end-of-block";
993
55
                state->mode = BAD;
994
55
                break;
995
55
            }
996
997
            /* build code tables -- note: do not change the lenbits or distbits
998
               values here (9 and 6) without reading the comments in inftrees.h
999
               concerning the ENOUGH constants, which depend on those values */
1000
12.5k
            state->next = state->codes;
1001
12.5k
            state->lencode = (const code FAR *)(state->next);
1002
12.5k
            state->lenbits = 9;
1003
12.5k
            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1004
12.5k
                                &(state->lenbits), state->work);
1005
12.5k
            if (ret) {
1006
132
                strm->msg = (z_const char *)"invalid literal/lengths set";
1007
132
                state->mode = BAD;
1008
132
                break;
1009
132
            }
1010
12.4k
            state->distcode = (const code FAR *)(state->next);
1011
12.4k
            state->distbits = 6;
1012
12.4k
            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1013
12.4k
                            &(state->next), &(state->distbits), state->work);
1014
12.4k
            if (ret) {
1015
75
                strm->msg = (z_const char *)"invalid distances set";
1016
75
                state->mode = BAD;
1017
75
                break;
1018
75
            }
1019
12.3k
            Tracev((stderr, "inflate:       codes ok\n"));
1020
12.3k
            state->mode = LEN_;
1021
12.3k
            if (flush == Z_TREES) goto inf_leave;
1022
                /* fallthrough */
1023
26.6k
        case LEN_:
1024
26.6k
            state->mode = LEN;
1025
                /* fallthrough */
1026
507k
        case LEN:
1027
507k
            if (have >= 6 && left >= 258) {
1028
60.8k
                RESTORE();
1029
60.8k
                inflate_fast(strm, out);
1030
60.8k
                LOAD();
1031
60.8k
                if (state->mode == TYPE)
1032
13.6k
                    state->back = -1;
1033
60.8k
                break;
1034
60.8k
            }
1035
446k
            state->back = 0;
1036
697k
            for (;;) {
1037
697k
                here = state->lencode[BITS(state->lenbits)];
1038
697k
                if ((unsigned)(here.bits) <= bits) break;
1039
355k
                PULLBYTE();
1040
355k
            }
1041
341k
            if (here.op && (here.op & 0xf0) == 0) {
1042
30.1k
                last = here;
1043
32.3k
                for (;;) {
1044
32.3k
                    here = state->lencode[last.val +
1045
32.3k
                            (BITS(last.bits + last.op) >> last.bits)];
1046
32.3k
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1047
4.12k
                    PULLBYTE();
1048
4.12k
                }
1049
28.2k
                DROPBITS(last.bits);
1050
28.2k
                state->back += last.bits;
1051
28.2k
            }
1052
339k
            DROPBITS(here.bits);
1053
339k
            state->back += here.bits;
1054
339k
            state->length = (unsigned)here.val;
1055
339k
            if ((int)(here.op) == 0) {
1056
188k
                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1057
188k
                        "inflate:         literal '%c'\n" :
1058
188k
                        "inflate:         literal 0x%02x\n", here.val));
1059
188k
                state->mode = LIT;
1060
188k
                break;
1061
188k
            }
1062
151k
            if (here.op & 32) {
1063
8.98k
                Tracevv((stderr, "inflate:         end of block\n"));
1064
8.98k
                state->back = -1;
1065
8.98k
                state->mode = TYPE;
1066
8.98k
                break;
1067
8.98k
            }
1068
142k
            if (here.op & 64) {
1069
25
                strm->msg = (z_const char *)"invalid literal/length code";
1070
25
                state->mode = BAD;
1071
25
                break;
1072
25
            }
1073
142k
            state->extra = (unsigned)(here.op) & 15;
1074
142k
            state->mode = LENEXT;
1075
                /* fallthrough */
1076
143k
        case LENEXT:
1077
143k
            if (state->extra) {
1078
31.9k
                NEEDBITS(state->extra);
1079
30.5k
                state->length += BITS(state->extra);
1080
30.5k
                DROPBITS(state->extra);
1081
30.5k
                state->back += state->extra;
1082
30.5k
            }
1083
141k
            Tracevv((stderr, "inflate:         length %u\n", state->length));
1084
141k
            state->was = state->length;
1085
141k
            state->mode = DIST;
1086
                /* fallthrough */
1087
154k
        case DIST:
1088
200k
            for (;;) {
1089
200k
                here = state->distcode[BITS(state->distbits)];
1090
200k
                if ((unsigned)(here.bits) <= bits) break;
1091
58.5k
                PULLBYTE();
1092
58.5k
            }
1093
141k
            if ((here.op & 0xf0) == 0) {
1094
3.01k
                last = here;
1095
4.49k
                for (;;) {
1096
4.49k
                    here = state->distcode[last.val +
1097
4.49k
                            (BITS(last.bits + last.op) >> last.bits)];
1098
4.49k
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1099
1.84k
                    PULLBYTE();
1100
1.84k
                }
1101
2.65k
                DROPBITS(last.bits);
1102
2.65k
                state->back += last.bits;
1103
2.65k
            }
1104
141k
            DROPBITS(here.bits);
1105
141k
            state->back += here.bits;
1106
141k
            if (here.op & 64) {
1107
10
                strm->msg = (z_const char *)"invalid distance code";
1108
10
                state->mode = BAD;
1109
10
                break;
1110
10
            }
1111
141k
            state->offset = (unsigned)here.val;
1112
141k
            state->extra = (unsigned)(here.op) & 15;
1113
141k
            state->mode = DISTEXT;
1114
                /* fallthrough */
1115
156k
        case DISTEXT:
1116
156k
            if (state->extra) {
1117
110k
                NEEDBITS(state->extra);
1118
94.6k
                state->offset += BITS(state->extra);
1119
94.6k
                DROPBITS(state->extra);
1120
94.6k
                state->back += state->extra;
1121
94.6k
            }
1122
#ifdef INFLATE_STRICT
1123
            if (state->offset > state->dmax) {
1124
                strm->msg = (z_const char *)"invalid distance too far back";
1125
                state->mode = BAD;
1126
                break;
1127
            }
1128
#endif
1129
141k
            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
1130
141k
            state->mode = MATCH;
1131
                /* fallthrough */
1132
149k
        case MATCH:
1133
149k
            if (left == 0) goto inf_leave;
1134
149k
            copy = out - left;
1135
149k
            if (state->offset > copy) {         /* copy from window */
1136
70.0k
                copy = state->offset - copy;
1137
70.0k
                if (copy > state->whave) {
1138
90
                    if (state->sane) {
1139
90
                        strm->msg = (z_const char *)"invalid distance too far back";
1140
90
                        state->mode = BAD;
1141
90
                        break;
1142
90
                    }
1143
#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1144
                    Trace((stderr, "inflate.c too far\n"));
1145
                    copy -= state->whave;
1146
                    if (copy > state->length) copy = state->length;
1147
                    if (copy > left) copy = left;
1148
                    left -= copy;
1149
                    state->length -= copy;
1150
                    do {
1151
                        *put++ = 0;
1152
                    } while (--copy);
1153
                    if (state->length == 0) state->mode = LEN;
1154
                    break;
1155
#endif
1156
90
                }
1157
69.9k
                if (copy > state->wnext) {
1158
6.07k
                    copy -= state->wnext;
1159
6.07k
                    from = state->window + (state->wsize - copy);
1160
6.07k
                }
1161
63.9k
                else
1162
63.9k
                    from = state->window + (state->wnext - copy);
1163
69.9k
                if (copy > state->length) copy = state->length;
1164
69.9k
            }
1165
79.3k
            else {                              /* copy from output */
1166
79.3k
                from = put - state->offset;
1167
79.3k
                copy = state->length;
1168
79.3k
            }
1169
149k
            if (copy > left) copy = left;
1170
149k
            left -= copy;
1171
149k
            state->length -= copy;
1172
13.7M
            do {
1173
13.7M
                *put++ = *from++;
1174
13.7M
            } while (--copy);
1175
149k
            if (state->length == 0) state->mode = LEN;
1176
149k
            break;
1177
188k
        case LIT:
1178
188k
            if (left == 0) goto inf_leave;
1179
188k
            *put++ = (unsigned char)(state->length);
1180
188k
            left--;
1181
188k
            state->mode = LEN;
1182
188k
            break;
1183
12.4k
        case CHECK:
1184
12.4k
            if (state->wrap) {
1185
12.4k
                NEEDBITS(32);
1186
11.9k
                out -= left;
1187
11.9k
                strm->total_out += out;
1188
11.9k
                state->total += out;
1189
11.9k
                if ((state->wrap & 4) && out)
1190
9.87k
                    strm->adler = state->check =
1191
9.87k
                        UPDATE_CHECK(state->check, put - out, out);
1192
11.9k
                out = left;
1193
11.9k
                if ((state->wrap & 4) && (
1194
11.9k
#ifdef GUNZIP
1195
11.9k
                     state->flags ? hold :
1196
11.9k
#endif
1197
11.9k
                     ZSWAP32(hold)) != state->check) {
1198
1.51k
                    strm->msg = (z_const char *)"incorrect data check";
1199
1.51k
                    state->mode = BAD;
1200
1.51k
                    break;
1201
1.51k
                }
1202
10.4k
                INITBITS();
1203
10.4k
                Tracev((stderr, "inflate:   check matches trailer\n"));
1204
10.4k
            }
1205
10.4k
#ifdef GUNZIP
1206
10.4k
            state->mode = LENGTH;
1207
                /* fallthrough */
1208
10.4k
        case LENGTH:
1209
10.4k
            if (state->wrap && state->flags) {
1210
0
                NEEDBITS(32);
1211
0
                if ((state->wrap & 4) && hold != (state->total & 0xffffffff)) {
1212
0
                    strm->msg = (z_const char *)"incorrect length check";
1213
0
                    state->mode = BAD;
1214
0
                    break;
1215
0
                }
1216
0
                INITBITS();
1217
0
                Tracev((stderr, "inflate:   length matches trailer\n"));
1218
0
            }
1219
10.4k
#endif
1220
10.4k
            state->mode = DONE;
1221
                /* fallthrough */
1222
20.9k
        case DONE:
1223
20.9k
            ret = Z_STREAM_END;
1224
20.9k
            goto inf_leave;
1225
9.60k
        case BAD:
1226
9.60k
            ret = Z_DATA_ERROR;
1227
9.60k
            goto inf_leave;
1228
0
        case MEM:
1229
0
            return Z_MEM_ERROR;
1230
0
        case SYNC:
1231
                /* fallthrough */
1232
0
        default:
1233
0
            return Z_STREAM_ERROR;
1234
835k
        }
1235
1236
    /*
1237
       Return from inflate(), updating the total counts and the check value.
1238
       If there was no progress during the inflate() call, return a buffer
1239
       error.  Call updatewindow() to create and/or update the window state.
1240
       Note: a memory error from inflate() is non-recoverable.
1241
     */
1242
175k
  inf_leave:
1243
175k
    RESTORE();
1244
175k
    if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
1245
39.6k
            (state->mode < CHECK || flush != Z_FINISH)))
1246
139k
        if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
1247
0
            state->mode = MEM;
1248
0
            return Z_MEM_ERROR;
1249
0
        }
1250
175k
    in -= strm->avail_in;
1251
175k
    out -= strm->avail_out;
1252
175k
    strm->total_in += in;
1253
175k
    strm->total_out += out;
1254
175k
    state->total += out;
1255
175k
    if ((state->wrap & 4) && out)
1256
123k
        strm->adler = state->check =
1257
123k
            UPDATE_CHECK(state->check, strm->next_out - out, out);
1258
175k
    strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
1259
175k
                      (state->mode == TYPE ? 128 : 0) +
1260
175k
                      (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1261
175k
    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1262
2.97k
        ret = Z_BUF_ERROR;
1263
175k
    return ret;
1264
175k
}
1265
1266
18.2k
int ZEXPORT inflateEnd(z_streamp strm) {
1267
18.2k
    struct inflate_state FAR *state;
1268
18.2k
    if (inflateStateCheck(strm))
1269
0
        return Z_STREAM_ERROR;
1270
18.2k
    state = (struct inflate_state FAR *)strm->state;
1271
18.2k
    if (state->window != Z_NULL) ZFREE(strm, state->window);
1272
18.2k
    ZFREE(strm, strm->state);
1273
18.2k
    strm->state = Z_NULL;
1274
18.2k
    Tracev((stderr, "inflate: end\n"));
1275
18.2k
    return Z_OK;
1276
18.2k
}
1277
1278
int ZEXPORT inflateGetDictionary(z_streamp strm, Bytef *dictionary,
1279
0
                                 uInt *dictLength) {
1280
0
    struct inflate_state FAR *state;
1281
1282
    /* check state */
1283
0
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1284
0
    state = (struct inflate_state FAR *)strm->state;
1285
1286
    /* copy dictionary */
1287
0
    if (state->whave && dictionary != Z_NULL) {
1288
0
        zmemcpy(dictionary, state->window + state->wnext,
1289
0
                state->whave - state->wnext);
1290
0
        zmemcpy(dictionary + state->whave - state->wnext,
1291
0
                state->window, state->wnext);
1292
0
    }
1293
0
    if (dictLength != Z_NULL)
1294
0
        *dictLength = state->whave;
1295
0
    return Z_OK;
1296
0
}
1297
1298
int ZEXPORT inflateSetDictionary(z_streamp strm, const Bytef *dictionary,
1299
0
                                 uInt dictLength) {
1300
0
    struct inflate_state FAR *state;
1301
0
    unsigned long dictid;
1302
0
    int ret;
1303
1304
    /* check state */
1305
0
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1306
0
    state = (struct inflate_state FAR *)strm->state;
1307
0
    if (state->wrap != 0 && state->mode != DICT)
1308
0
        return Z_STREAM_ERROR;
1309
1310
    /* check for correct dictionary identifier */
1311
0
    if (state->mode == DICT) {
1312
0
        dictid = adler32(0L, Z_NULL, 0);
1313
0
        dictid = adler32(dictid, dictionary, dictLength);
1314
0
        if (dictid != state->check)
1315
0
            return Z_DATA_ERROR;
1316
0
    }
1317
1318
    /* copy dictionary to window using updatewindow(), which will amend the
1319
       existing dictionary if appropriate */
1320
0
    ret = updatewindow(strm, dictionary + dictLength, dictLength);
1321
0
    if (ret) {
1322
0
        state->mode = MEM;
1323
0
        return Z_MEM_ERROR;
1324
0
    }
1325
0
    state->havedict = 1;
1326
0
    Tracev((stderr, "inflate:   dictionary set\n"));
1327
0
    return Z_OK;
1328
0
}
1329
1330
0
int ZEXPORT inflateGetHeader(z_streamp strm, gz_headerp head) {
1331
0
    struct inflate_state FAR *state;
1332
1333
    /* check state */
1334
0
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1335
0
    state = (struct inflate_state FAR *)strm->state;
1336
0
    if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
1337
1338
    /* save header structure */
1339
0
    state->head = head;
1340
0
    head->done = 0;
1341
0
    return Z_OK;
1342
0
}
1343
1344
/*
1345
   Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff.  Return when found
1346
   or when out of input.  When called, *have is the number of pattern bytes
1347
   found in order so far, in 0..3.  On return *have is updated to the new
1348
   state.  If on return *have equals four, then the pattern was found and the
1349
   return value is how many bytes were read including the last byte of the
1350
   pattern.  If *have is less than four, then the pattern has not been found
1351
   yet and the return value is len.  In the latter case, syncsearch() can be
1352
   called again with more data and the *have state.  *have is initialized to
1353
   zero for the first call.
1354
 */
1355
local unsigned syncsearch(unsigned FAR *have, const unsigned char FAR *buf,
1356
0
                          unsigned len) {
1357
0
    unsigned got;
1358
0
    unsigned next;
1359
1360
0
    got = *have;
1361
0
    next = 0;
1362
0
    while (next < len && got < 4) {
1363
0
        if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
1364
0
            got++;
1365
0
        else if (buf[next])
1366
0
            got = 0;
1367
0
        else
1368
0
            got = 4 - got;
1369
0
        next++;
1370
0
    }
1371
0
    *have = got;
1372
0
    return next;
1373
0
}
1374
1375
0
int ZEXPORT inflateSync(z_streamp strm) {
1376
0
    unsigned len;               /* number of bytes to look at or looked at */
1377
0
    int flags;                  /* temporary to save header status */
1378
0
    unsigned long in, out;      /* temporary to save total_in and total_out */
1379
0
    unsigned char buf[4];       /* to restore bit buffer to byte string */
1380
0
    struct inflate_state FAR *state;
1381
1382
    /* check parameters */
1383
0
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1384
0
    state = (struct inflate_state FAR *)strm->state;
1385
0
    if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
1386
1387
    /* if first time, start search in bit buffer */
1388
0
    if (state->mode != SYNC) {
1389
0
        state->mode = SYNC;
1390
0
        state->hold >>= state->bits & 7;
1391
0
        state->bits -= state->bits & 7;
1392
0
        len = 0;
1393
0
        while (state->bits >= 8) {
1394
0
            buf[len++] = (unsigned char)(state->hold);
1395
0
            state->hold >>= 8;
1396
0
            state->bits -= 8;
1397
0
        }
1398
0
        state->have = 0;
1399
0
        syncsearch(&(state->have), buf, len);
1400
0
    }
1401
1402
    /* search available input */
1403
0
    len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
1404
0
    strm->avail_in -= len;
1405
0
    strm->next_in += len;
1406
0
    strm->total_in += len;
1407
1408
    /* return no joy or set up to restart inflate() on a new block */
1409
0
    if (state->have != 4) return Z_DATA_ERROR;
1410
0
    if (state->flags == -1)
1411
0
        state->wrap = 0;    /* if no header yet, treat as raw */
1412
0
    else
1413
0
        state->wrap &= ~4;  /* no point in computing a check value now */
1414
0
    flags = state->flags;
1415
0
    in = strm->total_in;  out = strm->total_out;
1416
0
    inflateReset(strm);
1417
0
    strm->total_in = in;  strm->total_out = out;
1418
0
    state->flags = flags;
1419
0
    state->mode = TYPE;
1420
0
    return Z_OK;
1421
0
}
1422
1423
/*
1424
   Returns true if inflate is currently at the end of a block generated by
1425
   Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
1426
   implementation to provide an additional safety check. PPP uses
1427
   Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
1428
   block. When decompressing, PPP checks that at the end of input packet,
1429
   inflate is waiting for these length bytes.
1430
 */
1431
0
int ZEXPORT inflateSyncPoint(z_streamp strm) {
1432
0
    struct inflate_state FAR *state;
1433
1434
0
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1435
0
    state = (struct inflate_state FAR *)strm->state;
1436
0
    return state->mode == STORED && state->bits == 0;
1437
0
}
1438
1439
0
int ZEXPORT inflateCopy(z_streamp dest, z_streamp source) {
1440
0
    struct inflate_state FAR *state;
1441
0
    struct inflate_state FAR *copy;
1442
0
    unsigned char FAR *window;
1443
0
    unsigned wsize;
1444
1445
    /* check input */
1446
0
    if (inflateStateCheck(source) || dest == Z_NULL)
1447
0
        return Z_STREAM_ERROR;
1448
0
    state = (struct inflate_state FAR *)source->state;
1449
1450
    /* allocate space */
1451
0
    copy = (struct inflate_state FAR *)
1452
0
           ZALLOC(source, 1, sizeof(struct inflate_state));
1453
0
    if (copy == Z_NULL) return Z_MEM_ERROR;
1454
0
    window = Z_NULL;
1455
0
    if (state->window != Z_NULL) {
1456
0
        window = (unsigned char FAR *)
1457
0
                 ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
1458
0
        if (window == Z_NULL) {
1459
0
            ZFREE(source, copy);
1460
0
            return Z_MEM_ERROR;
1461
0
        }
1462
0
    }
1463
1464
    /* copy state */
1465
0
    zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
1466
0
    zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state));
1467
0
    copy->strm = dest;
1468
0
    if (state->lencode >= state->codes &&
1469
0
        state->lencode <= state->codes + ENOUGH - 1) {
1470
0
        copy->lencode = copy->codes + (state->lencode - state->codes);
1471
0
        copy->distcode = copy->codes + (state->distcode - state->codes);
1472
0
    }
1473
0
    copy->next = copy->codes + (state->next - state->codes);
1474
0
    if (window != Z_NULL) {
1475
0
        wsize = 1U << state->wbits;
1476
0
        zmemcpy(window, state->window, wsize);
1477
0
    }
1478
0
    copy->window = window;
1479
0
    dest->state = (struct internal_state FAR *)copy;
1480
0
    return Z_OK;
1481
0
}
1482
1483
0
int ZEXPORT inflateUndermine(z_streamp strm, int subvert) {
1484
0
    struct inflate_state FAR *state;
1485
1486
0
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1487
0
    state = (struct inflate_state FAR *)strm->state;
1488
#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1489
    state->sane = !subvert;
1490
    return Z_OK;
1491
#else
1492
0
    (void)subvert;
1493
0
    state->sane = 1;
1494
0
    return Z_DATA_ERROR;
1495
0
#endif
1496
0
}
1497
1498
0
int ZEXPORT inflateValidate(z_streamp strm, int check) {
1499
0
    struct inflate_state FAR *state;
1500
1501
0
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
1502
0
    state = (struct inflate_state FAR *)strm->state;
1503
0
    if (check && state->wrap)
1504
0
        state->wrap |= 4;
1505
0
    else
1506
0
        state->wrap &= ~4;
1507
0
    return Z_OK;
1508
0
}
1509
1510
0
long ZEXPORT inflateMark(z_streamp strm) {
1511
0
    struct inflate_state FAR *state;
1512
1513
0
    if (inflateStateCheck(strm))
1514
0
        return -(1L << 16);
1515
0
    state = (struct inflate_state FAR *)strm->state;
1516
0
    return (long)(((unsigned long)((long)state->back)) << 16) +
1517
0
        (state->mode == COPY ? state->length :
1518
0
            (state->mode == MATCH ? state->was - state->length : 0));
1519
0
}
1520
1521
0
unsigned long ZEXPORT inflateCodesUsed(z_streamp strm) {
1522
0
    struct inflate_state FAR *state;
1523
0
    if (inflateStateCheck(strm)) return (unsigned long)-1;
1524
0
    state = (struct inflate_state FAR *)strm->state;
1525
0
    return (unsigned long)(state->next - state->codes);
1526
0
}