Coverage Report

Created: 2024-09-16 06:12

/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
373k
local int inflateStateCheck(z_streamp strm) {
95
373k
    struct inflate_state FAR *state;
96
373k
    if (strm == Z_NULL ||
97
373k
        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
98
0
        return 1;
99
373k
    state = (struct inflate_state FAR *)strm->state;
100
373k
    if (state == Z_NULL || state->strm != strm ||
101
373k
        state->mode < HEAD || state->mode > SYNC)
102
0
        return 1;
103
373k
    return 0;
104
373k
}
105
106
65.3k
int ZEXPORT inflateResetKeep(z_streamp strm) {
107
65.3k
    struct inflate_state FAR *state;
108
109
65.3k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
110
65.3k
    state = (struct inflate_state FAR *)strm->state;
111
65.3k
    strm->total_in = strm->total_out = state->total = 0;
112
65.3k
    strm->msg = Z_NULL;
113
65.3k
    if (state->wrap)        /* to support ill-conceived Java test suite */
114
65.3k
        strm->adler = state->wrap & 1;
115
65.3k
    state->mode = HEAD;
116
65.3k
    state->last = 0;
117
65.3k
    state->havedict = 0;
118
65.3k
    state->flags = -1;
119
65.3k
    state->dmax = 32768U;
120
65.3k
    state->head = Z_NULL;
121
65.3k
    state->hold = 0;
122
65.3k
    state->bits = 0;
123
65.3k
    state->lencode = state->distcode = state->next = state->codes;
124
65.3k
    state->sane = 1;
125
65.3k
    state->back = -1;
126
65.3k
    Tracev((stderr, "inflate: reset\n"));
127
65.3k
    return Z_OK;
128
65.3k
}
129
130
65.3k
int ZEXPORT inflateReset(z_streamp strm) {
131
65.3k
    struct inflate_state FAR *state;
132
133
65.3k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
134
65.3k
    state = (struct inflate_state FAR *)strm->state;
135
65.3k
    state->wsize = 0;
136
65.3k
    state->whave = 0;
137
65.3k
    state->wnext = 0;
138
65.3k
    return inflateResetKeep(strm);
139
65.3k
}
140
141
65.3k
int ZEXPORT inflateReset2(z_streamp strm, int windowBits) {
142
65.3k
    int wrap;
143
65.3k
    struct inflate_state FAR *state;
144
145
    /* get the state */
146
65.3k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
147
65.3k
    state = (struct inflate_state FAR *)strm->state;
148
149
    /* extract wrap request from windowBits parameter */
150
65.3k
    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
65.3k
    else {
157
65.3k
        wrap = (windowBits >> 4) + 5;
158
65.3k
#ifdef GUNZIP
159
65.3k
        if (windowBits < 48)
160
65.3k
            windowBits &= 15;
161
65.3k
#endif
162
65.3k
    }
163
164
    /* set number of window bits, free window if different */
165
65.3k
    if (windowBits && (windowBits < 8 || windowBits > 15))
166
0
        return Z_STREAM_ERROR;
167
65.3k
    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
65.3k
    state->wrap = wrap;
174
65.3k
    state->wbits = (unsigned)windowBits;
175
65.3k
    return inflateReset(strm);
176
65.3k
}
177
178
int ZEXPORT inflateInit2_(z_streamp strm, int windowBits,
179
65.3k
                          const char *version, int stream_size) {
180
65.3k
    int ret;
181
65.3k
    struct inflate_state FAR *state;
182
183
65.3k
    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
184
65.3k
        stream_size != (int)(sizeof(z_stream)))
185
0
        return Z_VERSION_ERROR;
186
65.3k
    if (strm == Z_NULL) return Z_STREAM_ERROR;
187
65.3k
    strm->msg = Z_NULL;                 /* in case we return an error */
188
65.3k
    if (strm->zalloc == (alloc_func)0) {
189
#ifdef Z_SOLO
190
        return Z_STREAM_ERROR;
191
#else
192
65.3k
        strm->zalloc = zcalloc;
193
65.3k
        strm->opaque = (voidpf)0;
194
65.3k
#endif
195
65.3k
    }
196
65.3k
    if (strm->zfree == (free_func)0)
197
#ifdef Z_SOLO
198
        return Z_STREAM_ERROR;
199
#else
200
65.3k
        strm->zfree = zcfree;
201
65.3k
#endif
202
65.3k
    state = (struct inflate_state FAR *)
203
65.3k
            ZALLOC(strm, 1, sizeof(struct inflate_state));
204
65.3k
    if (state == Z_NULL) return Z_MEM_ERROR;
205
65.3k
    Tracev((stderr, "inflate: allocated\n"));
206
65.3k
    strm->state = (struct internal_state FAR *)state;
207
65.3k
    state->strm = strm;
208
65.3k
    state->window = Z_NULL;
209
65.3k
    state->mode = HEAD;     /* to pass state test in inflateReset2() */
210
65.3k
    ret = inflateReset2(strm, windowBits);
211
65.3k
    if (ret != Z_OK) {
212
0
        ZFREE(strm, state);
213
0
        strm->state = Z_NULL;
214
0
    }
215
65.3k
    return ret;
216
65.3k
}
217
218
int ZEXPORT inflateInit_(z_streamp strm, const char *version,
219
65.3k
                         int stream_size) {
220
65.3k
    return inflateInit2_(strm, DEF_WBITS, version, stream_size);
221
65.3k
}
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
33.3k
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
33.3k
#   include "inffixed.h"
286
33.3k
#endif /* BUILDFIXED */
287
33.3k
    state->lencode = lenfix;
288
33.3k
    state->lenbits = 9;
289
33.3k
    state->distcode = distfix;
290
33.3k
    state->distbits = 5;
291
33.3k
}
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
112k
local int updatewindow(z_streamp strm, const Bytef *end, unsigned copy) {
369
112k
    struct inflate_state FAR *state;
370
112k
    unsigned dist;
371
372
112k
    state = (struct inflate_state FAR *)strm->state;
373
374
    /* if it hasn't been done already, allocate space for the window */
375
112k
    if (state->window == Z_NULL) {
376
65.3k
        state->window = (unsigned char FAR *)
377
65.3k
                        ZALLOC(strm, 1U << state->wbits,
378
65.3k
                               sizeof(unsigned char));
379
65.3k
        if (state->window == Z_NULL) return 1;
380
65.3k
    }
381
382
    /* if window not in use yet, initialize */
383
112k
    if (state->wsize == 0) {
384
65.3k
        state->wsize = 1U << state->wbits;
385
65.3k
        state->wnext = 0;
386
65.3k
        state->whave = 0;
387
65.3k
    }
388
389
    /* copy state->wsize or less output bytes into the circular window */
390
112k
    if (copy >= state->wsize) {
391
0
        zmemcpy(state->window, end - state->wsize, state->wsize);
392
0
        state->wnext = 0;
393
0
        state->whave = state->wsize;
394
0
    }
395
112k
    else {
396
112k
        dist = state->wsize - state->wnext;
397
112k
        if (dist > copy) dist = copy;
398
112k
        zmemcpy(state->window + state->wnext, end - copy, dist);
399
112k
        copy -= dist;
400
112k
        if (copy) {
401
0
            zmemcpy(state->window, end - copy, copy);
402
0
            state->wnext = copy;
403
0
            state->whave = state->wsize;
404
0
        }
405
112k
        else {
406
112k
            state->wnext += dist;
407
112k
            if (state->wnext == state->wsize) state->wnext = 0;
408
112k
            if (state->whave < state->wsize) state->whave += dist;
409
112k
        }
410
112k
    }
411
112k
    return 0;
412
112k
}
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
112k
    (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
143k
    do { \
446
143k
        put = strm->next_out; \
447
143k
        left = strm->avail_out; \
448
143k
        next = strm->next_in; \
449
143k
        have = strm->avail_in; \
450
143k
        hold = state->hold; \
451
143k
        bits = state->bits; \
452
143k
    } while (0)
453
454
/* Restore state from registers in inflate() */
455
#define RESTORE() \
456
143k
    do { \
457
143k
        strm->next_out = put; \
458
143k
        strm->avail_out = left; \
459
143k
        strm->next_in = next; \
460
143k
        strm->avail_in = have; \
461
143k
        state->hold = hold; \
462
143k
        state->bits = bits; \
463
143k
    } while (0)
464
465
/* Clear the input bit accumulator */
466
#define INITBITS() \
467
112k
    do { \
468
112k
        hold = 0; \
469
112k
        bits = 0; \
470
112k
    } 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
8.37M
    do { \
476
8.37M
        if (have == 0) goto inf_leave; \
477
8.37M
        have--; \
478
8.37M
        hold += (unsigned long)(*next++) << bits; \
479
8.37M
        bits += 8; \
480
8.37M
    } 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
1.82M
    do { \
486
2.97M
        while (bits < (unsigned)(n)) \
487
1.82M
            PULLBYTE(); \
488
1.82M
    } while (0)
489
490
/* Return the low n bits of the bit accumulator (n < 16) */
491
#define BITS(n) \
492
20.3M
    ((unsigned)hold & ((1U << (n)) - 1))
493
494
/* Remove n bits from the bit accumulator */
495
#define DROPBITS(n) \
496
12.9M
    do { \
497
12.9M
        hold >>= (n); \
498
12.9M
        bits -= (unsigned)(n); \
499
12.9M
    } while (0)
500
501
/* Remove zero to seven bits as needed to go to a byte boundary */
502
#define BYTEBITS() \
503
46.7k
    do { \
504
46.7k
        hold >>= bits & 7; \
505
46.7k
        bits -= bits & 7; \
506
46.7k
    } 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
112k
int ZEXPORT inflate(z_streamp strm, int flush) {
591
112k
    struct inflate_state FAR *state;
592
112k
    z_const unsigned char FAR *next;    /* next input */
593
112k
    unsigned char FAR *put;     /* next output */
594
112k
    unsigned have, left;        /* available input and output */
595
112k
    unsigned long hold;         /* bit buffer */
596
112k
    unsigned bits;              /* bits in bit buffer */
597
112k
    unsigned in, out;           /* save starting available input and output */
598
112k
    unsigned copy;              /* number of stored or match bytes to copy */
599
112k
    unsigned char FAR *from;    /* where to copy match bytes from */
600
112k
    code here;                  /* current decoding table entry */
601
112k
    code last;                  /* parent table entry */
602
112k
    unsigned len;               /* length to copy for repeats, bits to drop */
603
112k
    int ret;                    /* return code */
604
112k
#ifdef GUNZIP
605
112k
    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
606
112k
#endif
607
112k
    static const unsigned short order[19] = /* permutation of code lengths */
608
112k
        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
609
610
112k
    if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
611
112k
        (strm->next_in == Z_NULL && strm->avail_in != 0))
612
0
        return Z_STREAM_ERROR;
613
614
112k
    state = (struct inflate_state FAR *)strm->state;
615
112k
    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
616
112k
    LOAD();
617
112k
    in = have;
618
112k
    out = left;
619
112k
    ret = Z_OK;
620
112k
    for (;;)
621
10.9M
        switch (state->mode) {
622
65.3k
        case HEAD:
623
65.3k
            if (state->wrap == 0) {
624
0
                state->mode = TYPEDO;
625
0
                break;
626
0
            }
627
65.3k
            NEEDBITS(16);
628
65.3k
#ifdef GUNZIP
629
65.3k
            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
65.3k
            if (state->head != Z_NULL)
639
0
                state->head->done = -1;
640
65.3k
            if (!(state->wrap & 1) ||   /* check if zlib header allowed */
641
#else
642
            if (
643
#endif
644
65.3k
                ((BITS(8) << 8) + (hold >> 8)) % 31) {
645
0
                strm->msg = (z_const char *)"incorrect header check";
646
0
                state->mode = BAD;
647
0
                break;
648
0
            }
649
65.3k
            if (BITS(4) != Z_DEFLATED) {
650
0
                strm->msg = (z_const char *)"unknown compression method";
651
0
                state->mode = BAD;
652
0
                break;
653
0
            }
654
65.3k
            DROPBITS(4);
655
65.3k
            len = BITS(4) + 8;
656
65.3k
            if (state->wbits == 0)
657
0
                state->wbits = len;
658
65.3k
            if (len > 15 || len > state->wbits) {
659
0
                strm->msg = (z_const char *)"invalid window size";
660
0
                state->mode = BAD;
661
0
                break;
662
0
            }
663
65.3k
            state->dmax = 1U << len;
664
65.3k
            state->flags = 0;               /* indicate zlib header */
665
65.3k
            Tracev((stderr, "inflate:   zlib header ok\n"));
666
65.3k
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
667
65.3k
            state->mode = hold & 0x200 ? DICTID : TYPE;
668
65.3k
            INITBITS();
669
65.3k
            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
0
        case DICTID:
811
0
            NEEDBITS(32);
812
0
            strm->adler = state->check = ZSWAP32(hold);
813
0
            INITBITS();
814
0
            state->mode = DICT;
815
                /* fallthrough */
816
0
        case DICT:
817
0
            if (state->havedict == 0) {
818
0
                RESTORE();
819
0
                return Z_NEED_DICT;
820
0
            }
821
0
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
822
0
            state->mode = TYPE;
823
                /* fallthrough */
824
112k
        case TYPE:
825
112k
            if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
826
                /* fallthrough */
827
112k
        case TYPEDO:
828
112k
            if (state->last) {
829
46.7k
                BYTEBITS();
830
46.7k
                state->mode = CHECK;
831
46.7k
                break;
832
46.7k
            }
833
65.3k
            NEEDBITS(3);
834
65.3k
            state->last = BITS(1);
835
65.3k
            DROPBITS(1);
836
65.3k
            switch (BITS(2)) {
837
0
            case 0:                             /* stored block */
838
0
                Tracev((stderr, "inflate:     stored block%s\n",
839
0
                        state->last ? " (last)" : ""));
840
0
                state->mode = STORED;
841
0
                break;
842
33.3k
            case 1:                             /* fixed block */
843
33.3k
                fixedtables(state);
844
33.3k
                Tracev((stderr, "inflate:     fixed codes block%s\n",
845
33.3k
                        state->last ? " (last)" : ""));
846
33.3k
                state->mode = LEN_;             /* decode codes */
847
33.3k
                if (flush == Z_TREES) {
848
0
                    DROPBITS(2);
849
0
                    goto inf_leave;
850
0
                }
851
33.3k
                break;
852
33.3k
            case 2:                             /* dynamic block */
853
32.0k
                Tracev((stderr, "inflate:     dynamic codes block%s\n",
854
32.0k
                        state->last ? " (last)" : ""));
855
32.0k
                state->mode = TABLE;
856
32.0k
                break;
857
0
            case 3:
858
0
                strm->msg = (z_const char *)"invalid block type";
859
0
                state->mode = BAD;
860
65.3k
            }
861
65.3k
            DROPBITS(2);
862
65.3k
            break;
863
0
        case STORED:
864
0
            BYTEBITS();                         /* go to byte boundary */
865
0
            NEEDBITS(32);
866
0
            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
867
0
                strm->msg = (z_const char *)"invalid stored block lengths";
868
0
                state->mode = BAD;
869
0
                break;
870
0
            }
871
0
            state->length = (unsigned)hold & 0xffff;
872
0
            Tracev((stderr, "inflate:       stored length %u\n",
873
0
                    state->length));
874
0
            INITBITS();
875
0
            state->mode = COPY_;
876
0
            if (flush == Z_TREES) goto inf_leave;
877
                /* fallthrough */
878
0
        case COPY_:
879
0
            state->mode = COPY;
880
                /* fallthrough */
881
0
        case COPY:
882
0
            copy = state->length;
883
0
            if (copy) {
884
0
                if (copy > have) copy = have;
885
0
                if (copy > left) copy = left;
886
0
                if (copy == 0) goto inf_leave;
887
0
                zmemcpy(put, next, copy);
888
0
                have -= copy;
889
0
                next += copy;
890
0
                left -= copy;
891
0
                put += copy;
892
0
                state->length -= copy;
893
0
                break;
894
0
            }
895
0
            Tracev((stderr, "inflate:       stored end\n"));
896
0
            state->mode = TYPE;
897
0
            break;
898
32.0k
        case TABLE:
899
32.0k
            NEEDBITS(14);
900
32.0k
            state->nlen = BITS(5) + 257;
901
32.0k
            DROPBITS(5);
902
32.0k
            state->ndist = BITS(5) + 1;
903
32.0k
            DROPBITS(5);
904
32.0k
            state->ncode = BITS(4) + 4;
905
32.0k
            DROPBITS(4);
906
32.0k
#ifndef PKZIP_BUG_WORKAROUND
907
32.0k
            if (state->nlen > 286 || state->ndist > 30) {
908
0
                strm->msg = (z_const char *)"too many length or distance symbols";
909
0
                state->mode = BAD;
910
0
                break;
911
0
            }
912
32.0k
#endif
913
32.0k
            Tracev((stderr, "inflate:       table sizes ok\n"));
914
32.0k
            state->have = 0;
915
32.0k
            state->mode = LENLENS;
916
                /* fallthrough */
917
32.0k
        case LENLENS:
918
557k
            while (state->have < state->ncode) {
919
525k
                NEEDBITS(3);
920
525k
                state->lens[order[state->have++]] = (unsigned short)BITS(3);
921
525k
                DROPBITS(3);
922
525k
            }
923
115k
            while (state->have < 19)
924
83.5k
                state->lens[order[state->have++]] = 0;
925
32.0k
            state->next = state->codes;
926
32.0k
            state->lencode = state->distcode = (const code FAR *)(state->next);
927
32.0k
            state->lenbits = 7;
928
32.0k
            ret = inflate_table(CODES, state->lens, 19, &(state->next),
929
32.0k
                                &(state->lenbits), state->work);
930
32.0k
            if (ret) {
931
0
                strm->msg = (z_const char *)"invalid code lengths set";
932
0
                state->mode = BAD;
933
0
                break;
934
0
            }
935
32.0k
            Tracev((stderr, "inflate:       code lengths ok\n"));
936
32.0k
            state->have = 0;
937
32.0k
            state->mode = CODELENS;
938
                /* fallthrough */
939
32.0k
        case CODELENS:
940
5.03M
            while (state->have < state->nlen + state->ndist) {
941
6.75M
                for (;;) {
942
6.75M
                    here = state->lencode[BITS(state->lenbits)];
943
6.75M
                    if ((unsigned)(here.bits) <= bits) break;
944
1.75M
                    PULLBYTE();
945
1.75M
                }
946
5.00M
                if (here.val < 16) {
947
4.51M
                    DROPBITS(here.bits);
948
4.51M
                    state->lens[state->have++] = here.val;
949
4.51M
                }
950
483k
                else {
951
483k
                    if (here.val == 16) {
952
81.3k
                        NEEDBITS(here.bits + 2);
953
81.3k
                        DROPBITS(here.bits);
954
81.3k
                        if (state->have == 0) {
955
0
                            strm->msg = (z_const char *)"invalid bit length repeat";
956
0
                            state->mode = BAD;
957
0
                            break;
958
0
                        }
959
81.3k
                        len = state->lens[state->have - 1];
960
81.3k
                        copy = 3 + BITS(2);
961
81.3k
                        DROPBITS(2);
962
81.3k
                    }
963
401k
                    else if (here.val == 17) {
964
353k
                        NEEDBITS(here.bits + 3);
965
353k
                        DROPBITS(here.bits);
966
353k
                        len = 0;
967
353k
                        copy = 3 + BITS(3);
968
353k
                        DROPBITS(3);
969
353k
                    }
970
47.9k
                    else {
971
47.9k
                        NEEDBITS(here.bits + 7);
972
47.9k
                        DROPBITS(here.bits);
973
47.9k
                        len = 0;
974
47.9k
                        copy = 11 + BITS(7);
975
47.9k
                        DROPBITS(7);
976
47.9k
                    }
977
483k
                    if (state->have + copy > state->nlen + state->ndist) {
978
0
                        strm->msg = (z_const char *)"invalid bit length repeat";
979
0
                        state->mode = BAD;
980
0
                        break;
981
0
                    }
982
5.78M
                    while (copy--)
983
5.29M
                        state->lens[state->have++] = (unsigned short)len;
984
483k
                }
985
5.00M
            }
986
987
            /* handle error breaks in while */
988
32.0k
            if (state->mode == BAD) break;
989
990
            /* check for end-of-block code (better have one) */
991
32.0k
            if (state->lens[256] == 0) {
992
0
                strm->msg = (z_const char *)"invalid code -- missing end-of-block";
993
0
                state->mode = BAD;
994
0
                break;
995
0
            }
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
32.0k
            state->next = state->codes;
1001
32.0k
            state->lencode = (const code FAR *)(state->next);
1002
32.0k
            state->lenbits = 9;
1003
32.0k
            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1004
32.0k
                                &(state->lenbits), state->work);
1005
32.0k
            if (ret) {
1006
0
                strm->msg = (z_const char *)"invalid literal/lengths set";
1007
0
                state->mode = BAD;
1008
0
                break;
1009
0
            }
1010
32.0k
            state->distcode = (const code FAR *)(state->next);
1011
32.0k
            state->distbits = 6;
1012
32.0k
            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1013
32.0k
                            &(state->next), &(state->distbits), state->work);
1014
32.0k
            if (ret) {
1015
0
                strm->msg = (z_const char *)"invalid distances set";
1016
0
                state->mode = BAD;
1017
0
                break;
1018
0
            }
1019
32.0k
            Tracev((stderr, "inflate:       codes ok\n"));
1020
32.0k
            state->mode = LEN_;
1021
32.0k
            if (flush == Z_TREES) goto inf_leave;
1022
                /* fallthrough */
1023
65.3k
        case LEN_:
1024
65.3k
            state->mode = LEN;
1025
                /* fallthrough */
1026
5.61M
        case LEN:
1027
5.61M
            if (have >= 6 && left >= 258) {
1028
31.3k
                RESTORE();
1029
31.3k
                inflate_fast(strm, out);
1030
31.3k
                LOAD();
1031
31.3k
                if (state->mode == TYPE)
1032
0
                    state->back = -1;
1033
31.3k
                break;
1034
31.3k
            }
1035
5.58M
            state->back = 0;
1036
10.7M
            for (;;) {
1037
10.7M
                here = state->lencode[BITS(state->lenbits)];
1038
10.7M
                if ((unsigned)(here.bits) <= bits) break;
1039
5.21M
                PULLBYTE();
1040
5.21M
            }
1041
5.58M
            if (here.op && (here.op & 0xf0) == 0) {
1042
20.9k
                last = here;
1043
23.4k
                for (;;) {
1044
23.4k
                    here = state->lencode[last.val +
1045
23.4k
                            (BITS(last.bits + last.op) >> last.bits)];
1046
23.4k
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1047
2.58k
                    PULLBYTE();
1048
2.58k
                }
1049
20.9k
                DROPBITS(last.bits);
1050
20.9k
                state->back += last.bits;
1051
20.9k
            }
1052
5.58M
            DROPBITS(here.bits);
1053
5.58M
            state->back += here.bits;
1054
5.58M
            state->length = (unsigned)here.val;
1055
5.58M
            if ((int)(here.op) == 0) {
1056
5.05M
                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1057
5.05M
                        "inflate:         literal '%c'\n" :
1058
5.05M
                        "inflate:         literal 0x%02x\n", here.val));
1059
5.05M
                state->mode = LIT;
1060
5.05M
                break;
1061
5.05M
            }
1062
522k
            if (here.op & 32) {
1063
46.7k
                Tracevv((stderr, "inflate:         end of block\n"));
1064
46.7k
                state->back = -1;
1065
46.7k
                state->mode = TYPE;
1066
46.7k
                break;
1067
46.7k
            }
1068
475k
            if (here.op & 64) {
1069
0
                strm->msg = (z_const char *)"invalid literal/length code";
1070
0
                state->mode = BAD;
1071
0
                break;
1072
0
            }
1073
475k
            state->extra = (unsigned)(here.op) & 15;
1074
475k
            state->mode = LENEXT;
1075
                /* fallthrough */
1076
475k
        case LENEXT:
1077
475k
            if (state->extra) {
1078
185k
                NEEDBITS(state->extra);
1079
185k
                state->length += BITS(state->extra);
1080
185k
                DROPBITS(state->extra);
1081
185k
                state->back += state->extra;
1082
185k
            }
1083
475k
            Tracevv((stderr, "inflate:         length %u\n", state->length));
1084
475k
            state->was = state->length;
1085
475k
            state->mode = DIST;
1086
                /* fallthrough */
1087
475k
        case DIST:
1088
726k
            for (;;) {
1089
726k
                here = state->distcode[BITS(state->distbits)];
1090
726k
                if ((unsigned)(here.bits) <= bits) break;
1091
250k
                PULLBYTE();
1092
250k
            }
1093
475k
            if ((here.op & 0xf0) == 0) {
1094
1.98k
                last = here;
1095
2.40k
                for (;;) {
1096
2.40k
                    here = state->distcode[last.val +
1097
2.40k
                            (BITS(last.bits + last.op) >> last.bits)];
1098
2.40k
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1099
420
                    PULLBYTE();
1100
420
                }
1101
1.98k
                DROPBITS(last.bits);
1102
1.98k
                state->back += last.bits;
1103
1.98k
            }
1104
475k
            DROPBITS(here.bits);
1105
475k
            state->back += here.bits;
1106
475k
            if (here.op & 64) {
1107
0
                strm->msg = (z_const char *)"invalid distance code";
1108
0
                state->mode = BAD;
1109
0
                break;
1110
0
            }
1111
475k
            state->offset = (unsigned)here.val;
1112
475k
            state->extra = (unsigned)(here.op) & 15;
1113
475k
            state->mode = DISTEXT;
1114
                /* fallthrough */
1115
475k
        case DISTEXT:
1116
475k
            if (state->extra) {
1117
416k
                NEEDBITS(state->extra);
1118
416k
                state->offset += BITS(state->extra);
1119
416k
                DROPBITS(state->extra);
1120
416k
                state->back += state->extra;
1121
416k
            }
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
475k
            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
1130
475k
            state->mode = MATCH;
1131
                /* fallthrough */
1132
524k
        case MATCH:
1133
524k
            if (left == 0) goto inf_leave;
1134
506k
            copy = out - left;
1135
506k
            if (state->offset > copy) {         /* copy from window */
1136
72.1k
                copy = state->offset - copy;
1137
72.1k
                if (copy > state->whave) {
1138
0
                    if (state->sane) {
1139
0
                        strm->msg = (z_const char *)"invalid distance too far back";
1140
0
                        state->mode = BAD;
1141
0
                        break;
1142
0
                    }
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
0
                }
1157
72.1k
                if (copy > state->wnext) {
1158
0
                    copy -= state->wnext;
1159
0
                    from = state->window + (state->wsize - copy);
1160
0
                }
1161
72.1k
                else
1162
72.1k
                    from = state->window + (state->wnext - copy);
1163
72.1k
                if (copy > state->length) copy = state->length;
1164
72.1k
            }
1165
434k
            else {                              /* copy from output */
1166
434k
                from = put - state->offset;
1167
434k
                copy = state->length;
1168
434k
            }
1169
506k
            if (copy > left) copy = left;
1170
506k
            left -= copy;
1171
506k
            state->length -= copy;
1172
5.68M
            do {
1173
5.68M
                *put++ = *from++;
1174
5.68M
            } while (--copy);
1175
506k
            if (state->length == 0) state->mode = LEN;
1176
506k
            break;
1177
5.09M
        case LIT:
1178
5.09M
            if (left == 0) goto inf_leave;
1179
5.04M
            *put++ = (unsigned char)(state->length);
1180
5.04M
            left--;
1181
5.04M
            state->mode = LEN;
1182
5.04M
            break;
1183
46.7k
        case CHECK:
1184
46.7k
            if (state->wrap) {
1185
46.7k
                NEEDBITS(32);
1186
46.7k
                out -= left;
1187
46.7k
                strm->total_out += out;
1188
46.7k
                state->total += out;
1189
46.7k
                if ((state->wrap & 4) && out)
1190
46.7k
                    strm->adler = state->check =
1191
46.7k
                        UPDATE_CHECK(state->check, put - out, out);
1192
46.7k
                out = left;
1193
46.7k
                if ((state->wrap & 4) && (
1194
46.7k
#ifdef GUNZIP
1195
46.7k
                     state->flags ? hold :
1196
46.7k
#endif
1197
46.7k
                     ZSWAP32(hold)) != state->check) {
1198
0
                    strm->msg = (z_const char *)"incorrect data check";
1199
0
                    state->mode = BAD;
1200
0
                    break;
1201
0
                }
1202
46.7k
                INITBITS();
1203
46.7k
                Tracev((stderr, "inflate:   check matches trailer\n"));
1204
46.7k
            }
1205
46.7k
#ifdef GUNZIP
1206
46.7k
            state->mode = LENGTH;
1207
                /* fallthrough */
1208
46.7k
        case LENGTH:
1209
46.7k
            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
46.7k
#endif
1220
46.7k
            state->mode = DONE;
1221
                /* fallthrough */
1222
46.7k
        case DONE:
1223
46.7k
            ret = Z_STREAM_END;
1224
46.7k
            goto inf_leave;
1225
0
        case BAD:
1226
0
            ret = Z_DATA_ERROR;
1227
0
            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
10.9M
        }
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
112k
  inf_leave:
1243
112k
    RESTORE();
1244
112k
    if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
1245
65.3k
            (state->mode < CHECK || flush != Z_FINISH)))
1246
112k
        if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
1247
0
            state->mode = MEM;
1248
0
            return Z_MEM_ERROR;
1249
0
        }
1250
112k
    in -= strm->avail_in;
1251
112k
    out -= strm->avail_out;
1252
112k
    strm->total_in += in;
1253
112k
    strm->total_out += out;
1254
112k
    state->total += out;
1255
112k
    if ((state->wrap & 4) && out)
1256
65.3k
        strm->adler = state->check =
1257
65.3k
            UPDATE_CHECK(state->check, strm->next_out - out, out);
1258
112k
    strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
1259
112k
                      (state->mode == TYPE ? 128 : 0) +
1260
112k
                      (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1261
112k
    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1262
0
        ret = Z_BUF_ERROR;
1263
112k
    return ret;
1264
112k
}
1265
1266
65.3k
int ZEXPORT inflateEnd(z_streamp strm) {
1267
65.3k
    struct inflate_state FAR *state;
1268
65.3k
    if (inflateStateCheck(strm))
1269
0
        return Z_STREAM_ERROR;
1270
65.3k
    state = (struct inflate_state FAR *)strm->state;
1271
65.3k
    if (state->window != Z_NULL) ZFREE(strm, state->window);
1272
65.3k
    ZFREE(strm, strm->state);
1273
65.3k
    strm->state = Z_NULL;
1274
65.3k
    Tracev((stderr, "inflate: end\n"));
1275
65.3k
    return Z_OK;
1276
65.3k
}
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
}