Coverage Report

Created: 2025-06-13 06:55

/work/zlib_ep-prefix/src/zlib_ep/inflate.c
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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
49.6k
local int inflateStateCheck(z_streamp strm) {
95
49.6k
    struct inflate_state FAR *state;
96
49.6k
    if (strm == Z_NULL ||
97
49.6k
        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
98
0
        return 1;
99
49.6k
    state = (struct inflate_state FAR *)strm->state;
100
49.6k
    if (state == Z_NULL || state->strm != strm ||
101
49.6k
        state->mode < HEAD || state->mode > SYNC)
102
0
        return 1;
103
49.6k
    return 0;
104
49.6k
}
105
106
13.3k
int ZEXPORT inflateResetKeep(z_streamp strm) {
107
13.3k
    struct inflate_state FAR *state;
108
109
13.3k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
110
13.3k
    state = (struct inflate_state FAR *)strm->state;
111
13.3k
    strm->total_in = strm->total_out = state->total = 0;
112
13.3k
    strm->msg = Z_NULL;
113
13.3k
    if (state->wrap)        /* to support ill-conceived Java test suite */
114
13.3k
        strm->adler = state->wrap & 1;
115
13.3k
    state->mode = HEAD;
116
13.3k
    state->last = 0;
117
13.3k
    state->havedict = 0;
118
13.3k
    state->flags = -1;
119
13.3k
    state->dmax = 32768U;
120
13.3k
    state->head = Z_NULL;
121
13.3k
    state->hold = 0;
122
13.3k
    state->bits = 0;
123
13.3k
    state->lencode = state->distcode = state->next = state->codes;
124
13.3k
    state->sane = 1;
125
13.3k
    state->back = -1;
126
13.3k
    Tracev((stderr, "inflate: reset\n"));
127
13.3k
    return Z_OK;
128
13.3k
}
129
130
13.3k
int ZEXPORT inflateReset(z_streamp strm) {
131
13.3k
    struct inflate_state FAR *state;
132
133
13.3k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
134
13.3k
    state = (struct inflate_state FAR *)strm->state;
135
13.3k
    state->wsize = 0;
136
13.3k
    state->whave = 0;
137
13.3k
    state->wnext = 0;
138
13.3k
    return inflateResetKeep(strm);
139
13.3k
}
140
141
9.59k
int ZEXPORT inflateReset2(z_streamp strm, int windowBits) {
142
9.59k
    int wrap;
143
9.59k
    struct inflate_state FAR *state;
144
145
    /* get the state */
146
9.59k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
147
9.59k
    state = (struct inflate_state FAR *)strm->state;
148
149
    /* extract wrap request from windowBits parameter */
150
9.59k
    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
9.59k
    else {
157
9.59k
        wrap = (windowBits >> 4) + 5;
158
9.59k
#ifdef GUNZIP
159
9.59k
        if (windowBits < 48)
160
9.59k
            windowBits &= 15;
161
9.59k
#endif
162
9.59k
    }
163
164
    /* set number of window bits, free window if different */
165
9.59k
    if (windowBits && (windowBits < 8 || windowBits > 15))
166
0
        return Z_STREAM_ERROR;
167
9.59k
    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
9.59k
    state->wrap = wrap;
174
9.59k
    state->wbits = (unsigned)windowBits;
175
9.59k
    return inflateReset(strm);
176
9.59k
}
177
178
int ZEXPORT inflateInit2_(z_streamp strm, int windowBits,
179
9.59k
                          const char *version, int stream_size) {
180
9.59k
    int ret;
181
9.59k
    struct inflate_state FAR *state;
182
183
9.59k
    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
184
9.59k
        stream_size != (int)(sizeof(z_stream)))
185
0
        return Z_VERSION_ERROR;
186
9.59k
    if (strm == Z_NULL) return Z_STREAM_ERROR;
187
9.59k
    strm->msg = Z_NULL;                 /* in case we return an error */
188
9.59k
    if (strm->zalloc == (alloc_func)0) {
189
#ifdef Z_SOLO
190
        return Z_STREAM_ERROR;
191
#else
192
9.59k
        strm->zalloc = zcalloc;
193
9.59k
        strm->opaque = (voidpf)0;
194
9.59k
#endif
195
9.59k
    }
196
9.59k
    if (strm->zfree == (free_func)0)
197
#ifdef Z_SOLO
198
        return Z_STREAM_ERROR;
199
#else
200
9.59k
        strm->zfree = zcfree;
201
9.59k
#endif
202
9.59k
    state = (struct inflate_state FAR *)
203
9.59k
            ZALLOC(strm, 1, sizeof(struct inflate_state));
204
9.59k
    if (state == Z_NULL) return Z_MEM_ERROR;
205
9.59k
    Tracev((stderr, "inflate: allocated\n"));
206
9.59k
    strm->state = (struct internal_state FAR *)state;
207
9.59k
    state->strm = strm;
208
9.59k
    state->window = Z_NULL;
209
9.59k
    state->mode = HEAD;     /* to pass state test in inflateReset2() */
210
9.59k
    ret = inflateReset2(strm, windowBits);
211
9.59k
    if (ret != Z_OK) {
212
0
        ZFREE(strm, state);
213
0
        strm->state = Z_NULL;
214
0
    }
215
9.59k
    return ret;
216
9.59k
}
217
218
int ZEXPORT inflateInit_(z_streamp strm, const char *version,
219
0
                         int stream_size) {
220
0
    return inflateInit2_(strm, DEF_WBITS, version, stream_size);
221
0
}
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
1.06k
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
1.06k
#   include "inffixed.h"
286
1.06k
#endif /* BUILDFIXED */
287
1.06k
    state->lencode = lenfix;
288
1.06k
    state->lenbits = 9;
289
1.06k
    state->distcode = distfix;
290
1.06k
    state->distbits = 5;
291
1.06k
}
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
384
local int updatewindow(z_streamp strm, const Bytef *end, unsigned copy) {
369
384
    struct inflate_state FAR *state;
370
384
    unsigned dist;
371
372
384
    state = (struct inflate_state FAR *)strm->state;
373
374
    /* if it hasn't been done already, allocate space for the window */
375
384
    if (state->window == Z_NULL) {
376
384
        state->window = (unsigned char FAR *)
377
384
                        ZALLOC(strm, 1U << state->wbits,
378
384
                               sizeof(unsigned char));
379
384
        if (state->window == Z_NULL) return 1;
380
384
    }
381
382
    /* if window not in use yet, initialize */
383
384
    if (state->wsize == 0) {
384
384
        state->wsize = 1U << state->wbits;
385
384
        state->wnext = 0;
386
384
        state->whave = 0;
387
384
    }
388
389
    /* copy state->wsize or less output bytes into the circular window */
390
384
    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
384
    else {
396
384
        dist = state->wsize - state->wnext;
397
384
        if (dist > copy) dist = copy;
398
384
        zmemcpy(state->window + state->wnext, end - copy, dist);
399
384
        copy -= dist;
400
384
        if (copy) {
401
0
            zmemcpy(state->window, end - copy, copy);
402
0
            state->wnext = copy;
403
0
            state->whave = state->wsize;
404
0
        }
405
384
        else {
406
384
            state->wnext += dist;
407
384
            if (state->wnext == state->wsize) state->wnext = 0;
408
384
            if (state->whave < state->wsize) state->whave += dist;
409
384
        }
410
384
    }
411
384
    return 0;
412
384
}
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
1.42k
    (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
3.23k
    do { \
428
3.23k
        hbuf[0] = (unsigned char)(word); \
429
3.23k
        hbuf[1] = (unsigned char)((word) >> 8); \
430
3.23k
        check = crc32(check, hbuf, 2); \
431
3.23k
    } while (0)
432
433
#  define CRC4(check, word) \
434
400
    do { \
435
400
        hbuf[0] = (unsigned char)(word); \
436
400
        hbuf[1] = (unsigned char)((word) >> 8); \
437
400
        hbuf[2] = (unsigned char)((word) >> 16); \
438
400
        hbuf[3] = (unsigned char)((word) >> 24); \
439
400
        check = crc32(check, hbuf, 4); \
440
400
    } while (0)
441
#endif
442
443
/* Load registers with state in inflate() for speed */
444
#define LOAD() \
445
5.64k
    do { \
446
5.64k
        put = strm->next_out; \
447
5.64k
        left = strm->avail_out; \
448
5.64k
        next = strm->next_in; \
449
5.64k
        have = strm->avail_in; \
450
5.64k
        hold = state->hold; \
451
5.64k
        bits = state->bits; \
452
5.64k
    } while (0)
453
454
/* Restore state from registers in inflate() */
455
#define RESTORE() \
456
5.64k
    do { \
457
5.64k
        strm->next_out = put; \
458
5.64k
        strm->avail_out = left; \
459
5.64k
        strm->next_in = next; \
460
5.64k
        strm->avail_in = have; \
461
5.64k
        state->hold = hold; \
462
5.64k
        state->bits = bits; \
463
5.64k
    } while (0)
464
465
/* Clear the input bit accumulator */
466
#define INITBITS() \
467
10.4k
    do { \
468
10.4k
        hold = 0; \
469
10.4k
        bits = 0; \
470
10.4k
    } 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
215k
    do { \
476
215k
        if (have == 0) goto inf_leave; \
477
215k
        have--; \
478
215k
        hold += (unsigned long)(*next++) << bits; \
479
215k
        bits += 8; \
480
215k
    } 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
55.6k
    do { \
486
109k
        while (bits < (unsigned)(n)) \
487
55.6k
            PULLBYTE(); \
488
55.6k
    } while (0)
489
490
/* Return the low n bits of the bit accumulator (n < 16) */
491
#define BITS(n) \
492
543k
    ((unsigned)hold & ((1U << (n)) - 1))
493
494
/* Remove n bits from the bit accumulator */
495
#define DROPBITS(n) \
496
380k
    do { \
497
380k
        hold >>= (n); \
498
380k
        bits -= (unsigned)(n); \
499
380k
    } while (0)
500
501
/* Remove zero to seven bits as needed to go to a byte boundary */
502
#define BYTEBITS() \
503
1.16k
    do { \
504
1.16k
        hold >>= bits & 7; \
505
1.16k
        bits -= bits & 7; \
506
1.16k
    } 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
3.75k
int ZEXPORT inflate(z_streamp strm, int flush) {
591
3.75k
    struct inflate_state FAR *state;
592
3.75k
    z_const unsigned char FAR *next;    /* next input */
593
3.75k
    unsigned char FAR *put;     /* next output */
594
3.75k
    unsigned have, left;        /* available input and output */
595
3.75k
    unsigned long hold;         /* bit buffer */
596
3.75k
    unsigned bits;              /* bits in bit buffer */
597
3.75k
    unsigned in, out;           /* save starting available input and output */
598
3.75k
    unsigned copy;              /* number of stored or match bytes to copy */
599
3.75k
    unsigned char FAR *from;    /* where to copy match bytes from */
600
3.75k
    code here;                  /* current decoding table entry */
601
3.75k
    code last;                  /* parent table entry */
602
3.75k
    unsigned len;               /* length to copy for repeats, bits to drop */
603
3.75k
    int ret;                    /* return code */
604
3.75k
#ifdef GUNZIP
605
3.75k
    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
606
3.75k
#endif
607
3.75k
    static const unsigned short order[19] = /* permutation of code lengths */
608
3.75k
        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
609
610
3.75k
    if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
611
3.75k
        (strm->next_in == Z_NULL && strm->avail_in != 0))
612
0
        return Z_STREAM_ERROR;
613
614
3.75k
    state = (struct inflate_state FAR *)strm->state;
615
3.75k
    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
616
3.75k
    LOAD();
617
3.75k
    in = have;
618
3.75k
    out = left;
619
3.75k
    ret = Z_OK;
620
3.75k
    for (;;)
621
257k
        switch (state->mode) {
622
3.75k
        case HEAD:
623
3.75k
            if (state->wrap == 0) {
624
0
                state->mode = TYPEDO;
625
0
                break;
626
0
            }
627
3.75k
            NEEDBITS(16);
628
3.74k
#ifdef GUNZIP
629
3.74k
            if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
630
2.11k
                if (state->wbits == 0)
631
0
                    state->wbits = 15;
632
2.11k
                state->check = crc32(0L, Z_NULL, 0);
633
2.11k
                CRC2(state->check, hold);
634
2.11k
                INITBITS();
635
2.11k
                state->mode = FLAGS;
636
2.11k
                break;
637
2.11k
            }
638
1.62k
            if (state->head != Z_NULL)
639
0
                state->head->done = -1;
640
1.62k
            if (!(state->wrap & 1) ||   /* check if zlib header allowed */
641
#else
642
            if (
643
#endif
644
1.62k
                ((BITS(8) << 8) + (hold >> 8)) % 31) {
645
1.49k
                strm->msg = (char *)"incorrect header check";
646
1.49k
                state->mode = BAD;
647
1.49k
                break;
648
1.49k
            }
649
132
            if (BITS(4) != Z_DEFLATED) {
650
24
                strm->msg = (char *)"unknown compression method";
651
24
                state->mode = BAD;
652
24
                break;
653
24
            }
654
108
            DROPBITS(4);
655
108
            len = BITS(4) + 8;
656
108
            if (state->wbits == 0)
657
0
                state->wbits = len;
658
108
            if (len > 15 || len > state->wbits) {
659
8
                strm->msg = (char *)"invalid window size";
660
8
                state->mode = BAD;
661
8
                break;
662
8
            }
663
100
            state->dmax = 1U << len;
664
100
            state->flags = 0;               /* indicate zlib header */
665
100
            Tracev((stderr, "inflate:   zlib header ok\n"));
666
100
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
667
100
            state->mode = hold & 0x200 ? DICTID : TYPE;
668
100
            INITBITS();
669
100
            break;
670
0
#ifdef GUNZIP
671
2.11k
        case FLAGS:
672
2.11k
            NEEDBITS(16);
673
2.11k
            state->flags = (int)(hold);
674
2.11k
            if ((state->flags & 0xff) != Z_DEFLATED) {
675
8
                strm->msg = (char *)"unknown compression method";
676
8
                state->mode = BAD;
677
8
                break;
678
8
            }
679
2.10k
            if (state->flags & 0xe000) {
680
8
                strm->msg = (char *)"unknown header flags set";
681
8
                state->mode = BAD;
682
8
                break;
683
8
            }
684
2.10k
            if (state->head != Z_NULL)
685
0
                state->head->text = (int)((hold >> 8) & 1);
686
2.10k
            if ((state->flags & 0x0200) && (state->wrap & 4))
687
400
                CRC2(state->check, hold);
688
2.10k
            INITBITS();
689
2.10k
            state->mode = TIME;
690
                /* fallthrough */
691
2.10k
        case TIME:
692
2.10k
            NEEDBITS(32);
693
2.08k
            if (state->head != Z_NULL)
694
0
                state->head->time = hold;
695
2.08k
            if ((state->flags & 0x0200) && (state->wrap & 4))
696
400
                CRC4(state->check, hold);
697
2.08k
            INITBITS();
698
2.08k
            state->mode = OS;
699
                /* fallthrough */
700
2.08k
        case OS:
701
2.08k
            NEEDBITS(16);
702
2.08k
            if (state->head != Z_NULL) {
703
0
                state->head->xflags = (int)(hold & 0xff);
704
0
                state->head->os = (int)(hold >> 8);
705
0
            }
706
2.08k
            if ((state->flags & 0x0200) && (state->wrap & 4))
707
400
                CRC2(state->check, hold);
708
2.08k
            INITBITS();
709
2.08k
            state->mode = EXLEN;
710
                /* fallthrough */
711
2.08k
        case EXLEN:
712
2.08k
            if (state->flags & 0x0400) {
713
388
                NEEDBITS(16);
714
388
                state->length = (unsigned)(hold);
715
388
                if (state->head != Z_NULL)
716
0
                    state->head->extra_len = (unsigned)hold;
717
388
                if ((state->flags & 0x0200) && (state->wrap & 4))
718
320
                    CRC2(state->check, hold);
719
388
                INITBITS();
720
388
            }
721
1.70k
            else if (state->head != Z_NULL)
722
0
                state->head->extra = Z_NULL;
723
2.08k
            state->mode = EXTRA;
724
                /* fallthrough */
725
2.08k
        case EXTRA:
726
2.08k
            if (state->flags & 0x0400) {
727
388
                copy = state->length;
728
388
                if (copy > have) copy = have;
729
388
                if (copy) {
730
376
                    if (state->head != Z_NULL &&
731
376
                        state->head->extra != Z_NULL &&
732
376
                        (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
376
                    if ((state->flags & 0x0200) && (state->wrap & 4))
739
308
                        state->check = crc32(state->check, next, copy);
740
376
                    have -= copy;
741
376
                    next += copy;
742
376
                    state->length -= copy;
743
376
                }
744
388
                if (state->length) goto inf_leave;
745
388
            }
746
2.08k
            state->length = 0;
747
2.08k
            state->mode = NAME;
748
                /* fallthrough */
749
2.08k
        case NAME:
750
2.08k
            if (state->flags & 0x0800) {
751
460
                if (have == 0) goto inf_leave;
752
452
                copy = 0;
753
53.9k
                do {
754
53.9k
                    len = (unsigned)(next[copy++]);
755
53.9k
                    if (state->head != Z_NULL &&
756
53.9k
                            state->head->name != Z_NULL &&
757
53.9k
                            state->length < state->head->name_max)
758
0
                        state->head->name[state->length++] = (Bytef)len;
759
53.9k
                } while (len && copy < have);
760
452
                if ((state->flags & 0x0200) && (state->wrap & 4))
761
392
                    state->check = crc32(state->check, next, copy);
762
452
                have -= copy;
763
452
                next += copy;
764
452
                if (len) goto inf_leave;
765
452
            }
766
1.62k
            else if (state->head != Z_NULL)
767
0
                state->head->name = Z_NULL;
768
2.06k
            state->length = 0;
769
2.06k
            state->mode = COMMENT;
770
                /* fallthrough */
771
2.06k
        case COMMENT:
772
2.06k
            if (state->flags & 0x1000) {
773
440
                if (have == 0) goto inf_leave;
774
432
                copy = 0;
775
36.5k
                do {
776
36.5k
                    len = (unsigned)(next[copy++]);
777
36.5k
                    if (state->head != Z_NULL &&
778
36.5k
                            state->head->comment != Z_NULL &&
779
36.5k
                            state->length < state->head->comm_max)
780
0
                        state->head->comment[state->length++] = (Bytef)len;
781
36.5k
                } while (len && copy < have);
782
432
                if ((state->flags & 0x0200) && (state->wrap & 4))
783
372
                    state->check = crc32(state->check, next, copy);
784
432
                have -= copy;
785
432
                next += copy;
786
432
                if (len) goto inf_leave;
787
432
            }
788
1.62k
            else if (state->head != Z_NULL)
789
0
                state->head->comment = Z_NULL;
790
2.02k
            state->mode = HCRC;
791
                /* fallthrough */
792
2.02k
        case HCRC:
793
2.02k
            if (state->flags & 0x0200) {
794
348
                NEEDBITS(16);
795
332
                if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
796
320
                    strm->msg = (char *)"header crc mismatch";
797
320
                    state->mode = BAD;
798
320
                    break;
799
320
                }
800
12
                INITBITS();
801
12
            }
802
1.69k
            if (state->head != Z_NULL) {
803
0
                state->head->hcrc = (int)((state->flags >> 9) & 1);
804
0
                state->head->done = 1;
805
0
            }
806
1.69k
            strm->adler = state->check = crc32(0L, Z_NULL, 0);
807
1.69k
            state->mode = TYPE;
808
1.69k
            break;
809
0
#endif
810
8
        case DICTID:
811
8
            NEEDBITS(32);
812
8
            strm->adler = state->check = ZSWAP32(hold);
813
8
            INITBITS();
814
8
            state->mode = DICT;
815
                /* fallthrough */
816
8
        case DICT:
817
8
            if (state->havedict == 0) {
818
8
                RESTORE();
819
8
                return Z_NEED_DICT;
820
8
            }
821
0
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
822
0
            state->mode = TYPE;
823
                /* fallthrough */
824
3.36k
        case TYPE:
825
3.36k
            if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
826
                /* fallthrough */
827
3.36k
        case TYPEDO:
828
3.36k
            if (state->last) {
829
788
                BYTEBITS();
830
788
                state->mode = CHECK;
831
788
                break;
832
788
            }
833
2.58k
            NEEDBITS(3);
834
2.57k
            state->last = BITS(1);
835
2.57k
            DROPBITS(1);
836
2.57k
            switch (BITS(2)) {
837
380
            case 0:                             /* stored block */
838
380
                Tracev((stderr, "inflate:     stored block%s\n",
839
380
                        state->last ? " (last)" : ""));
840
380
                state->mode = STORED;
841
380
                break;
842
1.06k
            case 1:                             /* fixed block */
843
1.06k
                fixedtables(state);
844
1.06k
                Tracev((stderr, "inflate:     fixed codes block%s\n",
845
1.06k
                        state->last ? " (last)" : ""));
846
1.06k
                state->mode = LEN_;             /* decode codes */
847
1.06k
                if (flush == Z_TREES) {
848
0
                    DROPBITS(2);
849
0
                    goto inf_leave;
850
0
                }
851
1.06k
                break;
852
1.11k
            case 2:                             /* dynamic block */
853
1.11k
                Tracev((stderr, "inflate:     dynamic codes block%s\n",
854
1.11k
                        state->last ? " (last)" : ""));
855
1.11k
                state->mode = TABLE;
856
1.11k
                break;
857
12
            case 3:
858
12
                strm->msg = (char *)"invalid block type";
859
12
                state->mode = BAD;
860
2.57k
            }
861
2.57k
            DROPBITS(2);
862
2.57k
            break;
863
380
        case STORED:
864
380
            BYTEBITS();                         /* go to byte boundary */
865
380
            NEEDBITS(32);
866
348
            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
867
36
                strm->msg = (char *)"invalid stored block lengths";
868
36
                state->mode = BAD;
869
36
                break;
870
36
            }
871
312
            state->length = (unsigned)hold & 0xffff;
872
312
            Tracev((stderr, "inflate:       stored length %u\n",
873
312
                    state->length));
874
312
            INITBITS();
875
312
            state->mode = COPY_;
876
312
            if (flush == Z_TREES) goto inf_leave;
877
                /* fallthrough */
878
312
        case COPY_:
879
312
            state->mode = COPY;
880
                /* fallthrough */
881
464
        case COPY:
882
464
            copy = state->length;
883
464
            if (copy) {
884
184
                if (copy > have) copy = have;
885
184
                if (copy > left) copy = left;
886
184
                if (copy == 0) goto inf_leave;
887
152
                zmemcpy(put, next, copy);
888
152
                have -= copy;
889
152
                next += copy;
890
152
                left -= copy;
891
152
                put += copy;
892
152
                state->length -= copy;
893
152
                break;
894
184
            }
895
280
            Tracev((stderr, "inflate:       stored end\n"));
896
280
            state->mode = TYPE;
897
280
            break;
898
1.11k
        case TABLE:
899
1.11k
            NEEDBITS(14);
900
1.10k
            state->nlen = BITS(5) + 257;
901
1.10k
            DROPBITS(5);
902
1.10k
            state->ndist = BITS(5) + 1;
903
1.10k
            DROPBITS(5);
904
1.10k
            state->ncode = BITS(4) + 4;
905
1.10k
            DROPBITS(4);
906
1.10k
#ifndef PKZIP_BUG_WORKAROUND
907
1.10k
            if (state->nlen > 286 || state->ndist > 30) {
908
20
                strm->msg = (char *)"too many length or distance symbols";
909
20
                state->mode = BAD;
910
20
                break;
911
20
            }
912
1.08k
#endif
913
1.08k
            Tracev((stderr, "inflate:       table sizes ok\n"));
914
1.08k
            state->have = 0;
915
1.08k
            state->mode = LENLENS;
916
                /* fallthrough */
917
1.08k
        case LENLENS:
918
17.1k
            while (state->have < state->ncode) {
919
16.0k
                NEEDBITS(3);
920
16.0k
                state->lens[order[state->have++]] = (unsigned short)BITS(3);
921
16.0k
                DROPBITS(3);
922
16.0k
            }
923
5.48k
            while (state->have < 19)
924
4.41k
                state->lens[order[state->have++]] = 0;
925
1.07k
            state->next = state->codes;
926
1.07k
            state->lencode = (const code FAR *)(state->next);
927
1.07k
            state->lenbits = 7;
928
1.07k
            ret = inflate_table(CODES, state->lens, 19, &(state->next),
929
1.07k
                                &(state->lenbits), state->work);
930
1.07k
            if (ret) {
931
140
                strm->msg = (char *)"invalid code lengths set";
932
140
                state->mode = BAD;
933
140
                break;
934
140
            }
935
932
            Tracev((stderr, "inflate:       code lengths ok\n"));
936
932
            state->have = 0;
937
932
            state->mode = CODELENS;
938
                /* fallthrough */
939
932
        case CODELENS:
940
190k
            while (state->have < state->nlen + state->ndist) {
941
245k
                for (;;) {
942
245k
                    here = state->lencode[BITS(state->lenbits)];
943
245k
                    if ((unsigned)(here.bits) <= bits) break;
944
55.8k
                    PULLBYTE();
945
55.8k
                }
946
189k
                if (here.val < 16) {
947
179k
                    DROPBITS(here.bits);
948
179k
                    state->lens[state->have++] = here.val;
949
179k
                }
950
10.4k
                else {
951
10.4k
                    if (here.val == 16) {
952
5.52k
                        NEEDBITS(here.bits + 2);
953
5.52k
                        DROPBITS(here.bits);
954
5.52k
                        if (state->have == 0) {
955
8
                            strm->msg = (char *)"invalid bit length repeat";
956
8
                            state->mode = BAD;
957
8
                            break;
958
8
                        }
959
5.52k
                        len = state->lens[state->have - 1];
960
5.52k
                        copy = 3 + BITS(2);
961
5.52k
                        DROPBITS(2);
962
5.52k
                    }
963
4.94k
                    else if (here.val == 17) {
964
4.33k
                        NEEDBITS(here.bits + 3);
965
4.32k
                        DROPBITS(here.bits);
966
4.32k
                        len = 0;
967
4.32k
                        copy = 3 + BITS(3);
968
4.32k
                        DROPBITS(3);
969
4.32k
                    }
970
612
                    else {
971
612
                        NEEDBITS(here.bits + 7);
972
604
                        DROPBITS(here.bits);
973
604
                        len = 0;
974
604
                        copy = 11 + BITS(7);
975
604
                        DROPBITS(7);
976
604
                    }
977
10.4k
                    if (state->have + copy > state->nlen + state->ndist) {
978
28
                        strm->msg = (char *)"invalid bit length repeat";
979
28
                        state->mode = BAD;
980
28
                        break;
981
28
                    }
982
81.8k
                    while (copy--)
983
71.4k
                        state->lens[state->have++] = (unsigned short)len;
984
10.4k
                }
985
189k
            }
986
987
            /* handle error breaks in while */
988
908
            if (state->mode == BAD) break;
989
990
            /* check for end-of-block code (better have one) */
991
872
            if (state->lens[256] == 0) {
992
20
                strm->msg = (char *)"invalid code -- missing end-of-block";
993
20
                state->mode = BAD;
994
20
                break;
995
20
            }
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
852
            state->next = state->codes;
1001
852
            state->lencode = (const code FAR *)(state->next);
1002
852
            state->lenbits = 9;
1003
852
            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1004
852
                                &(state->lenbits), state->work);
1005
852
            if (ret) {
1006
96
                strm->msg = (char *)"invalid literal/lengths set";
1007
96
                state->mode = BAD;
1008
96
                break;
1009
96
            }
1010
756
            state->distcode = (const code FAR *)(state->next);
1011
756
            state->distbits = 6;
1012
756
            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1013
756
                            &(state->next), &(state->distbits), state->work);
1014
756
            if (ret) {
1015
84
                strm->msg = (char *)"invalid distances set";
1016
84
                state->mode = BAD;
1017
84
                break;
1018
84
            }
1019
672
            Tracev((stderr, "inflate:       codes ok\n"));
1020
672
            state->mode = LEN_;
1021
672
            if (flush == Z_TREES) goto inf_leave;
1022
                /* fallthrough */
1023
1.73k
        case LEN_:
1024
1.73k
            state->mode = LEN;
1025
                /* fallthrough */
1026
129k
        case LEN:
1027
129k
            if (have >= 6 && left >= 258) {
1028
1.88k
                RESTORE();
1029
1.88k
                inflate_fast(strm, out);
1030
1.88k
                LOAD();
1031
1.88k
                if (state->mode == TYPE)
1032
464
                    state->back = -1;
1033
1.88k
                break;
1034
1.88k
            }
1035
127k
            state->back = 0;
1036
226k
            for (;;) {
1037
226k
                here = state->lencode[BITS(state->lenbits)];
1038
226k
                if ((unsigned)(here.bits) <= bits) break;
1039
98.8k
                PULLBYTE();
1040
98.8k
            }
1041
127k
            if (here.op && (here.op & 0xf0) == 0) {
1042
2.79k
                last = here;
1043
3.44k
                for (;;) {
1044
3.44k
                    here = state->lencode[last.val +
1045
3.44k
                            (BITS(last.bits + last.op) >> last.bits)];
1046
3.44k
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1047
656
                    PULLBYTE();
1048
656
                }
1049
2.79k
                DROPBITS(last.bits);
1050
2.79k
                state->back += last.bits;
1051
2.79k
            }
1052
127k
            DROPBITS(here.bits);
1053
127k
            state->back += here.bits;
1054
127k
            state->length = (unsigned)here.val;
1055
127k
            if ((int)(here.op) == 0) {
1056
114k
                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1057
114k
                        "inflate:         literal '%c'\n" :
1058
114k
                        "inflate:         literal 0x%02x\n", here.val));
1059
114k
                state->mode = LIT;
1060
114k
                break;
1061
114k
            }
1062
13.0k
            if (here.op & 32) {
1063
840
                Tracevv((stderr, "inflate:         end of block\n"));
1064
840
                state->back = -1;
1065
840
                state->mode = TYPE;
1066
840
                break;
1067
840
            }
1068
12.2k
            if (here.op & 64) {
1069
8
                strm->msg = (char *)"invalid literal/length code";
1070
8
                state->mode = BAD;
1071
8
                break;
1072
8
            }
1073
12.1k
            state->extra = (unsigned)(here.op) & 15;
1074
12.1k
            state->mode = LENEXT;
1075
                /* fallthrough */
1076
12.1k
        case LENEXT:
1077
12.1k
            if (state->extra) {
1078
1.38k
                NEEDBITS(state->extra);
1079
1.38k
                state->length += BITS(state->extra);
1080
1.38k
                DROPBITS(state->extra);
1081
1.38k
                state->back += state->extra;
1082
1.38k
            }
1083
12.1k
            Tracevv((stderr, "inflate:         length %u\n", state->length));
1084
12.1k
            state->was = state->length;
1085
12.1k
            state->mode = DIST;
1086
                /* fallthrough */
1087
12.1k
        case DIST:
1088
18.0k
            for (;;) {
1089
18.0k
                here = state->distcode[BITS(state->distbits)];
1090
18.0k
                if ((unsigned)(here.bits) <= bits) break;
1091
5.92k
                PULLBYTE();
1092
5.92k
            }
1093
12.1k
            if ((here.op & 0xf0) == 0) {
1094
396
                last = here;
1095
516
                for (;;) {
1096
516
                    here = state->distcode[last.val +
1097
516
                            (BITS(last.bits + last.op) >> last.bits)];
1098
516
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1099
124
                    PULLBYTE();
1100
124
                }
1101
392
                DROPBITS(last.bits);
1102
392
                state->back += last.bits;
1103
392
            }
1104
12.1k
            DROPBITS(here.bits);
1105
12.1k
            state->back += here.bits;
1106
12.1k
            if (here.op & 64) {
1107
12
                strm->msg = (char *)"invalid distance code";
1108
12
                state->mode = BAD;
1109
12
                break;
1110
12
            }
1111
12.1k
            state->offset = (unsigned)here.val;
1112
12.1k
            state->extra = (unsigned)(here.op) & 15;
1113
12.1k
            state->mode = DISTEXT;
1114
                /* fallthrough */
1115
12.1k
        case DISTEXT:
1116
12.1k
            if (state->extra) {
1117
11.4k
                NEEDBITS(state->extra);
1118
11.4k
                state->offset += BITS(state->extra);
1119
11.4k
                DROPBITS(state->extra);
1120
11.4k
                state->back += state->extra;
1121
11.4k
            }
1122
#ifdef INFLATE_STRICT
1123
            if (state->offset > state->dmax) {
1124
                strm->msg = (char *)"invalid distance too far back";
1125
                state->mode = BAD;
1126
                break;
1127
            }
1128
#endif
1129
12.1k
            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
1130
12.1k
            state->mode = MATCH;
1131
                /* fallthrough */
1132
12.2k
        case MATCH:
1133
12.2k
            if (left == 0) goto inf_leave;
1134
12.1k
            copy = out - left;
1135
12.1k
            if (state->offset > copy) {         /* copy from window */
1136
92
                copy = state->offset - copy;
1137
92
                if (copy > state->whave) {
1138
92
                    if (state->sane) {
1139
92
                        strm->msg = (char *)"invalid distance too far back";
1140
92
                        state->mode = BAD;
1141
92
                        break;
1142
92
                    }
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
92
                }
1157
0
                if (copy > state->wnext) {
1158
0
                    copy -= state->wnext;
1159
0
                    from = state->window + (state->wsize - copy);
1160
0
                }
1161
0
                else
1162
0
                    from = state->window + (state->wnext - copy);
1163
0
                if (copy > state->length) copy = state->length;
1164
0
            }
1165
12.0k
            else {                              /* copy from output */
1166
12.0k
                from = put - state->offset;
1167
12.0k
                copy = state->length;
1168
12.0k
            }
1169
12.0k
            if (copy > left) copy = left;
1170
12.0k
            left -= copy;
1171
12.0k
            state->length -= copy;
1172
100k
            do {
1173
100k
                *put++ = *from++;
1174
100k
            } while (--copy);
1175
12.0k
            if (state->length == 0) state->mode = LEN;
1176
12.0k
            break;
1177
114k
        case LIT:
1178
114k
            if (left == 0) goto inf_leave;
1179
114k
            *put++ = (unsigned char)(state->length);
1180
114k
            left--;
1181
114k
            state->mode = LEN;
1182
114k
            break;
1183
788
        case CHECK:
1184
788
            if (state->wrap) {
1185
788
                NEEDBITS(32);
1186
752
                out -= left;
1187
752
                strm->total_out += out;
1188
752
                state->total += out;
1189
752
                if ((state->wrap & 4) && out)
1190
752
                    strm->adler = state->check =
1191
752
                        UPDATE_CHECK(state->check, put - out, out);
1192
752
                out = left;
1193
752
                if ((state->wrap & 4) && (
1194
752
#ifdef GUNZIP
1195
752
                     state->flags ? hold :
1196
752
#endif
1197
752
                     ZSWAP32(hold)) != state->check) {
1198
136
                    strm->msg = (char *)"incorrect data check";
1199
136
                    state->mode = BAD;
1200
136
                    break;
1201
136
                }
1202
616
                INITBITS();
1203
616
                Tracev((stderr, "inflate:   check matches trailer\n"));
1204
616
            }
1205
616
#ifdef GUNZIP
1206
616
            state->mode = LENGTH;
1207
                /* fallthrough */
1208
616
        case LENGTH:
1209
616
            if (state->wrap && state->flags) {
1210
616
                NEEDBITS(32);
1211
608
                if ((state->wrap & 4) && hold != (state->total & 0xffffffff)) {
1212
28
                    strm->msg = (char *)"incorrect length check";
1213
28
                    state->mode = BAD;
1214
28
                    break;
1215
28
                }
1216
580
                INITBITS();
1217
580
                Tracev((stderr, "inflate:   length matches trailer\n"));
1218
580
            }
1219
580
#endif
1220
580
            state->mode = DONE;
1221
                /* fallthrough */
1222
580
        case DONE:
1223
580
            ret = Z_STREAM_END;
1224
580
            goto inf_leave;
1225
2.64k
        case BAD:
1226
2.64k
            ret = Z_DATA_ERROR;
1227
2.64k
            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
257k
        }
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
3.74k
  inf_leave:
1243
3.74k
    RESTORE();
1244
3.74k
    if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
1245
3.74k
            (state->mode < CHECK || flush != Z_FINISH)))
1246
384
        if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
1247
0
            state->mode = MEM;
1248
0
            return Z_MEM_ERROR;
1249
0
        }
1250
3.74k
    in -= strm->avail_in;
1251
3.74k
    out -= strm->avail_out;
1252
3.74k
    strm->total_in += in;
1253
3.74k
    strm->total_out += out;
1254
3.74k
    state->total += out;
1255
3.74k
    if ((state->wrap & 4) && out)
1256
676
        strm->adler = state->check =
1257
676
            UPDATE_CHECK(state->check, strm->next_out - out, out);
1258
3.74k
    strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
1259
3.74k
                      (state->mode == TYPE ? 128 : 0) +
1260
3.74k
                      (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1261
3.74k
    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1262
524
        ret = Z_BUF_ERROR;
1263
3.74k
    return ret;
1264
3.74k
}
1265
1266
9.59k
int ZEXPORT inflateEnd(z_streamp strm) {
1267
9.59k
    struct inflate_state FAR *state;
1268
9.59k
    if (inflateStateCheck(strm))
1269
0
        return Z_STREAM_ERROR;
1270
9.59k
    state = (struct inflate_state FAR *)strm->state;
1271
9.59k
    if (state->window != Z_NULL) ZFREE(strm, state->window);
1272
9.59k
    ZFREE(strm, strm->state);
1273
9.59k
    strm->state = Z_NULL;
1274
9.59k
    Tracev((stderr, "inflate: end\n"));
1275
9.59k
    return Z_OK;
1276
9.59k
}
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
}