Coverage Report

Created: 2025-01-28 06:17

/src/mupdf/thirdparty/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
3.78M
local int inflateStateCheck(z_streamp strm) {
95
3.78M
    struct inflate_state FAR *state;
96
3.78M
    if (strm == Z_NULL ||
97
3.78M
        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
98
0
        return 1;
99
3.78M
    state = (struct inflate_state FAR *)strm->state;
100
3.78M
    if (state == Z_NULL || state->strm != strm ||
101
3.78M
        state->mode < HEAD || state->mode > SYNC)
102
0
        return 1;
103
3.78M
    return 0;
104
3.78M
}
105
106
78.1k
int ZEXPORT inflateResetKeep(z_streamp strm) {
107
78.1k
    struct inflate_state FAR *state;
108
109
78.1k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
110
78.1k
    state = (struct inflate_state FAR *)strm->state;
111
78.1k
    strm->total_in = strm->total_out = state->total = 0;
112
78.1k
    strm->msg = Z_NULL;
113
78.1k
    if (state->wrap)        /* to support ill-conceived Java test suite */
114
78.1k
        strm->adler = state->wrap & 1;
115
78.1k
    state->mode = HEAD;
116
78.1k
    state->last = 0;
117
78.1k
    state->havedict = 0;
118
78.1k
    state->flags = -1;
119
78.1k
    state->dmax = 32768U;
120
78.1k
    state->head = Z_NULL;
121
78.1k
    state->hold = 0;
122
78.1k
    state->bits = 0;
123
78.1k
    state->lencode = state->distcode = state->next = state->codes;
124
78.1k
    state->sane = 1;
125
78.1k
    state->back = -1;
126
78.1k
    Tracev((stderr, "inflate: reset\n"));
127
78.1k
    return Z_OK;
128
78.1k
}
129
130
78.1k
int ZEXPORT inflateReset(z_streamp strm) {
131
78.1k
    struct inflate_state FAR *state;
132
133
78.1k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
134
78.1k
    state = (struct inflate_state FAR *)strm->state;
135
78.1k
    state->wsize = 0;
136
78.1k
    state->whave = 0;
137
78.1k
    state->wnext = 0;
138
78.1k
    return inflateResetKeep(strm);
139
78.1k
}
140
141
78.1k
int ZEXPORT inflateReset2(z_streamp strm, int windowBits) {
142
78.1k
    int wrap;
143
78.1k
    struct inflate_state FAR *state;
144
145
    /* get the state */
146
78.1k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
147
78.1k
    state = (struct inflate_state FAR *)strm->state;
148
149
    /* extract wrap request from windowBits parameter */
150
78.1k
    if (windowBits < 0) {
151
23
        if (windowBits < -15)
152
0
            return Z_STREAM_ERROR;
153
23
        wrap = 0;
154
23
        windowBits = -windowBits;
155
23
    }
156
78.1k
    else {
157
78.1k
        wrap = (windowBits >> 4) + 5;
158
78.1k
#ifdef GUNZIP
159
78.1k
        if (windowBits < 48)
160
78.1k
            windowBits &= 15;
161
78.1k
#endif
162
78.1k
    }
163
164
    /* set number of window bits, free window if different */
165
78.1k
    if (windowBits && (windowBits < 8 || windowBits > 15))
166
0
        return Z_STREAM_ERROR;
167
78.1k
    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
78.1k
    state->wrap = wrap;
174
78.1k
    state->wbits = (unsigned)windowBits;
175
78.1k
    return inflateReset(strm);
176
78.1k
}
177
178
int ZEXPORT inflateInit2_(z_streamp strm, int windowBits,
179
78.1k
                          const char *version, int stream_size) {
180
78.1k
    int ret;
181
78.1k
    struct inflate_state FAR *state;
182
183
78.1k
    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
184
78.1k
        stream_size != (int)(sizeof(z_stream)))
185
0
        return Z_VERSION_ERROR;
186
78.1k
    if (strm == Z_NULL) return Z_STREAM_ERROR;
187
78.1k
    strm->msg = Z_NULL;                 /* in case we return an error */
188
78.1k
    if (strm->zalloc == (alloc_func)0) {
189
#ifdef Z_SOLO
190
        return Z_STREAM_ERROR;
191
#else
192
0
        strm->zalloc = zcalloc;
193
0
        strm->opaque = (voidpf)0;
194
0
#endif
195
0
    }
196
78.1k
    if (strm->zfree == (free_func)0)
197
#ifdef Z_SOLO
198
        return Z_STREAM_ERROR;
199
#else
200
0
        strm->zfree = zcfree;
201
78.1k
#endif
202
78.1k
    state = (struct inflate_state FAR *)
203
78.1k
            ZALLOC(strm, 1, sizeof(struct inflate_state));
204
78.1k
    if (state == Z_NULL) return Z_MEM_ERROR;
205
78.1k
    Tracev((stderr, "inflate: allocated\n"));
206
78.1k
    strm->state = (struct internal_state FAR *)state;
207
78.1k
    state->strm = strm;
208
78.1k
    state->window = Z_NULL;
209
78.1k
    state->mode = HEAD;     /* to pass state test in inflateReset2() */
210
78.1k
    ret = inflateReset2(strm, windowBits);
211
78.1k
    if (ret != Z_OK) {
212
0
        ZFREE(strm, state);
213
0
        strm->state = Z_NULL;
214
0
    }
215
78.1k
    return ret;
216
78.1k
}
217
218
int ZEXPORT inflateInit_(z_streamp strm, const char *version,
219
64
                         int stream_size) {
220
64
    return inflateInit2_(strm, DEF_WBITS, version, stream_size);
221
64
}
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
53.3k
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
53.3k
#   include "inffixed.h"
286
53.3k
#endif /* BUILDFIXED */
287
53.3k
    state->lencode = lenfix;
288
53.3k
    state->lenbits = 9;
289
53.3k
    state->distcode = distfix;
290
53.3k
    state->distbits = 5;
291
53.3k
}
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
3.30M
local int updatewindow(z_streamp strm, const Bytef *end, unsigned copy) {
369
3.30M
    struct inflate_state FAR *state;
370
3.30M
    unsigned dist;
371
372
3.30M
    state = (struct inflate_state FAR *)strm->state;
373
374
    /* if it hasn't been done already, allocate space for the window */
375
3.30M
    if (state->window == Z_NULL) {
376
27.7k
        state->window = (unsigned char FAR *)
377
27.7k
                        ZALLOC(strm, 1U << state->wbits,
378
27.7k
                               sizeof(unsigned char));
379
27.7k
        if (state->window == Z_NULL) return 1;
380
27.7k
    }
381
382
    /* if window not in use yet, initialize */
383
3.30M
    if (state->wsize == 0) {
384
27.7k
        state->wsize = 1U << state->wbits;
385
27.7k
        state->wnext = 0;
386
27.7k
        state->whave = 0;
387
27.7k
    }
388
389
    /* copy state->wsize or less output bytes into the circular window */
390
3.30M
    if (copy >= state->wsize) {
391
2
        zmemcpy(state->window, end - state->wsize, state->wsize);
392
2
        state->wnext = 0;
393
2
        state->whave = state->wsize;
394
2
    }
395
3.30M
    else {
396
3.30M
        dist = state->wsize - state->wnext;
397
3.30M
        if (dist > copy) dist = copy;
398
3.30M
        zmemcpy(state->window + state->wnext, end - copy, dist);
399
3.30M
        copy -= dist;
400
3.30M
        if (copy) {
401
0
            zmemcpy(state->window, end - copy, copy);
402
0
            state->wnext = copy;
403
0
            state->whave = state->wsize;
404
0
        }
405
3.30M
        else {
406
3.30M
            state->wnext += dist;
407
3.30M
            if (state->wnext == state->wsize) state->wnext = 0;
408
3.30M
            if (state->whave < state->wsize) state->whave += dist;
409
3.30M
        }
410
3.30M
    }
411
3.30M
    return 0;
412
3.30M
}
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
2.67M
    (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
88
    do { \
428
88
        hbuf[0] = (unsigned char)(word); \
429
88
        hbuf[1] = (unsigned char)((word) >> 8); \
430
88
        check = crc32(check, hbuf, 2); \
431
88
    } while (0)
432
433
#  define CRC4(check, word) \
434
3
    do { \
435
3
        hbuf[0] = (unsigned char)(word); \
436
3
        hbuf[1] = (unsigned char)((word) >> 8); \
437
3
        hbuf[2] = (unsigned char)((word) >> 16); \
438
3
        hbuf[3] = (unsigned char)((word) >> 24); \
439
3
        check = crc32(check, hbuf, 4); \
440
3
    } while (0)
441
#endif
442
443
/* Load registers with state in inflate() for speed */
444
#define LOAD() \
445
3.91M
    do { \
446
3.91M
        put = strm->next_out; \
447
3.91M
        left = strm->avail_out; \
448
3.91M
        next = strm->next_in; \
449
3.91M
        have = strm->avail_in; \
450
3.91M
        hold = state->hold; \
451
3.91M
        bits = state->bits; \
452
3.91M
    } while (0)
453
454
/* Restore state from registers in inflate() */
455
#define RESTORE() \
456
3.91M
    do { \
457
3.91M
        strm->next_out = put; \
458
3.91M
        strm->avail_out = left; \
459
3.91M
        strm->next_in = next; \
460
3.91M
        strm->avail_in = have; \
461
3.91M
        state->hold = hold; \
462
3.91M
        state->bits = bits; \
463
3.91M
    } while (0)
464
465
/* Clear the input bit accumulator */
466
#define INITBITS() \
467
127k
    do { \
468
127k
        hold = 0; \
469
127k
        bits = 0; \
470
127k
    } 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
18.0M
    do { \
476
18.0M
        if (have == 0) goto inf_leave; \
477
18.0M
        have--; \
478
14.9M
        hold += (unsigned long)(*next++) << bits; \
479
14.9M
        bits += 8; \
480
14.9M
    } 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
5.62M
    do { \
486
9.26M
        while (bits < (unsigned)(n)) \
487
5.62M
            PULLBYTE(); \
488
5.62M
    } while (0)
489
490
/* Return the low n bits of the bit accumulator (n < 16) */
491
#define BITS(n) \
492
39.4M
    ((unsigned)hold & ((1U << (n)) - 1))
493
494
/* Remove n bits from the bit accumulator */
495
#define DROPBITS(n) \
496
25.3M
    do { \
497
25.3M
        hold >>= (n); \
498
25.3M
        bits -= (unsigned)(n); \
499
25.3M
    } while (0)
500
501
/* Remove zero to seven bits as needed to go to a byte boundary */
502
#define BYTEBITS() \
503
59.5k
    do { \
504
59.5k
        hold >>= bits & 7; \
505
59.5k
        bits -= bits & 7; \
506
59.5k
    } 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
3.47M
int ZEXPORT inflate(z_streamp strm, int flush) {
591
3.47M
    struct inflate_state FAR *state;
592
3.47M
    z_const unsigned char FAR *next;    /* next input */
593
3.47M
    unsigned char FAR *put;     /* next output */
594
3.47M
    unsigned have, left;        /* available input and output */
595
3.47M
    unsigned long hold;         /* bit buffer */
596
3.47M
    unsigned bits;              /* bits in bit buffer */
597
3.47M
    unsigned in, out;           /* save starting available input and output */
598
3.47M
    unsigned copy;              /* number of stored or match bytes to copy */
599
3.47M
    unsigned char FAR *from;    /* where to copy match bytes from */
600
3.47M
    code here;                  /* current decoding table entry */
601
3.47M
    code last;                  /* parent table entry */
602
3.47M
    unsigned len;               /* length to copy for repeats, bits to drop */
603
3.47M
    int ret;                    /* return code */
604
3.47M
#ifdef GUNZIP
605
3.47M
    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
606
3.47M
#endif
607
3.47M
    static const unsigned short order[19] = /* permutation of code lengths */
608
3.47M
        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
609
610
3.47M
    if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
611
3.47M
        (strm->next_in == Z_NULL && strm->avail_in != 0))
612
0
        return Z_STREAM_ERROR;
613
614
3.47M
    state = (struct inflate_state FAR *)strm->state;
615
3.47M
    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
616
3.47M
    LOAD();
617
3.47M
    in = have;
618
3.47M
    out = left;
619
3.47M
    ret = Z_OK;
620
3.47M
    for (;;)
621
19.5M
        switch (state->mode) {
622
79.3k
        case HEAD:
623
79.3k
            if (state->wrap == 0) {
624
23
                state->mode = TYPEDO;
625
23
                break;
626
23
            }
627
79.2k
            NEEDBITS(16);
628
77.7k
#ifdef GUNZIP
629
77.7k
            if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
630
80
                if (state->wbits == 0)
631
0
                    state->wbits = 15;
632
80
                state->check = crc32(0L, Z_NULL, 0);
633
80
                CRC2(state->check, hold);
634
80
                INITBITS();
635
80
                state->mode = FLAGS;
636
80
                break;
637
80
            }
638
77.6k
            if (state->head != Z_NULL)
639
0
                state->head->done = -1;
640
77.6k
            if (!(state->wrap & 1) ||   /* check if zlib header allowed */
641
#else
642
            if (
643
#endif
644
77.6k
                ((BITS(8) << 8) + (hold >> 8)) % 31) {
645
270
                strm->msg = (char *)"incorrect header check";
646
270
                state->mode = BAD;
647
270
                break;
648
270
            }
649
77.3k
            if (BITS(4) != Z_DEFLATED) {
650
136
                strm->msg = (char *)"unknown compression method";
651
136
                state->mode = BAD;
652
136
                break;
653
136
            }
654
77.2k
            DROPBITS(4);
655
77.2k
            len = BITS(4) + 8;
656
77.2k
            if (state->wbits == 0)
657
0
                state->wbits = len;
658
77.2k
            if (len > 15 || len > state->wbits) {
659
0
                strm->msg = (char *)"invalid window size";
660
0
                state->mode = BAD;
661
0
                break;
662
0
            }
663
77.2k
            state->dmax = 1U << len;
664
77.2k
            state->flags = 0;               /* indicate zlib header */
665
77.2k
            Tracev((stderr, "inflate:   zlib header ok\n"));
666
77.2k
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
667
77.2k
            state->mode = hold & 0x200 ? DICTID : TYPE;
668
77.2k
            INITBITS();
669
77.2k
            break;
670
0
#ifdef GUNZIP
671
80
        case FLAGS:
672
80
            NEEDBITS(16);
673
80
            state->flags = (int)(hold);
674
80
            if ((state->flags & 0xff) != Z_DEFLATED) {
675
0
                strm->msg = (char *)"unknown compression method";
676
0
                state->mode = BAD;
677
0
                break;
678
0
            }
679
80
            if (state->flags & 0xe000) {
680
0
                strm->msg = (char *)"unknown header flags set";
681
0
                state->mode = BAD;
682
0
                break;
683
0
            }
684
80
            if (state->head != Z_NULL)
685
0
                state->head->text = (int)((hold >> 8) & 1);
686
80
            if ((state->flags & 0x0200) && (state->wrap & 4))
687
3
                CRC2(state->check, hold);
688
80
            INITBITS();
689
80
            state->mode = TIME;
690
                /* fallthrough */
691
80
        case TIME:
692
80
            NEEDBITS(32);
693
80
            if (state->head != Z_NULL)
694
0
                state->head->time = hold;
695
80
            if ((state->flags & 0x0200) && (state->wrap & 4))
696
3
                CRC4(state->check, hold);
697
80
            INITBITS();
698
80
            state->mode = OS;
699
                /* fallthrough */
700
80
        case OS:
701
80
            NEEDBITS(16);
702
80
            if (state->head != Z_NULL) {
703
0
                state->head->xflags = (int)(hold & 0xff);
704
0
                state->head->os = (int)(hold >> 8);
705
0
            }
706
80
            if ((state->flags & 0x0200) && (state->wrap & 4))
707
3
                CRC2(state->check, hold);
708
80
            INITBITS();
709
80
            state->mode = EXLEN;
710
                /* fallthrough */
711
80
        case EXLEN:
712
80
            if (state->flags & 0x0400) {
713
2
                NEEDBITS(16);
714
2
                state->length = (unsigned)(hold);
715
2
                if (state->head != Z_NULL)
716
0
                    state->head->extra_len = (unsigned)hold;
717
2
                if ((state->flags & 0x0200) && (state->wrap & 4))
718
2
                    CRC2(state->check, hold);
719
2
                INITBITS();
720
2
            }
721
78
            else if (state->head != Z_NULL)
722
0
                state->head->extra = Z_NULL;
723
80
            state->mode = EXTRA;
724
                /* fallthrough */
725
80
        case EXTRA:
726
80
            if (state->flags & 0x0400) {
727
2
                copy = state->length;
728
2
                if (copy > have) copy = have;
729
2
                if (copy) {
730
2
                    if (state->head != Z_NULL &&
731
2
                        state->head->extra != Z_NULL &&
732
2
                        (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
2
                    if ((state->flags & 0x0200) && (state->wrap & 4))
739
2
                        state->check = crc32(state->check, next, copy);
740
2
                    have -= copy;
741
2
                    next += copy;
742
2
                    state->length -= copy;
743
2
                }
744
2
                if (state->length) goto inf_leave;
745
2
            }
746
80
            state->length = 0;
747
80
            state->mode = NAME;
748
                /* fallthrough */
749
81
        case NAME:
750
81
            if (state->flags & 0x0800) {
751
5
                if (have == 0) goto inf_leave;
752
4
                copy = 0;
753
435
                do {
754
435
                    len = (unsigned)(next[copy++]);
755
435
                    if (state->head != Z_NULL &&
756
435
                            state->head->name != Z_NULL &&
757
435
                            state->length < state->head->name_max)
758
0
                        state->head->name[state->length++] = (Bytef)len;
759
435
                } while (len && copy < have);
760
4
                if ((state->flags & 0x0200) && (state->wrap & 4))
761
3
                    state->check = crc32(state->check, next, copy);
762
4
                have -= copy;
763
4
                next += copy;
764
4
                if (len) goto inf_leave;
765
4
            }
766
76
            else if (state->head != Z_NULL)
767
0
                state->head->name = Z_NULL;
768
79
            state->length = 0;
769
79
            state->mode = COMMENT;
770
                /* fallthrough */
771
81
        case COMMENT:
772
81
            if (state->flags & 0x1000) {
773
4
                if (have == 0) goto inf_leave;
774
2
                copy = 0;
775
114
                do {
776
114
                    len = (unsigned)(next[copy++]);
777
114
                    if (state->head != Z_NULL &&
778
114
                            state->head->comment != Z_NULL &&
779
114
                            state->length < state->head->comm_max)
780
0
                        state->head->comment[state->length++] = (Bytef)len;
781
114
                } while (len && copy < have);
782
2
                if ((state->flags & 0x0200) && (state->wrap & 4))
783
2
                    state->check = crc32(state->check, next, copy);
784
2
                have -= copy;
785
2
                next += copy;
786
2
                if (len) goto inf_leave;
787
2
            }
788
77
            else if (state->head != Z_NULL)
789
0
                state->head->comment = Z_NULL;
790
77
            state->mode = HCRC;
791
                /* fallthrough */
792
77
        case HCRC:
793
77
            if (state->flags & 0x0200) {
794
0
                NEEDBITS(16);
795
0
                if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
796
0
                    strm->msg = (char *)"header crc mismatch";
797
0
                    state->mode = BAD;
798
0
                    break;
799
0
                }
800
0
                INITBITS();
801
0
            }
802
77
            if (state->head != Z_NULL) {
803
0
                state->head->hcrc = (int)((state->flags >> 9) & 1);
804
0
                state->head->done = 1;
805
0
            }
806
77
            strm->adler = state->check = crc32(0L, Z_NULL, 0);
807
77
            state->mode = TYPE;
808
77
            break;
809
0
#endif
810
6
        case DICTID:
811
6
            NEEDBITS(32);
812
2
            strm->adler = state->check = ZSWAP32(hold);
813
2
            INITBITS();
814
2
            state->mode = DICT;
815
                /* fallthrough */
816
2
        case DICT:
817
2
            if (state->havedict == 0) {
818
2
                RESTORE();
819
2
                return Z_NEED_DICT;
820
2
            }
821
0
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
822
0
            state->mode = TYPE;
823
                /* fallthrough */
824
180k
        case TYPE:
825
180k
            if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
826
                /* fallthrough */
827
182k
        case TYPEDO:
828
182k
            if (state->last) {
829
58.3k
                BYTEBITS();
830
58.3k
                state->mode = CHECK;
831
58.3k
                break;
832
58.3k
            }
833
124k
            NEEDBITS(3);
834
122k
            state->last = BITS(1);
835
122k
            DROPBITS(1);
836
122k
            switch (BITS(2)) {
837
1.12k
            case 0:                             /* stored block */
838
1.12k
                Tracev((stderr, "inflate:     stored block%s\n",
839
1.12k
                        state->last ? " (last)" : ""));
840
1.12k
                state->mode = STORED;
841
1.12k
                break;
842
53.3k
            case 1:                             /* fixed block */
843
53.3k
                fixedtables(state);
844
53.3k
                Tracev((stderr, "inflate:     fixed codes block%s\n",
845
53.3k
                        state->last ? " (last)" : ""));
846
53.3k
                state->mode = LEN_;             /* decode codes */
847
53.3k
                if (flush == Z_TREES) {
848
0
                    DROPBITS(2);
849
0
                    goto inf_leave;
850
0
                }
851
53.3k
                break;
852
67.9k
            case 2:                             /* dynamic block */
853
67.9k
                Tracev((stderr, "inflate:     dynamic codes block%s\n",
854
67.9k
                        state->last ? " (last)" : ""));
855
67.9k
                state->mode = TABLE;
856
67.9k
                break;
857
133
            case 3:
858
133
                strm->msg = (char *)"invalid block type";
859
133
                state->mode = BAD;
860
122k
            }
861
122k
            DROPBITS(2);
862
122k
            break;
863
1.24k
        case STORED:
864
1.24k
            BYTEBITS();                         /* go to byte boundary */
865
1.24k
            NEEDBITS(32);
866
1.11k
            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
867
211
                strm->msg = (char *)"invalid stored block lengths";
868
211
                state->mode = BAD;
869
211
                break;
870
211
            }
871
902
            state->length = (unsigned)hold & 0xffff;
872
902
            Tracev((stderr, "inflate:       stored length %u\n",
873
902
                    state->length));
874
902
            INITBITS();
875
902
            state->mode = COPY_;
876
902
            if (flush == Z_TREES) goto inf_leave;
877
                /* fallthrough */
878
902
        case COPY_:
879
902
            state->mode = COPY;
880
                /* fallthrough */
881
2.28k
        case COPY:
882
2.28k
            copy = state->length;
883
2.28k
            if (copy) {
884
1.39k
                if (copy > have) copy = have;
885
1.39k
                if (copy > left) copy = left;
886
1.39k
                if (copy == 0) goto inf_leave;
887
1.00k
                zmemcpy(put, next, copy);
888
1.00k
                have -= copy;
889
1.00k
                next += copy;
890
1.00k
                left -= copy;
891
1.00k
                put += copy;
892
1.00k
                state->length -= copy;
893
1.00k
                break;
894
1.39k
            }
895
889
            Tracev((stderr, "inflate:       stored end\n"));
896
889
            state->mode = TYPE;
897
889
            break;
898
71.3k
        case TABLE:
899
71.3k
            NEEDBITS(14);
900
67.9k
            state->nlen = BITS(5) + 257;
901
67.9k
            DROPBITS(5);
902
67.9k
            state->ndist = BITS(5) + 1;
903
67.9k
            DROPBITS(5);
904
67.9k
            state->ncode = BITS(4) + 4;
905
67.9k
            DROPBITS(4);
906
67.9k
#ifndef PKZIP_BUG_WORKAROUND
907
67.9k
            if (state->nlen > 286 || state->ndist > 30) {
908
9
                strm->msg = (char *)"too many length or distance symbols";
909
9
                state->mode = BAD;
910
9
                break;
911
9
            }
912
67.9k
#endif
913
67.9k
            Tracev((stderr, "inflate:       table sizes ok\n"));
914
67.9k
            state->have = 0;
915
67.9k
            state->mode = LENLENS;
916
                /* fallthrough */
917
77.2k
        case LENLENS:
918
1.11M
            while (state->have < state->ncode) {
919
1.04M
                NEEDBITS(3);
920
1.03M
                state->lens[order[state->have++]] = (unsigned short)BITS(3);
921
1.03M
                DROPBITS(3);
922
1.03M
            }
923
324k
            while (state->have < 19)
924
256k
                state->lens[order[state->have++]] = 0;
925
67.9k
            state->next = state->codes;
926
67.9k
            state->lencode = (const code FAR *)(state->next);
927
67.9k
            state->lenbits = 7;
928
67.9k
            ret = inflate_table(CODES, state->lens, 19, &(state->next),
929
67.9k
                                &(state->lenbits), state->work);
930
67.9k
            if (ret) {
931
431
                strm->msg = (char *)"invalid code lengths set";
932
431
                state->mode = BAD;
933
431
                break;
934
431
            }
935
67.5k
            Tracev((stderr, "inflate:       code lengths ok\n"));
936
67.5k
            state->have = 0;
937
67.5k
            state->mode = CODELENS;
938
                /* fallthrough */
939
195k
        case CODELENS:
940
8.20M
            while (state->have < state->nlen + state->ndist) {
941
11.2M
                for (;;) {
942
11.2M
                    here = state->lencode[BITS(state->lenbits)];
943
11.2M
                    if ((unsigned)(here.bits) <= bits) break;
944
3.21M
                    PULLBYTE();
945
3.21M
                }
946
8.02M
                if (here.val < 16) {
947
7.20M
                    DROPBITS(here.bits);
948
7.20M
                    state->lens[state->have++] = here.val;
949
7.20M
                }
950
818k
                else {
951
818k
                    if (here.val == 16) {
952
351k
                        NEEDBITS(here.bits + 2);
953
349k
                        DROPBITS(here.bits);
954
349k
                        if (state->have == 0) {
955
3
                            strm->msg = (char *)"invalid bit length repeat";
956
3
                            state->mode = BAD;
957
3
                            break;
958
3
                        }
959
349k
                        len = state->lens[state->have - 1];
960
349k
                        copy = 3 + BITS(2);
961
349k
                        DROPBITS(2);
962
349k
                    }
963
466k
                    else if (here.val == 17) {
964
289k
                        NEEDBITS(here.bits + 3);
965
286k
                        DROPBITS(here.bits);
966
286k
                        len = 0;
967
286k
                        copy = 3 + BITS(3);
968
286k
                        DROPBITS(3);
969
286k
                    }
970
177k
                    else {
971
177k
                        NEEDBITS(here.bits + 7);
972
173k
                        DROPBITS(here.bits);
973
173k
                        len = 0;
974
173k
                        copy = 11 + BITS(7);
975
173k
                        DROPBITS(7);
976
173k
                    }
977
810k
                    if (state->have + copy > state->nlen + state->ndist) {
978
122
                        strm->msg = (char *)"invalid bit length repeat";
979
122
                        state->mode = BAD;
980
122
                        break;
981
122
                    }
982
13.6M
                    while (copy--)
983
12.8M
                        state->lens[state->have++] = (unsigned short)len;
984
809k
                }
985
8.02M
            }
986
987
            /* handle error breaks in while */
988
67.4k
            if (state->mode == BAD) break;
989
990
            /* check for end-of-block code (better have one) */
991
67.3k
            if (state->lens[256] == 0) {
992
37
                strm->msg = (char *)"invalid code -- missing end-of-block";
993
37
                state->mode = BAD;
994
37
                break;
995
37
            }
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
67.3k
            state->next = state->codes;
1001
67.3k
            state->lencode = (const code FAR *)(state->next);
1002
67.3k
            state->lenbits = 9;
1003
67.3k
            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1004
67.3k
                                &(state->lenbits), state->work);
1005
67.3k
            if (ret) {
1006
711
                strm->msg = (char *)"invalid literal/lengths set";
1007
711
                state->mode = BAD;
1008
711
                break;
1009
711
            }
1010
66.5k
            state->distcode = (const code FAR *)(state->next);
1011
66.5k
            state->distbits = 6;
1012
66.5k
            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1013
66.5k
                            &(state->next), &(state->distbits), state->work);
1014
66.5k
            if (ret) {
1015
785
                strm->msg = (char *)"invalid distances set";
1016
785
                state->mode = BAD;
1017
785
                break;
1018
785
            }
1019
65.8k
            Tracev((stderr, "inflate:       codes ok\n"));
1020
65.8k
            state->mode = LEN_;
1021
65.8k
            if (flush == Z_TREES) goto inf_leave;
1022
                /* fallthrough */
1023
119k
        case LEN_:
1024
119k
            state->mode = LEN;
1025
                /* fallthrough */
1026
11.4M
        case LEN:
1027
11.4M
            if (have >= 6 && left >= 258) {
1028
441k
                RESTORE();
1029
441k
                inflate_fast(strm, out);
1030
441k
                LOAD();
1031
441k
                if (state->mode == TYPE)
1032
52.9k
                    state->back = -1;
1033
441k
                break;
1034
441k
            }
1035
11.0M
            state->back = 0;
1036
17.6M
            for (;;) {
1037
17.6M
                here = state->lencode[BITS(state->lenbits)];
1038
17.6M
                if ((unsigned)(here.bits) <= bits) break;
1039
8.75M
                PULLBYTE();
1040
8.75M
            }
1041
8.92M
            if (here.op && (here.op & 0xf0) == 0) {
1042
381k
                last = here;
1043
441k
                for (;;) {
1044
441k
                    here = state->lencode[last.val +
1045
441k
                            (BITS(last.bits + last.op) >> last.bits)];
1046
441k
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1047
79.4k
                    PULLBYTE();
1048
79.4k
                }
1049
361k
                DROPBITS(last.bits);
1050
361k
                state->back += last.bits;
1051
361k
            }
1052
8.90M
            DROPBITS(here.bits);
1053
8.90M
            state->back += here.bits;
1054
8.90M
            state->length = (unsigned)here.val;
1055
8.90M
            if ((int)(here.op) == 0) {
1056
6.09M
                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1057
6.09M
                        "inflate:         literal '%c'\n" :
1058
6.09M
                        "inflate:         literal 0x%02x\n", here.val));
1059
6.09M
                state->mode = LIT;
1060
6.09M
                break;
1061
6.09M
            }
1062
2.81M
            if (here.op & 32) {
1063
49.6k
                Tracevv((stderr, "inflate:         end of block\n"));
1064
49.6k
                state->back = -1;
1065
49.6k
                state->mode = TYPE;
1066
49.6k
                break;
1067
49.6k
            }
1068
2.76M
            if (here.op & 64) {
1069
42
                strm->msg = (char *)"invalid literal/length code";
1070
42
                state->mode = BAD;
1071
42
                break;
1072
42
            }
1073
2.76M
            state->extra = (unsigned)(here.op) & 15;
1074
2.76M
            state->mode = LENEXT;
1075
                /* fallthrough */
1076
2.77M
        case LENEXT:
1077
2.77M
            if (state->extra) {
1078
422k
                NEEDBITS(state->extra);
1079
406k
                state->length += BITS(state->extra);
1080
406k
                DROPBITS(state->extra);
1081
406k
                state->back += state->extra;
1082
406k
            }
1083
2.76M
            Tracevv((stderr, "inflate:         length %u\n", state->length));
1084
2.76M
            state->was = state->length;
1085
2.76M
            state->mode = DIST;
1086
                /* fallthrough */
1087
3.09M
        case DIST:
1088
4.58M
            for (;;) {
1089
4.58M
                here = state->distcode[BITS(state->distbits)];
1090
4.58M
                if ((unsigned)(here.bits) <= bits) break;
1091
1.81M
                PULLBYTE();
1092
1.81M
            }
1093
2.76M
            if ((here.op & 0xf0) == 0) {
1094
50.0k
                last = here;
1095
59.0k
                for (;;) {
1096
59.0k
                    here = state->distcode[last.val +
1097
59.0k
                            (BITS(last.bits + last.op) >> last.bits)];
1098
59.0k
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1099
11.0k
                    PULLBYTE();
1100
11.0k
                }
1101
47.9k
                DROPBITS(last.bits);
1102
47.9k
                state->back += last.bits;
1103
47.9k
            }
1104
2.76M
            DROPBITS(here.bits);
1105
2.76M
            state->back += here.bits;
1106
2.76M
            if (here.op & 64) {
1107
23
                strm->msg = (char *)"invalid distance code";
1108
23
                state->mode = BAD;
1109
23
                break;
1110
23
            }
1111
2.76M
            state->offset = (unsigned)here.val;
1112
2.76M
            state->extra = (unsigned)(here.op) & 15;
1113
2.76M
            state->mode = DISTEXT;
1114
                /* fallthrough */
1115
3.24M
        case DISTEXT:
1116
3.24M
            if (state->extra) {
1117
2.99M
                NEEDBITS(state->extra);
1118
2.51M
                state->offset += BITS(state->extra);
1119
2.51M
                DROPBITS(state->extra);
1120
2.51M
                state->back += state->extra;
1121
2.51M
            }
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
2.76M
            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
1130
2.76M
            state->mode = MATCH;
1131
                /* fallthrough */
1132
3.38M
        case MATCH:
1133
3.38M
            if (left == 0) goto inf_leave;
1134
3.14M
            copy = out - left;
1135
3.14M
            if (state->offset > copy) {         /* copy from window */
1136
1.21M
                copy = state->offset - copy;
1137
1.21M
                if (copy > state->whave) {
1138
946
                    if (state->sane) {
1139
946
                        strm->msg = (char *)"invalid distance too far back";
1140
946
                        state->mode = BAD;
1141
946
                        break;
1142
946
                    }
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
946
                }
1157
1.21M
                if (copy > state->wnext) {
1158
76.3k
                    copy -= state->wnext;
1159
76.3k
                    from = state->window + (state->wsize - copy);
1160
76.3k
                }
1161
1.13M
                else
1162
1.13M
                    from = state->window + (state->wnext - copy);
1163
1.21M
                if (copy > state->length) copy = state->length;
1164
1.21M
            }
1165
1.93M
            else {                              /* copy from output */
1166
1.93M
                from = put - state->offset;
1167
1.93M
                copy = state->length;
1168
1.93M
            }
1169
3.14M
            if (copy > left) copy = left;
1170
3.14M
            left -= copy;
1171
3.14M
            state->length -= copy;
1172
66.4M
            do {
1173
66.4M
                *put++ = *from++;
1174
66.4M
            } while (--copy);
1175
3.14M
            if (state->length == 0) state->mode = LEN;
1176
3.14M
            break;
1177
6.10M
        case LIT:
1178
6.10M
            if (left == 0) goto inf_leave;
1179
6.09M
            *put++ = (unsigned char)(state->length);
1180
6.09M
            left--;
1181
6.09M
            state->mode = LEN;
1182
6.09M
            break;
1183
61.2k
        case CHECK:
1184
61.2k
            if (state->wrap) {
1185
61.2k
                NEEDBITS(32);
1186
58.2k
                out -= left;
1187
58.2k
                strm->total_out += out;
1188
58.2k
                state->total += out;
1189
58.2k
                if ((state->wrap & 4) && out)
1190
55.4k
                    strm->adler = state->check =
1191
55.4k
                        UPDATE_CHECK(state->check, put - out, out);
1192
58.2k
                out = left;
1193
58.2k
                if ((state->wrap & 4) && (
1194
58.2k
#ifdef GUNZIP
1195
58.2k
                     state->flags ? hold :
1196
58.2k
#endif
1197
58.2k
                     ZSWAP32(hold)) != state->check) {
1198
9.10k
                    strm->msg = (char *)"incorrect data check";
1199
9.10k
                    state->mode = BAD;
1200
9.10k
                    break;
1201
9.10k
                }
1202
49.1k
                INITBITS();
1203
49.1k
                Tracev((stderr, "inflate:   check matches trailer\n"));
1204
49.1k
            }
1205
49.1k
#ifdef GUNZIP
1206
49.1k
            state->mode = LENGTH;
1207
                /* fallthrough */
1208
49.1k
        case LENGTH:
1209
49.1k
            if (state->wrap && state->flags) {
1210
0
                NEEDBITS(32);
1211
0
                if ((state->wrap & 4) && hold != (state->total & 0xffffffff)) {
1212
0
                    strm->msg = (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
49.1k
#endif
1220
49.1k
            state->mode = DONE;
1221
                /* fallthrough */
1222
82.9k
        case DONE:
1223
82.9k
            ret = Z_STREAM_END;
1224
82.9k
            goto inf_leave;
1225
20.1k
        case BAD:
1226
20.1k
            ret = Z_DATA_ERROR;
1227
20.1k
            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
19.5M
        }
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
3.47M
  inf_leave:
1243
3.47M
    RESTORE();
1244
3.47M
    if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
1245
201k
            (state->mode < CHECK || flush != Z_FINISH)))
1246
3.30M
        if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
1247
0
            state->mode = MEM;
1248
0
            return Z_MEM_ERROR;
1249
0
        }
1250
3.47M
    in -= strm->avail_in;
1251
3.47M
    out -= strm->avail_out;
1252
3.47M
    strm->total_in += in;
1253
3.47M
    strm->total_out += out;
1254
3.47M
    state->total += out;
1255
3.47M
    if ((state->wrap & 4) && out)
1256
2.61M
        strm->adler = state->check =
1257
2.61M
            UPDATE_CHECK(state->check, strm->next_out - out, out);
1258
3.47M
    strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
1259
3.47M
                      (state->mode == TYPE ? 128 : 0) +
1260
3.47M
                      (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1261
3.47M
    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1262
7.40k
        ret = Z_BUF_ERROR;
1263
3.47M
    return ret;
1264
3.47M
}
1265
1266
78.1k
int ZEXPORT inflateEnd(z_streamp strm) {
1267
78.1k
    struct inflate_state FAR *state;
1268
78.1k
    if (inflateStateCheck(strm))
1269
0
        return Z_STREAM_ERROR;
1270
78.1k
    state = (struct inflate_state FAR *)strm->state;
1271
78.1k
    if (state->window != Z_NULL) ZFREE(strm, state->window);
1272
78.1k
    ZFREE(strm, strm->state);
1273
78.1k
    strm->state = Z_NULL;
1274
78.1k
    Tracev((stderr, "inflate: end\n"));
1275
78.1k
    return Z_OK;
1276
78.1k
}
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
}