Coverage Report

Created: 2024-06-18 06:05

/src/zlib/inflate.c
Line
Count
Source (jump to first uncovered line)
1
/* inflate.c -- zlib decompression
2
 * Copyright (C) 1995-2022 Mark Adler
3
 * For conditions of distribution and use, see copyright notice in zlib.h
4
 */
5
6
/*
7
 * Change history:
8
 *
9
 * 1.2.beta0    24 Nov 2002
10
 * - First version -- complete rewrite of inflate to simplify code, avoid
11
 *   creation of window when not needed, minimize use of window when it is
12
 *   needed, make inffast.c even faster, implement gzip decoding, and to
13
 *   improve code readability and style over the previous zlib inflate code
14
 *
15
 * 1.2.beta1    25 Nov 2002
16
 * - Use pointers for available input and output checking in inffast.c
17
 * - Remove input and output counters in inffast.c
18
 * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
19
 * - Remove unnecessary second byte pull from length extra in inffast.c
20
 * - Unroll direct copy to three copies per loop in inffast.c
21
 *
22
 * 1.2.beta2    4 Dec 2002
23
 * - Change external routine names to reduce potential conflicts
24
 * - Correct filename to inffixed.h for fixed tables in inflate.c
25
 * - Make hbuf[] unsigned char to match parameter type in inflate.c
26
 * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
27
 *   to avoid negation problem on Alphas (64 bit) in inflate.c
28
 *
29
 * 1.2.beta3    22 Dec 2002
30
 * - Add comments on state->bits assertion in inffast.c
31
 * - Add comments on op field in inftrees.h
32
 * - Fix bug in reuse of allocated window after inflateReset()
33
 * - Remove bit fields--back to byte structure for speed
34
 * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
35
 * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
36
 * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
37
 * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
38
 * - Use local copies of stream next and avail values, as well as local bit
39
 *   buffer and bit count in inflate()--for speed when inflate_fast() not used
40
 *
41
 * 1.2.beta4    1 Jan 2003
42
 * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
43
 * - Move a comment on output buffer sizes from inffast.c to inflate.c
44
 * - Add comments in inffast.c to introduce the inflate_fast() routine
45
 * - Rearrange window copies in inflate_fast() for speed and simplification
46
 * - Unroll last copy for window match in inflate_fast()
47
 * - Use local copies of window variables in inflate_fast() for speed
48
 * - Pull out common wnext == 0 case for speed in inflate_fast()
49
 * - Make op and len in inflate_fast() unsigned for consistency
50
 * - Add FAR to lcode and dcode declarations in inflate_fast()
51
 * - Simplified bad distance check in inflate_fast()
52
 * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
53
 *   source file infback.c to provide a call-back interface to inflate for
54
 *   programs like gzip and unzip -- uses window as output buffer to avoid
55
 *   window copying
56
 *
57
 * 1.2.beta5    1 Jan 2003
58
 * - Improved inflateBack() interface to allow the caller to provide initial
59
 *   input in strm.
60
 * - Fixed stored blocks bug in inflateBack()
61
 *
62
 * 1.2.beta6    4 Jan 2003
63
 * - Added comments in inffast.c on effectiveness of POSTINC
64
 * - Typecasting all around to reduce compiler warnings
65
 * - Changed loops from while (1) or do {} while (1) to for (;;), again to
66
 *   make compilers happy
67
 * - Changed type of window in inflateBackInit() to unsigned char *
68
 *
69
 * 1.2.beta7    27 Jan 2003
70
 * - Changed many types to unsigned or unsigned short to avoid warnings
71
 * - Added inflateCopy() function
72
 *
73
 * 1.2.0        9 Mar 2003
74
 * - Changed inflateBack() interface to provide separate opaque descriptors
75
 *   for the in() and out() functions
76
 * - Changed inflateBack() argument and in_func typedef to swap the length
77
 *   and buffer address return values for the input function
78
 * - Check next_in and next_out for Z_NULL on entry to inflate()
79
 *
80
 * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
81
 */
82
83
#include "zutil.h"
84
#include "inftrees.h"
85
#include "inflate.h"
86
#include "inffast.h"
87
88
#ifdef MAKEFIXED
89
#  ifndef BUILDFIXED
90
#    define BUILDFIXED
91
#  endif
92
#endif
93
94
49.3k
local int inflateStateCheck(z_streamp strm) {
95
49.3k
    struct inflate_state FAR *state;
96
49.3k
    if (strm == Z_NULL ||
97
49.3k
        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
98
0
        return 1;
99
49.3k
    state = (struct inflate_state FAR *)strm->state;
100
49.3k
    if (state == Z_NULL || state->strm != strm ||
101
49.3k
        state->mode < HEAD || state->mode > SYNC)
102
5
        return 1;
103
49.3k
    return 0;
104
49.3k
}
105
106
1.66k
int ZEXPORT inflateResetKeep(z_streamp strm) {
107
1.66k
    struct inflate_state FAR *state;
108
109
1.66k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
110
1.66k
    state = (struct inflate_state FAR *)strm->state;
111
1.66k
    strm->total_in = strm->total_out = state->total = 0;
112
1.66k
    strm->msg = Z_NULL;
113
1.66k
    if (state->wrap)        /* to support ill-conceived Java test suite */
114
1.66k
        strm->adler = state->wrap & 1;
115
1.66k
    state->mode = HEAD;
116
1.66k
    state->last = 0;
117
1.66k
    state->havedict = 0;
118
1.66k
    state->flags = -1;
119
1.66k
    state->dmax = 32768U;
120
1.66k
    state->head = Z_NULL;
121
1.66k
    state->hold = 0;
122
1.66k
    state->bits = 0;
123
1.66k
    state->lencode = state->distcode = state->next = state->codes;
124
1.66k
    state->sane = 1;
125
1.66k
    state->back = -1;
126
1.66k
    Tracev((stderr, "inflate: reset\n"));
127
1.66k
    return Z_OK;
128
1.66k
}
129
130
1.66k
int ZEXPORT inflateReset(z_streamp strm) {
131
1.66k
    struct inflate_state FAR *state;
132
133
1.66k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
134
1.66k
    state = (struct inflate_state FAR *)strm->state;
135
1.66k
    state->wsize = 0;
136
1.66k
    state->whave = 0;
137
1.66k
    state->wnext = 0;
138
1.66k
    return inflateResetKeep(strm);
139
1.66k
}
140
141
1.66k
int ZEXPORT inflateReset2(z_streamp strm, int windowBits) {
142
1.66k
    int wrap;
143
1.66k
    struct inflate_state FAR *state;
144
145
    /* get the state */
146
1.66k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
147
1.66k
    state = (struct inflate_state FAR *)strm->state;
148
149
    /* extract wrap request from windowBits parameter */
150
1.66k
    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
1.66k
    else {
157
1.66k
        wrap = (windowBits >> 4) + 5;
158
1.66k
#ifdef GUNZIP
159
1.66k
        if (windowBits < 48)
160
1.66k
            windowBits &= 15;
161
1.66k
#endif
162
1.66k
    }
163
164
    /* set number of window bits, free window if different */
165
1.66k
    if (windowBits && (windowBits < 8 || windowBits > 15))
166
0
        return Z_STREAM_ERROR;
167
1.66k
    if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
168
1.56k
        ZFREE(strm, state->window);
169
1.56k
        state->window = Z_NULL;
170
1.56k
    }
171
172
    /* update state and reset the rest of it */
173
1.66k
    state->wrap = wrap;
174
1.66k
    state->wbits = (unsigned)windowBits;
175
1.66k
    return inflateReset(strm);
176
1.66k
}
177
178
int ZEXPORT inflateInit2_(z_streamp strm, int windowBits,
179
103
                          const char *version, int stream_size) {
180
103
    int ret;
181
103
    struct inflate_state FAR *state;
182
183
103
    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
184
103
        stream_size != (int)(sizeof(z_stream)))
185
0
        return Z_VERSION_ERROR;
186
103
    if (strm == Z_NULL) return Z_STREAM_ERROR;
187
103
    strm->msg = Z_NULL;                 /* in case we return an error */
188
103
    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
103
    if (strm->zfree == (free_func)0)
197
#ifdef Z_SOLO
198
        return Z_STREAM_ERROR;
199
#else
200
0
        strm->zfree = zcfree;
201
103
#endif
202
103
    state = (struct inflate_state FAR *)
203
103
            ZALLOC(strm, 1, sizeof(struct inflate_state));
204
103
    if (state == Z_NULL) return Z_MEM_ERROR;
205
103
    Tracev((stderr, "inflate: allocated\n"));
206
103
    strm->state = (struct internal_state FAR *)state;
207
103
    state->strm = strm;
208
103
    state->window = Z_NULL;
209
103
    state->mode = HEAD;     /* to pass state test in inflateReset2() */
210
103
    ret = inflateReset2(strm, windowBits);
211
103
    if (ret != Z_OK) {
212
0
        ZFREE(strm, state);
213
0
        strm->state = Z_NULL;
214
0
    }
215
103
    return ret;
216
103
}
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
10.8k
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
10.8k
#   include "inffixed.h"
286
10.8k
#endif /* BUILDFIXED */
287
10.8k
    state->lencode = lenfix;
288
10.8k
    state->lenbits = 9;
289
10.8k
    state->distcode = distfix;
290
10.8k
    state->distbits = 5;
291
10.8k
}
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
44.2k
local int updatewindow(z_streamp strm, const Bytef *end, unsigned copy) {
369
44.2k
    struct inflate_state FAR *state;
370
44.2k
    unsigned dist;
371
372
44.2k
    state = (struct inflate_state FAR *)strm->state;
373
374
    /* if it hasn't been done already, allocate space for the window */
375
44.2k
    if (state->window == Z_NULL) {
376
1.66k
        state->window = (unsigned char FAR *)
377
1.66k
                        ZALLOC(strm, 1U << state->wbits,
378
1.66k
                               sizeof(unsigned char));
379
1.66k
        if (state->window == Z_NULL) return 1;
380
1.66k
    }
381
382
    /* if window not in use yet, initialize */
383
44.2k
    if (state->wsize == 0) {
384
1.66k
        state->wsize = 1U << state->wbits;
385
1.66k
        state->wnext = 0;
386
1.66k
        state->whave = 0;
387
1.66k
    }
388
389
    /* copy state->wsize or less output bytes into the circular window */
390
44.2k
    if (copy >= state->wsize) {
391
356
        zmemcpy(state->window, end - state->wsize, state->wsize);
392
356
        state->wnext = 0;
393
356
        state->whave = state->wsize;
394
356
    }
395
43.8k
    else {
396
43.8k
        dist = state->wsize - state->wnext;
397
43.8k
        if (dist > copy) dist = copy;
398
43.8k
        zmemcpy(state->window + state->wnext, end - copy, dist);
399
43.8k
        copy -= dist;
400
43.8k
        if (copy) {
401
2.62k
            zmemcpy(state->window, end - copy, copy);
402
2.62k
            state->wnext = copy;
403
2.62k
            state->whave = state->wsize;
404
2.62k
        }
405
41.2k
        else {
406
41.2k
            state->wnext += dist;
407
41.2k
            if (state->wnext == state->wsize) state->wnext = 0;
408
41.2k
            if (state->whave < state->wsize) state->whave += dist;
409
41.2k
        }
410
43.8k
    }
411
44.2k
    return 0;
412
44.2k
}
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
42.6k
    (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
420
#else
421
#  define UPDATE_CHECK(check, buf, len) adler32(check, buf, len)
422
#endif
423
424
/* check macros for header crc */
425
#ifdef GUNZIP
426
#  define CRC2(check, word) \
427
0
    do { \
428
0
        hbuf[0] = (unsigned char)(word); \
429
0
        hbuf[1] = (unsigned char)((word) >> 8); \
430
0
        check = crc32(check, hbuf, 2); \
431
0
    } while (0)
432
433
#  define CRC4(check, word) \
434
0
    do { \
435
0
        hbuf[0] = (unsigned char)(word); \
436
0
        hbuf[1] = (unsigned char)((word) >> 8); \
437
0
        hbuf[2] = (unsigned char)((word) >> 16); \
438
0
        hbuf[3] = (unsigned char)((word) >> 24); \
439
0
        check = crc32(check, hbuf, 4); \
440
0
    } while (0)
441
#endif
442
443
/* Load registers with state in inflate() for speed */
444
#define LOAD() \
445
102k
    do { \
446
102k
        put = strm->next_out; \
447
102k
        left = strm->avail_out; \
448
102k
        next = strm->next_in; \
449
102k
        have = strm->avail_in; \
450
102k
        hold = state->hold; \
451
102k
        bits = state->bits; \
452
102k
    } while (0)
453
454
/* Restore state from registers in inflate() */
455
#define RESTORE() \
456
102k
    do { \
457
102k
        strm->next_out = put; \
458
102k
        strm->avail_out = left; \
459
102k
        strm->next_in = next; \
460
102k
        strm->avail_in = have; \
461
102k
        state->hold = hold; \
462
102k
        state->bits = bits; \
463
102k
    } 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
1.73M
    do { \
476
1.73M
        if (have == 0) goto inf_leave; \
477
1.73M
        have--; \
478
1.73M
        hold += (unsigned long)(*next++) << bits; \
479
1.73M
        bits += 8; \
480
1.73M
    } 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
795k
    do { \
486
1.40M
        while (bits < (unsigned)(n)) \
487
795k
            PULLBYTE(); \
488
795k
    } while (0)
489
490
/* Return the low n bits of the bit accumulator (n < 16) */
491
#define BITS(n) \
492
4.19M
    ((unsigned)hold & ((1U << (n)) - 1))
493
494
/* Remove n bits from the bit accumulator */
495
#define DROPBITS(n) \
496
3.06M
    do { \
497
3.06M
        hold >>= (n); \
498
3.06M
        bits -= (unsigned)(n); \
499
3.06M
    } while (0)
500
501
/* Remove zero to seven bits as needed to go to a byte boundary */
502
#define BYTEBITS() \
503
8.85k
    do { \
504
8.85k
        hold >>= bits & 7; \
505
8.85k
        bits -= bits & 7; \
506
8.85k
    } 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
44.2k
int ZEXPORT inflate(z_streamp strm, int flush) {
591
44.2k
    struct inflate_state FAR *state;
592
44.2k
    z_const unsigned char FAR *next;    /* next input */
593
44.2k
    unsigned char FAR *put;     /* next output */
594
44.2k
    unsigned have, left;        /* available input and output */
595
44.2k
    unsigned long hold;         /* bit buffer */
596
44.2k
    unsigned bits;              /* bits in bit buffer */
597
44.2k
    unsigned in, out;           /* save starting available input and output */
598
44.2k
    unsigned copy;              /* number of stored or match bytes to copy */
599
44.2k
    unsigned char FAR *from;    /* where to copy match bytes from */
600
44.2k
    code here;                  /* current decoding table entry */
601
44.2k
    code last;                  /* parent table entry */
602
44.2k
    unsigned len;               /* length to copy for repeats, bits to drop */
603
44.2k
    int ret;                    /* return code */
604
44.2k
#ifdef GUNZIP
605
44.2k
    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
606
44.2k
#endif
607
44.2k
    static const unsigned short order[19] = /* permutation of code lengths */
608
44.2k
        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
609
610
44.2k
    if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
611
44.2k
        (strm->next_in == Z_NULL && strm->avail_in != 0))
612
0
        return Z_STREAM_ERROR;
613
614
44.2k
    state = (struct inflate_state FAR *)strm->state;
615
44.2k
    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
616
44.2k
    LOAD();
617
44.2k
    in = have;
618
44.2k
    out = left;
619
44.2k
    ret = Z_OK;
620
44.2k
    for (;;)
621
1.34M
        switch (state->mode) {
622
1.66k
        case HEAD:
623
1.66k
            if (state->wrap == 0) {
624
0
                state->mode = TYPEDO;
625
0
                break;
626
0
            }
627
1.66k
            NEEDBITS(16);
628
1.66k
#ifdef GUNZIP
629
1.66k
            if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
630
0
                if (state->wbits == 0)
631
0
                    state->wbits = 15;
632
0
                state->check = crc32(0L, Z_NULL, 0);
633
0
                CRC2(state->check, hold);
634
0
                INITBITS();
635
0
                state->mode = FLAGS;
636
0
                break;
637
0
            }
638
1.66k
            if (state->head != Z_NULL)
639
0
                state->head->done = -1;
640
1.66k
            if (!(state->wrap & 1) ||   /* check if zlib header allowed */
641
#else
642
            if (
643
#endif
644
1.66k
                ((BITS(8) << 8) + (hold >> 8)) % 31) {
645
0
                strm->msg = (char *)"incorrect header check";
646
0
                state->mode = BAD;
647
0
                break;
648
0
            }
649
1.66k
            if (BITS(4) != Z_DEFLATED) {
650
0
                strm->msg = (char *)"unknown compression method";
651
0
                state->mode = BAD;
652
0
                break;
653
0
            }
654
1.66k
            DROPBITS(4);
655
1.66k
            len = BITS(4) + 8;
656
1.66k
            if (state->wbits == 0)
657
1.66k
                state->wbits = len;
658
1.66k
            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
1.66k
            state->dmax = 1U << len;
664
1.66k
            state->flags = 0;               /* indicate zlib header */
665
1.66k
            Tracev((stderr, "inflate:   zlib header ok\n"));
666
1.66k
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
667
1.66k
            state->mode = hold & 0x200 ? DICTID : TYPE;
668
1.66k
            INITBITS();
669
1.66k
            break;
670
0
#ifdef GUNZIP
671
0
        case FLAGS:
672
0
            NEEDBITS(16);
673
0
            state->flags = (int)(hold);
674
0
            if ((state->flags & 0xff) != Z_DEFLATED) {
675
0
                strm->msg = (char *)"unknown compression method";
676
0
                state->mode = BAD;
677
0
                break;
678
0
            }
679
0
            if (state->flags & 0xe000) {
680
0
                strm->msg = (char *)"unknown header flags set";
681
0
                state->mode = BAD;
682
0
                break;
683
0
            }
684
0
            if (state->head != Z_NULL)
685
0
                state->head->text = (int)((hold >> 8) & 1);
686
0
            if ((state->flags & 0x0200) && (state->wrap & 4))
687
0
                CRC2(state->check, hold);
688
0
            INITBITS();
689
0
            state->mode = TIME;
690
                /* fallthrough */
691
0
        case TIME:
692
0
            NEEDBITS(32);
693
0
            if (state->head != Z_NULL)
694
0
                state->head->time = hold;
695
0
            if ((state->flags & 0x0200) && (state->wrap & 4))
696
0
                CRC4(state->check, hold);
697
0
            INITBITS();
698
0
            state->mode = OS;
699
                /* fallthrough */
700
0
        case OS:
701
0
            NEEDBITS(16);
702
0
            if (state->head != Z_NULL) {
703
0
                state->head->xflags = (int)(hold & 0xff);
704
0
                state->head->os = (int)(hold >> 8);
705
0
            }
706
0
            if ((state->flags & 0x0200) && (state->wrap & 4))
707
0
                CRC2(state->check, hold);
708
0
            INITBITS();
709
0
            state->mode = EXLEN;
710
                /* fallthrough */
711
0
        case EXLEN:
712
0
            if (state->flags & 0x0400) {
713
0
                NEEDBITS(16);
714
0
                state->length = (unsigned)(hold);
715
0
                if (state->head != Z_NULL)
716
0
                    state->head->extra_len = (unsigned)hold;
717
0
                if ((state->flags & 0x0200) && (state->wrap & 4))
718
0
                    CRC2(state->check, hold);
719
0
                INITBITS();
720
0
            }
721
0
            else if (state->head != Z_NULL)
722
0
                state->head->extra = Z_NULL;
723
0
            state->mode = EXTRA;
724
                /* fallthrough */
725
0
        case EXTRA:
726
0
            if (state->flags & 0x0400) {
727
0
                copy = state->length;
728
0
                if (copy > have) copy = have;
729
0
                if (copy) {
730
0
                    if (state->head != Z_NULL &&
731
0
                        state->head->extra != Z_NULL &&
732
0
                        (len = state->head->extra_len - state->length) <
733
0
                            state->head->extra_max) {
734
0
                        zmemcpy(state->head->extra + len, next,
735
0
                                len + copy > state->head->extra_max ?
736
0
                                state->head->extra_max - len : copy);
737
0
                    }
738
0
                    if ((state->flags & 0x0200) && (state->wrap & 4))
739
0
                        state->check = crc32(state->check, next, copy);
740
0
                    have -= copy;
741
0
                    next += copy;
742
0
                    state->length -= copy;
743
0
                }
744
0
                if (state->length) goto inf_leave;
745
0
            }
746
0
            state->length = 0;
747
0
            state->mode = NAME;
748
                /* fallthrough */
749
0
        case NAME:
750
0
            if (state->flags & 0x0800) {
751
0
                if (have == 0) goto inf_leave;
752
0
                copy = 0;
753
0
                do {
754
0
                    len = (unsigned)(next[copy++]);
755
0
                    if (state->head != Z_NULL &&
756
0
                            state->head->name != Z_NULL &&
757
0
                            state->length < state->head->name_max)
758
0
                        state->head->name[state->length++] = (Bytef)len;
759
0
                } while (len && copy < have);
760
0
                if ((state->flags & 0x0200) && (state->wrap & 4))
761
0
                    state->check = crc32(state->check, next, copy);
762
0
                have -= copy;
763
0
                next += copy;
764
0
                if (len) goto inf_leave;
765
0
            }
766
0
            else if (state->head != Z_NULL)
767
0
                state->head->name = Z_NULL;
768
0
            state->length = 0;
769
0
            state->mode = COMMENT;
770
                /* fallthrough */
771
0
        case COMMENT:
772
0
            if (state->flags & 0x1000) {
773
0
                if (have == 0) goto inf_leave;
774
0
                copy = 0;
775
0
                do {
776
0
                    len = (unsigned)(next[copy++]);
777
0
                    if (state->head != Z_NULL &&
778
0
                            state->head->comment != Z_NULL &&
779
0
                            state->length < state->head->comm_max)
780
0
                        state->head->comment[state->length++] = (Bytef)len;
781
0
                } while (len && copy < have);
782
0
                if ((state->flags & 0x0200) && (state->wrap & 4))
783
0
                    state->check = crc32(state->check, next, copy);
784
0
                have -= copy;
785
0
                next += copy;
786
0
                if (len) goto inf_leave;
787
0
            }
788
0
            else if (state->head != Z_NULL)
789
0
                state->head->comment = Z_NULL;
790
0
            state->mode = HCRC;
791
                /* fallthrough */
792
0
        case HCRC:
793
0
            if (state->flags & 0x0200) {
794
0
                NEEDBITS(16);
795
0
                if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
796
0
                    strm->msg = (char *)"header crc mismatch";
797
0
                    state->mode = BAD;
798
0
                    break;
799
0
                }
800
0
                INITBITS();
801
0
            }
802
0
            if (state->head != Z_NULL) {
803
0
                state->head->hcrc = (int)((state->flags >> 9) & 1);
804
0
                state->head->done = 1;
805
0
            }
806
0
            strm->adler = state->check = crc32(0L, Z_NULL, 0);
807
0
            state->mode = TYPE;
808
0
            break;
809
0
#endif
810
0
        case DICTID:
811
0
            NEEDBITS(32);
812
0
            strm->adler = state->check = ZSWAP32(hold);
813
0
            INITBITS();
814
0
            state->mode = DICT;
815
                /* fallthrough */
816
0
        case DICT:
817
0
            if (state->havedict == 0) {
818
0
                RESTORE();
819
0
                return Z_NEED_DICT;
820
0
            }
821
0
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
822
0
            state->mode = TYPE;
823
                /* fallthrough */
824
26.8k
        case TYPE:
825
26.8k
            if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
826
                /* fallthrough */
827
26.8k
        case TYPEDO:
828
26.8k
            if (state->last) {
829
8
                BYTEBITS();
830
8
                state->mode = CHECK;
831
8
                break;
832
8
            }
833
26.8k
            NEEDBITS(3);
834
26.8k
            state->last = BITS(1);
835
26.8k
            DROPBITS(1);
836
26.8k
            switch (BITS(2)) {
837
8.78k
            case 0:                             /* stored block */
838
8.78k
                Tracev((stderr, "inflate:     stored block%s\n",
839
8.78k
                        state->last ? " (last)" : ""));
840
8.78k
                state->mode = STORED;
841
8.78k
                break;
842
10.8k
            case 1:                             /* fixed block */
843
10.8k
                fixedtables(state);
844
10.8k
                Tracev((stderr, "inflate:     fixed codes block%s\n",
845
10.8k
                        state->last ? " (last)" : ""));
846
10.8k
                state->mode = LEN_;             /* decode codes */
847
10.8k
                if (flush == Z_TREES) {
848
0
                    DROPBITS(2);
849
0
                    goto inf_leave;
850
0
                }
851
10.8k
                break;
852
10.8k
            case 2:                             /* dynamic block */
853
7.16k
                Tracev((stderr, "inflate:     dynamic codes block%s\n",
854
7.16k
                        state->last ? " (last)" : ""));
855
7.16k
                state->mode = TABLE;
856
7.16k
                break;
857
3
            case 3:
858
3
                strm->msg = (char *)"invalid block type";
859
3
                state->mode = BAD;
860
26.8k
            }
861
26.8k
            DROPBITS(2);
862
26.8k
            break;
863
8.85k
        case STORED:
864
8.85k
            BYTEBITS();                         /* go to byte boundary */
865
8.85k
            NEEDBITS(32);
866
8.78k
            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
867
4
                strm->msg = (char *)"invalid stored block lengths";
868
4
                state->mode = BAD;
869
4
                break;
870
4
            }
871
8.78k
            state->length = (unsigned)hold & 0xffff;
872
8.78k
            Tracev((stderr, "inflate:       stored length %u\n",
873
8.78k
                    state->length));
874
8.78k
            INITBITS();
875
8.78k
            state->mode = COPY_;
876
8.78k
            if (flush == Z_TREES) goto inf_leave;
877
                /* fallthrough */
878
8.78k
        case COPY_:
879
8.78k
            state->mode = COPY;
880
                /* fallthrough */
881
29.4k
        case COPY:
882
29.4k
            copy = state->length;
883
29.4k
            if (copy) {
884
20.7k
                if (copy > have) copy = have;
885
20.7k
                if (copy > left) copy = left;
886
20.7k
                if (copy == 0) goto inf_leave;
887
13.9k
                zmemcpy(put, next, copy);
888
13.9k
                have -= copy;
889
13.9k
                next += copy;
890
13.9k
                left -= copy;
891
13.9k
                put += copy;
892
13.9k
                state->length -= copy;
893
13.9k
                break;
894
20.7k
            }
895
8.77k
            Tracev((stderr, "inflate:       stored end\n"));
896
8.77k
            state->mode = TYPE;
897
8.77k
            break;
898
7.19k
        case TABLE:
899
7.19k
            NEEDBITS(14);
900
7.16k
            state->nlen = BITS(5) + 257;
901
7.16k
            DROPBITS(5);
902
7.16k
            state->ndist = BITS(5) + 1;
903
7.16k
            DROPBITS(5);
904
7.16k
            state->ncode = BITS(4) + 4;
905
7.16k
            DROPBITS(4);
906
7.16k
#ifndef PKZIP_BUG_WORKAROUND
907
7.16k
            if (state->nlen > 286 || state->ndist > 30) {
908
0
                strm->msg = (char *)"too many length or distance symbols";
909
0
                state->mode = BAD;
910
0
                break;
911
0
            }
912
7.16k
#endif
913
7.16k
            Tracev((stderr, "inflate:       table sizes ok\n"));
914
7.16k
            state->have = 0;
915
7.16k
            state->mode = LENLENS;
916
                /* fallthrough */
917
7.25k
        case LENLENS:
918
129k
            while (state->have < state->ncode) {
919
121k
                NEEDBITS(3);
920
121k
                state->lens[order[state->have++]] = (unsigned short)BITS(3);
921
121k
                DROPBITS(3);
922
121k
            }
923
21.5k
            while (state->have < 19)
924
14.3k
                state->lens[order[state->have++]] = 0;
925
7.16k
            state->next = state->codes;
926
7.16k
            state->lencode = (const code FAR *)(state->next);
927
7.16k
            state->lenbits = 7;
928
7.16k
            ret = inflate_table(CODES, state->lens, 19, &(state->next),
929
7.16k
                                &(state->lenbits), state->work);
930
7.16k
            if (ret) {
931
2
                strm->msg = (char *)"invalid code lengths set";
932
2
                state->mode = BAD;
933
2
                break;
934
2
            }
935
7.16k
            Tracev((stderr, "inflate:       code lengths ok\n"));
936
7.16k
            state->have = 0;
937
7.16k
            state->mode = CODELENS;
938
                /* fallthrough */
939
8.04k
        case CODELENS:
940
1.29M
            while (state->have < state->nlen + state->ndist) {
941
1.89M
                for (;;) {
942
1.89M
                    here = state->lencode[BITS(state->lenbits)];
943
1.89M
                    if ((unsigned)(here.bits) <= bits) break;
944
616k
                    PULLBYTE();
945
616k
                }
946
1.28M
                if (here.val < 16) {
947
1.11M
                    DROPBITS(here.bits);
948
1.11M
                    state->lens[state->have++] = here.val;
949
1.11M
                }
950
164k
                else {
951
164k
                    if (here.val == 16) {
952
114k
                        NEEDBITS(here.bits + 2);
953
114k
                        DROPBITS(here.bits);
954
114k
                        if (state->have == 0) {
955
0
                            strm->msg = (char *)"invalid bit length repeat";
956
0
                            state->mode = BAD;
957
0
                            break;
958
0
                        }
959
114k
                        len = state->lens[state->have - 1];
960
114k
                        copy = 3 + BITS(2);
961
114k
                        DROPBITS(2);
962
114k
                    }
963
50.1k
                    else if (here.val == 17) {
964
35.8k
                        NEEDBITS(here.bits + 3);
965
35.8k
                        DROPBITS(here.bits);
966
35.8k
                        len = 0;
967
35.8k
                        copy = 3 + BITS(3);
968
35.8k
                        DROPBITS(3);
969
35.8k
                    }
970
14.3k
                    else {
971
14.3k
                        NEEDBITS(here.bits + 7);
972
14.3k
                        DROPBITS(here.bits);
973
14.3k
                        len = 0;
974
14.3k
                        copy = 11 + BITS(7);
975
14.3k
                        DROPBITS(7);
976
14.3k
                    }
977
164k
                    if (state->have + copy > state->nlen + state->ndist) {
978
0
                        strm->msg = (char *)"invalid bit length repeat";
979
0
                        state->mode = BAD;
980
0
                        break;
981
0
                    }
982
1.30M
                    while (copy--)
983
1.13M
                        state->lens[state->have++] = (unsigned short)len;
984
164k
                }
985
1.28M
            }
986
987
            /* handle error breaks in while */
988
7.16k
            if (state->mode == BAD) break;
989
990
            /* check for end-of-block code (better have one) */
991
7.16k
            if (state->lens[256] == 0) {
992
0
                strm->msg = (char *)"invalid code -- missing end-of-block";
993
0
                state->mode = BAD;
994
0
                break;
995
0
            }
996
997
            /* build code tables -- note: do not change the lenbits or distbits
998
               values here (9 and 6) without reading the comments in inftrees.h
999
               concerning the ENOUGH constants, which depend on those values */
1000
7.16k
            state->next = state->codes;
1001
7.16k
            state->lencode = (const code FAR *)(state->next);
1002
7.16k
            state->lenbits = 9;
1003
7.16k
            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1004
7.16k
                                &(state->lenbits), state->work);
1005
7.16k
            if (ret) {
1006
2
                strm->msg = (char *)"invalid literal/lengths set";
1007
2
                state->mode = BAD;
1008
2
                break;
1009
2
            }
1010
7.16k
            state->distcode = (const code FAR *)(state->next);
1011
7.16k
            state->distbits = 6;
1012
7.16k
            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1013
7.16k
                            &(state->next), &(state->distbits), state->work);
1014
7.16k
            if (ret) {
1015
1
                strm->msg = (char *)"invalid distances set";
1016
1
                state->mode = BAD;
1017
1
                break;
1018
1
            }
1019
7.16k
            Tracev((stderr, "inflate:       codes ok\n"));
1020
7.16k
            state->mode = LEN_;
1021
7.16k
            if (flush == Z_TREES) goto inf_leave;
1022
                /* fallthrough */
1023
18.0k
        case LEN_:
1024
18.0k
            state->mode = LEN;
1025
                /* fallthrough */
1026
763k
        case LEN:
1027
763k
            if (have >= 6 && left >= 258) {
1028
58.2k
                RESTORE();
1029
58.2k
                inflate_fast(strm, out);
1030
58.2k
                LOAD();
1031
58.2k
                if (state->mode == TYPE)
1032
14.6k
                    state->back = -1;
1033
58.2k
                break;
1034
58.2k
            }
1035
705k
            state->back = 0;
1036
1.19M
            for (;;) {
1037
1.19M
                here = state->lencode[BITS(state->lenbits)];
1038
1.19M
                if ((unsigned)(here.bits) <= bits) break;
1039
493k
                PULLBYTE();
1040
493k
            }
1041
702k
            if (here.op && (here.op & 0xf0) == 0) {
1042
1.79k
                last = here;
1043
2.81k
                for (;;) {
1044
2.81k
                    here = state->lencode[last.val +
1045
2.81k
                            (BITS(last.bits + last.op) >> last.bits)];
1046
2.81k
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1047
1.27k
                    PULLBYTE();
1048
1.27k
                }
1049
1.53k
                DROPBITS(last.bits);
1050
1.53k
                state->back += last.bits;
1051
1.53k
            }
1052
702k
            DROPBITS(here.bits);
1053
702k
            state->back += here.bits;
1054
702k
            state->length = (unsigned)here.val;
1055
702k
            if ((int)(here.op) == 0) {
1056
452k
                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1057
452k
                        "inflate:         literal '%c'\n" :
1058
452k
                        "inflate:         literal 0x%02x\n", here.val));
1059
452k
                state->mode = LIT;
1060
452k
                break;
1061
452k
            }
1062
249k
            if (here.op & 32) {
1063
1.74k
                Tracevv((stderr, "inflate:         end of block\n"));
1064
1.74k
                state->back = -1;
1065
1.74k
                state->mode = TYPE;
1066
1.74k
                break;
1067
1.74k
            }
1068
247k
            if (here.op & 64) {
1069
0
                strm->msg = (char *)"invalid literal/length code";
1070
0
                state->mode = BAD;
1071
0
                break;
1072
0
            }
1073
247k
            state->extra = (unsigned)(here.op) & 15;
1074
247k
            state->mode = LENEXT;
1075
                /* fallthrough */
1076
248k
        case LENEXT:
1077
248k
            if (state->extra) {
1078
230k
                NEEDBITS(state->extra);
1079
229k
                state->length += BITS(state->extra);
1080
229k
                DROPBITS(state->extra);
1081
229k
                state->back += state->extra;
1082
229k
            }
1083
247k
            Tracevv((stderr, "inflate:         length %u\n", state->length));
1084
247k
            state->was = state->length;
1085
247k
            state->mode = DIST;
1086
                /* fallthrough */
1087
248k
        case DIST:
1088
265k
            for (;;) {
1089
265k
                here = state->distcode[BITS(state->distbits)];
1090
265k
                if ((unsigned)(here.bits) <= bits) break;
1091
17.2k
                PULLBYTE();
1092
17.2k
            }
1093
247k
            if ((here.op & 0xf0) == 0) {
1094
726
                last = here;
1095
921
                for (;;) {
1096
921
                    here = state->distcode[last.val +
1097
921
                            (BITS(last.bits + last.op) >> last.bits)];
1098
921
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1099
249
                    PULLBYTE();
1100
249
                }
1101
672
                DROPBITS(last.bits);
1102
672
                state->back += last.bits;
1103
672
            }
1104
247k
            DROPBITS(here.bits);
1105
247k
            state->back += here.bits;
1106
247k
            if (here.op & 64) {
1107
0
                strm->msg = (char *)"invalid distance code";
1108
0
                state->mode = BAD;
1109
0
                break;
1110
0
            }
1111
247k
            state->offset = (unsigned)here.val;
1112
247k
            state->extra = (unsigned)(here.op) & 15;
1113
247k
            state->mode = DISTEXT;
1114
                /* fallthrough */
1115
248k
        case DISTEXT:
1116
248k
            if (state->extra) {
1117
233k
                NEEDBITS(state->extra);
1118
232k
                state->offset += BITS(state->extra);
1119
232k
                DROPBITS(state->extra);
1120
232k
                state->back += state->extra;
1121
232k
            }
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
247k
            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
1130
247k
            state->mode = MATCH;
1131
                /* fallthrough */
1132
316k
        case MATCH:
1133
316k
            if (left == 0) goto inf_leave;
1134
286k
            copy = out - left;
1135
286k
            if (state->offset > copy) {         /* copy from window */
1136
31.1k
                copy = state->offset - copy;
1137
31.1k
                if (copy > state->whave) {
1138
0
                    if (state->sane) {
1139
0
                        strm->msg = (char *)"invalid distance too far back";
1140
0
                        state->mode = BAD;
1141
0
                        break;
1142
0
                    }
1143
#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1144
                    Trace((stderr, "inflate.c too far\n"));
1145
                    copy -= state->whave;
1146
                    if (copy > state->length) copy = state->length;
1147
                    if (copy > left) copy = left;
1148
                    left -= copy;
1149
                    state->length -= copy;
1150
                    do {
1151
                        *put++ = 0;
1152
                    } while (--copy);
1153
                    if (state->length == 0) state->mode = LEN;
1154
                    break;
1155
#endif
1156
0
                }
1157
31.1k
                if (copy > state->wnext) {
1158
598
                    copy -= state->wnext;
1159
598
                    from = state->window + (state->wsize - copy);
1160
598
                }
1161
30.5k
                else
1162
30.5k
                    from = state->window + (state->wnext - copy);
1163
31.1k
                if (copy > state->length) copy = state->length;
1164
31.1k
            }
1165
255k
            else {                              /* copy from output */
1166
255k
                from = put - state->offset;
1167
255k
                copy = state->length;
1168
255k
            }
1169
286k
            if (copy > left) copy = left;
1170
286k
            left -= copy;
1171
286k
            state->length -= copy;
1172
7.69M
            do {
1173
7.69M
                *put++ = *from++;
1174
7.69M
            } while (--copy);
1175
286k
            if (state->length == 0) state->mode = LEN;
1176
286k
            break;
1177
454k
        case LIT:
1178
454k
            if (left == 0) goto inf_leave;
1179
452k
            *put++ = (unsigned char)(state->length);
1180
452k
            left--;
1181
452k
            state->mode = LEN;
1182
452k
            break;
1183
8
        case CHECK:
1184
8
            if (state->wrap) {
1185
8
                NEEDBITS(32);
1186
7
                out -= left;
1187
7
                strm->total_out += out;
1188
7
                state->total += out;
1189
7
                if ((state->wrap & 4) && out)
1190
7
                    strm->adler = state->check =
1191
7
                        UPDATE_CHECK(state->check, put - out, out);
1192
7
                out = left;
1193
7
                if ((state->wrap & 4) && (
1194
7
#ifdef GUNZIP
1195
7
                     state->flags ? hold :
1196
7
#endif
1197
7
                     ZSWAP32(hold)) != state->check) {
1198
7
                    strm->msg = (char *)"incorrect data check";
1199
7
                    state->mode = BAD;
1200
7
                    break;
1201
7
                }
1202
0
                INITBITS();
1203
0
                Tracev((stderr, "inflate:   check matches trailer\n"));
1204
0
            }
1205
0
#ifdef GUNZIP
1206
0
            state->mode = LENGTH;
1207
                /* fallthrough */
1208
0
        case LENGTH:
1209
0
            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
0
#endif
1220
0
            state->mode = DONE;
1221
                /* fallthrough */
1222
0
        case DONE:
1223
0
            ret = Z_STREAM_END;
1224
0
            goto inf_leave;
1225
23
        case BAD:
1226
23
            ret = Z_DATA_ERROR;
1227
23
            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
1.34M
        }
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
44.2k
  inf_leave:
1243
44.2k
    RESTORE();
1244
44.2k
    if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
1245
1.66k
            (state->mode < CHECK || flush != Z_FINISH)))
1246
44.2k
        if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
1247
0
            state->mode = MEM;
1248
0
            return Z_MEM_ERROR;
1249
0
        }
1250
44.2k
    in -= strm->avail_in;
1251
44.2k
    out -= strm->avail_out;
1252
44.2k
    strm->total_in += in;
1253
44.2k
    strm->total_out += out;
1254
44.2k
    state->total += out;
1255
44.2k
    if ((state->wrap & 4) && out)
1256
42.6k
        strm->adler = state->check =
1257
42.6k
            UPDATE_CHECK(state->check, strm->next_out - out, out);
1258
44.2k
    strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
1259
44.2k
                      (state->mode == TYPE ? 128 : 0) +
1260
44.2k
                      (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1261
44.2k
    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1262
3.17k
        ret = Z_BUF_ERROR;
1263
44.2k
    return ret;
1264
44.2k
}
1265
1266
108
int ZEXPORT inflateEnd(z_streamp strm) {
1267
108
    struct inflate_state FAR *state;
1268
108
    if (inflateStateCheck(strm))
1269
5
        return Z_STREAM_ERROR;
1270
103
    state = (struct inflate_state FAR *)strm->state;
1271
103
    if (state->window != Z_NULL) ZFREE(strm, state->window);
1272
103
    ZFREE(strm, strm->state);
1273
103
    strm->state = Z_NULL;
1274
103
    Tracev((stderr, "inflate: end\n"));
1275
103
    return Z_OK;
1276
108
}
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
}