Coverage Report

Created: 2025-07-12 06:21

/src/ots/subprojects/zlib-1.3.1/inflate.c
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Count
Source (jump to first uncovered line)
1
/* inflate.c -- zlib decompression
2
 * Copyright (C) 1995-2022 Mark Adler
3
 * For conditions of distribution and use, see copyright notice in zlib.h
4
 */
5
6
/*
7
 * Change history:
8
 *
9
 * 1.2.beta0    24 Nov 2002
10
 * - First version -- complete rewrite of inflate to simplify code, avoid
11
 *   creation of window when not needed, minimize use of window when it is
12
 *   needed, make inffast.c even faster, implement gzip decoding, and to
13
 *   improve code readability and style over the previous zlib inflate code
14
 *
15
 * 1.2.beta1    25 Nov 2002
16
 * - Use pointers for available input and output checking in inffast.c
17
 * - Remove input and output counters in inffast.c
18
 * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
19
 * - Remove unnecessary second byte pull from length extra in inffast.c
20
 * - Unroll direct copy to three copies per loop in inffast.c
21
 *
22
 * 1.2.beta2    4 Dec 2002
23
 * - Change external routine names to reduce potential conflicts
24
 * - Correct filename to inffixed.h for fixed tables in inflate.c
25
 * - Make hbuf[] unsigned char to match parameter type in inflate.c
26
 * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
27
 *   to avoid negation problem on Alphas (64 bit) in inflate.c
28
 *
29
 * 1.2.beta3    22 Dec 2002
30
 * - Add comments on state->bits assertion in inffast.c
31
 * - Add comments on op field in inftrees.h
32
 * - Fix bug in reuse of allocated window after inflateReset()
33
 * - Remove bit fields--back to byte structure for speed
34
 * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
35
 * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
36
 * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
37
 * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
38
 * - Use local copies of stream next and avail values, as well as local bit
39
 *   buffer and bit count in inflate()--for speed when inflate_fast() not used
40
 *
41
 * 1.2.beta4    1 Jan 2003
42
 * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
43
 * - Move a comment on output buffer sizes from inffast.c to inflate.c
44
 * - Add comments in inffast.c to introduce the inflate_fast() routine
45
 * - Rearrange window copies in inflate_fast() for speed and simplification
46
 * - Unroll last copy for window match in inflate_fast()
47
 * - Use local copies of window variables in inflate_fast() for speed
48
 * - Pull out common wnext == 0 case for speed in inflate_fast()
49
 * - Make op and len in inflate_fast() unsigned for consistency
50
 * - Add FAR to lcode and dcode declarations in inflate_fast()
51
 * - Simplified bad distance check in inflate_fast()
52
 * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
53
 *   source file infback.c to provide a call-back interface to inflate for
54
 *   programs like gzip and unzip -- uses window as output buffer to avoid
55
 *   window copying
56
 *
57
 * 1.2.beta5    1 Jan 2003
58
 * - Improved inflateBack() interface to allow the caller to provide initial
59
 *   input in strm.
60
 * - Fixed stored blocks bug in inflateBack()
61
 *
62
 * 1.2.beta6    4 Jan 2003
63
 * - Added comments in inffast.c on effectiveness of POSTINC
64
 * - Typecasting all around to reduce compiler warnings
65
 * - Changed loops from while (1) or do {} while (1) to for (;;), again to
66
 *   make compilers happy
67
 * - Changed type of window in inflateBackInit() to unsigned char *
68
 *
69
 * 1.2.beta7    27 Jan 2003
70
 * - Changed many types to unsigned or unsigned short to avoid warnings
71
 * - Added inflateCopy() function
72
 *
73
 * 1.2.0        9 Mar 2003
74
 * - Changed inflateBack() interface to provide separate opaque descriptors
75
 *   for the in() and out() functions
76
 * - Changed inflateBack() argument and in_func typedef to swap the length
77
 *   and buffer address return values for the input function
78
 * - Check next_in and next_out for Z_NULL on entry to inflate()
79
 *
80
 * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
81
 */
82
83
#include "zutil.h"
84
#include "inftrees.h"
85
#include "inflate.h"
86
#include "inffast.h"
87
88
#ifdef MAKEFIXED
89
#  ifndef BUILDFIXED
90
#    define BUILDFIXED
91
#  endif
92
#endif
93
94
9.19k
local int inflateStateCheck(z_streamp strm) {
95
9.19k
    struct inflate_state FAR *state;
96
9.19k
    if (strm == Z_NULL ||
97
9.19k
        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
98
0
        return 1;
99
9.19k
    state = (struct inflate_state FAR *)strm->state;
100
9.19k
    if (state == Z_NULL || state->strm != strm ||
101
9.19k
        state->mode < HEAD || state->mode > SYNC)
102
0
        return 1;
103
9.19k
    return 0;
104
9.19k
}
105
106
1.82k
int ZEXPORT inflateResetKeep(z_streamp strm) {
107
1.82k
    struct inflate_state FAR *state;
108
109
1.82k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
110
1.82k
    state = (struct inflate_state FAR *)strm->state;
111
1.82k
    strm->total_in = strm->total_out = state->total = 0;
112
1.82k
    strm->msg = Z_NULL;
113
1.82k
    if (state->wrap)        /* to support ill-conceived Java test suite */
114
1.82k
        strm->adler = state->wrap & 1;
115
1.82k
    state->mode = HEAD;
116
1.82k
    state->last = 0;
117
1.82k
    state->havedict = 0;
118
1.82k
    state->flags = -1;
119
1.82k
    state->dmax = 32768U;
120
1.82k
    state->head = Z_NULL;
121
1.82k
    state->hold = 0;
122
1.82k
    state->bits = 0;
123
1.82k
    state->lencode = state->distcode = state->next = state->codes;
124
1.82k
    state->sane = 1;
125
1.82k
    state->back = -1;
126
1.82k
    Tracev((stderr, "inflate: reset\n"));
127
1.82k
    return Z_OK;
128
1.82k
}
129
130
1.82k
int ZEXPORT inflateReset(z_streamp strm) {
131
1.82k
    struct inflate_state FAR *state;
132
133
1.82k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
134
1.82k
    state = (struct inflate_state FAR *)strm->state;
135
1.82k
    state->wsize = 0;
136
1.82k
    state->whave = 0;
137
1.82k
    state->wnext = 0;
138
1.82k
    return inflateResetKeep(strm);
139
1.82k
}
140
141
1.82k
int ZEXPORT inflateReset2(z_streamp strm, int windowBits) {
142
1.82k
    int wrap;
143
1.82k
    struct inflate_state FAR *state;
144
145
    /* get the state */
146
1.82k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
147
1.82k
    state = (struct inflate_state FAR *)strm->state;
148
149
    /* extract wrap request from windowBits parameter */
150
1.82k
    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
1.82k
    else {
157
1.82k
        wrap = (windowBits >> 4) + 5;
158
1.82k
#ifdef GUNZIP
159
1.82k
        if (windowBits < 48)
160
1.82k
            windowBits &= 15;
161
1.82k
#endif
162
1.82k
    }
163
164
    /* set number of window bits, free window if different */
165
1.82k
    if (windowBits && (windowBits < 8 || windowBits > 15))
166
0
        return Z_STREAM_ERROR;
167
1.82k
    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
1.82k
    state->wrap = wrap;
174
1.82k
    state->wbits = (unsigned)windowBits;
175
1.82k
    return inflateReset(strm);
176
1.82k
}
177
178
int ZEXPORT inflateInit2_(z_streamp strm, int windowBits,
179
1.82k
                          const char *version, int stream_size) {
180
1.82k
    int ret;
181
1.82k
    struct inflate_state FAR *state;
182
183
1.82k
    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
184
1.82k
        stream_size != (int)(sizeof(z_stream)))
185
0
        return Z_VERSION_ERROR;
186
1.82k
    if (strm == Z_NULL) return Z_STREAM_ERROR;
187
1.82k
    strm->msg = Z_NULL;                 /* in case we return an error */
188
1.82k
    if (strm->zalloc == (alloc_func)0) {
189
#ifdef Z_SOLO
190
        return Z_STREAM_ERROR;
191
#else
192
1.82k
        strm->zalloc = zcalloc;
193
1.82k
        strm->opaque = (voidpf)0;
194
1.82k
#endif
195
1.82k
    }
196
1.82k
    if (strm->zfree == (free_func)0)
197
#ifdef Z_SOLO
198
        return Z_STREAM_ERROR;
199
#else
200
1.82k
        strm->zfree = zcfree;
201
1.82k
#endif
202
1.82k
    state = (struct inflate_state FAR *)
203
1.82k
            ZALLOC(strm, 1, sizeof(struct inflate_state));
204
1.82k
    if (state == Z_NULL) return Z_MEM_ERROR;
205
1.82k
    Tracev((stderr, "inflate: allocated\n"));
206
1.82k
    strm->state = (struct internal_state FAR *)state;
207
1.82k
    state->strm = strm;
208
1.82k
    state->window = Z_NULL;
209
1.82k
    state->mode = HEAD;     /* to pass state test in inflateReset2() */
210
1.82k
    ret = inflateReset2(strm, windowBits);
211
1.82k
    if (ret != Z_OK) {
212
0
        ZFREE(strm, state);
213
0
        strm->state = Z_NULL;
214
0
    }
215
1.82k
    return ret;
216
1.82k
}
217
218
int ZEXPORT inflateInit_(z_streamp strm, const char *version,
219
1.82k
                         int stream_size) {
220
1.82k
    return inflateInit2_(strm, DEF_WBITS, version, stream_size);
221
1.82k
}
222
223
0
int ZEXPORT inflatePrime(z_streamp strm, int bits, int value) {
224
0
    struct inflate_state FAR *state;
225
226
0
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
227
0
    if (bits == 0)
228
0
        return Z_OK;
229
0
    state = (struct inflate_state FAR *)strm->state;
230
0
    if (bits < 0) {
231
0
        state->hold = 0;
232
0
        state->bits = 0;
233
0
        return Z_OK;
234
0
    }
235
0
    if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR;
236
0
    value &= (1L << bits) - 1;
237
0
    state->hold += (unsigned)value << state->bits;
238
0
    state->bits += (uInt)bits;
239
0
    return Z_OK;
240
0
}
241
242
/*
243
   Return state with length and distance decoding tables and index sizes set to
244
   fixed code decoding.  Normally this returns fixed tables from inffixed.h.
245
   If BUILDFIXED is defined, then instead this routine builds the tables the
246
   first time it's called, and returns those tables the first time and
247
   thereafter.  This reduces the size of the code by about 2K bytes, in
248
   exchange for a little execution time.  However, BUILDFIXED should not be
249
   used for threaded applications, since the rewriting of the tables and virgin
250
   may not be thread-safe.
251
 */
252
1.39k
local void fixedtables(struct inflate_state FAR *state) {
253
#ifdef BUILDFIXED
254
    static int virgin = 1;
255
    static code *lenfix, *distfix;
256
    static code fixed[544];
257
258
    /* build fixed huffman tables if first call (may not be thread safe) */
259
    if (virgin) {
260
        unsigned sym, bits;
261
        static code *next;
262
263
        /* literal/length table */
264
        sym = 0;
265
        while (sym < 144) state->lens[sym++] = 8;
266
        while (sym < 256) state->lens[sym++] = 9;
267
        while (sym < 280) state->lens[sym++] = 7;
268
        while (sym < 288) state->lens[sym++] = 8;
269
        next = fixed;
270
        lenfix = next;
271
        bits = 9;
272
        inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
273
274
        /* distance table */
275
        sym = 0;
276
        while (sym < 32) state->lens[sym++] = 5;
277
        distfix = next;
278
        bits = 5;
279
        inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
280
281
        /* do this just once */
282
        virgin = 0;
283
    }
284
#else /* !BUILDFIXED */
285
1.39k
#   include "inffixed.h"
286
1.39k
#endif /* BUILDFIXED */
287
1.39k
    state->lencode = lenfix;
288
1.39k
    state->lenbits = 9;
289
1.39k
    state->distcode = distfix;
290
1.39k
    state->distbits = 5;
291
1.39k
}
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
140
local int updatewindow(z_streamp strm, const Bytef *end, unsigned copy) {
369
140
    struct inflate_state FAR *state;
370
140
    unsigned dist;
371
372
140
    state = (struct inflate_state FAR *)strm->state;
373
374
    /* if it hasn't been done already, allocate space for the window */
375
140
    if (state->window == Z_NULL) {
376
70
        state->window = (unsigned char FAR *)
377
70
                        ZALLOC(strm, 1U << state->wbits,
378
70
                               sizeof(unsigned char));
379
70
        if (state->window == Z_NULL) return 1;
380
70
    }
381
382
    /* if window not in use yet, initialize */
383
140
    if (state->wsize == 0) {
384
70
        state->wsize = 1U << state->wbits;
385
70
        state->wnext = 0;
386
70
        state->whave = 0;
387
70
    }
388
389
    /* copy state->wsize or less output bytes into the circular window */
390
140
    if (copy >= state->wsize) {
391
9
        zmemcpy(state->window, end - state->wsize, state->wsize);
392
9
        state->wnext = 0;
393
9
        state->whave = state->wsize;
394
9
    }
395
131
    else {
396
131
        dist = state->wsize - state->wnext;
397
131
        if (dist > copy) dist = copy;
398
131
        zmemcpy(state->window + state->wnext, end - copy, dist);
399
131
        copy -= dist;
400
131
        if (copy) {
401
0
            zmemcpy(state->window, end - copy, copy);
402
0
            state->wnext = copy;
403
0
            state->whave = state->wsize;
404
0
        }
405
131
        else {
406
131
            state->wnext += dist;
407
131
            if (state->wnext == state->wsize) state->wnext = 0;
408
131
            if (state->whave < state->wsize) state->whave += dist;
409
131
        }
410
131
    }
411
140
    return 0;
412
140
}
413
414
/* Macros for inflate(): */
415
416
/* check function to use adler32() for zlib or crc32() for gzip */
417
#ifdef GUNZIP
418
#  define UPDATE_CHECK(check, buf, len) \
419
1.75k
    (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
2.52k
    do { \
446
2.52k
        put = strm->next_out; \
447
2.52k
        left = strm->avail_out; \
448
2.52k
        next = strm->next_in; \
449
2.52k
        have = strm->avail_in; \
450
2.52k
        hold = state->hold; \
451
2.52k
        bits = state->bits; \
452
2.52k
    } while (0)
453
454
/* Restore state from registers in inflate() */
455
#define RESTORE() \
456
2.52k
    do { \
457
2.52k
        strm->next_out = put; \
458
2.52k
        strm->avail_out = left; \
459
2.52k
        strm->next_in = next; \
460
2.52k
        strm->avail_in = have; \
461
2.52k
        state->hold = hold; \
462
2.52k
        state->bits = bits; \
463
2.52k
    } while (0)
464
465
/* Clear the input bit accumulator */
466
#define INITBITS() \
467
3.40k
    do { \
468
3.40k
        hold = 0; \
469
3.40k
        bits = 0; \
470
3.40k
    } 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
145k
    do { \
476
145k
        if (have == 0) goto inf_leave; \
477
145k
        have--; \
478
145k
        hold += (unsigned long)(*next++) << bits; \
479
145k
        bits += 8; \
480
145k
    } 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
39.6k
    do { \
486
65.5k
        while (bits < (unsigned)(n)) \
487
39.6k
            PULLBYTE(); \
488
39.6k
    } while (0)
489
490
/* Return the low n bits of the bit accumulator (n < 16) */
491
#define BITS(n) \
492
361k
    ((unsigned)hold & ((1U << (n)) - 1))
493
494
/* Remove n bits from the bit accumulator */
495
#define DROPBITS(n) \
496
238k
    do { \
497
238k
        hold >>= (n); \
498
238k
        bits -= (unsigned)(n); \
499
238k
    } while (0)
500
501
/* Remove zero to seven bits as needed to go to a byte boundary */
502
#define BYTEBITS() \
503
1.65k
    do { \
504
1.65k
        hold >>= bits & 7; \
505
1.65k
        bits -= bits & 7; \
506
1.65k
    } 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
1.90k
int ZEXPORT inflate(z_streamp strm, int flush) {
591
1.90k
    struct inflate_state FAR *state;
592
1.90k
    z_const unsigned char FAR *next;    /* next input */
593
1.90k
    unsigned char FAR *put;     /* next output */
594
1.90k
    unsigned have, left;        /* available input and output */
595
1.90k
    unsigned long hold;         /* bit buffer */
596
1.90k
    unsigned bits;              /* bits in bit buffer */
597
1.90k
    unsigned in, out;           /* save starting available input and output */
598
1.90k
    unsigned copy;              /* number of stored or match bytes to copy */
599
1.90k
    unsigned char FAR *from;    /* where to copy match bytes from */
600
1.90k
    code here;                  /* current decoding table entry */
601
1.90k
    code last;                  /* parent table entry */
602
1.90k
    unsigned len;               /* length to copy for repeats, bits to drop */
603
1.90k
    int ret;                    /* return code */
604
1.90k
#ifdef GUNZIP
605
1.90k
    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
606
1.90k
#endif
607
1.90k
    static const unsigned short order[19] = /* permutation of code lengths */
608
1.90k
        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
609
610
1.90k
    if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
611
1.90k
        (strm->next_in == Z_NULL && strm->avail_in != 0))
612
0
        return Z_STREAM_ERROR;
613
614
1.90k
    state = (struct inflate_state FAR *)strm->state;
615
1.90k
    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
616
1.90k
    LOAD();
617
1.90k
    in = have;
618
1.90k
    out = left;
619
1.90k
    ret = Z_OK;
620
1.90k
    for (;;)
621
165k
        switch (state->mode) {
622
1.82k
        case HEAD:
623
1.82k
            if (state->wrap == 0) {
624
0
                state->mode = TYPEDO;
625
0
                break;
626
0
            }
627
1.82k
            NEEDBITS(16);
628
1.82k
#ifdef GUNZIP
629
1.82k
            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
1.82k
            if (state->head != Z_NULL)
639
0
                state->head->done = -1;
640
1.82k
            if (!(state->wrap & 1) ||   /* check if zlib header allowed */
641
#else
642
            if (
643
#endif
644
1.82k
                ((BITS(8) << 8) + (hold >> 8)) % 31) {
645
2
                strm->msg = (char *)"incorrect header check";
646
2
                state->mode = BAD;
647
2
                break;
648
2
            }
649
1.82k
            if (BITS(4) != Z_DEFLATED) {
650
1
                strm->msg = (char *)"unknown compression method";
651
1
                state->mode = BAD;
652
1
                break;
653
1
            }
654
1.81k
            DROPBITS(4);
655
1.81k
            len = BITS(4) + 8;
656
1.81k
            if (state->wbits == 0)
657
0
                state->wbits = len;
658
1.81k
            if (len > 15 || len > state->wbits) {
659
1
                strm->msg = (char *)"invalid window size";
660
1
                state->mode = BAD;
661
1
                break;
662
1
            }
663
1.81k
            state->dmax = 1U << len;
664
1.81k
            state->flags = 0;               /* indicate zlib header */
665
1.81k
            Tracev((stderr, "inflate:   zlib header ok\n"));
666
1.81k
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
667
1.81k
            state->mode = hold & 0x200 ? DICTID : TYPE;
668
1.81k
            INITBITS();
669
1.81k
            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
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
3.69k
        case TYPE:
825
3.69k
            if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
826
                /* fallthrough */
827
3.69k
        case TYPEDO:
828
3.69k
            if (state->last) {
829
1.61k
                BYTEBITS();
830
1.61k
                state->mode = CHECK;
831
1.61k
                break;
832
1.61k
            }
833
2.08k
            NEEDBITS(3);
834
2.07k
            state->last = BITS(1);
835
2.07k
            DROPBITS(1);
836
2.07k
            switch (BITS(2)) {
837
32
            case 0:                             /* stored block */
838
32
                Tracev((stderr, "inflate:     stored block%s\n",
839
32
                        state->last ? " (last)" : ""));
840
32
                state->mode = STORED;
841
32
                break;
842
1.39k
            case 1:                             /* fixed block */
843
1.39k
                fixedtables(state);
844
1.39k
                Tracev((stderr, "inflate:     fixed codes block%s\n",
845
1.39k
                        state->last ? " (last)" : ""));
846
1.39k
                state->mode = LEN_;             /* decode codes */
847
1.39k
                if (flush == Z_TREES) {
848
0
                    DROPBITS(2);
849
0
                    goto inf_leave;
850
0
                }
851
1.39k
                break;
852
1.39k
            case 2:                             /* dynamic block */
853
652
                Tracev((stderr, "inflate:     dynamic codes block%s\n",
854
652
                        state->last ? " (last)" : ""));
855
652
                state->mode = TABLE;
856
652
                break;
857
1
            case 3:
858
1
                strm->msg = (char *)"invalid block type";
859
1
                state->mode = BAD;
860
2.07k
            }
861
2.07k
            DROPBITS(2);
862
2.07k
            break;
863
35
        case STORED:
864
35
            BYTEBITS();                         /* go to byte boundary */
865
35
            NEEDBITS(32);
866
29
            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
867
6
                strm->msg = (char *)"invalid stored block lengths";
868
6
                state->mode = BAD;
869
6
                break;
870
6
            }
871
23
            state->length = (unsigned)hold & 0xffff;
872
23
            Tracev((stderr, "inflate:       stored length %u\n",
873
23
                    state->length));
874
23
            INITBITS();
875
23
            state->mode = COPY_;
876
23
            if (flush == Z_TREES) goto inf_leave;
877
                /* fallthrough */
878
23
        case COPY_:
879
23
            state->mode = COPY;
880
                /* fallthrough */
881
30
        case COPY:
882
30
            copy = state->length;
883
30
            if (copy) {
884
9
                if (copy > have) copy = have;
885
9
                if (copy > left) copy = left;
886
9
                if (copy == 0) goto inf_leave;
887
5
                zmemcpy(put, next, copy);
888
5
                have -= copy;
889
5
                next += copy;
890
5
                left -= copy;
891
5
                put += copy;
892
5
                state->length -= copy;
893
5
                break;
894
9
            }
895
21
            Tracev((stderr, "inflate:       stored end\n"));
896
21
            state->mode = TYPE;
897
21
            break;
898
653
        case TABLE:
899
653
            NEEDBITS(14);
900
651
            state->nlen = BITS(5) + 257;
901
651
            DROPBITS(5);
902
651
            state->ndist = BITS(5) + 1;
903
651
            DROPBITS(5);
904
651
            state->ncode = BITS(4) + 4;
905
651
            DROPBITS(4);
906
651
#ifndef PKZIP_BUG_WORKAROUND
907
651
            if (state->nlen > 286 || state->ndist > 30) {
908
2
                strm->msg = (char *)"too many length or distance symbols";
909
2
                state->mode = BAD;
910
2
                break;
911
2
            }
912
649
#endif
913
649
            Tracev((stderr, "inflate:       table sizes ok\n"));
914
649
            state->have = 0;
915
649
            state->mode = LENLENS;
916
                /* fallthrough */
917
650
        case LENLENS:
918
10.8k
            while (state->have < state->ncode) {
919
10.1k
                NEEDBITS(3);
920
10.1k
                state->lens[order[state->have++]] = (unsigned short)BITS(3);
921
10.1k
                DROPBITS(3);
922
10.1k
            }
923
2.80k
            while (state->have < 19)
924
2.15k
                state->lens[order[state->have++]] = 0;
925
648
            state->next = state->codes;
926
648
            state->lencode = (const code FAR *)(state->next);
927
648
            state->lenbits = 7;
928
648
            ret = inflate_table(CODES, state->lens, 19, &(state->next),
929
648
                                &(state->lenbits), state->work);
930
648
            if (ret) {
931
9
                strm->msg = (char *)"invalid code lengths set";
932
9
                state->mode = BAD;
933
9
                break;
934
9
            }
935
639
            Tracev((stderr, "inflate:       code lengths ok\n"));
936
639
            state->have = 0;
937
639
            state->mode = CODELENS;
938
                /* fallthrough */
939
651
        case CODELENS:
940
98.5k
            while (state->have < state->nlen + state->ndist) {
941
135k
                for (;;) {
942
135k
                    here = state->lencode[BITS(state->lenbits)];
943
135k
                    if ((unsigned)(here.bits) <= bits) break;
944
37.7k
                    PULLBYTE();
945
37.7k
                }
946
97.9k
                if (here.val < 16) {
947
85.8k
                    DROPBITS(here.bits);
948
85.8k
                    state->lens[state->have++] = here.val;
949
85.8k
                }
950
12.0k
                else {
951
12.0k
                    if (here.val == 16) {
952
7.66k
                        NEEDBITS(here.bits + 2);
953
7.65k
                        DROPBITS(here.bits);
954
7.65k
                        if (state->have == 0) {
955
1
                            strm->msg = (char *)"invalid bit length repeat";
956
1
                            state->mode = BAD;
957
1
                            break;
958
1
                        }
959
7.65k
                        len = state->lens[state->have - 1];
960
7.65k
                        copy = 3 + BITS(2);
961
7.65k
                        DROPBITS(2);
962
7.65k
                    }
963
4.42k
                    else if (here.val == 17) {
964
3.31k
                        NEEDBITS(here.bits + 3);
965
3.31k
                        DROPBITS(here.bits);
966
3.31k
                        len = 0;
967
3.31k
                        copy = 3 + BITS(3);
968
3.31k
                        DROPBITS(3);
969
3.31k
                    }
970
1.10k
                    else {
971
1.10k
                        NEEDBITS(here.bits + 7);
972
1.10k
                        DROPBITS(here.bits);
973
1.10k
                        len = 0;
974
1.10k
                        copy = 11 + BITS(7);
975
1.10k
                        DROPBITS(7);
976
1.10k
                    }
977
12.0k
                    if (state->have + copy > state->nlen + state->ndist) {
978
12
                        strm->msg = (char *)"invalid bit length repeat";
979
12
                        state->mode = BAD;
980
12
                        break;
981
12
                    }
982
111k
                    while (copy--)
983
99.3k
                        state->lens[state->have++] = (unsigned short)len;
984
12.0k
                }
985
97.9k
            }
986
987
            /* handle error breaks in while */
988
627
            if (state->mode == BAD) break;
989
990
            /* check for end-of-block code (better have one) */
991
614
            if (state->lens[256] == 0) {
992
6
                strm->msg = (char *)"invalid code -- missing end-of-block";
993
6
                state->mode = BAD;
994
6
                break;
995
6
            }
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
608
            state->next = state->codes;
1001
608
            state->lencode = (const code FAR *)(state->next);
1002
608
            state->lenbits = 9;
1003
608
            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1004
608
                                &(state->lenbits), state->work);
1005
608
            if (ret) {
1006
10
                strm->msg = (char *)"invalid literal/lengths set";
1007
10
                state->mode = BAD;
1008
10
                break;
1009
10
            }
1010
598
            state->distcode = (const code FAR *)(state->next);
1011
598
            state->distbits = 6;
1012
598
            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1013
598
                            &(state->next), &(state->distbits), state->work);
1014
598
            if (ret) {
1015
17
                strm->msg = (char *)"invalid distances set";
1016
17
                state->mode = BAD;
1017
17
                break;
1018
17
            }
1019
581
            Tracev((stderr, "inflate:       codes ok\n"));
1020
581
            state->mode = LEN_;
1021
581
            if (flush == Z_TREES) goto inf_leave;
1022
                /* fallthrough */
1023
1.97k
        case LEN_:
1024
1.97k
            state->mode = LEN;
1025
                /* fallthrough */
1026
86.2k
        case LEN:
1027
86.2k
            if (have >= 6 && left >= 258) {
1028
620
                RESTORE();
1029
620
                inflate_fast(strm, out);
1030
620
                LOAD();
1031
620
                if (state->mode == TYPE)
1032
236
                    state->back = -1;
1033
620
                break;
1034
620
            }
1035
85.6k
            state->back = 0;
1036
161k
            for (;;) {
1037
161k
                here = state->lencode[BITS(state->lenbits)];
1038
161k
                if ((unsigned)(here.bits) <= bits) break;
1039
75.9k
                PULLBYTE();
1040
75.9k
            }
1041
85.6k
            if (here.op && (here.op & 0xf0) == 0) {
1042
431
                last = here;
1043
503
                for (;;) {
1044
503
                    here = state->lencode[last.val +
1045
503
                            (BITS(last.bits + last.op) >> last.bits)];
1046
503
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1047
78
                    PULLBYTE();
1048
78
                }
1049
425
                DROPBITS(last.bits);
1050
425
                state->back += last.bits;
1051
425
            }
1052
85.6k
            DROPBITS(here.bits);
1053
85.6k
            state->back += here.bits;
1054
85.6k
            state->length = (unsigned)here.val;
1055
85.6k
            if ((int)(here.op) == 0) {
1056
71.2k
                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1057
71.2k
                        "inflate:         literal '%c'\n" :
1058
71.2k
                        "inflate:         literal 0x%02x\n", here.val));
1059
71.2k
                state->mode = LIT;
1060
71.2k
                break;
1061
71.2k
            }
1062
14.4k
            if (here.op & 32) {
1063
1.62k
                Tracevv((stderr, "inflate:         end of block\n"));
1064
1.62k
                state->back = -1;
1065
1.62k
                state->mode = TYPE;
1066
1.62k
                break;
1067
1.62k
            }
1068
12.7k
            if (here.op & 64) {
1069
1
                strm->msg = (char *)"invalid literal/length code";
1070
1
                state->mode = BAD;
1071
1
                break;
1072
1
            }
1073
12.7k
            state->extra = (unsigned)(here.op) & 15;
1074
12.7k
            state->mode = LENEXT;
1075
                /* fallthrough */
1076
12.7k
        case LENEXT:
1077
12.7k
            if (state->extra) {
1078
1.34k
                NEEDBITS(state->extra);
1079
1.34k
                state->length += BITS(state->extra);
1080
1.34k
                DROPBITS(state->extra);
1081
1.34k
                state->back += state->extra;
1082
1.34k
            }
1083
12.7k
            Tracevv((stderr, "inflate:         length %u\n", state->length));
1084
12.7k
            state->was = state->length;
1085
12.7k
            state->mode = DIST;
1086
                /* fallthrough */
1087
12.7k
        case DIST:
1088
18.9k
            for (;;) {
1089
18.9k
                here = state->distcode[BITS(state->distbits)];
1090
18.9k
                if ((unsigned)(here.bits) <= bits) break;
1091
6.21k
                PULLBYTE();
1092
6.21k
            }
1093
12.7k
            if ((here.op & 0xf0) == 0) {
1094
118
                last = here;
1095
148
                for (;;) {
1096
148
                    here = state->distcode[last.val +
1097
148
                            (BITS(last.bits + last.op) >> last.bits)];
1098
148
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1099
32
                    PULLBYTE();
1100
32
                }
1101
116
                DROPBITS(last.bits);
1102
116
                state->back += last.bits;
1103
116
            }
1104
12.7k
            DROPBITS(here.bits);
1105
12.7k
            state->back += here.bits;
1106
12.7k
            if (here.op & 64) {
1107
3
                strm->msg = (char *)"invalid distance code";
1108
3
                state->mode = BAD;
1109
3
                break;
1110
3
            }
1111
12.7k
            state->offset = (unsigned)here.val;
1112
12.7k
            state->extra = (unsigned)(here.op) & 15;
1113
12.7k
            state->mode = DISTEXT;
1114
                /* fallthrough */
1115
12.7k
        case DISTEXT:
1116
12.7k
            if (state->extra) {
1117
9.87k
                NEEDBITS(state->extra);
1118
9.86k
                state->offset += BITS(state->extra);
1119
9.86k
                DROPBITS(state->extra);
1120
9.86k
                state->back += state->extra;
1121
9.86k
            }
1122
#ifdef INFLATE_STRICT
1123
            if (state->offset > state->dmax) {
1124
                strm->msg = (char *)"invalid distance too far back";
1125
                state->mode = BAD;
1126
                break;
1127
            }
1128
#endif
1129
12.7k
            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
1130
12.7k
            state->mode = MATCH;
1131
                /* fallthrough */
1132
12.8k
        case MATCH:
1133
12.8k
            if (left == 0) goto inf_leave;
1134
12.7k
            copy = out - left;
1135
12.7k
            if (state->offset > copy) {         /* copy from window */
1136
22
                copy = state->offset - copy;
1137
22
                if (copy > state->whave) {
1138
22
                    if (state->sane) {
1139
22
                        strm->msg = (char *)"invalid distance too far back";
1140
22
                        state->mode = BAD;
1141
22
                        break;
1142
22
                    }
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
22
                }
1157
0
                if (copy > state->wnext) {
1158
0
                    copy -= state->wnext;
1159
0
                    from = state->window + (state->wsize - copy);
1160
0
                }
1161
0
                else
1162
0
                    from = state->window + (state->wnext - copy);
1163
0
                if (copy > state->length) copy = state->length;
1164
0
            }
1165
12.7k
            else {                              /* copy from output */
1166
12.7k
                from = put - state->offset;
1167
12.7k
                copy = state->length;
1168
12.7k
            }
1169
12.7k
            if (copy > left) copy = left;
1170
12.7k
            left -= copy;
1171
12.7k
            state->length -= copy;
1172
78.6k
            do {
1173
78.6k
                *put++ = *from++;
1174
78.6k
            } while (--copy);
1175
12.7k
            if (state->length == 0) state->mode = LEN;
1176
12.7k
            break;
1177
71.2k
        case LIT:
1178
71.2k
            if (left == 0) goto inf_leave;
1179
71.2k
            *put++ = (unsigned char)(state->length);
1180
71.2k
            left--;
1181
71.2k
            state->mode = LEN;
1182
71.2k
            break;
1183
1.62k
        case CHECK:
1184
1.62k
            if (state->wrap) {
1185
1.62k
                NEEDBITS(32);
1186
1.61k
                out -= left;
1187
1.61k
                strm->total_out += out;
1188
1.61k
                state->total += out;
1189
1.61k
                if ((state->wrap & 4) && out)
1190
1.61k
                    strm->adler = state->check =
1191
1.61k
                        UPDATE_CHECK(state->check, put - out, out);
1192
1.61k
                out = left;
1193
1.61k
                if ((state->wrap & 4) && (
1194
1.61k
#ifdef GUNZIP
1195
1.61k
                     state->flags ? hold :
1196
1.61k
#endif
1197
1.61k
                     ZSWAP32(hold)) != state->check) {
1198
49
                    strm->msg = (char *)"incorrect data check";
1199
49
                    state->mode = BAD;
1200
49
                    break;
1201
49
                }
1202
1.56k
                INITBITS();
1203
1.56k
                Tracev((stderr, "inflate:   check matches trailer\n"));
1204
1.56k
            }
1205
1.56k
#ifdef GUNZIP
1206
1.56k
            state->mode = LENGTH;
1207
                /* fallthrough */
1208
1.56k
        case LENGTH:
1209
1.56k
            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
1.56k
#endif
1220
1.56k
            state->mode = DONE;
1221
                /* fallthrough */
1222
1.56k
        case DONE:
1223
1.56k
            ret = Z_STREAM_END;
1224
1.56k
            goto inf_leave;
1225
175
        case BAD:
1226
175
            ret = Z_DATA_ERROR;
1227
175
            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
165k
        }
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
1.90k
  inf_leave:
1243
1.90k
    RESTORE();
1244
1.90k
    if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
1245
1.83k
            (state->mode < CHECK || flush != Z_FINISH)))
1246
140
        if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
1247
0
            state->mode = MEM;
1248
0
            return Z_MEM_ERROR;
1249
0
        }
1250
1.90k
    in -= strm->avail_in;
1251
1.90k
    out -= strm->avail_out;
1252
1.90k
    strm->total_in += in;
1253
1.90k
    strm->total_out += out;
1254
1.90k
    state->total += out;
1255
1.90k
    if ((state->wrap & 4) && out)
1256
138
        strm->adler = state->check =
1257
138
            UPDATE_CHECK(state->check, strm->next_out - out, out);
1258
1.90k
    strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
1259
1.90k
                      (state->mode == TYPE ? 128 : 0) +
1260
1.90k
                      (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1261
1.90k
    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1262
82
        ret = Z_BUF_ERROR;
1263
1.90k
    return ret;
1264
1.90k
}
1265
1266
1.82k
int ZEXPORT inflateEnd(z_streamp strm) {
1267
1.82k
    struct inflate_state FAR *state;
1268
1.82k
    if (inflateStateCheck(strm))
1269
0
        return Z_STREAM_ERROR;
1270
1.82k
    state = (struct inflate_state FAR *)strm->state;
1271
1.82k
    if (state->window != Z_NULL) ZFREE(strm, state->window);
1272
1.82k
    ZFREE(strm, strm->state);
1273
1.82k
    strm->state = Z_NULL;
1274
1.82k
    Tracev((stderr, "inflate: end\n"));
1275
1.82k
    return Z_OK;
1276
1.82k
}
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
}