Coverage Report

Created: 2024-02-06 06:20

/src/libgit2/deps/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
4.36M
local int inflateStateCheck(z_streamp strm) {
95
4.36M
    struct inflate_state FAR *state;
96
4.36M
    if (strm == Z_NULL ||
97
4.36M
        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
98
0
        return 1;
99
4.36M
    state = (struct inflate_state FAR *)strm->state;
100
4.36M
    if (state == Z_NULL || state->strm != strm ||
101
4.36M
        state->mode < HEAD || state->mode > SYNC)
102
0
        return 1;
103
4.36M
    return 0;
104
4.36M
}
105
106
808k
int ZEXPORT inflateResetKeep(z_streamp strm) {
107
808k
    struct inflate_state FAR *state;
108
109
808k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
110
808k
    state = (struct inflate_state FAR *)strm->state;
111
808k
    strm->total_in = strm->total_out = state->total = 0;
112
808k
    strm->msg = Z_NULL;
113
808k
    if (state->wrap)        /* to support ill-conceived Java test suite */
114
808k
        strm->adler = state->wrap & 1;
115
808k
    state->mode = HEAD;
116
808k
    state->last = 0;
117
808k
    state->havedict = 0;
118
808k
    state->flags = -1;
119
808k
    state->dmax = 32768U;
120
808k
    state->head = Z_NULL;
121
808k
    state->hold = 0;
122
808k
    state->bits = 0;
123
808k
    state->lencode = state->distcode = state->next = state->codes;
124
808k
    state->sane = 1;
125
808k
    state->back = -1;
126
808k
    Tracev((stderr, "inflate: reset\n"));
127
808k
    return Z_OK;
128
808k
}
129
130
808k
int ZEXPORT inflateReset(z_streamp strm) {
131
808k
    struct inflate_state FAR *state;
132
133
808k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
134
808k
    state = (struct inflate_state FAR *)strm->state;
135
808k
    state->wsize = 0;
136
808k
    state->whave = 0;
137
808k
    state->wnext = 0;
138
808k
    return inflateResetKeep(strm);
139
808k
}
140
141
808k
int ZEXPORT inflateReset2(z_streamp strm, int windowBits) {
142
808k
    int wrap;
143
808k
    struct inflate_state FAR *state;
144
145
    /* get the state */
146
808k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
147
808k
    state = (struct inflate_state FAR *)strm->state;
148
149
    /* extract wrap request from windowBits parameter */
150
808k
    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
808k
    else {
157
808k
        wrap = (windowBits >> 4) + 5;
158
#ifdef GUNZIP
159
        if (windowBits < 48)
160
            windowBits &= 15;
161
#endif
162
808k
    }
163
164
    /* set number of window bits, free window if different */
165
808k
    if (windowBits && (windowBits < 8 || windowBits > 15))
166
0
        return Z_STREAM_ERROR;
167
808k
    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
808k
    state->wrap = wrap;
174
808k
    state->wbits = (unsigned)windowBits;
175
808k
    return inflateReset(strm);
176
808k
}
177
178
int ZEXPORT inflateInit2_(z_streamp strm, int windowBits,
179
808k
                          const char *version, int stream_size) {
180
808k
    int ret;
181
808k
    struct inflate_state FAR *state;
182
183
808k
    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
184
808k
        stream_size != (int)(sizeof(z_stream)))
185
0
        return Z_VERSION_ERROR;
186
808k
    if (strm == Z_NULL) return Z_STREAM_ERROR;
187
808k
    strm->msg = Z_NULL;                 /* in case we return an error */
188
808k
    if (strm->zalloc == (alloc_func)0) {
189
#ifdef Z_SOLO
190
        return Z_STREAM_ERROR;
191
#else
192
808k
        strm->zalloc = zcalloc;
193
808k
        strm->opaque = (voidpf)0;
194
808k
#endif
195
808k
    }
196
808k
    if (strm->zfree == (free_func)0)
197
#ifdef Z_SOLO
198
        return Z_STREAM_ERROR;
199
#else
200
808k
        strm->zfree = zcfree;
201
808k
#endif
202
808k
    state = (struct inflate_state FAR *)
203
808k
            ZALLOC(strm, 1, sizeof(struct inflate_state));
204
808k
    if (state == Z_NULL) return Z_MEM_ERROR;
205
808k
    Tracev((stderr, "inflate: allocated\n"));
206
808k
    strm->state = (struct internal_state FAR *)state;
207
808k
    state->strm = strm;
208
808k
    state->window = Z_NULL;
209
808k
    state->mode = HEAD;     /* to pass state test in inflateReset2() */
210
808k
    ret = inflateReset2(strm, windowBits);
211
808k
    if (ret != Z_OK) {
212
0
        ZFREE(strm, state);
213
0
        strm->state = Z_NULL;
214
0
    }
215
808k
    return ret;
216
808k
}
217
218
int ZEXPORT inflateInit_(z_streamp strm, const char *version,
219
808k
                         int stream_size) {
220
808k
    return inflateInit2_(strm, DEF_WBITS, version, stream_size);
221
808k
}
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
809k
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
809k
#   include "inffixed.h"
286
809k
#endif /* BUILDFIXED */
287
809k
    state->lencode = lenfix;
288
809k
    state->lenbits = 9;
289
809k
    state->distcode = distfix;
290
809k
    state->distbits = 5;
291
809k
}
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
319k
local int updatewindow(z_streamp strm, const Bytef *end, unsigned copy) {
369
319k
    struct inflate_state FAR *state;
370
319k
    unsigned dist;
371
372
319k
    state = (struct inflate_state FAR *)strm->state;
373
374
    /* if it hasn't been done already, allocate space for the window */
375
319k
    if (state->window == Z_NULL) {
376
2.91k
        state->window = (unsigned char FAR *)
377
2.91k
                        ZALLOC(strm, 1U << state->wbits,
378
2.91k
                               sizeof(unsigned char));
379
2.91k
        if (state->window == Z_NULL) return 1;
380
2.91k
    }
381
382
    /* if window not in use yet, initialize */
383
319k
    if (state->wsize == 0) {
384
2.91k
        state->wsize = 1U << state->wbits;
385
2.91k
        state->wnext = 0;
386
2.91k
        state->whave = 0;
387
2.91k
    }
388
389
    /* copy state->wsize or less output bytes into the circular window */
390
319k
    if (copy >= state->wsize) {
391
0
        zmemcpy(state->window, end - state->wsize, state->wsize);
392
0
        state->wnext = 0;
393
0
        state->whave = state->wsize;
394
0
    }
395
319k
    else {
396
319k
        dist = state->wsize - state->wnext;
397
319k
        if (dist > copy) dist = copy;
398
319k
        zmemcpy(state->window + state->wnext, end - copy, dist);
399
319k
        copy -= dist;
400
319k
        if (copy) {
401
39.4k
            zmemcpy(state->window, end - copy, copy);
402
39.4k
            state->wnext = copy;
403
39.4k
            state->whave = state->wsize;
404
39.4k
        }
405
279k
        else {
406
279k
            state->wnext += dist;
407
279k
            if (state->wnext == state->wsize) state->wnext = 0;
408
279k
            if (state->whave < state->wsize) state->whave += dist;
409
279k
        }
410
319k
    }
411
319k
    return 0;
412
319k
}
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
    (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
420
#else
421
1.00M
#  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
    do { \
428
        hbuf[0] = (unsigned char)(word); \
429
        hbuf[1] = (unsigned char)((word) >> 8); \
430
        check = crc32(check, hbuf, 2); \
431
    } while (0)
432
433
#  define CRC4(check, word) \
434
    do { \
435
        hbuf[0] = (unsigned char)(word); \
436
        hbuf[1] = (unsigned char)((word) >> 8); \
437
        hbuf[2] = (unsigned char)((word) >> 16); \
438
        hbuf[3] = (unsigned char)((word) >> 24); \
439
        check = crc32(check, hbuf, 4); \
440
    } while (0)
441
#endif
442
443
/* Load registers with state in inflate() for speed */
444
#define LOAD() \
445
2.29M
    do { \
446
2.29M
        put = strm->next_out; \
447
2.29M
        left = strm->avail_out; \
448
2.29M
        next = strm->next_in; \
449
2.29M
        have = strm->avail_in; \
450
2.29M
        hold = state->hold; \
451
2.29M
        bits = state->bits; \
452
2.29M
    } while (0)
453
454
/* Restore state from registers in inflate() */
455
#define RESTORE() \
456
2.29M
    do { \
457
2.29M
        strm->next_out = put; \
458
2.29M
        strm->avail_out = left; \
459
2.29M
        strm->next_in = next; \
460
2.29M
        strm->avail_in = have; \
461
2.29M
        state->hold = hold; \
462
2.29M
        state->bits = bits; \
463
2.29M
    } while (0)
464
465
/* Clear the input bit accumulator */
466
#define INITBITS() \
467
1.65M
    do { \
468
1.65M
        hold = 0; \
469
1.65M
        bits = 0; \
470
1.65M
    } while (0)
471
472
/* Get a byte of input into the bit accumulator, or return from inflate()
473
   if there is no input available. */
474
#define PULLBYTE() \
475
8.15M
    do { \
476
8.15M
        if (have == 0) goto inf_leave; \
477
8.15M
        have--; \
478
8.14M
        hold += (unsigned long)(*next++) << bits; \
479
8.14M
        bits += 8; \
480
8.14M
    } 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
4.58M
    do { \
486
11.5M
        while (bits < (unsigned)(n)) \
487
6.92M
            PULLBYTE(); \
488
4.58M
    } while (0)
489
490
/* Return the low n bits of the bit accumulator (n < 16) */
491
#define BITS(n) \
492
10.2M
    ((unsigned)hold & ((1U << (n)) - 1))
493
494
/* Remove n bits from the bit accumulator */
495
#define DROPBITS(n) \
496
7.39M
    do { \
497
7.39M
        hold >>= (n); \
498
7.39M
        bits -= (unsigned)(n); \
499
7.39M
    } while (0)
500
501
/* Remove zero to seven bits as needed to go to a byte boundary */
502
#define BYTEBITS() \
503
845k
    do { \
504
845k
        hold >>= bits & 7; \
505
845k
        bits -= bits & 7; \
506
845k
    } 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
1.12M
int ZEXPORT inflate(z_streamp strm, int flush) {
591
1.12M
    struct inflate_state FAR *state;
592
1.12M
    z_const unsigned char FAR *next;    /* next input */
593
1.12M
    unsigned char FAR *put;     /* next output */
594
1.12M
    unsigned have, left;        /* available input and output */
595
1.12M
    unsigned long hold;         /* bit buffer */
596
1.12M
    unsigned bits;              /* bits in bit buffer */
597
1.12M
    unsigned in, out;           /* save starting available input and output */
598
1.12M
    unsigned copy;              /* number of stored or match bytes to copy */
599
1.12M
    unsigned char FAR *from;    /* where to copy match bytes from */
600
1.12M
    code here;                  /* current decoding table entry */
601
1.12M
    code last;                  /* parent table entry */
602
1.12M
    unsigned len;               /* length to copy for repeats, bits to drop */
603
1.12M
    int ret;                    /* return code */
604
#ifdef GUNZIP
605
    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
606
#endif
607
1.12M
    static const unsigned short order[19] = /* permutation of code lengths */
608
1.12M
        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
609
610
1.12M
    if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
611
1.12M
        (strm->next_in == Z_NULL && strm->avail_in != 0))
612
0
        return Z_STREAM_ERROR;
613
614
1.12M
    state = (struct inflate_state FAR *)strm->state;
615
1.12M
    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
616
1.12M
    LOAD();
617
1.12M
    in = have;
618
1.12M
    out = left;
619
1.12M
    ret = Z_OK;
620
1.12M
    for (;;)
621
6.57M
        switch (state->mode) {
622
808k
        case HEAD:
623
808k
            if (state->wrap == 0) {
624
0
                state->mode = TYPEDO;
625
0
                break;
626
0
            }
627
808k
            NEEDBITS(16);
628
#ifdef GUNZIP
629
            if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
630
                if (state->wbits == 0)
631
                    state->wbits = 15;
632
                state->check = crc32(0L, Z_NULL, 0);
633
                CRC2(state->check, hold);
634
                INITBITS();
635
                state->mode = FLAGS;
636
                break;
637
            }
638
            if (state->head != Z_NULL)
639
                state->head->done = -1;
640
            if (!(state->wrap & 1) ||   /* check if zlib header allowed */
641
#else
642
808k
            if (
643
808k
#endif
644
808k
                ((BITS(8) << 8) + (hold >> 8)) % 31) {
645
356
                strm->msg = (char *)"incorrect header check";
646
356
                state->mode = BAD;
647
356
                break;
648
356
            }
649
808k
            if (BITS(4) != Z_DEFLATED) {
650
17
                strm->msg = (char *)"unknown compression method";
651
17
                state->mode = BAD;
652
17
                break;
653
17
            }
654
808k
            DROPBITS(4);
655
808k
            len = BITS(4) + 8;
656
808k
            if (state->wbits == 0)
657
0
                state->wbits = len;
658
808k
            if (len > 15 || len > state->wbits) {
659
6
                strm->msg = (char *)"invalid window size";
660
6
                state->mode = BAD;
661
6
                break;
662
6
            }
663
808k
            state->dmax = 1U << len;
664
808k
            state->flags = 0;               /* indicate zlib header */
665
808k
            Tracev((stderr, "inflate:   zlib header ok\n"));
666
808k
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
667
808k
            state->mode = hold & 0x200 ? DICTID : TYPE;
668
808k
            INITBITS();
669
808k
            break;
670
#ifdef GUNZIP
671
        case FLAGS:
672
            NEEDBITS(16);
673
            state->flags = (int)(hold);
674
            if ((state->flags & 0xff) != Z_DEFLATED) {
675
                strm->msg = (char *)"unknown compression method";
676
                state->mode = BAD;
677
                break;
678
            }
679
            if (state->flags & 0xe000) {
680
                strm->msg = (char *)"unknown header flags set";
681
                state->mode = BAD;
682
                break;
683
            }
684
            if (state->head != Z_NULL)
685
                state->head->text = (int)((hold >> 8) & 1);
686
            if ((state->flags & 0x0200) && (state->wrap & 4))
687
                CRC2(state->check, hold);
688
            INITBITS();
689
            state->mode = TIME;
690
                /* fallthrough */
691
        case TIME:
692
            NEEDBITS(32);
693
            if (state->head != Z_NULL)
694
                state->head->time = hold;
695
            if ((state->flags & 0x0200) && (state->wrap & 4))
696
                CRC4(state->check, hold);
697
            INITBITS();
698
            state->mode = OS;
699
                /* fallthrough */
700
        case OS:
701
            NEEDBITS(16);
702
            if (state->head != Z_NULL) {
703
                state->head->xflags = (int)(hold & 0xff);
704
                state->head->os = (int)(hold >> 8);
705
            }
706
            if ((state->flags & 0x0200) && (state->wrap & 4))
707
                CRC2(state->check, hold);
708
            INITBITS();
709
            state->mode = EXLEN;
710
                /* fallthrough */
711
        case EXLEN:
712
            if (state->flags & 0x0400) {
713
                NEEDBITS(16);
714
                state->length = (unsigned)(hold);
715
                if (state->head != Z_NULL)
716
                    state->head->extra_len = (unsigned)hold;
717
                if ((state->flags & 0x0200) && (state->wrap & 4))
718
                    CRC2(state->check, hold);
719
                INITBITS();
720
            }
721
            else if (state->head != Z_NULL)
722
                state->head->extra = Z_NULL;
723
            state->mode = EXTRA;
724
                /* fallthrough */
725
        case EXTRA:
726
            if (state->flags & 0x0400) {
727
                copy = state->length;
728
                if (copy > have) copy = have;
729
                if (copy) {
730
                    if (state->head != Z_NULL &&
731
                        state->head->extra != Z_NULL &&
732
                        (len = state->head->extra_len - state->length) <
733
                            state->head->extra_max) {
734
                        zmemcpy(state->head->extra + len, next,
735
                                len + copy > state->head->extra_max ?
736
                                state->head->extra_max - len : copy);
737
                    }
738
                    if ((state->flags & 0x0200) && (state->wrap & 4))
739
                        state->check = crc32(state->check, next, copy);
740
                    have -= copy;
741
                    next += copy;
742
                    state->length -= copy;
743
                }
744
                if (state->length) goto inf_leave;
745
            }
746
            state->length = 0;
747
            state->mode = NAME;
748
                /* fallthrough */
749
        case NAME:
750
            if (state->flags & 0x0800) {
751
                if (have == 0) goto inf_leave;
752
                copy = 0;
753
                do {
754
                    len = (unsigned)(next[copy++]);
755
                    if (state->head != Z_NULL &&
756
                            state->head->name != Z_NULL &&
757
                            state->length < state->head->name_max)
758
                        state->head->name[state->length++] = (Bytef)len;
759
                } while (len && copy < have);
760
                if ((state->flags & 0x0200) && (state->wrap & 4))
761
                    state->check = crc32(state->check, next, copy);
762
                have -= copy;
763
                next += copy;
764
                if (len) goto inf_leave;
765
            }
766
            else if (state->head != Z_NULL)
767
                state->head->name = Z_NULL;
768
            state->length = 0;
769
            state->mode = COMMENT;
770
                /* fallthrough */
771
        case COMMENT:
772
            if (state->flags & 0x1000) {
773
                if (have == 0) goto inf_leave;
774
                copy = 0;
775
                do {
776
                    len = (unsigned)(next[copy++]);
777
                    if (state->head != Z_NULL &&
778
                            state->head->comment != Z_NULL &&
779
                            state->length < state->head->comm_max)
780
                        state->head->comment[state->length++] = (Bytef)len;
781
                } while (len && copy < have);
782
                if ((state->flags & 0x0200) && (state->wrap & 4))
783
                    state->check = crc32(state->check, next, copy);
784
                have -= copy;
785
                next += copy;
786
                if (len) goto inf_leave;
787
            }
788
            else if (state->head != Z_NULL)
789
                state->head->comment = Z_NULL;
790
            state->mode = HCRC;
791
                /* fallthrough */
792
        case HCRC:
793
            if (state->flags & 0x0200) {
794
                NEEDBITS(16);
795
                if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
796
                    strm->msg = (char *)"header crc mismatch";
797
                    state->mode = BAD;
798
                    break;
799
                }
800
                INITBITS();
801
            }
802
            if (state->head != Z_NULL) {
803
                state->head->hcrc = (int)((state->flags >> 9) & 1);
804
                state->head->done = 1;
805
            }
806
            strm->adler = state->check = crc32(0L, Z_NULL, 0);
807
            state->mode = TYPE;
808
            break;
809
#endif
810
43
        case DICTID:
811
43
            NEEDBITS(32);
812
43
            strm->adler = state->check = ZSWAP32(hold);
813
43
            INITBITS();
814
43
            state->mode = DICT;
815
                /* fallthrough */
816
43
        case DICT:
817
43
            if (state->havedict == 0) {
818
43
                RESTORE();
819
43
                return Z_NEED_DICT;
820
43
            }
821
0
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
822
0
            state->mode = TYPE;
823
                /* fallthrough */
824
1.70M
        case TYPE:
825
1.70M
            if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
826
                /* fallthrough */
827
1.70M
        case TYPEDO:
828
1.70M
            if (state->last) {
829
804k
                BYTEBITS();
830
804k
                state->mode = CHECK;
831
804k
                break;
832
804k
            }
833
896k
            NEEDBITS(3);
834
896k
            state->last = BITS(1);
835
896k
            DROPBITS(1);
836
896k
            switch (BITS(2)) {
837
40.9k
            case 0:                             /* stored block */
838
40.9k
                Tracev((stderr, "inflate:     stored block%s\n",
839
40.9k
                        state->last ? " (last)" : ""));
840
40.9k
                state->mode = STORED;
841
40.9k
                break;
842
809k
            case 1:                             /* fixed block */
843
809k
                fixedtables(state);
844
809k
                Tracev((stderr, "inflate:     fixed codes block%s\n",
845
809k
                        state->last ? " (last)" : ""));
846
809k
                state->mode = LEN_;             /* decode codes */
847
809k
                if (flush == Z_TREES) {
848
0
                    DROPBITS(2);
849
0
                    goto inf_leave;
850
0
                }
851
809k
                break;
852
809k
            case 2:                             /* dynamic block */
853
45.9k
                Tracev((stderr, "inflate:     dynamic codes block%s\n",
854
45.9k
                        state->last ? " (last)" : ""));
855
45.9k
                state->mode = TABLE;
856
45.9k
                break;
857
24
            case 3:
858
24
                strm->msg = (char *)"invalid block type";
859
24
                state->mode = BAD;
860
896k
            }
861
896k
            DROPBITS(2);
862
896k
            break;
863
40.9k
        case STORED:
864
40.9k
            BYTEBITS();                         /* go to byte boundary */
865
40.9k
            NEEDBITS(32);
866
40.9k
            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
867
174
                strm->msg = (char *)"invalid stored block lengths";
868
174
                state->mode = BAD;
869
174
                break;
870
174
            }
871
40.7k
            state->length = (unsigned)hold & 0xffff;
872
40.7k
            Tracev((stderr, "inflate:       stored length %u\n",
873
40.7k
                    state->length));
874
40.7k
            INITBITS();
875
40.7k
            state->mode = COPY_;
876
40.7k
            if (flush == Z_TREES) goto inf_leave;
877
                /* fallthrough */
878
40.7k
        case COPY_:
879
40.7k
            state->mode = COPY;
880
                /* fallthrough */
881
45.1k
        case COPY:
882
45.1k
            copy = state->length;
883
45.1k
            if (copy) {
884
4.74k
                if (copy > have) copy = have;
885
4.74k
                if (copy > left) copy = left;
886
4.74k
                if (copy == 0) goto inf_leave;
887
3.13k
                zmemcpy(put, next, copy);
888
3.13k
                have -= copy;
889
3.13k
                next += copy;
890
3.13k
                left -= copy;
891
3.13k
                put += copy;
892
3.13k
                state->length -= copy;
893
3.13k
                break;
894
4.74k
            }
895
40.3k
            Tracev((stderr, "inflate:       stored end\n"));
896
40.3k
            state->mode = TYPE;
897
40.3k
            break;
898
45.9k
        case TABLE:
899
45.9k
            NEEDBITS(14);
900
45.9k
            state->nlen = BITS(5) + 257;
901
45.9k
            DROPBITS(5);
902
45.9k
            state->ndist = BITS(5) + 1;
903
45.9k
            DROPBITS(5);
904
45.9k
            state->ncode = BITS(4) + 4;
905
45.9k
            DROPBITS(4);
906
45.9k
#ifndef PKZIP_BUG_WORKAROUND
907
45.9k
            if (state->nlen > 286 || state->ndist > 30) {
908
15
                strm->msg = (char *)"too many length or distance symbols";
909
15
                state->mode = BAD;
910
15
                break;
911
15
            }
912
45.8k
#endif
913
45.8k
            Tracev((stderr, "inflate:       table sizes ok\n"));
914
45.8k
            state->have = 0;
915
45.8k
            state->mode = LENLENS;
916
                /* fallthrough */
917
45.9k
        case LENLENS:
918
902k
            while (state->have < state->ncode) {
919
856k
                NEEDBITS(3);
920
856k
                state->lens[order[state->have++]] = (unsigned short)BITS(3);
921
856k
                DROPBITS(3);
922
856k
            }
923
61.4k
            while (state->have < 19)
924
15.5k
                state->lens[order[state->have++]] = 0;
925
45.8k
            state->next = state->codes;
926
45.8k
            state->lencode = (const code FAR *)(state->next);
927
45.8k
            state->lenbits = 7;
928
45.8k
            ret = inflate_table(CODES, state->lens, 19, &(state->next),
929
45.8k
                                &(state->lenbits), state->work);
930
45.8k
            if (ret) {
931
124
                strm->msg = (char *)"invalid code lengths set";
932
124
                state->mode = BAD;
933
124
                break;
934
124
            }
935
45.7k
            Tracev((stderr, "inflate:       code lengths ok\n"));
936
45.7k
            state->have = 0;
937
45.7k
            state->mode = CODELENS;
938
                /* fallthrough */
939
45.8k
        case CODELENS:
940
963k
            while (state->have < state->nlen + state->ndist) {
941
1.25M
                for (;;) {
942
1.25M
                    here = state->lencode[BITS(state->lenbits)];
943
1.25M
                    if ((unsigned)(here.bits) <= bits) break;
944
334k
                    PULLBYTE();
945
334k
                }
946
917k
                if (here.val < 16) {
947
719k
                    DROPBITS(here.bits);
948
719k
                    state->lens[state->have++] = here.val;
949
719k
                }
950
198k
                else {
951
198k
                    if (here.val == 16) {
952
13.7k
                        NEEDBITS(here.bits + 2);
953
13.7k
                        DROPBITS(here.bits);
954
13.7k
                        if (state->have == 0) {
955
3
                            strm->msg = (char *)"invalid bit length repeat";
956
3
                            state->mode = BAD;
957
3
                            break;
958
3
                        }
959
13.7k
                        len = state->lens[state->have - 1];
960
13.7k
                        copy = 3 + BITS(2);
961
13.7k
                        DROPBITS(2);
962
13.7k
                    }
963
184k
                    else if (here.val == 17) {
964
87.0k
                        NEEDBITS(here.bits + 3);
965
86.9k
                        DROPBITS(here.bits);
966
86.9k
                        len = 0;
967
86.9k
                        copy = 3 + BITS(3);
968
86.9k
                        DROPBITS(3);
969
86.9k
                    }
970
97.9k
                    else {
971
97.9k
                        NEEDBITS(here.bits + 7);
972
97.9k
                        DROPBITS(here.bits);
973
97.9k
                        len = 0;
974
97.9k
                        copy = 11 + BITS(7);
975
97.9k
                        DROPBITS(7);
976
97.9k
                    }
977
198k
                    if (state->have + copy > state->nlen + state->ndist) {
978
125
                        strm->msg = (char *)"invalid bit length repeat";
979
125
                        state->mode = BAD;
980
125
                        break;
981
125
                    }
982
11.9M
                    while (copy--)
983
11.7M
                        state->lens[state->have++] = (unsigned short)len;
984
198k
                }
985
917k
            }
986
987
            /* handle error breaks in while */
988
45.6k
            if (state->mode == BAD) break;
989
990
            /* check for end-of-block code (better have one) */
991
45.5k
            if (state->lens[256] == 0) {
992
28
                strm->msg = (char *)"invalid code -- missing end-of-block";
993
28
                state->mode = BAD;
994
28
                break;
995
28
            }
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
45.5k
            state->next = state->codes;
1001
45.5k
            state->lencode = (const code FAR *)(state->next);
1002
45.5k
            state->lenbits = 9;
1003
45.5k
            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1004
45.5k
                                &(state->lenbits), state->work);
1005
45.5k
            if (ret) {
1006
98
                strm->msg = (char *)"invalid literal/lengths set";
1007
98
                state->mode = BAD;
1008
98
                break;
1009
98
            }
1010
45.4k
            state->distcode = (const code FAR *)(state->next);
1011
45.4k
            state->distbits = 6;
1012
45.4k
            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1013
45.4k
                            &(state->next), &(state->distbits), state->work);
1014
45.4k
            if (ret) {
1015
73
                strm->msg = (char *)"invalid distances set";
1016
73
                state->mode = BAD;
1017
73
                break;
1018
73
            }
1019
45.3k
            Tracev((stderr, "inflate:       codes ok\n"));
1020
45.3k
            state->mode = LEN_;
1021
45.3k
            if (flush == Z_TREES) goto inf_leave;
1022
                /* fallthrough */
1023
854k
        case LEN_:
1024
854k
            state->mode = LEN;
1025
                /* fallthrough */
1026
2.10M
        case LEN:
1027
2.10M
            if (have >= 6 && left >= 258) {
1028
1.17M
                RESTORE();
1029
1.17M
                inflate_fast(strm, out);
1030
1.17M
                LOAD();
1031
1.17M
                if (state->mode == TYPE)
1032
851k
                    state->back = -1;
1033
1.17M
                break;
1034
1.17M
            }
1035
932k
            state->back = 0;
1036
1.53M
            for (;;) {
1037
1.53M
                here = state->lencode[BITS(state->lenbits)];
1038
1.53M
                if ((unsigned)(here.bits) <= bits) break;
1039
602k
                PULLBYTE();
1040
602k
            }
1041
930k
            if (here.op && (here.op & 0xf0) == 0) {
1042
98.1k
                last = here;
1043
115k
                for (;;) {
1044
115k
                    here = state->lencode[last.val +
1045
115k
                            (BITS(last.bits + last.op) >> last.bits)];
1046
115k
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1047
17.8k
                    PULLBYTE();
1048
17.8k
                }
1049
98.0k
                DROPBITS(last.bits);
1050
98.0k
                state->back += last.bits;
1051
98.0k
            }
1052
930k
            DROPBITS(here.bits);
1053
930k
            state->back += here.bits;
1054
930k
            state->length = (unsigned)here.val;
1055
930k
            if ((int)(here.op) == 0) {
1056
251k
                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1057
251k
                        "inflate:         literal '%c'\n" :
1058
251k
                        "inflate:         literal 0x%02x\n", here.val));
1059
251k
                state->mode = LIT;
1060
251k
                break;
1061
251k
            }
1062
679k
            if (here.op & 32) {
1063
1.17k
                Tracevv((stderr, "inflate:         end of block\n"));
1064
1.17k
                state->back = -1;
1065
1.17k
                state->mode = TYPE;
1066
1.17k
                break;
1067
1.17k
            }
1068
677k
            if (here.op & 64) {
1069
16
                strm->msg = (char *)"invalid literal/length code";
1070
16
                state->mode = BAD;
1071
16
                break;
1072
16
            }
1073
677k
            state->extra = (unsigned)(here.op) & 15;
1074
677k
            state->mode = LENEXT;
1075
                /* fallthrough */
1076
678k
        case LENEXT:
1077
678k
            if (state->extra) {
1078
405k
                NEEDBITS(state->extra);
1079
404k
                state->length += BITS(state->extra);
1080
404k
                DROPBITS(state->extra);
1081
404k
                state->back += state->extra;
1082
404k
            }
1083
677k
            Tracevv((stderr, "inflate:         length %u\n", state->length));
1084
677k
            state->was = state->length;
1085
677k
            state->mode = DIST;
1086
                /* fallthrough */
1087
679k
        case DIST:
1088
942k
            for (;;) {
1089
942k
                here = state->distcode[BITS(state->distbits)];
1090
942k
                if ((unsigned)(here.bits) <= bits) break;
1091
263k
                PULLBYTE();
1092
263k
            }
1093
679k
            if ((here.op & 0xf0) == 0) {
1094
56.0k
                last = here;
1095
61.6k
                for (;;) {
1096
61.6k
                    here = state->distcode[last.val +
1097
61.6k
                            (BITS(last.bits + last.op) >> last.bits)];
1098
61.6k
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1099
7.23k
                    PULLBYTE();
1100
7.23k
                }
1101
54.3k
                DROPBITS(last.bits);
1102
54.3k
                state->back += last.bits;
1103
54.3k
            }
1104
677k
            DROPBITS(here.bits);
1105
677k
            state->back += here.bits;
1106
677k
            if (here.op & 64) {
1107
11
                strm->msg = (char *)"invalid distance code";
1108
11
                state->mode = BAD;
1109
11
                break;
1110
11
            }
1111
677k
            state->offset = (unsigned)here.val;
1112
677k
            state->extra = (unsigned)(here.op) & 15;
1113
677k
            state->mode = DISTEXT;
1114
                /* fallthrough */
1115
678k
        case DISTEXT:
1116
678k
            if (state->extra) {
1117
523k
                NEEDBITS(state->extra);
1118
522k
                state->offset += BITS(state->extra);
1119
522k
                DROPBITS(state->extra);
1120
522k
                state->back += state->extra;
1121
522k
            }
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
677k
            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
1130
677k
            state->mode = MATCH;
1131
                /* fallthrough */
1132
1.52M
        case MATCH:
1133
1.52M
            if (left == 0) goto inf_leave;
1134
1.22M
            copy = out - left;
1135
1.22M
            if (state->offset > copy) {         /* copy from window */
1136
314k
                copy = state->offset - copy;
1137
314k
                if (copy > state->whave) {
1138
93
                    if (state->sane) {
1139
93
                        strm->msg = (char *)"invalid distance too far back";
1140
93
                        state->mode = BAD;
1141
93
                        break;
1142
93
                    }
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
93
                }
1157
314k
                if (copy > state->wnext) {
1158
39.0k
                    copy -= state->wnext;
1159
39.0k
                    from = state->window + (state->wsize - copy);
1160
39.0k
                }
1161
275k
                else
1162
275k
                    from = state->window + (state->wnext - copy);
1163
314k
                if (copy > state->length) copy = state->length;
1164
314k
            }
1165
906k
            else {                              /* copy from output */
1166
906k
                from = put - state->offset;
1167
906k
                copy = state->length;
1168
906k
            }
1169
1.22M
            if (copy > left) copy = left;
1170
1.22M
            left -= copy;
1171
1.22M
            state->length -= copy;
1172
81.0M
            do {
1173
81.0M
                *put++ = *from++;
1174
81.0M
            } while (--copy);
1175
1.22M
            if (state->length == 0) state->mode = LEN;
1176
1.22M
            break;
1177
252k
        case LIT:
1178
252k
            if (left == 0) goto inf_leave;
1179
251k
            *put++ = (unsigned char)(state->length);
1180
251k
            left--;
1181
251k
            state->mode = LEN;
1182
251k
            break;
1183
804k
        case CHECK:
1184
804k
            if (state->wrap) {
1185
804k
                NEEDBITS(32);
1186
804k
                out -= left;
1187
804k
                strm->total_out += out;
1188
804k
                state->total += out;
1189
804k
                if ((state->wrap & 4) && out)
1190
686k
                    strm->adler = state->check =
1191
686k
                        UPDATE_CHECK(state->check, put - out, out);
1192
804k
                out = left;
1193
804k
                if ((state->wrap & 4) && (
1194
#ifdef GUNZIP
1195
                     state->flags ? hold :
1196
#endif
1197
804k
                     ZSWAP32(hold)) != state->check) {
1198
325
                    strm->msg = (char *)"incorrect data check";
1199
325
                    state->mode = BAD;
1200
325
                    break;
1201
325
                }
1202
804k
                INITBITS();
1203
804k
                Tracev((stderr, "inflate:   check matches trailer\n"));
1204
804k
            }
1205
#ifdef GUNZIP
1206
            state->mode = LENGTH;
1207
                /* fallthrough */
1208
        case LENGTH:
1209
            if (state->wrap && state->flags) {
1210
                NEEDBITS(32);
1211
                if ((state->wrap & 4) && hold != (state->total & 0xffffffff)) {
1212
                    strm->msg = (char *)"incorrect length check";
1213
                    state->mode = BAD;
1214
                    break;
1215
                }
1216
                INITBITS();
1217
                Tracev((stderr, "inflate:   length matches trailer\n"));
1218
            }
1219
#endif
1220
804k
            state->mode = DONE;
1221
                /* fallthrough */
1222
804k
        case DONE:
1223
804k
            ret = Z_STREAM_END;
1224
804k
            goto inf_leave;
1225
1.86k
        case BAD:
1226
1.86k
            ret = Z_DATA_ERROR;
1227
1.86k
            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
6.57M
        }
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
1.12M
  inf_leave:
1243
1.12M
    RESTORE();
1244
1.12M
    if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
1245
808k
            (state->mode < CHECK || flush != Z_FINISH)))
1246
319k
        if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
1247
0
            state->mode = MEM;
1248
0
            return Z_MEM_ERROR;
1249
0
        }
1250
1.12M
    in -= strm->avail_in;
1251
1.12M
    out -= strm->avail_out;
1252
1.12M
    strm->total_in += in;
1253
1.12M
    strm->total_out += out;
1254
1.12M
    state->total += out;
1255
1.12M
    if ((state->wrap & 4) && out)
1256
319k
        strm->adler = state->check =
1257
319k
            UPDATE_CHECK(state->check, strm->next_out - out, out);
1258
1.12M
    strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
1259
1.12M
                      (state->mode == TYPE ? 128 : 0) +
1260
1.12M
                      (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1261
1.12M
    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1262
318k
        ret = Z_BUF_ERROR;
1263
1.12M
    return ret;
1264
1.12M
}
1265
1266
808k
int ZEXPORT inflateEnd(z_streamp strm) {
1267
808k
    struct inflate_state FAR *state;
1268
808k
    if (inflateStateCheck(strm))
1269
0
        return Z_STREAM_ERROR;
1270
808k
    state = (struct inflate_state FAR *)strm->state;
1271
808k
    if (state->window != Z_NULL) ZFREE(strm, state->window);
1272
808k
    ZFREE(strm, strm->state);
1273
808k
    strm->state = Z_NULL;
1274
808k
    Tracev((stderr, "inflate: end\n"));
1275
808k
    return Z_OK;
1276
808k
}
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
}