Coverage Report

Created: 2024-07-27 06:26

/src/zlib/inflate.c
Line
Count
Source (jump to first uncovered line)
1
/* inflate.c -- zlib decompression
2
 * Copyright (C) 1995-2022 Mark Adler
3
 * For conditions of distribution and use, see copyright notice in zlib.h
4
 */
5
6
/*
7
 * Change history:
8
 *
9
 * 1.2.beta0    24 Nov 2002
10
 * - First version -- complete rewrite of inflate to simplify code, avoid
11
 *   creation of window when not needed, minimize use of window when it is
12
 *   needed, make inffast.c even faster, implement gzip decoding, and to
13
 *   improve code readability and style over the previous zlib inflate code
14
 *
15
 * 1.2.beta1    25 Nov 2002
16
 * - Use pointers for available input and output checking in inffast.c
17
 * - Remove input and output counters in inffast.c
18
 * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
19
 * - Remove unnecessary second byte pull from length extra in inffast.c
20
 * - Unroll direct copy to three copies per loop in inffast.c
21
 *
22
 * 1.2.beta2    4 Dec 2002
23
 * - Change external routine names to reduce potential conflicts
24
 * - Correct filename to inffixed.h for fixed tables in inflate.c
25
 * - Make hbuf[] unsigned char to match parameter type in inflate.c
26
 * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
27
 *   to avoid negation problem on Alphas (64 bit) in inflate.c
28
 *
29
 * 1.2.beta3    22 Dec 2002
30
 * - Add comments on state->bits assertion in inffast.c
31
 * - Add comments on op field in inftrees.h
32
 * - Fix bug in reuse of allocated window after inflateReset()
33
 * - Remove bit fields--back to byte structure for speed
34
 * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
35
 * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
36
 * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
37
 * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
38
 * - Use local copies of stream next and avail values, as well as local bit
39
 *   buffer and bit count in inflate()--for speed when inflate_fast() not used
40
 *
41
 * 1.2.beta4    1 Jan 2003
42
 * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
43
 * - Move a comment on output buffer sizes from inffast.c to inflate.c
44
 * - Add comments in inffast.c to introduce the inflate_fast() routine
45
 * - Rearrange window copies in inflate_fast() for speed and simplification
46
 * - Unroll last copy for window match in inflate_fast()
47
 * - Use local copies of window variables in inflate_fast() for speed
48
 * - Pull out common wnext == 0 case for speed in inflate_fast()
49
 * - Make op and len in inflate_fast() unsigned for consistency
50
 * - Add FAR to lcode and dcode declarations in inflate_fast()
51
 * - Simplified bad distance check in inflate_fast()
52
 * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
53
 *   source file infback.c to provide a call-back interface to inflate for
54
 *   programs like gzip and unzip -- uses window as output buffer to avoid
55
 *   window copying
56
 *
57
 * 1.2.beta5    1 Jan 2003
58
 * - Improved inflateBack() interface to allow the caller to provide initial
59
 *   input in strm.
60
 * - Fixed stored blocks bug in inflateBack()
61
 *
62
 * 1.2.beta6    4 Jan 2003
63
 * - Added comments in inffast.c on effectiveness of POSTINC
64
 * - Typecasting all around to reduce compiler warnings
65
 * - Changed loops from while (1) or do {} while (1) to for (;;), again to
66
 *   make compilers happy
67
 * - Changed type of window in inflateBackInit() to unsigned char *
68
 *
69
 * 1.2.beta7    27 Jan 2003
70
 * - Changed many types to unsigned or unsigned short to avoid warnings
71
 * - Added inflateCopy() function
72
 *
73
 * 1.2.0        9 Mar 2003
74
 * - Changed inflateBack() interface to provide separate opaque descriptors
75
 *   for the in() and out() functions
76
 * - Changed inflateBack() argument and in_func typedef to swap the length
77
 *   and buffer address return values for the input function
78
 * - Check next_in and next_out for Z_NULL on entry to inflate()
79
 *
80
 * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
81
 */
82
83
#include "zutil.h"
84
#include "inftrees.h"
85
#include "inflate.h"
86
#include "inffast.h"
87
88
#ifdef MAKEFIXED
89
#  ifndef BUILDFIXED
90
#    define BUILDFIXED
91
#  endif
92
#endif
93
94
38.2k
local int inflateStateCheck(z_streamp strm) {
95
38.2k
    struct inflate_state FAR *state;
96
38.2k
    if (strm == Z_NULL ||
97
38.2k
        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
98
0
        return 1;
99
38.2k
    state = (struct inflate_state FAR *)strm->state;
100
38.2k
    if (state == Z_NULL || state->strm != strm ||
101
38.2k
        state->mode < HEAD || state->mode > SYNC)
102
0
        return 1;
103
38.2k
    return 0;
104
38.2k
}
105
106
7.48k
int ZEXPORT inflateResetKeep(z_streamp strm) {
107
7.48k
    struct inflate_state FAR *state;
108
109
7.48k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
110
7.48k
    state = (struct inflate_state FAR *)strm->state;
111
7.48k
    strm->total_in = strm->total_out = state->total = 0;
112
7.48k
    strm->msg = Z_NULL;
113
7.48k
    if (state->wrap)        /* to support ill-conceived Java test suite */
114
7.48k
        strm->adler = state->wrap & 1;
115
7.48k
    state->mode = HEAD;
116
7.48k
    state->last = 0;
117
7.48k
    state->havedict = 0;
118
7.48k
    state->flags = -1;
119
7.48k
    state->dmax = 32768U;
120
7.48k
    state->head = Z_NULL;
121
7.48k
    state->hold = 0;
122
7.48k
    state->bits = 0;
123
7.48k
    state->lencode = state->distcode = state->next = state->codes;
124
7.48k
    state->sane = 1;
125
7.48k
    state->back = -1;
126
7.48k
    Tracev((stderr, "inflate: reset\n"));
127
7.48k
    return Z_OK;
128
7.48k
}
129
130
7.48k
int ZEXPORT inflateReset(z_streamp strm) {
131
7.48k
    struct inflate_state FAR *state;
132
133
7.48k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
134
7.48k
    state = (struct inflate_state FAR *)strm->state;
135
7.48k
    state->wsize = 0;
136
7.48k
    state->whave = 0;
137
7.48k
    state->wnext = 0;
138
7.48k
    return inflateResetKeep(strm);
139
7.48k
}
140
141
7.48k
int ZEXPORT inflateReset2(z_streamp strm, int windowBits) {
142
7.48k
    int wrap;
143
7.48k
    struct inflate_state FAR *state;
144
145
    /* get the state */
146
7.48k
    if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
147
7.48k
    state = (struct inflate_state FAR *)strm->state;
148
149
    /* extract wrap request from windowBits parameter */
150
7.48k
    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
7.48k
    else {
157
7.48k
        wrap = (windowBits >> 4) + 5;
158
7.48k
#ifdef GUNZIP
159
7.48k
        if (windowBits < 48)
160
7.48k
            windowBits &= 15;
161
7.48k
#endif
162
7.48k
    }
163
164
    /* set number of window bits, free window if different */
165
7.48k
    if (windowBits && (windowBits < 8 || windowBits > 15))
166
0
        return Z_STREAM_ERROR;
167
7.48k
    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
7.48k
    state->wrap = wrap;
174
7.48k
    state->wbits = (unsigned)windowBits;
175
7.48k
    return inflateReset(strm);
176
7.48k
}
177
178
int ZEXPORT inflateInit2_(z_streamp strm, int windowBits,
179
7.48k
                          const char *version, int stream_size) {
180
7.48k
    int ret;
181
7.48k
    struct inflate_state FAR *state;
182
183
7.48k
    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
184
7.48k
        stream_size != (int)(sizeof(z_stream)))
185
0
        return Z_VERSION_ERROR;
186
7.48k
    if (strm == Z_NULL) return Z_STREAM_ERROR;
187
7.48k
    strm->msg = Z_NULL;                 /* in case we return an error */
188
7.48k
    if (strm->zalloc == (alloc_func)0) {
189
#ifdef Z_SOLO
190
        return Z_STREAM_ERROR;
191
#else
192
7.48k
        strm->zalloc = zcalloc;
193
7.48k
        strm->opaque = (voidpf)0;
194
7.48k
#endif
195
7.48k
    }
196
7.48k
    if (strm->zfree == (free_func)0)
197
#ifdef Z_SOLO
198
        return Z_STREAM_ERROR;
199
#else
200
7.48k
        strm->zfree = zcfree;
201
7.48k
#endif
202
7.48k
    state = (struct inflate_state FAR *)
203
7.48k
            ZALLOC(strm, 1, sizeof(struct inflate_state));
204
7.48k
    if (state == Z_NULL) return Z_MEM_ERROR;
205
7.48k
    Tracev((stderr, "inflate: allocated\n"));
206
7.48k
    strm->state = (struct internal_state FAR *)state;
207
7.48k
    state->strm = strm;
208
7.48k
    state->window = Z_NULL;
209
7.48k
    state->mode = HEAD;     /* to pass state test in inflateReset2() */
210
7.48k
    ret = inflateReset2(strm, windowBits);
211
7.48k
    if (ret != Z_OK) {
212
0
        ZFREE(strm, state);
213
0
        strm->state = Z_NULL;
214
0
    }
215
7.48k
    return ret;
216
7.48k
}
217
218
int ZEXPORT inflateInit_(z_streamp strm, const char *version,
219
7.48k
                         int stream_size) {
220
7.48k
    return inflateInit2_(strm, DEF_WBITS, version, stream_size);
221
7.48k
}
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
3.69M
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
3.69M
#   include "inffixed.h"
286
3.69M
#endif /* BUILDFIXED */
287
3.69M
    state->lencode = lenfix;
288
3.69M
    state->lenbits = 9;
289
3.69M
    state->distcode = distfix;
290
3.69M
    state->distbits = 5;
291
3.69M
}
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
1.22k
local int updatewindow(z_streamp strm, const Bytef *end, unsigned copy) {
369
1.22k
    struct inflate_state FAR *state;
370
1.22k
    unsigned dist;
371
372
1.22k
    state = (struct inflate_state FAR *)strm->state;
373
374
    /* if it hasn't been done already, allocate space for the window */
375
1.22k
    if (state->window == Z_NULL) {
376
614
        state->window = (unsigned char FAR *)
377
614
                        ZALLOC(strm, 1U << state->wbits,
378
614
                               sizeof(unsigned char));
379
614
        if (state->window == Z_NULL) return 1;
380
614
    }
381
382
    /* if window not in use yet, initialize */
383
1.22k
    if (state->wsize == 0) {
384
614
        state->wsize = 1U << state->wbits;
385
614
        state->wnext = 0;
386
614
        state->whave = 0;
387
614
    }
388
389
    /* copy state->wsize or less output bytes into the circular window */
390
1.22k
    if (copy >= state->wsize) {
391
114
        zmemcpy(state->window, end - state->wsize, state->wsize);
392
114
        state->wnext = 0;
393
114
        state->whave = state->wsize;
394
114
    }
395
1.11k
    else {
396
1.11k
        dist = state->wsize - state->wnext;
397
1.11k
        if (dist > copy) dist = copy;
398
1.11k
        zmemcpy(state->window + state->wnext, end - copy, dist);
399
1.11k
        copy -= dist;
400
1.11k
        if (copy) {
401
0
            zmemcpy(state->window, end - copy, copy);
402
0
            state->wnext = copy;
403
0
            state->whave = state->wsize;
404
0
        }
405
1.11k
        else {
406
1.11k
            state->wnext += dist;
407
1.11k
            if (state->wnext == state->wsize) state->wnext = 0;
408
1.11k
            if (state->whave < state->wsize) state->whave += dist;
409
1.11k
        }
410
1.11k
    }
411
1.22k
    return 0;
412
1.22k
}
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
4.97k
    (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
3.71M
    do { \
446
3.71M
        put = strm->next_out; \
447
3.71M
        left = strm->avail_out; \
448
3.71M
        next = strm->next_in; \
449
3.71M
        have = strm->avail_in; \
450
3.71M
        hold = state->hold; \
451
3.71M
        bits = state->bits; \
452
3.71M
    } while (0)
453
454
/* Restore state from registers in inflate() */
455
#define RESTORE() \
456
3.71M
    do { \
457
3.71M
        strm->next_out = put; \
458
3.71M
        strm->avail_out = left; \
459
3.71M
        strm->next_in = next; \
460
3.71M
        strm->avail_in = have; \
461
3.71M
        state->hold = hold; \
462
3.71M
        state->bits = bits; \
463
3.71M
    } while (0)
464
465
/* Clear the input bit accumulator */
466
#define INITBITS() \
467
14.9k
    do { \
468
14.9k
        hold = 0; \
469
14.9k
        bits = 0; \
470
14.9k
    } 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
2.73M
    do { \
476
2.73M
        if (have == 0) goto inf_leave; \
477
2.73M
        have--; \
478
2.73M
        hold += (unsigned long)(*next++) << bits; \
479
2.73M
        bits += 8; \
480
2.73M
    } while (0)
481
482
/* Assure that there are at least n bits in the bit accumulator.  If there is
483
   not enough available input to do that, then return from inflate(). */
484
#define NEEDBITS(n) \
485
4.02M
    do { \
486
6.07M
        while (bits < (unsigned)(n)) \
487
4.02M
            PULLBYTE(); \
488
4.02M
    } while (0)
489
490
/* Return the low n bits of the bit accumulator (n < 16) */
491
#define BITS(n) \
492
10.1M
    ((unsigned)hold & ((1U << (n)) - 1))
493
494
/* Remove n bits from the bit accumulator */
495
#define DROPBITS(n) \
496
9.43M
    do { \
497
9.43M
        hold >>= (n); \
498
9.43M
        bits -= (unsigned)(n); \
499
9.43M
    } while (0)
500
501
/* Remove zero to seven bits as needed to go to a byte boundary */
502
#define BYTEBITS() \
503
9.34k
    do { \
504
9.34k
        hold >>= bits & 7; \
505
9.34k
        bits -= bits & 7; \
506
9.34k
    } 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
8.27k
int ZEXPORT inflate(z_streamp strm, int flush) {
591
8.27k
    struct inflate_state FAR *state;
592
8.27k
    z_const unsigned char FAR *next;    /* next input */
593
8.27k
    unsigned char FAR *put;     /* next output */
594
8.27k
    unsigned have, left;        /* available input and output */
595
8.27k
    unsigned long hold;         /* bit buffer */
596
8.27k
    unsigned bits;              /* bits in bit buffer */
597
8.27k
    unsigned in, out;           /* save starting available input and output */
598
8.27k
    unsigned copy;              /* number of stored or match bytes to copy */
599
8.27k
    unsigned char FAR *from;    /* where to copy match bytes from */
600
8.27k
    code here;                  /* current decoding table entry */
601
8.27k
    code last;                  /* parent table entry */
602
8.27k
    unsigned len;               /* length to copy for repeats, bits to drop */
603
8.27k
    int ret;                    /* return code */
604
8.27k
#ifdef GUNZIP
605
8.27k
    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
606
8.27k
#endif
607
8.27k
    static const unsigned short order[19] = /* permutation of code lengths */
608
8.27k
        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
609
610
8.27k
    if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
611
8.27k
        (strm->next_in == Z_NULL && strm->avail_in != 0))
612
0
        return Z_STREAM_ERROR;
613
614
8.27k
    state = (struct inflate_state FAR *)strm->state;
615
8.27k
    if (state->mode == TYPE) state->mode = TYPEDO;      /* skip check */
616
8.27k
    LOAD();
617
8.27k
    in = have;
618
8.27k
    out = left;
619
8.27k
    ret = Z_OK;
620
8.27k
    for (;;)
621
7.96M
        switch (state->mode) {
622
7.48k
        case HEAD:
623
7.48k
            if (state->wrap == 0) {
624
0
                state->mode = TYPEDO;
625
0
                break;
626
0
            }
627
7.48k
            NEEDBITS(16);
628
7.48k
#ifdef GUNZIP
629
7.48k
            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
7.48k
            if (state->head != Z_NULL)
639
0
                state->head->done = -1;
640
7.48k
            if (!(state->wrap & 1) ||   /* check if zlib header allowed */
641
#else
642
            if (
643
#endif
644
7.48k
                ((BITS(8) << 8) + (hold >> 8)) % 31) {
645
969
                strm->msg = (z_const char *)"incorrect header check";
646
969
                state->mode = BAD;
647
969
                break;
648
969
            }
649
6.51k
            if (BITS(4) != Z_DEFLATED) {
650
156
                strm->msg = (z_const char *)"unknown compression method";
651
156
                state->mode = BAD;
652
156
                break;
653
156
            }
654
6.36k
            DROPBITS(4);
655
6.36k
            len = BITS(4) + 8;
656
6.36k
            if (state->wbits == 0)
657
0
                state->wbits = len;
658
6.36k
            if (len > 15 || len > state->wbits) {
659
0
                strm->msg = (z_const char *)"invalid window size";
660
0
                state->mode = BAD;
661
0
                break;
662
0
            }
663
6.36k
            state->dmax = 1U << len;
664
6.36k
            state->flags = 0;               /* indicate zlib header */
665
6.36k
            Tracev((stderr, "inflate:   zlib header ok\n"));
666
6.36k
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
667
6.36k
            state->mode = hold & 0x200 ? DICTID : TYPE;
668
6.36k
            INITBITS();
669
6.36k
            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 = (z_const char *)"unknown compression method";
676
0
                state->mode = BAD;
677
0
                break;
678
0
            }
679
0
            if (state->flags & 0xe000) {
680
0
                strm->msg = (z_const 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 = (z_const char *)"header crc mismatch";
797
0
                    state->mode = BAD;
798
0
                    break;
799
0
                }
800
0
                INITBITS();
801
0
            }
802
0
            if (state->head != Z_NULL) {
803
0
                state->head->hcrc = (int)((state->flags >> 9) & 1);
804
0
                state->head->done = 1;
805
0
            }
806
0
            strm->adler = state->check = crc32(0L, Z_NULL, 0);
807
0
            state->mode = TYPE;
808
0
            break;
809
0
#endif
810
0
        case DICTID:
811
0
            NEEDBITS(32);
812
0
            strm->adler = state->check = ZSWAP32(hold);
813
0
            INITBITS();
814
0
            state->mode = DICT;
815
                /* fallthrough */
816
0
        case DICT:
817
0
            if (state->havedict == 0) {
818
0
                RESTORE();
819
0
                return Z_NEED_DICT;
820
0
            }
821
0
            strm->adler = state->check = adler32(0L, Z_NULL, 0);
822
0
            state->mode = TYPE;
823
                /* fallthrough */
824
3.71M
        case TYPE:
825
3.71M
            if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
826
                /* fallthrough */
827
3.71M
        case TYPEDO:
828
3.71M
            if (state->last) {
829
3.96k
                BYTEBITS();
830
3.96k
                state->mode = CHECK;
831
3.96k
                break;
832
3.96k
            }
833
3.71M
            NEEDBITS(3);
834
3.71M
            state->last = BITS(1);
835
3.71M
            DROPBITS(1);
836
3.71M
            switch (BITS(2)) {
837
5.36k
            case 0:                             /* stored block */
838
5.36k
                Tracev((stderr, "inflate:     stored block%s\n",
839
5.36k
                        state->last ? " (last)" : ""));
840
5.36k
                state->mode = STORED;
841
5.36k
                break;
842
3.69M
            case 1:                             /* fixed block */
843
3.69M
                fixedtables(state);
844
3.69M
                Tracev((stderr, "inflate:     fixed codes block%s\n",
845
3.69M
                        state->last ? " (last)" : ""));
846
3.69M
                state->mode = LEN_;             /* decode codes */
847
3.69M
                if (flush == Z_TREES) {
848
0
                    DROPBITS(2);
849
0
                    goto inf_leave;
850
0
                }
851
3.69M
                break;
852
3.69M
            case 2:                             /* dynamic block */
853
10.3k
                Tracev((stderr, "inflate:     dynamic codes block%s\n",
854
10.3k
                        state->last ? " (last)" : ""));
855
10.3k
                state->mode = TABLE;
856
10.3k
                break;
857
282
            case 3:
858
282
                strm->msg = (z_const char *)"invalid block type";
859
282
                state->mode = BAD;
860
3.71M
            }
861
3.71M
            DROPBITS(2);
862
3.71M
            break;
863
5.38k
        case STORED:
864
5.38k
            BYTEBITS();                         /* go to byte boundary */
865
5.38k
            NEEDBITS(32);
866
5.33k
            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
867
472
                strm->msg = (z_const char *)"invalid stored block lengths";
868
472
                state->mode = BAD;
869
472
                break;
870
472
            }
871
4.86k
            state->length = (unsigned)hold & 0xffff;
872
4.86k
            Tracev((stderr, "inflate:       stored length %u\n",
873
4.86k
                    state->length));
874
4.86k
            INITBITS();
875
4.86k
            state->mode = COPY_;
876
4.86k
            if (flush == Z_TREES) goto inf_leave;
877
                /* fallthrough */
878
4.86k
        case COPY_:
879
4.86k
            state->mode = COPY;
880
                /* fallthrough */
881
9.34k
        case COPY:
882
9.34k
            copy = state->length;
883
9.34k
            if (copy) {
884
4.60k
                if (copy > have) copy = have;
885
4.60k
                if (copy > left) copy = left;
886
4.60k
                if (copy == 0) goto inf_leave;
887
4.34k
                zmemcpy(put, next, copy);
888
4.34k
                have -= copy;
889
4.34k
                next += copy;
890
4.34k
                left -= copy;
891
4.34k
                put += copy;
892
4.34k
                state->length -= copy;
893
4.34k
                break;
894
4.60k
            }
895
4.73k
            Tracev((stderr, "inflate:       stored end\n"));
896
4.73k
            state->mode = TYPE;
897
4.73k
            break;
898
10.3k
        case TABLE:
899
10.3k
            NEEDBITS(14);
900
10.3k
            state->nlen = BITS(5) + 257;
901
10.3k
            DROPBITS(5);
902
10.3k
            state->ndist = BITS(5) + 1;
903
10.3k
            DROPBITS(5);
904
10.3k
            state->ncode = BITS(4) + 4;
905
10.3k
            DROPBITS(4);
906
10.3k
#ifndef PKZIP_BUG_WORKAROUND
907
10.3k
            if (state->nlen > 286 || state->ndist > 30) {
908
38
                strm->msg = (z_const char *)"too many length or distance symbols";
909
38
                state->mode = BAD;
910
38
                break;
911
38
            }
912
10.2k
#endif
913
10.2k
            Tracev((stderr, "inflate:       table sizes ok\n"));
914
10.2k
            state->have = 0;
915
10.2k
            state->mode = LENLENS;
916
                /* fallthrough */
917
10.3k
        case LENLENS:
918
182k
            while (state->have < state->ncode) {
919
172k
                NEEDBITS(3);
920
172k
                state->lens[order[state->have++]] = (unsigned short)BITS(3);
921
172k
                DROPBITS(3);
922
172k
            }
923
32.8k
            while (state->have < 19)
924
22.6k
                state->lens[order[state->have++]] = 0;
925
10.2k
            state->next = state->codes;
926
10.2k
            state->lencode = (const code FAR *)(state->next);
927
10.2k
            state->lenbits = 7;
928
10.2k
            ret = inflate_table(CODES, state->lens, 19, &(state->next),
929
10.2k
                                &(state->lenbits), state->work);
930
10.2k
            if (ret) {
931
192
                strm->msg = (z_const char *)"invalid code lengths set";
932
192
                state->mode = BAD;
933
192
                break;
934
192
            }
935
10.0k
            Tracev((stderr, "inflate:       code lengths ok\n"));
936
10.0k
            state->have = 0;
937
10.0k
            state->mode = CODELENS;
938
                /* fallthrough */
939
10.1k
        case CODELENS:
940
1.38M
            while (state->have < state->nlen + state->ndist) {
941
1.82M
                for (;;) {
942
1.82M
                    here = state->lencode[BITS(state->lenbits)];
943
1.82M
                    if ((unsigned)(here.bits) <= bits) break;
944
447k
                    PULLBYTE();
945
447k
                }
946
1.37M
                if (here.val < 16) {
947
1.28M
                    DROPBITS(here.bits);
948
1.28M
                    state->lens[state->have++] = here.val;
949
1.28M
                }
950
90.1k
                else {
951
90.1k
                    if (here.val == 16) {
952
54.2k
                        NEEDBITS(here.bits + 2);
953
54.1k
                        DROPBITS(here.bits);
954
54.1k
                        if (state->have == 0) {
955
1
                            strm->msg = (z_const char *)"invalid bit length repeat";
956
1
                            state->mode = BAD;
957
1
                            break;
958
1
                        }
959
54.1k
                        len = state->lens[state->have - 1];
960
54.1k
                        copy = 3 + BITS(2);
961
54.1k
                        DROPBITS(2);
962
54.1k
                    }
963
35.9k
                    else if (here.val == 17) {
964
19.3k
                        NEEDBITS(here.bits + 3);
965
19.3k
                        DROPBITS(here.bits);
966
19.3k
                        len = 0;
967
19.3k
                        copy = 3 + BITS(3);
968
19.3k
                        DROPBITS(3);
969
19.3k
                    }
970
16.5k
                    else {
971
16.5k
                        NEEDBITS(here.bits + 7);
972
16.5k
                        DROPBITS(here.bits);
973
16.5k
                        len = 0;
974
16.5k
                        copy = 11 + BITS(7);
975
16.5k
                        DROPBITS(7);
976
16.5k
                    }
977
90.0k
                    if (state->have + copy > state->nlen + state->ndist) {
978
69
                        strm->msg = (z_const char *)"invalid bit length repeat";
979
69
                        state->mode = BAD;
980
69
                        break;
981
69
                    }
982
1.61M
                    while (copy--)
983
1.52M
                        state->lens[state->have++] = (unsigned short)len;
984
89.9k
                }
985
1.37M
            }
986
987
            /* handle error breaks in while */
988
9.95k
            if (state->mode == BAD) break;
989
990
            /* check for end-of-block code (better have one) */
991
9.88k
            if (state->lens[256] == 0) {
992
23
                strm->msg = (z_const char *)"invalid code -- missing end-of-block";
993
23
                state->mode = BAD;
994
23
                break;
995
23
            }
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
9.86k
            state->next = state->codes;
1001
9.86k
            state->lencode = (const code FAR *)(state->next);
1002
9.86k
            state->lenbits = 9;
1003
9.86k
            ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1004
9.86k
                                &(state->lenbits), state->work);
1005
9.86k
            if (ret) {
1006
81
                strm->msg = (z_const char *)"invalid literal/lengths set";
1007
81
                state->mode = BAD;
1008
81
                break;
1009
81
            }
1010
9.78k
            state->distcode = (const code FAR *)(state->next);
1011
9.78k
            state->distbits = 6;
1012
9.78k
            ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1013
9.78k
                            &(state->next), &(state->distbits), state->work);
1014
9.78k
            if (ret) {
1015
65
                strm->msg = (z_const char *)"invalid distances set";
1016
65
                state->mode = BAD;
1017
65
                break;
1018
65
            }
1019
9.71k
            Tracev((stderr, "inflate:       codes ok\n"));
1020
9.71k
            state->mode = LEN_;
1021
9.71k
            if (flush == Z_TREES) goto inf_leave;
1022
                /* fallthrough */
1023
3.70M
        case LEN_:
1024
3.70M
            state->mode = LEN;
1025
                /* fallthrough */
1026
3.97M
        case LEN:
1027
3.97M
            if (have >= 6 && left >= 258) {
1028
3.70M
                RESTORE();
1029
3.70M
                inflate_fast(strm, out);
1030
3.70M
                LOAD();
1031
3.70M
                if (state->mode == TYPE)
1032
3.70M
                    state->back = -1;
1033
3.70M
                break;
1034
3.70M
            }
1035
275k
            state->back = 0;
1036
502k
            for (;;) {
1037
502k
                here = state->lencode[BITS(state->lenbits)];
1038
502k
                if ((unsigned)(here.bits) <= bits) break;
1039
227k
                PULLBYTE();
1040
227k
            }
1041
275k
            if (here.op && (here.op & 0xf0) == 0) {
1042
13.5k
                last = here;
1043
17.1k
                for (;;) {
1044
17.1k
                    here = state->lencode[last.val +
1045
17.1k
                            (BITS(last.bits + last.op) >> last.bits)];
1046
17.1k
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1047
3.66k
                    PULLBYTE();
1048
3.66k
                }
1049
13.4k
                DROPBITS(last.bits);
1050
13.4k
                state->back += last.bits;
1051
13.4k
            }
1052
275k
            DROPBITS(here.bits);
1053
275k
            state->back += here.bits;
1054
275k
            state->length = (unsigned)here.val;
1055
275k
            if ((int)(here.op) == 0) {
1056
248k
                Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1057
248k
                        "inflate:         literal '%c'\n" :
1058
248k
                        "inflate:         literal 0x%02x\n", here.val));
1059
248k
                state->mode = LIT;
1060
248k
                break;
1061
248k
            }
1062
27.4k
            if (here.op & 32) {
1063
5.55k
                Tracevv((stderr, "inflate:         end of block\n"));
1064
5.55k
                state->back = -1;
1065
5.55k
                state->mode = TYPE;
1066
5.55k
                break;
1067
5.55k
            }
1068
21.9k
            if (here.op & 64) {
1069
5
                strm->msg = (z_const char *)"invalid literal/length code";
1070
5
                state->mode = BAD;
1071
5
                break;
1072
5
            }
1073
21.9k
            state->extra = (unsigned)(here.op) & 15;
1074
21.9k
            state->mode = LENEXT;
1075
                /* fallthrough */
1076
21.9k
        case LENEXT:
1077
21.9k
            if (state->extra) {
1078
5.05k
                NEEDBITS(state->extra);
1079
5.04k
                state->length += BITS(state->extra);
1080
5.04k
                DROPBITS(state->extra);
1081
5.04k
                state->back += state->extra;
1082
5.04k
            }
1083
21.9k
            Tracevv((stderr, "inflate:         length %u\n", state->length));
1084
21.9k
            state->was = state->length;
1085
21.9k
            state->mode = DIST;
1086
                /* fallthrough */
1087
21.9k
        case DIST:
1088
32.6k
            for (;;) {
1089
32.6k
                here = state->distcode[BITS(state->distbits)];
1090
32.6k
                if ((unsigned)(here.bits) <= bits) break;
1091
10.7k
                PULLBYTE();
1092
10.7k
            }
1093
21.9k
            if ((here.op & 0xf0) == 0) {
1094
2.28k
                last = here;
1095
3.39k
                for (;;) {
1096
3.39k
                    here = state->distcode[last.val +
1097
3.39k
                            (BITS(last.bits + last.op) >> last.bits)];
1098
3.39k
                    if ((unsigned)(last.bits + here.bits) <= bits) break;
1099
1.11k
                    PULLBYTE();
1100
1.11k
                }
1101
2.28k
                DROPBITS(last.bits);
1102
2.28k
                state->back += last.bits;
1103
2.28k
            }
1104
21.8k
            DROPBITS(here.bits);
1105
21.8k
            state->back += here.bits;
1106
21.8k
            if (here.op & 64) {
1107
21
                strm->msg = (z_const char *)"invalid distance code";
1108
21
                state->mode = BAD;
1109
21
                break;
1110
21
            }
1111
21.8k
            state->offset = (unsigned)here.val;
1112
21.8k
            state->extra = (unsigned)(here.op) & 15;
1113
21.8k
            state->mode = DISTEXT;
1114
                /* fallthrough */
1115
21.8k
        case DISTEXT:
1116
21.8k
            if (state->extra) {
1117
17.8k
                NEEDBITS(state->extra);
1118
17.7k
                state->offset += BITS(state->extra);
1119
17.7k
                DROPBITS(state->extra);
1120
17.7k
                state->back += state->extra;
1121
17.7k
            }
1122
#ifdef INFLATE_STRICT
1123
            if (state->offset > state->dmax) {
1124
                strm->msg = (z_const char *)"invalid distance too far back";
1125
                state->mode = BAD;
1126
                break;
1127
            }
1128
#endif
1129
21.8k
            Tracevv((stderr, "inflate:         distance %u\n", state->offset));
1130
21.8k
            state->mode = MATCH;
1131
                /* fallthrough */
1132
22.3k
        case MATCH:
1133
22.3k
            if (left == 0) goto inf_leave;
1134
21.8k
            copy = out - left;
1135
21.8k
            if (state->offset > copy) {         /* copy from window */
1136
130
                copy = state->offset - copy;
1137
130
                if (copy > state->whave) {
1138
130
                    if (state->sane) {
1139
130
                        strm->msg = (z_const char *)"invalid distance too far back";
1140
130
                        state->mode = BAD;
1141
130
                        break;
1142
130
                    }
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
130
                }
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
21.7k
            else {                              /* copy from output */
1166
21.7k
                from = put - state->offset;
1167
21.7k
                copy = state->length;
1168
21.7k
            }
1169
21.7k
            if (copy > left) copy = left;
1170
21.7k
            left -= copy;
1171
21.7k
            state->length -= copy;
1172
244k
            do {
1173
244k
                *put++ = *from++;
1174
244k
            } while (--copy);
1175
21.7k
            if (state->length == 0) state->mode = LEN;
1176
21.7k
            break;
1177
248k
        case LIT:
1178
248k
            if (left == 0) goto inf_leave;
1179
248k
            *put++ = (unsigned char)(state->length);
1180
248k
            left--;
1181
248k
            state->mode = LEN;
1182
248k
            break;
1183
3.96k
        case CHECK:
1184
3.96k
            if (state->wrap) {
1185
3.96k
                NEEDBITS(32);
1186
3.95k
                out -= left;
1187
3.95k
                strm->total_out += out;
1188
3.95k
                state->total += out;
1189
3.95k
                if ((state->wrap & 4) && out)
1190
3.86k
                    strm->adler = state->check =
1191
3.86k
                        UPDATE_CHECK(state->check, put - out, out);
1192
3.95k
                out = left;
1193
3.95k
                if ((state->wrap & 4) && (
1194
3.95k
#ifdef GUNZIP
1195
3.95k
                     state->flags ? hold :
1196
3.95k
#endif
1197
3.95k
                     ZSWAP32(hold)) != state->check) {
1198
207
                    strm->msg = (z_const char *)"incorrect data check";
1199
207
                    state->mode = BAD;
1200
207
                    break;
1201
207
                }
1202
3.74k
                INITBITS();
1203
3.74k
                Tracev((stderr, "inflate:   check matches trailer\n"));
1204
3.74k
            }
1205
3.74k
#ifdef GUNZIP
1206
3.74k
            state->mode = LENGTH;
1207
                /* fallthrough */
1208
3.74k
        case LENGTH:
1209
3.74k
            if (state->wrap && state->flags) {
1210
0
                NEEDBITS(32);
1211
0
                if ((state->wrap & 4) && hold != (state->total & 0xffffffff)) {
1212
0
                    strm->msg = (z_const 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
3.74k
#endif
1220
3.74k
            state->mode = DONE;
1221
                /* fallthrough */
1222
3.74k
        case DONE:
1223
3.74k
            ret = Z_STREAM_END;
1224
3.74k
            goto inf_leave;
1225
2.95k
        case BAD:
1226
2.95k
            ret = Z_DATA_ERROR;
1227
2.95k
            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
7.96M
        }
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
8.27k
  inf_leave:
1243
8.27k
    RESTORE();
1244
8.27k
    if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
1245
7.66k
            (state->mode < CHECK || flush != Z_FINISH)))
1246
1.22k
        if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
1247
0
            state->mode = MEM;
1248
0
            return Z_MEM_ERROR;
1249
0
        }
1250
8.27k
    in -= strm->avail_in;
1251
8.27k
    out -= strm->avail_out;
1252
8.27k
    strm->total_in += in;
1253
8.27k
    strm->total_out += out;
1254
8.27k
    state->total += out;
1255
8.27k
    if ((state->wrap & 4) && out)
1256
1.10k
        strm->adler = state->check =
1257
1.10k
            UPDATE_CHECK(state->check, strm->next_out - out, out);
1258
8.27k
    strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
1259
8.27k
                      (state->mode == TYPE ? 128 : 0) +
1260
8.27k
                      (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1261
8.27k
    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1262
786
        ret = Z_BUF_ERROR;
1263
8.27k
    return ret;
1264
8.27k
}
1265
1266
7.48k
int ZEXPORT inflateEnd(z_streamp strm) {
1267
7.48k
    struct inflate_state FAR *state;
1268
7.48k
    if (inflateStateCheck(strm))
1269
0
        return Z_STREAM_ERROR;
1270
7.48k
    state = (struct inflate_state FAR *)strm->state;
1271
7.48k
    if (state->window != Z_NULL) ZFREE(strm, state->window);
1272
7.48k
    ZFREE(strm, strm->state);
1273
7.48k
    strm->state = Z_NULL;
1274
7.48k
    Tracev((stderr, "inflate: end\n"));
1275
7.48k
    return Z_OK;
1276
7.48k
}
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
}