Line data Source code
1 : /* infback.c -- inflate using a call-back interface
2 : * Copyright (C) 1995-2016 Mark Adler
3 : * For conditions of distribution and use, see copyright notice in zlib.h
4 : */
5 :
6 : /*
7 : This code is largely copied from inflate.c. Normally either infback.o or
8 : inflate.o would be linked into an application--not both. The interface
9 : with inffast.c is retained so that optimized assembler-coded versions of
10 : inflate_fast() can be used with either inflate.c or infback.c.
11 : */
12 :
13 : #include "zutil.h"
14 : #include "inftrees.h"
15 : #include "inflate.h"
16 : #include "inffast.h"
17 :
18 : /* function prototypes */
19 : local void fixedtables OF((struct inflate_state FAR *state));
20 :
21 : /*
22 : strm provides memory allocation functions in zalloc and zfree, or
23 : Z_NULL to use the library memory allocation functions.
24 :
25 : windowBits is in the range 8..15, and window is a user-supplied
26 : window and output buffer that is 2**windowBits bytes.
27 : */
28 0 : int ZEXPORT inflateBackInit_(strm, windowBits, window, version, stream_size)
29 : z_streamp strm;
30 : int windowBits;
31 : unsigned char FAR *window;
32 : const char *version;
33 : int stream_size;
34 : {
35 : struct inflate_state FAR *state;
36 :
37 0 : if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
38 : stream_size != (int)(sizeof(z_stream)))
39 0 : return Z_VERSION_ERROR;
40 0 : if (strm == Z_NULL || window == Z_NULL ||
41 0 : windowBits < 8 || windowBits > 15)
42 0 : return Z_STREAM_ERROR;
43 0 : strm->msg = Z_NULL; /* in case we return an error */
44 0 : if (strm->zalloc == (alloc_func)0) {
45 : #ifdef Z_SOLO
46 : return Z_STREAM_ERROR;
47 : #else
48 0 : strm->zalloc = zcalloc;
49 0 : strm->opaque = (voidpf)0;
50 : #endif
51 : }
52 0 : if (strm->zfree == (free_func)0)
53 : #ifdef Z_SOLO
54 : return Z_STREAM_ERROR;
55 : #else
56 0 : strm->zfree = zcfree;
57 : #endif
58 0 : state = (struct inflate_state FAR *)ZALLOC(strm, 1,
59 : sizeof(struct inflate_state));
60 0 : if (state == Z_NULL) return Z_MEM_ERROR;
61 : Tracev((stderr, "inflate: allocated\n"));
62 0 : strm->state = (struct internal_state FAR *)state;
63 0 : state->dmax = 32768U;
64 0 : state->wbits = (uInt)windowBits;
65 0 : state->wsize = 1U << windowBits;
66 0 : state->window = window;
67 0 : state->wnext = 0;
68 0 : state->whave = 0;
69 0 : return Z_OK;
70 : }
71 :
72 : /*
73 : Return state with length and distance decoding tables and index sizes set to
74 : fixed code decoding. Normally this returns fixed tables from inffixed.h.
75 : If BUILDFIXED is defined, then instead this routine builds the tables the
76 : first time it's called, and returns those tables the first time and
77 : thereafter. This reduces the size of the code by about 2K bytes, in
78 : exchange for a little execution time. However, BUILDFIXED should not be
79 : used for threaded applications, since the rewriting of the tables and virgin
80 : may not be thread-safe.
81 : */
82 0 : local void fixedtables(state)
83 : struct inflate_state FAR *state;
84 : {
85 : #ifdef BUILDFIXED
86 : static int virgin = 1;
87 : static code *lenfix, *distfix;
88 : static code fixed[544];
89 :
90 : /* build fixed huffman tables if first call (may not be thread safe) */
91 : if (virgin) {
92 : unsigned sym, bits;
93 : static code *next;
94 :
95 : /* literal/length table */
96 : sym = 0;
97 : while (sym < 144) state->lens[sym++] = 8;
98 : while (sym < 256) state->lens[sym++] = 9;
99 : while (sym < 280) state->lens[sym++] = 7;
100 : while (sym < 288) state->lens[sym++] = 8;
101 : next = fixed;
102 : lenfix = next;
103 : bits = 9;
104 : inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
105 :
106 : /* distance table */
107 : sym = 0;
108 : while (sym < 32) state->lens[sym++] = 5;
109 : distfix = next;
110 : bits = 5;
111 : inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
112 :
113 : /* do this just once */
114 : virgin = 0;
115 : }
116 : #else /* !BUILDFIXED */
117 : # include "inffixed.h"
118 : #endif /* BUILDFIXED */
119 0 : state->lencode = lenfix;
120 0 : state->lenbits = 9;
121 0 : state->distcode = distfix;
122 0 : state->distbits = 5;
123 0 : }
124 :
125 : /* Macros for inflateBack(): */
126 :
127 : /* Load returned state from inflate_fast() */
128 : #define LOAD() \
129 : do { \
130 : put = strm->next_out; \
131 : left = strm->avail_out; \
132 : next = strm->next_in; \
133 : have = strm->avail_in; \
134 : hold = state->hold; \
135 : bits = state->bits; \
136 : } while (0)
137 :
138 : /* Set state from registers for inflate_fast() */
139 : #define RESTORE() \
140 : do { \
141 : strm->next_out = put; \
142 : strm->avail_out = left; \
143 : strm->next_in = next; \
144 : strm->avail_in = have; \
145 : state->hold = hold; \
146 : state->bits = bits; \
147 : } while (0)
148 :
149 : /* Clear the input bit accumulator */
150 : #define INITBITS() \
151 : do { \
152 : hold = 0; \
153 : bits = 0; \
154 : } while (0)
155 :
156 : /* Assure that some input is available. If input is requested, but denied,
157 : then return a Z_BUF_ERROR from inflateBack(). */
158 : #define PULL() \
159 : do { \
160 : if (have == 0) { \
161 : have = in(in_desc, &next); \
162 : if (have == 0) { \
163 : next = Z_NULL; \
164 : ret = Z_BUF_ERROR; \
165 : goto inf_leave; \
166 : } \
167 : } \
168 : } while (0)
169 :
170 : /* Get a byte of input into the bit accumulator, or return from inflateBack()
171 : with an error if there is no input available. */
172 : #define PULLBYTE() \
173 : do { \
174 : PULL(); \
175 : have--; \
176 : hold += (unsigned long)(*next++) << bits; \
177 : bits += 8; \
178 : } while (0)
179 :
180 : /* Assure that there are at least n bits in the bit accumulator. If there is
181 : not enough available input to do that, then return from inflateBack() with
182 : an error. */
183 : #define NEEDBITS(n) \
184 : do { \
185 : while (bits < (unsigned)(n)) \
186 : PULLBYTE(); \
187 : } while (0)
188 :
189 : /* Return the low n bits of the bit accumulator (n < 16) */
190 : #define BITS(n) \
191 : ((unsigned)hold & ((1U << (n)) - 1))
192 :
193 : /* Remove n bits from the bit accumulator */
194 : #define DROPBITS(n) \
195 : do { \
196 : hold >>= (n); \
197 : bits -= (unsigned)(n); \
198 : } while (0)
199 :
200 : /* Remove zero to seven bits as needed to go to a byte boundary */
201 : #define BYTEBITS() \
202 : do { \
203 : hold >>= bits & 7; \
204 : bits -= bits & 7; \
205 : } while (0)
206 :
207 : /* Assure that some output space is available, by writing out the window
208 : if it's full. If the write fails, return from inflateBack() with a
209 : Z_BUF_ERROR. */
210 : #define ROOM() \
211 : do { \
212 : if (left == 0) { \
213 : put = state->window; \
214 : left = state->wsize; \
215 : state->whave = left; \
216 : if (out(out_desc, put, left)) { \
217 : ret = Z_BUF_ERROR; \
218 : goto inf_leave; \
219 : } \
220 : } \
221 : } while (0)
222 :
223 : /*
224 : strm provides the memory allocation functions and window buffer on input,
225 : and provides information on the unused input on return. For Z_DATA_ERROR
226 : returns, strm will also provide an error message.
227 :
228 : in() and out() are the call-back input and output functions. When
229 : inflateBack() needs more input, it calls in(). When inflateBack() has
230 : filled the window with output, or when it completes with data in the
231 : window, it calls out() to write out the data. The application must not
232 : change the provided input until in() is called again or inflateBack()
233 : returns. The application must not change the window/output buffer until
234 : inflateBack() returns.
235 :
236 : in() and out() are called with a descriptor parameter provided in the
237 : inflateBack() call. This parameter can be a structure that provides the
238 : information required to do the read or write, as well as accumulated
239 : information on the input and output such as totals and check values.
240 :
241 : in() should return zero on failure. out() should return non-zero on
242 : failure. If either in() or out() fails, than inflateBack() returns a
243 : Z_BUF_ERROR. strm->next_in can be checked for Z_NULL to see whether it
244 : was in() or out() that caused in the error. Otherwise, inflateBack()
245 : returns Z_STREAM_END on success, Z_DATA_ERROR for an deflate format
246 : error, or Z_MEM_ERROR if it could not allocate memory for the state.
247 : inflateBack() can also return Z_STREAM_ERROR if the input parameters
248 : are not correct, i.e. strm is Z_NULL or the state was not initialized.
249 : */
250 0 : int ZEXPORT inflateBack(strm, in, in_desc, out, out_desc)
251 : z_streamp strm;
252 : in_func in;
253 : void FAR *in_desc;
254 : out_func out;
255 : void FAR *out_desc;
256 : {
257 : struct inflate_state FAR *state;
258 : z_const unsigned char FAR *next; /* next input */
259 : unsigned char FAR *put; /* next output */
260 : unsigned have, left; /* available input and output */
261 : unsigned long hold; /* bit buffer */
262 : unsigned bits; /* bits in bit buffer */
263 : unsigned copy; /* number of stored or match bytes to copy */
264 : unsigned char FAR *from; /* where to copy match bytes from */
265 : code here; /* current decoding table entry */
266 : code last; /* parent table entry */
267 : unsigned len; /* length to copy for repeats, bits to drop */
268 : int ret; /* return code */
269 : static const unsigned short order[19] = /* permutation of code lengths */
270 : {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
271 :
272 : /* Check that the strm exists and that the state was initialized */
273 0 : if (strm == Z_NULL || strm->state == Z_NULL)
274 0 : return Z_STREAM_ERROR;
275 0 : state = (struct inflate_state FAR *)strm->state;
276 :
277 : /* Reset the state */
278 0 : strm->msg = Z_NULL;
279 0 : state->mode = TYPE;
280 0 : state->last = 0;
281 0 : state->whave = 0;
282 0 : next = strm->next_in;
283 0 : have = next != Z_NULL ? strm->avail_in : 0;
284 0 : hold = 0;
285 0 : bits = 0;
286 0 : put = state->window;
287 0 : left = state->wsize;
288 :
289 : /* Inflate until end of block marked as last */
290 : for (;;)
291 0 : switch (state->mode) {
292 : case TYPE:
293 : /* determine and dispatch block type */
294 0 : if (state->last) {
295 0 : BYTEBITS();
296 0 : state->mode = DONE;
297 0 : break;
298 : }
299 0 : NEEDBITS(3);
300 0 : state->last = BITS(1);
301 0 : DROPBITS(1);
302 0 : switch (BITS(2)) {
303 : case 0: /* stored block */
304 : Tracev((stderr, "inflate: stored block%s\n",
305 : state->last ? " (last)" : ""));
306 0 : state->mode = STORED;
307 0 : break;
308 : case 1: /* fixed block */
309 0 : fixedtables(state);
310 : Tracev((stderr, "inflate: fixed codes block%s\n",
311 : state->last ? " (last)" : ""));
312 0 : state->mode = LEN; /* decode codes */
313 0 : break;
314 : case 2: /* dynamic block */
315 : Tracev((stderr, "inflate: dynamic codes block%s\n",
316 : state->last ? " (last)" : ""));
317 0 : state->mode = TABLE;
318 0 : break;
319 : case 3:
320 0 : strm->msg = (char *)"invalid block type";
321 0 : state->mode = BAD;
322 : }
323 0 : DROPBITS(2);
324 0 : break;
325 :
326 : case STORED:
327 : /* get and verify stored block length */
328 0 : BYTEBITS(); /* go to byte boundary */
329 0 : NEEDBITS(32);
330 0 : if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
331 0 : strm->msg = (char *)"invalid stored block lengths";
332 0 : state->mode = BAD;
333 0 : break;
334 : }
335 0 : state->length = (unsigned)hold & 0xffff;
336 : Tracev((stderr, "inflate: stored length %u\n",
337 : state->length));
338 0 : INITBITS();
339 :
340 : /* copy stored block from input to output */
341 0 : while (state->length != 0) {
342 0 : copy = state->length;
343 0 : PULL();
344 0 : ROOM();
345 0 : if (copy > have) copy = have;
346 0 : if (copy > left) copy = left;
347 0 : zmemcpy(put, next, copy);
348 0 : have -= copy;
349 0 : next += copy;
350 0 : left -= copy;
351 0 : put += copy;
352 0 : state->length -= copy;
353 : }
354 : Tracev((stderr, "inflate: stored end\n"));
355 0 : state->mode = TYPE;
356 0 : break;
357 :
358 : case TABLE:
359 : /* get dynamic table entries descriptor */
360 0 : NEEDBITS(14);
361 0 : state->nlen = BITS(5) + 257;
362 0 : DROPBITS(5);
363 0 : state->ndist = BITS(5) + 1;
364 0 : DROPBITS(5);
365 0 : state->ncode = BITS(4) + 4;
366 0 : DROPBITS(4);
367 : #ifndef PKZIP_BUG_WORKAROUND
368 0 : if (state->nlen > 286 || state->ndist > 30) {
369 0 : strm->msg = (char *)"too many length or distance symbols";
370 0 : state->mode = BAD;
371 0 : break;
372 : }
373 : #endif
374 : Tracev((stderr, "inflate: table sizes ok\n"));
375 :
376 : /* get code length code lengths (not a typo) */
377 0 : state->have = 0;
378 0 : while (state->have < state->ncode) {
379 0 : NEEDBITS(3);
380 0 : state->lens[order[state->have++]] = (unsigned short)BITS(3);
381 0 : DROPBITS(3);
382 : }
383 0 : while (state->have < 19)
384 0 : state->lens[order[state->have++]] = 0;
385 0 : state->next = state->codes;
386 0 : state->lencode = (code const FAR *)(state->next);
387 0 : state->lenbits = 7;
388 0 : ret = inflate_table(CODES, state->lens, 19, &(state->next),
389 0 : &(state->lenbits), state->work);
390 0 : if (ret) {
391 0 : strm->msg = (char *)"invalid code lengths set";
392 0 : state->mode = BAD;
393 0 : break;
394 : }
395 : Tracev((stderr, "inflate: code lengths ok\n"));
396 :
397 : /* get length and distance code code lengths */
398 0 : state->have = 0;
399 0 : while (state->have < state->nlen + state->ndist) {
400 : for (;;) {
401 0 : here = state->lencode[BITS(state->lenbits)];
402 0 : if ((unsigned)(here.bits) <= bits) break;
403 0 : PULLBYTE();
404 : }
405 0 : if (here.val < 16) {
406 0 : DROPBITS(here.bits);
407 0 : state->lens[state->have++] = here.val;
408 : }
409 : else {
410 0 : if (here.val == 16) {
411 0 : NEEDBITS(here.bits + 2);
412 0 : DROPBITS(here.bits);
413 0 : if (state->have == 0) {
414 0 : strm->msg = (char *)"invalid bit length repeat";
415 0 : state->mode = BAD;
416 0 : break;
417 : }
418 0 : len = (unsigned)(state->lens[state->have - 1]);
419 0 : copy = 3 + BITS(2);
420 0 : DROPBITS(2);
421 : }
422 0 : else if (here.val == 17) {
423 0 : NEEDBITS(here.bits + 3);
424 0 : DROPBITS(here.bits);
425 0 : len = 0;
426 0 : copy = 3 + BITS(3);
427 0 : DROPBITS(3);
428 : }
429 : else {
430 0 : NEEDBITS(here.bits + 7);
431 0 : DROPBITS(here.bits);
432 0 : len = 0;
433 0 : copy = 11 + BITS(7);
434 0 : DROPBITS(7);
435 : }
436 0 : if (state->have + copy > state->nlen + state->ndist) {
437 0 : strm->msg = (char *)"invalid bit length repeat";
438 0 : state->mode = BAD;
439 0 : break;
440 : }
441 0 : while (copy--)
442 0 : state->lens[state->have++] = (unsigned short)len;
443 : }
444 : }
445 :
446 : /* handle error breaks in while */
447 0 : if (state->mode == BAD) break;
448 :
449 : /* check for end-of-block code (better have one) */
450 0 : if (state->lens[256] == 0) {
451 0 : strm->msg = (char *)"invalid code -- missing end-of-block";
452 0 : state->mode = BAD;
453 0 : break;
454 : }
455 :
456 : /* build code tables -- note: do not change the lenbits or distbits
457 : values here (9 and 6) without reading the comments in inftrees.h
458 : concerning the ENOUGH constants, which depend on those values */
459 0 : state->next = state->codes;
460 0 : state->lencode = (code const FAR *)(state->next);
461 0 : state->lenbits = 9;
462 0 : ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
463 0 : &(state->lenbits), state->work);
464 0 : if (ret) {
465 0 : strm->msg = (char *)"invalid literal/lengths set";
466 0 : state->mode = BAD;
467 0 : break;
468 : }
469 0 : state->distcode = (code const FAR *)(state->next);
470 0 : state->distbits = 6;
471 0 : ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
472 0 : &(state->next), &(state->distbits), state->work);
473 0 : if (ret) {
474 0 : strm->msg = (char *)"invalid distances set";
475 0 : state->mode = BAD;
476 0 : break;
477 : }
478 : Tracev((stderr, "inflate: codes ok\n"));
479 0 : state->mode = LEN;
480 :
481 : case LEN:
482 : /* use inflate_fast() if we have enough input and output */
483 0 : if (have >= 6 && left >= 258) {
484 0 : RESTORE();
485 0 : if (state->whave < state->wsize)
486 0 : state->whave = state->wsize - left;
487 0 : inflate_fast(strm, state->wsize);
488 0 : LOAD();
489 0 : break;
490 : }
491 :
492 : /* get a literal, length, or end-of-block code */
493 : for (;;) {
494 0 : here = state->lencode[BITS(state->lenbits)];
495 0 : if ((unsigned)(here.bits) <= bits) break;
496 0 : PULLBYTE();
497 : }
498 0 : if (here.op && (here.op & 0xf0) == 0) {
499 0 : last = here;
500 : for (;;) {
501 0 : here = state->lencode[last.val +
502 0 : (BITS(last.bits + last.op) >> last.bits)];
503 0 : if ((unsigned)(last.bits + here.bits) <= bits) break;
504 0 : PULLBYTE();
505 : }
506 0 : DROPBITS(last.bits);
507 : }
508 0 : DROPBITS(here.bits);
509 0 : state->length = (unsigned)here.val;
510 :
511 : /* process literal */
512 0 : if (here.op == 0) {
513 : Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
514 : "inflate: literal '%c'\n" :
515 : "inflate: literal 0x%02x\n", here.val));
516 0 : ROOM();
517 0 : *put++ = (unsigned char)(state->length);
518 0 : left--;
519 0 : state->mode = LEN;
520 0 : break;
521 : }
522 :
523 : /* process end of block */
524 0 : if (here.op & 32) {
525 : Tracevv((stderr, "inflate: end of block\n"));
526 0 : state->mode = TYPE;
527 0 : break;
528 : }
529 :
530 : /* invalid code */
531 0 : if (here.op & 64) {
532 0 : strm->msg = (char *)"invalid literal/length code";
533 0 : state->mode = BAD;
534 0 : break;
535 : }
536 :
537 : /* length code -- get extra bits, if any */
538 0 : state->extra = (unsigned)(here.op) & 15;
539 0 : if (state->extra != 0) {
540 0 : NEEDBITS(state->extra);
541 0 : state->length += BITS(state->extra);
542 0 : DROPBITS(state->extra);
543 : }
544 : Tracevv((stderr, "inflate: length %u\n", state->length));
545 :
546 : /* get distance code */
547 : for (;;) {
548 0 : here = state->distcode[BITS(state->distbits)];
549 0 : if ((unsigned)(here.bits) <= bits) break;
550 0 : PULLBYTE();
551 : }
552 0 : if ((here.op & 0xf0) == 0) {
553 0 : last = here;
554 : for (;;) {
555 0 : here = state->distcode[last.val +
556 0 : (BITS(last.bits + last.op) >> last.bits)];
557 0 : if ((unsigned)(last.bits + here.bits) <= bits) break;
558 0 : PULLBYTE();
559 : }
560 0 : DROPBITS(last.bits);
561 : }
562 0 : DROPBITS(here.bits);
563 0 : if (here.op & 64) {
564 0 : strm->msg = (char *)"invalid distance code";
565 0 : state->mode = BAD;
566 0 : break;
567 : }
568 0 : state->offset = (unsigned)here.val;
569 :
570 : /* get distance extra bits, if any */
571 0 : state->extra = (unsigned)(here.op) & 15;
572 0 : if (state->extra != 0) {
573 0 : NEEDBITS(state->extra);
574 0 : state->offset += BITS(state->extra);
575 0 : DROPBITS(state->extra);
576 : }
577 0 : if (state->offset > state->wsize - (state->whave < state->wsize ?
578 0 : left : 0)) {
579 0 : strm->msg = (char *)"invalid distance too far back";
580 0 : state->mode = BAD;
581 0 : break;
582 : }
583 : Tracevv((stderr, "inflate: distance %u\n", state->offset));
584 :
585 : /* copy match from window to output */
586 : do {
587 0 : ROOM();
588 0 : copy = state->wsize - state->offset;
589 0 : if (copy < left) {
590 0 : from = put + copy;
591 0 : copy = left - copy;
592 : }
593 : else {
594 0 : from = put - state->offset;
595 0 : copy = left;
596 : }
597 0 : if (copy > state->length) copy = state->length;
598 0 : state->length -= copy;
599 0 : left -= copy;
600 : do {
601 0 : *put++ = *from++;
602 0 : } while (--copy);
603 0 : } while (state->length != 0);
604 0 : break;
605 :
606 : case DONE:
607 : /* inflate stream terminated properly -- write leftover output */
608 0 : ret = Z_STREAM_END;
609 0 : if (left < state->wsize) {
610 0 : if (out(out_desc, state->window, state->wsize - left))
611 0 : ret = Z_BUF_ERROR;
612 : }
613 0 : goto inf_leave;
614 :
615 : case BAD:
616 0 : ret = Z_DATA_ERROR;
617 0 : goto inf_leave;
618 :
619 : default: /* can't happen, but makes compilers happy */
620 0 : ret = Z_STREAM_ERROR;
621 0 : goto inf_leave;
622 : }
623 :
624 : /* Return unused input */
625 : inf_leave:
626 0 : strm->next_in = next;
627 0 : strm->avail_in = have;
628 0 : return ret;
629 : }
630 :
631 0 : int ZEXPORT inflateBackEnd(strm)
632 : z_streamp strm;
633 : {
634 0 : if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
635 0 : return Z_STREAM_ERROR;
636 0 : ZFREE(strm, strm->state);
637 0 : strm->state = Z_NULL;
638 : Tracev((stderr, "inflate: end\n"));
639 0 : return Z_OK;
640 : }
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