Line data Source code
1 : /* infback.c -- inflate using a call-back interface
2 : * Copyright (C) 1995-2005 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 0 : 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 0 : strm->zalloc = zcalloc;
46 0 : strm->opaque = (voidpf)0;
47 0 : }
48 0 : if (strm->zfree == (free_func)0) strm->zfree = zcfree;
49 0 : state = (struct inflate_state FAR *)ZALLOC(strm, 1,
50 : sizeof(struct inflate_state));
51 0 : if (state == Z_NULL) return Z_MEM_ERROR;
52 : Tracev((stderr, "inflate: allocated\n"));
53 0 : strm->state = (struct internal_state FAR *)state;
54 0 : state->dmax = 32768U;
55 0 : state->wbits = windowBits;
56 0 : state->wsize = 1U << windowBits;
57 0 : state->window = window;
58 0 : state->write = 0;
59 0 : state->whave = 0;
60 0 : return Z_OK;
61 0 : }
62 :
63 : /*
64 : Return state with length and distance decoding tables and index sizes set to
65 : fixed code decoding. Normally this returns fixed tables from inffixed.h.
66 : If BUILDFIXED is defined, then instead this routine builds the tables the
67 : first time it's called, and returns those tables the first time and
68 : thereafter. This reduces the size of the code by about 2K bytes, in
69 : exchange for a little execution time. However, BUILDFIXED should not be
70 : used for threaded applications, since the rewriting of the tables and virgin
71 : may not be thread-safe.
72 : */
73 0 : local void fixedtables(state)
74 : struct inflate_state FAR *state;
75 : {
76 : #ifdef BUILDFIXED
77 : static int virgin = 1;
78 : static code *lenfix, *distfix;
79 : static code fixed[544];
80 :
81 : /* build fixed huffman tables if first call (may not be thread safe) */
82 : if (virgin) {
83 : unsigned sym, bits;
84 : static code *next;
85 :
86 : /* literal/length table */
87 : sym = 0;
88 : while (sym < 144) state->lens[sym++] = 8;
89 : while (sym < 256) state->lens[sym++] = 9;
90 : while (sym < 280) state->lens[sym++] = 7;
91 : while (sym < 288) state->lens[sym++] = 8;
92 : next = fixed;
93 : lenfix = next;
94 : bits = 9;
95 : inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
96 :
97 : /* distance table */
98 : sym = 0;
99 : while (sym < 32) state->lens[sym++] = 5;
100 : distfix = next;
101 : bits = 5;
102 : inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
103 :
104 : /* do this just once */
105 : virgin = 0;
106 : }
107 : #else /* !BUILDFIXED */
108 : # include "inffixed.h"
109 : #endif /* BUILDFIXED */
110 0 : state->lencode = lenfix;
111 0 : state->lenbits = 9;
112 0 : state->distcode = distfix;
113 0 : state->distbits = 5;
114 0 : }
115 :
116 : /* Macros for inflateBack(): */
117 :
118 : /* Load returned state from inflate_fast() */
119 : #define LOAD() \
120 : do { \
121 : put = strm->next_out; \
122 : left = strm->avail_out; \
123 : next = strm->next_in; \
124 : have = strm->avail_in; \
125 : hold = state->hold; \
126 : bits = state->bits; \
127 : } while (0)
128 :
129 : /* Set state from registers for inflate_fast() */
130 : #define RESTORE() \
131 : do { \
132 : strm->next_out = put; \
133 : strm->avail_out = left; \
134 : strm->next_in = next; \
135 : strm->avail_in = have; \
136 : state->hold = hold; \
137 : state->bits = bits; \
138 : } while (0)
139 :
140 : /* Clear the input bit accumulator */
141 : #define INITBITS() \
142 : do { \
143 : hold = 0; \
144 : bits = 0; \
145 : } while (0)
146 :
147 : /* Assure that some input is available. If input is requested, but denied,
148 : then return a Z_BUF_ERROR from inflateBack(). */
149 : #define PULL() \
150 : do { \
151 : if (have == 0) { \
152 : have = in(in_desc, &next); \
153 : if (have == 0) { \
154 : next = Z_NULL; \
155 : ret = Z_BUF_ERROR; \
156 : goto inf_leave; \
157 : } \
158 : } \
159 : } while (0)
160 :
161 : /* Get a byte of input into the bit accumulator, or return from inflateBack()
162 : with an error if there is no input available. */
163 : #define PULLBYTE() \
164 : do { \
165 : PULL(); \
166 : have--; \
167 : hold += (unsigned long)(*next++) << bits; \
168 : bits += 8; \
169 : } while (0)
170 :
171 : /* Assure that there are at least n bits in the bit accumulator. If there is
172 : not enough available input to do that, then return from inflateBack() with
173 : an error. */
174 : #define NEEDBITS(n) \
175 : do { \
176 : while (bits < (unsigned)(n)) \
177 : PULLBYTE(); \
178 : } while (0)
179 :
180 : /* Return the low n bits of the bit accumulator (n < 16) */
181 : #define BITS(n) \
182 : ((unsigned)hold & ((1U << (n)) - 1))
183 :
184 : /* Remove n bits from the bit accumulator */
185 : #define DROPBITS(n) \
186 : do { \
187 : hold >>= (n); \
188 : bits -= (unsigned)(n); \
189 : } while (0)
190 :
191 : /* Remove zero to seven bits as needed to go to a byte boundary */
192 : #define BYTEBITS() \
193 : do { \
194 : hold >>= bits & 7; \
195 : bits -= bits & 7; \
196 : } while (0)
197 :
198 : /* Assure that some output space is available, by writing out the window
199 : if it's full. If the write fails, return from inflateBack() with a
200 : Z_BUF_ERROR. */
201 : #define ROOM() \
202 : do { \
203 : if (left == 0) { \
204 : put = state->window; \
205 : left = state->wsize; \
206 : state->whave = left; \
207 : if (out(out_desc, put, left)) { \
208 : ret = Z_BUF_ERROR; \
209 : goto inf_leave; \
210 : } \
211 : } \
212 : } while (0)
213 :
214 : /*
215 : strm provides the memory allocation functions and window buffer on input,
216 : and provides information on the unused input on return. For Z_DATA_ERROR
217 : returns, strm will also provide an error message.
218 :
219 : in() and out() are the call-back input and output functions. When
220 : inflateBack() needs more input, it calls in(). When inflateBack() has
221 : filled the window with output, or when it completes with data in the
222 : window, it calls out() to write out the data. The application must not
223 : change the provided input until in() is called again or inflateBack()
224 : returns. The application must not change the window/output buffer until
225 : inflateBack() returns.
226 :
227 : in() and out() are called with a descriptor parameter provided in the
228 : inflateBack() call. This parameter can be a structure that provides the
229 : information required to do the read or write, as well as accumulated
230 : information on the input and output such as totals and check values.
231 :
232 : in() should return zero on failure. out() should return non-zero on
233 : failure. If either in() or out() fails, than inflateBack() returns a
234 : Z_BUF_ERROR. strm->next_in can be checked for Z_NULL to see whether it
235 : was in() or out() that caused in the error. Otherwise, inflateBack()
236 : returns Z_STREAM_END on success, Z_DATA_ERROR for an deflate format
237 : error, or Z_MEM_ERROR if it could not allocate memory for the state.
238 : inflateBack() can also return Z_STREAM_ERROR if the input parameters
239 : are not correct, i.e. strm is Z_NULL or the state was not initialized.
240 : */
241 0 : int ZEXPORT inflateBack(strm, in, in_desc, out, out_desc)
242 : z_streamp strm;
243 : in_func in;
244 : void FAR *in_desc;
245 : out_func out;
246 : void FAR *out_desc;
247 : {
248 : struct inflate_state FAR *state;
249 0 : unsigned char FAR *next; /* next input */
250 : unsigned char FAR *put; /* next output */
251 : unsigned have, left; /* available input and output */
252 : unsigned long hold; /* bit buffer */
253 : unsigned bits; /* bits in bit buffer */
254 : unsigned copy; /* number of stored or match bytes to copy */
255 : unsigned char FAR *from; /* where to copy match bytes from */
256 : code this; /* current decoding table entry */
257 : code last; /* parent table entry */
258 : unsigned len; /* length to copy for repeats, bits to drop */
259 : int ret; /* return code */
260 : static const unsigned short order[19] = /* permutation of code lengths */
261 : {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
262 :
263 : /* Check that the strm exists and that the state was initialized */
264 0 : if (strm == Z_NULL || strm->state == Z_NULL)
265 0 : return Z_STREAM_ERROR;
266 0 : state = (struct inflate_state FAR *)strm->state;
267 :
268 : /* Reset the state */
269 0 : strm->msg = Z_NULL;
270 0 : state->mode = TYPE;
271 0 : state->last = 0;
272 0 : state->whave = 0;
273 0 : next = strm->next_in;
274 0 : have = next != Z_NULL ? strm->avail_in : 0;
275 : hold = 0;
276 : bits = 0;
277 0 : put = state->window;
278 0 : left = state->wsize;
279 :
280 : /* Inflate until end of block marked as last */
281 0 : for (;;)
282 0 : switch (state->mode) {
283 : case TYPE:
284 : /* determine and dispatch block type */
285 0 : if (state->last) {
286 0 : BYTEBITS();
287 0 : state->mode = DONE;
288 0 : break;
289 : }
290 0 : NEEDBITS(3);
291 0 : state->last = BITS(1);
292 0 : DROPBITS(1);
293 0 : switch (BITS(2)) {
294 : case 0: /* stored block */
295 : Tracev((stderr, "inflate: stored block%s\n",
296 : state->last ? " (last)" : ""));
297 0 : state->mode = STORED;
298 0 : break;
299 : case 1: /* fixed block */
300 0 : fixedtables(state);
301 : Tracev((stderr, "inflate: fixed codes block%s\n",
302 : state->last ? " (last)" : ""));
303 0 : state->mode = LEN; /* decode codes */
304 0 : break;
305 : case 2: /* dynamic block */
306 : Tracev((stderr, "inflate: dynamic codes block%s\n",
307 : state->last ? " (last)" : ""));
308 0 : state->mode = TABLE;
309 0 : break;
310 : case 3:
311 : #ifdef SMALL
312 : strm->msg = "error";
313 : #else
314 0 : strm->msg = (char *)"invalid block type";
315 : #endif
316 0 : state->mode = BAD;
317 0 : }
318 0 : DROPBITS(2);
319 0 : break;
320 :
321 : case STORED:
322 : /* get and verify stored block length */
323 0 : BYTEBITS(); /* go to byte boundary */
324 0 : NEEDBITS(32);
325 0 : if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
326 : #ifdef SMALL
327 : strm->msg = "error";
328 : #else
329 0 : strm->msg = (char *)"invalid stored block lengths";
330 : #endif
331 0 : state->mode = BAD;
332 0 : break;
333 : }
334 0 : state->length = (unsigned)hold & 0xffff;
335 : Tracev((stderr, "inflate: stored length %u\n",
336 : state->length));
337 : INITBITS();
338 :
339 : /* copy stored block from input to output */
340 0 : while (state->length != 0) {
341 : copy = state->length;
342 0 : PULL();
343 0 : ROOM();
344 0 : if (copy > have) copy = have;
345 0 : if (copy > left) copy = left;
346 0 : zmemcpy(put, next, copy);
347 0 : have -= copy;
348 0 : next += copy;
349 0 : left -= copy;
350 0 : put += copy;
351 0 : state->length -= copy;
352 : }
353 : Tracev((stderr, "inflate: stored end\n"));
354 0 : state->mode = TYPE;
355 0 : break;
356 :
357 : case TABLE:
358 : /* get dynamic table entries descriptor */
359 0 : NEEDBITS(14);
360 0 : state->nlen = BITS(5) + 257;
361 0 : DROPBITS(5);
362 0 : state->ndist = BITS(5) + 1;
363 0 : DROPBITS(5);
364 0 : state->ncode = BITS(4) + 4;
365 0 : DROPBITS(4);
366 : #ifndef PKZIP_BUG_WORKAROUND
367 0 : if (state->nlen > 286 || state->ndist > 30) {
368 : #ifdef SMALL
369 : strm->msg = "error";
370 : #else
371 0 : strm->msg = (char *)"too many length or distance symbols";
372 : #endif
373 0 : state->mode = BAD;
374 0 : break;
375 : }
376 : #endif
377 : Tracev((stderr, "inflate: table sizes ok\n"));
378 :
379 : /* get code length code lengths (not a typo) */
380 0 : state->have = 0;
381 0 : while (state->have < state->ncode) {
382 0 : NEEDBITS(3);
383 0 : state->lens[order[state->have++]] = (unsigned short)BITS(3);
384 0 : DROPBITS(3);
385 : }
386 0 : while (state->have < 19)
387 0 : state->lens[order[state->have++]] = 0;
388 0 : state->next = state->codes;
389 0 : state->lencode = (code const FAR *)(state->next);
390 0 : state->lenbits = 7;
391 0 : ret = inflate_table(CODES, state->lens, 19, &(state->next),
392 0 : &(state->lenbits), state->work);
393 0 : if (ret) {
394 0 : strm->msg = (char *)"invalid code lengths set";
395 0 : state->mode = BAD;
396 0 : break;
397 : }
398 : Tracev((stderr, "inflate: code lengths ok\n"));
399 :
400 : /* get length and distance code code lengths */
401 0 : state->have = 0;
402 0 : while (state->have < state->nlen + state->ndist) {
403 0 : for (;;) {
404 0 : this = state->lencode[BITS(state->lenbits)];
405 0 : if ((unsigned)(this.bits) <= bits) break;
406 0 : PULLBYTE();
407 : }
408 0 : if (this.val < 16) {
409 0 : NEEDBITS(this.bits);
410 0 : DROPBITS(this.bits);
411 0 : state->lens[state->have++] = this.val;
412 0 : }
413 : else {
414 0 : if (this.val == 16) {
415 0 : NEEDBITS(this.bits + 2);
416 0 : DROPBITS(this.bits);
417 0 : if (state->have == 0) {
418 0 : strm->msg = (char *)"invalid bit length repeat";
419 0 : state->mode = BAD;
420 0 : break;
421 : }
422 0 : len = (unsigned)(state->lens[state->have - 1]);
423 0 : copy = 3 + BITS(2);
424 0 : DROPBITS(2);
425 0 : }
426 0 : else if (this.val == 17) {
427 0 : NEEDBITS(this.bits + 3);
428 0 : DROPBITS(this.bits);
429 : len = 0;
430 0 : copy = 3 + BITS(3);
431 0 : DROPBITS(3);
432 0 : }
433 : else {
434 0 : NEEDBITS(this.bits + 7);
435 0 : DROPBITS(this.bits);
436 : len = 0;
437 0 : copy = 11 + BITS(7);
438 0 : DROPBITS(7);
439 : }
440 0 : if (state->have + copy > state->nlen + state->ndist) {
441 0 : strm->msg = (char *)"invalid bit length repeat";
442 0 : state->mode = BAD;
443 0 : break;
444 : }
445 0 : while (copy--)
446 0 : state->lens[state->have++] = (unsigned short)len;
447 : }
448 : }
449 :
450 : /* handle error breaks in while */
451 0 : if (state->mode == BAD) break;
452 :
453 : /* build code tables */
454 0 : state->next = state->codes;
455 0 : state->lencode = (code const FAR *)(state->next);
456 0 : state->lenbits = 9;
457 0 : ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
458 : &(state->lenbits), state->work);
459 0 : if (ret) {
460 0 : strm->msg = (char *)"invalid literal/lengths set";
461 0 : state->mode = BAD;
462 0 : break;
463 : }
464 0 : state->distcode = (code const FAR *)(state->next);
465 0 : state->distbits = 6;
466 0 : ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
467 : &(state->next), &(state->distbits), state->work);
468 0 : if (ret) {
469 0 : strm->msg = (char *)"invalid distances set";
470 0 : state->mode = BAD;
471 0 : break;
472 : }
473 : Tracev((stderr, "inflate: codes ok\n"));
474 0 : state->mode = LEN;
475 :
476 : case LEN:
477 : #ifndef SLOW
478 : /* use inflate_fast() if we have enough input and output */
479 0 : if (have >= 6 && left >= 258) {
480 0 : RESTORE();
481 0 : if (state->whave < state->wsize)
482 0 : state->whave = state->wsize - left;
483 0 : inflate_fast(strm, state->wsize);
484 0 : LOAD();
485 0 : break;
486 : }
487 : #endif
488 :
489 : /* get a literal, length, or end-of-block code */
490 0 : for (;;) {
491 0 : this = state->lencode[BITS(state->lenbits)];
492 0 : if ((unsigned)(this.bits) <= bits) break;
493 0 : PULLBYTE();
494 : }
495 0 : if (this.op && (this.op & 0xf0) == 0) {
496 : last = this;
497 0 : for (;;) {
498 0 : this = state->lencode[last.val +
499 0 : (BITS(last.bits + last.op) >> last.bits)];
500 0 : if ((unsigned)(last.bits + this.bits) <= bits) break;
501 0 : PULLBYTE();
502 : }
503 0 : DROPBITS(last.bits);
504 0 : }
505 0 : DROPBITS(this.bits);
506 0 : state->length = (unsigned)this.val;
507 :
508 : /* process literal */
509 0 : if (this.op == 0) {
510 : Tracevv((stderr, this.val >= 0x20 && this.val < 0x7f ?
511 : "inflate: literal '%c'\n" :
512 : "inflate: literal 0x%02x\n", this.val));
513 0 : ROOM();
514 0 : *put++ = (unsigned char)(state->length);
515 0 : left--;
516 0 : state->mode = LEN;
517 0 : break;
518 : }
519 :
520 : /* process end of block */
521 0 : if (this.op & 32) {
522 : Tracevv((stderr, "inflate: end of block\n"));
523 0 : state->mode = TYPE;
524 0 : break;
525 : }
526 :
527 : /* invalid code */
528 0 : if (this.op & 64) {
529 0 : strm->msg = (char *)"invalid literal/length code";
530 0 : state->mode = BAD;
531 0 : break;
532 : }
533 :
534 : /* length code -- get extra bits, if any */
535 0 : state->extra = (unsigned)(this.op) & 15;
536 0 : if (state->extra != 0) {
537 0 : NEEDBITS(state->extra);
538 0 : state->length += BITS(state->extra);
539 0 : DROPBITS(state->extra);
540 0 : }
541 : Tracevv((stderr, "inflate: length %u\n", state->length));
542 :
543 : /* get distance code */
544 0 : for (;;) {
545 0 : this = state->distcode[BITS(state->distbits)];
546 0 : if ((unsigned)(this.bits) <= bits) break;
547 0 : PULLBYTE();
548 : }
549 0 : if ((this.op & 0xf0) == 0) {
550 : last = this;
551 0 : for (;;) {
552 0 : this = state->distcode[last.val +
553 0 : (BITS(last.bits + last.op) >> last.bits)];
554 0 : if ((unsigned)(last.bits + this.bits) <= bits) break;
555 0 : PULLBYTE();
556 : }
557 0 : DROPBITS(last.bits);
558 0 : }
559 0 : DROPBITS(this.bits);
560 0 : if (this.op & 64) {
561 0 : strm->msg = (char *)"invalid distance code";
562 0 : state->mode = BAD;
563 0 : break;
564 : }
565 0 : state->offset = (unsigned)this.val;
566 :
567 : /* get distance extra bits, if any */
568 0 : state->extra = (unsigned)(this.op) & 15;
569 0 : if (state->extra != 0) {
570 0 : NEEDBITS(state->extra);
571 0 : state->offset += BITS(state->extra);
572 0 : DROPBITS(state->extra);
573 0 : }
574 0 : if (state->offset > state->wsize - (state->whave < state->wsize ?
575 : left : 0)) {
576 0 : strm->msg = (char *)"invalid distance too far back";
577 0 : state->mode = BAD;
578 0 : break;
579 : }
580 : Tracevv((stderr, "inflate: distance %u\n", state->offset));
581 :
582 : /* copy match from window to output */
583 0 : do {
584 0 : ROOM();
585 0 : copy = state->wsize - state->offset;
586 0 : if (copy < left) {
587 0 : from = put + copy;
588 0 : copy = left - copy;
589 0 : }
590 : else {
591 0 : from = put - state->offset;
592 : copy = left;
593 : }
594 0 : if (copy > state->length) copy = state->length;
595 0 : state->length -= copy;
596 0 : left -= copy;
597 0 : do {
598 0 : *put++ = *from++;
599 0 : } while (--copy);
600 0 : } while (state->length != 0);
601 : break;
602 :
603 : case DONE:
604 : /* inflate stream terminated properly -- write leftover output */
605 : ret = Z_STREAM_END;
606 0 : if (left < state->wsize) {
607 0 : if (out(out_desc, state->window, state->wsize - left))
608 0 : ret = Z_BUF_ERROR;
609 : }
610 : goto inf_leave;
611 :
612 : case BAD:
613 : ret = Z_DATA_ERROR;
614 0 : goto inf_leave;
615 :
616 : default: /* can't happen, but makes compilers happy */
617 : ret = Z_STREAM_ERROR;
618 0 : goto inf_leave;
619 : }
620 :
621 : /* Return unused input */
622 : inf_leave:
623 0 : strm->next_in = next;
624 0 : strm->avail_in = have;
625 0 : return ret;
626 0 : }
627 :
628 0 : int ZEXPORT inflateBackEnd(strm)
629 : z_streamp strm;
630 : {
631 0 : if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
632 0 : return Z_STREAM_ERROR;
633 0 : ZFREE(strm, strm->state);
634 0 : strm->state = Z_NULL;
635 : Tracev((stderr, "inflate: end\n"));
636 0 : return Z_OK;
637 0 : }
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