b24e7fce |
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 | 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 | if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || |
38 | stream_size != (int)(sizeof(z_stream))) |
39 | return Z_VERSION_ERROR; |
40 | if (strm == Z_NULL || window == Z_NULL || |
41 | windowBits < 8 || windowBits > 15) |
42 | return Z_STREAM_ERROR; |
43 | strm->msg = Z_NULL; /* in case we return an error */ |
44 | if (strm->zalloc == (alloc_func)0) { |
45 | #ifdef Z_SOLO |
46 | return Z_STREAM_ERROR; |
47 | #else |
48 | strm->zalloc = zcalloc; |
49 | strm->opaque = (voidpf)0; |
50 | #endif |
51 | } |
52 | if (strm->zfree == (free_func)0) |
53 | #ifdef Z_SOLO |
54 | return Z_STREAM_ERROR; |
55 | #else |
56 | strm->zfree = zcfree; |
57 | #endif |
58 | state = (struct inflate_state FAR *)ZALLOC(strm, 1, |
59 | sizeof(struct inflate_state)); |
60 | if (state == Z_NULL) return Z_MEM_ERROR; |
61 | Tracev((stderr, "inflate: allocated\n")); |
62 | strm->state = (struct internal_state FAR *)state; |
63 | state->dmax = 32768U; |
64 | state->wbits = (uInt)windowBits; |
65 | state->wsize = 1U << windowBits; |
66 | state->window = window; |
67 | state->wnext = 0; |
68 | state->whave = 0; |
69 | 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 | 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 | state->lencode = lenfix; |
120 | state->lenbits = 9; |
121 | state->distcode = distfix; |
122 | state->distbits = 5; |
123 | } |
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 | 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 | if (strm == Z_NULL || strm->state == Z_NULL) |
274 | return Z_STREAM_ERROR; |
275 | state = (struct inflate_state FAR *)strm->state; |
276 | |
277 | /* Reset the state */ |
278 | strm->msg = Z_NULL; |
279 | state->mode = TYPE; |
280 | state->last = 0; |
281 | state->whave = 0; |
282 | next = strm->next_in; |
283 | have = next != Z_NULL ? strm->avail_in : 0; |
284 | hold = 0; |
285 | bits = 0; |
286 | put = state->window; |
287 | left = state->wsize; |
288 | |
289 | /* Inflate until end of block marked as last */ |
290 | for (;;) |
291 | switch (state->mode) { |
292 | case TYPE: |
293 | /* determine and dispatch block type */ |
294 | if (state->last) { |
295 | BYTEBITS(); |
296 | state->mode = DONE; |
297 | break; |
298 | } |
299 | NEEDBITS(3); |
300 | state->last = BITS(1); |
301 | DROPBITS(1); |
302 | switch (BITS(2)) { |
303 | case 0: /* stored block */ |
304 | Tracev((stderr, "inflate: stored block%s\n", |
305 | state->last ? " (last)" : "")); |
306 | state->mode = STORED; |
307 | break; |
308 | case 1: /* fixed block */ |
309 | fixedtables(state); |
310 | Tracev((stderr, "inflate: fixed codes block%s\n", |
311 | state->last ? " (last)" : "")); |
312 | state->mode = LEN; /* decode codes */ |
313 | break; |
314 | case 2: /* dynamic block */ |
315 | Tracev((stderr, "inflate: dynamic codes block%s\n", |
316 | state->last ? " (last)" : "")); |
317 | state->mode = TABLE; |
318 | break; |
319 | case 3: |
320 | strm->msg = (char *)"invalid block type"; |
321 | state->mode = BAD; |
322 | } |
323 | DROPBITS(2); |
324 | break; |
325 | |
326 | case STORED: |
327 | /* get and verify stored block length */ |
328 | BYTEBITS(); /* go to byte boundary */ |
329 | NEEDBITS(32); |
330 | if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { |
331 | strm->msg = (char *)"invalid stored block lengths"; |
332 | state->mode = BAD; |
333 | break; |
334 | } |
335 | state->length = (unsigned)hold & 0xffff; |
336 | Tracev((stderr, "inflate: stored length %u\n", |
337 | state->length)); |
338 | INITBITS(); |
339 | |
340 | /* copy stored block from input to output */ |
341 | while (state->length != 0) { |
342 | copy = state->length; |
343 | PULL(); |
344 | ROOM(); |
345 | if (copy > have) copy = have; |
346 | if (copy > left) copy = left; |
347 | zmemcpy(put, next, copy); |
348 | have -= copy; |
349 | next += copy; |
350 | left -= copy; |
351 | put += copy; |
352 | state->length -= copy; |
353 | } |
354 | Tracev((stderr, "inflate: stored end\n")); |
355 | state->mode = TYPE; |
356 | break; |
357 | |
358 | case TABLE: |
359 | /* get dynamic table entries descriptor */ |
360 | NEEDBITS(14); |
361 | state->nlen = BITS(5) + 257; |
362 | DROPBITS(5); |
363 | state->ndist = BITS(5) + 1; |
364 | DROPBITS(5); |
365 | state->ncode = BITS(4) + 4; |
366 | DROPBITS(4); |
367 | #ifndef PKZIP_BUG_WORKAROUND |
368 | if (state->nlen > 286 || state->ndist > 30) { |
369 | strm->msg = (char *)"too many length or distance symbols"; |
370 | state->mode = BAD; |
371 | break; |
372 | } |
373 | #endif |
374 | Tracev((stderr, "inflate: table sizes ok\n")); |
375 | |
376 | /* get code length code lengths (not a typo) */ |
377 | state->have = 0; |
378 | while (state->have < state->ncode) { |
379 | NEEDBITS(3); |
380 | state->lens[order[state->have++]] = (unsigned short)BITS(3); |
381 | DROPBITS(3); |
382 | } |
383 | while (state->have < 19) |
384 | state->lens[order[state->have++]] = 0; |
385 | state->next = state->codes; |
386 | state->lencode = (code const FAR *)(state->next); |
387 | state->lenbits = 7; |
388 | ret = inflate_table(CODES, state->lens, 19, &(state->next), |
389 | &(state->lenbits), state->work); |
390 | if (ret) { |
391 | strm->msg = (char *)"invalid code lengths set"; |
392 | state->mode = BAD; |
393 | break; |
394 | } |
395 | Tracev((stderr, "inflate: code lengths ok\n")); |
396 | |
397 | /* get length and distance code code lengths */ |
398 | state->have = 0; |
399 | while (state->have < state->nlen + state->ndist) { |
400 | for (;;) { |
401 | here = state->lencode[BITS(state->lenbits)]; |
402 | if ((unsigned)(here.bits) <= bits) break; |
403 | PULLBYTE(); |
404 | } |
405 | if (here.val < 16) { |
406 | DROPBITS(here.bits); |
407 | state->lens[state->have++] = here.val; |
408 | } |
409 | else { |
410 | if (here.val == 16) { |
411 | NEEDBITS(here.bits + 2); |
412 | DROPBITS(here.bits); |
413 | if (state->have == 0) { |
414 | strm->msg = (char *)"invalid bit length repeat"; |
415 | state->mode = BAD; |
416 | break; |
417 | } |
418 | len = (unsigned)(state->lens[state->have - 1]); |
419 | copy = 3 + BITS(2); |
420 | DROPBITS(2); |
421 | } |
422 | else if (here.val == 17) { |
423 | NEEDBITS(here.bits + 3); |
424 | DROPBITS(here.bits); |
425 | len = 0; |
426 | copy = 3 + BITS(3); |
427 | DROPBITS(3); |
428 | } |
429 | else { |
430 | NEEDBITS(here.bits + 7); |
431 | DROPBITS(here.bits); |
432 | len = 0; |
433 | copy = 11 + BITS(7); |
434 | DROPBITS(7); |
435 | } |
436 | if (state->have + copy > state->nlen + state->ndist) { |
437 | strm->msg = (char *)"invalid bit length repeat"; |
438 | state->mode = BAD; |
439 | break; |
440 | } |
441 | while (copy--) |
442 | state->lens[state->have++] = (unsigned short)len; |
443 | } |
444 | } |
445 | |
446 | /* handle error breaks in while */ |
447 | if (state->mode == BAD) break; |
448 | |
449 | /* check for end-of-block code (better have one) */ |
450 | if (state->lens[256] == 0) { |
451 | strm->msg = (char *)"invalid code -- missing end-of-block"; |
452 | state->mode = BAD; |
453 | 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 | state->next = state->codes; |
460 | state->lencode = (code const FAR *)(state->next); |
461 | state->lenbits = 9; |
462 | ret = inflate_table(LENS, state->lens, state->nlen, &(state->next), |
463 | &(state->lenbits), state->work); |
464 | if (ret) { |
465 | strm->msg = (char *)"invalid literal/lengths set"; |
466 | state->mode = BAD; |
467 | break; |
468 | } |
469 | state->distcode = (code const FAR *)(state->next); |
470 | state->distbits = 6; |
471 | ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist, |
472 | &(state->next), &(state->distbits), state->work); |
473 | if (ret) { |
474 | strm->msg = (char *)"invalid distances set"; |
475 | state->mode = BAD; |
476 | break; |
477 | } |
478 | Tracev((stderr, "inflate: codes ok\n")); |
479 | state->mode = LEN; |
480 | |
481 | case LEN: |
482 | /* use inflate_fast() if we have enough input and output */ |
483 | if (have >= 6 && left >= 258) { |
484 | RESTORE(); |
485 | if (state->whave < state->wsize) |
486 | state->whave = state->wsize - left; |
487 | inflate_fast(strm, state->wsize); |
488 | LOAD(); |
489 | break; |
490 | } |
491 | |
492 | /* get a literal, length, or end-of-block code */ |
493 | for (;;) { |
494 | here = state->lencode[BITS(state->lenbits)]; |
495 | if ((unsigned)(here.bits) <= bits) break; |
496 | PULLBYTE(); |
497 | } |
498 | if (here.op && (here.op & 0xf0) == 0) { |
499 | last = here; |
500 | for (;;) { |
501 | here = state->lencode[last.val + |
502 | (BITS(last.bits + last.op) >> last.bits)]; |
503 | if ((unsigned)(last.bits + here.bits) <= bits) break; |
504 | PULLBYTE(); |
505 | } |
506 | DROPBITS(last.bits); |
507 | } |
508 | DROPBITS(here.bits); |
509 | state->length = (unsigned)here.val; |
510 | |
511 | /* process literal */ |
512 | 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 | ROOM(); |
517 | *put++ = (unsigned char)(state->length); |
518 | left--; |
519 | state->mode = LEN; |
520 | break; |
521 | } |
522 | |
523 | /* process end of block */ |
524 | if (here.op & 32) { |
525 | Tracevv((stderr, "inflate: end of block\n")); |
526 | state->mode = TYPE; |
527 | break; |
528 | } |
529 | |
530 | /* invalid code */ |
531 | if (here.op & 64) { |
532 | strm->msg = (char *)"invalid literal/length code"; |
533 | state->mode = BAD; |
534 | break; |
535 | } |
536 | |
537 | /* length code -- get extra bits, if any */ |
538 | state->extra = (unsigned)(here.op) & 15; |
539 | if (state->extra != 0) { |
540 | NEEDBITS(state->extra); |
541 | state->length += BITS(state->extra); |
542 | DROPBITS(state->extra); |
543 | } |
544 | Tracevv((stderr, "inflate: length %u\n", state->length)); |
545 | |
546 | /* get distance code */ |
547 | for (;;) { |
548 | here = state->distcode[BITS(state->distbits)]; |
549 | if ((unsigned)(here.bits) <= bits) break; |
550 | PULLBYTE(); |
551 | } |
552 | if ((here.op & 0xf0) == 0) { |
553 | last = here; |
554 | for (;;) { |
555 | here = state->distcode[last.val + |
556 | (BITS(last.bits + last.op) >> last.bits)]; |
557 | if ((unsigned)(last.bits + here.bits) <= bits) break; |
558 | PULLBYTE(); |
559 | } |
560 | DROPBITS(last.bits); |
561 | } |
562 | DROPBITS(here.bits); |
563 | if (here.op & 64) { |
564 | strm->msg = (char *)"invalid distance code"; |
565 | state->mode = BAD; |
566 | break; |
567 | } |
568 | state->offset = (unsigned)here.val; |
569 | |
570 | /* get distance extra bits, if any */ |
571 | state->extra = (unsigned)(here.op) & 15; |
572 | if (state->extra != 0) { |
573 | NEEDBITS(state->extra); |
574 | state->offset += BITS(state->extra); |
575 | DROPBITS(state->extra); |
576 | } |
577 | if (state->offset > state->wsize - (state->whave < state->wsize ? |
578 | left : 0)) { |
579 | strm->msg = (char *)"invalid distance too far back"; |
580 | state->mode = BAD; |
581 | break; |
582 | } |
583 | Tracevv((stderr, "inflate: distance %u\n", state->offset)); |
584 | |
585 | /* copy match from window to output */ |
586 | do { |
587 | ROOM(); |
588 | copy = state->wsize - state->offset; |
589 | if (copy < left) { |
590 | from = put + copy; |
591 | copy = left - copy; |
592 | } |
593 | else { |
594 | from = put - state->offset; |
595 | copy = left; |
596 | } |
597 | if (copy > state->length) copy = state->length; |
598 | state->length -= copy; |
599 | left -= copy; |
600 | do { |
601 | *put++ = *from++; |
602 | } while (--copy); |
603 | } while (state->length != 0); |
604 | break; |
605 | |
606 | case DONE: |
607 | /* inflate stream terminated properly -- write leftover output */ |
608 | ret = Z_STREAM_END; |
609 | if (left < state->wsize) { |
610 | if (out(out_desc, state->window, state->wsize - left)) |
611 | ret = Z_BUF_ERROR; |
612 | } |
613 | goto inf_leave; |
614 | |
615 | case BAD: |
616 | ret = Z_DATA_ERROR; |
617 | goto inf_leave; |
618 | |
619 | default: /* can't happen, but makes compilers happy */ |
620 | ret = Z_STREAM_ERROR; |
621 | goto inf_leave; |
622 | } |
623 | |
624 | /* Return unused input */ |
625 | inf_leave: |
626 | strm->next_in = next; |
627 | strm->avail_in = have; |
628 | return ret; |
629 | } |
630 | |
631 | int ZEXPORT inflateBackEnd(strm) |
632 | z_streamp strm; |
633 | { |
634 | if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0) |
635 | return Z_STREAM_ERROR; |
636 | ZFREE(strm, strm->state); |
637 | strm->state = Z_NULL; |
638 | Tracev((stderr, "inflate: end\n")); |
639 | return Z_OK; |
640 | } |