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4f3865fb RP |
1 | /* inflate.c -- zlib decompression |
2 | * Copyright (C) 1995-2005 Mark Adler | |
3 | * For conditions of distribution and use, see copyright notice in zlib.h | |
4 | * | |
5 | * Based on zlib 1.2.3 but modified for the Linux Kernel by | |
6 | * Richard Purdie <richard@openedhand.com> | |
7 | * | |
8 | * Changes mainly for static instead of dynamic memory allocation | |
9 | * | |
1da177e4 LT |
10 | */ |
11 | ||
1da177e4 | 12 | #include <linux/zutil.h> |
4f3865fb RP |
13 | #include "inftrees.h" |
14 | #include "inflate.h" | |
15 | #include "inffast.h" | |
1da177e4 LT |
16 | #include "infutil.h" |
17 | ||
18 | int zlib_inflate_workspacesize(void) | |
19 | { | |
4f3865fb | 20 | return sizeof(struct inflate_workspace); |
1da177e4 LT |
21 | } |
22 | ||
4f3865fb RP |
23 | int zlib_inflateReset(z_streamp strm) |
24 | { | |
25 | struct inflate_state *state; | |
26 | ||
27 | if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR; | |
28 | state = (struct inflate_state *)strm->state; | |
29 | strm->total_in = strm->total_out = state->total = 0; | |
30 | strm->msg = NULL; | |
31 | strm->adler = 1; /* to support ill-conceived Java test suite */ | |
32 | state->mode = HEAD; | |
33 | state->last = 0; | |
34 | state->havedict = 0; | |
35 | state->dmax = 32768U; | |
36 | state->hold = 0; | |
37 | state->bits = 0; | |
38 | state->lencode = state->distcode = state->next = state->codes; | |
1da177e4 | 39 | |
4f3865fb RP |
40 | /* Initialise Window */ |
41 | state->wsize = 1U << state->wbits; | |
42 | state->write = 0; | |
43 | state->whave = 0; | |
44 | ||
45 | return Z_OK; | |
46 | } | |
47 | ||
4f3865fb RP |
48 | int zlib_inflateInit2(z_streamp strm, int windowBits) |
49 | { | |
50 | struct inflate_state *state; | |
51 | ||
52 | if (strm == NULL) return Z_STREAM_ERROR; | |
53 | strm->msg = NULL; /* in case we return an error */ | |
54 | ||
55 | state = &WS(strm)->inflate_state; | |
56 | strm->state = (struct internal_state *)state; | |
57 | ||
58 | if (windowBits < 0) { | |
59 | state->wrap = 0; | |
60 | windowBits = -windowBits; | |
61 | } | |
62 | else { | |
63 | state->wrap = (windowBits >> 4) + 1; | |
64 | } | |
65 | if (windowBits < 8 || windowBits > 15) { | |
66 | return Z_STREAM_ERROR; | |
67 | } | |
68 | state->wbits = (unsigned)windowBits; | |
69 | state->window = &WS(strm)->working_window[0]; | |
1da177e4 | 70 | |
4f3865fb RP |
71 | return zlib_inflateReset(strm); |
72 | } | |
1da177e4 | 73 | |
4f3865fb RP |
74 | /* |
75 | Return state with length and distance decoding tables and index sizes set to | |
76 | fixed code decoding. This returns fixed tables from inffixed.h. | |
77 | */ | |
78 | static void zlib_fixedtables(struct inflate_state *state) | |
1da177e4 | 79 | { |
4f3865fb RP |
80 | # include "inffixed.h" |
81 | state->lencode = lenfix; | |
82 | state->lenbits = 9; | |
83 | state->distcode = distfix; | |
84 | state->distbits = 5; | |
1da177e4 LT |
85 | } |
86 | ||
87 | ||
4f3865fb RP |
88 | /* |
89 | Update the window with the last wsize (normally 32K) bytes written before | |
90 | returning. This is only called when a window is already in use, or when | |
91 | output has been written during this inflate call, but the end of the deflate | |
92 | stream has not been reached yet. It is also called to window dictionary data | |
93 | when a dictionary is loaded. | |
94 | ||
95 | Providing output buffers larger than 32K to inflate() should provide a speed | |
96 | advantage, since only the last 32K of output is copied to the sliding window | |
97 | upon return from inflate(), and since all distances after the first 32K of | |
98 | output will fall in the output data, making match copies simpler and faster. | |
99 | The advantage may be dependent on the size of the processor's data caches. | |
100 | */ | |
101 | static void zlib_updatewindow(z_streamp strm, unsigned out) | |
1da177e4 | 102 | { |
4f3865fb RP |
103 | struct inflate_state *state; |
104 | unsigned copy, dist; | |
105 | ||
106 | state = (struct inflate_state *)strm->state; | |
107 | ||
108 | /* copy state->wsize or less output bytes into the circular window */ | |
109 | copy = out - strm->avail_out; | |
110 | if (copy >= state->wsize) { | |
111 | memcpy(state->window, strm->next_out - state->wsize, state->wsize); | |
112 | state->write = 0; | |
113 | state->whave = state->wsize; | |
114 | } | |
115 | else { | |
116 | dist = state->wsize - state->write; | |
117 | if (dist > copy) dist = copy; | |
118 | memcpy(state->window + state->write, strm->next_out - copy, dist); | |
119 | copy -= dist; | |
120 | if (copy) { | |
121 | memcpy(state->window, strm->next_out - copy, copy); | |
122 | state->write = copy; | |
123 | state->whave = state->wsize; | |
124 | } | |
125 | else { | |
126 | state->write += dist; | |
127 | if (state->write == state->wsize) state->write = 0; | |
128 | if (state->whave < state->wsize) state->whave += dist; | |
129 | } | |
130 | } | |
1da177e4 LT |
131 | } |
132 | ||
133 | ||
134 | /* | |
135 | * At the end of a Deflate-compressed PPP packet, we expect to have seen | |
136 | * a `stored' block type value but not the (zero) length bytes. | |
137 | */ | |
4f3865fb RP |
138 | /* |
139 | Returns true if inflate is currently at the end of a block generated by | |
140 | Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP | |
141 | implementation to provide an additional safety check. PPP uses | |
142 | Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored | |
143 | block. When decompressing, PPP checks that at the end of input packet, | |
144 | inflate is waiting for these length bytes. | |
145 | */ | |
146 | static int zlib_inflateSyncPacket(z_streamp strm) | |
1da177e4 | 147 | { |
4f3865fb RP |
148 | struct inflate_state *state; |
149 | ||
150 | if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR; | |
151 | state = (struct inflate_state *)strm->state; | |
152 | ||
153 | if (state->mode == STORED && state->bits == 0) { | |
154 | state->mode = TYPE; | |
155 | return Z_OK; | |
156 | } | |
157 | return Z_DATA_ERROR; | |
158 | } | |
159 | ||
160 | /* Macros for inflate(): */ | |
161 | ||
162 | /* check function to use adler32() for zlib or crc32() for gzip */ | |
163 | #define UPDATE(check, buf, len) zlib_adler32(check, buf, len) | |
164 | ||
165 | /* Load registers with state in inflate() for speed */ | |
166 | #define LOAD() \ | |
167 | do { \ | |
168 | put = strm->next_out; \ | |
169 | left = strm->avail_out; \ | |
170 | next = strm->next_in; \ | |
171 | have = strm->avail_in; \ | |
172 | hold = state->hold; \ | |
173 | bits = state->bits; \ | |
174 | } while (0) | |
175 | ||
176 | /* Restore state from registers in inflate() */ | |
177 | #define RESTORE() \ | |
178 | do { \ | |
179 | strm->next_out = put; \ | |
180 | strm->avail_out = left; \ | |
181 | strm->next_in = next; \ | |
182 | strm->avail_in = have; \ | |
183 | state->hold = hold; \ | |
184 | state->bits = bits; \ | |
185 | } while (0) | |
186 | ||
187 | /* Clear the input bit accumulator */ | |
188 | #define INITBITS() \ | |
189 | do { \ | |
190 | hold = 0; \ | |
191 | bits = 0; \ | |
192 | } while (0) | |
193 | ||
194 | /* Get a byte of input into the bit accumulator, or return from inflate() | |
195 | if there is no input available. */ | |
196 | #define PULLBYTE() \ | |
197 | do { \ | |
198 | if (have == 0) goto inf_leave; \ | |
199 | have--; \ | |
200 | hold += (unsigned long)(*next++) << bits; \ | |
201 | bits += 8; \ | |
202 | } while (0) | |
203 | ||
204 | /* Assure that there are at least n bits in the bit accumulator. If there is | |
205 | not enough available input to do that, then return from inflate(). */ | |
206 | #define NEEDBITS(n) \ | |
207 | do { \ | |
208 | while (bits < (unsigned)(n)) \ | |
209 | PULLBYTE(); \ | |
210 | } while (0) | |
211 | ||
212 | /* Return the low n bits of the bit accumulator (n < 16) */ | |
213 | #define BITS(n) \ | |
214 | ((unsigned)hold & ((1U << (n)) - 1)) | |
215 | ||
216 | /* Remove n bits from the bit accumulator */ | |
217 | #define DROPBITS(n) \ | |
218 | do { \ | |
219 | hold >>= (n); \ | |
220 | bits -= (unsigned)(n); \ | |
221 | } while (0) | |
222 | ||
223 | /* Remove zero to seven bits as needed to go to a byte boundary */ | |
224 | #define BYTEBITS() \ | |
225 | do { \ | |
226 | hold >>= bits & 7; \ | |
227 | bits -= bits & 7; \ | |
228 | } while (0) | |
229 | ||
230 | /* Reverse the bytes in a 32-bit value */ | |
231 | #define REVERSE(q) \ | |
232 | ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \ | |
233 | (((q) & 0xff00) << 8) + (((q) & 0xff) << 24)) | |
234 | ||
235 | /* | |
236 | inflate() uses a state machine to process as much input data and generate as | |
237 | much output data as possible before returning. The state machine is | |
238 | structured roughly as follows: | |
239 | ||
240 | for (;;) switch (state) { | |
241 | ... | |
242 | case STATEn: | |
243 | if (not enough input data or output space to make progress) | |
244 | return; | |
245 | ... make progress ... | |
246 | state = STATEm; | |
247 | break; | |
248 | ... | |
249 | } | |
250 | ||
251 | so when inflate() is called again, the same case is attempted again, and | |
252 | if the appropriate resources are provided, the machine proceeds to the | |
253 | next state. The NEEDBITS() macro is usually the way the state evaluates | |
254 | whether it can proceed or should return. NEEDBITS() does the return if | |
255 | the requested bits are not available. The typical use of the BITS macros | |
256 | is: | |
257 | ||
258 | NEEDBITS(n); | |
259 | ... do something with BITS(n) ... | |
260 | DROPBITS(n); | |
261 | ||
262 | where NEEDBITS(n) either returns from inflate() if there isn't enough | |
263 | input left to load n bits into the accumulator, or it continues. BITS(n) | |
264 | gives the low n bits in the accumulator. When done, DROPBITS(n) drops | |
265 | the low n bits off the accumulator. INITBITS() clears the accumulator | |
266 | and sets the number of available bits to zero. BYTEBITS() discards just | |
267 | enough bits to put the accumulator on a byte boundary. After BYTEBITS() | |
268 | and a NEEDBITS(8), then BITS(8) would return the next byte in the stream. | |
269 | ||
270 | NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return | |
271 | if there is no input available. The decoding of variable length codes uses | |
272 | PULLBYTE() directly in order to pull just enough bytes to decode the next | |
273 | code, and no more. | |
274 | ||
275 | Some states loop until they get enough input, making sure that enough | |
276 | state information is maintained to continue the loop where it left off | |
277 | if NEEDBITS() returns in the loop. For example, want, need, and keep | |
278 | would all have to actually be part of the saved state in case NEEDBITS() | |
279 | returns: | |
280 | ||
281 | case STATEw: | |
282 | while (want < need) { | |
283 | NEEDBITS(n); | |
284 | keep[want++] = BITS(n); | |
285 | DROPBITS(n); | |
286 | } | |
287 | state = STATEx; | |
288 | case STATEx: | |
289 | ||
290 | As shown above, if the next state is also the next case, then the break | |
291 | is omitted. | |
292 | ||
293 | A state may also return if there is not enough output space available to | |
294 | complete that state. Those states are copying stored data, writing a | |
295 | literal byte, and copying a matching string. | |
296 | ||
297 | When returning, a "goto inf_leave" is used to update the total counters, | |
298 | update the check value, and determine whether any progress has been made | |
299 | during that inflate() call in order to return the proper return code. | |
300 | Progress is defined as a change in either strm->avail_in or strm->avail_out. | |
301 | When there is a window, goto inf_leave will update the window with the last | |
302 | output written. If a goto inf_leave occurs in the middle of decompression | |
303 | and there is no window currently, goto inf_leave will create one and copy | |
304 | output to the window for the next call of inflate(). | |
305 | ||
306 | In this implementation, the flush parameter of inflate() only affects the | |
307 | return code (per zlib.h). inflate() always writes as much as possible to | |
308 | strm->next_out, given the space available and the provided input--the effect | |
309 | documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers | |
310 | the allocation of and copying into a sliding window until necessary, which | |
311 | provides the effect documented in zlib.h for Z_FINISH when the entire input | |
312 | stream available. So the only thing the flush parameter actually does is: | |
313 | when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it | |
314 | will return Z_BUF_ERROR if it has not reached the end of the stream. | |
315 | */ | |
316 | ||
317 | int zlib_inflate(z_streamp strm, int flush) | |
318 | { | |
319 | struct inflate_state *state; | |
8336793b DV |
320 | const unsigned char *next; /* next input */ |
321 | unsigned char *put; /* next output */ | |
4f3865fb RP |
322 | unsigned have, left; /* available input and output */ |
323 | unsigned long hold; /* bit buffer */ | |
324 | unsigned bits; /* bits in bit buffer */ | |
325 | unsigned in, out; /* save starting available input and output */ | |
326 | unsigned copy; /* number of stored or match bytes to copy */ | |
8336793b | 327 | unsigned char *from; /* where to copy match bytes from */ |
4f3865fb RP |
328 | code this; /* current decoding table entry */ |
329 | code last; /* parent table entry */ | |
330 | unsigned len; /* length to copy for repeats, bits to drop */ | |
331 | int ret; /* return code */ | |
332 | static const unsigned short order[19] = /* permutation of code lengths */ | |
333 | {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; | |
334 | ||
31925c88 PK |
335 | /* Do not check for strm->next_out == NULL here as ppc zImage |
336 | inflates to strm->next_out = 0 */ | |
337 | ||
338 | if (strm == NULL || strm->state == NULL || | |
4f3865fb RP |
339 | (strm->next_in == NULL && strm->avail_in != 0)) |
340 | return Z_STREAM_ERROR; | |
341 | ||
342 | state = (struct inflate_state *)strm->state; | |
343 | ||
344 | if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */ | |
345 | LOAD(); | |
346 | in = have; | |
347 | out = left; | |
348 | ret = Z_OK; | |
349 | for (;;) | |
350 | switch (state->mode) { | |
351 | case HEAD: | |
352 | if (state->wrap == 0) { | |
353 | state->mode = TYPEDO; | |
354 | break; | |
355 | } | |
356 | NEEDBITS(16); | |
357 | if ( | |
358 | ((BITS(8) << 8) + (hold >> 8)) % 31) { | |
359 | strm->msg = (char *)"incorrect header check"; | |
360 | state->mode = BAD; | |
361 | break; | |
362 | } | |
363 | if (BITS(4) != Z_DEFLATED) { | |
364 | strm->msg = (char *)"unknown compression method"; | |
365 | state->mode = BAD; | |
366 | break; | |
367 | } | |
368 | DROPBITS(4); | |
369 | len = BITS(4) + 8; | |
370 | if (len > state->wbits) { | |
371 | strm->msg = (char *)"invalid window size"; | |
372 | state->mode = BAD; | |
373 | break; | |
374 | } | |
375 | state->dmax = 1U << len; | |
376 | strm->adler = state->check = zlib_adler32(0L, NULL, 0); | |
377 | state->mode = hold & 0x200 ? DICTID : TYPE; | |
378 | INITBITS(); | |
379 | break; | |
380 | case DICTID: | |
381 | NEEDBITS(32); | |
382 | strm->adler = state->check = REVERSE(hold); | |
383 | INITBITS(); | |
384 | state->mode = DICT; | |
7a20c2fa | 385 | /* fall through */ |
4f3865fb RP |
386 | case DICT: |
387 | if (state->havedict == 0) { | |
388 | RESTORE(); | |
389 | return Z_NEED_DICT; | |
390 | } | |
391 | strm->adler = state->check = zlib_adler32(0L, NULL, 0); | |
392 | state->mode = TYPE; | |
7a20c2fa | 393 | /* fall through */ |
4f3865fb RP |
394 | case TYPE: |
395 | if (flush == Z_BLOCK) goto inf_leave; | |
7a20c2fa | 396 | /* fall through */ |
4f3865fb RP |
397 | case TYPEDO: |
398 | if (state->last) { | |
399 | BYTEBITS(); | |
400 | state->mode = CHECK; | |
401 | break; | |
402 | } | |
403 | NEEDBITS(3); | |
404 | state->last = BITS(1); | |
405 | DROPBITS(1); | |
406 | switch (BITS(2)) { | |
407 | case 0: /* stored block */ | |
408 | state->mode = STORED; | |
409 | break; | |
410 | case 1: /* fixed block */ | |
411 | zlib_fixedtables(state); | |
412 | state->mode = LEN; /* decode codes */ | |
413 | break; | |
414 | case 2: /* dynamic block */ | |
415 | state->mode = TABLE; | |
416 | break; | |
417 | case 3: | |
418 | strm->msg = (char *)"invalid block type"; | |
419 | state->mode = BAD; | |
420 | } | |
421 | DROPBITS(2); | |
422 | break; | |
423 | case STORED: | |
424 | BYTEBITS(); /* go to byte boundary */ | |
425 | NEEDBITS(32); | |
426 | if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { | |
427 | strm->msg = (char *)"invalid stored block lengths"; | |
428 | state->mode = BAD; | |
429 | break; | |
430 | } | |
431 | state->length = (unsigned)hold & 0xffff; | |
432 | INITBITS(); | |
433 | state->mode = COPY; | |
7a20c2fa | 434 | /* fall through */ |
4f3865fb RP |
435 | case COPY: |
436 | copy = state->length; | |
437 | if (copy) { | |
438 | if (copy > have) copy = have; | |
439 | if (copy > left) copy = left; | |
440 | if (copy == 0) goto inf_leave; | |
441 | memcpy(put, next, copy); | |
442 | have -= copy; | |
443 | next += copy; | |
444 | left -= copy; | |
445 | put += copy; | |
446 | state->length -= copy; | |
447 | break; | |
448 | } | |
449 | state->mode = TYPE; | |
450 | break; | |
451 | case TABLE: | |
452 | NEEDBITS(14); | |
453 | state->nlen = BITS(5) + 257; | |
454 | DROPBITS(5); | |
455 | state->ndist = BITS(5) + 1; | |
456 | DROPBITS(5); | |
457 | state->ncode = BITS(4) + 4; | |
458 | DROPBITS(4); | |
459 | #ifndef PKZIP_BUG_WORKAROUND | |
460 | if (state->nlen > 286 || state->ndist > 30) { | |
461 | strm->msg = (char *)"too many length or distance symbols"; | |
462 | state->mode = BAD; | |
463 | break; | |
464 | } | |
465 | #endif | |
466 | state->have = 0; | |
467 | state->mode = LENLENS; | |
7a20c2fa | 468 | /* fall through */ |
4f3865fb RP |
469 | case LENLENS: |
470 | while (state->have < state->ncode) { | |
471 | NEEDBITS(3); | |
472 | state->lens[order[state->have++]] = (unsigned short)BITS(3); | |
473 | DROPBITS(3); | |
474 | } | |
475 | while (state->have < 19) | |
476 | state->lens[order[state->have++]] = 0; | |
477 | state->next = state->codes; | |
478 | state->lencode = (code const *)(state->next); | |
479 | state->lenbits = 7; | |
480 | ret = zlib_inflate_table(CODES, state->lens, 19, &(state->next), | |
481 | &(state->lenbits), state->work); | |
482 | if (ret) { | |
483 | strm->msg = (char *)"invalid code lengths set"; | |
484 | state->mode = BAD; | |
485 | break; | |
486 | } | |
487 | state->have = 0; | |
488 | state->mode = CODELENS; | |
7a20c2fa | 489 | /* fall through */ |
4f3865fb RP |
490 | case CODELENS: |
491 | while (state->have < state->nlen + state->ndist) { | |
492 | for (;;) { | |
493 | this = state->lencode[BITS(state->lenbits)]; | |
494 | if ((unsigned)(this.bits) <= bits) break; | |
495 | PULLBYTE(); | |
496 | } | |
497 | if (this.val < 16) { | |
498 | NEEDBITS(this.bits); | |
499 | DROPBITS(this.bits); | |
500 | state->lens[state->have++] = this.val; | |
501 | } | |
502 | else { | |
503 | if (this.val == 16) { | |
504 | NEEDBITS(this.bits + 2); | |
505 | DROPBITS(this.bits); | |
506 | if (state->have == 0) { | |
507 | strm->msg = (char *)"invalid bit length repeat"; | |
508 | state->mode = BAD; | |
509 | break; | |
510 | } | |
511 | len = state->lens[state->have - 1]; | |
512 | copy = 3 + BITS(2); | |
513 | DROPBITS(2); | |
514 | } | |
515 | else if (this.val == 17) { | |
516 | NEEDBITS(this.bits + 3); | |
517 | DROPBITS(this.bits); | |
518 | len = 0; | |
519 | copy = 3 + BITS(3); | |
520 | DROPBITS(3); | |
521 | } | |
522 | else { | |
523 | NEEDBITS(this.bits + 7); | |
524 | DROPBITS(this.bits); | |
525 | len = 0; | |
526 | copy = 11 + BITS(7); | |
527 | DROPBITS(7); | |
528 | } | |
529 | if (state->have + copy > state->nlen + state->ndist) { | |
530 | strm->msg = (char *)"invalid bit length repeat"; | |
531 | state->mode = BAD; | |
532 | break; | |
533 | } | |
534 | while (copy--) | |
535 | state->lens[state->have++] = (unsigned short)len; | |
536 | } | |
537 | } | |
538 | ||
539 | /* handle error breaks in while */ | |
540 | if (state->mode == BAD) break; | |
541 | ||
542 | /* build code tables */ | |
543 | state->next = state->codes; | |
544 | state->lencode = (code const *)(state->next); | |
545 | state->lenbits = 9; | |
546 | ret = zlib_inflate_table(LENS, state->lens, state->nlen, &(state->next), | |
547 | &(state->lenbits), state->work); | |
548 | if (ret) { | |
549 | strm->msg = (char *)"invalid literal/lengths set"; | |
550 | state->mode = BAD; | |
551 | break; | |
552 | } | |
553 | state->distcode = (code const *)(state->next); | |
554 | state->distbits = 6; | |
555 | ret = zlib_inflate_table(DISTS, state->lens + state->nlen, state->ndist, | |
556 | &(state->next), &(state->distbits), state->work); | |
557 | if (ret) { | |
558 | strm->msg = (char *)"invalid distances set"; | |
559 | state->mode = BAD; | |
560 | break; | |
561 | } | |
562 | state->mode = LEN; | |
7a20c2fa | 563 | /* fall through */ |
4f3865fb RP |
564 | case LEN: |
565 | if (have >= 6 && left >= 258) { | |
566 | RESTORE(); | |
567 | inflate_fast(strm, out); | |
568 | LOAD(); | |
569 | break; | |
570 | } | |
571 | for (;;) { | |
572 | this = state->lencode[BITS(state->lenbits)]; | |
573 | if ((unsigned)(this.bits) <= bits) break; | |
574 | PULLBYTE(); | |
575 | } | |
576 | if (this.op && (this.op & 0xf0) == 0) { | |
577 | last = this; | |
578 | for (;;) { | |
579 | this = state->lencode[last.val + | |
580 | (BITS(last.bits + last.op) >> last.bits)]; | |
581 | if ((unsigned)(last.bits + this.bits) <= bits) break; | |
582 | PULLBYTE(); | |
583 | } | |
584 | DROPBITS(last.bits); | |
585 | } | |
586 | DROPBITS(this.bits); | |
587 | state->length = (unsigned)this.val; | |
588 | if ((int)(this.op) == 0) { | |
589 | state->mode = LIT; | |
590 | break; | |
591 | } | |
592 | if (this.op & 32) { | |
593 | state->mode = TYPE; | |
594 | break; | |
595 | } | |
596 | if (this.op & 64) { | |
597 | strm->msg = (char *)"invalid literal/length code"; | |
598 | state->mode = BAD; | |
599 | break; | |
600 | } | |
601 | state->extra = (unsigned)(this.op) & 15; | |
602 | state->mode = LENEXT; | |
7a20c2fa | 603 | /* fall through */ |
4f3865fb RP |
604 | case LENEXT: |
605 | if (state->extra) { | |
606 | NEEDBITS(state->extra); | |
607 | state->length += BITS(state->extra); | |
608 | DROPBITS(state->extra); | |
609 | } | |
610 | state->mode = DIST; | |
7a20c2fa | 611 | /* fall through */ |
4f3865fb RP |
612 | case DIST: |
613 | for (;;) { | |
614 | this = state->distcode[BITS(state->distbits)]; | |
615 | if ((unsigned)(this.bits) <= bits) break; | |
616 | PULLBYTE(); | |
617 | } | |
618 | if ((this.op & 0xf0) == 0) { | |
619 | last = this; | |
620 | for (;;) { | |
621 | this = state->distcode[last.val + | |
622 | (BITS(last.bits + last.op) >> last.bits)]; | |
623 | if ((unsigned)(last.bits + this.bits) <= bits) break; | |
624 | PULLBYTE(); | |
625 | } | |
626 | DROPBITS(last.bits); | |
627 | } | |
628 | DROPBITS(this.bits); | |
629 | if (this.op & 64) { | |
630 | strm->msg = (char *)"invalid distance code"; | |
631 | state->mode = BAD; | |
632 | break; | |
633 | } | |
634 | state->offset = (unsigned)this.val; | |
635 | state->extra = (unsigned)(this.op) & 15; | |
636 | state->mode = DISTEXT; | |
7a20c2fa | 637 | /* fall through */ |
4f3865fb RP |
638 | case DISTEXT: |
639 | if (state->extra) { | |
640 | NEEDBITS(state->extra); | |
641 | state->offset += BITS(state->extra); | |
642 | DROPBITS(state->extra); | |
643 | } | |
644 | #ifdef INFLATE_STRICT | |
645 | if (state->offset > state->dmax) { | |
646 | strm->msg = (char *)"invalid distance too far back"; | |
647 | state->mode = BAD; | |
648 | break; | |
649 | } | |
650 | #endif | |
651 | if (state->offset > state->whave + out - left) { | |
652 | strm->msg = (char *)"invalid distance too far back"; | |
653 | state->mode = BAD; | |
654 | break; | |
655 | } | |
656 | state->mode = MATCH; | |
7a20c2fa | 657 | /* fall through */ |
4f3865fb RP |
658 | case MATCH: |
659 | if (left == 0) goto inf_leave; | |
660 | copy = out - left; | |
661 | if (state->offset > copy) { /* copy from window */ | |
662 | copy = state->offset - copy; | |
663 | if (copy > state->write) { | |
664 | copy -= state->write; | |
665 | from = state->window + (state->wsize - copy); | |
666 | } | |
667 | else | |
668 | from = state->window + (state->write - copy); | |
669 | if (copy > state->length) copy = state->length; | |
670 | } | |
671 | else { /* copy from output */ | |
672 | from = put - state->offset; | |
673 | copy = state->length; | |
674 | } | |
675 | if (copy > left) copy = left; | |
676 | left -= copy; | |
677 | state->length -= copy; | |
678 | do { | |
679 | *put++ = *from++; | |
680 | } while (--copy); | |
681 | if (state->length == 0) state->mode = LEN; | |
682 | break; | |
683 | case LIT: | |
684 | if (left == 0) goto inf_leave; | |
685 | *put++ = (unsigned char)(state->length); | |
686 | left--; | |
687 | state->mode = LEN; | |
688 | break; | |
689 | case CHECK: | |
690 | if (state->wrap) { | |
691 | NEEDBITS(32); | |
692 | out -= left; | |
693 | strm->total_out += out; | |
694 | state->total += out; | |
695 | if (out) | |
696 | strm->adler = state->check = | |
697 | UPDATE(state->check, put - out, out); | |
698 | out = left; | |
699 | if (( | |
700 | REVERSE(hold)) != state->check) { | |
701 | strm->msg = (char *)"incorrect data check"; | |
702 | state->mode = BAD; | |
703 | break; | |
704 | } | |
705 | INITBITS(); | |
706 | } | |
707 | state->mode = DONE; | |
7a20c2fa | 708 | /* fall through */ |
4f3865fb RP |
709 | case DONE: |
710 | ret = Z_STREAM_END; | |
711 | goto inf_leave; | |
712 | case BAD: | |
713 | ret = Z_DATA_ERROR; | |
714 | goto inf_leave; | |
715 | case MEM: | |
716 | return Z_MEM_ERROR; | |
717 | case SYNC: | |
718 | default: | |
719 | return Z_STREAM_ERROR; | |
720 | } | |
721 | ||
722 | /* | |
723 | Return from inflate(), updating the total counts and the check value. | |
724 | If there was no progress during the inflate() call, return a buffer | |
725 | error. Call zlib_updatewindow() to create and/or update the window state. | |
726 | */ | |
727 | inf_leave: | |
728 | RESTORE(); | |
729 | if (state->wsize || (state->mode < CHECK && out != strm->avail_out)) | |
730 | zlib_updatewindow(strm, out); | |
731 | ||
732 | in -= strm->avail_in; | |
733 | out -= strm->avail_out; | |
734 | strm->total_in += in; | |
735 | strm->total_out += out; | |
736 | state->total += out; | |
737 | if (state->wrap && out) | |
738 | strm->adler = state->check = | |
739 | UPDATE(state->check, strm->next_out - out, out); | |
740 | ||
741 | strm->data_type = state->bits + (state->last ? 64 : 0) + | |
742 | (state->mode == TYPE ? 128 : 0); | |
4f3865fb RP |
743 | |
744 | if (flush == Z_PACKET_FLUSH && ret == Z_OK && | |
f0ac6758 | 745 | strm->avail_out != 0 && strm->avail_in == 0) |
4f3865fb | 746 | return zlib_inflateSyncPacket(strm); |
f0ac6758 RP |
747 | |
748 | if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK) | |
749 | ret = Z_BUF_ERROR; | |
750 | ||
4f3865fb RP |
751 | return ret; |
752 | } | |
753 | ||
754 | int zlib_inflateEnd(z_streamp strm) | |
755 | { | |
756 | if (strm == NULL || strm->state == NULL) | |
757 | return Z_STREAM_ERROR; | |
1da177e4 LT |
758 | return Z_OK; |
759 | } | |
760 | ||
4f3865fb RP |
761 | /* |
762 | * This subroutine adds the data at next_in/avail_in to the output history | |
763 | * without performing any output. The output buffer must be "caught up"; | |
764 | * i.e. no pending output but this should always be the case. The state must | |
765 | * be waiting on the start of a block (i.e. mode == TYPE or HEAD). On exit, | |
766 | * the output will also be caught up, and the checksum will have been updated | |
767 | * if need be. | |
768 | */ | |
769 | int zlib_inflateIncomp(z_stream *z) | |
1da177e4 | 770 | { |
4f3865fb RP |
771 | struct inflate_state *state = (struct inflate_state *)z->state; |
772 | Byte *saved_no = z->next_out; | |
773 | uInt saved_ao = z->avail_out; | |
774 | ||
775 | if (state->mode != TYPE && state->mode != HEAD) | |
776 | return Z_DATA_ERROR; | |
777 | ||
778 | /* Setup some variables to allow misuse of updateWindow */ | |
779 | z->avail_out = 0; | |
8336793b | 780 | z->next_out = (unsigned char*)z->next_in + z->avail_in; |
4f3865fb RP |
781 | |
782 | zlib_updatewindow(z, z->avail_in); | |
783 | ||
784 | /* Restore saved variables */ | |
785 | z->avail_out = saved_ao; | |
786 | z->next_out = saved_no; | |
787 | ||
788 | z->adler = state->check = | |
789 | UPDATE(state->check, z->next_in, z->avail_in); | |
790 | ||
791 | z->total_out += z->avail_in; | |
792 | z->total_in += z->avail_in; | |
793 | z->next_in += z->avail_in; | |
794 | state->total += z->avail_in; | |
795 | z->avail_in = 0; | |
796 | ||
797 | return Z_OK; | |
1da177e4 | 798 | } |