Commit | Line | Data |
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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 | ||
12619610 MZ |
18 | /* architecture-specific bits */ |
19 | #ifdef CONFIG_ZLIB_DFLTCC | |
9fec9f8e | 20 | # include "../zlib_dfltcc/dfltcc_inflate.h" |
12619610 MZ |
21 | #else |
22 | #define INFLATE_RESET_HOOK(strm) do {} while (0) | |
23 | #define INFLATE_TYPEDO_HOOK(strm, flush) do {} while (0) | |
24 | #define INFLATE_NEED_UPDATEWINDOW(strm) 1 | |
25 | #define INFLATE_NEED_CHECKSUM(strm) 1 | |
26 | #endif | |
27 | ||
1da177e4 LT |
28 | int zlib_inflate_workspacesize(void) |
29 | { | |
4f3865fb | 30 | return sizeof(struct inflate_workspace); |
1da177e4 LT |
31 | } |
32 | ||
4f3865fb RP |
33 | int zlib_inflateReset(z_streamp strm) |
34 | { | |
35 | struct inflate_state *state; | |
36 | ||
37 | if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR; | |
38 | state = (struct inflate_state *)strm->state; | |
39 | strm->total_in = strm->total_out = state->total = 0; | |
40 | strm->msg = NULL; | |
41 | strm->adler = 1; /* to support ill-conceived Java test suite */ | |
42 | state->mode = HEAD; | |
43 | state->last = 0; | |
44 | state->havedict = 0; | |
45 | state->dmax = 32768U; | |
46 | state->hold = 0; | |
47 | state->bits = 0; | |
48 | state->lencode = state->distcode = state->next = state->codes; | |
1da177e4 | 49 | |
4f3865fb RP |
50 | /* Initialise Window */ |
51 | state->wsize = 1U << state->wbits; | |
52 | state->write = 0; | |
53 | state->whave = 0; | |
54 | ||
12619610 | 55 | INFLATE_RESET_HOOK(strm); |
4f3865fb RP |
56 | return Z_OK; |
57 | } | |
58 | ||
4f3865fb RP |
59 | int zlib_inflateInit2(z_streamp strm, int windowBits) |
60 | { | |
61 | struct inflate_state *state; | |
62 | ||
63 | if (strm == NULL) return Z_STREAM_ERROR; | |
64 | strm->msg = NULL; /* in case we return an error */ | |
65 | ||
66 | state = &WS(strm)->inflate_state; | |
67 | strm->state = (struct internal_state *)state; | |
68 | ||
69 | if (windowBits < 0) { | |
70 | state->wrap = 0; | |
71 | windowBits = -windowBits; | |
72 | } | |
73 | else { | |
74 | state->wrap = (windowBits >> 4) + 1; | |
75 | } | |
76 | if (windowBits < 8 || windowBits > 15) { | |
77 | return Z_STREAM_ERROR; | |
78 | } | |
79 | state->wbits = (unsigned)windowBits; | |
12619610 MZ |
80 | #ifdef CONFIG_ZLIB_DFLTCC |
81 | /* | |
82 | * DFLTCC requires the window to be page aligned. | |
83 | * Thus, we overallocate and take the aligned portion of the buffer. | |
84 | */ | |
85 | state->window = PTR_ALIGN(&WS(strm)->working_window[0], PAGE_SIZE); | |
86 | #else | |
4f3865fb | 87 | state->window = &WS(strm)->working_window[0]; |
12619610 | 88 | #endif |
1da177e4 | 89 | |
4f3865fb RP |
90 | return zlib_inflateReset(strm); |
91 | } | |
1da177e4 | 92 | |
4f3865fb RP |
93 | /* |
94 | Return state with length and distance decoding tables and index sizes set to | |
95 | fixed code decoding. This returns fixed tables from inffixed.h. | |
96 | */ | |
97 | static void zlib_fixedtables(struct inflate_state *state) | |
1da177e4 | 98 | { |
4f3865fb RP |
99 | # include "inffixed.h" |
100 | state->lencode = lenfix; | |
101 | state->lenbits = 9; | |
102 | state->distcode = distfix; | |
103 | state->distbits = 5; | |
1da177e4 LT |
104 | } |
105 | ||
106 | ||
4f3865fb RP |
107 | /* |
108 | Update the window with the last wsize (normally 32K) bytes written before | |
109 | returning. This is only called when a window is already in use, or when | |
110 | output has been written during this inflate call, but the end of the deflate | |
111 | stream has not been reached yet. It is also called to window dictionary data | |
112 | when a dictionary is loaded. | |
113 | ||
114 | Providing output buffers larger than 32K to inflate() should provide a speed | |
115 | advantage, since only the last 32K of output is copied to the sliding window | |
116 | upon return from inflate(), and since all distances after the first 32K of | |
117 | output will fall in the output data, making match copies simpler and faster. | |
118 | The advantage may be dependent on the size of the processor's data caches. | |
119 | */ | |
120 | static void zlib_updatewindow(z_streamp strm, unsigned out) | |
1da177e4 | 121 | { |
4f3865fb RP |
122 | struct inflate_state *state; |
123 | unsigned copy, dist; | |
124 | ||
125 | state = (struct inflate_state *)strm->state; | |
126 | ||
127 | /* copy state->wsize or less output bytes into the circular window */ | |
128 | copy = out - strm->avail_out; | |
129 | if (copy >= state->wsize) { | |
130 | memcpy(state->window, strm->next_out - state->wsize, state->wsize); | |
131 | state->write = 0; | |
132 | state->whave = state->wsize; | |
133 | } | |
134 | else { | |
135 | dist = state->wsize - state->write; | |
136 | if (dist > copy) dist = copy; | |
137 | memcpy(state->window + state->write, strm->next_out - copy, dist); | |
138 | copy -= dist; | |
139 | if (copy) { | |
140 | memcpy(state->window, strm->next_out - copy, copy); | |
141 | state->write = copy; | |
142 | state->whave = state->wsize; | |
143 | } | |
144 | else { | |
145 | state->write += dist; | |
146 | if (state->write == state->wsize) state->write = 0; | |
147 | if (state->whave < state->wsize) state->whave += dist; | |
148 | } | |
149 | } | |
1da177e4 LT |
150 | } |
151 | ||
152 | ||
153 | /* | |
154 | * At the end of a Deflate-compressed PPP packet, we expect to have seen | |
155 | * a `stored' block type value but not the (zero) length bytes. | |
156 | */ | |
4f3865fb RP |
157 | /* |
158 | Returns true if inflate is currently at the end of a block generated by | |
159 | Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP | |
160 | implementation to provide an additional safety check. PPP uses | |
161 | Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored | |
162 | block. When decompressing, PPP checks that at the end of input packet, | |
163 | inflate is waiting for these length bytes. | |
164 | */ | |
165 | static int zlib_inflateSyncPacket(z_streamp strm) | |
1da177e4 | 166 | { |
4f3865fb RP |
167 | struct inflate_state *state; |
168 | ||
169 | if (strm == NULL || strm->state == NULL) return Z_STREAM_ERROR; | |
170 | state = (struct inflate_state *)strm->state; | |
171 | ||
172 | if (state->mode == STORED && state->bits == 0) { | |
173 | state->mode = TYPE; | |
174 | return Z_OK; | |
175 | } | |
176 | return Z_DATA_ERROR; | |
177 | } | |
178 | ||
179 | /* Macros for inflate(): */ | |
180 | ||
181 | /* check function to use adler32() for zlib or crc32() for gzip */ | |
182 | #define UPDATE(check, buf, len) zlib_adler32(check, buf, len) | |
183 | ||
184 | /* Load registers with state in inflate() for speed */ | |
185 | #define LOAD() \ | |
186 | do { \ | |
187 | put = strm->next_out; \ | |
188 | left = strm->avail_out; \ | |
189 | next = strm->next_in; \ | |
190 | have = strm->avail_in; \ | |
191 | hold = state->hold; \ | |
192 | bits = state->bits; \ | |
193 | } while (0) | |
194 | ||
195 | /* Restore state from registers in inflate() */ | |
196 | #define RESTORE() \ | |
197 | do { \ | |
198 | strm->next_out = put; \ | |
199 | strm->avail_out = left; \ | |
200 | strm->next_in = next; \ | |
201 | strm->avail_in = have; \ | |
202 | state->hold = hold; \ | |
203 | state->bits = bits; \ | |
204 | } while (0) | |
205 | ||
206 | /* Clear the input bit accumulator */ | |
207 | #define INITBITS() \ | |
208 | do { \ | |
209 | hold = 0; \ | |
210 | bits = 0; \ | |
211 | } while (0) | |
212 | ||
213 | /* Get a byte of input into the bit accumulator, or return from inflate() | |
214 | if there is no input available. */ | |
215 | #define PULLBYTE() \ | |
216 | do { \ | |
217 | if (have == 0) goto inf_leave; \ | |
218 | have--; \ | |
219 | hold += (unsigned long)(*next++) << bits; \ | |
220 | bits += 8; \ | |
221 | } while (0) | |
222 | ||
223 | /* Assure that there are at least n bits in the bit accumulator. If there is | |
224 | not enough available input to do that, then return from inflate(). */ | |
225 | #define NEEDBITS(n) \ | |
226 | do { \ | |
227 | while (bits < (unsigned)(n)) \ | |
228 | PULLBYTE(); \ | |
229 | } while (0) | |
230 | ||
231 | /* Return the low n bits of the bit accumulator (n < 16) */ | |
232 | #define BITS(n) \ | |
233 | ((unsigned)hold & ((1U << (n)) - 1)) | |
234 | ||
235 | /* Remove n bits from the bit accumulator */ | |
236 | #define DROPBITS(n) \ | |
237 | do { \ | |
238 | hold >>= (n); \ | |
239 | bits -= (unsigned)(n); \ | |
240 | } while (0) | |
241 | ||
242 | /* Remove zero to seven bits as needed to go to a byte boundary */ | |
243 | #define BYTEBITS() \ | |
244 | do { \ | |
245 | hold >>= bits & 7; \ | |
246 | bits -= bits & 7; \ | |
247 | } while (0) | |
248 | ||
4f3865fb RP |
249 | /* |
250 | inflate() uses a state machine to process as much input data and generate as | |
251 | much output data as possible before returning. The state machine is | |
252 | structured roughly as follows: | |
253 | ||
254 | for (;;) switch (state) { | |
255 | ... | |
256 | case STATEn: | |
257 | if (not enough input data or output space to make progress) | |
258 | return; | |
259 | ... make progress ... | |
260 | state = STATEm; | |
261 | break; | |
262 | ... | |
263 | } | |
264 | ||
265 | so when inflate() is called again, the same case is attempted again, and | |
266 | if the appropriate resources are provided, the machine proceeds to the | |
267 | next state. The NEEDBITS() macro is usually the way the state evaluates | |
268 | whether it can proceed or should return. NEEDBITS() does the return if | |
269 | the requested bits are not available. The typical use of the BITS macros | |
270 | is: | |
271 | ||
272 | NEEDBITS(n); | |
273 | ... do something with BITS(n) ... | |
274 | DROPBITS(n); | |
275 | ||
276 | where NEEDBITS(n) either returns from inflate() if there isn't enough | |
277 | input left to load n bits into the accumulator, or it continues. BITS(n) | |
278 | gives the low n bits in the accumulator. When done, DROPBITS(n) drops | |
279 | the low n bits off the accumulator. INITBITS() clears the accumulator | |
280 | and sets the number of available bits to zero. BYTEBITS() discards just | |
281 | enough bits to put the accumulator on a byte boundary. After BYTEBITS() | |
282 | and a NEEDBITS(8), then BITS(8) would return the next byte in the stream. | |
283 | ||
284 | NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return | |
285 | if there is no input available. The decoding of variable length codes uses | |
286 | PULLBYTE() directly in order to pull just enough bytes to decode the next | |
287 | code, and no more. | |
288 | ||
289 | Some states loop until they get enough input, making sure that enough | |
290 | state information is maintained to continue the loop where it left off | |
291 | if NEEDBITS() returns in the loop. For example, want, need, and keep | |
292 | would all have to actually be part of the saved state in case NEEDBITS() | |
293 | returns: | |
294 | ||
295 | case STATEw: | |
296 | while (want < need) { | |
297 | NEEDBITS(n); | |
298 | keep[want++] = BITS(n); | |
299 | DROPBITS(n); | |
300 | } | |
301 | state = STATEx; | |
302 | case STATEx: | |
303 | ||
304 | As shown above, if the next state is also the next case, then the break | |
305 | is omitted. | |
306 | ||
307 | A state may also return if there is not enough output space available to | |
308 | complete that state. Those states are copying stored data, writing a | |
309 | literal byte, and copying a matching string. | |
310 | ||
311 | When returning, a "goto inf_leave" is used to update the total counters, | |
312 | update the check value, and determine whether any progress has been made | |
313 | during that inflate() call in order to return the proper return code. | |
314 | Progress is defined as a change in either strm->avail_in or strm->avail_out. | |
315 | When there is a window, goto inf_leave will update the window with the last | |
316 | output written. If a goto inf_leave occurs in the middle of decompression | |
317 | and there is no window currently, goto inf_leave will create one and copy | |
318 | output to the window for the next call of inflate(). | |
319 | ||
320 | In this implementation, the flush parameter of inflate() only affects the | |
321 | return code (per zlib.h). inflate() always writes as much as possible to | |
322 | strm->next_out, given the space available and the provided input--the effect | |
323 | documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers | |
324 | the allocation of and copying into a sliding window until necessary, which | |
325 | provides the effect documented in zlib.h for Z_FINISH when the entire input | |
326 | stream available. So the only thing the flush parameter actually does is: | |
327 | when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it | |
328 | will return Z_BUF_ERROR if it has not reached the end of the stream. | |
329 | */ | |
330 | ||
331 | int zlib_inflate(z_streamp strm, int flush) | |
332 | { | |
333 | struct inflate_state *state; | |
8336793b DV |
334 | const unsigned char *next; /* next input */ |
335 | unsigned char *put; /* next output */ | |
4f3865fb RP |
336 | unsigned have, left; /* available input and output */ |
337 | unsigned long hold; /* bit buffer */ | |
338 | unsigned bits; /* bits in bit buffer */ | |
339 | unsigned in, out; /* save starting available input and output */ | |
340 | unsigned copy; /* number of stored or match bytes to copy */ | |
8336793b | 341 | unsigned char *from; /* where to copy match bytes from */ |
4f3865fb RP |
342 | code this; /* current decoding table entry */ |
343 | code last; /* parent table entry */ | |
344 | unsigned len; /* length to copy for repeats, bits to drop */ | |
345 | int ret; /* return code */ | |
346 | static const unsigned short order[19] = /* permutation of code lengths */ | |
347 | {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; | |
348 | ||
31925c88 PK |
349 | /* Do not check for strm->next_out == NULL here as ppc zImage |
350 | inflates to strm->next_out = 0 */ | |
351 | ||
352 | if (strm == NULL || strm->state == NULL || | |
4f3865fb RP |
353 | (strm->next_in == NULL && strm->avail_in != 0)) |
354 | return Z_STREAM_ERROR; | |
355 | ||
356 | state = (struct inflate_state *)strm->state; | |
357 | ||
358 | if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */ | |
359 | LOAD(); | |
360 | in = have; | |
361 | out = left; | |
362 | ret = Z_OK; | |
363 | for (;;) | |
364 | switch (state->mode) { | |
365 | case HEAD: | |
366 | if (state->wrap == 0) { | |
367 | state->mode = TYPEDO; | |
368 | break; | |
369 | } | |
370 | NEEDBITS(16); | |
371 | if ( | |
372 | ((BITS(8) << 8) + (hold >> 8)) % 31) { | |
373 | strm->msg = (char *)"incorrect header check"; | |
374 | state->mode = BAD; | |
375 | break; | |
376 | } | |
377 | if (BITS(4) != Z_DEFLATED) { | |
378 | strm->msg = (char *)"unknown compression method"; | |
379 | state->mode = BAD; | |
380 | break; | |
381 | } | |
382 | DROPBITS(4); | |
383 | len = BITS(4) + 8; | |
384 | if (len > state->wbits) { | |
385 | strm->msg = (char *)"invalid window size"; | |
386 | state->mode = BAD; | |
387 | break; | |
388 | } | |
389 | state->dmax = 1U << len; | |
390 | strm->adler = state->check = zlib_adler32(0L, NULL, 0); | |
391 | state->mode = hold & 0x200 ? DICTID : TYPE; | |
392 | INITBITS(); | |
393 | break; | |
394 | case DICTID: | |
395 | NEEDBITS(32); | |
396 | strm->adler = state->check = REVERSE(hold); | |
397 | INITBITS(); | |
398 | state->mode = DICT; | |
36f9ff9e | 399 | fallthrough; |
4f3865fb RP |
400 | case DICT: |
401 | if (state->havedict == 0) { | |
402 | RESTORE(); | |
403 | return Z_NEED_DICT; | |
404 | } | |
405 | strm->adler = state->check = zlib_adler32(0L, NULL, 0); | |
406 | state->mode = TYPE; | |
36f9ff9e | 407 | fallthrough; |
4f3865fb RP |
408 | case TYPE: |
409 | if (flush == Z_BLOCK) goto inf_leave; | |
36f9ff9e | 410 | fallthrough; |
4f3865fb | 411 | case TYPEDO: |
12619610 | 412 | INFLATE_TYPEDO_HOOK(strm, flush); |
4f3865fb RP |
413 | if (state->last) { |
414 | BYTEBITS(); | |
415 | state->mode = CHECK; | |
416 | break; | |
417 | } | |
418 | NEEDBITS(3); | |
419 | state->last = BITS(1); | |
420 | DROPBITS(1); | |
421 | switch (BITS(2)) { | |
422 | case 0: /* stored block */ | |
423 | state->mode = STORED; | |
424 | break; | |
425 | case 1: /* fixed block */ | |
426 | zlib_fixedtables(state); | |
427 | state->mode = LEN; /* decode codes */ | |
428 | break; | |
429 | case 2: /* dynamic block */ | |
430 | state->mode = TABLE; | |
431 | break; | |
432 | case 3: | |
433 | strm->msg = (char *)"invalid block type"; | |
434 | state->mode = BAD; | |
435 | } | |
436 | DROPBITS(2); | |
437 | break; | |
438 | case STORED: | |
439 | BYTEBITS(); /* go to byte boundary */ | |
440 | NEEDBITS(32); | |
441 | if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { | |
442 | strm->msg = (char *)"invalid stored block lengths"; | |
443 | state->mode = BAD; | |
444 | break; | |
445 | } | |
446 | state->length = (unsigned)hold & 0xffff; | |
447 | INITBITS(); | |
448 | state->mode = COPY; | |
36f9ff9e | 449 | fallthrough; |
4f3865fb RP |
450 | case COPY: |
451 | copy = state->length; | |
452 | if (copy) { | |
453 | if (copy > have) copy = have; | |
454 | if (copy > left) copy = left; | |
455 | if (copy == 0) goto inf_leave; | |
456 | memcpy(put, next, copy); | |
457 | have -= copy; | |
458 | next += copy; | |
459 | left -= copy; | |
460 | put += copy; | |
461 | state->length -= copy; | |
462 | break; | |
463 | } | |
464 | state->mode = TYPE; | |
465 | break; | |
466 | case TABLE: | |
467 | NEEDBITS(14); | |
468 | state->nlen = BITS(5) + 257; | |
469 | DROPBITS(5); | |
470 | state->ndist = BITS(5) + 1; | |
471 | DROPBITS(5); | |
472 | state->ncode = BITS(4) + 4; | |
473 | DROPBITS(4); | |
474 | #ifndef PKZIP_BUG_WORKAROUND | |
475 | if (state->nlen > 286 || state->ndist > 30) { | |
476 | strm->msg = (char *)"too many length or distance symbols"; | |
477 | state->mode = BAD; | |
478 | break; | |
479 | } | |
480 | #endif | |
481 | state->have = 0; | |
482 | state->mode = LENLENS; | |
36f9ff9e | 483 | fallthrough; |
4f3865fb RP |
484 | case LENLENS: |
485 | while (state->have < state->ncode) { | |
486 | NEEDBITS(3); | |
487 | state->lens[order[state->have++]] = (unsigned short)BITS(3); | |
488 | DROPBITS(3); | |
489 | } | |
490 | while (state->have < 19) | |
491 | state->lens[order[state->have++]] = 0; | |
492 | state->next = state->codes; | |
493 | state->lencode = (code const *)(state->next); | |
494 | state->lenbits = 7; | |
495 | ret = zlib_inflate_table(CODES, state->lens, 19, &(state->next), | |
496 | &(state->lenbits), state->work); | |
497 | if (ret) { | |
498 | strm->msg = (char *)"invalid code lengths set"; | |
499 | state->mode = BAD; | |
500 | break; | |
501 | } | |
502 | state->have = 0; | |
503 | state->mode = CODELENS; | |
36f9ff9e | 504 | fallthrough; |
4f3865fb RP |
505 | case CODELENS: |
506 | while (state->have < state->nlen + state->ndist) { | |
507 | for (;;) { | |
508 | this = state->lencode[BITS(state->lenbits)]; | |
509 | if ((unsigned)(this.bits) <= bits) break; | |
510 | PULLBYTE(); | |
511 | } | |
512 | if (this.val < 16) { | |
513 | NEEDBITS(this.bits); | |
514 | DROPBITS(this.bits); | |
515 | state->lens[state->have++] = this.val; | |
516 | } | |
517 | else { | |
518 | if (this.val == 16) { | |
519 | NEEDBITS(this.bits + 2); | |
520 | DROPBITS(this.bits); | |
521 | if (state->have == 0) { | |
522 | strm->msg = (char *)"invalid bit length repeat"; | |
523 | state->mode = BAD; | |
524 | break; | |
525 | } | |
526 | len = state->lens[state->have - 1]; | |
527 | copy = 3 + BITS(2); | |
528 | DROPBITS(2); | |
529 | } | |
530 | else if (this.val == 17) { | |
531 | NEEDBITS(this.bits + 3); | |
532 | DROPBITS(this.bits); | |
533 | len = 0; | |
534 | copy = 3 + BITS(3); | |
535 | DROPBITS(3); | |
536 | } | |
537 | else { | |
538 | NEEDBITS(this.bits + 7); | |
539 | DROPBITS(this.bits); | |
540 | len = 0; | |
541 | copy = 11 + BITS(7); | |
542 | DROPBITS(7); | |
543 | } | |
544 | if (state->have + copy > state->nlen + state->ndist) { | |
545 | strm->msg = (char *)"invalid bit length repeat"; | |
546 | state->mode = BAD; | |
547 | break; | |
548 | } | |
549 | while (copy--) | |
550 | state->lens[state->have++] = (unsigned short)len; | |
551 | } | |
552 | } | |
553 | ||
554 | /* handle error breaks in while */ | |
555 | if (state->mode == BAD) break; | |
556 | ||
557 | /* build code tables */ | |
558 | state->next = state->codes; | |
559 | state->lencode = (code const *)(state->next); | |
560 | state->lenbits = 9; | |
561 | ret = zlib_inflate_table(LENS, state->lens, state->nlen, &(state->next), | |
562 | &(state->lenbits), state->work); | |
563 | if (ret) { | |
564 | strm->msg = (char *)"invalid literal/lengths set"; | |
565 | state->mode = BAD; | |
566 | break; | |
567 | } | |
568 | state->distcode = (code const *)(state->next); | |
569 | state->distbits = 6; | |
570 | ret = zlib_inflate_table(DISTS, state->lens + state->nlen, state->ndist, | |
571 | &(state->next), &(state->distbits), state->work); | |
572 | if (ret) { | |
573 | strm->msg = (char *)"invalid distances set"; | |
574 | state->mode = BAD; | |
575 | break; | |
576 | } | |
577 | state->mode = LEN; | |
36f9ff9e | 578 | fallthrough; |
4f3865fb RP |
579 | case LEN: |
580 | if (have >= 6 && left >= 258) { | |
581 | RESTORE(); | |
582 | inflate_fast(strm, out); | |
583 | LOAD(); | |
584 | break; | |
585 | } | |
586 | for (;;) { | |
587 | this = state->lencode[BITS(state->lenbits)]; | |
588 | if ((unsigned)(this.bits) <= bits) break; | |
589 | PULLBYTE(); | |
590 | } | |
591 | if (this.op && (this.op & 0xf0) == 0) { | |
592 | last = this; | |
593 | for (;;) { | |
594 | this = state->lencode[last.val + | |
595 | (BITS(last.bits + last.op) >> last.bits)]; | |
596 | if ((unsigned)(last.bits + this.bits) <= bits) break; | |
597 | PULLBYTE(); | |
598 | } | |
599 | DROPBITS(last.bits); | |
600 | } | |
601 | DROPBITS(this.bits); | |
602 | state->length = (unsigned)this.val; | |
603 | if ((int)(this.op) == 0) { | |
604 | state->mode = LIT; | |
605 | break; | |
606 | } | |
607 | if (this.op & 32) { | |
608 | state->mode = TYPE; | |
609 | break; | |
610 | } | |
611 | if (this.op & 64) { | |
612 | strm->msg = (char *)"invalid literal/length code"; | |
613 | state->mode = BAD; | |
614 | break; | |
615 | } | |
616 | state->extra = (unsigned)(this.op) & 15; | |
617 | state->mode = LENEXT; | |
36f9ff9e | 618 | fallthrough; |
4f3865fb RP |
619 | case LENEXT: |
620 | if (state->extra) { | |
621 | NEEDBITS(state->extra); | |
622 | state->length += BITS(state->extra); | |
623 | DROPBITS(state->extra); | |
624 | } | |
625 | state->mode = DIST; | |
36f9ff9e | 626 | fallthrough; |
4f3865fb RP |
627 | case DIST: |
628 | for (;;) { | |
629 | this = state->distcode[BITS(state->distbits)]; | |
630 | if ((unsigned)(this.bits) <= bits) break; | |
631 | PULLBYTE(); | |
632 | } | |
633 | if ((this.op & 0xf0) == 0) { | |
634 | last = this; | |
635 | for (;;) { | |
636 | this = state->distcode[last.val + | |
637 | (BITS(last.bits + last.op) >> last.bits)]; | |
638 | if ((unsigned)(last.bits + this.bits) <= bits) break; | |
639 | PULLBYTE(); | |
640 | } | |
641 | DROPBITS(last.bits); | |
642 | } | |
643 | DROPBITS(this.bits); | |
644 | if (this.op & 64) { | |
645 | strm->msg = (char *)"invalid distance code"; | |
646 | state->mode = BAD; | |
647 | break; | |
648 | } | |
649 | state->offset = (unsigned)this.val; | |
650 | state->extra = (unsigned)(this.op) & 15; | |
651 | state->mode = DISTEXT; | |
36f9ff9e | 652 | fallthrough; |
4f3865fb RP |
653 | case DISTEXT: |
654 | if (state->extra) { | |
655 | NEEDBITS(state->extra); | |
656 | state->offset += BITS(state->extra); | |
657 | DROPBITS(state->extra); | |
658 | } | |
659 | #ifdef INFLATE_STRICT | |
660 | if (state->offset > state->dmax) { | |
661 | strm->msg = (char *)"invalid distance too far back"; | |
662 | state->mode = BAD; | |
663 | break; | |
664 | } | |
665 | #endif | |
666 | if (state->offset > state->whave + out - left) { | |
667 | strm->msg = (char *)"invalid distance too far back"; | |
668 | state->mode = BAD; | |
669 | break; | |
670 | } | |
671 | state->mode = MATCH; | |
36f9ff9e | 672 | fallthrough; |
4f3865fb RP |
673 | case MATCH: |
674 | if (left == 0) goto inf_leave; | |
675 | copy = out - left; | |
676 | if (state->offset > copy) { /* copy from window */ | |
677 | copy = state->offset - copy; | |
678 | if (copy > state->write) { | |
679 | copy -= state->write; | |
680 | from = state->window + (state->wsize - copy); | |
681 | } | |
682 | else | |
683 | from = state->window + (state->write - copy); | |
684 | if (copy > state->length) copy = state->length; | |
685 | } | |
686 | else { /* copy from output */ | |
687 | from = put - state->offset; | |
688 | copy = state->length; | |
689 | } | |
690 | if (copy > left) copy = left; | |
691 | left -= copy; | |
692 | state->length -= copy; | |
693 | do { | |
694 | *put++ = *from++; | |
695 | } while (--copy); | |
696 | if (state->length == 0) state->mode = LEN; | |
697 | break; | |
698 | case LIT: | |
699 | if (left == 0) goto inf_leave; | |
700 | *put++ = (unsigned char)(state->length); | |
701 | left--; | |
702 | state->mode = LEN; | |
703 | break; | |
704 | case CHECK: | |
705 | if (state->wrap) { | |
706 | NEEDBITS(32); | |
707 | out -= left; | |
708 | strm->total_out += out; | |
709 | state->total += out; | |
12619610 | 710 | if (INFLATE_NEED_CHECKSUM(strm) && out) |
4f3865fb RP |
711 | strm->adler = state->check = |
712 | UPDATE(state->check, put - out, out); | |
713 | out = left; | |
714 | if (( | |
715 | REVERSE(hold)) != state->check) { | |
716 | strm->msg = (char *)"incorrect data check"; | |
717 | state->mode = BAD; | |
718 | break; | |
719 | } | |
720 | INITBITS(); | |
721 | } | |
722 | state->mode = DONE; | |
36f9ff9e | 723 | fallthrough; |
4f3865fb RP |
724 | case DONE: |
725 | ret = Z_STREAM_END; | |
726 | goto inf_leave; | |
727 | case BAD: | |
728 | ret = Z_DATA_ERROR; | |
729 | goto inf_leave; | |
730 | case MEM: | |
731 | return Z_MEM_ERROR; | |
732 | case SYNC: | |
733 | default: | |
734 | return Z_STREAM_ERROR; | |
735 | } | |
736 | ||
737 | /* | |
738 | Return from inflate(), updating the total counts and the check value. | |
739 | If there was no progress during the inflate() call, return a buffer | |
740 | error. Call zlib_updatewindow() to create and/or update the window state. | |
741 | */ | |
742 | inf_leave: | |
743 | RESTORE(); | |
12619610 MZ |
744 | if (INFLATE_NEED_UPDATEWINDOW(strm) && |
745 | (state->wsize || (state->mode < CHECK && out != strm->avail_out))) | |
4f3865fb RP |
746 | zlib_updatewindow(strm, out); |
747 | ||
748 | in -= strm->avail_in; | |
749 | out -= strm->avail_out; | |
750 | strm->total_in += in; | |
751 | strm->total_out += out; | |
752 | state->total += out; | |
12619610 | 753 | if (INFLATE_NEED_CHECKSUM(strm) && state->wrap && out) |
4f3865fb RP |
754 | strm->adler = state->check = |
755 | UPDATE(state->check, strm->next_out - out, out); | |
756 | ||
757 | strm->data_type = state->bits + (state->last ? 64 : 0) + | |
758 | (state->mode == TYPE ? 128 : 0); | |
4f3865fb RP |
759 | |
760 | if (flush == Z_PACKET_FLUSH && ret == Z_OK && | |
f0ac6758 | 761 | strm->avail_out != 0 && strm->avail_in == 0) |
4f3865fb | 762 | return zlib_inflateSyncPacket(strm); |
f0ac6758 RP |
763 | |
764 | if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK) | |
765 | ret = Z_BUF_ERROR; | |
766 | ||
4f3865fb RP |
767 | return ret; |
768 | } | |
769 | ||
770 | int zlib_inflateEnd(z_streamp strm) | |
771 | { | |
772 | if (strm == NULL || strm->state == NULL) | |
773 | return Z_STREAM_ERROR; | |
1da177e4 LT |
774 | return Z_OK; |
775 | } | |
776 | ||
4f3865fb RP |
777 | /* |
778 | * This subroutine adds the data at next_in/avail_in to the output history | |
779 | * without performing any output. The output buffer must be "caught up"; | |
780 | * i.e. no pending output but this should always be the case. The state must | |
781 | * be waiting on the start of a block (i.e. mode == TYPE or HEAD). On exit, | |
782 | * the output will also be caught up, and the checksum will have been updated | |
783 | * if need be. | |
784 | */ | |
785 | int zlib_inflateIncomp(z_stream *z) | |
1da177e4 | 786 | { |
4f3865fb RP |
787 | struct inflate_state *state = (struct inflate_state *)z->state; |
788 | Byte *saved_no = z->next_out; | |
789 | uInt saved_ao = z->avail_out; | |
790 | ||
791 | if (state->mode != TYPE && state->mode != HEAD) | |
792 | return Z_DATA_ERROR; | |
793 | ||
794 | /* Setup some variables to allow misuse of updateWindow */ | |
795 | z->avail_out = 0; | |
8336793b | 796 | z->next_out = (unsigned char*)z->next_in + z->avail_in; |
4f3865fb RP |
797 | |
798 | zlib_updatewindow(z, z->avail_in); | |
799 | ||
800 | /* Restore saved variables */ | |
801 | z->avail_out = saved_ao; | |
802 | z->next_out = saved_no; | |
803 | ||
804 | z->adler = state->check = | |
805 | UPDATE(state->check, z->next_in, z->avail_in); | |
806 | ||
807 | z->total_out += z->avail_in; | |
808 | z->total_in += z->avail_in; | |
809 | z->next_in += z->avail_in; | |
810 | state->total += z->avail_in; | |
811 | z->avail_in = 0; | |
812 | ||
813 | return Z_OK; | |
1da177e4 | 814 | } |