| 1 |
/* infback.c -- inflate using a call-back interface |
| 2 |
* Copyright (C) 1995-2011 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 = 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 |
} |
