1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/security/nss/lib/zlib/inflate.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,1480 @@
1.4 +/* inflate.c -- zlib decompression
1.5 + * Copyright (C) 1995-2010 Mark Adler
1.6 + * For conditions of distribution and use, see copyright notice in zlib.h
1.7 + */
1.8 +
1.9 +/*
1.10 + * Change history:
1.11 + *
1.12 + * 1.2.beta0 24 Nov 2002
1.13 + * - First version -- complete rewrite of inflate to simplify code, avoid
1.14 + * creation of window when not needed, minimize use of window when it is
1.15 + * needed, make inffast.c even faster, implement gzip decoding, and to
1.16 + * improve code readability and style over the previous zlib inflate code
1.17 + *
1.18 + * 1.2.beta1 25 Nov 2002
1.19 + * - Use pointers for available input and output checking in inffast.c
1.20 + * - Remove input and output counters in inffast.c
1.21 + * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
1.22 + * - Remove unnecessary second byte pull from length extra in inffast.c
1.23 + * - Unroll direct copy to three copies per loop in inffast.c
1.24 + *
1.25 + * 1.2.beta2 4 Dec 2002
1.26 + * - Change external routine names to reduce potential conflicts
1.27 + * - Correct filename to inffixed.h for fixed tables in inflate.c
1.28 + * - Make hbuf[] unsigned char to match parameter type in inflate.c
1.29 + * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
1.30 + * to avoid negation problem on Alphas (64 bit) in inflate.c
1.31 + *
1.32 + * 1.2.beta3 22 Dec 2002
1.33 + * - Add comments on state->bits assertion in inffast.c
1.34 + * - Add comments on op field in inftrees.h
1.35 + * - Fix bug in reuse of allocated window after inflateReset()
1.36 + * - Remove bit fields--back to byte structure for speed
1.37 + * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
1.38 + * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
1.39 + * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
1.40 + * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
1.41 + * - Use local copies of stream next and avail values, as well as local bit
1.42 + * buffer and bit count in inflate()--for speed when inflate_fast() not used
1.43 + *
1.44 + * 1.2.beta4 1 Jan 2003
1.45 + * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
1.46 + * - Move a comment on output buffer sizes from inffast.c to inflate.c
1.47 + * - Add comments in inffast.c to introduce the inflate_fast() routine
1.48 + * - Rearrange window copies in inflate_fast() for speed and simplification
1.49 + * - Unroll last copy for window match in inflate_fast()
1.50 + * - Use local copies of window variables in inflate_fast() for speed
1.51 + * - Pull out common wnext == 0 case for speed in inflate_fast()
1.52 + * - Make op and len in inflate_fast() unsigned for consistency
1.53 + * - Add FAR to lcode and dcode declarations in inflate_fast()
1.54 + * - Simplified bad distance check in inflate_fast()
1.55 + * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
1.56 + * source file infback.c to provide a call-back interface to inflate for
1.57 + * programs like gzip and unzip -- uses window as output buffer to avoid
1.58 + * window copying
1.59 + *
1.60 + * 1.2.beta5 1 Jan 2003
1.61 + * - Improved inflateBack() interface to allow the caller to provide initial
1.62 + * input in strm.
1.63 + * - Fixed stored blocks bug in inflateBack()
1.64 + *
1.65 + * 1.2.beta6 4 Jan 2003
1.66 + * - Added comments in inffast.c on effectiveness of POSTINC
1.67 + * - Typecasting all around to reduce compiler warnings
1.68 + * - Changed loops from while (1) or do {} while (1) to for (;;), again to
1.69 + * make compilers happy
1.70 + * - Changed type of window in inflateBackInit() to unsigned char *
1.71 + *
1.72 + * 1.2.beta7 27 Jan 2003
1.73 + * - Changed many types to unsigned or unsigned short to avoid warnings
1.74 + * - Added inflateCopy() function
1.75 + *
1.76 + * 1.2.0 9 Mar 2003
1.77 + * - Changed inflateBack() interface to provide separate opaque descriptors
1.78 + * for the in() and out() functions
1.79 + * - Changed inflateBack() argument and in_func typedef to swap the length
1.80 + * and buffer address return values for the input function
1.81 + * - Check next_in and next_out for Z_NULL on entry to inflate()
1.82 + *
1.83 + * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
1.84 + */
1.85 +
1.86 +#include "zutil.h"
1.87 +#include "inftrees.h"
1.88 +#include "inflate.h"
1.89 +#include "inffast.h"
1.90 +
1.91 +#ifdef MAKEFIXED
1.92 +# ifndef BUILDFIXED
1.93 +# define BUILDFIXED
1.94 +# endif
1.95 +#endif
1.96 +
1.97 +/* function prototypes */
1.98 +local void fixedtables OF((struct inflate_state FAR *state));
1.99 +local int updatewindow OF((z_streamp strm, unsigned out));
1.100 +#ifdef BUILDFIXED
1.101 + void makefixed OF((void));
1.102 +#endif
1.103 +local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf,
1.104 + unsigned len));
1.105 +
1.106 +int ZEXPORT inflateReset(strm)
1.107 +z_streamp strm;
1.108 +{
1.109 + struct inflate_state FAR *state;
1.110 +
1.111 + if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1.112 + state = (struct inflate_state FAR *)strm->state;
1.113 + strm->total_in = strm->total_out = state->total = 0;
1.114 + strm->msg = Z_NULL;
1.115 + strm->adler = 1; /* to support ill-conceived Java test suite */
1.116 + state->mode = HEAD;
1.117 + state->last = 0;
1.118 + state->havedict = 0;
1.119 + state->dmax = 32768U;
1.120 + state->head = Z_NULL;
1.121 + state->wsize = 0;
1.122 + state->whave = 0;
1.123 + state->wnext = 0;
1.124 + state->hold = 0;
1.125 + state->bits = 0;
1.126 + state->lencode = state->distcode = state->next = state->codes;
1.127 + state->sane = 1;
1.128 + state->back = -1;
1.129 + Tracev((stderr, "inflate: reset\n"));
1.130 + return Z_OK;
1.131 +}
1.132 +
1.133 +int ZEXPORT inflateReset2(strm, windowBits)
1.134 +z_streamp strm;
1.135 +int windowBits;
1.136 +{
1.137 + int wrap;
1.138 + struct inflate_state FAR *state;
1.139 +
1.140 + /* get the state */
1.141 + if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1.142 + state = (struct inflate_state FAR *)strm->state;
1.143 +
1.144 + /* extract wrap request from windowBits parameter */
1.145 + if (windowBits < 0) {
1.146 + wrap = 0;
1.147 + windowBits = -windowBits;
1.148 + }
1.149 + else {
1.150 + wrap = (windowBits >> 4) + 1;
1.151 +#ifdef GUNZIP
1.152 + if (windowBits < 48)
1.153 + windowBits &= 15;
1.154 +#endif
1.155 + }
1.156 +
1.157 + /* set number of window bits, free window if different */
1.158 + if (windowBits && (windowBits < 8 || windowBits > 15))
1.159 + return Z_STREAM_ERROR;
1.160 + if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
1.161 + ZFREE(strm, state->window);
1.162 + state->window = Z_NULL;
1.163 + }
1.164 +
1.165 + /* update state and reset the rest of it */
1.166 + state->wrap = wrap;
1.167 + state->wbits = (unsigned)windowBits;
1.168 + return inflateReset(strm);
1.169 +}
1.170 +
1.171 +int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
1.172 +z_streamp strm;
1.173 +int windowBits;
1.174 +const char *version;
1.175 +int stream_size;
1.176 +{
1.177 + int ret;
1.178 + struct inflate_state FAR *state;
1.179 +
1.180 + if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
1.181 + stream_size != (int)(sizeof(z_stream)))
1.182 + return Z_VERSION_ERROR;
1.183 + if (strm == Z_NULL) return Z_STREAM_ERROR;
1.184 + strm->msg = Z_NULL; /* in case we return an error */
1.185 + if (strm->zalloc == (alloc_func)0) {
1.186 + strm->zalloc = zcalloc;
1.187 + strm->opaque = (voidpf)0;
1.188 + }
1.189 + if (strm->zfree == (free_func)0) strm->zfree = zcfree;
1.190 + state = (struct inflate_state FAR *)
1.191 + ZALLOC(strm, 1, sizeof(struct inflate_state));
1.192 + if (state == Z_NULL) return Z_MEM_ERROR;
1.193 + Tracev((stderr, "inflate: allocated\n"));
1.194 + strm->state = (struct internal_state FAR *)state;
1.195 + state->window = Z_NULL;
1.196 + ret = inflateReset2(strm, windowBits);
1.197 + if (ret != Z_OK) {
1.198 + ZFREE(strm, state);
1.199 + strm->state = Z_NULL;
1.200 + }
1.201 + return ret;
1.202 +}
1.203 +
1.204 +int ZEXPORT inflateInit_(strm, version, stream_size)
1.205 +z_streamp strm;
1.206 +const char *version;
1.207 +int stream_size;
1.208 +{
1.209 + return inflateInit2_(strm, DEF_WBITS, version, stream_size);
1.210 +}
1.211 +
1.212 +int ZEXPORT inflatePrime(strm, bits, value)
1.213 +z_streamp strm;
1.214 +int bits;
1.215 +int value;
1.216 +{
1.217 + struct inflate_state FAR *state;
1.218 +
1.219 + if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1.220 + state = (struct inflate_state FAR *)strm->state;
1.221 + if (bits < 0) {
1.222 + state->hold = 0;
1.223 + state->bits = 0;
1.224 + return Z_OK;
1.225 + }
1.226 + if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
1.227 + value &= (1L << bits) - 1;
1.228 + state->hold += value << state->bits;
1.229 + state->bits += bits;
1.230 + return Z_OK;
1.231 +}
1.232 +
1.233 +/*
1.234 + Return state with length and distance decoding tables and index sizes set to
1.235 + fixed code decoding. Normally this returns fixed tables from inffixed.h.
1.236 + If BUILDFIXED is defined, then instead this routine builds the tables the
1.237 + first time it's called, and returns those tables the first time and
1.238 + thereafter. This reduces the size of the code by about 2K bytes, in
1.239 + exchange for a little execution time. However, BUILDFIXED should not be
1.240 + used for threaded applications, since the rewriting of the tables and virgin
1.241 + may not be thread-safe.
1.242 + */
1.243 +local void fixedtables(state)
1.244 +struct inflate_state FAR *state;
1.245 +{
1.246 +#ifdef BUILDFIXED
1.247 + static int virgin = 1;
1.248 + static code *lenfix, *distfix;
1.249 + static code fixed[544];
1.250 +
1.251 + /* build fixed huffman tables if first call (may not be thread safe) */
1.252 + if (virgin) {
1.253 + unsigned sym, bits;
1.254 + static code *next;
1.255 +
1.256 + /* literal/length table */
1.257 + sym = 0;
1.258 + while (sym < 144) state->lens[sym++] = 8;
1.259 + while (sym < 256) state->lens[sym++] = 9;
1.260 + while (sym < 280) state->lens[sym++] = 7;
1.261 + while (sym < 288) state->lens[sym++] = 8;
1.262 + next = fixed;
1.263 + lenfix = next;
1.264 + bits = 9;
1.265 + inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
1.266 +
1.267 + /* distance table */
1.268 + sym = 0;
1.269 + while (sym < 32) state->lens[sym++] = 5;
1.270 + distfix = next;
1.271 + bits = 5;
1.272 + inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
1.273 +
1.274 + /* do this just once */
1.275 + virgin = 0;
1.276 + }
1.277 +#else /* !BUILDFIXED */
1.278 +# include "inffixed.h"
1.279 +#endif /* BUILDFIXED */
1.280 + state->lencode = lenfix;
1.281 + state->lenbits = 9;
1.282 + state->distcode = distfix;
1.283 + state->distbits = 5;
1.284 +}
1.285 +
1.286 +#ifdef MAKEFIXED
1.287 +#include <stdio.h>
1.288 +
1.289 +/*
1.290 + Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also
1.291 + defines BUILDFIXED, so the tables are built on the fly. makefixed() writes
1.292 + those tables to stdout, which would be piped to inffixed.h. A small program
1.293 + can simply call makefixed to do this:
1.294 +
1.295 + void makefixed(void);
1.296 +
1.297 + int main(void)
1.298 + {
1.299 + makefixed();
1.300 + return 0;
1.301 + }
1.302 +
1.303 + Then that can be linked with zlib built with MAKEFIXED defined and run:
1.304 +
1.305 + a.out > inffixed.h
1.306 + */
1.307 +void makefixed()
1.308 +{
1.309 + unsigned low, size;
1.310 + struct inflate_state state;
1.311 +
1.312 + fixedtables(&state);
1.313 + puts(" /* inffixed.h -- table for decoding fixed codes");
1.314 + puts(" * Generated automatically by makefixed().");
1.315 + puts(" */");
1.316 + puts("");
1.317 + puts(" /* WARNING: this file should *not* be used by applications.");
1.318 + puts(" It is part of the implementation of this library and is");
1.319 + puts(" subject to change. Applications should only use zlib.h.");
1.320 + puts(" */");
1.321 + puts("");
1.322 + size = 1U << 9;
1.323 + printf(" static const code lenfix[%u] = {", size);
1.324 + low = 0;
1.325 + for (;;) {
1.326 + if ((low % 7) == 0) printf("\n ");
1.327 + printf("{%u,%u,%d}", state.lencode[low].op, state.lencode[low].bits,
1.328 + state.lencode[low].val);
1.329 + if (++low == size) break;
1.330 + putchar(',');
1.331 + }
1.332 + puts("\n };");
1.333 + size = 1U << 5;
1.334 + printf("\n static const code distfix[%u] = {", size);
1.335 + low = 0;
1.336 + for (;;) {
1.337 + if ((low % 6) == 0) printf("\n ");
1.338 + printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
1.339 + state.distcode[low].val);
1.340 + if (++low == size) break;
1.341 + putchar(',');
1.342 + }
1.343 + puts("\n };");
1.344 +}
1.345 +#endif /* MAKEFIXED */
1.346 +
1.347 +/*
1.348 + Update the window with the last wsize (normally 32K) bytes written before
1.349 + returning. If window does not exist yet, create it. This is only called
1.350 + when a window is already in use, or when output has been written during this
1.351 + inflate call, but the end of the deflate stream has not been reached yet.
1.352 + It is also called to create a window for dictionary data when a dictionary
1.353 + is loaded.
1.354 +
1.355 + Providing output buffers larger than 32K to inflate() should provide a speed
1.356 + advantage, since only the last 32K of output is copied to the sliding window
1.357 + upon return from inflate(), and since all distances after the first 32K of
1.358 + output will fall in the output data, making match copies simpler and faster.
1.359 + The advantage may be dependent on the size of the processor's data caches.
1.360 + */
1.361 +local int updatewindow(strm, out)
1.362 +z_streamp strm;
1.363 +unsigned out;
1.364 +{
1.365 + struct inflate_state FAR *state;
1.366 + unsigned copy, dist;
1.367 +
1.368 + state = (struct inflate_state FAR *)strm->state;
1.369 +
1.370 + /* if it hasn't been done already, allocate space for the window */
1.371 + if (state->window == Z_NULL) {
1.372 + state->window = (unsigned char FAR *)
1.373 + ZALLOC(strm, 1U << state->wbits,
1.374 + sizeof(unsigned char));
1.375 + if (state->window == Z_NULL) return 1;
1.376 + }
1.377 +
1.378 + /* if window not in use yet, initialize */
1.379 + if (state->wsize == 0) {
1.380 + state->wsize = 1U << state->wbits;
1.381 + state->wnext = 0;
1.382 + state->whave = 0;
1.383 + }
1.384 +
1.385 + /* copy state->wsize or less output bytes into the circular window */
1.386 + copy = out - strm->avail_out;
1.387 + if (copy >= state->wsize) {
1.388 + zmemcpy(state->window, strm->next_out - state->wsize, state->wsize);
1.389 + state->wnext = 0;
1.390 + state->whave = state->wsize;
1.391 + }
1.392 + else {
1.393 + dist = state->wsize - state->wnext;
1.394 + if (dist > copy) dist = copy;
1.395 + zmemcpy(state->window + state->wnext, strm->next_out - copy, dist);
1.396 + copy -= dist;
1.397 + if (copy) {
1.398 + zmemcpy(state->window, strm->next_out - copy, copy);
1.399 + state->wnext = copy;
1.400 + state->whave = state->wsize;
1.401 + }
1.402 + else {
1.403 + state->wnext += dist;
1.404 + if (state->wnext == state->wsize) state->wnext = 0;
1.405 + if (state->whave < state->wsize) state->whave += dist;
1.406 + }
1.407 + }
1.408 + return 0;
1.409 +}
1.410 +
1.411 +/* Macros for inflate(): */
1.412 +
1.413 +/* check function to use adler32() for zlib or crc32() for gzip */
1.414 +#ifdef GUNZIP
1.415 +# define UPDATE(check, buf, len) \
1.416 + (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
1.417 +#else
1.418 +# define UPDATE(check, buf, len) adler32(check, buf, len)
1.419 +#endif
1.420 +
1.421 +/* check macros for header crc */
1.422 +#ifdef GUNZIP
1.423 +# define CRC2(check, word) \
1.424 + do { \
1.425 + hbuf[0] = (unsigned char)(word); \
1.426 + hbuf[1] = (unsigned char)((word) >> 8); \
1.427 + check = crc32(check, hbuf, 2); \
1.428 + } while (0)
1.429 +
1.430 +# define CRC4(check, word) \
1.431 + do { \
1.432 + hbuf[0] = (unsigned char)(word); \
1.433 + hbuf[1] = (unsigned char)((word) >> 8); \
1.434 + hbuf[2] = (unsigned char)((word) >> 16); \
1.435 + hbuf[3] = (unsigned char)((word) >> 24); \
1.436 + check = crc32(check, hbuf, 4); \
1.437 + } while (0)
1.438 +#endif
1.439 +
1.440 +/* Load registers with state in inflate() for speed */
1.441 +#define LOAD() \
1.442 + do { \
1.443 + put = strm->next_out; \
1.444 + left = strm->avail_out; \
1.445 + next = strm->next_in; \
1.446 + have = strm->avail_in; \
1.447 + hold = state->hold; \
1.448 + bits = state->bits; \
1.449 + } while (0)
1.450 +
1.451 +/* Restore state from registers in inflate() */
1.452 +#define RESTORE() \
1.453 + do { \
1.454 + strm->next_out = put; \
1.455 + strm->avail_out = left; \
1.456 + strm->next_in = next; \
1.457 + strm->avail_in = have; \
1.458 + state->hold = hold; \
1.459 + state->bits = bits; \
1.460 + } while (0)
1.461 +
1.462 +/* Clear the input bit accumulator */
1.463 +#define INITBITS() \
1.464 + do { \
1.465 + hold = 0; \
1.466 + bits = 0; \
1.467 + } while (0)
1.468 +
1.469 +/* Get a byte of input into the bit accumulator, or return from inflate()
1.470 + if there is no input available. */
1.471 +#define PULLBYTE() \
1.472 + do { \
1.473 + if (have == 0) goto inf_leave; \
1.474 + have--; \
1.475 + hold += (unsigned long)(*next++) << bits; \
1.476 + bits += 8; \
1.477 + } while (0)
1.478 +
1.479 +/* Assure that there are at least n bits in the bit accumulator. If there is
1.480 + not enough available input to do that, then return from inflate(). */
1.481 +#define NEEDBITS(n) \
1.482 + do { \
1.483 + while (bits < (unsigned)(n)) \
1.484 + PULLBYTE(); \
1.485 + } while (0)
1.486 +
1.487 +/* Return the low n bits of the bit accumulator (n < 16) */
1.488 +#define BITS(n) \
1.489 + ((unsigned)hold & ((1U << (n)) - 1))
1.490 +
1.491 +/* Remove n bits from the bit accumulator */
1.492 +#define DROPBITS(n) \
1.493 + do { \
1.494 + hold >>= (n); \
1.495 + bits -= (unsigned)(n); \
1.496 + } while (0)
1.497 +
1.498 +/* Remove zero to seven bits as needed to go to a byte boundary */
1.499 +#define BYTEBITS() \
1.500 + do { \
1.501 + hold >>= bits & 7; \
1.502 + bits -= bits & 7; \
1.503 + } while (0)
1.504 +
1.505 +/* Reverse the bytes in a 32-bit value */
1.506 +#define REVERSE(q) \
1.507 + ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
1.508 + (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
1.509 +
1.510 +/*
1.511 + inflate() uses a state machine to process as much input data and generate as
1.512 + much output data as possible before returning. The state machine is
1.513 + structured roughly as follows:
1.514 +
1.515 + for (;;) switch (state) {
1.516 + ...
1.517 + case STATEn:
1.518 + if (not enough input data or output space to make progress)
1.519 + return;
1.520 + ... make progress ...
1.521 + state = STATEm;
1.522 + break;
1.523 + ...
1.524 + }
1.525 +
1.526 + so when inflate() is called again, the same case is attempted again, and
1.527 + if the appropriate resources are provided, the machine proceeds to the
1.528 + next state. The NEEDBITS() macro is usually the way the state evaluates
1.529 + whether it can proceed or should return. NEEDBITS() does the return if
1.530 + the requested bits are not available. The typical use of the BITS macros
1.531 + is:
1.532 +
1.533 + NEEDBITS(n);
1.534 + ... do something with BITS(n) ...
1.535 + DROPBITS(n);
1.536 +
1.537 + where NEEDBITS(n) either returns from inflate() if there isn't enough
1.538 + input left to load n bits into the accumulator, or it continues. BITS(n)
1.539 + gives the low n bits in the accumulator. When done, DROPBITS(n) drops
1.540 + the low n bits off the accumulator. INITBITS() clears the accumulator
1.541 + and sets the number of available bits to zero. BYTEBITS() discards just
1.542 + enough bits to put the accumulator on a byte boundary. After BYTEBITS()
1.543 + and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
1.544 +
1.545 + NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
1.546 + if there is no input available. The decoding of variable length codes uses
1.547 + PULLBYTE() directly in order to pull just enough bytes to decode the next
1.548 + code, and no more.
1.549 +
1.550 + Some states loop until they get enough input, making sure that enough
1.551 + state information is maintained to continue the loop where it left off
1.552 + if NEEDBITS() returns in the loop. For example, want, need, and keep
1.553 + would all have to actually be part of the saved state in case NEEDBITS()
1.554 + returns:
1.555 +
1.556 + case STATEw:
1.557 + while (want < need) {
1.558 + NEEDBITS(n);
1.559 + keep[want++] = BITS(n);
1.560 + DROPBITS(n);
1.561 + }
1.562 + state = STATEx;
1.563 + case STATEx:
1.564 +
1.565 + As shown above, if the next state is also the next case, then the break
1.566 + is omitted.
1.567 +
1.568 + A state may also return if there is not enough output space available to
1.569 + complete that state. Those states are copying stored data, writing a
1.570 + literal byte, and copying a matching string.
1.571 +
1.572 + When returning, a "goto inf_leave" is used to update the total counters,
1.573 + update the check value, and determine whether any progress has been made
1.574 + during that inflate() call in order to return the proper return code.
1.575 + Progress is defined as a change in either strm->avail_in or strm->avail_out.
1.576 + When there is a window, goto inf_leave will update the window with the last
1.577 + output written. If a goto inf_leave occurs in the middle of decompression
1.578 + and there is no window currently, goto inf_leave will create one and copy
1.579 + output to the window for the next call of inflate().
1.580 +
1.581 + In this implementation, the flush parameter of inflate() only affects the
1.582 + return code (per zlib.h). inflate() always writes as much as possible to
1.583 + strm->next_out, given the space available and the provided input--the effect
1.584 + documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
1.585 + the allocation of and copying into a sliding window until necessary, which
1.586 + provides the effect documented in zlib.h for Z_FINISH when the entire input
1.587 + stream available. So the only thing the flush parameter actually does is:
1.588 + when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
1.589 + will return Z_BUF_ERROR if it has not reached the end of the stream.
1.590 + */
1.591 +
1.592 +int ZEXPORT inflate(strm, flush)
1.593 +z_streamp strm;
1.594 +int flush;
1.595 +{
1.596 + struct inflate_state FAR *state;
1.597 + unsigned char FAR *next; /* next input */
1.598 + unsigned char FAR *put; /* next output */
1.599 + unsigned have, left; /* available input and output */
1.600 + unsigned long hold; /* bit buffer */
1.601 + unsigned bits; /* bits in bit buffer */
1.602 + unsigned in, out; /* save starting available input and output */
1.603 + unsigned copy; /* number of stored or match bytes to copy */
1.604 + unsigned char FAR *from; /* where to copy match bytes from */
1.605 + code here; /* current decoding table entry */
1.606 + code last; /* parent table entry */
1.607 + unsigned len; /* length to copy for repeats, bits to drop */
1.608 + int ret; /* return code */
1.609 +#ifdef GUNZIP
1.610 + unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
1.611 +#endif
1.612 + static const unsigned short order[19] = /* permutation of code lengths */
1.613 + {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
1.614 +
1.615 + if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL ||
1.616 + (strm->next_in == Z_NULL && strm->avail_in != 0))
1.617 + return Z_STREAM_ERROR;
1.618 +
1.619 + state = (struct inflate_state FAR *)strm->state;
1.620 + if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
1.621 + LOAD();
1.622 + in = have;
1.623 + out = left;
1.624 + ret = Z_OK;
1.625 + for (;;)
1.626 + switch (state->mode) {
1.627 + case HEAD:
1.628 + if (state->wrap == 0) {
1.629 + state->mode = TYPEDO;
1.630 + break;
1.631 + }
1.632 + NEEDBITS(16);
1.633 +#ifdef GUNZIP
1.634 + if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
1.635 + state->check = crc32(0L, Z_NULL, 0);
1.636 + CRC2(state->check, hold);
1.637 + INITBITS();
1.638 + state->mode = FLAGS;
1.639 + break;
1.640 + }
1.641 + state->flags = 0; /* expect zlib header */
1.642 + if (state->head != Z_NULL)
1.643 + state->head->done = -1;
1.644 + if (!(state->wrap & 1) || /* check if zlib header allowed */
1.645 +#else
1.646 + if (
1.647 +#endif
1.648 + ((BITS(8) << 8) + (hold >> 8)) % 31) {
1.649 + strm->msg = (char *)"incorrect header check";
1.650 + state->mode = BAD;
1.651 + break;
1.652 + }
1.653 + if (BITS(4) != Z_DEFLATED) {
1.654 + strm->msg = (char *)"unknown compression method";
1.655 + state->mode = BAD;
1.656 + break;
1.657 + }
1.658 + DROPBITS(4);
1.659 + len = BITS(4) + 8;
1.660 + if (state->wbits == 0)
1.661 + state->wbits = len;
1.662 + else if (len > state->wbits) {
1.663 + strm->msg = (char *)"invalid window size";
1.664 + state->mode = BAD;
1.665 + break;
1.666 + }
1.667 + state->dmax = 1U << len;
1.668 + Tracev((stderr, "inflate: zlib header ok\n"));
1.669 + strm->adler = state->check = adler32(0L, Z_NULL, 0);
1.670 + state->mode = hold & 0x200 ? DICTID : TYPE;
1.671 + INITBITS();
1.672 + break;
1.673 +#ifdef GUNZIP
1.674 + case FLAGS:
1.675 + NEEDBITS(16);
1.676 + state->flags = (int)(hold);
1.677 + if ((state->flags & 0xff) != Z_DEFLATED) {
1.678 + strm->msg = (char *)"unknown compression method";
1.679 + state->mode = BAD;
1.680 + break;
1.681 + }
1.682 + if (state->flags & 0xe000) {
1.683 + strm->msg = (char *)"unknown header flags set";
1.684 + state->mode = BAD;
1.685 + break;
1.686 + }
1.687 + if (state->head != Z_NULL)
1.688 + state->head->text = (int)((hold >> 8) & 1);
1.689 + if (state->flags & 0x0200) CRC2(state->check, hold);
1.690 + INITBITS();
1.691 + state->mode = TIME;
1.692 + case TIME:
1.693 + NEEDBITS(32);
1.694 + if (state->head != Z_NULL)
1.695 + state->head->time = hold;
1.696 + if (state->flags & 0x0200) CRC4(state->check, hold);
1.697 + INITBITS();
1.698 + state->mode = OS;
1.699 + case OS:
1.700 + NEEDBITS(16);
1.701 + if (state->head != Z_NULL) {
1.702 + state->head->xflags = (int)(hold & 0xff);
1.703 + state->head->os = (int)(hold >> 8);
1.704 + }
1.705 + if (state->flags & 0x0200) CRC2(state->check, hold);
1.706 + INITBITS();
1.707 + state->mode = EXLEN;
1.708 + case EXLEN:
1.709 + if (state->flags & 0x0400) {
1.710 + NEEDBITS(16);
1.711 + state->length = (unsigned)(hold);
1.712 + if (state->head != Z_NULL)
1.713 + state->head->extra_len = (unsigned)hold;
1.714 + if (state->flags & 0x0200) CRC2(state->check, hold);
1.715 + INITBITS();
1.716 + }
1.717 + else if (state->head != Z_NULL)
1.718 + state->head->extra = Z_NULL;
1.719 + state->mode = EXTRA;
1.720 + case EXTRA:
1.721 + if (state->flags & 0x0400) {
1.722 + copy = state->length;
1.723 + if (copy > have) copy = have;
1.724 + if (copy) {
1.725 + if (state->head != Z_NULL &&
1.726 + state->head->extra != Z_NULL) {
1.727 + len = state->head->extra_len - state->length;
1.728 + zmemcpy(state->head->extra + len, next,
1.729 + len + copy > state->head->extra_max ?
1.730 + state->head->extra_max - len : copy);
1.731 + }
1.732 + if (state->flags & 0x0200)
1.733 + state->check = crc32(state->check, next, copy);
1.734 + have -= copy;
1.735 + next += copy;
1.736 + state->length -= copy;
1.737 + }
1.738 + if (state->length) goto inf_leave;
1.739 + }
1.740 + state->length = 0;
1.741 + state->mode = NAME;
1.742 + case NAME:
1.743 + if (state->flags & 0x0800) {
1.744 + if (have == 0) goto inf_leave;
1.745 + copy = 0;
1.746 + do {
1.747 + len = (unsigned)(next[copy++]);
1.748 + if (state->head != Z_NULL &&
1.749 + state->head->name != Z_NULL &&
1.750 + state->length < state->head->name_max)
1.751 + state->head->name[state->length++] = len;
1.752 + } while (len && copy < have);
1.753 + if (state->flags & 0x0200)
1.754 + state->check = crc32(state->check, next, copy);
1.755 + have -= copy;
1.756 + next += copy;
1.757 + if (len) goto inf_leave;
1.758 + }
1.759 + else if (state->head != Z_NULL)
1.760 + state->head->name = Z_NULL;
1.761 + state->length = 0;
1.762 + state->mode = COMMENT;
1.763 + case COMMENT:
1.764 + if (state->flags & 0x1000) {
1.765 + if (have == 0) goto inf_leave;
1.766 + copy = 0;
1.767 + do {
1.768 + len = (unsigned)(next[copy++]);
1.769 + if (state->head != Z_NULL &&
1.770 + state->head->comment != Z_NULL &&
1.771 + state->length < state->head->comm_max)
1.772 + state->head->comment[state->length++] = len;
1.773 + } while (len && copy < have);
1.774 + if (state->flags & 0x0200)
1.775 + state->check = crc32(state->check, next, copy);
1.776 + have -= copy;
1.777 + next += copy;
1.778 + if (len) goto inf_leave;
1.779 + }
1.780 + else if (state->head != Z_NULL)
1.781 + state->head->comment = Z_NULL;
1.782 + state->mode = HCRC;
1.783 + case HCRC:
1.784 + if (state->flags & 0x0200) {
1.785 + NEEDBITS(16);
1.786 + if (hold != (state->check & 0xffff)) {
1.787 + strm->msg = (char *)"header crc mismatch";
1.788 + state->mode = BAD;
1.789 + break;
1.790 + }
1.791 + INITBITS();
1.792 + }
1.793 + if (state->head != Z_NULL) {
1.794 + state->head->hcrc = (int)((state->flags >> 9) & 1);
1.795 + state->head->done = 1;
1.796 + }
1.797 + strm->adler = state->check = crc32(0L, Z_NULL, 0);
1.798 + state->mode = TYPE;
1.799 + break;
1.800 +#endif
1.801 + case DICTID:
1.802 + NEEDBITS(32);
1.803 + strm->adler = state->check = REVERSE(hold);
1.804 + INITBITS();
1.805 + state->mode = DICT;
1.806 + case DICT:
1.807 + if (state->havedict == 0) {
1.808 + RESTORE();
1.809 + return Z_NEED_DICT;
1.810 + }
1.811 + strm->adler = state->check = adler32(0L, Z_NULL, 0);
1.812 + state->mode = TYPE;
1.813 + case TYPE:
1.814 + if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
1.815 + case TYPEDO:
1.816 + if (state->last) {
1.817 + BYTEBITS();
1.818 + state->mode = CHECK;
1.819 + break;
1.820 + }
1.821 + NEEDBITS(3);
1.822 + state->last = BITS(1);
1.823 + DROPBITS(1);
1.824 + switch (BITS(2)) {
1.825 + case 0: /* stored block */
1.826 + Tracev((stderr, "inflate: stored block%s\n",
1.827 + state->last ? " (last)" : ""));
1.828 + state->mode = STORED;
1.829 + break;
1.830 + case 1: /* fixed block */
1.831 + fixedtables(state);
1.832 + Tracev((stderr, "inflate: fixed codes block%s\n",
1.833 + state->last ? " (last)" : ""));
1.834 + state->mode = LEN_; /* decode codes */
1.835 + if (flush == Z_TREES) {
1.836 + DROPBITS(2);
1.837 + goto inf_leave;
1.838 + }
1.839 + break;
1.840 + case 2: /* dynamic block */
1.841 + Tracev((stderr, "inflate: dynamic codes block%s\n",
1.842 + state->last ? " (last)" : ""));
1.843 + state->mode = TABLE;
1.844 + break;
1.845 + case 3:
1.846 + strm->msg = (char *)"invalid block type";
1.847 + state->mode = BAD;
1.848 + }
1.849 + DROPBITS(2);
1.850 + break;
1.851 + case STORED:
1.852 + BYTEBITS(); /* go to byte boundary */
1.853 + NEEDBITS(32);
1.854 + if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
1.855 + strm->msg = (char *)"invalid stored block lengths";
1.856 + state->mode = BAD;
1.857 + break;
1.858 + }
1.859 + state->length = (unsigned)hold & 0xffff;
1.860 + Tracev((stderr, "inflate: stored length %u\n",
1.861 + state->length));
1.862 + INITBITS();
1.863 + state->mode = COPY_;
1.864 + if (flush == Z_TREES) goto inf_leave;
1.865 + case COPY_:
1.866 + state->mode = COPY;
1.867 + case COPY:
1.868 + copy = state->length;
1.869 + if (copy) {
1.870 + if (copy > have) copy = have;
1.871 + if (copy > left) copy = left;
1.872 + if (copy == 0) goto inf_leave;
1.873 + zmemcpy(put, next, copy);
1.874 + have -= copy;
1.875 + next += copy;
1.876 + left -= copy;
1.877 + put += copy;
1.878 + state->length -= copy;
1.879 + break;
1.880 + }
1.881 + Tracev((stderr, "inflate: stored end\n"));
1.882 + state->mode = TYPE;
1.883 + break;
1.884 + case TABLE:
1.885 + NEEDBITS(14);
1.886 + state->nlen = BITS(5) + 257;
1.887 + DROPBITS(5);
1.888 + state->ndist = BITS(5) + 1;
1.889 + DROPBITS(5);
1.890 + state->ncode = BITS(4) + 4;
1.891 + DROPBITS(4);
1.892 +#ifndef PKZIP_BUG_WORKAROUND
1.893 + if (state->nlen > 286 || state->ndist > 30) {
1.894 + strm->msg = (char *)"too many length or distance symbols";
1.895 + state->mode = BAD;
1.896 + break;
1.897 + }
1.898 +#endif
1.899 + Tracev((stderr, "inflate: table sizes ok\n"));
1.900 + state->have = 0;
1.901 + state->mode = LENLENS;
1.902 + case LENLENS:
1.903 + while (state->have < state->ncode) {
1.904 + NEEDBITS(3);
1.905 + state->lens[order[state->have++]] = (unsigned short)BITS(3);
1.906 + DROPBITS(3);
1.907 + }
1.908 + while (state->have < 19)
1.909 + state->lens[order[state->have++]] = 0;
1.910 + state->next = state->codes;
1.911 + state->lencode = (code const FAR *)(state->next);
1.912 + state->lenbits = 7;
1.913 + ret = inflate_table(CODES, state->lens, 19, &(state->next),
1.914 + &(state->lenbits), state->work);
1.915 + if (ret) {
1.916 + strm->msg = (char *)"invalid code lengths set";
1.917 + state->mode = BAD;
1.918 + break;
1.919 + }
1.920 + Tracev((stderr, "inflate: code lengths ok\n"));
1.921 + state->have = 0;
1.922 + state->mode = CODELENS;
1.923 + case CODELENS:
1.924 + while (state->have < state->nlen + state->ndist) {
1.925 + for (;;) {
1.926 + here = state->lencode[BITS(state->lenbits)];
1.927 + if ((unsigned)(here.bits) <= bits) break;
1.928 + PULLBYTE();
1.929 + }
1.930 + if (here.val < 16) {
1.931 + NEEDBITS(here.bits);
1.932 + DROPBITS(here.bits);
1.933 + state->lens[state->have++] = here.val;
1.934 + }
1.935 + else {
1.936 + if (here.val == 16) {
1.937 + NEEDBITS(here.bits + 2);
1.938 + DROPBITS(here.bits);
1.939 + if (state->have == 0) {
1.940 + strm->msg = (char *)"invalid bit length repeat";
1.941 + state->mode = BAD;
1.942 + break;
1.943 + }
1.944 + len = state->lens[state->have - 1];
1.945 + copy = 3 + BITS(2);
1.946 + DROPBITS(2);
1.947 + }
1.948 + else if (here.val == 17) {
1.949 + NEEDBITS(here.bits + 3);
1.950 + DROPBITS(here.bits);
1.951 + len = 0;
1.952 + copy = 3 + BITS(3);
1.953 + DROPBITS(3);
1.954 + }
1.955 + else {
1.956 + NEEDBITS(here.bits + 7);
1.957 + DROPBITS(here.bits);
1.958 + len = 0;
1.959 + copy = 11 + BITS(7);
1.960 + DROPBITS(7);
1.961 + }
1.962 + if (state->have + copy > state->nlen + state->ndist) {
1.963 + strm->msg = (char *)"invalid bit length repeat";
1.964 + state->mode = BAD;
1.965 + break;
1.966 + }
1.967 + while (copy--)
1.968 + state->lens[state->have++] = (unsigned short)len;
1.969 + }
1.970 + }
1.971 +
1.972 + /* handle error breaks in while */
1.973 + if (state->mode == BAD) break;
1.974 +
1.975 + /* check for end-of-block code (better have one) */
1.976 + if (state->lens[256] == 0) {
1.977 + strm->msg = (char *)"invalid code -- missing end-of-block";
1.978 + state->mode = BAD;
1.979 + break;
1.980 + }
1.981 +
1.982 + /* build code tables -- note: do not change the lenbits or distbits
1.983 + values here (9 and 6) without reading the comments in inftrees.h
1.984 + concerning the ENOUGH constants, which depend on those values */
1.985 + state->next = state->codes;
1.986 + state->lencode = (code const FAR *)(state->next);
1.987 + state->lenbits = 9;
1.988 + ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
1.989 + &(state->lenbits), state->work);
1.990 + if (ret) {
1.991 + strm->msg = (char *)"invalid literal/lengths set";
1.992 + state->mode = BAD;
1.993 + break;
1.994 + }
1.995 + state->distcode = (code const FAR *)(state->next);
1.996 + state->distbits = 6;
1.997 + ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
1.998 + &(state->next), &(state->distbits), state->work);
1.999 + if (ret) {
1.1000 + strm->msg = (char *)"invalid distances set";
1.1001 + state->mode = BAD;
1.1002 + break;
1.1003 + }
1.1004 + Tracev((stderr, "inflate: codes ok\n"));
1.1005 + state->mode = LEN_;
1.1006 + if (flush == Z_TREES) goto inf_leave;
1.1007 + case LEN_:
1.1008 + state->mode = LEN;
1.1009 + case LEN:
1.1010 + if (have >= 6 && left >= 258) {
1.1011 + RESTORE();
1.1012 + inflate_fast(strm, out);
1.1013 + LOAD();
1.1014 + if (state->mode == TYPE)
1.1015 + state->back = -1;
1.1016 + break;
1.1017 + }
1.1018 + state->back = 0;
1.1019 + for (;;) {
1.1020 + here = state->lencode[BITS(state->lenbits)];
1.1021 + if ((unsigned)(here.bits) <= bits) break;
1.1022 + PULLBYTE();
1.1023 + }
1.1024 + if (here.op && (here.op & 0xf0) == 0) {
1.1025 + last = here;
1.1026 + for (;;) {
1.1027 + here = state->lencode[last.val +
1.1028 + (BITS(last.bits + last.op) >> last.bits)];
1.1029 + if ((unsigned)(last.bits + here.bits) <= bits) break;
1.1030 + PULLBYTE();
1.1031 + }
1.1032 + DROPBITS(last.bits);
1.1033 + state->back += last.bits;
1.1034 + }
1.1035 + DROPBITS(here.bits);
1.1036 + state->back += here.bits;
1.1037 + state->length = (unsigned)here.val;
1.1038 + if ((int)(here.op) == 0) {
1.1039 + Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
1.1040 + "inflate: literal '%c'\n" :
1.1041 + "inflate: literal 0x%02x\n", here.val));
1.1042 + state->mode = LIT;
1.1043 + break;
1.1044 + }
1.1045 + if (here.op & 32) {
1.1046 + Tracevv((stderr, "inflate: end of block\n"));
1.1047 + state->back = -1;
1.1048 + state->mode = TYPE;
1.1049 + break;
1.1050 + }
1.1051 + if (here.op & 64) {
1.1052 + strm->msg = (char *)"invalid literal/length code";
1.1053 + state->mode = BAD;
1.1054 + break;
1.1055 + }
1.1056 + state->extra = (unsigned)(here.op) & 15;
1.1057 + state->mode = LENEXT;
1.1058 + case LENEXT:
1.1059 + if (state->extra) {
1.1060 + NEEDBITS(state->extra);
1.1061 + state->length += BITS(state->extra);
1.1062 + DROPBITS(state->extra);
1.1063 + state->back += state->extra;
1.1064 + }
1.1065 + Tracevv((stderr, "inflate: length %u\n", state->length));
1.1066 + state->was = state->length;
1.1067 + state->mode = DIST;
1.1068 + case DIST:
1.1069 + for (;;) {
1.1070 + here = state->distcode[BITS(state->distbits)];
1.1071 + if ((unsigned)(here.bits) <= bits) break;
1.1072 + PULLBYTE();
1.1073 + }
1.1074 + if ((here.op & 0xf0) == 0) {
1.1075 + last = here;
1.1076 + for (;;) {
1.1077 + here = state->distcode[last.val +
1.1078 + (BITS(last.bits + last.op) >> last.bits)];
1.1079 + if ((unsigned)(last.bits + here.bits) <= bits) break;
1.1080 + PULLBYTE();
1.1081 + }
1.1082 + DROPBITS(last.bits);
1.1083 + state->back += last.bits;
1.1084 + }
1.1085 + DROPBITS(here.bits);
1.1086 + state->back += here.bits;
1.1087 + if (here.op & 64) {
1.1088 + strm->msg = (char *)"invalid distance code";
1.1089 + state->mode = BAD;
1.1090 + break;
1.1091 + }
1.1092 + state->offset = (unsigned)here.val;
1.1093 + state->extra = (unsigned)(here.op) & 15;
1.1094 + state->mode = DISTEXT;
1.1095 + case DISTEXT:
1.1096 + if (state->extra) {
1.1097 + NEEDBITS(state->extra);
1.1098 + state->offset += BITS(state->extra);
1.1099 + DROPBITS(state->extra);
1.1100 + state->back += state->extra;
1.1101 + }
1.1102 +#ifdef INFLATE_STRICT
1.1103 + if (state->offset > state->dmax) {
1.1104 + strm->msg = (char *)"invalid distance too far back";
1.1105 + state->mode = BAD;
1.1106 + break;
1.1107 + }
1.1108 +#endif
1.1109 + Tracevv((stderr, "inflate: distance %u\n", state->offset));
1.1110 + state->mode = MATCH;
1.1111 + case MATCH:
1.1112 + if (left == 0) goto inf_leave;
1.1113 + copy = out - left;
1.1114 + if (state->offset > copy) { /* copy from window */
1.1115 + copy = state->offset - copy;
1.1116 + if (copy > state->whave) {
1.1117 + if (state->sane) {
1.1118 + strm->msg = (char *)"invalid distance too far back";
1.1119 + state->mode = BAD;
1.1120 + break;
1.1121 + }
1.1122 +#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1.1123 + Trace((stderr, "inflate.c too far\n"));
1.1124 + copy -= state->whave;
1.1125 + if (copy > state->length) copy = state->length;
1.1126 + if (copy > left) copy = left;
1.1127 + left -= copy;
1.1128 + state->length -= copy;
1.1129 + do {
1.1130 + *put++ = 0;
1.1131 + } while (--copy);
1.1132 + if (state->length == 0) state->mode = LEN;
1.1133 + break;
1.1134 +#endif
1.1135 + }
1.1136 + if (copy > state->wnext) {
1.1137 + copy -= state->wnext;
1.1138 + from = state->window + (state->wsize - copy);
1.1139 + }
1.1140 + else
1.1141 + from = state->window + (state->wnext - copy);
1.1142 + if (copy > state->length) copy = state->length;
1.1143 + }
1.1144 + else { /* copy from output */
1.1145 + from = put - state->offset;
1.1146 + copy = state->length;
1.1147 + }
1.1148 + if (copy > left) copy = left;
1.1149 + left -= copy;
1.1150 + state->length -= copy;
1.1151 + do {
1.1152 + *put++ = *from++;
1.1153 + } while (--copy);
1.1154 + if (state->length == 0) state->mode = LEN;
1.1155 + break;
1.1156 + case LIT:
1.1157 + if (left == 0) goto inf_leave;
1.1158 + *put++ = (unsigned char)(state->length);
1.1159 + left--;
1.1160 + state->mode = LEN;
1.1161 + break;
1.1162 + case CHECK:
1.1163 + if (state->wrap) {
1.1164 + NEEDBITS(32);
1.1165 + out -= left;
1.1166 + strm->total_out += out;
1.1167 + state->total += out;
1.1168 + if (out)
1.1169 + strm->adler = state->check =
1.1170 + UPDATE(state->check, put - out, out);
1.1171 + out = left;
1.1172 + if ((
1.1173 +#ifdef GUNZIP
1.1174 + state->flags ? hold :
1.1175 +#endif
1.1176 + REVERSE(hold)) != state->check) {
1.1177 + strm->msg = (char *)"incorrect data check";
1.1178 + state->mode = BAD;
1.1179 + break;
1.1180 + }
1.1181 + INITBITS();
1.1182 + Tracev((stderr, "inflate: check matches trailer\n"));
1.1183 + }
1.1184 +#ifdef GUNZIP
1.1185 + state->mode = LENGTH;
1.1186 + case LENGTH:
1.1187 + if (state->wrap && state->flags) {
1.1188 + NEEDBITS(32);
1.1189 + if (hold != (state->total & 0xffffffffUL)) {
1.1190 + strm->msg = (char *)"incorrect length check";
1.1191 + state->mode = BAD;
1.1192 + break;
1.1193 + }
1.1194 + INITBITS();
1.1195 + Tracev((stderr, "inflate: length matches trailer\n"));
1.1196 + }
1.1197 +#endif
1.1198 + state->mode = DONE;
1.1199 + case DONE:
1.1200 + ret = Z_STREAM_END;
1.1201 + goto inf_leave;
1.1202 + case BAD:
1.1203 + ret = Z_DATA_ERROR;
1.1204 + goto inf_leave;
1.1205 + case MEM:
1.1206 + return Z_MEM_ERROR;
1.1207 + case SYNC:
1.1208 + default:
1.1209 + return Z_STREAM_ERROR;
1.1210 + }
1.1211 +
1.1212 + /*
1.1213 + Return from inflate(), updating the total counts and the check value.
1.1214 + If there was no progress during the inflate() call, return a buffer
1.1215 + error. Call updatewindow() to create and/or update the window state.
1.1216 + Note: a memory error from inflate() is non-recoverable.
1.1217 + */
1.1218 + inf_leave:
1.1219 + RESTORE();
1.1220 + if (state->wsize || (state->mode < CHECK && out != strm->avail_out))
1.1221 + if (updatewindow(strm, out)) {
1.1222 + state->mode = MEM;
1.1223 + return Z_MEM_ERROR;
1.1224 + }
1.1225 + in -= strm->avail_in;
1.1226 + out -= strm->avail_out;
1.1227 + strm->total_in += in;
1.1228 + strm->total_out += out;
1.1229 + state->total += out;
1.1230 + if (state->wrap && out)
1.1231 + strm->adler = state->check =
1.1232 + UPDATE(state->check, strm->next_out - out, out);
1.1233 + strm->data_type = state->bits + (state->last ? 64 : 0) +
1.1234 + (state->mode == TYPE ? 128 : 0) +
1.1235 + (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
1.1236 + if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
1.1237 + ret = Z_BUF_ERROR;
1.1238 + return ret;
1.1239 +}
1.1240 +
1.1241 +int ZEXPORT inflateEnd(strm)
1.1242 +z_streamp strm;
1.1243 +{
1.1244 + struct inflate_state FAR *state;
1.1245 + if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
1.1246 + return Z_STREAM_ERROR;
1.1247 + state = (struct inflate_state FAR *)strm->state;
1.1248 + if (state->window != Z_NULL) ZFREE(strm, state->window);
1.1249 + ZFREE(strm, strm->state);
1.1250 + strm->state = Z_NULL;
1.1251 + Tracev((stderr, "inflate: end\n"));
1.1252 + return Z_OK;
1.1253 +}
1.1254 +
1.1255 +int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
1.1256 +z_streamp strm;
1.1257 +const Bytef *dictionary;
1.1258 +uInt dictLength;
1.1259 +{
1.1260 + struct inflate_state FAR *state;
1.1261 + unsigned long id;
1.1262 +
1.1263 + /* check state */
1.1264 + if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1.1265 + state = (struct inflate_state FAR *)strm->state;
1.1266 + if (state->wrap != 0 && state->mode != DICT)
1.1267 + return Z_STREAM_ERROR;
1.1268 +
1.1269 + /* check for correct dictionary id */
1.1270 + if (state->mode == DICT) {
1.1271 + id = adler32(0L, Z_NULL, 0);
1.1272 + id = adler32(id, dictionary, dictLength);
1.1273 + if (id != state->check)
1.1274 + return Z_DATA_ERROR;
1.1275 + }
1.1276 +
1.1277 + /* copy dictionary to window */
1.1278 + if (updatewindow(strm, strm->avail_out)) {
1.1279 + state->mode = MEM;
1.1280 + return Z_MEM_ERROR;
1.1281 + }
1.1282 + if (dictLength > state->wsize) {
1.1283 + zmemcpy(state->window, dictionary + dictLength - state->wsize,
1.1284 + state->wsize);
1.1285 + state->whave = state->wsize;
1.1286 + }
1.1287 + else {
1.1288 + zmemcpy(state->window + state->wsize - dictLength, dictionary,
1.1289 + dictLength);
1.1290 + state->whave = dictLength;
1.1291 + }
1.1292 + state->havedict = 1;
1.1293 + Tracev((stderr, "inflate: dictionary set\n"));
1.1294 + return Z_OK;
1.1295 +}
1.1296 +
1.1297 +int ZEXPORT inflateGetHeader(strm, head)
1.1298 +z_streamp strm;
1.1299 +gz_headerp head;
1.1300 +{
1.1301 + struct inflate_state FAR *state;
1.1302 +
1.1303 + /* check state */
1.1304 + if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1.1305 + state = (struct inflate_state FAR *)strm->state;
1.1306 + if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
1.1307 +
1.1308 + /* save header structure */
1.1309 + state->head = head;
1.1310 + head->done = 0;
1.1311 + return Z_OK;
1.1312 +}
1.1313 +
1.1314 +/*
1.1315 + Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found
1.1316 + or when out of input. When called, *have is the number of pattern bytes
1.1317 + found in order so far, in 0..3. On return *have is updated to the new
1.1318 + state. If on return *have equals four, then the pattern was found and the
1.1319 + return value is how many bytes were read including the last byte of the
1.1320 + pattern. If *have is less than four, then the pattern has not been found
1.1321 + yet and the return value is len. In the latter case, syncsearch() can be
1.1322 + called again with more data and the *have state. *have is initialized to
1.1323 + zero for the first call.
1.1324 + */
1.1325 +local unsigned syncsearch(have, buf, len)
1.1326 +unsigned FAR *have;
1.1327 +unsigned char FAR *buf;
1.1328 +unsigned len;
1.1329 +{
1.1330 + unsigned got;
1.1331 + unsigned next;
1.1332 +
1.1333 + got = *have;
1.1334 + next = 0;
1.1335 + while (next < len && got < 4) {
1.1336 + if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
1.1337 + got++;
1.1338 + else if (buf[next])
1.1339 + got = 0;
1.1340 + else
1.1341 + got = 4 - got;
1.1342 + next++;
1.1343 + }
1.1344 + *have = got;
1.1345 + return next;
1.1346 +}
1.1347 +
1.1348 +int ZEXPORT inflateSync(strm)
1.1349 +z_streamp strm;
1.1350 +{
1.1351 + unsigned len; /* number of bytes to look at or looked at */
1.1352 + unsigned long in, out; /* temporary to save total_in and total_out */
1.1353 + unsigned char buf[4]; /* to restore bit buffer to byte string */
1.1354 + struct inflate_state FAR *state;
1.1355 +
1.1356 + /* check parameters */
1.1357 + if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1.1358 + state = (struct inflate_state FAR *)strm->state;
1.1359 + if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
1.1360 +
1.1361 + /* if first time, start search in bit buffer */
1.1362 + if (state->mode != SYNC) {
1.1363 + state->mode = SYNC;
1.1364 + state->hold <<= state->bits & 7;
1.1365 + state->bits -= state->bits & 7;
1.1366 + len = 0;
1.1367 + while (state->bits >= 8) {
1.1368 + buf[len++] = (unsigned char)(state->hold);
1.1369 + state->hold >>= 8;
1.1370 + state->bits -= 8;
1.1371 + }
1.1372 + state->have = 0;
1.1373 + syncsearch(&(state->have), buf, len);
1.1374 + }
1.1375 +
1.1376 + /* search available input */
1.1377 + len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
1.1378 + strm->avail_in -= len;
1.1379 + strm->next_in += len;
1.1380 + strm->total_in += len;
1.1381 +
1.1382 + /* return no joy or set up to restart inflate() on a new block */
1.1383 + if (state->have != 4) return Z_DATA_ERROR;
1.1384 + in = strm->total_in; out = strm->total_out;
1.1385 + inflateReset(strm);
1.1386 + strm->total_in = in; strm->total_out = out;
1.1387 + state->mode = TYPE;
1.1388 + return Z_OK;
1.1389 +}
1.1390 +
1.1391 +/*
1.1392 + Returns true if inflate is currently at the end of a block generated by
1.1393 + Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
1.1394 + implementation to provide an additional safety check. PPP uses
1.1395 + Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
1.1396 + block. When decompressing, PPP checks that at the end of input packet,
1.1397 + inflate is waiting for these length bytes.
1.1398 + */
1.1399 +int ZEXPORT inflateSyncPoint(strm)
1.1400 +z_streamp strm;
1.1401 +{
1.1402 + struct inflate_state FAR *state;
1.1403 +
1.1404 + if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1.1405 + state = (struct inflate_state FAR *)strm->state;
1.1406 + return state->mode == STORED && state->bits == 0;
1.1407 +}
1.1408 +
1.1409 +int ZEXPORT inflateCopy(dest, source)
1.1410 +z_streamp dest;
1.1411 +z_streamp source;
1.1412 +{
1.1413 + struct inflate_state FAR *state;
1.1414 + struct inflate_state FAR *copy;
1.1415 + unsigned char FAR *window;
1.1416 + unsigned wsize;
1.1417 +
1.1418 + /* check input */
1.1419 + if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL ||
1.1420 + source->zalloc == (alloc_func)0 || source->zfree == (free_func)0)
1.1421 + return Z_STREAM_ERROR;
1.1422 + state = (struct inflate_state FAR *)source->state;
1.1423 +
1.1424 + /* allocate space */
1.1425 + copy = (struct inflate_state FAR *)
1.1426 + ZALLOC(source, 1, sizeof(struct inflate_state));
1.1427 + if (copy == Z_NULL) return Z_MEM_ERROR;
1.1428 + window = Z_NULL;
1.1429 + if (state->window != Z_NULL) {
1.1430 + window = (unsigned char FAR *)
1.1431 + ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
1.1432 + if (window == Z_NULL) {
1.1433 + ZFREE(source, copy);
1.1434 + return Z_MEM_ERROR;
1.1435 + }
1.1436 + }
1.1437 +
1.1438 + /* copy state */
1.1439 + zmemcpy(dest, source, sizeof(z_stream));
1.1440 + zmemcpy(copy, state, sizeof(struct inflate_state));
1.1441 + if (state->lencode >= state->codes &&
1.1442 + state->lencode <= state->codes + ENOUGH - 1) {
1.1443 + copy->lencode = copy->codes + (state->lencode - state->codes);
1.1444 + copy->distcode = copy->codes + (state->distcode - state->codes);
1.1445 + }
1.1446 + copy->next = copy->codes + (state->next - state->codes);
1.1447 + if (window != Z_NULL) {
1.1448 + wsize = 1U << state->wbits;
1.1449 + zmemcpy(window, state->window, wsize);
1.1450 + }
1.1451 + copy->window = window;
1.1452 + dest->state = (struct internal_state FAR *)copy;
1.1453 + return Z_OK;
1.1454 +}
1.1455 +
1.1456 +int ZEXPORT inflateUndermine(strm, subvert)
1.1457 +z_streamp strm;
1.1458 +int subvert;
1.1459 +{
1.1460 + struct inflate_state FAR *state;
1.1461 +
1.1462 + if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
1.1463 + state = (struct inflate_state FAR *)strm->state;
1.1464 + state->sane = !subvert;
1.1465 +#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
1.1466 + return Z_OK;
1.1467 +#else
1.1468 + state->sane = 1;
1.1469 + return Z_DATA_ERROR;
1.1470 +#endif
1.1471 +}
1.1472 +
1.1473 +long ZEXPORT inflateMark(strm)
1.1474 +z_streamp strm;
1.1475 +{
1.1476 + struct inflate_state FAR *state;
1.1477 +
1.1478 + if (strm == Z_NULL || strm->state == Z_NULL) return -1L << 16;
1.1479 + state = (struct inflate_state FAR *)strm->state;
1.1480 + return ((long)(state->back) << 16) +
1.1481 + (state->mode == COPY ? state->length :
1.1482 + (state->mode == MATCH ? state->was - state->length : 0));
1.1483 +}
