1 |
/* inflate.c -- zlib decompression |
2 |
* Copyright (C) 1995-2012 Mark Adler |
3 |
* For conditions of distribution and use, see copyright notice in zlib.h |
4 |
*/ |
5 |
|
6 |
/* |
7 |
* Change history: |
8 |
* |
9 |
* 1.2.beta0 24 Nov 2002 |
10 |
* - First version -- complete rewrite of inflate to simplify code, avoid |
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* creation of window when not needed, minimize use of window when it is |
12 |
* needed, make inffast.c even faster, implement gzip decoding, and to |
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* improve code readability and style over the previous zlib inflate code |
14 |
* |
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* 1.2.beta1 25 Nov 2002 |
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* - Use pointers for available input and output checking in inffast.c |
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* - Remove input and output counters in inffast.c |
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* - Change inffast.c entry and loop from avail_in >= 7 to >= 6 |
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* - Remove unnecessary second byte pull from length extra in inffast.c |
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* - Unroll direct copy to three copies per loop in inffast.c |
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* |
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* 1.2.beta2 4 Dec 2002 |
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* - Change external routine names to reduce potential conflicts |
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* - Correct filename to inffixed.h for fixed tables in inflate.c |
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* - Make hbuf[] unsigned char to match parameter type in inflate.c |
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* - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset) |
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* to avoid negation problem on Alphas (64 bit) in inflate.c |
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* |
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* 1.2.beta3 22 Dec 2002 |
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* - Add comments on state->bits assertion in inffast.c |
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* - Add comments on op field in inftrees.h |
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* - Fix bug in reuse of allocated window after inflateReset() |
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* - Remove bit fields--back to byte structure for speed |
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* - Remove distance extra == 0 check in inflate_fast()--only helps for lengths |
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* - Change post-increments to pre-increments in inflate_fast(), PPC biased? |
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* - Add compile time option, POSTINC, to use post-increments instead (Intel?) |
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* - Make MATCH copy in inflate() much faster for when inflate_fast() not used |
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* - Use local copies of stream next and avail values, as well as local bit |
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* buffer and bit count in inflate()--for speed when inflate_fast() not used |
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* |
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* 1.2.beta4 1 Jan 2003 |
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* - Split ptr - 257 statements in inflate_table() to avoid compiler warnings |
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* - Move a comment on output buffer sizes from inffast.c to inflate.c |
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* - Add comments in inffast.c to introduce the inflate_fast() routine |
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* - Rearrange window copies in inflate_fast() for speed and simplification |
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* - Unroll last copy for window match in inflate_fast() |
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* - Use local copies of window variables in inflate_fast() for speed |
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* - Pull out common wnext == 0 case for speed in inflate_fast() |
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* - Make op and len in inflate_fast() unsigned for consistency |
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* - Add FAR to lcode and dcode declarations in inflate_fast() |
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* - Simplified bad distance check in inflate_fast() |
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* - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new |
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* source file infback.c to provide a call-back interface to inflate for |
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* programs like gzip and unzip -- uses window as output buffer to avoid |
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* window copying |
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* |
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* 1.2.beta5 1 Jan 2003 |
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* - Improved inflateBack() interface to allow the caller to provide initial |
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* input in strm. |
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* - Fixed stored blocks bug in inflateBack() |
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* |
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* 1.2.beta6 4 Jan 2003 |
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* - Added comments in inffast.c on effectiveness of POSTINC |
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* - Typecasting all around to reduce compiler warnings |
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* - Changed loops from while (1) or do {} while (1) to for (;;), again to |
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* make compilers happy |
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* - Changed type of window in inflateBackInit() to unsigned char * |
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* |
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* 1.2.beta7 27 Jan 2003 |
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* - Changed many types to unsigned or unsigned short to avoid warnings |
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* - Added inflateCopy() function |
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* |
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* 1.2.0 9 Mar 2003 |
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* - Changed inflateBack() interface to provide separate opaque descriptors |
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* for the in() and out() functions |
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* - Changed inflateBack() argument and in_func typedef to swap the length |
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* and buffer address return values for the input function |
78 |
* - Check next_in and next_out for Z_NULL on entry to inflate() |
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* |
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* The history for versions after 1.2.0 are in ChangeLog in zlib distribution. |
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*/ |
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|
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#include "zutil.h" |
84 |
#include "inftrees.h" |
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#include "inflate.h" |
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#include "inffast.h" |
87 |
|
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#ifdef MAKEFIXED |
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# ifndef BUILDFIXED |
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# define BUILDFIXED |
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# endif |
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#endif |
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|
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/* function prototypes */ |
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local void fixedtables OF((struct inflate_state FAR *state)); |
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local int updatewindow OF((z_streamp strm, const unsigned char FAR *end, |
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unsigned copy)); |
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#ifdef BUILDFIXED |
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void makefixed OF((void)); |
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#endif |
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local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf, |
102 |
unsigned len)); |
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|
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int ZEXPORT inflateResetKeep(strm) |
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z_streamp strm; |
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{ |
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struct inflate_state FAR *state; |
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|
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if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
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state = (struct inflate_state FAR *)strm->state; |
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strm->total_in = strm->total_out = state->total = 0; |
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strm->msg = Z_NULL; |
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if (state->wrap) /* to support ill-conceived Java test suite */ |
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strm->adler = state->wrap & 1; |
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state->mode = HEAD; |
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state->last = 0; |
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state->havedict = 0; |
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state->dmax = 32768U; |
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state->head = Z_NULL; |
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state->hold = 0; |
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state->bits = 0; |
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state->lencode = state->distcode = state->next = state->codes; |
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state->sane = 1; |
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state->back = -1; |
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Tracev((stderr, "inflate: reset\n")); |
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return Z_OK; |
127 |
} |
128 |
|
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int ZEXPORT inflateReset(strm) |
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z_streamp strm; |
131 |
{ |
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struct inflate_state FAR *state; |
133 |
|
134 |
if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
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state = (struct inflate_state FAR *)strm->state; |
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state->wsize = 0; |
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state->whave = 0; |
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state->wnext = 0; |
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return inflateResetKeep(strm); |
140 |
} |
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|
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int ZEXPORT inflateReset2(strm, windowBits) |
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z_streamp strm; |
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int windowBits; |
145 |
{ |
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int wrap; |
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struct inflate_state FAR *state; |
148 |
|
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/* get the state */ |
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if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
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state = (struct inflate_state FAR *)strm->state; |
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|
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/* extract wrap request from windowBits parameter */ |
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if (windowBits < 0) { |
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wrap = 0; |
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windowBits = -windowBits; |
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} |
158 |
else { |
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wrap = (windowBits >> 4) + 1; |
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#ifdef GUNZIP |
161 |
if (windowBits < 48) |
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windowBits &= 15; |
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#endif |
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} |
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|
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/* set number of window bits, free window if different */ |
167 |
if (windowBits && (windowBits < 8 || windowBits > 15)) |
168 |
return Z_STREAM_ERROR; |
169 |
if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) { |
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ZFREE(strm, state->window); |
171 |
state->window = Z_NULL; |
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} |
173 |
|
174 |
/* update state and reset the rest of it */ |
175 |
state->wrap = wrap; |
176 |
state->wbits = (unsigned)windowBits; |
177 |
return inflateReset(strm); |
178 |
} |
179 |
|
180 |
int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size) |
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z_streamp strm; |
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int windowBits; |
183 |
const char *version; |
184 |
int stream_size; |
185 |
{ |
186 |
int ret; |
187 |
struct inflate_state FAR *state; |
188 |
|
189 |
if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || |
190 |
stream_size != (int)(sizeof(z_stream))) |
191 |
return Z_VERSION_ERROR; |
192 |
if (strm == Z_NULL) return Z_STREAM_ERROR; |
193 |
strm->msg = Z_NULL; /* in case we return an error */ |
194 |
if (strm->zalloc == (alloc_func)0) { |
195 |
#ifdef Z_SOLO |
196 |
return Z_STREAM_ERROR; |
197 |
#else |
198 |
strm->zalloc = zcalloc; |
199 |
strm->opaque = (voidpf)0; |
200 |
#endif |
201 |
} |
202 |
if (strm->zfree == (free_func)0) |
203 |
#ifdef Z_SOLO |
204 |
return Z_STREAM_ERROR; |
205 |
#else |
206 |
strm->zfree = zcfree; |
207 |
#endif |
208 |
state = (struct inflate_state FAR *) |
209 |
ZALLOC(strm, 1, sizeof(struct inflate_state)); |
210 |
if (state == Z_NULL) return Z_MEM_ERROR; |
211 |
Tracev((stderr, "inflate: allocated\n")); |
212 |
strm->state = (struct internal_state FAR *)state; |
213 |
state->window = Z_NULL; |
214 |
ret = inflateReset2(strm, windowBits); |
215 |
if (ret != Z_OK) { |
216 |
ZFREE(strm, state); |
217 |
strm->state = Z_NULL; |
218 |
} |
219 |
return ret; |
220 |
} |
221 |
|
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int ZEXPORT inflateInit_(strm, version, stream_size) |
223 |
z_streamp strm; |
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const char *version; |
225 |
int stream_size; |
226 |
{ |
227 |
return inflateInit2_(strm, DEF_WBITS, version, stream_size); |
228 |
} |
229 |
|
230 |
int ZEXPORT inflatePrime(strm, bits, value) |
231 |
z_streamp strm; |
232 |
int bits; |
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int value; |
234 |
{ |
235 |
struct inflate_state FAR *state; |
236 |
|
237 |
if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
238 |
state = (struct inflate_state FAR *)strm->state; |
239 |
if (bits < 0) { |
240 |
state->hold = 0; |
241 |
state->bits = 0; |
242 |
return Z_OK; |
243 |
} |
244 |
if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR; |
245 |
value &= (1L << bits) - 1; |
246 |
state->hold += value << state->bits; |
247 |
state->bits += bits; |
248 |
return Z_OK; |
249 |
} |
250 |
|
251 |
/* |
252 |
Return state with length and distance decoding tables and index sizes set to |
253 |
fixed code decoding. Normally this returns fixed tables from inffixed.h. |
254 |
If BUILDFIXED is defined, then instead this routine builds the tables the |
255 |
first time it's called, and returns those tables the first time and |
256 |
thereafter. This reduces the size of the code by about 2K bytes, in |
257 |
exchange for a little execution time. However, BUILDFIXED should not be |
258 |
used for threaded applications, since the rewriting of the tables and virgin |
259 |
may not be thread-safe. |
260 |
*/ |
261 |
local void fixedtables(state) |
262 |
struct inflate_state FAR *state; |
263 |
{ |
264 |
#ifdef BUILDFIXED |
265 |
static int virgin = 1; |
266 |
static code *lenfix, *distfix; |
267 |
static code fixed[544]; |
268 |
|
269 |
/* build fixed huffman tables if first call (may not be thread safe) */ |
270 |
if (virgin) { |
271 |
unsigned sym, bits; |
272 |
static code *next; |
273 |
|
274 |
/* literal/length table */ |
275 |
sym = 0; |
276 |
while (sym < 144) state->lens[sym++] = 8; |
277 |
while (sym < 256) state->lens[sym++] = 9; |
278 |
while (sym < 280) state->lens[sym++] = 7; |
279 |
while (sym < 288) state->lens[sym++] = 8; |
280 |
next = fixed; |
281 |
lenfix = next; |
282 |
bits = 9; |
283 |
inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work); |
284 |
|
285 |
/* distance table */ |
286 |
sym = 0; |
287 |
while (sym < 32) state->lens[sym++] = 5; |
288 |
distfix = next; |
289 |
bits = 5; |
290 |
inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work); |
291 |
|
292 |
/* do this just once */ |
293 |
virgin = 0; |
294 |
} |
295 |
#else /* !BUILDFIXED */ |
296 |
# include "inffixed.h" |
297 |
#endif /* BUILDFIXED */ |
298 |
state->lencode = lenfix; |
299 |
state->lenbits = 9; |
300 |
state->distcode = distfix; |
301 |
state->distbits = 5; |
302 |
} |
303 |
|
304 |
#ifdef MAKEFIXED |
305 |
#include <stdio.h> |
306 |
|
307 |
/* |
308 |
Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also |
309 |
defines BUILDFIXED, so the tables are built on the fly. makefixed() writes |
310 |
those tables to stdout, which would be piped to inffixed.h. A small program |
311 |
can simply call makefixed to do this: |
312 |
|
313 |
void makefixed(void); |
314 |
|
315 |
int main(void) |
316 |
{ |
317 |
makefixed(); |
318 |
return 0; |
319 |
} |
320 |
|
321 |
Then that can be linked with zlib built with MAKEFIXED defined and run: |
322 |
|
323 |
a.out > inffixed.h |
324 |
*/ |
325 |
void makefixed() |
326 |
{ |
327 |
unsigned low, size; |
328 |
struct inflate_state state; |
329 |
|
330 |
fixedtables(&state); |
331 |
puts(" /* inffixed.h -- table for decoding fixed codes"); |
332 |
puts(" * Generated automatically by makefixed()."); |
333 |
puts(" */"); |
334 |
puts(""); |
335 |
puts(" /* WARNING: this file should *not* be used by applications."); |
336 |
puts(" It is part of the implementation of this library and is"); |
337 |
puts(" subject to change. Applications should only use zlib.h."); |
338 |
puts(" */"); |
339 |
puts(""); |
340 |
size = 1U << 9; |
341 |
printf(" static const code lenfix[%u] = {", size); |
342 |
low = 0; |
343 |
for (;;) { |
344 |
if ((low % 7) == 0) printf("\n "); |
345 |
printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op, |
346 |
state.lencode[low].bits, state.lencode[low].val); |
347 |
if (++low == size) break; |
348 |
putchar(','); |
349 |
} |
350 |
puts("\n };"); |
351 |
size = 1U << 5; |
352 |
printf("\n static const code distfix[%u] = {", size); |
353 |
low = 0; |
354 |
for (;;) { |
355 |
if ((low % 6) == 0) printf("\n "); |
356 |
printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits, |
357 |
state.distcode[low].val); |
358 |
if (++low == size) break; |
359 |
putchar(','); |
360 |
} |
361 |
puts("\n };"); |
362 |
} |
363 |
#endif /* MAKEFIXED */ |
364 |
|
365 |
/* |
366 |
Update the window with the last wsize (normally 32K) bytes written before |
367 |
returning. If window does not exist yet, create it. This is only called |
368 |
when a window is already in use, or when output has been written during this |
369 |
inflate call, but the end of the deflate stream has not been reached yet. |
370 |
It is also called to create a window for dictionary data when a dictionary |
371 |
is loaded. |
372 |
|
373 |
Providing output buffers larger than 32K to inflate() should provide a speed |
374 |
advantage, since only the last 32K of output is copied to the sliding window |
375 |
upon return from inflate(), and since all distances after the first 32K of |
376 |
output will fall in the output data, making match copies simpler and faster. |
377 |
The advantage may be dependent on the size of the processor's data caches. |
378 |
*/ |
379 |
local int updatewindow(strm, end, copy) |
380 |
z_streamp strm; |
381 |
const Bytef *end; |
382 |
unsigned copy; |
383 |
{ |
384 |
struct inflate_state FAR *state; |
385 |
unsigned dist; |
386 |
|
387 |
state = (struct inflate_state FAR *)strm->state; |
388 |
|
389 |
/* if it hasn't been done already, allocate space for the window */ |
390 |
if (state->window == Z_NULL) { |
391 |
state->window = (unsigned char FAR *) |
392 |
ZALLOC(strm, 1U << state->wbits, |
393 |
sizeof(unsigned char)); |
394 |
if (state->window == Z_NULL) return 1; |
395 |
} |
396 |
|
397 |
/* if window not in use yet, initialize */ |
398 |
if (state->wsize == 0) { |
399 |
state->wsize = 1U << state->wbits; |
400 |
state->wnext = 0; |
401 |
state->whave = 0; |
402 |
} |
403 |
|
404 |
/* copy state->wsize or less output bytes into the circular window */ |
405 |
if (copy >= state->wsize) { |
406 |
zmemcpy(state->window, end - state->wsize, state->wsize); |
407 |
state->wnext = 0; |
408 |
state->whave = state->wsize; |
409 |
} |
410 |
else { |
411 |
dist = state->wsize - state->wnext; |
412 |
if (dist > copy) dist = copy; |
413 |
zmemcpy(state->window + state->wnext, end - copy, dist); |
414 |
copy -= dist; |
415 |
if (copy) { |
416 |
zmemcpy(state->window, end - copy, copy); |
417 |
state->wnext = copy; |
418 |
state->whave = state->wsize; |
419 |
} |
420 |
else { |
421 |
state->wnext += dist; |
422 |
if (state->wnext == state->wsize) state->wnext = 0; |
423 |
if (state->whave < state->wsize) state->whave += dist; |
424 |
} |
425 |
} |
426 |
return 0; |
427 |
} |
428 |
|
429 |
/* Macros for inflate(): */ |
430 |
|
431 |
/* check function to use adler32() for zlib or crc32() for gzip */ |
432 |
#ifdef GUNZIP |
433 |
# define UPDATE(check, buf, len) \ |
434 |
(state->flags ? crc32(check, buf, len) : adler32(check, buf, len)) |
435 |
#else |
436 |
# define UPDATE(check, buf, len) adler32(check, buf, len) |
437 |
#endif |
438 |
|
439 |
/* check macros for header crc */ |
440 |
#ifdef GUNZIP |
441 |
# define CRC2(check, word) \ |
442 |
do { \ |
443 |
hbuf[0] = (unsigned char)(word); \ |
444 |
hbuf[1] = (unsigned char)((word) >> 8); \ |
445 |
check = crc32(check, hbuf, 2); \ |
446 |
} while (0) |
447 |
|
448 |
# define CRC4(check, word) \ |
449 |
do { \ |
450 |
hbuf[0] = (unsigned char)(word); \ |
451 |
hbuf[1] = (unsigned char)((word) >> 8); \ |
452 |
hbuf[2] = (unsigned char)((word) >> 16); \ |
453 |
hbuf[3] = (unsigned char)((word) >> 24); \ |
454 |
check = crc32(check, hbuf, 4); \ |
455 |
} while (0) |
456 |
#endif |
457 |
|
458 |
/* Load registers with state in inflate() for speed */ |
459 |
#define LOAD() \ |
460 |
do { \ |
461 |
put = strm->next_out; \ |
462 |
left = strm->avail_out; \ |
463 |
next = strm->next_in; \ |
464 |
have = strm->avail_in; \ |
465 |
hold = state->hold; \ |
466 |
bits = state->bits; \ |
467 |
} while (0) |
468 |
|
469 |
/* Restore state from registers in inflate() */ |
470 |
#define RESTORE() \ |
471 |
do { \ |
472 |
strm->next_out = put; \ |
473 |
strm->avail_out = left; \ |
474 |
strm->next_in = next; \ |
475 |
strm->avail_in = have; \ |
476 |
state->hold = hold; \ |
477 |
state->bits = bits; \ |
478 |
} while (0) |
479 |
|
480 |
/* Clear the input bit accumulator */ |
481 |
#define INITBITS() \ |
482 |
do { \ |
483 |
hold = 0; \ |
484 |
bits = 0; \ |
485 |
} while (0) |
486 |
|
487 |
/* Get a byte of input into the bit accumulator, or return from inflate() |
488 |
if there is no input available. */ |
489 |
#define PULLBYTE() \ |
490 |
do { \ |
491 |
if (have == 0) goto inf_leave; \ |
492 |
have--; \ |
493 |
hold += (unsigned long)(*next++) << bits; \ |
494 |
bits += 8; \ |
495 |
} while (0) |
496 |
|
497 |
/* Assure that there are at least n bits in the bit accumulator. If there is |
498 |
not enough available input to do that, then return from inflate(). */ |
499 |
#define NEEDBITS(n) \ |
500 |
do { \ |
501 |
while (bits < (unsigned)(n)) \ |
502 |
PULLBYTE(); \ |
503 |
} while (0) |
504 |
|
505 |
/* Return the low n bits of the bit accumulator (n < 16) */ |
506 |
#define BITS(n) \ |
507 |
((unsigned)hold & ((1U << (n)) - 1)) |
508 |
|
509 |
/* Remove n bits from the bit accumulator */ |
510 |
#define DROPBITS(n) \ |
511 |
do { \ |
512 |
hold >>= (n); \ |
513 |
bits -= (unsigned)(n); \ |
514 |
} while (0) |
515 |
|
516 |
/* Remove zero to seven bits as needed to go to a byte boundary */ |
517 |
#define BYTEBITS() \ |
518 |
do { \ |
519 |
hold >>= bits & 7; \ |
520 |
bits -= bits & 7; \ |
521 |
} while (0) |
522 |
|
523 |
/* |
524 |
inflate() uses a state machine to process as much input data and generate as |
525 |
much output data as possible before returning. The state machine is |
526 |
structured roughly as follows: |
527 |
|
528 |
for (;;) switch (state) { |
529 |
... |
530 |
case STATEn: |
531 |
if (not enough input data or output space to make progress) |
532 |
return; |
533 |
... make progress ... |
534 |
state = STATEm; |
535 |
break; |
536 |
... |
537 |
} |
538 |
|
539 |
so when inflate() is called again, the same case is attempted again, and |
540 |
if the appropriate resources are provided, the machine proceeds to the |
541 |
next state. The NEEDBITS() macro is usually the way the state evaluates |
542 |
whether it can proceed or should return. NEEDBITS() does the return if |
543 |
the requested bits are not available. The typical use of the BITS macros |
544 |
is: |
545 |
|
546 |
NEEDBITS(n); |
547 |
... do something with BITS(n) ... |
548 |
DROPBITS(n); |
549 |
|
550 |
where NEEDBITS(n) either returns from inflate() if there isn't enough |
551 |
input left to load n bits into the accumulator, or it continues. BITS(n) |
552 |
gives the low n bits in the accumulator. When done, DROPBITS(n) drops |
553 |
the low n bits off the accumulator. INITBITS() clears the accumulator |
554 |
and sets the number of available bits to zero. BYTEBITS() discards just |
555 |
enough bits to put the accumulator on a byte boundary. After BYTEBITS() |
556 |
and a NEEDBITS(8), then BITS(8) would return the next byte in the stream. |
557 |
|
558 |
NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return |
559 |
if there is no input available. The decoding of variable length codes uses |
560 |
PULLBYTE() directly in order to pull just enough bytes to decode the next |
561 |
code, and no more. |
562 |
|
563 |
Some states loop until they get enough input, making sure that enough |
564 |
state information is maintained to continue the loop where it left off |
565 |
if NEEDBITS() returns in the loop. For example, want, need, and keep |
566 |
would all have to actually be part of the saved state in case NEEDBITS() |
567 |
returns: |
568 |
|
569 |
case STATEw: |
570 |
while (want < need) { |
571 |
NEEDBITS(n); |
572 |
keep[want++] = BITS(n); |
573 |
DROPBITS(n); |
574 |
} |
575 |
state = STATEx; |
576 |
case STATEx: |
577 |
|
578 |
As shown above, if the next state is also the next case, then the break |
579 |
is omitted. |
580 |
|
581 |
A state may also return if there is not enough output space available to |
582 |
complete that state. Those states are copying stored data, writing a |
583 |
literal byte, and copying a matching string. |
584 |
|
585 |
When returning, a "goto inf_leave" is used to update the total counters, |
586 |
update the check value, and determine whether any progress has been made |
587 |
during that inflate() call in order to return the proper return code. |
588 |
Progress is defined as a change in either strm->avail_in or strm->avail_out. |
589 |
When there is a window, goto inf_leave will update the window with the last |
590 |
output written. If a goto inf_leave occurs in the middle of decompression |
591 |
and there is no window currently, goto inf_leave will create one and copy |
592 |
output to the window for the next call of inflate(). |
593 |
|
594 |
In this implementation, the flush parameter of inflate() only affects the |
595 |
return code (per zlib.h). inflate() always writes as much as possible to |
596 |
strm->next_out, given the space available and the provided input--the effect |
597 |
documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers |
598 |
the allocation of and copying into a sliding window until necessary, which |
599 |
provides the effect documented in zlib.h for Z_FINISH when the entire input |
600 |
stream available. So the only thing the flush parameter actually does is: |
601 |
when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it |
602 |
will return Z_BUF_ERROR if it has not reached the end of the stream. |
603 |
*/ |
604 |
|
605 |
int ZEXPORT inflate(strm, flush) |
606 |
z_streamp strm; |
607 |
int flush; |
608 |
{ |
609 |
struct inflate_state FAR *state; |
610 |
z_const unsigned char FAR *next; /* next input */ |
611 |
unsigned char FAR *put; /* next output */ |
612 |
unsigned have, left; /* available input and output */ |
613 |
unsigned long hold; /* bit buffer */ |
614 |
unsigned bits; /* bits in bit buffer */ |
615 |
unsigned in, out; /* save starting available input and output */ |
616 |
unsigned copy; /* number of stored or match bytes to copy */ |
617 |
unsigned char FAR *from; /* where to copy match bytes from */ |
618 |
code here; /* current decoding table entry */ |
619 |
code last; /* parent table entry */ |
620 |
unsigned len; /* length to copy for repeats, bits to drop */ |
621 |
int ret; /* return code */ |
622 |
#ifdef GUNZIP |
623 |
unsigned char hbuf[4]; /* buffer for gzip header crc calculation */ |
624 |
#endif |
625 |
static const unsigned short order[19] = /* permutation of code lengths */ |
626 |
{16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; |
627 |
|
628 |
if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL || |
629 |
(strm->next_in == Z_NULL && strm->avail_in != 0)) |
630 |
return Z_STREAM_ERROR; |
631 |
|
632 |
state = (struct inflate_state FAR *)strm->state; |
633 |
if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */ |
634 |
LOAD(); |
635 |
in = have; |
636 |
out = left; |
637 |
ret = Z_OK; |
638 |
for (;;) |
639 |
switch (state->mode) { |
640 |
case HEAD: |
641 |
if (state->wrap == 0) { |
642 |
state->mode = TYPEDO; |
643 |
break; |
644 |
} |
645 |
NEEDBITS(16); |
646 |
#ifdef GUNZIP |
647 |
if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */ |
648 |
state->check = crc32(0L, Z_NULL, 0); |
649 |
CRC2(state->check, hold); |
650 |
INITBITS(); |
651 |
state->mode = FLAGS; |
652 |
break; |
653 |
} |
654 |
state->flags = 0; /* expect zlib header */ |
655 |
if (state->head != Z_NULL) |
656 |
state->head->done = -1; |
657 |
if (!(state->wrap & 1) || /* check if zlib header allowed */ |
658 |
#else |
659 |
if ( |
660 |
#endif |
661 |
((BITS(8) << 8) + (hold >> 8)) % 31) { |
662 |
strm->msg = (char *)"incorrect header check"; |
663 |
state->mode = BAD; |
664 |
break; |
665 |
} |
666 |
if (BITS(4) != Z_DEFLATED) { |
667 |
strm->msg = (char *)"unknown compression method"; |
668 |
state->mode = BAD; |
669 |
break; |
670 |
} |
671 |
DROPBITS(4); |
672 |
len = BITS(4) + 8; |
673 |
if (state->wbits == 0) |
674 |
state->wbits = len; |
675 |
else if (len > state->wbits) { |
676 |
strm->msg = (char *)"invalid window size"; |
677 |
state->mode = BAD; |
678 |
break; |
679 |
} |
680 |
state->dmax = 1U << len; |
681 |
Tracev((stderr, "inflate: zlib header ok\n")); |
682 |
strm->adler = state->check = adler32(0L, Z_NULL, 0); |
683 |
state->mode = hold & 0x200 ? DICTID : TYPE; |
684 |
INITBITS(); |
685 |
break; |
686 |
#ifdef GUNZIP |
687 |
case FLAGS: |
688 |
NEEDBITS(16); |
689 |
state->flags = (int)(hold); |
690 |
if ((state->flags & 0xff) != Z_DEFLATED) { |
691 |
strm->msg = (char *)"unknown compression method"; |
692 |
state->mode = BAD; |
693 |
break; |
694 |
} |
695 |
if (state->flags & 0xe000) { |
696 |
strm->msg = (char *)"unknown header flags set"; |
697 |
state->mode = BAD; |
698 |
break; |
699 |
} |
700 |
if (state->head != Z_NULL) |
701 |
state->head->text = (int)((hold >> 8) & 1); |
702 |
if (state->flags & 0x0200) CRC2(state->check, hold); |
703 |
INITBITS(); |
704 |
state->mode = TIME; |
705 |
case TIME: |
706 |
NEEDBITS(32); |
707 |
if (state->head != Z_NULL) |
708 |
state->head->time = hold; |
709 |
if (state->flags & 0x0200) CRC4(state->check, hold); |
710 |
INITBITS(); |
711 |
state->mode = OS; |
712 |
case OS: |
713 |
NEEDBITS(16); |
714 |
if (state->head != Z_NULL) { |
715 |
state->head->xflags = (int)(hold & 0xff); |
716 |
state->head->os = (int)(hold >> 8); |
717 |
} |
718 |
if (state->flags & 0x0200) CRC2(state->check, hold); |
719 |
INITBITS(); |
720 |
state->mode = EXLEN; |
721 |
case EXLEN: |
722 |
if (state->flags & 0x0400) { |
723 |
NEEDBITS(16); |
724 |
state->length = (unsigned)(hold); |
725 |
if (state->head != Z_NULL) |
726 |
state->head->extra_len = (unsigned)hold; |
727 |
if (state->flags & 0x0200) CRC2(state->check, hold); |
728 |
INITBITS(); |
729 |
} |
730 |
else if (state->head != Z_NULL) |
731 |
state->head->extra = Z_NULL; |
732 |
state->mode = EXTRA; |
733 |
case EXTRA: |
734 |
if (state->flags & 0x0400) { |
735 |
copy = state->length; |
736 |
if (copy > have) copy = have; |
737 |
if (copy) { |
738 |
if (state->head != Z_NULL && |
739 |
state->head->extra != Z_NULL) { |
740 |
len = state->head->extra_len - state->length; |
741 |
zmemcpy(state->head->extra + len, next, |
742 |
len + copy > state->head->extra_max ? |
743 |
state->head->extra_max - len : copy); |
744 |
} |
745 |
if (state->flags & 0x0200) |
746 |
state->check = crc32(state->check, next, copy); |
747 |
have -= copy; |
748 |
next += copy; |
749 |
state->length -= copy; |
750 |
} |
751 |
if (state->length) goto inf_leave; |
752 |
} |
753 |
state->length = 0; |
754 |
state->mode = NAME; |
755 |
case NAME: |
756 |
if (state->flags & 0x0800) { |
757 |
if (have == 0) goto inf_leave; |
758 |
copy = 0; |
759 |
do { |
760 |
len = (unsigned)(next[copy++]); |
761 |
if (state->head != Z_NULL && |
762 |
state->head->name != Z_NULL && |
763 |
state->length < state->head->name_max) |
764 |
state->head->name[state->length++] = len; |
765 |
} while (len && copy < have); |
766 |
if (state->flags & 0x0200) |
767 |
state->check = crc32(state->check, next, copy); |
768 |
have -= copy; |
769 |
next += copy; |
770 |
if (len) goto inf_leave; |
771 |
} |
772 |
else if (state->head != Z_NULL) |
773 |
state->head->name = Z_NULL; |
774 |
state->length = 0; |
775 |
state->mode = COMMENT; |
776 |
case COMMENT: |
777 |
if (state->flags & 0x1000) { |
778 |
if (have == 0) goto inf_leave; |
779 |
copy = 0; |
780 |
do { |
781 |
len = (unsigned)(next[copy++]); |
782 |
if (state->head != Z_NULL && |
783 |
state->head->comment != Z_NULL && |
784 |
state->length < state->head->comm_max) |
785 |
state->head->comment[state->length++] = len; |
786 |
} while (len && copy < have); |
787 |
if (state->flags & 0x0200) |
788 |
state->check = crc32(state->check, next, copy); |
789 |
have -= copy; |
790 |
next += copy; |
791 |
if (len) goto inf_leave; |
792 |
} |
793 |
else if (state->head != Z_NULL) |
794 |
state->head->comment = Z_NULL; |
795 |
state->mode = HCRC; |
796 |
case HCRC: |
797 |
if (state->flags & 0x0200) { |
798 |
NEEDBITS(16); |
799 |
if (hold != (state->check & 0xffff)) { |
800 |
strm->msg = (char *)"header crc mismatch"; |
801 |
state->mode = BAD; |
802 |
break; |
803 |
} |
804 |
INITBITS(); |
805 |
} |
806 |
if (state->head != Z_NULL) { |
807 |
state->head->hcrc = (int)((state->flags >> 9) & 1); |
808 |
state->head->done = 1; |
809 |
} |
810 |
strm->adler = state->check = crc32(0L, Z_NULL, 0); |
811 |
state->mode = TYPE; |
812 |
break; |
813 |
#endif |
814 |
case DICTID: |
815 |
NEEDBITS(32); |
816 |
strm->adler = state->check = ZSWAP32(hold); |
817 |
INITBITS(); |
818 |
state->mode = DICT; |
819 |
case DICT: |
820 |
if (state->havedict == 0) { |
821 |
RESTORE(); |
822 |
return Z_NEED_DICT; |
823 |
} |
824 |
strm->adler = state->check = adler32(0L, Z_NULL, 0); |
825 |
state->mode = TYPE; |
826 |
case TYPE: |
827 |
if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave; |
828 |
case TYPEDO: |
829 |
if (state->last) { |
830 |
BYTEBITS(); |
831 |
state->mode = CHECK; |
832 |
break; |
833 |
} |
834 |
NEEDBITS(3); |
835 |
state->last = BITS(1); |
836 |
DROPBITS(1); |
837 |
switch (BITS(2)) { |
838 |
case 0: /* stored block */ |
839 |
Tracev((stderr, "inflate: stored block%s\n", |
840 |
state->last ? " (last)" : "")); |
841 |
state->mode = STORED; |
842 |
break; |
843 |
case 1: /* fixed block */ |
844 |
fixedtables(state); |
845 |
Tracev((stderr, "inflate: fixed codes block%s\n", |
846 |
state->last ? " (last)" : "")); |
847 |
state->mode = LEN_; /* decode codes */ |
848 |
if (flush == Z_TREES) { |
849 |
DROPBITS(2); |
850 |
goto inf_leave; |
851 |
} |
852 |
break; |
853 |
case 2: /* dynamic block */ |
854 |
Tracev((stderr, "inflate: dynamic codes block%s\n", |
855 |
state->last ? " (last)" : "")); |
856 |
state->mode = TABLE; |
857 |
break; |
858 |
case 3: |
859 |
strm->msg = (char *)"invalid block type"; |
860 |
state->mode = BAD; |
861 |
} |
862 |
DROPBITS(2); |
863 |
break; |
864 |
case STORED: |
865 |
BYTEBITS(); /* go to byte boundary */ |
866 |
NEEDBITS(32); |
867 |
if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { |
868 |
strm->msg = (char *)"invalid stored block lengths"; |
869 |
state->mode = BAD; |
870 |
break; |
871 |
} |
872 |
state->length = (unsigned)hold & 0xffff; |
873 |
Tracev((stderr, "inflate: stored length %u\n", |
874 |
state->length)); |
875 |
INITBITS(); |
876 |
state->mode = COPY_; |
877 |
if (flush == Z_TREES) goto inf_leave; |
878 |
case COPY_: |
879 |
state->mode = COPY; |
880 |
case COPY: |
881 |
copy = state->length; |
882 |
if (copy) { |
883 |
if (copy > have) copy = have; |
884 |
if (copy > left) copy = left; |
885 |
if (copy == 0) goto inf_leave; |
886 |
zmemcpy(put, next, copy); |
887 |
have -= copy; |
888 |
next += copy; |
889 |
left -= copy; |
890 |
put += copy; |
891 |
state->length -= copy; |
892 |
break; |
893 |
} |
894 |
Tracev((stderr, "inflate: stored end\n")); |
895 |
state->mode = TYPE; |
896 |
break; |
897 |
case TABLE: |
898 |
NEEDBITS(14); |
899 |
state->nlen = BITS(5) + 257; |
900 |
DROPBITS(5); |
901 |
state->ndist = BITS(5) + 1; |
902 |
DROPBITS(5); |
903 |
state->ncode = BITS(4) + 4; |
904 |
DROPBITS(4); |
905 |
#ifndef PKZIP_BUG_WORKAROUND |
906 |
if (state->nlen > 286 || state->ndist > 30) { |
907 |
strm->msg = (char *)"too many length or distance symbols"; |
908 |
state->mode = BAD; |
909 |
break; |
910 |
} |
911 |
#endif |
912 |
Tracev((stderr, "inflate: table sizes ok\n")); |
913 |
state->have = 0; |
914 |
state->mode = LENLENS; |
915 |
case LENLENS: |
916 |
while (state->have < state->ncode) { |
917 |
NEEDBITS(3); |
918 |
state->lens[order[state->have++]] = (unsigned short)BITS(3); |
919 |
DROPBITS(3); |
920 |
} |
921 |
while (state->have < 19) |
922 |
state->lens[order[state->have++]] = 0; |
923 |
state->next = state->codes; |
924 |
state->lencode = (const code FAR *)(state->next); |
925 |
state->lenbits = 7; |
926 |
ret = inflate_table(CODES, state->lens, 19, &(state->next), |
927 |
&(state->lenbits), state->work); |
928 |
if (ret) { |
929 |
strm->msg = (char *)"invalid code lengths set"; |
930 |
state->mode = BAD; |
931 |
break; |
932 |
} |
933 |
Tracev((stderr, "inflate: code lengths ok\n")); |
934 |
state->have = 0; |
935 |
state->mode = CODELENS; |
936 |
case CODELENS: |
937 |
while (state->have < state->nlen + state->ndist) { |
938 |
for (;;) { |
939 |
here = state->lencode[BITS(state->lenbits)]; |
940 |
if ((unsigned)(here.bits) <= bits) break; |
941 |
PULLBYTE(); |
942 |
} |
943 |
if (here.val < 16) { |
944 |
DROPBITS(here.bits); |
945 |
state->lens[state->have++] = here.val; |
946 |
} |
947 |
else { |
948 |
if (here.val == 16) { |
949 |
NEEDBITS(here.bits + 2); |
950 |
DROPBITS(here.bits); |
951 |
if (state->have == 0) { |
952 |
strm->msg = (char *)"invalid bit length repeat"; |
953 |
state->mode = BAD; |
954 |
break; |
955 |
} |
956 |
len = state->lens[state->have - 1]; |
957 |
copy = 3 + BITS(2); |
958 |
DROPBITS(2); |
959 |
} |
960 |
else if (here.val == 17) { |
961 |
NEEDBITS(here.bits + 3); |
962 |
DROPBITS(here.bits); |
963 |
len = 0; |
964 |
copy = 3 + BITS(3); |
965 |
DROPBITS(3); |
966 |
} |
967 |
else { |
968 |
NEEDBITS(here.bits + 7); |
969 |
DROPBITS(here.bits); |
970 |
len = 0; |
971 |
copy = 11 + BITS(7); |
972 |
DROPBITS(7); |
973 |
} |
974 |
if (state->have + copy > state->nlen + state->ndist) { |
975 |
strm->msg = (char *)"invalid bit length repeat"; |
976 |
state->mode = BAD; |
977 |
break; |
978 |
} |
979 |
while (copy--) |
980 |
state->lens[state->have++] = (unsigned short)len; |
981 |
} |
982 |
} |
983 |
|
984 |
/* handle error breaks in while */ |
985 |
if (state->mode == BAD) break; |
986 |
|
987 |
/* check for end-of-block code (better have one) */ |
988 |
if (state->lens[256] == 0) { |
989 |
strm->msg = (char *)"invalid code -- missing end-of-block"; |
990 |
state->mode = BAD; |
991 |
break; |
992 |
} |
993 |
|
994 |
/* build code tables -- note: do not change the lenbits or distbits |
995 |
values here (9 and 6) without reading the comments in inftrees.h |
996 |
concerning the ENOUGH constants, which depend on those values */ |
997 |
state->next = state->codes; |
998 |
state->lencode = (const code FAR *)(state->next); |
999 |
state->lenbits = 9; |
1000 |
ret = inflate_table(LENS, state->lens, state->nlen, &(state->next), |
1001 |
&(state->lenbits), state->work); |
1002 |
if (ret) { |
1003 |
strm->msg = (char *)"invalid literal/lengths set"; |
1004 |
state->mode = BAD; |
1005 |
break; |
1006 |
} |
1007 |
state->distcode = (const code FAR *)(state->next); |
1008 |
state->distbits = 6; |
1009 |
ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist, |
1010 |
&(state->next), &(state->distbits), state->work); |
1011 |
if (ret) { |
1012 |
strm->msg = (char *)"invalid distances set"; |
1013 |
state->mode = BAD; |
1014 |
break; |
1015 |
} |
1016 |
Tracev((stderr, "inflate: codes ok\n")); |
1017 |
state->mode = LEN_; |
1018 |
if (flush == Z_TREES) goto inf_leave; |
1019 |
case LEN_: |
1020 |
state->mode = LEN; |
1021 |
case LEN: |
1022 |
if (have >= 6 && left >= 258) { |
1023 |
RESTORE(); |
1024 |
inflate_fast(strm, out); |
1025 |
LOAD(); |
1026 |
if (state->mode == TYPE) |
1027 |
state->back = -1; |
1028 |
break; |
1029 |
} |
1030 |
state->back = 0; |
1031 |
for (;;) { |
1032 |
here = state->lencode[BITS(state->lenbits)]; |
1033 |
if ((unsigned)(here.bits) <= bits) break; |
1034 |
PULLBYTE(); |
1035 |
} |
1036 |
if (here.op && (here.op & 0xf0) == 0) { |
1037 |
last = here; |
1038 |
for (;;) { |
1039 |
here = state->lencode[last.val + |
1040 |
(BITS(last.bits + last.op) >> last.bits)]; |
1041 |
if ((unsigned)(last.bits + here.bits) <= bits) break; |
1042 |
PULLBYTE(); |
1043 |
} |
1044 |
DROPBITS(last.bits); |
1045 |
state->back += last.bits; |
1046 |
} |
1047 |
DROPBITS(here.bits); |
1048 |
state->back += here.bits; |
1049 |
state->length = (unsigned)here.val; |
1050 |
if ((int)(here.op) == 0) { |
1051 |
Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ? |
1052 |
"inflate: literal '%c'\n" : |
1053 |
"inflate: literal 0x%02x\n", here.val)); |
1054 |
state->mode = LIT; |
1055 |
break; |
1056 |
} |
1057 |
if (here.op & 32) { |
1058 |
Tracevv((stderr, "inflate: end of block\n")); |
1059 |
state->back = -1; |
1060 |
state->mode = TYPE; |
1061 |
break; |
1062 |
} |
1063 |
if (here.op & 64) { |
1064 |
strm->msg = (char *)"invalid literal/length code"; |
1065 |
state->mode = BAD; |
1066 |
break; |
1067 |
} |
1068 |
state->extra = (unsigned)(here.op) & 15; |
1069 |
state->mode = LENEXT; |
1070 |
case LENEXT: |
1071 |
if (state->extra) { |
1072 |
NEEDBITS(state->extra); |
1073 |
state->length += BITS(state->extra); |
1074 |
DROPBITS(state->extra); |
1075 |
state->back += state->extra; |
1076 |
} |
1077 |
Tracevv((stderr, "inflate: length %u\n", state->length)); |
1078 |
state->was = state->length; |
1079 |
state->mode = DIST; |
1080 |
case DIST: |
1081 |
for (;;) { |
1082 |
here = state->distcode[BITS(state->distbits)]; |
1083 |
if ((unsigned)(here.bits) <= bits) break; |
1084 |
PULLBYTE(); |
1085 |
} |
1086 |
if ((here.op & 0xf0) == 0) { |
1087 |
last = here; |
1088 |
for (;;) { |
1089 |
here = state->distcode[last.val + |
1090 |
(BITS(last.bits + last.op) >> last.bits)]; |
1091 |
if ((unsigned)(last.bits + here.bits) <= bits) break; |
1092 |
PULLBYTE(); |
1093 |
} |
1094 |
DROPBITS(last.bits); |
1095 |
state->back += last.bits; |
1096 |
} |
1097 |
DROPBITS(here.bits); |
1098 |
state->back += here.bits; |
1099 |
if (here.op & 64) { |
1100 |
strm->msg = (char *)"invalid distance code"; |
1101 |
state->mode = BAD; |
1102 |
break; |
1103 |
} |
1104 |
state->offset = (unsigned)here.val; |
1105 |
state->extra = (unsigned)(here.op) & 15; |
1106 |
state->mode = DISTEXT; |
1107 |
case DISTEXT: |
1108 |
if (state->extra) { |
1109 |
NEEDBITS(state->extra); |
1110 |
state->offset += BITS(state->extra); |
1111 |
DROPBITS(state->extra); |
1112 |
state->back += state->extra; |
1113 |
} |
1114 |
#ifdef INFLATE_STRICT |
1115 |
if (state->offset > state->dmax) { |
1116 |
strm->msg = (char *)"invalid distance too far back"; |
1117 |
state->mode = BAD; |
1118 |
break; |
1119 |
} |
1120 |
#endif |
1121 |
Tracevv((stderr, "inflate: distance %u\n", state->offset)); |
1122 |
state->mode = MATCH; |
1123 |
case MATCH: |
1124 |
if (left == 0) goto inf_leave; |
1125 |
copy = out - left; |
1126 |
if (state->offset > copy) { /* copy from window */ |
1127 |
copy = state->offset - copy; |
1128 |
if (copy > state->whave) { |
1129 |
if (state->sane) { |
1130 |
strm->msg = (char *)"invalid distance too far back"; |
1131 |
state->mode = BAD; |
1132 |
break; |
1133 |
} |
1134 |
#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR |
1135 |
Trace((stderr, "inflate.c too far\n")); |
1136 |
copy -= state->whave; |
1137 |
if (copy > state->length) copy = state->length; |
1138 |
if (copy > left) copy = left; |
1139 |
left -= copy; |
1140 |
state->length -= copy; |
1141 |
do { |
1142 |
*put++ = 0; |
1143 |
} while (--copy); |
1144 |
if (state->length == 0) state->mode = LEN; |
1145 |
break; |
1146 |
#endif |
1147 |
} |
1148 |
if (copy > state->wnext) { |
1149 |
copy -= state->wnext; |
1150 |
from = state->window + (state->wsize - copy); |
1151 |
} |
1152 |
else |
1153 |
from = state->window + (state->wnext - copy); |
1154 |
if (copy > state->length) copy = state->length; |
1155 |
} |
1156 |
else { /* copy from output */ |
1157 |
from = put - state->offset; |
1158 |
copy = state->length; |
1159 |
} |
1160 |
if (copy > left) copy = left; |
1161 |
left -= copy; |
1162 |
state->length -= copy; |
1163 |
do { |
1164 |
*put++ = *from++; |
1165 |
} while (--copy); |
1166 |
if (state->length == 0) state->mode = LEN; |
1167 |
break; |
1168 |
case LIT: |
1169 |
if (left == 0) goto inf_leave; |
1170 |
*put++ = (unsigned char)(state->length); |
1171 |
left--; |
1172 |
state->mode = LEN; |
1173 |
break; |
1174 |
case CHECK: |
1175 |
if (state->wrap) { |
1176 |
NEEDBITS(32); |
1177 |
out -= left; |
1178 |
strm->total_out += out; |
1179 |
state->total += out; |
1180 |
if (out) |
1181 |
strm->adler = state->check = |
1182 |
UPDATE(state->check, put - out, out); |
1183 |
out = left; |
1184 |
if (( |
1185 |
#ifdef GUNZIP |
1186 |
state->flags ? hold : |
1187 |
#endif |
1188 |
ZSWAP32(hold)) != state->check) { |
1189 |
strm->msg = (char *)"incorrect data check"; |
1190 |
state->mode = BAD; |
1191 |
break; |
1192 |
} |
1193 |
INITBITS(); |
1194 |
Tracev((stderr, "inflate: check matches trailer\n")); |
1195 |
} |
1196 |
#ifdef GUNZIP |
1197 |
state->mode = LENGTH; |
1198 |
case LENGTH: |
1199 |
if (state->wrap && state->flags) { |
1200 |
NEEDBITS(32); |
1201 |
if (hold != (state->total & 0xffffffffUL)) { |
1202 |
strm->msg = (char *)"incorrect length check"; |
1203 |
state->mode = BAD; |
1204 |
break; |
1205 |
} |
1206 |
INITBITS(); |
1207 |
Tracev((stderr, "inflate: length matches trailer\n")); |
1208 |
} |
1209 |
#endif |
1210 |
state->mode = DONE; |
1211 |
case DONE: |
1212 |
ret = Z_STREAM_END; |
1213 |
goto inf_leave; |
1214 |
case BAD: |
1215 |
ret = Z_DATA_ERROR; |
1216 |
goto inf_leave; |
1217 |
case MEM: |
1218 |
return Z_MEM_ERROR; |
1219 |
case SYNC: |
1220 |
default: |
1221 |
return Z_STREAM_ERROR; |
1222 |
} |
1223 |
|
1224 |
/* |
1225 |
Return from inflate(), updating the total counts and the check value. |
1226 |
If there was no progress during the inflate() call, return a buffer |
1227 |
error. Call updatewindow() to create and/or update the window state. |
1228 |
Note: a memory error from inflate() is non-recoverable. |
1229 |
*/ |
1230 |
inf_leave: |
1231 |
RESTORE(); |
1232 |
if (state->wsize || (out != strm->avail_out && state->mode < BAD && |
1233 |
(state->mode < CHECK || flush != Z_FINISH))) |
1234 |
if (updatewindow(strm, strm->next_out, out - strm->avail_out)) { |
1235 |
state->mode = MEM; |
1236 |
return Z_MEM_ERROR; |
1237 |
} |
1238 |
in -= strm->avail_in; |
1239 |
out -= strm->avail_out; |
1240 |
strm->total_in += in; |
1241 |
strm->total_out += out; |
1242 |
state->total += out; |
1243 |
if (state->wrap && out) |
1244 |
strm->adler = state->check = |
1245 |
UPDATE(state->check, strm->next_out - out, out); |
1246 |
strm->data_type = state->bits + (state->last ? 64 : 0) + |
1247 |
(state->mode == TYPE ? 128 : 0) + |
1248 |
(state->mode == LEN_ || state->mode == COPY_ ? 256 : 0); |
1249 |
if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK) |
1250 |
ret = Z_BUF_ERROR; |
1251 |
return ret; |
1252 |
} |
1253 |
|
1254 |
int ZEXPORT inflateEnd(strm) |
1255 |
z_streamp strm; |
1256 |
{ |
1257 |
struct inflate_state FAR *state; |
1258 |
if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0) |
1259 |
return Z_STREAM_ERROR; |
1260 |
state = (struct inflate_state FAR *)strm->state; |
1261 |
if (state->window != Z_NULL) ZFREE(strm, state->window); |
1262 |
ZFREE(strm, strm->state); |
1263 |
strm->state = Z_NULL; |
1264 |
Tracev((stderr, "inflate: end\n")); |
1265 |
return Z_OK; |
1266 |
} |
1267 |
|
1268 |
int ZEXPORT inflateGetDictionary(strm, dictionary, dictLength) |
1269 |
z_streamp strm; |
1270 |
Bytef *dictionary; |
1271 |
uInt *dictLength; |
1272 |
{ |
1273 |
struct inflate_state FAR *state; |
1274 |
|
1275 |
/* check state */ |
1276 |
if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
1277 |
state = (struct inflate_state FAR *)strm->state; |
1278 |
|
1279 |
/* copy dictionary */ |
1280 |
if (state->whave && dictionary != Z_NULL) { |
1281 |
zmemcpy(dictionary, state->window + state->wnext, |
1282 |
state->whave - state->wnext); |
1283 |
zmemcpy(dictionary + state->whave - state->wnext, |
1284 |
state->window, state->wnext); |
1285 |
} |
1286 |
if (dictLength != Z_NULL) |
1287 |
*dictLength = state->whave; |
1288 |
return Z_OK; |
1289 |
} |
1290 |
|
1291 |
int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength) |
1292 |
z_streamp strm; |
1293 |
const Bytef *dictionary; |
1294 |
uInt dictLength; |
1295 |
{ |
1296 |
struct inflate_state FAR *state; |
1297 |
unsigned long dictid; |
1298 |
int ret; |
1299 |
|
1300 |
/* check state */ |
1301 |
if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
1302 |
state = (struct inflate_state FAR *)strm->state; |
1303 |
if (state->wrap != 0 && state->mode != DICT) |
1304 |
return Z_STREAM_ERROR; |
1305 |
|
1306 |
/* check for correct dictionary identifier */ |
1307 |
if (state->mode == DICT) { |
1308 |
dictid = adler32(0L, Z_NULL, 0); |
1309 |
dictid = adler32(dictid, dictionary, dictLength); |
1310 |
if (dictid != state->check) |
1311 |
return Z_DATA_ERROR; |
1312 |
} |
1313 |
|
1314 |
/* copy dictionary to window using updatewindow(), which will amend the |
1315 |
existing dictionary if appropriate */ |
1316 |
ret = updatewindow(strm, dictionary + dictLength, dictLength); |
1317 |
if (ret) { |
1318 |
state->mode = MEM; |
1319 |
return Z_MEM_ERROR; |
1320 |
} |
1321 |
state->havedict = 1; |
1322 |
Tracev((stderr, "inflate: dictionary set\n")); |
1323 |
return Z_OK; |
1324 |
} |
1325 |
|
1326 |
int ZEXPORT inflateGetHeader(strm, head) |
1327 |
z_streamp strm; |
1328 |
gz_headerp head; |
1329 |
{ |
1330 |
struct inflate_state FAR *state; |
1331 |
|
1332 |
/* check state */ |
1333 |
if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
1334 |
state = (struct inflate_state FAR *)strm->state; |
1335 |
if ((state->wrap & 2) == 0) return Z_STREAM_ERROR; |
1336 |
|
1337 |
/* save header structure */ |
1338 |
state->head = head; |
1339 |
head->done = 0; |
1340 |
return Z_OK; |
1341 |
} |
1342 |
|
1343 |
/* |
1344 |
Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found |
1345 |
or when out of input. When called, *have is the number of pattern bytes |
1346 |
found in order so far, in 0..3. On return *have is updated to the new |
1347 |
state. If on return *have equals four, then the pattern was found and the |
1348 |
return value is how many bytes were read including the last byte of the |
1349 |
pattern. If *have is less than four, then the pattern has not been found |
1350 |
yet and the return value is len. In the latter case, syncsearch() can be |
1351 |
called again with more data and the *have state. *have is initialized to |
1352 |
zero for the first call. |
1353 |
*/ |
1354 |
local unsigned syncsearch(have, buf, len) |
1355 |
unsigned FAR *have; |
1356 |
const unsigned char FAR *buf; |
1357 |
unsigned len; |
1358 |
{ |
1359 |
unsigned got; |
1360 |
unsigned next; |
1361 |
|
1362 |
got = *have; |
1363 |
next = 0; |
1364 |
while (next < len && got < 4) { |
1365 |
if ((int)(buf[next]) == (got < 2 ? 0 : 0xff)) |
1366 |
got++; |
1367 |
else if (buf[next]) |
1368 |
got = 0; |
1369 |
else |
1370 |
got = 4 - got; |
1371 |
next++; |
1372 |
} |
1373 |
*have = got; |
1374 |
return next; |
1375 |
} |
1376 |
|
1377 |
int ZEXPORT inflateSync(strm) |
1378 |
z_streamp strm; |
1379 |
{ |
1380 |
unsigned len; /* number of bytes to look at or looked at */ |
1381 |
unsigned long in, out; /* temporary to save total_in and total_out */ |
1382 |
unsigned char buf[4]; /* to restore bit buffer to byte string */ |
1383 |
struct inflate_state FAR *state; |
1384 |
|
1385 |
/* check parameters */ |
1386 |
if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
1387 |
state = (struct inflate_state FAR *)strm->state; |
1388 |
if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR; |
1389 |
|
1390 |
/* if first time, start search in bit buffer */ |
1391 |
if (state->mode != SYNC) { |
1392 |
state->mode = SYNC; |
1393 |
state->hold <<= state->bits & 7; |
1394 |
state->bits -= state->bits & 7; |
1395 |
len = 0; |
1396 |
while (state->bits >= 8) { |
1397 |
buf[len++] = (unsigned char)(state->hold); |
1398 |
state->hold >>= 8; |
1399 |
state->bits -= 8; |
1400 |
} |
1401 |
state->have = 0; |
1402 |
syncsearch(&(state->have), buf, len); |
1403 |
} |
1404 |
|
1405 |
/* search available input */ |
1406 |
len = syncsearch(&(state->have), strm->next_in, strm->avail_in); |
1407 |
strm->avail_in -= len; |
1408 |
strm->next_in += len; |
1409 |
strm->total_in += len; |
1410 |
|
1411 |
/* return no joy or set up to restart inflate() on a new block */ |
1412 |
if (state->have != 4) return Z_DATA_ERROR; |
1413 |
in = strm->total_in; out = strm->total_out; |
1414 |
inflateReset(strm); |
1415 |
strm->total_in = in; strm->total_out = out; |
1416 |
state->mode = TYPE; |
1417 |
return Z_OK; |
1418 |
} |
1419 |
|
1420 |
/* |
1421 |
Returns true if inflate is currently at the end of a block generated by |
1422 |
Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP |
1423 |
implementation to provide an additional safety check. PPP uses |
1424 |
Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored |
1425 |
block. When decompressing, PPP checks that at the end of input packet, |
1426 |
inflate is waiting for these length bytes. |
1427 |
*/ |
1428 |
int ZEXPORT inflateSyncPoint(strm) |
1429 |
z_streamp strm; |
1430 |
{ |
1431 |
struct inflate_state FAR *state; |
1432 |
|
1433 |
if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
1434 |
state = (struct inflate_state FAR *)strm->state; |
1435 |
return state->mode == STORED && state->bits == 0; |
1436 |
} |
1437 |
|
1438 |
int ZEXPORT inflateCopy(dest, source) |
1439 |
z_streamp dest; |
1440 |
z_streamp source; |
1441 |
{ |
1442 |
struct inflate_state FAR *state; |
1443 |
struct inflate_state FAR *copy; |
1444 |
unsigned char FAR *window; |
1445 |
unsigned wsize; |
1446 |
|
1447 |
/* check input */ |
1448 |
if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL || |
1449 |
source->zalloc == (alloc_func)0 || source->zfree == (free_func)0) |
1450 |
return Z_STREAM_ERROR; |
1451 |
state = (struct inflate_state FAR *)source->state; |
1452 |
|
1453 |
/* allocate space */ |
1454 |
copy = (struct inflate_state FAR *) |
1455 |
ZALLOC(source, 1, sizeof(struct inflate_state)); |
1456 |
if (copy == Z_NULL) return Z_MEM_ERROR; |
1457 |
window = Z_NULL; |
1458 |
if (state->window != Z_NULL) { |
1459 |
window = (unsigned char FAR *) |
1460 |
ZALLOC(source, 1U << state->wbits, sizeof(unsigned char)); |
1461 |
if (window == Z_NULL) { |
1462 |
ZFREE(source, copy); |
1463 |
return Z_MEM_ERROR; |
1464 |
} |
1465 |
} |
1466 |
|
1467 |
/* copy state */ |
1468 |
zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream)); |
1469 |
zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state)); |
1470 |
if (state->lencode >= state->codes && |
1471 |
state->lencode <= state->codes + ENOUGH - 1) { |
1472 |
copy->lencode = copy->codes + (state->lencode - state->codes); |
1473 |
copy->distcode = copy->codes + (state->distcode - state->codes); |
1474 |
} |
1475 |
copy->next = copy->codes + (state->next - state->codes); |
1476 |
if (window != Z_NULL) { |
1477 |
wsize = 1U << state->wbits; |
1478 |
zmemcpy(window, state->window, wsize); |
1479 |
} |
1480 |
copy->window = window; |
1481 |
dest->state = (struct internal_state FAR *)copy; |
1482 |
return Z_OK; |
1483 |
} |
1484 |
|
1485 |
int ZEXPORT inflateUndermine(strm, subvert) |
1486 |
z_streamp strm; |
1487 |
int subvert; |
1488 |
{ |
1489 |
struct inflate_state FAR *state; |
1490 |
|
1491 |
if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
1492 |
state = (struct inflate_state FAR *)strm->state; |
1493 |
state->sane = !subvert; |
1494 |
#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR |
1495 |
return Z_OK; |
1496 |
#else |
1497 |
state->sane = 1; |
1498 |
return Z_DATA_ERROR; |
1499 |
#endif |
1500 |
} |
1501 |
|
1502 |
long ZEXPORT inflateMark(strm) |
1503 |
z_streamp strm; |
1504 |
{ |
1505 |
struct inflate_state FAR *state; |
1506 |
|
1507 |
if (strm == Z_NULL || strm->state == Z_NULL) return -1L << 16; |
1508 |
state = (struct inflate_state FAR *)strm->state; |
1509 |
return ((long)(state->back) << 16) + |
1510 |
(state->mode == COPY ? state->length : |
1511 |
(state->mode == MATCH ? state->was - state->length : 0)); |
1512 |
} |