Annotation of sys/lib/libz/inflate.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: inflate.c,v 1.13 2005/07/20 15:56:46 millert Exp $ */
! 2: /* inflate.c -- zlib decompression
! 3: * Copyright (C) 1995-2005 Mark Adler
! 4: * For conditions of distribution and use, see copyright notice in zlib.h
! 5: */
! 6:
! 7: /*
! 8: * Change history:
! 9: *
! 10: * 1.2.beta0 24 Nov 2002
! 11: * - First version -- complete rewrite of inflate to simplify code, avoid
! 12: * creation of window when not needed, minimize use of window when it is
! 13: * needed, make inffast.c even faster, implement gzip decoding, and to
! 14: * improve code readability and style over the previous zlib inflate code
! 15: *
! 16: * 1.2.beta1 25 Nov 2002
! 17: * - Use pointers for available input and output checking in inffast.c
! 18: * - Remove input and output counters in inffast.c
! 19: * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
! 20: * - Remove unnecessary second byte pull from length extra in inffast.c
! 21: * - Unroll direct copy to three copies per loop in inffast.c
! 22: *
! 23: * 1.2.beta2 4 Dec 2002
! 24: * - Change external routine names to reduce potential conflicts
! 25: * - Correct filename to inffixed.h for fixed tables in inflate.c
! 26: * - Make hbuf[] unsigned char to match parameter type in inflate.c
! 27: * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
! 28: * to avoid negation problem on Alphas (64 bit) in inflate.c
! 29: *
! 30: * 1.2.beta3 22 Dec 2002
! 31: * - Add comments on state->bits assertion in inffast.c
! 32: * - Add comments on op field in inftrees.h
! 33: * - Fix bug in reuse of allocated window after inflateReset()
! 34: * - Remove bit fields--back to byte structure for speed
! 35: * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
! 36: * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
! 37: * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
! 38: * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
! 39: * - Use local copies of stream next and avail values, as well as local bit
! 40: * buffer and bit count in inflate()--for speed when inflate_fast() not used
! 41: *
! 42: * 1.2.beta4 1 Jan 2003
! 43: * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
! 44: * - Move a comment on output buffer sizes from inffast.c to inflate.c
! 45: * - Add comments in inffast.c to introduce the inflate_fast() routine
! 46: * - Rearrange window copies in inflate_fast() for speed and simplification
! 47: * - Unroll last copy for window match in inflate_fast()
! 48: * - Use local copies of window variables in inflate_fast() for speed
! 49: * - Pull out common write == 0 case for speed in inflate_fast()
! 50: * - Make op and len in inflate_fast() unsigned for consistency
! 51: * - Add FAR to lcode and dcode declarations in inflate_fast()
! 52: * - Simplified bad distance check in inflate_fast()
! 53: * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
! 54: * source file infback.c to provide a call-back interface to inflate for
! 55: * programs like gzip and unzip -- uses window as output buffer to avoid
! 56: * window copying
! 57: *
! 58: * 1.2.beta5 1 Jan 2003
! 59: * - Improved inflateBack() interface to allow the caller to provide initial
! 60: * input in strm.
! 61: * - Fixed stored blocks bug in inflateBack()
! 62: *
! 63: * 1.2.beta6 4 Jan 2003
! 64: * - Added comments in inffast.c on effectiveness of POSTINC
! 65: * - Typecasting all around to reduce compiler warnings
! 66: * - Changed loops from while (1) or do {} while (1) to for (;;), again to
! 67: * make compilers happy
! 68: * - Changed type of window in inflateBackInit() to unsigned char *
! 69: *
! 70: * 1.2.beta7 27 Jan 2003
! 71: * - Changed many types to unsigned or unsigned short to avoid warnings
! 72: * - Added inflateCopy() function
! 73: *
! 74: * 1.2.0 9 Mar 2003
! 75: * - Changed inflateBack() interface to provide separate opaque descriptors
! 76: * for the in() and out() functions
! 77: * - Changed inflateBack() argument and in_func typedef to swap the length
! 78: * and buffer address return values for the input function
! 79: * - Check next_in and next_out for Z_NULL on entry to inflate()
! 80: *
! 81: * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
! 82: */
! 83:
! 84: #include "zutil.h"
! 85: #include "inftrees.h"
! 86: #include "inflate.h"
! 87: #include "inffast.h"
! 88:
! 89: #ifdef MAKEFIXED
! 90: # ifndef BUILDFIXED
! 91: # define BUILDFIXED
! 92: # endif
! 93: #endif
! 94:
! 95: /* function prototypes */
! 96: local void fixedtables OF((struct inflate_state FAR *state));
! 97: local int updatewindow OF((z_streamp strm, unsigned out));
! 98: #ifdef BUILDFIXED
! 99: void makefixed OF((void));
! 100: #endif
! 101: local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf,
! 102: unsigned len));
! 103:
! 104: int ZEXPORT inflateReset(strm)
! 105: z_streamp strm;
! 106: {
! 107: struct inflate_state FAR *state;
! 108:
! 109: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
! 110: state = (struct inflate_state FAR *)strm->state;
! 111: strm->total_in = strm->total_out = state->total = 0;
! 112: strm->msg = Z_NULL;
! 113: strm->adler = 1; /* to support ill-conceived Java test suite */
! 114: state->mode = HEAD;
! 115: state->last = 0;
! 116: state->havedict = 0;
! 117: state->dmax = 32768U;
! 118: state->head = Z_NULL;
! 119: state->wsize = 0;
! 120: state->whave = 0;
! 121: state->write = 0;
! 122: state->hold = 0;
! 123: state->bits = 0;
! 124: state->lencode = state->distcode = state->next = state->codes;
! 125: Tracev((stderr, "inflate: reset\n"));
! 126: return Z_OK;
! 127: }
! 128:
! 129: int ZEXPORT inflatePrime(strm, bits, value)
! 130: z_streamp strm;
! 131: int bits;
! 132: int value;
! 133: {
! 134: struct inflate_state FAR *state;
! 135:
! 136: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
! 137: state = (struct inflate_state FAR *)strm->state;
! 138: if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR;
! 139: value &= (1L << bits) - 1;
! 140: state->hold += value << state->bits;
! 141: state->bits += bits;
! 142: return Z_OK;
! 143: }
! 144:
! 145: int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
! 146: z_streamp strm;
! 147: int windowBits;
! 148: const char *version;
! 149: int stream_size;
! 150: {
! 151: struct inflate_state FAR *state;
! 152:
! 153: if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
! 154: stream_size != (int)(sizeof(z_stream)))
! 155: return Z_VERSION_ERROR;
! 156: if (strm == Z_NULL) return Z_STREAM_ERROR;
! 157: strm->msg = Z_NULL; /* in case we return an error */
! 158: if (strm->zalloc == (alloc_func)0) {
! 159: strm->zalloc = zcalloc;
! 160: strm->opaque = (voidpf)0;
! 161: }
! 162: if (strm->zfree == (free_func)0) strm->zfree = zcfree;
! 163: state = (struct inflate_state FAR *)
! 164: ZALLOC(strm, 1, sizeof(struct inflate_state));
! 165: if (state == Z_NULL) return Z_MEM_ERROR;
! 166: Tracev((stderr, "inflate: allocated\n"));
! 167: strm->state = (struct internal_state FAR *)state;
! 168: if (windowBits < 0) {
! 169: state->wrap = 0;
! 170: windowBits = -windowBits;
! 171: }
! 172: else {
! 173: state->wrap = (windowBits >> 4) + 1;
! 174: #ifdef GUNZIP
! 175: if (windowBits < 48) windowBits &= 15;
! 176: #endif
! 177: }
! 178: if (windowBits < 8 || windowBits > 15) {
! 179: ZFREE(strm, state);
! 180: strm->state = Z_NULL;
! 181: return Z_STREAM_ERROR;
! 182: }
! 183: state->wbits = (unsigned)windowBits;
! 184: state->window = Z_NULL;
! 185: return inflateReset(strm);
! 186: }
! 187:
! 188: int ZEXPORT inflateInit_(strm, version, stream_size)
! 189: z_streamp strm;
! 190: const char *version;
! 191: int stream_size;
! 192: {
! 193: return inflateInit2_(strm, DEF_WBITS, version, stream_size);
! 194: }
! 195:
! 196: /*
! 197: Return state with length and distance decoding tables and index sizes set to
! 198: fixed code decoding. Normally this returns fixed tables from inffixed.h.
! 199: If BUILDFIXED is defined, then instead this routine builds the tables the
! 200: first time it's called, and returns those tables the first time and
! 201: thereafter. This reduces the size of the code by about 2K bytes, in
! 202: exchange for a little execution time. However, BUILDFIXED should not be
! 203: used for threaded applications, since the rewriting of the tables and virgin
! 204: may not be thread-safe.
! 205: */
! 206: local void fixedtables(state)
! 207: struct inflate_state FAR *state;
! 208: {
! 209: #ifdef BUILDFIXED
! 210: static int virgin = 1;
! 211: static code *lenfix, *distfix;
! 212: static code fixed[544];
! 213:
! 214: /* build fixed huffman tables if first call (may not be thread safe) */
! 215: if (virgin) {
! 216: unsigned sym, bits;
! 217: static code *next;
! 218:
! 219: /* literal/length table */
! 220: sym = 0;
! 221: while (sym < 144) state->lens[sym++] = 8;
! 222: while (sym < 256) state->lens[sym++] = 9;
! 223: while (sym < 280) state->lens[sym++] = 7;
! 224: while (sym < 288) state->lens[sym++] = 8;
! 225: next = fixed;
! 226: lenfix = next;
! 227: bits = 9;
! 228: inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
! 229:
! 230: /* distance table */
! 231: sym = 0;
! 232: while (sym < 32) state->lens[sym++] = 5;
! 233: distfix = next;
! 234: bits = 5;
! 235: inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
! 236:
! 237: /* do this just once */
! 238: virgin = 0;
! 239: }
! 240: #else /* !BUILDFIXED */
! 241: # include "inffixed.h"
! 242: #endif /* BUILDFIXED */
! 243: state->lencode = lenfix;
! 244: state->lenbits = 9;
! 245: state->distcode = distfix;
! 246: state->distbits = 5;
! 247: }
! 248:
! 249: #ifdef MAKEFIXED
! 250: #include <stdio.h>
! 251:
! 252: /*
! 253: Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also
! 254: defines BUILDFIXED, so the tables are built on the fly. makefixed() writes
! 255: those tables to stdout, which would be piped to inffixed.h. A small program
! 256: can simply call makefixed to do this:
! 257:
! 258: void makefixed(void);
! 259:
! 260: int main(void)
! 261: {
! 262: makefixed();
! 263: return 0;
! 264: }
! 265:
! 266: Then that can be linked with zlib built with MAKEFIXED defined and run:
! 267:
! 268: a.out > inffixed.h
! 269: */
! 270: void makefixed()
! 271: {
! 272: unsigned low, size;
! 273: struct inflate_state state;
! 274:
! 275: fixedtables(&state);
! 276: puts(" /* inffixed.h -- table for decoding fixed codes");
! 277: puts(" * Generated automatically by makefixed().");
! 278: puts(" */");
! 279: puts("");
! 280: puts(" /* WARNING: this file should *not* be used by applications.");
! 281: puts(" It is part of the implementation of this library and is");
! 282: puts(" subject to change. Applications should only use zlib.h.");
! 283: puts(" */");
! 284: puts("");
! 285: size = 1U << 9;
! 286: printf(" static const code lenfix[%u] = {", size);
! 287: low = 0;
! 288: for (;;) {
! 289: if ((low % 7) == 0) printf("\n ");
! 290: printf("{%u,%u,%d}", state.lencode[low].op, state.lencode[low].bits,
! 291: state.lencode[low].val);
! 292: if (++low == size) break;
! 293: putchar(',');
! 294: }
! 295: puts("\n };");
! 296: size = 1U << 5;
! 297: printf("\n static const code distfix[%u] = {", size);
! 298: low = 0;
! 299: for (;;) {
! 300: if ((low % 6) == 0) printf("\n ");
! 301: printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
! 302: state.distcode[low].val);
! 303: if (++low == size) break;
! 304: putchar(',');
! 305: }
! 306: puts("\n };");
! 307: }
! 308: #endif /* MAKEFIXED */
! 309:
! 310: /*
! 311: Update the window with the last wsize (normally 32K) bytes written before
! 312: returning. If window does not exist yet, create it. This is only called
! 313: when a window is already in use, or when output has been written during this
! 314: inflate call, but the end of the deflate stream has not been reached yet.
! 315: It is also called to create a window for dictionary data when a dictionary
! 316: is loaded.
! 317:
! 318: Providing output buffers larger than 32K to inflate() should provide a speed
! 319: advantage, since only the last 32K of output is copied to the sliding window
! 320: upon return from inflate(), and since all distances after the first 32K of
! 321: output will fall in the output data, making match copies simpler and faster.
! 322: The advantage may be dependent on the size of the processor's data caches.
! 323: */
! 324: local int updatewindow(strm, out)
! 325: z_streamp strm;
! 326: unsigned out;
! 327: {
! 328: struct inflate_state FAR *state;
! 329: unsigned copy, dist;
! 330:
! 331: state = (struct inflate_state FAR *)strm->state;
! 332:
! 333: /* if it hasn't been done already, allocate space for the window */
! 334: if (state->window == Z_NULL) {
! 335: state->window = (unsigned char FAR *)
! 336: ZALLOC(strm, 1U << state->wbits,
! 337: sizeof(unsigned char));
! 338: if (state->window == Z_NULL) return 1;
! 339: }
! 340:
! 341: /* if window not in use yet, initialize */
! 342: if (state->wsize == 0) {
! 343: state->wsize = 1U << state->wbits;
! 344: state->write = 0;
! 345: state->whave = 0;
! 346: }
! 347:
! 348: /* copy state->wsize or less output bytes into the circular window */
! 349: copy = out - strm->avail_out;
! 350: if (copy >= state->wsize) {
! 351: zmemcpy(state->window, strm->next_out - state->wsize, state->wsize);
! 352: state->write = 0;
! 353: state->whave = state->wsize;
! 354: }
! 355: else {
! 356: dist = state->wsize - state->write;
! 357: if (dist > copy) dist = copy;
! 358: zmemcpy(state->window + state->write, strm->next_out - copy, dist);
! 359: copy -= dist;
! 360: if (copy) {
! 361: zmemcpy(state->window, strm->next_out - copy, copy);
! 362: state->write = copy;
! 363: state->whave = state->wsize;
! 364: }
! 365: else {
! 366: state->write += dist;
! 367: if (state->write == state->wsize) state->write = 0;
! 368: if (state->whave < state->wsize) state->whave += dist;
! 369: }
! 370: }
! 371: return 0;
! 372: }
! 373:
! 374: /* Macros for inflate(): */
! 375:
! 376: /* check function to use adler32() for zlib or crc32() for gzip */
! 377: #ifdef GUNZIP
! 378: # define UPDATE(check, buf, len) \
! 379: (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
! 380: #else
! 381: # define UPDATE(check, buf, len) adler32(check, buf, len)
! 382: #endif
! 383:
! 384: /* check macros for header crc */
! 385: #ifdef GUNZIP
! 386: # define CRC2(check, word) \
! 387: do { \
! 388: hbuf[0] = (unsigned char)(word); \
! 389: hbuf[1] = (unsigned char)((word) >> 8); \
! 390: check = crc32(check, hbuf, 2); \
! 391: } while (0)
! 392:
! 393: # define CRC4(check, word) \
! 394: do { \
! 395: hbuf[0] = (unsigned char)(word); \
! 396: hbuf[1] = (unsigned char)((word) >> 8); \
! 397: hbuf[2] = (unsigned char)((word) >> 16); \
! 398: hbuf[3] = (unsigned char)((word) >> 24); \
! 399: check = crc32(check, hbuf, 4); \
! 400: } while (0)
! 401: #endif
! 402:
! 403: /* Load registers with state in inflate() for speed */
! 404: #define LOAD() \
! 405: do { \
! 406: put = strm->next_out; \
! 407: left = strm->avail_out; \
! 408: next = strm->next_in; \
! 409: have = strm->avail_in; \
! 410: hold = state->hold; \
! 411: bits = state->bits; \
! 412: } while (0)
! 413:
! 414: /* Restore state from registers in inflate() */
! 415: #define RESTORE() \
! 416: do { \
! 417: strm->next_out = put; \
! 418: strm->avail_out = left; \
! 419: strm->next_in = next; \
! 420: strm->avail_in = have; \
! 421: state->hold = hold; \
! 422: state->bits = bits; \
! 423: } while (0)
! 424:
! 425: /* Clear the input bit accumulator */
! 426: #define INITBITS() \
! 427: do { \
! 428: hold = 0; \
! 429: bits = 0; \
! 430: } while (0)
! 431:
! 432: /* Get a byte of input into the bit accumulator, or return from inflate()
! 433: if there is no input available. */
! 434: #define PULLBYTE() \
! 435: do { \
! 436: if (have == 0) goto inf_leave; \
! 437: have--; \
! 438: hold += (unsigned long)(*next++) << bits; \
! 439: bits += 8; \
! 440: } while (0)
! 441:
! 442: /* Assure that there are at least n bits in the bit accumulator. If there is
! 443: not enough available input to do that, then return from inflate(). */
! 444: #define NEEDBITS(n) \
! 445: do { \
! 446: while (bits < (unsigned)(n)) \
! 447: PULLBYTE(); \
! 448: } while (0)
! 449:
! 450: /* Return the low n bits of the bit accumulator (n < 16) */
! 451: #define BITS(n) \
! 452: ((unsigned)hold & ((1U << (n)) - 1))
! 453:
! 454: /* Remove n bits from the bit accumulator */
! 455: #define DROPBITS(n) \
! 456: do { \
! 457: hold >>= (n); \
! 458: bits -= (unsigned)(n); \
! 459: } while (0)
! 460:
! 461: /* Remove zero to seven bits as needed to go to a byte boundary */
! 462: #define BYTEBITS() \
! 463: do { \
! 464: hold >>= bits & 7; \
! 465: bits -= bits & 7; \
! 466: } while (0)
! 467:
! 468: /* Reverse the bytes in a 32-bit value */
! 469: #define REVERSE(q) \
! 470: ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
! 471: (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
! 472:
! 473: /*
! 474: inflate() uses a state machine to process as much input data and generate as
! 475: much output data as possible before returning. The state machine is
! 476: structured roughly as follows:
! 477:
! 478: for (;;) switch (state) {
! 479: ...
! 480: case STATEn:
! 481: if (not enough input data or output space to make progress)
! 482: return;
! 483: ... make progress ...
! 484: state = STATEm;
! 485: break;
! 486: ...
! 487: }
! 488:
! 489: so when inflate() is called again, the same case is attempted again, and
! 490: if the appropriate resources are provided, the machine proceeds to the
! 491: next state. The NEEDBITS() macro is usually the way the state evaluates
! 492: whether it can proceed or should return. NEEDBITS() does the return if
! 493: the requested bits are not available. The typical use of the BITS macros
! 494: is:
! 495:
! 496: NEEDBITS(n);
! 497: ... do something with BITS(n) ...
! 498: DROPBITS(n);
! 499:
! 500: where NEEDBITS(n) either returns from inflate() if there isn't enough
! 501: input left to load n bits into the accumulator, or it continues. BITS(n)
! 502: gives the low n bits in the accumulator. When done, DROPBITS(n) drops
! 503: the low n bits off the accumulator. INITBITS() clears the accumulator
! 504: and sets the number of available bits to zero. BYTEBITS() discards just
! 505: enough bits to put the accumulator on a byte boundary. After BYTEBITS()
! 506: and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
! 507:
! 508: NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
! 509: if there is no input available. The decoding of variable length codes uses
! 510: PULLBYTE() directly in order to pull just enough bytes to decode the next
! 511: code, and no more.
! 512:
! 513: Some states loop until they get enough input, making sure that enough
! 514: state information is maintained to continue the loop where it left off
! 515: if NEEDBITS() returns in the loop. For example, want, need, and keep
! 516: would all have to actually be part of the saved state in case NEEDBITS()
! 517: returns:
! 518:
! 519: case STATEw:
! 520: while (want < need) {
! 521: NEEDBITS(n);
! 522: keep[want++] = BITS(n);
! 523: DROPBITS(n);
! 524: }
! 525: state = STATEx;
! 526: case STATEx:
! 527:
! 528: As shown above, if the next state is also the next case, then the break
! 529: is omitted.
! 530:
! 531: A state may also return if there is not enough output space available to
! 532: complete that state. Those states are copying stored data, writing a
! 533: literal byte, and copying a matching string.
! 534:
! 535: When returning, a "goto inf_leave" is used to update the total counters,
! 536: update the check value, and determine whether any progress has been made
! 537: during that inflate() call in order to return the proper return code.
! 538: Progress is defined as a change in either strm->avail_in or strm->avail_out.
! 539: When there is a window, goto inf_leave will update the window with the last
! 540: output written. If a goto inf_leave occurs in the middle of decompression
! 541: and there is no window currently, goto inf_leave will create one and copy
! 542: output to the window for the next call of inflate().
! 543:
! 544: In this implementation, the flush parameter of inflate() only affects the
! 545: return code (per zlib.h). inflate() always writes as much as possible to
! 546: strm->next_out, given the space available and the provided input--the effect
! 547: documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
! 548: the allocation of and copying into a sliding window until necessary, which
! 549: provides the effect documented in zlib.h for Z_FINISH when the entire input
! 550: stream available. So the only thing the flush parameter actually does is:
! 551: when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
! 552: will return Z_BUF_ERROR if it has not reached the end of the stream.
! 553: */
! 554:
! 555: int ZEXPORT inflate(strm, flush)
! 556: z_streamp strm;
! 557: int flush;
! 558: {
! 559: struct inflate_state FAR *state;
! 560: unsigned char FAR *next; /* next input */
! 561: unsigned char FAR *put; /* next output */
! 562: unsigned have, left; /* available input and output */
! 563: unsigned long hold; /* bit buffer */
! 564: unsigned bits; /* bits in bit buffer */
! 565: unsigned in, out; /* save starting available input and output */
! 566: unsigned copy; /* number of stored or match bytes to copy */
! 567: unsigned char FAR *from; /* where to copy match bytes from */
! 568: code this; /* current decoding table entry */
! 569: code last; /* parent table entry */
! 570: unsigned len; /* length to copy for repeats, bits to drop */
! 571: int ret; /* return code */
! 572: #ifdef GUNZIP
! 573: unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
! 574: #endif
! 575: static const unsigned short order[19] = /* permutation of code lengths */
! 576: {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
! 577:
! 578: if (strm == Z_NULL || strm->state == Z_NULL ||
! 579: #ifndef __vax__
! 580: strm->next_out == Z_NULL ||
! 581: #endif
! 582: (strm->next_in == Z_NULL && strm->avail_in != 0))
! 583: return Z_STREAM_ERROR;
! 584:
! 585: state = (struct inflate_state FAR *)strm->state;
! 586: if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
! 587: LOAD();
! 588: in = have;
! 589: out = left;
! 590: ret = Z_OK;
! 591: for (;;)
! 592: switch (state->mode) {
! 593: case HEAD:
! 594: if (state->wrap == 0) {
! 595: state->mode = TYPEDO;
! 596: break;
! 597: }
! 598: NEEDBITS(16);
! 599: #ifdef GUNZIP
! 600: if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
! 601: state->check = crc32(0L, Z_NULL, 0);
! 602: CRC2(state->check, hold);
! 603: INITBITS();
! 604: state->mode = FLAGS;
! 605: break;
! 606: }
! 607: state->flags = 0; /* expect zlib header */
! 608: if (state->head != Z_NULL)
! 609: state->head->done = -1;
! 610: if (!(state->wrap & 1) || /* check if zlib header allowed */
! 611: #else
! 612: if (
! 613: #endif
! 614: ((BITS(8) << 8) + (hold >> 8)) % 31) {
! 615: #ifdef SMALL
! 616: strm->msg = "error";
! 617: #else
! 618: strm->msg = (char *)"incorrect header check";
! 619: #endif
! 620: state->mode = BAD;
! 621: break;
! 622: }
! 623: if (BITS(4) != Z_DEFLATED) {
! 624: #ifdef SMALL
! 625: strm->msg = "error";
! 626: #else
! 627: strm->msg = (char *)"unknown compression method";
! 628: #endif
! 629: state->mode = BAD;
! 630: break;
! 631: }
! 632: DROPBITS(4);
! 633: len = BITS(4) + 8;
! 634: if (len > state->wbits) {
! 635: #ifdef SMALL
! 636: strm->msg = "error";
! 637: #else
! 638: strm->msg = (char *)"invalid window size";
! 639: #endif
! 640: state->mode = BAD;
! 641: break;
! 642: }
! 643: state->dmax = 1U << len;
! 644: Tracev((stderr, "inflate: zlib header ok\n"));
! 645: strm->adler = state->check = adler32(0L, Z_NULL, 0);
! 646: state->mode = hold & 0x200 ? DICTID : TYPE;
! 647: INITBITS();
! 648: break;
! 649: #ifdef GUNZIP
! 650: case FLAGS:
! 651: NEEDBITS(16);
! 652: state->flags = (int)(hold);
! 653: if ((state->flags & 0xff) != Z_DEFLATED) {
! 654: #ifdef SMALL
! 655: strm->msg = "error";
! 656: #else
! 657: strm->msg = (char *)"unknown compression method";
! 658: #endif
! 659: state->mode = BAD;
! 660: break;
! 661: }
! 662: if (state->flags & 0xe000) {
! 663: #ifdef SMALL
! 664: strm->msg = "error";
! 665: #else
! 666: strm->msg = (char *)"unknown header flags set";
! 667: #endif
! 668: state->mode = BAD;
! 669: break;
! 670: }
! 671: if (state->head != Z_NULL)
! 672: state->head->text = (int)((hold >> 8) & 1);
! 673: if (state->flags & 0x0200) CRC2(state->check, hold);
! 674: INITBITS();
! 675: state->mode = TIME;
! 676: case TIME:
! 677: NEEDBITS(32);
! 678: if (state->head != Z_NULL)
! 679: state->head->time = hold;
! 680: if (state->flags & 0x0200) CRC4(state->check, hold);
! 681: INITBITS();
! 682: state->mode = OS;
! 683: case OS:
! 684: NEEDBITS(16);
! 685: if (state->head != Z_NULL) {
! 686: state->head->xflags = (int)(hold & 0xff);
! 687: state->head->os = (int)(hold >> 8);
! 688: }
! 689: if (state->flags & 0x0200) CRC2(state->check, hold);
! 690: INITBITS();
! 691: state->mode = EXLEN;
! 692: case EXLEN:
! 693: if (state->flags & 0x0400) {
! 694: NEEDBITS(16);
! 695: state->length = (unsigned)(hold);
! 696: if (state->head != Z_NULL)
! 697: state->head->extra_len = (unsigned)hold;
! 698: if (state->flags & 0x0200) CRC2(state->check, hold);
! 699: INITBITS();
! 700: }
! 701: else if (state->head != Z_NULL)
! 702: state->head->extra = Z_NULL;
! 703: state->mode = EXTRA;
! 704: case EXTRA:
! 705: if (state->flags & 0x0400) {
! 706: copy = state->length;
! 707: if (copy > have) copy = have;
! 708: if (copy) {
! 709: if (state->head != Z_NULL &&
! 710: state->head->extra != Z_NULL) {
! 711: len = state->head->extra_len - state->length;
! 712: zmemcpy(state->head->extra + len, next,
! 713: len + copy > state->head->extra_max ?
! 714: state->head->extra_max - len : copy);
! 715: }
! 716: if (state->flags & 0x0200)
! 717: state->check = crc32(state->check, next, copy);
! 718: have -= copy;
! 719: next += copy;
! 720: state->length -= copy;
! 721: }
! 722: if (state->length) goto inf_leave;
! 723: }
! 724: state->length = 0;
! 725: state->mode = NAME;
! 726: case NAME:
! 727: if (state->flags & 0x0800) {
! 728: if (have == 0) goto inf_leave;
! 729: copy = 0;
! 730: do {
! 731: len = (unsigned)(next[copy++]);
! 732: if (state->head != Z_NULL &&
! 733: state->head->name != Z_NULL &&
! 734: state->length < state->head->name_max)
! 735: state->head->name[state->length++] = len;
! 736: } while (len && copy < have);
! 737: if (state->flags & 0x0200)
! 738: state->check = crc32(state->check, next, copy);
! 739: have -= copy;
! 740: next += copy;
! 741: if (len) goto inf_leave;
! 742: }
! 743: else if (state->head != Z_NULL)
! 744: state->head->name = Z_NULL;
! 745: state->length = 0;
! 746: state->mode = COMMENT;
! 747: case COMMENT:
! 748: if (state->flags & 0x1000) {
! 749: if (have == 0) goto inf_leave;
! 750: copy = 0;
! 751: do {
! 752: len = (unsigned)(next[copy++]);
! 753: if (state->head != Z_NULL &&
! 754: state->head->comment != Z_NULL &&
! 755: state->length < state->head->comm_max)
! 756: state->head->comment[state->length++] = len;
! 757: } while (len && copy < have);
! 758: if (state->flags & 0x0200)
! 759: state->check = crc32(state->check, next, copy);
! 760: have -= copy;
! 761: next += copy;
! 762: if (len) goto inf_leave;
! 763: }
! 764: else if (state->head != Z_NULL)
! 765: state->head->comment = Z_NULL;
! 766: state->mode = HCRC;
! 767: case HCRC:
! 768: if (state->flags & 0x0200) {
! 769: NEEDBITS(16);
! 770: if (hold != (state->check & 0xffff)) {
! 771: #ifdef SMALL
! 772: strm->msg = "error";
! 773: #else
! 774: strm->msg = (char *)"header crc mismatch";
! 775: #endif
! 776: state->mode = BAD;
! 777: break;
! 778: }
! 779: INITBITS();
! 780: }
! 781: if (state->head != Z_NULL) {
! 782: state->head->hcrc = (int)((state->flags >> 9) & 1);
! 783: state->head->done = 1;
! 784: }
! 785: strm->adler = state->check = crc32(0L, Z_NULL, 0);
! 786: state->mode = TYPE;
! 787: break;
! 788: #endif
! 789: case DICTID:
! 790: NEEDBITS(32);
! 791: strm->adler = state->check = REVERSE(hold);
! 792: INITBITS();
! 793: state->mode = DICT;
! 794: case DICT:
! 795: if (state->havedict == 0) {
! 796: RESTORE();
! 797: return Z_NEED_DICT;
! 798: }
! 799: strm->adler = state->check = adler32(0L, Z_NULL, 0);
! 800: state->mode = TYPE;
! 801: case TYPE:
! 802: if (flush == Z_BLOCK) goto inf_leave;
! 803: case TYPEDO:
! 804: if (state->last) {
! 805: BYTEBITS();
! 806: state->mode = CHECK;
! 807: break;
! 808: }
! 809: NEEDBITS(3);
! 810: state->last = BITS(1);
! 811: DROPBITS(1);
! 812: switch (BITS(2)) {
! 813: case 0: /* stored block */
! 814: Tracev((stderr, "inflate: stored block%s\n",
! 815: state->last ? " (last)" : ""));
! 816: state->mode = STORED;
! 817: break;
! 818: case 1: /* fixed block */
! 819: fixedtables(state);
! 820: Tracev((stderr, "inflate: fixed codes block%s\n",
! 821: state->last ? " (last)" : ""));
! 822: state->mode = LEN; /* decode codes */
! 823: break;
! 824: case 2: /* dynamic block */
! 825: Tracev((stderr, "inflate: dynamic codes block%s\n",
! 826: state->last ? " (last)" : ""));
! 827: state->mode = TABLE;
! 828: break;
! 829: case 3:
! 830: #ifdef SMALL
! 831: strm->msg = "error";
! 832: #else
! 833: strm->msg = (char *)"invalid block type";
! 834: #endif
! 835: state->mode = BAD;
! 836: }
! 837: DROPBITS(2);
! 838: break;
! 839: case STORED:
! 840: BYTEBITS(); /* go to byte boundary */
! 841: NEEDBITS(32);
! 842: if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
! 843: #ifdef SMALL
! 844: strm->msg = "error";
! 845: #else
! 846: strm->msg = (char *)"invalid stored block lengths";
! 847: #endif
! 848: state->mode = BAD;
! 849: break;
! 850: }
! 851: state->length = (unsigned)hold & 0xffff;
! 852: Tracev((stderr, "inflate: stored length %u\n",
! 853: state->length));
! 854: INITBITS();
! 855: state->mode = COPY;
! 856: case COPY:
! 857: copy = state->length;
! 858: if (copy) {
! 859: if (copy > have) copy = have;
! 860: if (copy > left) copy = left;
! 861: if (copy == 0) goto inf_leave;
! 862: zmemcpy(put, next, copy);
! 863: have -= copy;
! 864: next += copy;
! 865: left -= copy;
! 866: put += copy;
! 867: state->length -= copy;
! 868: break;
! 869: }
! 870: Tracev((stderr, "inflate: stored end\n"));
! 871: state->mode = TYPE;
! 872: break;
! 873: case TABLE:
! 874: NEEDBITS(14);
! 875: state->nlen = BITS(5) + 257;
! 876: DROPBITS(5);
! 877: state->ndist = BITS(5) + 1;
! 878: DROPBITS(5);
! 879: state->ncode = BITS(4) + 4;
! 880: DROPBITS(4);
! 881: #ifndef PKZIP_BUG_WORKAROUND
! 882: if (state->nlen > 286 || state->ndist > 30) {
! 883: #ifdef SMALL
! 884: strm->msg = "error";
! 885: #else
! 886: strm->msg = (char *)"too many length or distance symbols";
! 887: #endif
! 888: state->mode = BAD;
! 889: break;
! 890: }
! 891: #endif
! 892: Tracev((stderr, "inflate: table sizes ok\n"));
! 893: state->have = 0;
! 894: state->mode = LENLENS;
! 895: case LENLENS:
! 896: while (state->have < state->ncode) {
! 897: NEEDBITS(3);
! 898: state->lens[order[state->have++]] = (unsigned short)BITS(3);
! 899: DROPBITS(3);
! 900: }
! 901: while (state->have < 19)
! 902: state->lens[order[state->have++]] = 0;
! 903: state->next = state->codes;
! 904: state->lencode = (code const FAR *)(state->next);
! 905: state->lenbits = 7;
! 906: ret = inflate_table(CODES, state->lens, 19, &(state->next),
! 907: &(state->lenbits), state->work);
! 908: if (ret) {
! 909: #ifdef SMALL
! 910: strm->msg = "error";
! 911: #else
! 912: strm->msg = (char *)"invalid code lengths set";
! 913: #endif
! 914: state->mode = BAD;
! 915: break;
! 916: }
! 917: Tracev((stderr, "inflate: code lengths ok\n"));
! 918: state->have = 0;
! 919: state->mode = CODELENS;
! 920: case CODELENS:
! 921: while (state->have < state->nlen + state->ndist) {
! 922: for (;;) {
! 923: this = state->lencode[BITS(state->lenbits)];
! 924: if ((unsigned)(this.bits) <= bits) break;
! 925: PULLBYTE();
! 926: }
! 927: if (this.val < 16) {
! 928: NEEDBITS(this.bits);
! 929: DROPBITS(this.bits);
! 930: state->lens[state->have++] = this.val;
! 931: }
! 932: else {
! 933: if (this.val == 16) {
! 934: NEEDBITS(this.bits + 2);
! 935: DROPBITS(this.bits);
! 936: if (state->have == 0) {
! 937: #ifdef SMALL
! 938: strm->msg = "error";
! 939: #else
! 940: strm->msg = (char *)"invalid bit length repeat";
! 941: #endif
! 942: state->mode = BAD;
! 943: break;
! 944: }
! 945: len = state->lens[state->have - 1];
! 946: copy = 3 + BITS(2);
! 947: DROPBITS(2);
! 948: }
! 949: else if (this.val == 17) {
! 950: NEEDBITS(this.bits + 3);
! 951: DROPBITS(this.bits);
! 952: len = 0;
! 953: copy = 3 + BITS(3);
! 954: DROPBITS(3);
! 955: }
! 956: else {
! 957: NEEDBITS(this.bits + 7);
! 958: DROPBITS(this.bits);
! 959: len = 0;
! 960: copy = 11 + BITS(7);
! 961: DROPBITS(7);
! 962: }
! 963: if (state->have + copy > state->nlen + state->ndist) {
! 964: #ifdef SMALL
! 965: strm->msg = "error";
! 966: #else
! 967: strm->msg = (char *)"invalid bit length repeat";
! 968: #endif
! 969: state->mode = BAD;
! 970: break;
! 971: }
! 972: while (copy--)
! 973: state->lens[state->have++] = (unsigned short)len;
! 974: }
! 975: }
! 976:
! 977: /* handle error breaks in while */
! 978: if (state->mode == BAD) break;
! 979:
! 980: /* build code tables */
! 981: state->next = state->codes;
! 982: state->lencode = (code const FAR *)(state->next);
! 983: state->lenbits = 9;
! 984: ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
! 985: &(state->lenbits), state->work);
! 986: if (ret) {
! 987: #ifdef SMALL
! 988: strm->msg = "error";
! 989: #else
! 990: strm->msg = (char *)"invalid literal/lengths set";
! 991: #endif
! 992: state->mode = BAD;
! 993: break;
! 994: }
! 995: state->distcode = (code const FAR *)(state->next);
! 996: state->distbits = 6;
! 997: ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
! 998: &(state->next), &(state->distbits), state->work);
! 999: if (ret) {
! 1000: #ifdef SMALL
! 1001: strm->msg = "error";
! 1002: #else
! 1003: strm->msg = (char *)"invalid distances set";
! 1004: #endif
! 1005: state->mode = BAD;
! 1006: break;
! 1007: }
! 1008: Tracev((stderr, "inflate: codes ok\n"));
! 1009: state->mode = LEN;
! 1010: case LEN:
! 1011: #ifndef SLOW
! 1012: if (have >= 6 && left >= 258) {
! 1013: RESTORE();
! 1014: inflate_fast(strm, out);
! 1015: LOAD();
! 1016: break;
! 1017: }
! 1018: #endif
! 1019: for (;;) {
! 1020: this = state->lencode[BITS(state->lenbits)];
! 1021: if ((unsigned)(this.bits) <= bits) break;
! 1022: PULLBYTE();
! 1023: }
! 1024: if (this.op && (this.op & 0xf0) == 0) {
! 1025: last = this;
! 1026: for (;;) {
! 1027: this = state->lencode[last.val +
! 1028: (BITS(last.bits + last.op) >> last.bits)];
! 1029: if ((unsigned)(last.bits + this.bits) <= bits) break;
! 1030: PULLBYTE();
! 1031: }
! 1032: DROPBITS(last.bits);
! 1033: }
! 1034: DROPBITS(this.bits);
! 1035: state->length = (unsigned)this.val;
! 1036: if ((int)(this.op) == 0) {
! 1037: Tracevv((stderr, this.val >= 0x20 && this.val < 0x7f ?
! 1038: "inflate: literal '%c'\n" :
! 1039: "inflate: literal 0x%02x\n", this.val));
! 1040: state->mode = LIT;
! 1041: break;
! 1042: }
! 1043: if (this.op & 32) {
! 1044: Tracevv((stderr, "inflate: end of block\n"));
! 1045: state->mode = TYPE;
! 1046: break;
! 1047: }
! 1048: if (this.op & 64) {
! 1049: #ifdef SMALL
! 1050: strm->msg = "error";
! 1051: #else
! 1052: strm->msg = (char *)"invalid literal/length code";
! 1053: #endif
! 1054: state->mode = BAD;
! 1055: break;
! 1056: }
! 1057: state->extra = (unsigned)(this.op) & 15;
! 1058: state->mode = LENEXT;
! 1059: case LENEXT:
! 1060: if (state->extra) {
! 1061: NEEDBITS(state->extra);
! 1062: state->length += BITS(state->extra);
! 1063: DROPBITS(state->extra);
! 1064: }
! 1065: Tracevv((stderr, "inflate: length %u\n", state->length));
! 1066: state->mode = DIST;
! 1067: case DIST:
! 1068: for (;;) {
! 1069: this = state->distcode[BITS(state->distbits)];
! 1070: if ((unsigned)(this.bits) <= bits) break;
! 1071: PULLBYTE();
! 1072: }
! 1073: if ((this.op & 0xf0) == 0) {
! 1074: last = this;
! 1075: for (;;) {
! 1076: this = state->distcode[last.val +
! 1077: (BITS(last.bits + last.op) >> last.bits)];
! 1078: if ((unsigned)(last.bits + this.bits) <= bits) break;
! 1079: PULLBYTE();
! 1080: }
! 1081: DROPBITS(last.bits);
! 1082: }
! 1083: DROPBITS(this.bits);
! 1084: if (this.op & 64) {
! 1085: #ifdef SMALL
! 1086: strm->msg = "error";
! 1087: #else
! 1088: strm->msg = (char *)"invalid distance code";
! 1089: #endif
! 1090: state->mode = BAD;
! 1091: break;
! 1092: }
! 1093: state->offset = (unsigned)this.val;
! 1094: state->extra = (unsigned)(this.op) & 15;
! 1095: state->mode = DISTEXT;
! 1096: case DISTEXT:
! 1097: if (state->extra) {
! 1098: NEEDBITS(state->extra);
! 1099: state->offset += BITS(state->extra);
! 1100: DROPBITS(state->extra);
! 1101: }
! 1102: #ifdef INFLATE_STRICT
! 1103: if (state->offset > state->dmax) {
! 1104: strm->msg = (char *)"invalid distance too far back";
! 1105: state->mode = BAD;
! 1106: break;
! 1107: }
! 1108: #endif
! 1109: if (state->offset > state->whave + out - left) {
! 1110: #ifdef SMALL
! 1111: strm->msg = "error";
! 1112: #else
! 1113: strm->msg = (char *)"invalid distance too far back";
! 1114: #endif
! 1115: state->mode = BAD;
! 1116: break;
! 1117: }
! 1118: Tracevv((stderr, "inflate: distance %u\n", state->offset));
! 1119: state->mode = MATCH;
! 1120: case MATCH:
! 1121: if (left == 0) goto inf_leave;
! 1122: copy = out - left;
! 1123: if (state->offset > copy) { /* copy from window */
! 1124: copy = state->offset - copy;
! 1125: if (copy > state->write) {
! 1126: copy -= state->write;
! 1127: from = state->window + (state->wsize - copy);
! 1128: }
! 1129: else
! 1130: from = state->window + (state->write - copy);
! 1131: if (copy > state->length) copy = state->length;
! 1132: }
! 1133: else { /* copy from output */
! 1134: from = put - state->offset;
! 1135: copy = state->length;
! 1136: }
! 1137: if (copy > left) copy = left;
! 1138: left -= copy;
! 1139: state->length -= copy;
! 1140: do {
! 1141: *put++ = *from++;
! 1142: } while (--copy);
! 1143: if (state->length == 0) state->mode = LEN;
! 1144: break;
! 1145: case LIT:
! 1146: if (left == 0) goto inf_leave;
! 1147: *put++ = (unsigned char)(state->length);
! 1148: left--;
! 1149: state->mode = LEN;
! 1150: break;
! 1151: case CHECK:
! 1152: if (state->wrap) {
! 1153: NEEDBITS(32);
! 1154: out -= left;
! 1155: strm->total_out += out;
! 1156: state->total += out;
! 1157: if (out)
! 1158: strm->adler = state->check =
! 1159: UPDATE(state->check, put - out, out);
! 1160: out = left;
! 1161: if ((
! 1162: #ifdef GUNZIP
! 1163: state->flags ? hold :
! 1164: #endif
! 1165: REVERSE(hold)) != state->check) {
! 1166: #ifdef SMALL
! 1167: strm->msg = "error";
! 1168: #else
! 1169: strm->msg = (char *)"incorrect data check";
! 1170: #endif
! 1171: state->mode = BAD;
! 1172: break;
! 1173: }
! 1174: INITBITS();
! 1175: Tracev((stderr, "inflate: check matches trailer\n"));
! 1176: }
! 1177: #ifdef GUNZIP
! 1178: state->mode = LENGTH;
! 1179: case LENGTH:
! 1180: if (state->wrap && state->flags) {
! 1181: NEEDBITS(32);
! 1182: if (hold != (state->total & 0xffffffffUL)) {
! 1183: #ifdef SMALL
! 1184: strm->msg = "error";
! 1185: #else
! 1186: strm->msg = (char *)"incorrect length check";
! 1187: #endif
! 1188: state->mode = BAD;
! 1189: break;
! 1190: }
! 1191: INITBITS();
! 1192: Tracev((stderr, "inflate: length matches trailer\n"));
! 1193: }
! 1194: #endif
! 1195: state->mode = DONE;
! 1196: case DONE:
! 1197: ret = Z_STREAM_END;
! 1198: goto inf_leave;
! 1199: case BAD:
! 1200: ret = Z_DATA_ERROR;
! 1201: goto inf_leave;
! 1202: case MEM:
! 1203: return Z_MEM_ERROR;
! 1204: case SYNC:
! 1205: default:
! 1206: return Z_STREAM_ERROR;
! 1207: }
! 1208:
! 1209: /*
! 1210: Return from inflate(), updating the total counts and the check value.
! 1211: If there was no progress during the inflate() call, return a buffer
! 1212: error. Call updatewindow() to create and/or update the window state.
! 1213: Note: a memory error from inflate() is non-recoverable.
! 1214: */
! 1215: inf_leave:
! 1216: RESTORE();
! 1217: if (state->wsize || (state->mode < CHECK && out != strm->avail_out))
! 1218: if (updatewindow(strm, out)) {
! 1219: state->mode = MEM;
! 1220: return Z_MEM_ERROR;
! 1221: }
! 1222: in -= strm->avail_in;
! 1223: out -= strm->avail_out;
! 1224: strm->total_in += in;
! 1225: strm->total_out += out;
! 1226: state->total += out;
! 1227: if (state->wrap && out)
! 1228: strm->adler = state->check =
! 1229: UPDATE(state->check, strm->next_out - out, out);
! 1230: strm->data_type = state->bits + (state->last ? 64 : 0) +
! 1231: (state->mode == TYPE ? 128 : 0);
! 1232: if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
! 1233: ret = Z_BUF_ERROR;
! 1234: return ret;
! 1235: }
! 1236:
! 1237: int ZEXPORT inflateEnd(strm)
! 1238: z_streamp strm;
! 1239: {
! 1240: struct inflate_state FAR *state;
! 1241: if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
! 1242: return Z_STREAM_ERROR;
! 1243: state = (struct inflate_state FAR *)strm->state;
! 1244: if (state->window != Z_NULL) ZFREE(strm, state->window);
! 1245: ZFREE(strm, strm->state);
! 1246: strm->state = Z_NULL;
! 1247: Tracev((stderr, "inflate: end\n"));
! 1248: return Z_OK;
! 1249: }
! 1250:
! 1251: int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
! 1252: z_streamp strm;
! 1253: const Bytef *dictionary;
! 1254: uInt dictLength;
! 1255: {
! 1256: struct inflate_state FAR *state;
! 1257: unsigned long id;
! 1258:
! 1259: /* check state */
! 1260: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
! 1261: state = (struct inflate_state FAR *)strm->state;
! 1262: if (state->wrap != 0 && state->mode != DICT)
! 1263: return Z_STREAM_ERROR;
! 1264:
! 1265: /* check for correct dictionary id */
! 1266: if (state->mode == DICT) {
! 1267: id = adler32(0L, Z_NULL, 0);
! 1268: id = adler32(id, dictionary, dictLength);
! 1269: if (id != state->check)
! 1270: return Z_DATA_ERROR;
! 1271: }
! 1272:
! 1273: /* copy dictionary to window */
! 1274: if (updatewindow(strm, strm->avail_out)) {
! 1275: state->mode = MEM;
! 1276: return Z_MEM_ERROR;
! 1277: }
! 1278: if (dictLength > state->wsize) {
! 1279: zmemcpy(state->window, dictionary + dictLength - state->wsize,
! 1280: state->wsize);
! 1281: state->whave = state->wsize;
! 1282: }
! 1283: else {
! 1284: zmemcpy(state->window + state->wsize - dictLength, dictionary,
! 1285: dictLength);
! 1286: state->whave = dictLength;
! 1287: }
! 1288: state->havedict = 1;
! 1289: Tracev((stderr, "inflate: dictionary set\n"));
! 1290: return Z_OK;
! 1291: }
! 1292:
! 1293: int ZEXPORT inflateGetHeader(strm, head)
! 1294: z_streamp strm;
! 1295: gz_headerp head;
! 1296: {
! 1297: struct inflate_state FAR *state;
! 1298:
! 1299: /* check state */
! 1300: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
! 1301: state = (struct inflate_state FAR *)strm->state;
! 1302: if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
! 1303:
! 1304: /* save header structure */
! 1305: state->head = head;
! 1306: head->done = 0;
! 1307: return Z_OK;
! 1308: }
! 1309:
! 1310: /*
! 1311: Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found
! 1312: or when out of input. When called, *have is the number of pattern bytes
! 1313: found in order so far, in 0..3. On return *have is updated to the new
! 1314: state. If on return *have equals four, then the pattern was found and the
! 1315: return value is how many bytes were read including the last byte of the
! 1316: pattern. If *have is less than four, then the pattern has not been found
! 1317: yet and the return value is len. In the latter case, syncsearch() can be
! 1318: called again with more data and the *have state. *have is initialized to
! 1319: zero for the first call.
! 1320: */
! 1321: local unsigned syncsearch(have, buf, len)
! 1322: unsigned FAR *have;
! 1323: unsigned char FAR *buf;
! 1324: unsigned len;
! 1325: {
! 1326: unsigned got;
! 1327: unsigned next;
! 1328:
! 1329: got = *have;
! 1330: next = 0;
! 1331: while (next < len && got < 4) {
! 1332: if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
! 1333: got++;
! 1334: else if (buf[next])
! 1335: got = 0;
! 1336: else
! 1337: got = 4 - got;
! 1338: next++;
! 1339: }
! 1340: *have = got;
! 1341: return next;
! 1342: }
! 1343:
! 1344: int ZEXPORT inflateSync(strm)
! 1345: z_streamp strm;
! 1346: {
! 1347: unsigned len; /* number of bytes to look at or looked at */
! 1348: unsigned long in, out; /* temporary to save total_in and total_out */
! 1349: unsigned char buf[4]; /* to restore bit buffer to byte string */
! 1350: struct inflate_state FAR *state;
! 1351:
! 1352: /* check parameters */
! 1353: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
! 1354: state = (struct inflate_state FAR *)strm->state;
! 1355: if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
! 1356:
! 1357: /* if first time, start search in bit buffer */
! 1358: if (state->mode != SYNC) {
! 1359: state->mode = SYNC;
! 1360: state->hold <<= state->bits & 7;
! 1361: state->bits -= state->bits & 7;
! 1362: len = 0;
! 1363: while (state->bits >= 8) {
! 1364: buf[len++] = (unsigned char)(state->hold);
! 1365: state->hold >>= 8;
! 1366: state->bits -= 8;
! 1367: }
! 1368: state->have = 0;
! 1369: syncsearch(&(state->have), buf, len);
! 1370: }
! 1371:
! 1372: /* search available input */
! 1373: len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
! 1374: strm->avail_in -= len;
! 1375: strm->next_in += len;
! 1376: strm->total_in += len;
! 1377:
! 1378: /* return no joy or set up to restart inflate() on a new block */
! 1379: if (state->have != 4) return Z_DATA_ERROR;
! 1380: in = strm->total_in; out = strm->total_out;
! 1381: inflateReset(strm);
! 1382: strm->total_in = in; strm->total_out = out;
! 1383: state->mode = TYPE;
! 1384: return Z_OK;
! 1385: }
! 1386:
! 1387: /*
! 1388: Returns true if inflate is currently at the end of a block generated by
! 1389: Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
! 1390: implementation to provide an additional safety check. PPP uses
! 1391: Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
! 1392: block. When decompressing, PPP checks that at the end of input packet,
! 1393: inflate is waiting for these length bytes.
! 1394: */
! 1395: int ZEXPORT inflateSyncPoint(strm)
! 1396: z_streamp strm;
! 1397: {
! 1398: struct inflate_state FAR *state;
! 1399:
! 1400: if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
! 1401: state = (struct inflate_state FAR *)strm->state;
! 1402: return state->mode == STORED && state->bits == 0;
! 1403: }
! 1404:
! 1405: int ZEXPORT inflateCopy(dest, source)
! 1406: z_streamp dest;
! 1407: z_streamp source;
! 1408: {
! 1409: struct inflate_state FAR *state;
! 1410: struct inflate_state FAR *copy;
! 1411: unsigned char FAR *window;
! 1412: unsigned wsize;
! 1413:
! 1414: /* check input */
! 1415: if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL ||
! 1416: source->zalloc == (alloc_func)0 || source->zfree == (free_func)0)
! 1417: return Z_STREAM_ERROR;
! 1418: state = (struct inflate_state FAR *)source->state;
! 1419:
! 1420: /* allocate space */
! 1421: copy = (struct inflate_state FAR *)
! 1422: ZALLOC(source, 1, sizeof(struct inflate_state));
! 1423: if (copy == Z_NULL) return Z_MEM_ERROR;
! 1424: window = Z_NULL;
! 1425: if (state->window != Z_NULL) {
! 1426: window = (unsigned char FAR *)
! 1427: ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
! 1428: if (window == Z_NULL) {
! 1429: ZFREE(source, copy);
! 1430: return Z_MEM_ERROR;
! 1431: }
! 1432: }
! 1433:
! 1434: /* copy state */
! 1435: zmemcpy(dest, source, sizeof(z_stream));
! 1436: zmemcpy(copy, state, sizeof(struct inflate_state));
! 1437: if (state->lencode >= state->codes &&
! 1438: state->lencode <= state->codes + ENOUGH - 1) {
! 1439: copy->lencode = copy->codes + (state->lencode - state->codes);
! 1440: copy->distcode = copy->codes + (state->distcode - state->codes);
! 1441: }
! 1442: copy->next = copy->codes + (state->next - state->codes);
! 1443: if (window != Z_NULL) {
! 1444: wsize = 1U << state->wbits;
! 1445: zmemcpy(window, state->window, wsize);
! 1446: }
! 1447: copy->window = window;
! 1448: dest->state = (struct internal_state FAR *)copy;
! 1449: return Z_OK;
! 1450: }
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