diff options
Diffstat (limited to 'libs/zlib/src/inflate.c')
| -rw-r--r-- | libs/zlib/src/inflate.c | 3187 |
1 files changed, 1595 insertions, 1592 deletions
diff --git a/libs/zlib/src/inflate.c b/libs/zlib/src/inflate.c index 7be8c63662..34120021b6 100644 --- a/libs/zlib/src/inflate.c +++ b/libs/zlib/src/inflate.c @@ -1,1592 +1,1595 @@ -/* inflate.c -- zlib decompression - * Copyright (C) 1995-2022 Mark Adler - * For conditions of distribution and use, see copyright notice in zlib.h - */ - -/* - * Change history: - * - * 1.2.beta0 24 Nov 2002 - * - First version -- complete rewrite of inflate to simplify code, avoid - * creation of window when not needed, minimize use of window when it is - * needed, make inffast.c even faster, implement gzip decoding, and to - * improve code readability and style over the previous zlib inflate code - * - * 1.2.beta1 25 Nov 2002 - * - Use pointers for available input and output checking in inffast.c - * - Remove input and output counters in inffast.c - * - Change inffast.c entry and loop from avail_in >= 7 to >= 6 - * - Remove unnecessary second byte pull from length extra in inffast.c - * - Unroll direct copy to three copies per loop in inffast.c - * - * 1.2.beta2 4 Dec 2002 - * - Change external routine names to reduce potential conflicts - * - Correct filename to inffixed.h for fixed tables in inflate.c - * - Make hbuf[] unsigned char to match parameter type in inflate.c - * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset) - * to avoid negation problem on Alphas (64 bit) in inflate.c - * - * 1.2.beta3 22 Dec 2002 - * - Add comments on state->bits assertion in inffast.c - * - Add comments on op field in inftrees.h - * - Fix bug in reuse of allocated window after inflateReset() - * - Remove bit fields--back to byte structure for speed - * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths - * - Change post-increments to pre-increments in inflate_fast(), PPC biased? - * - Add compile time option, POSTINC, to use post-increments instead (Intel?) - * - Make MATCH copy in inflate() much faster for when inflate_fast() not used - * - Use local copies of stream next and avail values, as well as local bit - * buffer and bit count in inflate()--for speed when inflate_fast() not used - * - * 1.2.beta4 1 Jan 2003 - * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings - * - Move a comment on output buffer sizes from inffast.c to inflate.c - * - Add comments in inffast.c to introduce the inflate_fast() routine - * - Rearrange window copies in inflate_fast() for speed and simplification - * - Unroll last copy for window match in inflate_fast() - * - Use local copies of window variables in inflate_fast() for speed - * - Pull out common wnext == 0 case for speed in inflate_fast() - * - Make op and len in inflate_fast() unsigned for consistency - * - Add FAR to lcode and dcode declarations in inflate_fast() - * - Simplified bad distance check in inflate_fast() - * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new - * source file infback.c to provide a call-back interface to inflate for - * programs like gzip and unzip -- uses window as output buffer to avoid - * window copying - * - * 1.2.beta5 1 Jan 2003 - * - Improved inflateBack() interface to allow the caller to provide initial - * input in strm. - * - Fixed stored blocks bug in inflateBack() - * - * 1.2.beta6 4 Jan 2003 - * - Added comments in inffast.c on effectiveness of POSTINC - * - Typecasting all around to reduce compiler warnings - * - Changed loops from while (1) or do {} while (1) to for (;;), again to - * make compilers happy - * - Changed type of window in inflateBackInit() to unsigned char * - * - * 1.2.beta7 27 Jan 2003 - * - Changed many types to unsigned or unsigned short to avoid warnings - * - Added inflateCopy() function - * - * 1.2.0 9 Mar 2003 - * - Changed inflateBack() interface to provide separate opaque descriptors - * for the in() and out() functions - * - Changed inflateBack() argument and in_func typedef to swap the length - * and buffer address return values for the input function - * - Check next_in and next_out for Z_NULL on entry to inflate() - * - * The history for versions after 1.2.0 are in ChangeLog in zlib distribution. - */ - -#include "zutil.h" -#include "inftrees.h" -#include "inflate.h" -#include "inffast.h" - -#ifdef MAKEFIXED -# ifndef BUILDFIXED -# define BUILDFIXED -# endif -#endif - -/* function prototypes */ -local int inflateStateCheck OF((z_streamp strm)); -local void fixedtables OF((struct inflate_state FAR *state)); -local int updatewindow OF((z_streamp strm, const unsigned char FAR *end, - unsigned copy)); -#ifdef BUILDFIXED - void makefixed OF((void)); -#endif -local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf, - unsigned len)); - -local int inflateStateCheck(strm) -z_streamp strm; -{ - struct inflate_state FAR *state; - if (strm == Z_NULL || - strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0) - return 1; - state = (struct inflate_state FAR *)strm->state; - if (state == Z_NULL || state->strm != strm || - state->mode < HEAD || state->mode > SYNC) - return 1; - return 0; -} - -int ZEXPORT inflateResetKeep(strm) -z_streamp strm; -{ - struct inflate_state FAR *state; - - if (inflateStateCheck(strm)) return Z_STREAM_ERROR; - state = (struct inflate_state FAR *)strm->state; - strm->total_in = strm->total_out = state->total = 0; - strm->msg = Z_NULL; - if (state->wrap) /* to support ill-conceived Java test suite */ - strm->adler = state->wrap & 1; - state->mode = HEAD; - state->last = 0; - state->havedict = 0; - state->flags = -1; - state->dmax = 32768U; - state->head = Z_NULL; - state->hold = 0; - state->bits = 0; - state->lencode = state->distcode = state->next = state->codes; - state->sane = 1; - state->back = -1; - Tracev((stderr, "inflate: reset\n")); - return Z_OK; -} - -int ZEXPORT inflateReset(strm) -z_streamp strm; -{ - struct inflate_state FAR *state; - - if (inflateStateCheck(strm)) return Z_STREAM_ERROR; - state = (struct inflate_state FAR *)strm->state; - state->wsize = 0; - state->whave = 0; - state->wnext = 0; - return inflateResetKeep(strm); -} - -int ZEXPORT inflateReset2(strm, windowBits) -z_streamp strm; -int windowBits; -{ - int wrap; - struct inflate_state FAR *state; - - /* get the state */ - if (inflateStateCheck(strm)) return Z_STREAM_ERROR; - state = (struct inflate_state FAR *)strm->state; - - /* extract wrap request from windowBits parameter */ - if (windowBits < 0) { - wrap = 0; - windowBits = -windowBits; - } - else { - wrap = (windowBits >> 4) + 5; -#ifdef GUNZIP - if (windowBits < 48) - windowBits &= 15; -#endif - } - - /* set number of window bits, free window if different */ - if (windowBits && (windowBits < 8 || windowBits > 15)) - return Z_STREAM_ERROR; - if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) { - ZFREE(strm, state->window); - state->window = Z_NULL; - } - - /* update state and reset the rest of it */ - state->wrap = wrap; - state->wbits = (unsigned)windowBits; - return inflateReset(strm); -} - -int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size) -z_streamp strm; -int windowBits; -const char *version; -int stream_size; -{ - int ret; - struct inflate_state FAR *state; - - if (version == Z_NULL || version[0] != ZLIB_VERSION[0] || - stream_size != (int)(sizeof(z_stream))) - return Z_VERSION_ERROR; - if (strm == Z_NULL) return Z_STREAM_ERROR; - strm->msg = Z_NULL; /* in case we return an error */ - if (strm->zalloc == (alloc_func)0) { -#ifdef Z_SOLO - return Z_STREAM_ERROR; -#else - strm->zalloc = zcalloc; - strm->opaque = (voidpf)0; -#endif - } - if (strm->zfree == (free_func)0) -#ifdef Z_SOLO - return Z_STREAM_ERROR; -#else - strm->zfree = zcfree; -#endif - state = (struct inflate_state FAR *) - ZALLOC(strm, 1, sizeof(struct inflate_state)); - if (state == Z_NULL) return Z_MEM_ERROR; - Tracev((stderr, "inflate: allocated\n")); - strm->state = (struct internal_state FAR *)state; - state->strm = strm; - state->window = Z_NULL; - state->mode = HEAD; /* to pass state test in inflateReset2() */ - ret = inflateReset2(strm, windowBits); - if (ret != Z_OK) { - ZFREE(strm, state); - strm->state = Z_NULL; - } - return ret; -} - -int ZEXPORT inflateInit_(strm, version, stream_size) -z_streamp strm; -const char *version; -int stream_size; -{ - return inflateInit2_(strm, DEF_WBITS, version, stream_size); -} - -int ZEXPORT inflatePrime(strm, bits, value) -z_streamp strm; -int bits; -int value; -{ - struct inflate_state FAR *state; - - if (inflateStateCheck(strm)) return Z_STREAM_ERROR; - state = (struct inflate_state FAR *)strm->state; - if (bits < 0) { - state->hold = 0; - state->bits = 0; - return Z_OK; - } - if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR; - value &= (1L << bits) - 1; - state->hold += (unsigned)value << state->bits; - state->bits += (uInt)bits; - return Z_OK; -} - -/* - Return state with length and distance decoding tables and index sizes set to - fixed code decoding. Normally this returns fixed tables from inffixed.h. - If BUILDFIXED is defined, then instead this routine builds the tables the - first time it's called, and returns those tables the first time and - thereafter. This reduces the size of the code by about 2K bytes, in - exchange for a little execution time. However, BUILDFIXED should not be - used for threaded applications, since the rewriting of the tables and virgin - may not be thread-safe. - */ -local void fixedtables(state) -struct inflate_state FAR *state; -{ -#ifdef BUILDFIXED - static int virgin = 1; - static code *lenfix, *distfix; - static code fixed[544]; - - /* build fixed huffman tables if first call (may not be thread safe) */ - if (virgin) { - unsigned sym, bits; - static code *next; - - /* literal/length table */ - sym = 0; - while (sym < 144) state->lens[sym++] = 8; - while (sym < 256) state->lens[sym++] = 9; - while (sym < 280) state->lens[sym++] = 7; - while (sym < 288) state->lens[sym++] = 8; - next = fixed; - lenfix = next; - bits = 9; - inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work); - - /* distance table */ - sym = 0; - while (sym < 32) state->lens[sym++] = 5; - distfix = next; - bits = 5; - inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work); - - /* do this just once */ - virgin = 0; - } -#else /* !BUILDFIXED */ -# include "inffixed.h" -#endif /* BUILDFIXED */ - state->lencode = lenfix; - state->lenbits = 9; - state->distcode = distfix; - state->distbits = 5; -} - -#ifdef MAKEFIXED -#include <stdio.h> - -/* - Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also - defines BUILDFIXED, so the tables are built on the fly. makefixed() writes - those tables to stdout, which would be piped to inffixed.h. A small program - can simply call makefixed to do this: - - void makefixed(void); - - int main(void) - { - makefixed(); - return 0; - } - - Then that can be linked with zlib built with MAKEFIXED defined and run: - - a.out > inffixed.h - */ -void makefixed() -{ - unsigned low, size; - struct inflate_state state; - - fixedtables(&state); - puts(" /* inffixed.h -- table for decoding fixed codes"); - puts(" * Generated automatically by makefixed()."); - puts(" */"); - puts(""); - puts(" /* WARNING: this file should *not* be used by applications."); - puts(" It is part of the implementation of this library and is"); - puts(" subject to change. Applications should only use zlib.h."); - puts(" */"); - puts(""); - size = 1U << 9; - printf(" static const code lenfix[%u] = {", size); - low = 0; - for (;;) { - if ((low % 7) == 0) printf("\n "); - printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op, - state.lencode[low].bits, state.lencode[low].val); - if (++low == size) break; - putchar(','); - } - puts("\n };"); - size = 1U << 5; - printf("\n static const code distfix[%u] = {", size); - low = 0; - for (;;) { - if ((low % 6) == 0) printf("\n "); - printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits, - state.distcode[low].val); - if (++low == size) break; - putchar(','); - } - puts("\n };"); -} -#endif /* MAKEFIXED */ - -/* - Update the window with the last wsize (normally 32K) bytes written before - returning. If window does not exist yet, create it. This is only called - when a window is already in use, or when output has been written during this - inflate call, but the end of the deflate stream has not been reached yet. - It is also called to create a window for dictionary data when a dictionary - is loaded. - - Providing output buffers larger than 32K to inflate() should provide a speed - advantage, since only the last 32K of output is copied to the sliding window - upon return from inflate(), and since all distances after the first 32K of - output will fall in the output data, making match copies simpler and faster. - The advantage may be dependent on the size of the processor's data caches. - */ -local int updatewindow(strm, end, copy) -z_streamp strm; -const Bytef *end; -unsigned copy; -{ - struct inflate_state FAR *state; - unsigned dist; - - state = (struct inflate_state FAR *)strm->state; - - /* if it hasn't been done already, allocate space for the window */ - if (state->window == Z_NULL) { - state->window = (unsigned char FAR *) - ZALLOC(strm, 1U << state->wbits, - sizeof(unsigned char)); - if (state->window == Z_NULL) return 1; - } - - /* if window not in use yet, initialize */ - if (state->wsize == 0) { - state->wsize = 1U << state->wbits; - state->wnext = 0; - state->whave = 0; - } - - /* copy state->wsize or less output bytes into the circular window */ - if (copy >= state->wsize) { - zmemcpy(state->window, end - state->wsize, state->wsize); - state->wnext = 0; - state->whave = state->wsize; - } - else { - dist = state->wsize - state->wnext; - if (dist > copy) dist = copy; - zmemcpy(state->window + state->wnext, end - copy, dist); - copy -= dist; - if (copy) { - zmemcpy(state->window, end - copy, copy); - state->wnext = copy; - state->whave = state->wsize; - } - else { - state->wnext += dist; - if (state->wnext == state->wsize) state->wnext = 0; - if (state->whave < state->wsize) state->whave += dist; - } - } - return 0; -} - -/* Macros for inflate(): */ - -/* check function to use adler32() for zlib or crc32() for gzip */ -#ifdef GUNZIP -# define UPDATE_CHECK(check, buf, len) \ - (state->flags ? crc32(check, buf, len) : adler32(check, buf, len)) -#else -# define UPDATE_CHECK(check, buf, len) adler32(check, buf, len) -#endif - -/* check macros for header crc */ -#ifdef GUNZIP -# define CRC2(check, word) \ - do { \ - hbuf[0] = (unsigned char)(word); \ - hbuf[1] = (unsigned char)((word) >> 8); \ - check = crc32(check, hbuf, 2); \ - } while (0) - -# define CRC4(check, word) \ - do { \ - hbuf[0] = (unsigned char)(word); \ - hbuf[1] = (unsigned char)((word) >> 8); \ - hbuf[2] = (unsigned char)((word) >> 16); \ - hbuf[3] = (unsigned char)((word) >> 24); \ - check = crc32(check, hbuf, 4); \ - } while (0) -#endif - -/* Load registers with state in inflate() for speed */ -#define LOAD() \ - do { \ - put = strm->next_out; \ - left = strm->avail_out; \ - next = strm->next_in; \ - have = strm->avail_in; \ - hold = state->hold; \ - bits = state->bits; \ - } while (0) - -/* Restore state from registers in inflate() */ -#define RESTORE() \ - do { \ - strm->next_out = put; \ - strm->avail_out = left; \ - strm->next_in = next; \ - strm->avail_in = have; \ - state->hold = hold; \ - state->bits = bits; \ - } while (0) - -/* Clear the input bit accumulator */ -#define INITBITS() \ - do { \ - hold = 0; \ - bits = 0; \ - } while (0) - -/* Get a byte of input into the bit accumulator, or return from inflate() - if there is no input available. */ -#define PULLBYTE() \ - do { \ - if (have == 0) goto inf_leave; \ - have--; \ - hold += (unsigned long)(*next++) << bits; \ - bits += 8; \ - } while (0) - -/* Assure that there are at least n bits in the bit accumulator. If there is - not enough available input to do that, then return from inflate(). */ -#define NEEDBITS(n) \ - do { \ - while (bits < (unsigned)(n)) \ - PULLBYTE(); \ - } while (0) - -/* Return the low n bits of the bit accumulator (n < 16) */ -#define BITS(n) \ - ((unsigned)hold & ((1U << (n)) - 1)) - -/* Remove n bits from the bit accumulator */ -#define DROPBITS(n) \ - do { \ - hold >>= (n); \ - bits -= (unsigned)(n); \ - } while (0) - -/* Remove zero to seven bits as needed to go to a byte boundary */ -#define BYTEBITS() \ - do { \ - hold >>= bits & 7; \ - bits -= bits & 7; \ - } while (0) - -/* - inflate() uses a state machine to process as much input data and generate as - much output data as possible before returning. The state machine is - structured roughly as follows: - - for (;;) switch (state) { - ... - case STATEn: - if (not enough input data or output space to make progress) - return; - ... make progress ... - state = STATEm; - break; - ... - } - - so when inflate() is called again, the same case is attempted again, and - if the appropriate resources are provided, the machine proceeds to the - next state. The NEEDBITS() macro is usually the way the state evaluates - whether it can proceed or should return. NEEDBITS() does the return if - the requested bits are not available. The typical use of the BITS macros - is: - - NEEDBITS(n); - ... do something with BITS(n) ... - DROPBITS(n); - - where NEEDBITS(n) either returns from inflate() if there isn't enough - input left to load n bits into the accumulator, or it continues. BITS(n) - gives the low n bits in the accumulator. When done, DROPBITS(n) drops - the low n bits off the accumulator. INITBITS() clears the accumulator - and sets the number of available bits to zero. BYTEBITS() discards just - enough bits to put the accumulator on a byte boundary. After BYTEBITS() - and a NEEDBITS(8), then BITS(8) would return the next byte in the stream. - - NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return - if there is no input available. The decoding of variable length codes uses - PULLBYTE() directly in order to pull just enough bytes to decode the next - code, and no more. - - Some states loop until they get enough input, making sure that enough - state information is maintained to continue the loop where it left off - if NEEDBITS() returns in the loop. For example, want, need, and keep - would all have to actually be part of the saved state in case NEEDBITS() - returns: - - case STATEw: - while (want < need) { - NEEDBITS(n); - keep[want++] = BITS(n); - DROPBITS(n); - } - state = STATEx; - case STATEx: - - As shown above, if the next state is also the next case, then the break - is omitted. - - A state may also return if there is not enough output space available to - complete that state. Those states are copying stored data, writing a - literal byte, and copying a matching string. - - When returning, a "goto inf_leave" is used to update the total counters, - update the check value, and determine whether any progress has been made - during that inflate() call in order to return the proper return code. - Progress is defined as a change in either strm->avail_in or strm->avail_out. - When there is a window, goto inf_leave will update the window with the last - output written. If a goto inf_leave occurs in the middle of decompression - and there is no window currently, goto inf_leave will create one and copy - output to the window for the next call of inflate(). - - In this implementation, the flush parameter of inflate() only affects the - return code (per zlib.h). inflate() always writes as much as possible to - strm->next_out, given the space available and the provided input--the effect - documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers - the allocation of and copying into a sliding window until necessary, which - provides the effect documented in zlib.h for Z_FINISH when the entire input - stream available. So the only thing the flush parameter actually does is: - when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it - will return Z_BUF_ERROR if it has not reached the end of the stream. - */ - -int ZEXPORT inflate(strm, flush) -z_streamp strm; -int flush; -{ - struct inflate_state FAR *state; - z_const unsigned char FAR *next; /* next input */ - unsigned char FAR *put; /* next output */ - unsigned have, left; /* available input and output */ - unsigned long hold; /* bit buffer */ - unsigned bits; /* bits in bit buffer */ - unsigned in, out; /* save starting available input and output */ - unsigned copy; /* number of stored or match bytes to copy */ - unsigned char FAR *from; /* where to copy match bytes from */ - code here; /* current decoding table entry */ - code last; /* parent table entry */ - unsigned len; /* length to copy for repeats, bits to drop */ - int ret; /* return code */ -#ifdef GUNZIP - unsigned char hbuf[4]; /* buffer for gzip header crc calculation */ -#endif - static const unsigned short order[19] = /* permutation of code lengths */ - {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; - - if (inflateStateCheck(strm) || strm->next_out == Z_NULL || - (strm->next_in == Z_NULL && strm->avail_in != 0)) - return Z_STREAM_ERROR; - - state = (struct inflate_state FAR *)strm->state; - if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */ - LOAD(); - in = have; - out = left; - ret = Z_OK; - for (;;) - switch (state->mode) { - case HEAD: - if (state->wrap == 0) { - state->mode = TYPEDO; - break; - } - NEEDBITS(16); -#ifdef GUNZIP - if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */ - if (state->wbits == 0) - state->wbits = 15; - state->check = crc32(0L, Z_NULL, 0); - CRC2(state->check, hold); - INITBITS(); - state->mode = FLAGS; - break; - } - if (state->head != Z_NULL) - state->head->done = -1; - if (!(state->wrap & 1) || /* check if zlib header allowed */ -#else - if ( -#endif - ((BITS(8) << 8) + (hold >> 8)) % 31) { - strm->msg = (char *)"incorrect header check"; - state->mode = BAD; - break; - } - if (BITS(4) != Z_DEFLATED) { - strm->msg = (char *)"unknown compression method"; - state->mode = BAD; - break; - } - DROPBITS(4); - len = BITS(4) + 8; - if (state->wbits == 0) - state->wbits = len; - if (len > 15 || len > state->wbits) { - strm->msg = (char *)"invalid window size"; - state->mode = BAD; - break; - } - state->dmax = 1U << len; - state->flags = 0; /* indicate zlib header */ - Tracev((stderr, "inflate: zlib header ok\n")); - strm->adler = state->check = adler32(0L, Z_NULL, 0); - state->mode = hold & 0x200 ? DICTID : TYPE; - INITBITS(); - break; -#ifdef GUNZIP - case FLAGS: - NEEDBITS(16); - state->flags = (int)(hold); - if ((state->flags & 0xff) != Z_DEFLATED) { - strm->msg = (char *)"unknown compression method"; - state->mode = BAD; - break; - } - if (state->flags & 0xe000) { - strm->msg = (char *)"unknown header flags set"; - state->mode = BAD; - break; - } - if (state->head != Z_NULL) - state->head->text = (int)((hold >> 8) & 1); - if ((state->flags & 0x0200) && (state->wrap & 4)) - CRC2(state->check, hold); - INITBITS(); - state->mode = TIME; - /* fallthrough */ - case TIME: - NEEDBITS(32); - if (state->head != Z_NULL) - state->head->time = hold; - if ((state->flags & 0x0200) && (state->wrap & 4)) - CRC4(state->check, hold); - INITBITS(); - state->mode = OS; - /* fallthrough */ - case OS: - NEEDBITS(16); - if (state->head != Z_NULL) { - state->head->xflags = (int)(hold & 0xff); - state->head->os = (int)(hold >> 8); - } - if ((state->flags & 0x0200) && (state->wrap & 4)) - CRC2(state->check, hold); - INITBITS(); - state->mode = EXLEN; - /* fallthrough */ - case EXLEN: - if (state->flags & 0x0400) { - NEEDBITS(16); - state->length = (unsigned)(hold); - if (state->head != Z_NULL) - state->head->extra_len = (unsigned)hold; - if ((state->flags & 0x0200) && (state->wrap & 4)) - CRC2(state->check, hold); - INITBITS(); - } - else if (state->head != Z_NULL) - state->head->extra = Z_NULL; - state->mode = EXTRA; - /* fallthrough */ - case EXTRA: - if (state->flags & 0x0400) { - copy = state->length; - if (copy > have) copy = have; - if (copy) { - if (state->head != Z_NULL && - state->head->extra != Z_NULL) { - len = state->head->extra_len - state->length; - zmemcpy(state->head->extra + len, next, - len + copy > state->head->extra_max ? - state->head->extra_max - len : copy); - } - if ((state->flags & 0x0200) && (state->wrap & 4)) - state->check = crc32(state->check, next, copy); - have -= copy; - next += copy; - state->length -= copy; - } - if (state->length) goto inf_leave; - } - state->length = 0; - state->mode = NAME; - /* fallthrough */ - case NAME: - if (state->flags & 0x0800) { - if (have == 0) goto inf_leave; - copy = 0; - do { - len = (unsigned)(next[copy++]); - if (state->head != Z_NULL && - state->head->name != Z_NULL && - state->length < state->head->name_max) - state->head->name[state->length++] = (Bytef)len; - } while (len && copy < have); - if ((state->flags & 0x0200) && (state->wrap & 4)) - state->check = crc32(state->check, next, copy); - have -= copy; - next += copy; - if (len) goto inf_leave; - } - else if (state->head != Z_NULL) - state->head->name = Z_NULL; - state->length = 0; - state->mode = COMMENT; - /* fallthrough */ - case COMMENT: - if (state->flags & 0x1000) { - if (have == 0) goto inf_leave; - copy = 0; - do { - len = (unsigned)(next[copy++]); - if (state->head != Z_NULL && - state->head->comment != Z_NULL && - state->length < state->head->comm_max) - state->head->comment[state->length++] = (Bytef)len; - } while (len && copy < have); - if ((state->flags & 0x0200) && (state->wrap & 4)) - state->check = crc32(state->check, next, copy); - have -= copy; - next += copy; - if (len) goto inf_leave; - } - else if (state->head != Z_NULL) - state->head->comment = Z_NULL; - state->mode = HCRC; - /* fallthrough */ - case HCRC: - if (state->flags & 0x0200) { - NEEDBITS(16); - if ((state->wrap & 4) && hold != (state->check & 0xffff)) { - strm->msg = (char *)"header crc mismatch"; - state->mode = BAD; - break; - } - INITBITS(); - } - if (state->head != Z_NULL) { - state->head->hcrc = (int)((state->flags >> 9) & 1); - state->head->done = 1; - } - strm->adler = state->check = crc32(0L, Z_NULL, 0); - state->mode = TYPE; - break; -#endif - case DICTID: - NEEDBITS(32); - strm->adler = state->check = ZSWAP32(hold); - INITBITS(); - state->mode = DICT; - /* fallthrough */ - case DICT: - if (state->havedict == 0) { - RESTORE(); - return Z_NEED_DICT; - } - strm->adler = state->check = adler32(0L, Z_NULL, 0); - state->mode = TYPE; - /* fallthrough */ - case TYPE: - if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave; - /* fallthrough */ - case TYPEDO: - if (state->last) { - BYTEBITS(); - state->mode = CHECK; - break; - } - NEEDBITS(3); - state->last = BITS(1); - DROPBITS(1); - switch (BITS(2)) { - case 0: /* stored block */ - Tracev((stderr, "inflate: stored block%s\n", - state->last ? " (last)" : "")); - state->mode = STORED; - break; - case 1: /* fixed block */ - fixedtables(state); - Tracev((stderr, "inflate: fixed codes block%s\n", - state->last ? " (last)" : "")); - state->mode = LEN_; /* decode codes */ - if (flush == Z_TREES) { - DROPBITS(2); - goto inf_leave; - } - break; - case 2: /* dynamic block */ - Tracev((stderr, "inflate: dynamic codes block%s\n", - state->last ? " (last)" : "")); - state->mode = TABLE; - break; - case 3: - strm->msg = (char *)"invalid block type"; - state->mode = BAD; - } - DROPBITS(2); - break; - case STORED: - BYTEBITS(); /* go to byte boundary */ - NEEDBITS(32); - if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) { - strm->msg = (char *)"invalid stored block lengths"; - state->mode = BAD; - break; - } - state->length = (unsigned)hold & 0xffff; - Tracev((stderr, "inflate: stored length %u\n", - state->length)); - INITBITS(); - state->mode = COPY_; - if (flush == Z_TREES) goto inf_leave; - /* fallthrough */ - case COPY_: - state->mode = COPY; - /* fallthrough */ - case COPY: - copy = state->length; - if (copy) { - if (copy > have) copy = have; - if (copy > left) copy = left; - if (copy == 0) goto inf_leave; - zmemcpy(put, next, copy); - have -= copy; - next += copy; - left -= copy; - put += copy; - state->length -= copy; - break; - } - Tracev((stderr, "inflate: stored end\n")); - state->mode = TYPE; - break; - case TABLE: - NEEDBITS(14); - state->nlen = BITS(5) + 257; - DROPBITS(5); - state->ndist = BITS(5) + 1; - DROPBITS(5); - state->ncode = BITS(4) + 4; - DROPBITS(4); -#ifndef PKZIP_BUG_WORKAROUND - if (state->nlen > 286 || state->ndist > 30) { - strm->msg = (char *)"too many length or distance symbols"; - state->mode = BAD; - break; - } -#endif - Tracev((stderr, "inflate: table sizes ok\n")); - state->have = 0; - state->mode = LENLENS; - /* fallthrough */ - case LENLENS: - while (state->have < state->ncode) { - NEEDBITS(3); - state->lens[order[state->have++]] = (unsigned short)BITS(3); - DROPBITS(3); - } - while (state->have < 19) - state->lens[order[state->have++]] = 0; - state->next = state->codes; - state->lencode = (const code FAR *)(state->next); - state->lenbits = 7; - ret = inflate_table(CODES, state->lens, 19, &(state->next), - &(state->lenbits), state->work); - if (ret) { - strm->msg = (char *)"invalid code lengths set"; - state->mode = BAD; - break; - } - Tracev((stderr, "inflate: code lengths ok\n")); - state->have = 0; - state->mode = CODELENS; - /* fallthrough */ - case CODELENS: - while (state->have < state->nlen + state->ndist) { - for (;;) { - here = state->lencode[BITS(state->lenbits)]; - if ((unsigned)(here.bits) <= bits) break; - PULLBYTE(); - } - if (here.val < 16) { - DROPBITS(here.bits); - state->lens[state->have++] = here.val; - } - else { - if (here.val == 16) { - NEEDBITS(here.bits + 2); - DROPBITS(here.bits); - if (state->have == 0) { - strm->msg = (char *)"invalid bit length repeat"; - state->mode = BAD; - break; - } - len = state->lens[state->have - 1]; - copy = 3 + BITS(2); - DROPBITS(2); - } - else if (here.val == 17) { - NEEDBITS(here.bits + 3); - DROPBITS(here.bits); - len = 0; - copy = 3 + BITS(3); - DROPBITS(3); - } - else { - NEEDBITS(here.bits + 7); - DROPBITS(here.bits); - len = 0; - copy = 11 + BITS(7); - DROPBITS(7); - } - if (state->have + copy > state->nlen + state->ndist) { - strm->msg = (char *)"invalid bit length repeat"; - state->mode = BAD; - break; - } - while (copy--) - state->lens[state->have++] = (unsigned short)len; - } - } - - /* handle error breaks in while */ - if (state->mode == BAD) break; - - /* check for end-of-block code (better have one) */ - if (state->lens[256] == 0) { - strm->msg = (char *)"invalid code -- missing end-of-block"; - state->mode = BAD; - break; - } - - /* build code tables -- note: do not change the lenbits or distbits - values here (9 and 6) without reading the comments in inftrees.h - concerning the ENOUGH constants, which depend on those values */ - state->next = state->codes; - state->lencode = (const code FAR *)(state->next); - state->lenbits = 9; - ret = inflate_table(LENS, state->lens, state->nlen, &(state->next), - &(state->lenbits), state->work); - if (ret) { - strm->msg = (char *)"invalid literal/lengths set"; - state->mode = BAD; - break; - } - state->distcode = (const code FAR *)(state->next); - state->distbits = 6; - ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist, - &(state->next), &(state->distbits), state->work); - if (ret) { - strm->msg = (char *)"invalid distances set"; - state->mode = BAD; - break; - } - Tracev((stderr, "inflate: codes ok\n")); - state->mode = LEN_; - if (flush == Z_TREES) goto inf_leave; - /* fallthrough */ - case LEN_: - state->mode = LEN; - /* fallthrough */ - case LEN: - if (have >= 6 && left >= 258) { - RESTORE(); - inflate_fast(strm, out); - LOAD(); - if (state->mode == TYPE) - state->back = -1; - break; - } - state->back = 0; - for (;;) { - here = state->lencode[BITS(state->lenbits)]; - if ((unsigned)(here.bits) <= bits) break; - PULLBYTE(); - } - if (here.op && (here.op & 0xf0) == 0) { - last = here; - for (;;) { - here = state->lencode[last.val + - (BITS(last.bits + last.op) >> last.bits)]; - if ((unsigned)(last.bits + here.bits) <= bits) break; - PULLBYTE(); - } - DROPBITS(last.bits); - state->back += last.bits; - } - DROPBITS(here.bits); - state->back += here.bits; - state->length = (unsigned)here.val; - if ((int)(here.op) == 0) { - Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ? - "inflate: literal '%c'\n" : - "inflate: literal 0x%02x\n", here.val)); - state->mode = LIT; - break; - } - if (here.op & 32) { - Tracevv((stderr, "inflate: end of block\n")); - state->back = -1; - state->mode = TYPE; - break; - } - if (here.op & 64) { - strm->msg = (char *)"invalid literal/length code"; - state->mode = BAD; - break; - } - state->extra = (unsigned)(here.op) & 15; - state->mode = LENEXT; - /* fallthrough */ - case LENEXT: - if (state->extra) { - NEEDBITS(state->extra); - state->length += BITS(state->extra); - DROPBITS(state->extra); - state->back += state->extra; - } - Tracevv((stderr, "inflate: length %u\n", state->length)); - state->was = state->length; - state->mode = DIST; - /* fallthrough */ - case DIST: - for (;;) { - here = state->distcode[BITS(state->distbits)]; - if ((unsigned)(here.bits) <= bits) break; - PULLBYTE(); - } - if ((here.op & 0xf0) == 0) { - last = here; - for (;;) { - here = state->distcode[last.val + - (BITS(last.bits + last.op) >> last.bits)]; - if ((unsigned)(last.bits + here.bits) <= bits) break; - PULLBYTE(); - } - DROPBITS(last.bits); - state->back += last.bits; - } - DROPBITS(here.bits); - state->back += here.bits; - if (here.op & 64) { - strm->msg = (char *)"invalid distance code"; - state->mode = BAD; - break; - } - state->offset = (unsigned)here.val; - state->extra = (unsigned)(here.op) & 15; - state->mode = DISTEXT; - /* fallthrough */ - case DISTEXT: - if (state->extra) { - NEEDBITS(state->extra); - state->offset += BITS(state->extra); - DROPBITS(state->extra); - state->back += state->extra; - } -#ifdef INFLATE_STRICT - if (state->offset > state->dmax) { - strm->msg = (char *)"invalid distance too far back"; - state->mode = BAD; - break; - } -#endif - Tracevv((stderr, "inflate: distance %u\n", state->offset)); - state->mode = MATCH; - /* fallthrough */ - case MATCH: - if (left == 0) goto inf_leave; - copy = out - left; - if (state->offset > copy) { /* copy from window */ - copy = state->offset - copy; - if (copy > state->whave) { - if (state->sane) { - strm->msg = (char *)"invalid distance too far back"; - state->mode = BAD; - break; - } -#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR - Trace((stderr, "inflate.c too far\n")); - copy -= state->whave; - if (copy > state->length) copy = state->length; - if (copy > left) copy = left; - left -= copy; - state->length -= copy; - do { - *put++ = 0; - } while (--copy); - if (state->length == 0) state->mode = LEN; - break; -#endif - } - if (copy > state->wnext) { - copy -= state->wnext; - from = state->window + (state->wsize - copy); - } - else - from = state->window + (state->wnext - copy); - if (copy > state->length) copy = state->length; - } - else { /* copy from output */ - from = put - state->offset; - copy = state->length; - } - if (copy > left) copy = left; - left -= copy; - state->length -= copy; - do { - *put++ = *from++; - } while (--copy); - if (state->length == 0) state->mode = LEN; - break; - case LIT: - if (left == 0) goto inf_leave; - *put++ = (unsigned char)(state->length); - left--; - state->mode = LEN; - break; - case CHECK: - if (state->wrap) { - NEEDBITS(32); - out -= left; - strm->total_out += out; - state->total += out; - if ((state->wrap & 4) && out) - strm->adler = state->check = - UPDATE_CHECK(state->check, put - out, out); - out = left; - if ((state->wrap & 4) && ( -#ifdef GUNZIP - state->flags ? hold : -#endif - ZSWAP32(hold)) != state->check) { - strm->msg = (char *)"incorrect data check"; - state->mode = BAD; - break; - } - INITBITS(); - Tracev((stderr, "inflate: check matches trailer\n")); - } -#ifdef GUNZIP - state->mode = LENGTH; - /* fallthrough */ - case LENGTH: - if (state->wrap && state->flags) { - NEEDBITS(32); - if ((state->wrap & 4) && hold != (state->total & 0xffffffff)) { - strm->msg = (char *)"incorrect length check"; - state->mode = BAD; - break; - } - INITBITS(); - Tracev((stderr, "inflate: length matches trailer\n")); - } -#endif - state->mode = DONE; - /* fallthrough */ - case DONE: - ret = Z_STREAM_END; - goto inf_leave; - case BAD: - ret = Z_DATA_ERROR; - goto inf_leave; - case MEM: - return Z_MEM_ERROR; - case SYNC: - /* fallthrough */ - default: - return Z_STREAM_ERROR; - } - - /* - Return from inflate(), updating the total counts and the check value. - If there was no progress during the inflate() call, return a buffer - error. Call updatewindow() to create and/or update the window state. - Note: a memory error from inflate() is non-recoverable. - */ - inf_leave: - RESTORE(); - if (state->wsize || (out != strm->avail_out && state->mode < BAD && - (state->mode < CHECK || flush != Z_FINISH))) - if (updatewindow(strm, strm->next_out, out - strm->avail_out)) { - state->mode = MEM; - return Z_MEM_ERROR; - } - in -= strm->avail_in; - out -= strm->avail_out; - strm->total_in += in; - strm->total_out += out; - state->total += out; - if ((state->wrap & 4) && out) - strm->adler = state->check = - UPDATE_CHECK(state->check, strm->next_out - out, out); - strm->data_type = (int)state->bits + (state->last ? 64 : 0) + - (state->mode == TYPE ? 128 : 0) + - (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0); - if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK) - ret = Z_BUF_ERROR; - return ret; -} - -int ZEXPORT inflateEnd(strm) -z_streamp strm; -{ - struct inflate_state FAR *state; - if (inflateStateCheck(strm)) - return Z_STREAM_ERROR; - state = (struct inflate_state FAR *)strm->state; - if (state->window != Z_NULL) ZFREE(strm, state->window); - ZFREE(strm, strm->state); - strm->state = Z_NULL; - Tracev((stderr, "inflate: end\n")); - return Z_OK; -} - -int ZEXPORT inflateGetDictionary(strm, dictionary, dictLength) -z_streamp strm; -Bytef *dictionary; -uInt *dictLength; -{ - struct inflate_state FAR *state; - - /* check state */ - if (inflateStateCheck(strm)) return Z_STREAM_ERROR; - state = (struct inflate_state FAR *)strm->state; - - /* copy dictionary */ - if (state->whave && dictionary != Z_NULL) { - zmemcpy(dictionary, state->window + state->wnext, - state->whave - state->wnext); - zmemcpy(dictionary + state->whave - state->wnext, - state->window, state->wnext); - } - if (dictLength != Z_NULL) - *dictLength = state->whave; - return Z_OK; -} - -int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength) -z_streamp strm; -const Bytef *dictionary; -uInt dictLength; -{ - struct inflate_state FAR *state; - unsigned long dictid; - int ret; - - /* check state */ - if (inflateStateCheck(strm)) return Z_STREAM_ERROR; - state = (struct inflate_state FAR *)strm->state; - if (state->wrap != 0 && state->mode != DICT) - return Z_STREAM_ERROR; - - /* check for correct dictionary identifier */ - if (state->mode == DICT) { - dictid = adler32(0L, Z_NULL, 0); - dictid = adler32(dictid, dictionary, dictLength); - if (dictid != state->check) - return Z_DATA_ERROR; - } - - /* copy dictionary to window using updatewindow(), which will amend the - existing dictionary if appropriate */ - ret = updatewindow(strm, dictionary + dictLength, dictLength); - if (ret) { - state->mode = MEM; - return Z_MEM_ERROR; - } - state->havedict = 1; - Tracev((stderr, "inflate: dictionary set\n")); - return Z_OK; -} - -int ZEXPORT inflateGetHeader(strm, head) -z_streamp strm; -gz_headerp head; -{ - struct inflate_state FAR *state; - - /* check state */ - if (inflateStateCheck(strm)) return Z_STREAM_ERROR; - state = (struct inflate_state FAR *)strm->state; - if ((state->wrap & 2) == 0) return Z_STREAM_ERROR; - - /* save header structure */ - state->head = head; - head->done = 0; - return Z_OK; -} - -/* - Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found - or when out of input. When called, *have is the number of pattern bytes - found in order so far, in 0..3. On return *have is updated to the new - state. If on return *have equals four, then the pattern was found and the - return value is how many bytes were read including the last byte of the - pattern. If *have is less than four, then the pattern has not been found - yet and the return value is len. In the latter case, syncsearch() can be - called again with more data and the *have state. *have is initialized to - zero for the first call. - */ -local unsigned syncsearch(have, buf, len) -unsigned FAR *have; -const unsigned char FAR *buf; -unsigned len; -{ - unsigned got; - unsigned next; - - got = *have; - next = 0; - while (next < len && got < 4) { - if ((int)(buf[next]) == (got < 2 ? 0 : 0xff)) - got++; - else if (buf[next]) - got = 0; - else - got = 4 - got; - next++; - } - *have = got; - return next; -} - -int ZEXPORT inflateSync(strm) -z_streamp strm; -{ - unsigned len; /* number of bytes to look at or looked at */ - int flags; /* temporary to save header status */ - unsigned long in, out; /* temporary to save total_in and total_out */ - unsigned char buf[4]; /* to restore bit buffer to byte string */ - struct inflate_state FAR *state; - - /* check parameters */ - if (inflateStateCheck(strm)) return Z_STREAM_ERROR; - state = (struct inflate_state FAR *)strm->state; - if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR; - - /* if first time, start search in bit buffer */ - if (state->mode != SYNC) { - state->mode = SYNC; - state->hold <<= state->bits & 7; - state->bits -= state->bits & 7; - len = 0; - while (state->bits >= 8) { - buf[len++] = (unsigned char)(state->hold); - state->hold >>= 8; - state->bits -= 8; - } - state->have = 0; - syncsearch(&(state->have), buf, len); - } - - /* search available input */ - len = syncsearch(&(state->have), strm->next_in, strm->avail_in); - strm->avail_in -= len; - strm->next_in += len; - strm->total_in += len; - - /* return no joy or set up to restart inflate() on a new block */ - if (state->have != 4) return Z_DATA_ERROR; - if (state->flags == -1) - state->wrap = 0; /* if no header yet, treat as raw */ - else - state->wrap &= ~4; /* no point in computing a check value now */ - flags = state->flags; - in = strm->total_in; out = strm->total_out; - inflateReset(strm); - strm->total_in = in; strm->total_out = out; - state->flags = flags; - state->mode = TYPE; - return Z_OK; -} - -/* - Returns true if inflate is currently at the end of a block generated by - Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP - implementation to provide an additional safety check. PPP uses - Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored - block. When decompressing, PPP checks that at the end of input packet, - inflate is waiting for these length bytes. - */ -int ZEXPORT inflateSyncPoint(strm) -z_streamp strm; -{ - struct inflate_state FAR *state; - - if (inflateStateCheck(strm)) return Z_STREAM_ERROR; - state = (struct inflate_state FAR *)strm->state; - return state->mode == STORED && state->bits == 0; -} - -int ZEXPORT inflateCopy(dest, source) -z_streamp dest; -z_streamp source; -{ - struct inflate_state FAR *state; - struct inflate_state FAR *copy; - unsigned char FAR *window; - unsigned wsize; - - /* check input */ - if (inflateStateCheck(source) || dest == Z_NULL) - return Z_STREAM_ERROR; - state = (struct inflate_state FAR *)source->state; - - /* allocate space */ - copy = (struct inflate_state FAR *) - ZALLOC(source, 1, sizeof(struct inflate_state)); - if (copy == Z_NULL) return Z_MEM_ERROR; - window = Z_NULL; - if (state->window != Z_NULL) { - window = (unsigned char FAR *) - ZALLOC(source, 1U << state->wbits, sizeof(unsigned char)); - if (window == Z_NULL) { - ZFREE(source, copy); - return Z_MEM_ERROR; - } - } - - /* copy state */ - zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream)); - zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state)); - copy->strm = dest; - if (state->lencode >= state->codes && - state->lencode <= state->codes + ENOUGH - 1) { - copy->lencode = copy->codes + (state->lencode - state->codes); - copy->distcode = copy->codes + (state->distcode - state->codes); - } - copy->next = copy->codes + (state->next - state->codes); - if (window != Z_NULL) { - wsize = 1U << state->wbits; - zmemcpy(window, state->window, wsize); - } - copy->window = window; - dest->state = (struct internal_state FAR *)copy; - return Z_OK; -} - -int ZEXPORT inflateUndermine(strm, subvert) -z_streamp strm; -int subvert; -{ - struct inflate_state FAR *state; - - if (inflateStateCheck(strm)) return Z_STREAM_ERROR; - state = (struct inflate_state FAR *)strm->state; -#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR - state->sane = !subvert; - return Z_OK; -#else - (void)subvert; - state->sane = 1; - return Z_DATA_ERROR; -#endif -} - -int ZEXPORT inflateValidate(strm, check) -z_streamp strm; -int check; -{ - struct inflate_state FAR *state; - - if (inflateStateCheck(strm)) return Z_STREAM_ERROR; - state = (struct inflate_state FAR *)strm->state; - if (check && state->wrap) - state->wrap |= 4; - else - state->wrap &= ~4; - return Z_OK; -} - -long ZEXPORT inflateMark(strm) -z_streamp strm; -{ - struct inflate_state FAR *state; - - if (inflateStateCheck(strm)) - return -(1L << 16); - state = (struct inflate_state FAR *)strm->state; - return (long)(((unsigned long)((long)state->back)) << 16) + - (state->mode == COPY ? state->length : - (state->mode == MATCH ? state->was - state->length : 0)); -} - -unsigned long ZEXPORT inflateCodesUsed(strm) -z_streamp strm; -{ - struct inflate_state FAR *state; - if (inflateStateCheck(strm)) return (unsigned long)-1; - state = (struct inflate_state FAR *)strm->state; - return (unsigned long)(state->next - state->codes); -} +/* inflate.c -- zlib decompression
+ * Copyright (C) 1995-2022 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+ * Change history:
+ *
+ * 1.2.beta0 24 Nov 2002
+ * - First version -- complete rewrite of inflate to simplify code, avoid
+ * creation of window when not needed, minimize use of window when it is
+ * needed, make inffast.c even faster, implement gzip decoding, and to
+ * improve code readability and style over the previous zlib inflate code
+ *
+ * 1.2.beta1 25 Nov 2002
+ * - Use pointers for available input and output checking in inffast.c
+ * - Remove input and output counters in inffast.c
+ * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
+ * - Remove unnecessary second byte pull from length extra in inffast.c
+ * - Unroll direct copy to three copies per loop in inffast.c
+ *
+ * 1.2.beta2 4 Dec 2002
+ * - Change external routine names to reduce potential conflicts
+ * - Correct filename to inffixed.h for fixed tables in inflate.c
+ * - Make hbuf[] unsigned char to match parameter type in inflate.c
+ * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
+ * to avoid negation problem on Alphas (64 bit) in inflate.c
+ *
+ * 1.2.beta3 22 Dec 2002
+ * - Add comments on state->bits assertion in inffast.c
+ * - Add comments on op field in inftrees.h
+ * - Fix bug in reuse of allocated window after inflateReset()
+ * - Remove bit fields--back to byte structure for speed
+ * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
+ * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
+ * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
+ * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
+ * - Use local copies of stream next and avail values, as well as local bit
+ * buffer and bit count in inflate()--for speed when inflate_fast() not used
+ *
+ * 1.2.beta4 1 Jan 2003
+ * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
+ * - Move a comment on output buffer sizes from inffast.c to inflate.c
+ * - Add comments in inffast.c to introduce the inflate_fast() routine
+ * - Rearrange window copies in inflate_fast() for speed and simplification
+ * - Unroll last copy for window match in inflate_fast()
+ * - Use local copies of window variables in inflate_fast() for speed
+ * - Pull out common wnext == 0 case for speed in inflate_fast()
+ * - Make op and len in inflate_fast() unsigned for consistency
+ * - Add FAR to lcode and dcode declarations in inflate_fast()
+ * - Simplified bad distance check in inflate_fast()
+ * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
+ * source file infback.c to provide a call-back interface to inflate for
+ * programs like gzip and unzip -- uses window as output buffer to avoid
+ * window copying
+ *
+ * 1.2.beta5 1 Jan 2003
+ * - Improved inflateBack() interface to allow the caller to provide initial
+ * input in strm.
+ * - Fixed stored blocks bug in inflateBack()
+ *
+ * 1.2.beta6 4 Jan 2003
+ * - Added comments in inffast.c on effectiveness of POSTINC
+ * - Typecasting all around to reduce compiler warnings
+ * - Changed loops from while (1) or do {} while (1) to for (;;), again to
+ * make compilers happy
+ * - Changed type of window in inflateBackInit() to unsigned char *
+ *
+ * 1.2.beta7 27 Jan 2003
+ * - Changed many types to unsigned or unsigned short to avoid warnings
+ * - Added inflateCopy() function
+ *
+ * 1.2.0 9 Mar 2003
+ * - Changed inflateBack() interface to provide separate opaque descriptors
+ * for the in() and out() functions
+ * - Changed inflateBack() argument and in_func typedef to swap the length
+ * and buffer address return values for the input function
+ * - Check next_in and next_out for Z_NULL on entry to inflate()
+ *
+ * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+
+#ifdef MAKEFIXED
+# ifndef BUILDFIXED
+# define BUILDFIXED
+# endif
+#endif
+
+/* function prototypes */
+local int inflateStateCheck OF((z_streamp strm));
+local void fixedtables OF((struct inflate_state FAR *state));
+local int updatewindow OF((z_streamp strm, const unsigned char FAR *end,
+ unsigned copy));
+#ifdef BUILDFIXED
+ void makefixed OF((void));
+#endif
+local unsigned syncsearch OF((unsigned FAR *have, const unsigned char FAR *buf,
+ unsigned len));
+
+local int inflateStateCheck(strm)
+z_streamp strm;
+{
+ struct inflate_state FAR *state;
+ if (strm == Z_NULL ||
+ strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
+ return 1;
+ state = (struct inflate_state FAR *)strm->state;
+ if (state == Z_NULL || state->strm != strm ||
+ state->mode < HEAD || state->mode > SYNC)
+ return 1;
+ return 0;
+}
+
+int ZEXPORT inflateResetKeep(strm)
+z_streamp strm;
+{
+ struct inflate_state FAR *state;
+
+ if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ strm->total_in = strm->total_out = state->total = 0;
+ strm->msg = Z_NULL;
+ if (state->wrap) /* to support ill-conceived Java test suite */
+ strm->adler = state->wrap & 1;
+ state->mode = HEAD;
+ state->last = 0;
+ state->havedict = 0;
+ state->flags = -1;
+ state->dmax = 32768U;
+ state->head = Z_NULL;
+ state->hold = 0;
+ state->bits = 0;
+ state->lencode = state->distcode = state->next = state->codes;
+ state->sane = 1;
+ state->back = -1;
+ Tracev((stderr, "inflate: reset\n"));
+ return Z_OK;
+}
+
+int ZEXPORT inflateReset(strm)
+z_streamp strm;
+{
+ struct inflate_state FAR *state;
+
+ if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ state->wsize = 0;
+ state->whave = 0;
+ state->wnext = 0;
+ return inflateResetKeep(strm);
+}
+
+int ZEXPORT inflateReset2(strm, windowBits)
+z_streamp strm;
+int windowBits;
+{
+ int wrap;
+ struct inflate_state FAR *state;
+
+ /* get the state */
+ if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+
+ /* extract wrap request from windowBits parameter */
+ if (windowBits < 0) {
+ if (windowBits < -15)
+ return Z_STREAM_ERROR;
+ wrap = 0;
+ windowBits = -windowBits;
+ }
+ else {
+ wrap = (windowBits >> 4) + 5;
+#ifdef GUNZIP
+ if (windowBits < 48)
+ windowBits &= 15;
+#endif
+ }
+
+ /* set number of window bits, free window if different */
+ if (windowBits && (windowBits < 8 || windowBits > 15))
+ return Z_STREAM_ERROR;
+ if (state->window != Z_NULL && state->wbits != (unsigned)windowBits) {
+ ZFREE(strm, state->window);
+ state->window = Z_NULL;
+ }
+
+ /* update state and reset the rest of it */
+ state->wrap = wrap;
+ state->wbits = (unsigned)windowBits;
+ return inflateReset(strm);
+}
+
+int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
+z_streamp strm;
+int windowBits;
+const char *version;
+int stream_size;
+{
+ int ret;
+ struct inflate_state FAR *state;
+
+ if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
+ stream_size != (int)(sizeof(z_stream)))
+ return Z_VERSION_ERROR;
+ if (strm == Z_NULL) return Z_STREAM_ERROR;
+ strm->msg = Z_NULL; /* in case we return an error */
+ if (strm->zalloc == (alloc_func)0) {
+#ifdef Z_SOLO
+ return Z_STREAM_ERROR;
+#else
+ strm->zalloc = zcalloc;
+ strm->opaque = (voidpf)0;
+#endif
+ }
+ if (strm->zfree == (free_func)0)
+#ifdef Z_SOLO
+ return Z_STREAM_ERROR;
+#else
+ strm->zfree = zcfree;
+#endif
+ state = (struct inflate_state FAR *)
+ ZALLOC(strm, 1, sizeof(struct inflate_state));
+ if (state == Z_NULL) return Z_MEM_ERROR;
+ Tracev((stderr, "inflate: allocated\n"));
+ strm->state = (struct internal_state FAR *)state;
+ state->strm = strm;
+ state->window = Z_NULL;
+ state->mode = HEAD; /* to pass state test in inflateReset2() */
+ ret = inflateReset2(strm, windowBits);
+ if (ret != Z_OK) {
+ ZFREE(strm, state);
+ strm->state = Z_NULL;
+ }
+ return ret;
+}
+
+int ZEXPORT inflateInit_(strm, version, stream_size)
+z_streamp strm;
+const char *version;
+int stream_size;
+{
+ return inflateInit2_(strm, DEF_WBITS, version, stream_size);
+}
+
+int ZEXPORT inflatePrime(strm, bits, value)
+z_streamp strm;
+int bits;
+int value;
+{
+ struct inflate_state FAR *state;
+
+ if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ if (bits < 0) {
+ state->hold = 0;
+ state->bits = 0;
+ return Z_OK;
+ }
+ if (bits > 16 || state->bits + (uInt)bits > 32) return Z_STREAM_ERROR;
+ value &= (1L << bits) - 1;
+ state->hold += (unsigned)value << state->bits;
+ state->bits += (uInt)bits;
+ return Z_OK;
+}
+
+/*
+ Return state with length and distance decoding tables and index sizes set to
+ fixed code decoding. Normally this returns fixed tables from inffixed.h.
+ If BUILDFIXED is defined, then instead this routine builds the tables the
+ first time it's called, and returns those tables the first time and
+ thereafter. This reduces the size of the code by about 2K bytes, in
+ exchange for a little execution time. However, BUILDFIXED should not be
+ used for threaded applications, since the rewriting of the tables and virgin
+ may not be thread-safe.
+ */
+local void fixedtables(state)
+struct inflate_state FAR *state;
+{
+#ifdef BUILDFIXED
+ static int virgin = 1;
+ static code *lenfix, *distfix;
+ static code fixed[544];
+
+ /* build fixed huffman tables if first call (may not be thread safe) */
+ if (virgin) {
+ unsigned sym, bits;
+ static code *next;
+
+ /* literal/length table */
+ sym = 0;
+ while (sym < 144) state->lens[sym++] = 8;
+ while (sym < 256) state->lens[sym++] = 9;
+ while (sym < 280) state->lens[sym++] = 7;
+ while (sym < 288) state->lens[sym++] = 8;
+ next = fixed;
+ lenfix = next;
+ bits = 9;
+ inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
+
+ /* distance table */
+ sym = 0;
+ while (sym < 32) state->lens[sym++] = 5;
+ distfix = next;
+ bits = 5;
+ inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
+
+ /* do this just once */
+ virgin = 0;
+ }
+#else /* !BUILDFIXED */
+# include "inffixed.h"
+#endif /* BUILDFIXED */
+ state->lencode = lenfix;
+ state->lenbits = 9;
+ state->distcode = distfix;
+ state->distbits = 5;
+}
+
+#ifdef MAKEFIXED
+#include <stdio.h>
+
+/*
+ Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also
+ defines BUILDFIXED, so the tables are built on the fly. makefixed() writes
+ those tables to stdout, which would be piped to inffixed.h. A small program
+ can simply call makefixed to do this:
+
+ void makefixed(void);
+
+ int main(void)
+ {
+ makefixed();
+ return 0;
+ }
+
+ Then that can be linked with zlib built with MAKEFIXED defined and run:
+
+ a.out > inffixed.h
+ */
+void makefixed()
+{
+ unsigned low, size;
+ struct inflate_state state;
+
+ fixedtables(&state);
+ puts(" /* inffixed.h -- table for decoding fixed codes");
+ puts(" * Generated automatically by makefixed().");
+ puts(" */");
+ puts("");
+ puts(" /* WARNING: this file should *not* be used by applications.");
+ puts(" It is part of the implementation of this library and is");
+ puts(" subject to change. Applications should only use zlib.h.");
+ puts(" */");
+ puts("");
+ size = 1U << 9;
+ printf(" static const code lenfix[%u] = {", size);
+ low = 0;
+ for (;;) {
+ if ((low % 7) == 0) printf("\n ");
+ printf("{%u,%u,%d}", (low & 127) == 99 ? 64 : state.lencode[low].op,
+ state.lencode[low].bits, state.lencode[low].val);
+ if (++low == size) break;
+ putchar(',');
+ }
+ puts("\n };");
+ size = 1U << 5;
+ printf("\n static const code distfix[%u] = {", size);
+ low = 0;
+ for (;;) {
+ if ((low % 6) == 0) printf("\n ");
+ printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
+ state.distcode[low].val);
+ if (++low == size) break;
+ putchar(',');
+ }
+ puts("\n };");
+}
+#endif /* MAKEFIXED */
+
+/*
+ Update the window with the last wsize (normally 32K) bytes written before
+ returning. If window does not exist yet, create it. This is only called
+ when a window is already in use, or when output has been written during this
+ inflate call, but the end of the deflate stream has not been reached yet.
+ It is also called to create a window for dictionary data when a dictionary
+ is loaded.
+
+ Providing output buffers larger than 32K to inflate() should provide a speed
+ advantage, since only the last 32K of output is copied to the sliding window
+ upon return from inflate(), and since all distances after the first 32K of
+ output will fall in the output data, making match copies simpler and faster.
+ The advantage may be dependent on the size of the processor's data caches.
+ */
+local int updatewindow(strm, end, copy)
+z_streamp strm;
+const Bytef *end;
+unsigned copy;
+{
+ struct inflate_state FAR *state;
+ unsigned dist;
+
+ state = (struct inflate_state FAR *)strm->state;
+
+ /* if it hasn't been done already, allocate space for the window */
+ if (state->window == Z_NULL) {
+ state->window = (unsigned char FAR *)
+ ZALLOC(strm, 1U << state->wbits,
+ sizeof(unsigned char));
+ if (state->window == Z_NULL) return 1;
+ }
+
+ /* if window not in use yet, initialize */
+ if (state->wsize == 0) {
+ state->wsize = 1U << state->wbits;
+ state->wnext = 0;
+ state->whave = 0;
+ }
+
+ /* copy state->wsize or less output bytes into the circular window */
+ if (copy >= state->wsize) {
+ zmemcpy(state->window, end - state->wsize, state->wsize);
+ state->wnext = 0;
+ state->whave = state->wsize;
+ }
+ else {
+ dist = state->wsize - state->wnext;
+ if (dist > copy) dist = copy;
+ zmemcpy(state->window + state->wnext, end - copy, dist);
+ copy -= dist;
+ if (copy) {
+ zmemcpy(state->window, end - copy, copy);
+ state->wnext = copy;
+ state->whave = state->wsize;
+ }
+ else {
+ state->wnext += dist;
+ if (state->wnext == state->wsize) state->wnext = 0;
+ if (state->whave < state->wsize) state->whave += dist;
+ }
+ }
+ return 0;
+}
+
+/* Macros for inflate(): */
+
+/* check function to use adler32() for zlib or crc32() for gzip */
+#ifdef GUNZIP
+# define UPDATE_CHECK(check, buf, len) \
+ (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
+#else
+# define UPDATE_CHECK(check, buf, len) adler32(check, buf, len)
+#endif
+
+/* check macros for header crc */
+#ifdef GUNZIP
+# define CRC2(check, word) \
+ do { \
+ hbuf[0] = (unsigned char)(word); \
+ hbuf[1] = (unsigned char)((word) >> 8); \
+ check = crc32(check, hbuf, 2); \
+ } while (0)
+
+# define CRC4(check, word) \
+ do { \
+ hbuf[0] = (unsigned char)(word); \
+ hbuf[1] = (unsigned char)((word) >> 8); \
+ hbuf[2] = (unsigned char)((word) >> 16); \
+ hbuf[3] = (unsigned char)((word) >> 24); \
+ check = crc32(check, hbuf, 4); \
+ } while (0)
+#endif
+
+/* Load registers with state in inflate() for speed */
+#define LOAD() \
+ do { \
+ put = strm->next_out; \
+ left = strm->avail_out; \
+ next = strm->next_in; \
+ have = strm->avail_in; \
+ hold = state->hold; \
+ bits = state->bits; \
+ } while (0)
+
+/* Restore state from registers in inflate() */
+#define RESTORE() \
+ do { \
+ strm->next_out = put; \
+ strm->avail_out = left; \
+ strm->next_in = next; \
+ strm->avail_in = have; \
+ state->hold = hold; \
+ state->bits = bits; \
+ } while (0)
+
+/* Clear the input bit accumulator */
+#define INITBITS() \
+ do { \
+ hold = 0; \
+ bits = 0; \
+ } while (0)
+
+/* Get a byte of input into the bit accumulator, or return from inflate()
+ if there is no input available. */
+#define PULLBYTE() \
+ do { \
+ if (have == 0) goto inf_leave; \
+ have--; \
+ hold += (unsigned long)(*next++) << bits; \
+ bits += 8; \
+ } while (0)
+
+/* Assure that there are at least n bits in the bit accumulator. If there is
+ not enough available input to do that, then return from inflate(). */
+#define NEEDBITS(n) \
+ do { \
+ while (bits < (unsigned)(n)) \
+ PULLBYTE(); \
+ } while (0)
+
+/* Return the low n bits of the bit accumulator (n < 16) */
+#define BITS(n) \
+ ((unsigned)hold & ((1U << (n)) - 1))
+
+/* Remove n bits from the bit accumulator */
+#define DROPBITS(n) \
+ do { \
+ hold >>= (n); \
+ bits -= (unsigned)(n); \
+ } while (0)
+
+/* Remove zero to seven bits as needed to go to a byte boundary */
+#define BYTEBITS() \
+ do { \
+ hold >>= bits & 7; \
+ bits -= bits & 7; \
+ } while (0)
+
+/*
+ inflate() uses a state machine to process as much input data and generate as
+ much output data as possible before returning. The state machine is
+ structured roughly as follows:
+
+ for (;;) switch (state) {
+ ...
+ case STATEn:
+ if (not enough input data or output space to make progress)
+ return;
+ ... make progress ...
+ state = STATEm;
+ break;
+ ...
+ }
+
+ so when inflate() is called again, the same case is attempted again, and
+ if the appropriate resources are provided, the machine proceeds to the
+ next state. The NEEDBITS() macro is usually the way the state evaluates
+ whether it can proceed or should return. NEEDBITS() does the return if
+ the requested bits are not available. The typical use of the BITS macros
+ is:
+
+ NEEDBITS(n);
+ ... do something with BITS(n) ...
+ DROPBITS(n);
+
+ where NEEDBITS(n) either returns from inflate() if there isn't enough
+ input left to load n bits into the accumulator, or it continues. BITS(n)
+ gives the low n bits in the accumulator. When done, DROPBITS(n) drops
+ the low n bits off the accumulator. INITBITS() clears the accumulator
+ and sets the number of available bits to zero. BYTEBITS() discards just
+ enough bits to put the accumulator on a byte boundary. After BYTEBITS()
+ and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
+
+ NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
+ if there is no input available. The decoding of variable length codes uses
+ PULLBYTE() directly in order to pull just enough bytes to decode the next
+ code, and no more.
+
+ Some states loop until they get enough input, making sure that enough
+ state information is maintained to continue the loop where it left off
+ if NEEDBITS() returns in the loop. For example, want, need, and keep
+ would all have to actually be part of the saved state in case NEEDBITS()
+ returns:
+
+ case STATEw:
+ while (want < need) {
+ NEEDBITS(n);
+ keep[want++] = BITS(n);
+ DROPBITS(n);
+ }
+ state = STATEx;
+ case STATEx:
+
+ As shown above, if the next state is also the next case, then the break
+ is omitted.
+
+ A state may also return if there is not enough output space available to
+ complete that state. Those states are copying stored data, writing a
+ literal byte, and copying a matching string.
+
+ When returning, a "goto inf_leave" is used to update the total counters,
+ update the check value, and determine whether any progress has been made
+ during that inflate() call in order to return the proper return code.
+ Progress is defined as a change in either strm->avail_in or strm->avail_out.
+ When there is a window, goto inf_leave will update the window with the last
+ output written. If a goto inf_leave occurs in the middle of decompression
+ and there is no window currently, goto inf_leave will create one and copy
+ output to the window for the next call of inflate().
+
+ In this implementation, the flush parameter of inflate() only affects the
+ return code (per zlib.h). inflate() always writes as much as possible to
+ strm->next_out, given the space available and the provided input--the effect
+ documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
+ the allocation of and copying into a sliding window until necessary, which
+ provides the effect documented in zlib.h for Z_FINISH when the entire input
+ stream available. So the only thing the flush parameter actually does is:
+ when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
+ will return Z_BUF_ERROR if it has not reached the end of the stream.
+ */
+
+int ZEXPORT inflate(strm, flush)
+z_streamp strm;
+int flush;
+{
+ struct inflate_state FAR *state;
+ z_const unsigned char FAR *next; /* next input */
+ unsigned char FAR *put; /* next output */
+ unsigned have, left; /* available input and output */
+ unsigned long hold; /* bit buffer */
+ unsigned bits; /* bits in bit buffer */
+ unsigned in, out; /* save starting available input and output */
+ unsigned copy; /* number of stored or match bytes to copy */
+ unsigned char FAR *from; /* where to copy match bytes from */
+ code here; /* current decoding table entry */
+ code last; /* parent table entry */
+ unsigned len; /* length to copy for repeats, bits to drop */
+ int ret; /* return code */
+#ifdef GUNZIP
+ unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
+#endif
+ static const unsigned short order[19] = /* permutation of code lengths */
+ {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+ if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
+ (strm->next_in == Z_NULL && strm->avail_in != 0))
+ return Z_STREAM_ERROR;
+
+ state = (struct inflate_state FAR *)strm->state;
+ if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
+ LOAD();
+ in = have;
+ out = left;
+ ret = Z_OK;
+ for (;;)
+ switch (state->mode) {
+ case HEAD:
+ if (state->wrap == 0) {
+ state->mode = TYPEDO;
+ break;
+ }
+ NEEDBITS(16);
+#ifdef GUNZIP
+ if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
+ if (state->wbits == 0)
+ state->wbits = 15;
+ state->check = crc32(0L, Z_NULL, 0);
+ CRC2(state->check, hold);
+ INITBITS();
+ state->mode = FLAGS;
+ break;
+ }
+ if (state->head != Z_NULL)
+ state->head->done = -1;
+ if (!(state->wrap & 1) || /* check if zlib header allowed */
+#else
+ if (
+#endif
+ ((BITS(8) << 8) + (hold >> 8)) % 31) {
+ strm->msg = (char *)"incorrect header check";
+ state->mode = BAD;
+ break;
+ }
+ if (BITS(4) != Z_DEFLATED) {
+ strm->msg = (char *)"unknown compression method";
+ state->mode = BAD;
+ break;
+ }
+ DROPBITS(4);
+ len = BITS(4) + 8;
+ if (state->wbits == 0)
+ state->wbits = len;
+ if (len > 15 || len > state->wbits) {
+ strm->msg = (char *)"invalid window size";
+ state->mode = BAD;
+ break;
+ }
+ state->dmax = 1U << len;
+ state->flags = 0; /* indicate zlib header */
+ Tracev((stderr, "inflate: zlib header ok\n"));
+ strm->adler = state->check = adler32(0L, Z_NULL, 0);
+ state->mode = hold & 0x200 ? DICTID : TYPE;
+ INITBITS();
+ break;
+#ifdef GUNZIP
+ case FLAGS:
+ NEEDBITS(16);
+ state->flags = (int)(hold);
+ if ((state->flags & 0xff) != Z_DEFLATED) {
+ strm->msg = (char *)"unknown compression method";
+ state->mode = BAD;
+ break;
+ }
+ if (state->flags & 0xe000) {
+ strm->msg = (char *)"unknown header flags set";
+ state->mode = BAD;
+ break;
+ }
+ if (state->head != Z_NULL)
+ state->head->text = (int)((hold >> 8) & 1);
+ if ((state->flags & 0x0200) && (state->wrap & 4))
+ CRC2(state->check, hold);
+ INITBITS();
+ state->mode = TIME;
+ /* fallthrough */
+ case TIME:
+ NEEDBITS(32);
+ if (state->head != Z_NULL)
+ state->head->time = hold;
+ if ((state->flags & 0x0200) && (state->wrap & 4))
+ CRC4(state->check, hold);
+ INITBITS();
+ state->mode = OS;
+ /* fallthrough */
+ case OS:
+ NEEDBITS(16);
+ if (state->head != Z_NULL) {
+ state->head->xflags = (int)(hold & 0xff);
+ state->head->os = (int)(hold >> 8);
+ }
+ if ((state->flags & 0x0200) && (state->wrap & 4))
+ CRC2(state->check, hold);
+ INITBITS();
+ state->mode = EXLEN;
+ /* fallthrough */
+ case EXLEN:
+ if (state->flags & 0x0400) {
+ NEEDBITS(16);
+ state->length = (unsigned)(hold);
+ if (state->head != Z_NULL)
+ state->head->extra_len = (unsigned)hold;
+ if ((state->flags & 0x0200) && (state->wrap & 4))
+ CRC2(state->check, hold);
+ INITBITS();
+ }
+ else if (state->head != Z_NULL)
+ state->head->extra = Z_NULL;
+ state->mode = EXTRA;
+ /* fallthrough */
+ case EXTRA:
+ if (state->flags & 0x0400) {
+ copy = state->length;
+ if (copy > have) copy = have;
+ if (copy) {
+ if (state->head != Z_NULL &&
+ state->head->extra != Z_NULL &&
+ (len = state->head->extra_len - state->length) <
+ state->head->extra_max) {
+ zmemcpy(state->head->extra + len, next,
+ len + copy > state->head->extra_max ?
+ state->head->extra_max - len : copy);
+ }
+ if ((state->flags & 0x0200) && (state->wrap & 4))
+ state->check = crc32(state->check, next, copy);
+ have -= copy;
+ next += copy;
+ state->length -= copy;
+ }
+ if (state->length) goto inf_leave;
+ }
+ state->length = 0;
+ state->mode = NAME;
+ /* fallthrough */
+ case NAME:
+ if (state->flags & 0x0800) {
+ if (have == 0) goto inf_leave;
+ copy = 0;
+ do {
+ len = (unsigned)(next[copy++]);
+ if (state->head != Z_NULL &&
+ state->head->name != Z_NULL &&
+ state->length < state->head->name_max)
+ state->head->name[state->length++] = (Bytef)len;
+ } while (len && copy < have);
+ if ((state->flags & 0x0200) && (state->wrap & 4))
+ state->check = crc32(state->check, next, copy);
+ have -= copy;
+ next += copy;
+ if (len) goto inf_leave;
+ }
+ else if (state->head != Z_NULL)
+ state->head->name = Z_NULL;
+ state->length = 0;
+ state->mode = COMMENT;
+ /* fallthrough */
+ case COMMENT:
+ if (state->flags & 0x1000) {
+ if (have == 0) goto inf_leave;
+ copy = 0;
+ do {
+ len = (unsigned)(next[copy++]);
+ if (state->head != Z_NULL &&
+ state->head->comment != Z_NULL &&
+ state->length < state->head->comm_max)
+ state->head->comment[state->length++] = (Bytef)len;
+ } while (len && copy < have);
+ if ((state->flags & 0x0200) && (state->wrap & 4))
+ state->check = crc32(state->check, next, copy);
+ have -= copy;
+ next += copy;
+ if (len) goto inf_leave;
+ }
+ else if (state->head != Z_NULL)
+ state->head->comment = Z_NULL;
+ state->mode = HCRC;
+ /* fallthrough */
+ case HCRC:
+ if (state->flags & 0x0200) {
+ NEEDBITS(16);
+ if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
+ strm->msg = (char *)"header crc mismatch";
+ state->mode = BAD;
+ break;
+ }
+ INITBITS();
+ }
+ if (state->head != Z_NULL) {
+ state->head->hcrc = (int)((state->flags >> 9) & 1);
+ state->head->done = 1;
+ }
+ strm->adler = state->check = crc32(0L, Z_NULL, 0);
+ state->mode = TYPE;
+ break;
+#endif
+ case DICTID:
+ NEEDBITS(32);
+ strm->adler = state->check = ZSWAP32(hold);
+ INITBITS();
+ state->mode = DICT;
+ /* fallthrough */
+ case DICT:
+ if (state->havedict == 0) {
+ RESTORE();
+ return Z_NEED_DICT;
+ }
+ strm->adler = state->check = adler32(0L, Z_NULL, 0);
+ state->mode = TYPE;
+ /* fallthrough */
+ case TYPE:
+ if (flush == Z_BLOCK || flush == Z_TREES) goto inf_leave;
+ /* fallthrough */
+ case TYPEDO:
+ if (state->last) {
+ BYTEBITS();
+ state->mode = CHECK;
+ break;
+ }
+ NEEDBITS(3);
+ state->last = BITS(1);
+ DROPBITS(1);
+ switch (BITS(2)) {
+ case 0: /* stored block */
+ Tracev((stderr, "inflate: stored block%s\n",
+ state->last ? " (last)" : ""));
+ state->mode = STORED;
+ break;
+ case 1: /* fixed block */
+ fixedtables(state);
+ Tracev((stderr, "inflate: fixed codes block%s\n",
+ state->last ? " (last)" : ""));
+ state->mode = LEN_; /* decode codes */
+ if (flush == Z_TREES) {
+ DROPBITS(2);
+ goto inf_leave;
+ }
+ break;
+ case 2: /* dynamic block */
+ Tracev((stderr, "inflate: dynamic codes block%s\n",
+ state->last ? " (last)" : ""));
+ state->mode = TABLE;
+ break;
+ case 3:
+ strm->msg = (char *)"invalid block type";
+ state->mode = BAD;
+ }
+ DROPBITS(2);
+ break;
+ case STORED:
+ BYTEBITS(); /* go to byte boundary */
+ NEEDBITS(32);
+ if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
+ strm->msg = (char *)"invalid stored block lengths";
+ state->mode = BAD;
+ break;
+ }
+ state->length = (unsigned)hold & 0xffff;
+ Tracev((stderr, "inflate: stored length %u\n",
+ state->length));
+ INITBITS();
+ state->mode = COPY_;
+ if (flush == Z_TREES) goto inf_leave;
+ /* fallthrough */
+ case COPY_:
+ state->mode = COPY;
+ /* fallthrough */
+ case COPY:
+ copy = state->length;
+ if (copy) {
+ if (copy > have) copy = have;
+ if (copy > left) copy = left;
+ if (copy == 0) goto inf_leave;
+ zmemcpy(put, next, copy);
+ have -= copy;
+ next += copy;
+ left -= copy;
+ put += copy;
+ state->length -= copy;
+ break;
+ }
+ Tracev((stderr, "inflate: stored end\n"));
+ state->mode = TYPE;
+ break;
+ case TABLE:
+ NEEDBITS(14);
+ state->nlen = BITS(5) + 257;
+ DROPBITS(5);
+ state->ndist = BITS(5) + 1;
+ DROPBITS(5);
+ state->ncode = BITS(4) + 4;
+ DROPBITS(4);
+#ifndef PKZIP_BUG_WORKAROUND
+ if (state->nlen > 286 || state->ndist > 30) {
+ strm->msg = (char *)"too many length or distance symbols";
+ state->mode = BAD;
+ break;
+ }
+#endif
+ Tracev((stderr, "inflate: table sizes ok\n"));
+ state->have = 0;
+ state->mode = LENLENS;
+ /* fallthrough */
+ case LENLENS:
+ while (state->have < state->ncode) {
+ NEEDBITS(3);
+ state->lens[order[state->have++]] = (unsigned short)BITS(3);
+ DROPBITS(3);
+ }
+ while (state->have < 19)
+ state->lens[order[state->have++]] = 0;
+ state->next = state->codes;
+ state->lencode = (const code FAR *)(state->next);
+ state->lenbits = 7;
+ ret = inflate_table(CODES, state->lens, 19, &(state->next),
+ &(state->lenbits), state->work);
+ if (ret) {
+ strm->msg = (char *)"invalid code lengths set";
+ state->mode = BAD;
+ break;
+ }
+ Tracev((stderr, "inflate: code lengths ok\n"));
+ state->have = 0;
+ state->mode = CODELENS;
+ /* fallthrough */
+ case CODELENS:
+ while (state->have < state->nlen + state->ndist) {
+ for (;;) {
+ here = state->lencode[BITS(state->lenbits)];
+ if ((unsigned)(here.bits) <= bits) break;
+ PULLBYTE();
+ }
+ if (here.val < 16) {
+ DROPBITS(here.bits);
+ state->lens[state->have++] = here.val;
+ }
+ else {
+ if (here.val == 16) {
+ NEEDBITS(here.bits + 2);
+ DROPBITS(here.bits);
+ if (state->have == 0) {
+ strm->msg = (char *)"invalid bit length repeat";
+ state->mode = BAD;
+ break;
+ }
+ len = state->lens[state->have - 1];
+ copy = 3 + BITS(2);
+ DROPBITS(2);
+ }
+ else if (here.val == 17) {
+ NEEDBITS(here.bits + 3);
+ DROPBITS(here.bits);
+ len = 0;
+ copy = 3 + BITS(3);
+ DROPBITS(3);
+ }
+ else {
+ NEEDBITS(here.bits + 7);
+ DROPBITS(here.bits);
+ len = 0;
+ copy = 11 + BITS(7);
+ DROPBITS(7);
+ }
+ if (state->have + copy > state->nlen + state->ndist) {
+ strm->msg = (char *)"invalid bit length repeat";
+ state->mode = BAD;
+ break;
+ }
+ while (copy--)
+ state->lens[state->have++] = (unsigned short)len;
+ }
+ }
+
+ /* handle error breaks in while */
+ if (state->mode == BAD) break;
+
+ /* check for end-of-block code (better have one) */
+ if (state->lens[256] == 0) {
+ strm->msg = (char *)"invalid code -- missing end-of-block";
+ state->mode = BAD;
+ break;
+ }
+
+ /* build code tables -- note: do not change the lenbits or distbits
+ values here (9 and 6) without reading the comments in inftrees.h
+ concerning the ENOUGH constants, which depend on those values */
+ state->next = state->codes;
+ state->lencode = (const code FAR *)(state->next);
+ state->lenbits = 9;
+ ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
+ &(state->lenbits), state->work);
+ if (ret) {
+ strm->msg = (char *)"invalid literal/lengths set";
+ state->mode = BAD;
+ break;
+ }
+ state->distcode = (const code FAR *)(state->next);
+ state->distbits = 6;
+ ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
+ &(state->next), &(state->distbits), state->work);
+ if (ret) {
+ strm->msg = (char *)"invalid distances set";
+ state->mode = BAD;
+ break;
+ }
+ Tracev((stderr, "inflate: codes ok\n"));
+ state->mode = LEN_;
+ if (flush == Z_TREES) goto inf_leave;
+ /* fallthrough */
+ case LEN_:
+ state->mode = LEN;
+ /* fallthrough */
+ case LEN:
+ if (have >= 6 && left >= 258) {
+ RESTORE();
+ inflate_fast(strm, out);
+ LOAD();
+ if (state->mode == TYPE)
+ state->back = -1;
+ break;
+ }
+ state->back = 0;
+ for (;;) {
+ here = state->lencode[BITS(state->lenbits)];
+ if ((unsigned)(here.bits) <= bits) break;
+ PULLBYTE();
+ }
+ if (here.op && (here.op & 0xf0) == 0) {
+ last = here;
+ for (;;) {
+ here = state->lencode[last.val +
+ (BITS(last.bits + last.op) >> last.bits)];
+ if ((unsigned)(last.bits + here.bits) <= bits) break;
+ PULLBYTE();
+ }
+ DROPBITS(last.bits);
+ state->back += last.bits;
+ }
+ DROPBITS(here.bits);
+ state->back += here.bits;
+ state->length = (unsigned)here.val;
+ if ((int)(here.op) == 0) {
+ Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
+ "inflate: literal '%c'\n" :
+ "inflate: literal 0x%02x\n", here.val));
+ state->mode = LIT;
+ break;
+ }
+ if (here.op & 32) {
+ Tracevv((stderr, "inflate: end of block\n"));
+ state->back = -1;
+ state->mode = TYPE;
+ break;
+ }
+ if (here.op & 64) {
+ strm->msg = (char *)"invalid literal/length code";
+ state->mode = BAD;
+ break;
+ }
+ state->extra = (unsigned)(here.op) & 15;
+ state->mode = LENEXT;
+ /* fallthrough */
+ case LENEXT:
+ if (state->extra) {
+ NEEDBITS(state->extra);
+ state->length += BITS(state->extra);
+ DROPBITS(state->extra);
+ state->back += state->extra;
+ }
+ Tracevv((stderr, "inflate: length %u\n", state->length));
+ state->was = state->length;
+ state->mode = DIST;
+ /* fallthrough */
+ case DIST:
+ for (;;) {
+ here = state->distcode[BITS(state->distbits)];
+ if ((unsigned)(here.bits) <= bits) break;
+ PULLBYTE();
+ }
+ if ((here.op & 0xf0) == 0) {
+ last = here;
+ for (;;) {
+ here = state->distcode[last.val +
+ (BITS(last.bits + last.op) >> last.bits)];
+ if ((unsigned)(last.bits + here.bits) <= bits) break;
+ PULLBYTE();
+ }
+ DROPBITS(last.bits);
+ state->back += last.bits;
+ }
+ DROPBITS(here.bits);
+ state->back += here.bits;
+ if (here.op & 64) {
+ strm->msg = (char *)"invalid distance code";
+ state->mode = BAD;
+ break;
+ }
+ state->offset = (unsigned)here.val;
+ state->extra = (unsigned)(here.op) & 15;
+ state->mode = DISTEXT;
+ /* fallthrough */
+ case DISTEXT:
+ if (state->extra) {
+ NEEDBITS(state->extra);
+ state->offset += BITS(state->extra);
+ DROPBITS(state->extra);
+ state->back += state->extra;
+ }
+#ifdef INFLATE_STRICT
+ if (state->offset > state->dmax) {
+ strm->msg = (char *)"invalid distance too far back";
+ state->mode = BAD;
+ break;
+ }
+#endif
+ Tracevv((stderr, "inflate: distance %u\n", state->offset));
+ state->mode = MATCH;
+ /* fallthrough */
+ case MATCH:
+ if (left == 0) goto inf_leave;
+ copy = out - left;
+ if (state->offset > copy) { /* copy from window */
+ copy = state->offset - copy;
+ if (copy > state->whave) {
+ if (state->sane) {
+ strm->msg = (char *)"invalid distance too far back";
+ state->mode = BAD;
+ break;
+ }
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+ Trace((stderr, "inflate.c too far\n"));
+ copy -= state->whave;
+ if (copy > state->length) copy = state->length;
+ if (copy > left) copy = left;
+ left -= copy;
+ state->length -= copy;
+ do {
+ *put++ = 0;
+ } while (--copy);
+ if (state->length == 0) state->mode = LEN;
+ break;
+#endif
+ }
+ if (copy > state->wnext) {
+ copy -= state->wnext;
+ from = state->window + (state->wsize - copy);
+ }
+ else
+ from = state->window + (state->wnext - copy);
+ if (copy > state->length) copy = state->length;
+ }
+ else { /* copy from output */
+ from = put - state->offset;
+ copy = state->length;
+ }
+ if (copy > left) copy = left;
+ left -= copy;
+ state->length -= copy;
+ do {
+ *put++ = *from++;
+ } while (--copy);
+ if (state->length == 0) state->mode = LEN;
+ break;
+ case LIT:
+ if (left == 0) goto inf_leave;
+ *put++ = (unsigned char)(state->length);
+ left--;
+ state->mode = LEN;
+ break;
+ case CHECK:
+ if (state->wrap) {
+ NEEDBITS(32);
+ out -= left;
+ strm->total_out += out;
+ state->total += out;
+ if ((state->wrap & 4) && out)
+ strm->adler = state->check =
+ UPDATE_CHECK(state->check, put - out, out);
+ out = left;
+ if ((state->wrap & 4) && (
+#ifdef GUNZIP
+ state->flags ? hold :
+#endif
+ ZSWAP32(hold)) != state->check) {
+ strm->msg = (char *)"incorrect data check";
+ state->mode = BAD;
+ break;
+ }
+ INITBITS();
+ Tracev((stderr, "inflate: check matches trailer\n"));
+ }
+#ifdef GUNZIP
+ state->mode = LENGTH;
+ /* fallthrough */
+ case LENGTH:
+ if (state->wrap && state->flags) {
+ NEEDBITS(32);
+ if ((state->wrap & 4) && hold != (state->total & 0xffffffff)) {
+ strm->msg = (char *)"incorrect length check";
+ state->mode = BAD;
+ break;
+ }
+ INITBITS();
+ Tracev((stderr, "inflate: length matches trailer\n"));
+ }
+#endif
+ state->mode = DONE;
+ /* fallthrough */
+ case DONE:
+ ret = Z_STREAM_END;
+ goto inf_leave;
+ case BAD:
+ ret = Z_DATA_ERROR;
+ goto inf_leave;
+ case MEM:
+ return Z_MEM_ERROR;
+ case SYNC:
+ /* fallthrough */
+ default:
+ return Z_STREAM_ERROR;
+ }
+
+ /*
+ Return from inflate(), updating the total counts and the check value.
+ If there was no progress during the inflate() call, return a buffer
+ error. Call updatewindow() to create and/or update the window state.
+ Note: a memory error from inflate() is non-recoverable.
+ */
+ inf_leave:
+ RESTORE();
+ if (state->wsize || (out != strm->avail_out && state->mode < BAD &&
+ (state->mode < CHECK || flush != Z_FINISH)))
+ if (updatewindow(strm, strm->next_out, out - strm->avail_out)) {
+ state->mode = MEM;
+ return Z_MEM_ERROR;
+ }
+ in -= strm->avail_in;
+ out -= strm->avail_out;
+ strm->total_in += in;
+ strm->total_out += out;
+ state->total += out;
+ if ((state->wrap & 4) && out)
+ strm->adler = state->check =
+ UPDATE_CHECK(state->check, strm->next_out - out, out);
+ strm->data_type = (int)state->bits + (state->last ? 64 : 0) +
+ (state->mode == TYPE ? 128 : 0) +
+ (state->mode == LEN_ || state->mode == COPY_ ? 256 : 0);
+ if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
+ ret = Z_BUF_ERROR;
+ return ret;
+}
+
+int ZEXPORT inflateEnd(strm)
+z_streamp strm;
+{
+ struct inflate_state FAR *state;
+ if (inflateStateCheck(strm))
+ return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ if (state->window != Z_NULL) ZFREE(strm, state->window);
+ ZFREE(strm, strm->state);
+ strm->state = Z_NULL;
+ Tracev((stderr, "inflate: end\n"));
+ return Z_OK;
+}
+
+int ZEXPORT inflateGetDictionary(strm, dictionary, dictLength)
+z_streamp strm;
+Bytef *dictionary;
+uInt *dictLength;
+{
+ struct inflate_state FAR *state;
+
+ /* check state */
+ if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+
+ /* copy dictionary */
+ if (state->whave && dictionary != Z_NULL) {
+ zmemcpy(dictionary, state->window + state->wnext,
+ state->whave - state->wnext);
+ zmemcpy(dictionary + state->whave - state->wnext,
+ state->window, state->wnext);
+ }
+ if (dictLength != Z_NULL)
+ *dictLength = state->whave;
+ return Z_OK;
+}
+
+int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
+z_streamp strm;
+const Bytef *dictionary;
+uInt dictLength;
+{
+ struct inflate_state FAR *state;
+ unsigned long dictid;
+ int ret;
+
+ /* check state */
+ if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ if (state->wrap != 0 && state->mode != DICT)
+ return Z_STREAM_ERROR;
+
+ /* check for correct dictionary identifier */
+ if (state->mode == DICT) {
+ dictid = adler32(0L, Z_NULL, 0);
+ dictid = adler32(dictid, dictionary, dictLength);
+ if (dictid != state->check)
+ return Z_DATA_ERROR;
+ }
+
+ /* copy dictionary to window using updatewindow(), which will amend the
+ existing dictionary if appropriate */
+ ret = updatewindow(strm, dictionary + dictLength, dictLength);
+ if (ret) {
+ state->mode = MEM;
+ return Z_MEM_ERROR;
+ }
+ state->havedict = 1;
+ Tracev((stderr, "inflate: dictionary set\n"));
+ return Z_OK;
+}
+
+int ZEXPORT inflateGetHeader(strm, head)
+z_streamp strm;
+gz_headerp head;
+{
+ struct inflate_state FAR *state;
+
+ /* check state */
+ if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
+
+ /* save header structure */
+ state->head = head;
+ head->done = 0;
+ return Z_OK;
+}
+
+/*
+ Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found
+ or when out of input. When called, *have is the number of pattern bytes
+ found in order so far, in 0..3. On return *have is updated to the new
+ state. If on return *have equals four, then the pattern was found and the
+ return value is how many bytes were read including the last byte of the
+ pattern. If *have is less than four, then the pattern has not been found
+ yet and the return value is len. In the latter case, syncsearch() can be
+ called again with more data and the *have state. *have is initialized to
+ zero for the first call.
+ */
+local unsigned syncsearch(have, buf, len)
+unsigned FAR *have;
+const unsigned char FAR *buf;
+unsigned len;
+{
+ unsigned got;
+ unsigned next;
+
+ got = *have;
+ next = 0;
+ while (next < len && got < 4) {
+ if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
+ got++;
+ else if (buf[next])
+ got = 0;
+ else
+ got = 4 - got;
+ next++;
+ }
+ *have = got;
+ return next;
+}
+
+int ZEXPORT inflateSync(strm)
+z_streamp strm;
+{
+ unsigned len; /* number of bytes to look at or looked at */
+ int flags; /* temporary to save header status */
+ unsigned long in, out; /* temporary to save total_in and total_out */
+ unsigned char buf[4]; /* to restore bit buffer to byte string */
+ struct inflate_state FAR *state;
+
+ /* check parameters */
+ if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
+
+ /* if first time, start search in bit buffer */
+ if (state->mode != SYNC) {
+ state->mode = SYNC;
+ state->hold <<= state->bits & 7;
+ state->bits -= state->bits & 7;
+ len = 0;
+ while (state->bits >= 8) {
+ buf[len++] = (unsigned char)(state->hold);
+ state->hold >>= 8;
+ state->bits -= 8;
+ }
+ state->have = 0;
+ syncsearch(&(state->have), buf, len);
+ }
+
+ /* search available input */
+ len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
+ strm->avail_in -= len;
+ strm->next_in += len;
+ strm->total_in += len;
+
+ /* return no joy or set up to restart inflate() on a new block */
+ if (state->have != 4) return Z_DATA_ERROR;
+ if (state->flags == -1)
+ state->wrap = 0; /* if no header yet, treat as raw */
+ else
+ state->wrap &= ~4; /* no point in computing a check value now */
+ flags = state->flags;
+ in = strm->total_in; out = strm->total_out;
+ inflateReset(strm);
+ strm->total_in = in; strm->total_out = out;
+ state->flags = flags;
+ state->mode = TYPE;
+ return Z_OK;
+}
+
+/*
+ Returns true if inflate is currently at the end of a block generated by
+ Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
+ implementation to provide an additional safety check. PPP uses
+ Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
+ block. When decompressing, PPP checks that at the end of input packet,
+ inflate is waiting for these length bytes.
+ */
+int ZEXPORT inflateSyncPoint(strm)
+z_streamp strm;
+{
+ struct inflate_state FAR *state;
+
+ if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ return state->mode == STORED && state->bits == 0;
+}
+
+int ZEXPORT inflateCopy(dest, source)
+z_streamp dest;
+z_streamp source;
+{
+ struct inflate_state FAR *state;
+ struct inflate_state FAR *copy;
+ unsigned char FAR *window;
+ unsigned wsize;
+
+ /* check input */
+ if (inflateStateCheck(source) || dest == Z_NULL)
+ return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)source->state;
+
+ /* allocate space */
+ copy = (struct inflate_state FAR *)
+ ZALLOC(source, 1, sizeof(struct inflate_state));
+ if (copy == Z_NULL) return Z_MEM_ERROR;
+ window = Z_NULL;
+ if (state->window != Z_NULL) {
+ window = (unsigned char FAR *)
+ ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
+ if (window == Z_NULL) {
+ ZFREE(source, copy);
+ return Z_MEM_ERROR;
+ }
+ }
+
+ /* copy state */
+ zmemcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
+ zmemcpy((voidpf)copy, (voidpf)state, sizeof(struct inflate_state));
+ copy->strm = dest;
+ if (state->lencode >= state->codes &&
+ state->lencode <= state->codes + ENOUGH - 1) {
+ copy->lencode = copy->codes + (state->lencode - state->codes);
+ copy->distcode = copy->codes + (state->distcode - state->codes);
+ }
+ copy->next = copy->codes + (state->next - state->codes);
+ if (window != Z_NULL) {
+ wsize = 1U << state->wbits;
+ zmemcpy(window, state->window, wsize);
+ }
+ copy->window = window;
+ dest->state = (struct internal_state FAR *)copy;
+ return Z_OK;
+}
+
+int ZEXPORT inflateUndermine(strm, subvert)
+z_streamp strm;
+int subvert;
+{
+ struct inflate_state FAR *state;
+
+ if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+ state->sane = !subvert;
+ return Z_OK;
+#else
+ (void)subvert;
+ state->sane = 1;
+ return Z_DATA_ERROR;
+#endif
+}
+
+int ZEXPORT inflateValidate(strm, check)
+z_streamp strm;
+int check;
+{
+ struct inflate_state FAR *state;
+
+ if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ if (check && state->wrap)
+ state->wrap |= 4;
+ else
+ state->wrap &= ~4;
+ return Z_OK;
+}
+
+long ZEXPORT inflateMark(strm)
+z_streamp strm;
+{
+ struct inflate_state FAR *state;
+
+ if (inflateStateCheck(strm))
+ return -(1L << 16);
+ state = (struct inflate_state FAR *)strm->state;
+ return (long)(((unsigned long)((long)state->back)) << 16) +
+ (state->mode == COPY ? state->length :
+ (state->mode == MATCH ? state->was - state->length : 0));
+}
+
+unsigned long ZEXPORT inflateCodesUsed(strm)
+z_streamp strm;
+{
+ struct inflate_state FAR *state;
+ if (inflateStateCheck(strm)) return (unsigned long)-1;
+ state = (struct inflate_state FAR *)strm->state;
+ return (unsigned long)(state->next - state->codes);
+}
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