| /* inflate.c -- zlib decompression |
| * Copyright (C) 1995-2005 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 write == 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 void fixedtables OF((struct inflate_state FAR *state)); |
| local int updatewindow OF((z_streamp strm, unsigned out)); |
| #ifdef BUILDFIXED |
| void makefixed OF((void)); |
| #endif |
| local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf, |
| unsigned len)); |
| |
| int ZEXPORT inflateReset(strm) |
| z_streamp strm; |
| { |
| struct inflate_state FAR *state; |
| |
| if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
| state = (struct inflate_state FAR *)strm->state; |
| strm->total_in = strm->total_out = state->total = 0; |
| strm->msg = Z_NULL; |
| strm->adler = 1; /* to support ill-conceived Java test suite */ |
| state->mode = HEAD; |
| state->last = 0; |
| state->havedict = 0; |
| state->dmax = 32768U; |
| state->head = Z_NULL; |
| state->wsize = 0; |
| state->whave = 0; |
| state->write = 0; |
| state->hold = 0; |
| state->bits = 0; |
| state->lencode = state->distcode = state->next = state->codes; |
| Tracev((stderr, "inflate: reset\n")); |
| return Z_OK; |
| } |
| |
| int ZEXPORT inflatePrime(strm, bits, value) |
| z_streamp strm; |
| int bits; |
| int value; |
| { |
| struct inflate_state FAR *state; |
| |
| if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; |
| state = (struct inflate_state FAR *)strm->state; |
| if (bits > 16 || state->bits + bits > 32) return Z_STREAM_ERROR; |
| value &= (1L << bits) - 1; |
| state->hold += value << state->bits; |
| state->bits += bits; |
| return Z_OK; |
| } |
| |
| int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size) |
| z_streamp strm; |
| int windowBits; |
| const char *version; |
| int stream_size; |
| { |
| 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) { |
| strm->zalloc = zcalloc; |
| strm->opaque = (voidpf)0; |
| } |
| if (strm->zfree == (free_func)0) strm->zfree = zcfree; |
| 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; |
| if (windowBits < 0) { |
| state->wrap = 0; |
| windowBits = -windowBits; |
| } |
| else { |
| state->wrap = (windowBits >> 4) + 1; |
| #ifdef GUNZIP |
| if (windowBits < 48) windowBits &= 15; |
| #endif |
| } |
| if (windowBits < 8 || windowBits > 15) { |
| ZFREE(strm, state); |
| strm->state = Z_NULL; |
| return Z_STREAM_ERROR; |
| } |
| state->wbits = (unsigned)windowBits; |
| state->window = Z_NULL; |
| return inflateReset(strm); |
| } |
| |
| int ZEXPORT inflateInit_(strm, version, stream_size) |
| z_streamp strm; |
| const char *version; |
| int stream_size; |
| { |
| return inflateInit2_(strm, DEF_WBITS, version, stream_size); |
| } |
| |
| /* |
| 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}", 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, out) |
| z_streamp strm; |
| unsigned out; |
| { |
| struct inflate_state FAR *state; |
| unsigned copy, 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->write = 0; |
| state->whave = 0; |
| } |
| |
| /* copy state->wsize or less output bytes into the circular window */ |
| copy = out - strm->avail_out; |
| if (copy >= state->wsize) { |
| zmemcpy(state->window, strm->next_out - state->wsize, state->wsize); |
| state->write = 0; |
| state->whave = state->wsize; |
| } |
| else { |
| dist = state->wsize - state->write; |
| if (dist > copy) dist = copy; |
| zmemcpy(state->window + state->write, strm->next_out - copy, dist); |
| copy -= dist; |
| if (copy) { |
| zmemcpy(state->window, strm->next_out - copy, copy); |
| state->write = copy; |
| state->whave = state->wsize; |
| } |
| else { |
| state->write += dist; |
| if (state->write == state->wsize) state->write = 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, buf, len) \ |
| (state->flags ? crc32(check, buf, len) : adler32(check, buf, len)) |
| #else |
| # define UPDATE(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) |
| |
| /* Reverse the bytes in a 32-bit value */ |
| #define REVERSE(q) \ |
| ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \ |
| (((q) & 0xff00) << 8) + (((q) & 0xff) << 24)) |
| |
| /* |
| 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; |
| 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 this; /* 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 (strm == Z_NULL || strm->state == Z_NULL || 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 */ |
| state->check = crc32(0L, Z_NULL, 0); |
| CRC2(state->check, hold); |
| INITBITS(); |
| state->mode = FLAGS; |
| break; |
| } |
| state->flags = 0; /* expect zlib header */ |
| 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 (len > state->wbits) { |
| strm->msg = (char *)"invalid window size"; |
| state->mode = BAD; |
| break; |
| } |
| state->dmax = 1U << len; |
| 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) CRC2(state->check, hold); |
| INITBITS(); |
| state->mode = TIME; |
| case TIME: |
| NEEDBITS(32); |
| if (state->head != Z_NULL) |
| state->head->time = hold; |
| if (state->flags & 0x0200) CRC4(state->check, hold); |
| INITBITS(); |
| state->mode = OS; |
| 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) CRC2(state->check, hold); |
| INITBITS(); |
| state->mode = EXLEN; |
| 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) CRC2(state->check, hold); |
| INITBITS(); |
| } |
| else if (state->head != Z_NULL) |
| state->head->extra = Z_NULL; |
| state->mode = EXTRA; |
| 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->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; |
| 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++] = len; |
| } while (len && copy < have); |
| if (state->flags & 0x0200) |
| 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; |
| 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++] = len; |
| } while (len && copy < have); |
| if (state->flags & 0x0200) |
| 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; |
| case HCRC: |
| if (state->flags & 0x0200) { |
| NEEDBITS(16); |
| if (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 = REVERSE(hold); |
| INITBITS(); |
| state->mode = DICT; |
| case DICT: |
| if (state->havedict == 0) { |
| RESTORE(); |
| return Z_NEED_DICT; |
| } |
| strm->adler = state->check = adler32(0L, Z_NULL, 0); |
| state->mode = TYPE; |
| case TYPE: |
| if (flush == Z_BLOCK) goto inf_leave; |
| 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 */ |
| 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; |
| 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; |
| 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 = (code const 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; |
| case CODELENS: |
| while (state->have < state->nlen + state->ndist) { |
| for (;;) { |
| this = state->lencode[BITS(state->lenbits)]; |
| if ((unsigned)(this.bits) <= bits) break; |
| PULLBYTE(); |
| } |
| if (this.val < 16) { |
| NEEDBITS(this.bits); |
| DROPBITS(this.bits); |
| state->lens[state->have++] = this.val; |
| } |
| else { |
| if (this.val == 16) { |
| NEEDBITS(this.bits + 2); |
| DROPBITS(this.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 (this.val == 17) { |
| NEEDBITS(this.bits + 3); |
| DROPBITS(this.bits); |
| len = 0; |
| copy = 3 + BITS(3); |
| DROPBITS(3); |
| } |
| else { |
| NEEDBITS(this.bits + 7); |
| DROPBITS(this.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; |
| |
| /* build code tables */ |
| state->next = state->codes; |
| state->lencode = (code const 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 = (code const 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; |
| case LEN: |
| if (have >= 6 && left >= 258) { |
| RESTORE(); |
| inflate_fast(strm, out); |
| LOAD(); |
| break; |
| } |
| for (;;) { |
| this = state->lencode[BITS(state->lenbits)]; |
| if ((unsigned)(this.bits) <= bits) break; |
| PULLBYTE(); |
| } |
| if (this.op && (this.op & 0xf0) == 0) { |
| last = this; |
| for (;;) { |
| this = state->lencode[last.val + |
| (BITS(last.bits + last.op) >> last.bits)]; |
| if ((unsigned)(last.bits + this.bits) <= bits) break; |
| PULLBYTE(); |
| } |
| DROPBITS(last.bits); |
| } |
| DROPBITS(this.bits); |
| state->length = (unsigned)this.val; |
| if ((int)(this.op) == 0) { |
| Tracevv((stderr, this.val >= 0x20 && this.val < 0x7f ? |
| "inflate: literal '%c'\n" : |
| "inflate: literal 0x%02x\n", this.val)); |
| state->mode = LIT; |
| break; |
| } |
| if (this.op & 32) { |
| Tracevv((stderr, "inflate: end of block\n")); |
| state->mode = TYPE; |
| break; |
| } |
| if (this.op & 64) { |
| strm->msg = (char *)"invalid literal/length code"; |
| state->mode = BAD; |
| break; |
| } |
| state->extra = (unsigned)(this.op) & 15; |
| state->mode = LENEXT; |
| case LENEXT: |
| if (state->extra) { |
| NEEDBITS(state->extra); |
| state->length += BITS(state->extra); |
| DROPBITS(state->extra); |
| } |
| Tracevv((stderr, "inflate: length %u\n", state->length)); |
| state->mode = DIST; |
| case DIST: |
| for (;;) { |
| this = state->distcode[BITS(state->distbits)]; |
| if ((unsigned)(this.bits) <= bits) break; |
| PULLBYTE(); |
| } |
| if ((this.op & 0xf0) == 0) { |
| last = this; |
| for (;;) { |
| this = state->distcode[last.val + |
| (BITS(last.bits + last.op) >> last.bits)]; |
| if ((unsigned)(last.bits + this.bits) <= bits) break; |
| PULLBYTE(); |
| } |
| DROPBITS(last.bits); |
| } |
| DROPBITS(this.bits); |
| if (this.op & 64) { |
| strm->msg = (char *)"invalid distance code"; |
| state->mode = BAD; |
| break; |
| } |
| state->offset = (unsigned)this.val; |
| state->extra = (unsigned)(this.op) & 15; |
| state->mode = DISTEXT; |
| case DISTEXT: |
| if (state->extra) { |
| NEEDBITS(state->extra); |
| state->offset += BITS(state->extra); |
| DROPBITS(state->extra); |
| } |
| #ifdef INFLATE_STRICT |
| if (state->offset > state->dmax) { |
| strm->msg = (char *)"invalid distance too far back"; |
| state->mode = BAD; |
| break; |
| } |
| #endif |
| if (state->offset > state->whave + out - left) { |
| strm->msg = (char *)"invalid distance too far back"; |
| state->mode = BAD; |
| break; |
| } |
| Tracevv((stderr, "inflate: distance %u\n", state->offset)); |
| state->mode = MATCH; |
| 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->write) { |
| copy -= state->write; |
| from = state->window + (state->wsize - copy); |
| } |
| else |
| from = state->window + (state->write - 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 (out) |
| strm->adler = state->check = |
| UPDATE(state->check, put - out, out); |
| out = left; |
| if (( |
| #ifdef GUNZIP |
| state->flags ? hold : |
| #endif |
| REVERSE(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; |
| case LENGTH: |
| if (state->wrap && state->flags) { |
| NEEDBITS(32); |
| if (hold != (state->total & 0xffffffffUL)) { |
| strm->msg = (char *)"incorrect length check"; |
| state->mode = BAD; |
| break; |
| } |
| INITBITS(); |
| Tracev((stderr, "inflate: length matches trailer\n")); |
| } |
| #endif |
| state->mode = DONE; |
| 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: |
| 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 || (state->mode < CHECK && out != strm->avail_out)) |
| if (updatewindow(strm, out)) { |
| state->mode = MEMORYSIZE; |
| 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 && out) |
| strm->adler = state->check = |
| UPDATE(state->check, strm->next_out - out, out); |
| strm->data_type = state->bits + (state->last ? 64 : 0) + |
| (state->mode == TYPE ? 128 : 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 (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0) |
| 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 inflateSetDictionary(strm, dictionary, dictLength) |
| z_streamp strm; |
| const Bytef *dictionary; |
| uInt dictLength; |
| { |
| struct inflate_state FAR *state; |
| unsigned long id; |
| |
| /* check state */ |
| if (strm == Z_NULL || strm->state == Z_NULL) 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 id */ |
| if (state->mode == DICT) { |
| id = adler32(0L, Z_NULL, 0); |
| id = adler32(id, dictionary, dictLength); |
| if (id != state->check) |
| return Z_DATA_ERROR; |
| } |
| |
| /* copy dictionary to window */ |
| if (updatewindow(strm, strm->avail_out)) { |
| state->mode = MEMORYSIZE; |
| return Z_MEM_ERROR; |
| } |
| if (dictLength > state->wsize) { |
| zmemcpy(state->window, dictionary + dictLength - state->wsize, |
| state->wsize); |
| state->whave = state->wsize; |
| } |
| else { |
| zmemcpy(state->window + state->wsize - dictLength, dictionary, |
| dictLength); |
| state->whave = dictLength; |
| } |
| 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 (strm == Z_NULL || strm->state == Z_NULL) 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; |
| 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 */ |
| 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 (strm == Z_NULL || strm->state == Z_NULL) 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; |
| in = strm->total_in; out = strm->total_out; |
| inflateReset(strm); |
| strm->total_in = in; strm->total_out = out; |
| 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 (strm == Z_NULL || strm->state == Z_NULL) 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 (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL || |
| source->zalloc == (alloc_func)0 || source->zfree == (free_func)0) |
| 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(dest, source, sizeof(z_stream)); |
| zmemcpy(copy, state, sizeof(struct inflate_state)); |
| 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; |
| } |