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cosmopolitan/third_party/zlib/inflate.c

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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:4;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=4 sts=4 sw=4 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 1995-2016 Mark Adler │
│ Use of this source code is governed by the BSD-style licenses that can │
│ be found in the third_party/zlib/LICENSE file. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/str/str.h"
#include "third_party/zlib/chunkcopy.h"
#include "third_party/zlib/inffast.h"
#include "third_party/zlib/inflate.h"
#include "third_party/zlib/inftrees.h"
#include "third_party/zlib/internal.h"
#include "third_party/zlib/zutil.h"
asm(".ident\t\"\\n\\n\
zlib (zlib License)\\n\
Copyright 1995-2017 Jean-loup Gailly and Mark Adler\"");
asm(".include \"libc/disclaimer.inc\"");
/**
* @fileoverview zlib decompression
*
* 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 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.
*/
#ifdef MAKEFIXED
#ifndef BUILDFIXED
#define BUILDFIXED
#endif
#endif
/* permutation of code lengths */
static const unsigned short kZlibDeflateOrder[19] = {
16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
static int inflateStateCheck(z_streamp strm);
static void fixedtables(struct InflateState *state);
static int updatewindow(z_streamp strm, const unsigned char *end,
unsigned copy);
static unsigned syncsearch(unsigned *have, const unsigned char *buf,
unsigned len);
#ifdef BUILDFIXED
void makefixed(void);
#endif
static int inflateStateCheck(z_streamp strm) {
struct InflateState *state;
if (strm == Z_NULL || strm->zalloc == (alloc_func)0 ||
strm->zfree == (free_func)0)
return 1;
state = (struct InflateState *)strm->state;
if (state == Z_NULL || state->strm != strm || state->mode < HEAD ||
state->mode > SYNC)
return 1;
return 0;
}
int inflateResetKeep(z_streamp strm) {
struct InflateState *state;
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
state = (struct InflateState *)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->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 inflateReset(z_streamp strm) {
struct InflateState *state;
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
state = (struct InflateState *)strm->state;
state->wsize = 0;
state->whave = 0;
state->wnext = 0;
return inflateResetKeep(strm);
}
int inflateReset2(z_streamp strm, int windowBits) {
int wrap;
struct InflateState *state;
/* get the state */
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
state = (struct InflateState *)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 inflateInit2(z_streamp strm, int windowBits) {
int ret;
struct InflateState *state;
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 InflateState *)ZALLOC(strm, 1, sizeof(struct InflateState));
if (state == Z_NULL) return Z_MEM_ERROR;
Tracev((stderr, "inflate: allocated\n"));
strm->state = (struct DeflateState *)state;
state->strm = strm;
state->window = Z_NULL;
state->mode = HEAD; /* to pass state test in inflateReset2() */
state->check = 1L; /* 1L is the result of adler32() zero length data */
ret = inflateReset2(strm, windowBits);
if (ret != Z_OK) {
ZFREE(strm, state);
strm->state = Z_NULL;
}
return ret;
}
int inflatePrime(z_streamp strm, int bits, int value) {
struct InflateState *state;
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
state = (struct InflateState *)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;
}
/**
* Returns 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.
*/
static void fixedtables(struct InflateState *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;
}
state->lencode = lenfix;
state->distcode = distfix;
#else /* !BUILDFIXED */
state->lencode = kZlibLenfix;
state->distcode = kZlibDistfix;
#endif /* BUILDFIXED */
state->lenbits = 9;
state->distbits = 5;
}
#ifdef MAKEFIXED
#include "libc/stdio/stdio.h"
/**
* Writes 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(void) {
unsigned low, size;
struct InflateState 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 zcode 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 zcode 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 */
/**
* Updates window with 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.
*/
static int updatewindow(z_streamp strm, const Bytef *end, unsigned copy) {
struct InflateState *state;
unsigned dist;
state = (struct InflateState *)strm->state;
/* if it hasn't been done already, allocate space for the window */
if (state->window == Z_NULL) {
unsigned wsize = 1U << state->wbits;
state->window = (unsigned char *)ZALLOC(strm, wsize + CHUNKCOPY_CHUNK_SIZE,
sizeof(unsigned char));
if (state->window == Z_NULL) return 1;
#ifdef INFLATE_CLEAR_UNUSED_UNDEFINED
/* Copies from the overflow portion of this buffer are undefined and
may cause analysis tools to raise a warning if we don't initialize
it. However, this undefined data overwrites other undefined data
and is subsequently either overwritten or left deliberately
undefined at the end of decode; so there's really no point.
*/
memset(state->window + wsize, 0, CHUNKCOPY_CHUNK_SIZE);
#endif
}
/* 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) {
memcpy(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;
memcpy(state->window + state->wnext, end - copy, dist);
copy -= dist;
if (copy) {
memcpy(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, 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)
/**
* 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 inflate(z_streamp strm, int flush) {
struct InflateState *state;
const unsigned char *next; /* next input */
unsigned char *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 *from; /* where to copy match bytes from */
struct zcode here; /* current decoding table entry */
struct zcode 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
if (inflateStateCheck(strm) || strm->next_out == Z_NULL ||
(strm->next_in == Z_NULL && strm->avail_in != 0)) {
return Z_STREAM_ERROR;
}
state = (struct InflateState *)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;
}
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 (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;
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;
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;
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;
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;
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;
memcpy(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;
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;
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;
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;
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 || flush == Z_TREES) 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 */
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;
case COPY_:
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;
memcpy(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[kZlibDeflateOrder[state->have++]] =
(unsigned short)BITS(3);
DROPBITS(3);
}
while (state->have < 19) {
state->lens[kZlibDeflateOrder[state->have++]] = 0;
}
state->next = state->codes;
state->lencode = (const struct zcode *)(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 (;;) {
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 struct zcode *)(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 struct zcode *)(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;
case LEN_:
state->mode = LEN;
case LEN:
if (have >= INFLATE_FAST_MIN_INPUT && left >= INFLATE_FAST_MIN_OUTPUT) {
RESTORE();
inflate_fast_chunk(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;
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;
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;
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;
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;
if (copy > left) copy = left;
put = chunkcopy_safe(put, from, copy, put + left);
} else { /* copy from output */
copy = state->length;
if (copy > left) copy = left;
put = chunkcopy_lapped_safe(put, state->offset, copy, put + left);
}
left -= copy;
state->length -= 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(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;
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:
/* We write a defined value in the unused space to help mark
* where the stream has ended. We don't use zeros as that can
* mislead clients relying on undefined behavior (i.e. assuming
* that the data is over when the buffer has a zero/null value).
*/
if (left >= CHUNKCOPY_CHUNK_SIZE) {
memset(put, 0x55, CHUNKCOPY_CHUNK_SIZE);
} else {
memset(put, 0x55, left);
}
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(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 inflateEnd(z_streamp strm) {
struct InflateState *state;
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
state = (struct InflateState *)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 inflateGetDictionary(z_streamp strm, Bytef *dictionary, uInt *dictLength) {
struct InflateState *state;
/* check state */
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
state = (struct InflateState *)strm->state;
/* copy dictionary */
if (state->whave && dictionary != Z_NULL) {
memcpy(dictionary, state->window + state->wnext,
state->whave - state->wnext);
memcpy(dictionary + state->whave - state->wnext, state->window,
state->wnext);
}
if (dictLength != Z_NULL) *dictLength = state->whave;
return Z_OK;
}
int inflateSetDictionary(z_streamp strm, const Bytef *dictionary,
uInt dictLength) {
struct InflateState *state;
unsigned long dictid;
int ret;
/* check state */
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
state = (struct InflateState *)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 inflateGetHeader(z_streamp strm, gz_headerp head) {
struct InflateState *state;
/* check state */
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
state = (struct InflateState *)strm->state;
if ((state->wrap & 2) == 0) return Z_STREAM_ERROR;
/* save header structure */
state->head = head;
head->done = 0;
return Z_OK;
}
/**
* Searches 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.
*/
static unsigned syncsearch(unsigned *have, const unsigned char *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 inflateSync(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 InflateState *state;
/* check parameters */
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
state = (struct InflateState *)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 inflateSyncPoint(z_streamp strm) {
struct InflateState *state;
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
state = (struct InflateState *)strm->state;
return state->mode == STORED && state->bits == 0;
}
int inflateCopy(z_streamp dest, z_streamp source) {
struct InflateState *state;
struct InflateState *copy;
unsigned char *window;
unsigned wsize;
/* check input */
if (inflateStateCheck(source) || dest == Z_NULL) return Z_STREAM_ERROR;
state = (struct InflateState *)source->state;
/* allocate space */
copy = (struct InflateState *)ZALLOC(source, 1, sizeof(struct InflateState));
if (copy == Z_NULL) return Z_MEM_ERROR;
window = Z_NULL;
if (state->window != Z_NULL) {
window = (unsigned char *)ZALLOC(source, 1U << state->wbits,
sizeof(unsigned char));
if (window == Z_NULL) {
ZFREE(source, copy);
return Z_MEM_ERROR;
}
}
/* copy state */
memcpy((voidpf)dest, (voidpf)source, sizeof(z_stream));
memcpy((voidpf)copy, (voidpf)state, sizeof(struct InflateState));
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;
memcpy(window, state->window, wsize);
}
copy->window = window;
dest->state = (struct DeflateState *)copy;
return Z_OK;
}
int inflateUndermine(z_streamp strm, int subvert) {
struct InflateState *state;
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
state = (struct InflateState *)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 inflateValidate(z_streamp strm, int check) {
struct InflateState *state;
if (inflateStateCheck(strm)) return Z_STREAM_ERROR;
state = (struct InflateState *)strm->state;
if (check)
state->wrap |= 4;
else
state->wrap &= ~4;
return Z_OK;
}
long inflateMark(z_streamp strm) {
struct InflateState *state;
if (inflateStateCheck(strm)) return -(1L << 16);
state = (struct InflateState *)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 inflateCodesUsed(z_streamp strm) {
struct InflateState *state;
if (inflateStateCheck(strm)) return (unsigned long)-1;
state = (struct InflateState *)strm->state;
return (unsigned long)(state->next - state->codes);
}
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