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infback.c
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/* infback.c -- inflate using a call-back interface
* Copyright (C) 1995-2016 Mark Adler
* For conditions of distribution and use, see copyright notice in zlib.h
*/
/*
This code is largely copied from inflate.c. Normally either infback.o or
inflate.o would be linked into an application--not both. The interface
with inffast.c is retained so that optimized assembler-coded versions of
inflate_fast() can be used with either inflate.c or infback.c.
*/
#include "zutil.h"
#include "inftrees.h"
#include "inflate.h"
#include "inffast.h"
/* function prototypes */
local void fixedtables OF((struct inflate_state FAR *state));
/*
strm provides memory allocation functions in zalloc and zfree, or
Z_NULL to use the library memory allocation functions.
windowBits is in the range 8..15, and window is a user-supplied
window and output buffer that is 2**windowBits bytes.
*/
int ZEXPORT inflateBackInit_(strm, windowBits, window, version, stream_size)
z_streamp strm;
int windowBits;
unsigned char FAR *window;
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 || window == Z_NULL ||
windowBits < 8 || windowBits > 15)
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->dmax = 32768U;
state->wbits = (uInt)windowBits;
state->wsize = 1U << windowBits;
state->window = window;
state->wnext = 0;
state->whave = 0;
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;
}
/* Macros for inflateBack(): */
/* Load returned state from inflate_fast() */
#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)
/* Set state from registers for inflate_fast() */
#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)
/* Assure that some input is available. If input is requested, but denied,
then return a Z_BUF_ERROR from inflateBack(). */
#define PULL() \
do { \
if (have == 0) { \
have = in(in_desc, &next); \
if (have == 0) { \
next = Z_NULL; \
ret = Z_BUF_ERROR; \
goto inf_leave; \
} \
} \
} while (0)
/* Get a byte of input into the bit accumulator, or return from inflateBack()
with an error if there is no input available. */
#define PULLBYTE() \
do { \
PULL(); \
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 inflateBack() with
an error. */
#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)
/* Assure that some output space is available, by writing out the window
if it's full. If the write fails, return from inflateBack() with a
Z_BUF_ERROR. */
#define ROOM() \
do { \
if (left == 0) { \
put = state->window; \
left = state->wsize; \
state->whave = left; \
if (out(out_desc, put, left)) { \
ret = Z_BUF_ERROR; \
goto inf_leave; \
} \
} \
} while (0)
/*
strm provides the memory allocation functions and window buffer on input,
and provides information on the unused input on return. For Z_DATA_ERROR
returns, strm will also provide an error message.
in() and out() are the call-back input and output functions. When
inflateBack() needs more input, it calls in(). When inflateBack() has
filled the window with output, or when it completes with data in the
window, it calls out() to write out the data. The application must not
change the provided input until in() is called again or inflateBack()
returns. The application must not change the window/output buffer until
inflateBack() returns.
in() and out() are called with a descriptor parameter provided in the
inflateBack() call. This parameter can be a structure that provides the
information required to do the read or write, as well as accumulated
information on the input and output such as totals and check values.
in() should return zero on failure. out() should return non-zero on
failure. If either in() or out() fails, than inflateBack() returns a
Z_BUF_ERROR. strm->next_in can be checked for Z_NULL to see whether it
was in() or out() that caused in the error. Otherwise, inflateBack()
returns Z_STREAM_END on success, Z_DATA_ERROR for an deflate format
error, or Z_MEM_ERROR if it could not allocate memory for the state.
inflateBack() can also return Z_STREAM_ERROR if the input parameters
are not correct, i.e. strm is Z_NULL or the state was not initialized.
*/
int ZEXPORT inflateBack(strm, in, in_desc, out, out_desc)
z_streamp strm;
in_func in;
void FAR *in_desc;
out_func out;
void FAR *out_desc;
{
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 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 */
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};
/* Check that the strm exists and that the state was initialized */
if (strm == Z_NULL || strm->state == Z_NULL)
return Z_STREAM_ERROR;
state = (struct inflate_state FAR *)strm->state;
/* Reset the state */
strm->msg = Z_NULL;
state->mode = TYPE;
state->last = 0;
state->whave = 0;
next = strm->next_in;
have = next != Z_NULL ? strm->avail_in : 0;
hold = 0;
bits = 0;
put = state->window;
left = state->wsize;
/* Inflate until end of block marked as last */
for (;;)
switch (state->mode) {
case TYPE:
/* determine and dispatch block type */
if (state->last) {
BYTEBITS();
state->mode = DONE;
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:
/* get and verify stored block length */
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();
/* copy stored block from input to output */
while (state->length != 0) {
copy = state->length;
PULL();
ROOM();
if (copy > have) copy = have;
if (copy > left) copy = left;
zmemcpy(put, next, copy);
have -= copy;
next += copy;
left -= copy;
put += copy;
state->length -= copy;
}
Tracev((stderr, "inflate: stored end\n"));
state->mode = TYPE;
break;
case TABLE:
/* get dynamic table entries descriptor */
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"));
/* get code length code lengths (not a typo) */
state->have = 0;
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"));
/* get length and distance code code lengths */
state->have = 0;
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 = (unsigned)(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 = (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:
/* use inflate_fast() if we have enough input and output */
if (have >= 6 && left >= 258) {
RESTORE();
if (state->whave < state->wsize)
state->whave = state->wsize - left;
inflate_fast(strm, state->wsize);
LOAD();
break;
}
/* get a literal, length, or end-of-block code */
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);
}
DROPBITS(here.bits);
state->length = (unsigned)here.val;
/* process literal */
if (here.op == 0) {
Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
"inflate: literal '%c'\n" :
"inflate: literal 0x%02x\n", here.val));
ROOM();
*put++ = (unsigned char)(state->length);
left--;
state->mode = LEN;
break;
}
/* process end of block */
if (here.op & 32) {
Tracevv((stderr, "inflate: end of block\n"));
state->mode = TYPE;
break;
}
/* invalid code */
if (here.op & 64) {
strm->msg = (char *)"invalid literal/length code";
state->mode = BAD;
break;
}
/* length code -- get extra bits, if any */
state->extra = (unsigned)(here.op) & 15;
if (state->extra != 0) {
NEEDBITS(state->extra);
state->length += BITS(state->extra);
DROPBITS(state->extra);
}
Tracevv((stderr, "inflate: length %u\n", state->length));
/* get distance code */
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);
}
DROPBITS(here.bits);
if (here.op & 64) {
strm->msg = (char *)"invalid distance code";
state->mode = BAD;
break;
}
state->offset = (unsigned)here.val;
/* get distance extra bits, if any */
state->extra = (unsigned)(here.op) & 15;
if (state->extra != 0) {
NEEDBITS(state->extra);
state->offset += BITS(state->extra);
DROPBITS(state->extra);
}
if (state->offset > state->wsize - (state->whave < state->wsize ?
left : 0)) {
strm->msg = (char *)"invalid distance too far back";
state->mode = BAD;
break;
}
Tracevv((stderr, "inflate: distance %u\n", state->offset));
/* copy match from window to output */
do {
ROOM();
copy = state->wsize - state->offset;
if (copy < left) {
from = put + copy;
copy = left - copy;
}
else {
from = put - state->offset;
copy = left;
}
if (copy > state->length) copy = state->length;
state->length -= copy;
left -= copy;
do {
*put++ = *from++;
} while (--copy);
} while (state->length != 0);
break;
case DONE:
/* inflate stream terminated properly -- write leftover output */
ret = Z_STREAM_END;
if (left < state->wsize) {
if (out(out_desc, state->window, state->wsize - left))
ret = Z_BUF_ERROR;
}
goto inf_leave;
case BAD:
ret = Z_DATA_ERROR;
goto inf_leave;
default: /* can't happen, but makes compilers happy */
ret = Z_STREAM_ERROR;
goto inf_leave;
}
/* Return unused input */
inf_leave:
strm->next_in = next;
strm->avail_in = have;
return ret;
}
int ZEXPORT inflateBackEnd(strm)
z_streamp strm;
{
if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
return Z_STREAM_ERROR;
ZFREE(strm, strm->state);
strm->state = Z_NULL;
Tracev((stderr, "inflate: end\n"));
return Z_OK;
}
local
#define local
Definition: gzguts.h:114
inflateBackInit_
int ZEXPORT inflateBackInit_(z_streamp strm, int windowBits, unsigned char FAR *window, const char *version, int stream_size)
Definition: infback.c:28
LOAD
#define LOAD()
Definition: infback.c:128
fixedtables
void fixedtables(struct inflate_state FAR *state)
Definition: infback.c:82
PULL
#define PULL()
Definition: infback.c:158
INITBITS
#define INITBITS()
Definition: infback.c:150
BITS
#define BITS(n)
Definition: infback.c:190
DROPBITS
#define DROPBITS(n)
Definition: infback.c:194
inflateBack
int ZEXPORT inflateBack(z_streamp strm, in_func in, void FAR *in_desc, out_func out, void FAR *out_desc)
Definition: infback.c:250
inflateBackEnd
int ZEXPORT inflateBackEnd(z_streamp strm)
Definition: infback.c:631
BYTEBITS
#define BYTEBITS()
Definition: infback.c:201
ROOM
#define ROOM()
Definition: infback.c:210
NEEDBITS
#define NEEDBITS(n)
Definition: infback.c:183
PULLBYTE
#define PULLBYTE()
Definition: infback.c:172
RESTORE
#define RESTORE()
Definition: infback.c:139
inflate_fast
void ZLIB_INTERNAL inflate_fast(z_streamp strm, unsigned start)
Definition: inffast.c:50
inffast.h
inffixed.h
inflate.h
TABLE
@ TABLE
Definition: inflate.h:37
STORED
@ STORED
Definition: inflate.h:34
DONE
@ DONE
Definition: inflate.h:49
TYPE
@ TYPE
Definition: inflate.h:32
BAD
@ BAD
Definition: inflate.h:50
LEN
@ LEN
Definition: inflate.h:41
inflate_table
int ZLIB_INTERNAL inflate_table(codetype type, unsigned short FAR *lens, unsigned codes, code FAR *FAR *table, unsigned FAR *bits, unsigned short FAR *work)
Definition: inftrees.c:32
inftrees.h
CODES
@ CODES
Definition: inftrees.h:55
LENS
@ LENS
Definition: inftrees.h:56
DISTS
@ DISTS
Definition: inftrees.h:57
code
Definition: inftrees.h:24
code::op
unsigned char op
Definition: inftrees.h:25
code::bits
unsigned char bits
Definition: inftrees.h:26
code::val
unsigned short val
Definition: inftrees.h:27
inflate_state
Definition: inflate.h:82
inflate_state::distcode
code const FAR * distcode
Definition: inflate.h:110
inflate_state::wnext
unsigned wnext
Definition: inflate.h:98
inflate_state::lenbits
unsigned lenbits
Definition: inflate.h:111
inflate_state::ndist
unsigned ndist
Definition: inflate.h:116
inflate_state::lencode
code const FAR * lencode
Definition: inflate.h:109
inflate_state::nlen
unsigned nlen
Definition: inflate.h:115
inflate_state::have
unsigned have
Definition: inflate.h:117
inflate_state::length
unsigned length
Definition: inflate.h:104
inflate_state::hold
unsigned long hold
Definition: inflate.h:101
inflate_state::extra
unsigned extra
Definition: inflate.h:107
inflate_state::ncode
unsigned ncode
Definition: inflate.h:114
inflate_state::strm
z_streamp strm
Definition: inflate.h:83
inflate_state::whave
unsigned whave
Definition: inflate.h:97
inflate_state::wbits
unsigned wbits
Definition: inflate.h:95
inflate_state::work
unsigned short work[288]
Definition: inflate.h:120
inflate_state::next
code FAR * next
Definition: inflate.h:118
inflate_state::distbits
unsigned distbits
Definition: inflate.h:112
inflate_state::mode
inflate_mode mode
Definition: inflate.h:84
inflate_state::window
unsigned char FAR * window
Definition: inflate.h:99
inflate_state::lens
unsigned short lens[320]
Definition: inflate.h:119
inflate_state::bits
unsigned bits
Definition: inflate.h:102
inflate_state::last
int last
Definition: inflate.h:85
inflate_state::wsize
unsigned wsize
Definition: inflate.h:96
inflate_state::dmax
unsigned dmax
Definition: inflate.h:90
inflate_state::offset
unsigned offset
Definition: inflate.h:105
inflate_state::codes
code codes[ENOUGH]
Definition: inflate.h:121
internal_state
Definition: deflate.h:100
internal_state::window
Bytef * window
Definition: deflate.h:119
z_stream_s
Definition: zlib.h:86
voidpf
Byte FAR * voidpf
Definition: zconf.h:413
ZEXPORT
#define ZEXPORT
Definition: zconf.h:380
uInt
unsigned int uInt
Definition: zconf.h:393
z_const
#define z_const
Definition: zconf.h:237
OF
#define OF(args)
Definition: zconf.h:292
FAR
#define FAR
Definition: zconf.h:387
Z_BUF_ERROR
#define Z_BUF_ERROR
Definition: zlib.h:184
ZLIB_VERSION
#define ZLIB_VERSION
Definition: zlib.h:40
z_streamp
z_stream FAR * z_streamp
Definition: zlib.h:108
Z_VERSION_ERROR
#define Z_VERSION_ERROR
Definition: zlib.h:185
Z_STREAM_END
#define Z_STREAM_END
Definition: zlib.h:178
Z_OK
#define Z_OK
Definition: zlib.h:177
Z_DATA_ERROR
#define Z_DATA_ERROR
Definition: zlib.h:182
Z_STREAM_ERROR
#define Z_STREAM_ERROR
Definition: zlib.h:181
Z_NULL
#define Z_NULL
Definition: zlib.h:212
Z_MEM_ERROR
#define Z_MEM_ERROR
Definition: zlib.h:183
zcfree
void ZLIB_INTERNAL zcfree(voidpf opaque, voidpf ptr)
Definition: zutil.c:315
zcalloc
voidpf ZLIB_INTERNAL zcalloc(voidpf opaque, unsigned items, unsigned size)
Definition: zutil.c:305
zmemcpy
void ZLIB_INTERNAL zmemcpy(Bytef *dest, const Bytef *source, uInt len)
Definition: zutil.c:149
zutil.h
ZALLOC
#define ZALLOC(strm, items, size)
Definition: zutil.h:262
Tracev
#define Tracev(x)
Definition: zutil.h:250
ZFREE
#define ZFREE(strm, addr)
Definition: zutil.h:264
Tracevv
#define Tracevv(x)
Definition: zutil.h:251