645 lines
22 KiB
C
645 lines
22 KiB
C
/* infback.c -- inflate using a call-back interface
|
|
* Copyright (C) 1995-2022 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;
|
|
state->sane = 1;
|
|
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;
|
|
/* fallthrough */
|
|
|
|
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 */
|
|
ret = Z_STREAM_END;
|
|
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;
|
|
}
|
|
|
|
/* Write leftover output and return unused input */
|
|
inf_leave:
|
|
if (left < state->wsize) {
|
|
if (out(out_desc, state->window, state->wsize - left) &&
|
|
ret == Z_STREAM_END)
|
|
ret = Z_BUF_ERROR;
|
|
}
|
|
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;
|
|
}
|