busybox/archival/libunarchive/decompress_unzip.c
2003-02-09 12:00:17 +00:00

1041 lines
29 KiB
C

/* vi: set sw=4 ts=4: */
/*
* gunzip implementation for busybox
*
* Based on GNU gzip v1.2.4 Copyright (C) 1992-1993 Jean-loup Gailly.
*
* Originally adjusted for busybox by Sven Rudolph <sr1@inf.tu-dresden.de>
* based on gzip sources
*
* Adjusted further by Erik Andersen <andersee@debian.org> to support
* files as well as stdin/stdout, and to generally behave itself wrt
* command line handling.
*
* General cleanup to better adhere to the style guide and make use of standard
* busybox functions by Glenn McGrath <bug1@optushome.com.au>
*
* read_gz interface + associated hacking by Laurence Anderson
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*
* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
* Copyright (C) 1992-1993 Jean-loup Gailly
* The unzip code was written and put in the public domain by Mark Adler.
* Portions of the lzw code are derived from the public domain 'compress'
* written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
* Ken Turkowski, Dave Mack and Peter Jannesen.
*
* See the license_msg below and the file COPYING for the software license.
* See the file algorithm.doc for the compression algorithms and file formats.
*/
#if 0
static char *license_msg[] = {
" Copyright (C) 1992-1993 Jean-loup Gailly",
" This program is free software; you can redistribute it and/or modify",
" it under the terms of the GNU General Public License as published by",
" the Free Software Foundation; either version 2, or (at your option)",
" any later version.",
"",
" This program is distributed in the hope that it will be useful,",
" but WITHOUT ANY WARRANTY; without even the implied warranty of",
" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the",
" GNU General Public License for more details.",
"",
" You should have received a copy of the GNU General Public License",
" along with this program; if not, write to the Free Software",
" Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.",
0
};
#endif
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include "config.h"
#include "busybox.h"
#include "unarchive.h"
typedef struct huft_s {
unsigned char e; /* number of extra bits or operation */
unsigned char b; /* number of bits in this code or subcode */
union {
unsigned short n; /* literal, length base, or distance base */
struct huft_s *t; /* pointer to next level of table */
} v;
} huft_t;
static int gunzip_src_fd;
unsigned int gunzip_bytes_out; /* number of output bytes */
static unsigned int gunzip_outbuf_count; /* bytes in output buffer */
/* gunzip_window size--must be a power of two, and
* at least 32K for zip's deflate method */
static const int gunzip_wsize = 0x8000;
static unsigned char *gunzip_window;
static unsigned int *gunzip_crc_table;
unsigned int gunzip_crc;
/* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
#define BMAX 16 /* maximum bit length of any code (16 for explode) */
#define N_MAX 288 /* maximum number of codes in any set */
/* bitbuffer */
static unsigned int gunzip_bb; /* bit buffer */
static unsigned char gunzip_bk; /* bits in bit buffer */
/* These control the size of the bytebuffer */
#define BYTEBUFFER_MAX 0x8000
static unsigned char *bytebuffer = NULL;
static unsigned int bytebuffer_offset = 0;
static unsigned int bytebuffer_size = 0;
static const unsigned short mask_bits[] = {
0x0000, 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
};
/* Copy lengths for literal codes 257..285 */
static const unsigned short cplens[] = {
3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
};
/* note: see note #13 above about the 258 in this list. */
/* Extra bits for literal codes 257..285 */
static const unsigned char cplext[] = {
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5,
5, 5, 5, 0, 99, 99
}; /* 99==invalid */
/* Copy offsets for distance codes 0..29 */
static const unsigned short cpdist[] = {
1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513,
769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577
};
/* Extra bits for distance codes */
static const unsigned char cpdext[] = {
0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10,
11, 11, 12, 12, 13, 13
};
/* Tables for deflate from PKZIP's appnote.txt. */
/* Order of the bit length code lengths */
static const unsigned char border[] = {
16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
};
static void fill_bytebuffer(void)
{
if (bytebuffer_offset >= bytebuffer_size) {
/* Leave the first 4 bytes empty so we can always unwind the bitbuffer
* to the front of the bytebuffer, leave 4 bytes free at end of tail
* so we can easily top up buffer in check_trailer_gzip() */
bytebuffer_size = 4 + xread(gunzip_src_fd, &bytebuffer[4], BYTEBUFFER_MAX - 8);
bytebuffer_offset = 4;
}
}
static unsigned int fill_bitbuffer(unsigned int bitbuffer, unsigned int *current, const unsigned int required)
{
while (*current < required) {
fill_bytebuffer();
bitbuffer |= ((unsigned int) bytebuffer[bytebuffer_offset]) << *current;
bytebuffer_offset++;
*current += 8;
}
return(bitbuffer);
}
static void make_gunzip_crc_table(void)
{
const unsigned int poly = 0xedb88320; /* polynomial exclusive-or pattern */
unsigned short i; /* counter for all possible eight bit values */
/* initial shift register value */
gunzip_crc = 0xffffffffL;
gunzip_crc_table = (unsigned int *) malloc(256 * sizeof(unsigned int));
/* Compute and print table of CRC's, five per line */
for (i = 0; i < 256; i++) {
unsigned int table_entry; /* crc shift register */
unsigned char k; /* byte being shifted into crc apparatus */
table_entry = i;
/* The idea to initialize the register with the byte instead of
* zero was stolen from Haruhiko Okumura's ar002
*/
for (k = 8; k; k--) {
if (table_entry & 1) {
table_entry = (table_entry >> 1) ^ poly;
} else {
table_entry >>= 1;
}
}
gunzip_crc_table[i] = table_entry;
}
}
/*
* Free the malloc'ed tables built by huft_build(), which makes a linked
* list of the tables it made, with the links in a dummy first entry of
* each table.
* t: table to free
*/
static int huft_free(huft_t * t)
{
huft_t *p;
huft_t *q;
/* Go through linked list, freeing from the malloced (t[-1]) address. */
p = t;
while (p != (huft_t *) NULL) {
q = (--p)->v.t;
free((char *) p);
p = q;
}
return 0;
}
/* Given a list of code lengths and a maximum table size, make a set of
* tables to decode that set of codes. Return zero on success, one if
* the given code set is incomplete (the tables are still built in this
* case), two if the input is invalid (all zero length codes or an
* oversubscribed set of lengths), and three if not enough memory.
*
* b: code lengths in bits (all assumed <= BMAX)
* n: number of codes (assumed <= N_MAX)
* s: number of simple-valued codes (0..s-1)
* d: list of base values for non-simple codes
* e: list of extra bits for non-simple codes
* t: result: starting table
* m: maximum lookup bits, returns actual
*/
static int huft_build(unsigned int *b, const unsigned int n,
const unsigned int s, const unsigned short *d,
const unsigned char *e, huft_t ** t, int *m)
{
unsigned a; /* counter for codes of length k */
unsigned c[BMAX + 1]; /* bit length count table */
unsigned f; /* i repeats in table every f entries */
int g; /* maximum code length */
int h; /* table level */
register unsigned i; /* counter, current code */
register unsigned j; /* counter */
register int k; /* number of bits in current code */
int l; /* bits per table (returned in m) */
register unsigned *p; /* pointer into c[], b[], or v[] */
register huft_t *q; /* points to current table */
huft_t r; /* table entry for structure assignment */
huft_t *u[BMAX]; /* table stack */
unsigned v[N_MAX]; /* values in order of bit length */
register int w; /* bits before this table == (l * h) */
unsigned x[BMAX + 1]; /* bit offsets, then code stack */
unsigned *xp; /* pointer into x */
int y; /* number of dummy codes added */
unsigned z; /* number of entries in current table */
/* Generate counts for each bit length */
memset((void *) (c), 0, sizeof(c));
p = b;
i = n;
do {
c[*p]++; /* assume all entries <= BMAX */
p++; /* Can't combine with above line (Solaris bug) */
} while (--i);
if (c[0] == n) { /* null input--all zero length codes */
*t = (huft_t *) NULL;
*m = 0;
return 0;
}
/* Find minimum and maximum length, bound *m by those */
l = *m;
for (j = 1; j <= BMAX; j++) {
if (c[j]) {
break;
}
}
k = j; /* minimum code length */
if ((unsigned) l < j) {
l = j;
}
for (i = BMAX; i; i--) {
if (c[i]) {
break;
}
}
g = i; /* maximum code length */
if ((unsigned) l > i) {
l = i;
}
*m = l;
/* Adjust last length count to fill out codes, if needed */
for (y = 1 << j; j < i; j++, y <<= 1) {
if ((y -= c[j]) < 0) {
return 2; /* bad input: more codes than bits */
}
}
if ((y -= c[i]) < 0) {
return 2;
}
c[i] += y;
/* Generate starting offsets into the value table for each length */
x[1] = j = 0;
p = c + 1;
xp = x + 2;
while (--i) { /* note that i == g from above */
*xp++ = (j += *p++);
}
/* Make a table of values in order of bit lengths */
p = b;
i = 0;
do {
if ((j = *p++) != 0) {
v[x[j]++] = i;
}
} while (++i < n);
/* Generate the Huffman codes and for each, make the table entries */
x[0] = i = 0; /* first Huffman code is zero */
p = v; /* grab values in bit order */
h = -1; /* no tables yet--level -1 */
w = -l; /* bits decoded == (l * h) */
u[0] = (huft_t *) NULL; /* just to keep compilers happy */
q = (huft_t *) NULL; /* ditto */
z = 0; /* ditto */
/* go through the bit lengths (k already is bits in shortest code) */
for (; k <= g; k++) {
a = c[k];
while (a--) {
/* here i is the Huffman code of length k bits for value *p */
/* make tables up to required level */
while (k > w + l) {
h++;
w += l; /* previous table always l bits */
/* compute minimum size table less than or equal to l bits */
z = (z = g - w) > (unsigned) l ? l : z; /* upper limit on table size */
if ((f = 1 << (j = k - w)) > a + 1) { /* try a k-w bit table *//* too few codes for k-w bit table */
f -= a + 1; /* deduct codes from patterns left */
xp = c + k;
while (++j < z) { /* try smaller tables up to z bits */
if ((f <<= 1) <= *++xp) {
break; /* enough codes to use up j bits */
}
f -= *xp; /* else deduct codes from patterns */
}
}
z = 1 << j; /* table entries for j-bit table */
/* allocate and link in new table */
q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t));
*t = q + 1; /* link to list for huft_free() */
*(t = &(q->v.t)) = NULL;
u[h] = ++q; /* table starts after link */
/* connect to last table, if there is one */
if (h) {
x[h] = i; /* save pattern for backing up */
r.b = (unsigned char) l; /* bits to dump before this table */
r.e = (unsigned char) (16 + j); /* bits in this table */
r.v.t = q; /* pointer to this table */
j = i >> (w - l); /* (get around Turbo C bug) */
u[h - 1][j] = r; /* connect to last table */
}
}
/* set up table entry in r */
r.b = (unsigned char) (k - w);
if (p >= v + n) {
r.e = 99; /* out of values--invalid code */
} else if (*p < s) {
r.e = (unsigned char) (*p < 256 ? 16 : 15); /* 256 is end-of-block code */
r.v.n = (unsigned short) (*p); /* simple code is just the value */
p++; /* one compiler does not like *p++ */
} else {
r.e = (unsigned char) e[*p - s]; /* non-simple--look up in lists */
r.v.n = d[*p++ - s];
}
/* fill code-like entries with r */
f = 1 << (k - w);
for (j = i >> w; j < z; j += f) {
q[j] = r;
}
/* backwards increment the k-bit code i */
for (j = 1 << (k - 1); i & j; j >>= 1) {
i ^= j;
}
i ^= j;
/* backup over finished tables */
while ((i & ((1 << w) - 1)) != x[h]) {
h--; /* don't need to update q */
w -= l;
}
}
}
/* Return true (1) if we were given an incomplete table */
return y != 0 && g != 1;
}
/*
* inflate (decompress) the codes in a deflated (compressed) block.
* Return an error code or zero if it all goes ok.
*
* tl, td: literal/length and distance decoder tables
* bl, bd: number of bits decoded by tl[] and td[]
*/
static int inflate_codes(huft_t * my_tl, huft_t * my_td, const unsigned int my_bl, const unsigned int my_bd, int setup)
{
static unsigned int e; /* table entry flag/number of extra bits */
static unsigned int n, d; /* length and index for copy */
static unsigned int w; /* current gunzip_window position */
static huft_t *t; /* pointer to table entry */
static unsigned int ml, md; /* masks for bl and bd bits */
static unsigned int b; /* bit buffer */
static unsigned int k; /* number of bits in bit buffer */
static huft_t *tl, *td;
static unsigned int bl, bd;
static int resumeCopy = 0;
if (setup) { // 1st time we are called, copy in variables
tl = my_tl;
td = my_td;
bl = my_bl;
bd = my_bd;
/* make local copies of globals */
b = gunzip_bb; /* initialize bit buffer */
k = gunzip_bk;
w = gunzip_outbuf_count; /* initialize gunzip_window position */
/* inflate the coded data */
ml = mask_bits[bl]; /* precompute masks for speed */
md = mask_bits[bd];
return 0; // Don't actually do anything the first time
}
if (resumeCopy) goto do_copy;
while (1) { /* do until end of block */
b = fill_bitbuffer(b, &k, bl);
if ((e = (t = tl + ((unsigned) b & ml))->e) > 16)
do {
if (e == 99) {
error_msg_and_die("inflate_codes error 1");;
}
b >>= t->b;
k -= t->b;
e -= 16;
b = fill_bitbuffer(b, &k, e);
} while ((e =
(t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
b >>= t->b;
k -= t->b;
if (e == 16) { /* then it's a literal */
gunzip_window[w++] = (unsigned char) t->v.n;
if (w == gunzip_wsize) {
gunzip_outbuf_count = (w);
//flush_gunzip_window();
w = 0;
return 1; // We have a block to read
}
} else { /* it's an EOB or a length */
/* exit if end of block */
if (e == 15) {
break;
}
/* get length of block to copy */
b = fill_bitbuffer(b, &k, e);
n = t->v.n + ((unsigned) b & mask_bits[e]);
b >>= e;
k -= e;
/* decode distance of block to copy */
b = fill_bitbuffer(b, &k, bd);
if ((e = (t = td + ((unsigned) b & md))->e) > 16)
do {
if (e == 99)
error_msg_and_die("inflate_codes error 2");;
b >>= t->b;
k -= t->b;
e -= 16;
b = fill_bitbuffer(b, &k, e);
} while ((e =
(t =
t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
b >>= t->b;
k -= t->b;
b = fill_bitbuffer(b, &k, e);
d = w - t->v.n - ((unsigned) b & mask_bits[e]);
b >>= e;
k -= e;
/* do the copy */
do_copy: do {
n -= (e =
(e =
gunzip_wsize - ((d &= gunzip_wsize - 1) > w ? d : w)) > n ? n : e);
/* copy to new buffer to prevent possible overwrite */
if (w - d >= e) { /* (this test assumes unsigned comparison) */
memcpy(gunzip_window + w, gunzip_window + d, e);
w += e;
d += e;
} else {
/* do it slow to avoid memcpy() overlap */
/* !NOMEMCPY */
do {
gunzip_window[w++] = gunzip_window[d++];
} while (--e);
}
if (w == gunzip_wsize) {
gunzip_outbuf_count = (w);
if (n) resumeCopy = 1;
else resumeCopy = 0;
//flush_gunzip_window();
w = 0;
return 1;
}
} while (n);
resumeCopy = 0;
}
}
/* restore the globals from the locals */
gunzip_outbuf_count = w; /* restore global gunzip_window pointer */
gunzip_bb = b; /* restore global bit buffer */
gunzip_bk = k;
/* normally just after call to inflate_codes, but save code by putting it here */
/* free the decoding tables, return */
huft_free(tl);
huft_free(td);
/* done */
return 0;
}
static int inflate_stored(int my_n, int my_b_stored, int my_k_stored, int setup)
{
static int n, b_stored, k_stored, w;
if (setup) {
n = my_n;
b_stored = my_b_stored;
k_stored = my_k_stored;
w = gunzip_outbuf_count; /* initialize gunzip_window position */
return 0; // Don't do anything first time
}
/* read and output the compressed data */
while (n--) {
b_stored = fill_bitbuffer(b_stored, &k_stored, 8);
gunzip_window[w++] = (unsigned char) b_stored;
if (w == (unsigned int) gunzip_wsize) {
gunzip_outbuf_count = (w);
//flush_gunzip_window();
w = 0;
b_stored >>= 8;
k_stored -= 8;
return 1; // We have a block
}
b_stored >>= 8;
k_stored -= 8;
}
/* restore the globals from the locals */
gunzip_outbuf_count = w; /* restore global gunzip_window pointer */
gunzip_bb = b_stored; /* restore global bit buffer */
gunzip_bk = k_stored;
return 0; // Finished
}
/*
* decompress an inflated block
* e: last block flag
*
* GLOBAL VARIABLES: bb, kk,
*/
// Return values: -1 = inflate_stored, -2 = inflate_codes
static int inflate_block(int *e)
{
unsigned t; /* block type */
register unsigned int b; /* bit buffer */
unsigned int k; /* number of bits in bit buffer */
/* make local bit buffer */
b = gunzip_bb;
k = gunzip_bk;
/* read in last block bit */
b = fill_bitbuffer(b, &k, 1);
*e = (int) b & 1;
b >>= 1;
k -= 1;
/* read in block type */
b = fill_bitbuffer(b, &k, 2);
t = (unsigned) b & 3;
b >>= 2;
k -= 2;
/* restore the global bit buffer */
gunzip_bb = b;
gunzip_bk = k;
/* inflate that block type */
switch (t) {
case 0: /* Inflate stored */
{
unsigned int n; /* number of bytes in block */
unsigned int b_stored; /* bit buffer */
unsigned int k_stored; /* number of bits in bit buffer */
/* make local copies of globals */
b_stored = gunzip_bb; /* initialize bit buffer */
k_stored = gunzip_bk;
/* go to byte boundary */
n = k_stored & 7;
b_stored >>= n;
k_stored -= n;
/* get the length and its complement */
b_stored = fill_bitbuffer(b_stored, &k_stored, 16);
n = ((unsigned) b_stored & 0xffff);
b_stored >>= 16;
k_stored -= 16;
b_stored = fill_bitbuffer(b_stored, &k_stored, 16);
if (n != (unsigned) ((~b_stored) & 0xffff)) {
return 1; /* error in compressed data */
}
b_stored >>= 16;
k_stored -= 16;
inflate_stored(n, b_stored, k_stored, 1); // Setup inflate_stored
return -1;
}
case 1: /* Inflate fixed
* decompress an inflated type 1 (fixed Huffman codes) block. We should
* either replace this with a custom decoder, or at least precompute the
* Huffman tables.
*/
{
int i; /* temporary variable */
huft_t *tl; /* literal/length code table */
huft_t *td; /* distance code table */
unsigned int bl; /* lookup bits for tl */
unsigned int bd; /* lookup bits for td */
unsigned int l[288]; /* length list for huft_build */
/* set up literal table */
for (i = 0; i < 144; i++) {
l[i] = 8;
}
for (; i < 256; i++) {
l[i] = 9;
}
for (; i < 280; i++) {
l[i] = 7;
}
for (; i < 288; i++) { /* make a complete, but wrong code set */
l[i] = 8;
}
bl = 7;
if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0) {
return i;
}
/* set up distance table */
for (i = 0; i < 30; i++) { /* make an incomplete code set */
l[i] = 5;
}
bd = 5;
if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1) {
huft_free(tl);
return i;
}
/* decompress until an end-of-block code */
inflate_codes(tl, td, bl, bd, 1); // Setup inflate_codes
/* huft_free code moved into inflate_codes */
return -2;
}
case 2: /* Inflate dynamic */
{
const int dbits = 6; /* bits in base distance lookup table */
const int lbits = 9; /* bits in base literal/length lookup table */
huft_t *tl; /* literal/length code table */
huft_t *td; /* distance code table */
unsigned int i; /* temporary variables */
unsigned int j;
unsigned int l; /* last length */
unsigned int m; /* mask for bit lengths table */
unsigned int n; /* number of lengths to get */
unsigned int bl; /* lookup bits for tl */
unsigned int bd; /* lookup bits for td */
unsigned int nb; /* number of bit length codes */
unsigned int nl; /* number of literal/length codes */
unsigned int nd; /* number of distance codes */
unsigned int ll[286 + 30]; /* literal/length and distance code lengths */
unsigned int b_dynamic; /* bit buffer */
unsigned int k_dynamic; /* number of bits in bit buffer */
/* make local bit buffer */
b_dynamic = gunzip_bb;
k_dynamic = gunzip_bk;
/* read in table lengths */
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 5);
nl = 257 + ((unsigned int) b_dynamic & 0x1f); /* number of literal/length codes */
b_dynamic >>= 5;
k_dynamic -= 5;
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 5);
nd = 1 + ((unsigned int) b_dynamic & 0x1f); /* number of distance codes */
b_dynamic >>= 5;
k_dynamic -= 5;
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 4);
nb = 4 + ((unsigned int) b_dynamic & 0xf); /* number of bit length codes */
b_dynamic >>= 4;
k_dynamic -= 4;
if (nl > 286 || nd > 30) {
return 1; /* bad lengths */
}
/* read in bit-length-code lengths */
for (j = 0; j < nb; j++) {
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 3);
ll[border[j]] = (unsigned int) b_dynamic & 7;
b_dynamic >>= 3;
k_dynamic -= 3;
}
for (; j < 19; j++) {
ll[border[j]] = 0;
}
/* build decoding table for trees--single level, 7 bit lookup */
bl = 7;
i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl);
if (i != 0) {
if (i == 1) {
huft_free(tl);
}
return i; /* incomplete code set */
}
/* read in literal and distance code lengths */
n = nl + nd;
m = mask_bits[bl];
i = l = 0;
while ((unsigned int) i < n) {
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, (unsigned int)bl);
j = (td = tl + ((unsigned int) b_dynamic & m))->b;
b_dynamic >>= j;
k_dynamic -= j;
j = td->v.n;
if (j < 16) { /* length of code in bits (0..15) */
ll[i++] = l = j; /* save last length in l */
} else if (j == 16) { /* repeat last length 3 to 6 times */
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 2);
j = 3 + ((unsigned int) b_dynamic & 3);
b_dynamic >>= 2;
k_dynamic -= 2;
if ((unsigned int) i + j > n) {
return 1;
}
while (j--) {
ll[i++] = l;
}
} else if (j == 17) { /* 3 to 10 zero length codes */
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 3);
j = 3 + ((unsigned int) b_dynamic & 7);
b_dynamic >>= 3;
k_dynamic -= 3;
if ((unsigned int) i + j > n) {
return 1;
}
while (j--) {
ll[i++] = 0;
}
l = 0;
} else { /* j == 18: 11 to 138 zero length codes */
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 7);
j = 11 + ((unsigned int) b_dynamic & 0x7f);
b_dynamic >>= 7;
k_dynamic -= 7;
if ((unsigned int) i + j > n) {
return 1;
}
while (j--) {
ll[i++] = 0;
}
l = 0;
}
}
/* free decoding table for trees */
huft_free(tl);
/* restore the global bit buffer */
gunzip_bb = b_dynamic;
gunzip_bk = k_dynamic;
/* build the decoding tables for literal/length and distance codes */
bl = lbits;
if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0) {
if (i == 1) {
error_msg_and_die("Incomplete literal tree");
huft_free(tl);
}
return i; /* incomplete code set */
}
bd = dbits;
if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0) {
if (i == 1) {
error_msg_and_die("incomplete distance tree");
huft_free(td);
}
huft_free(tl);
return i; /* incomplete code set */
}
/* decompress until an end-of-block code */
inflate_codes(tl, td, bl, bd, 1); // Setup inflate_codes
/* huft_free code moved into inflate_codes */
return -2;
}
default:
/* bad block type */
error_msg_and_die("bad block type %d\n", t);
}
}
static void calculate_gunzip_crc(void)
{
int n;
for (n = 0; n < gunzip_outbuf_count; n++) {
gunzip_crc = gunzip_crc_table[((int) gunzip_crc ^ (gunzip_window[n])) & 0xff] ^ (gunzip_crc >> 8);
}
gunzip_bytes_out += gunzip_outbuf_count;
}
static int inflate_get_next_window(void)
{
static int needAnotherBlock = 1;
static int method = -1; // Method == -1 for stored, -2 for codes
static int e = 0;
gunzip_outbuf_count = 0;
while(1) {
int ret;
if (needAnotherBlock) {
if(e) {
calculate_gunzip_crc();
return 0;
} // Last block
method = inflate_block(&e);
needAnotherBlock = 0;
}
switch (method) {
case -1: ret = inflate_stored(0,0,0,0);
break;
case -2: ret = inflate_codes(0,0,0,0,0);
break;
default: error_msg_and_die("inflate error %d", method);
}
if (ret == 1) {
calculate_gunzip_crc();
return 1; // More data left
} else needAnotherBlock = 1; // End of that block
}
/* Doesnt get here */
}
/*
* User functions
*
* read_gz, GZ_gzReadOpen, GZ_gzReadClose, inflate
*/
extern ssize_t read_gz(int fd, void *buf, size_t count)
{
static int morebytes = 0, finished = 0;
if (morebytes) {
int bytesRead = morebytes > count ? count : morebytes;
memcpy(buf, gunzip_window + (gunzip_outbuf_count - morebytes), bytesRead);
morebytes -= bytesRead;
return bytesRead;
} else if (finished) {
return 0;
} else if (count >= 0x8000) { // We can decompress direcly to the buffer, 32k at a time
// Could decompress to larger buffer, but it must be a power of 2, and calculating that is probably more expensive than the benefit
unsigned char *old_gunzip_window = gunzip_window; // Save old window
gunzip_window = buf;
if (inflate_get_next_window() == 0) finished = 1;
gunzip_window = old_gunzip_window; // Restore old window
return gunzip_outbuf_count;
} else { // Oh well, need to split up the gunzip_window
int bytesRead;
if (inflate_get_next_window() == 0) finished = 1;
morebytes = gunzip_outbuf_count;
bytesRead = morebytes > count ? count : morebytes;
memcpy(buf, gunzip_window, bytesRead);
morebytes -= bytesRead;
return bytesRead;
}
}
extern void GZ_gzReadOpen(int fd, void *unused, int nUnused)
{
typedef void (*sig_type) (int);
/* Allocate all global buffers (for DYN_ALLOC option) */
gunzip_window = xmalloc(gunzip_wsize);
gunzip_outbuf_count = 0;
gunzip_bytes_out = 0;
gunzip_src_fd = fd;
/* Input buffer */
bytebuffer = xmalloc(BYTEBUFFER_MAX);
/* initialize gunzip_window, bit buffer */
gunzip_bk = 0;
gunzip_bb = 0;
/* Create the crc table */
make_gunzip_crc_table();
}
extern void GZ_gzReadClose(void)
{
/* Cleanup */
free(gunzip_window);
free(gunzip_crc_table);
/* Store unused bytes in a global buffer so calling applets can access it */
if (gunzip_bk >= 8) {
/* Undo too much lookahead. The next read will be byte aligned
* so we can discard unused bits in the last meaningful byte. */
bytebuffer_offset--;
bytebuffer[bytebuffer_offset] = gunzip_bb & 0xff;
gunzip_bb >>= 8;
gunzip_bk -= 8;
}
}
/*extern int inflate(int in, int out) // Useful for testing read_gz
{
char buf[8192];
ssize_t nread, nwrote;
GZ_gzReadOpen(in, 0, 0);
while(1) { // Robbed from copyfd.c
nread = read_gz(in, buf, sizeof(buf));
if (nread == 0) break; // no data to write
else if (nread == -1) {
perror_msg("read");
return -1;
}
nwrote = full_write(out, buf, nread);
if (nwrote == -1) {
perror_msg("write");
return -1;
}
}
GZ_gzReadClose();
return 0;
}*/
extern int inflate(int in, int out)
{
ssize_t nwrote;
GZ_gzReadOpen(in, 0, 0);
while(1) {
int ret = inflate_get_next_window();
nwrote = full_write(out, gunzip_window, gunzip_outbuf_count);
if (nwrote == -1) {
perror_msg("write");
return -1;
}
if (ret == 0) break;
}
GZ_gzReadClose();
return 0;
}
extern void check_trailer_gzip(int src_fd)
{
unsigned int stored_crc = 0;
unsigned char count;
/* top up the input buffer with the rest of the trailer */
count = bytebuffer_size - bytebuffer_offset;
if (count < 8) {
xread_all(src_fd, &bytebuffer[bytebuffer_size], 8 - count);
bytebuffer_size += 8 - count;
}
for (count = 0; count != 4; count++) {
stored_crc |= (bytebuffer[bytebuffer_offset] << (count * 8));
bytebuffer_offset++;
}
/* Validate decompression - crc */
if (stored_crc != (gunzip_crc ^ 0xffffffffL)) {
error_msg_and_die("crc error");
}
/* Validate decompression - size */
if (gunzip_bytes_out !=
(bytebuffer[bytebuffer_offset] | (bytebuffer[bytebuffer_offset+1] << 8) |
(bytebuffer[bytebuffer_offset+2] << 16) | (bytebuffer[bytebuffer_offset+3] << 24))) {
error_msg_and_die("Incorrect length, but crc is correct");
}
}