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6572ef6e1e
busybox/archival/libarchive/decompress_gunzip.c
Denys Vlasenko 6572ef6e1e gzip: code shrink 
huft_build() still has way too many params

function                                             old     new   delta
lit                                                    -      94     +94
dist                                                   -      94     +94
huft_build                                          1058    1054      -4
inflate_block                                       1281    1254     -27
cpdext                                                30       -     -30
cplext                                                31       -     -31
cpdist                                                60       -     -60
cplens                                                62       -     -62
------------------------------------------------------------------------------
(add/remove: 2/4 grow/shrink: 0/2 up/down: 188/-214)          Total: -26 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-10-19 18:53:19 +02:00

1282 lines
36 KiB
C
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/* 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 <andersen@codepoet.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
*
* read_gz interface + associated hacking by Laurence Anderson
*
* Fixed huft_build() so decoding end-of-block code does not grab more bits
* than necessary (this is required by unzip applet), added inflate_cleanup()
* to free leaked bytebuffer memory (used in unzip.c), and some minor style
* guide cleanups by Ed Clark
*
* 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 file algorithm.doc for the compression algorithms and file formats.
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
#include "bb_archive.h"
typedef struct huft_t {
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_t *t; /* pointer to next level of table */
} v;
} huft_t;
enum {
/* gunzip_window size--must be a power of two, and
* at least 32K for zip's deflate method */
GUNZIP_WSIZE = 0x8000,
/* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
BMAX = 16, /* maximum bit length of any code (16 for explode) */
N_MAX = 288, /* maximum number of codes in any set */
};
/* This is somewhat complex-looking arrangement, but it allows
* to place decompressor state either in bss or in
* malloc'ed space simply by changing #defines below.
* Sizes on i386:
* text data bss dec hex
* 5256 0 108 5364 14f4 - bss
* 4915 0 0 4915 1333 - malloc
*/
#define STATE_IN_BSS 0
#define STATE_IN_MALLOC 1
typedef struct state_t {
off_t gunzip_bytes_out; /* number of output bytes */
uint32_t gunzip_crc;
int gunzip_src_fd;
unsigned gunzip_outbuf_count; /* bytes in output buffer */
unsigned char *gunzip_window;
uint32_t *gunzip_crc_table;
/* bitbuffer */
unsigned gunzip_bb; /* bit buffer */
unsigned char gunzip_bk; /* bits in bit buffer */
/* input (compressed) data */
unsigned char *bytebuffer; /* buffer itself */
off_t to_read; /* compressed bytes to read (unzip only, -1 for gunzip) */
// unsigned bytebuffer_max; /* buffer size */
unsigned bytebuffer_offset; /* buffer position */
unsigned bytebuffer_size; /* how much data is there (size <= max) */
/* private data of inflate_codes() */
unsigned inflate_codes_ml; /* masks for bl and bd bits */
unsigned inflate_codes_md; /* masks for bl and bd bits */
unsigned inflate_codes_bb; /* bit buffer */
unsigned inflate_codes_k; /* number of bits in bit buffer */
unsigned inflate_codes_w; /* current gunzip_window position */
huft_t *inflate_codes_tl;
huft_t *inflate_codes_td;
unsigned inflate_codes_bl;
unsigned inflate_codes_bd;
unsigned inflate_codes_nn; /* length and index for copy */
unsigned inflate_codes_dd;
smallint resume_copy;
/* private data of inflate_get_next_window() */
smallint method; /* method == -1 for stored, -2 for codes */
smallint need_another_block;
smallint end_reached;
/* private data of inflate_stored() */
unsigned inflate_stored_n;
unsigned inflate_stored_b;
unsigned inflate_stored_k;
unsigned inflate_stored_w;
const char *error_msg;
jmp_buf error_jmp;
} state_t;
#define gunzip_bytes_out (S()gunzip_bytes_out )
#define gunzip_crc (S()gunzip_crc )
#define gunzip_src_fd (S()gunzip_src_fd )
#define gunzip_outbuf_count (S()gunzip_outbuf_count)
#define gunzip_window (S()gunzip_window )
#define gunzip_crc_table (S()gunzip_crc_table )
#define gunzip_bb (S()gunzip_bb )
#define gunzip_bk (S()gunzip_bk )
#define to_read (S()to_read )
// #define bytebuffer_max (S()bytebuffer_max )
// Both gunzip and unzip can use constant buffer size now (16k):
#define bytebuffer_max 0x4000
#define bytebuffer (S()bytebuffer )
#define bytebuffer_offset (S()bytebuffer_offset )
#define bytebuffer_size (S()bytebuffer_size )
#define inflate_codes_ml (S()inflate_codes_ml )
#define inflate_codes_md (S()inflate_codes_md )
#define inflate_codes_bb (S()inflate_codes_bb )
#define inflate_codes_k (S()inflate_codes_k )
#define inflate_codes_w (S()inflate_codes_w )
#define inflate_codes_tl (S()inflate_codes_tl )
#define inflate_codes_td (S()inflate_codes_td )
#define inflate_codes_bl (S()inflate_codes_bl )
#define inflate_codes_bd (S()inflate_codes_bd )
#define inflate_codes_nn (S()inflate_codes_nn )
#define inflate_codes_dd (S()inflate_codes_dd )
#define resume_copy (S()resume_copy )
#define method (S()method )
#define need_another_block (S()need_another_block )
#define end_reached (S()end_reached )
#define inflate_stored_n (S()inflate_stored_n )
#define inflate_stored_b (S()inflate_stored_b )
#define inflate_stored_k (S()inflate_stored_k )
#define inflate_stored_w (S()inflate_stored_w )
#define error_msg (S()error_msg )
#define error_jmp (S()error_jmp )
/* This is a generic part */
#if STATE_IN_BSS /* Use global data segment */
#define DECLARE_STATE /*nothing*/
#define ALLOC_STATE /*nothing*/
#define DEALLOC_STATE ((void)0)
#define S() state.
#define PASS_STATE /*nothing*/
#define PASS_STATE_ONLY /*nothing*/
#define STATE_PARAM /*nothing*/
#define STATE_PARAM_ONLY void
static state_t state;
#endif
#if STATE_IN_MALLOC /* Use malloc space */
#define DECLARE_STATE state_t *state
#define ALLOC_STATE (state = xzalloc(sizeof(*state)))
#define DEALLOC_STATE free(state)
#define S() state->
#define PASS_STATE state,
#define PASS_STATE_ONLY state
#define STATE_PARAM state_t *state,
#define STATE_PARAM_ONLY state_t *state
#endif
static const uint16_t mask_bits[] ALIGN2 = {
0x0000, 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
};
/* Put lengths/offsets and extra bits in a struct of arrays
* to make calls to huft_build() have one fewer parameter.
*/
struct cp_ext {
uint16_t cp[31];
uint8_t ext[31];
};
/* Copy lengths and extra bits for literal codes 257..285 */
/* note: see note #13 above about the 258 in this list. */
static const struct cp_ext lit = {
/*257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 */
/*0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 */
{ 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 },
{ 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 and extra bits for distance codes 0..29 */
static const struct cp_ext dist = {
/*0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 */
{ 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 },
{ 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 uint8_t border[] ALIGN1 = {
16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
};
/*
* 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 void huft_free(huft_t *p)
{
huft_t *q;
/* Go through linked list, freeing from the malloced (t[-1]) address. */
while (p) {
q = (--p)->v.t;
free(p);
p = q;
}
}
static void huft_free_all(STATE_PARAM_ONLY)
{
huft_free(inflate_codes_tl);
huft_free(inflate_codes_td);
inflate_codes_tl = NULL;
inflate_codes_td = NULL;
}
static void abort_unzip(STATE_PARAM_ONLY) NORETURN;
static void abort_unzip(STATE_PARAM_ONLY)
{
huft_free_all(PASS_STATE_ONLY);
longjmp(error_jmp, 1);
}
static unsigned fill_bitbuffer(STATE_PARAM unsigned bitbuffer, unsigned *current, const unsigned required)
{
while (*current < required) {
if (bytebuffer_offset >= bytebuffer_size) {
unsigned sz = bytebuffer_max - 4;
if (to_read >= 0 && to_read < sz) /* unzip only */
sz = to_read;
/* Leave the first 4 bytes empty so we can always unwind the bitbuffer
* to the front of the bytebuffer */
bytebuffer_size = safe_read(gunzip_src_fd, &bytebuffer[4], sz);
if ((int)bytebuffer_size < 1) {
error_msg = "unexpected end of file";
abort_unzip(PASS_STATE_ONLY);
}
if (to_read >= 0) /* unzip only */
to_read -= bytebuffer_size;
bytebuffer_size += 4;
bytebuffer_offset = 4;
}
bitbuffer |= ((unsigned) bytebuffer[bytebuffer_offset]) << *current;
bytebuffer_offset++;
*current += 8;
}
return bitbuffer;
}
/* Given a list of code lengths and a maximum table size, make a set of
* tables to decode that set of codes.
*
* 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
* m: maximum lookup bits, returns actual
* result: starting table
*/
static huft_t* huft_build(const unsigned *b, const unsigned n,
const unsigned s, const struct cp_ext *cp_ext,
unsigned *m)
{
unsigned a; /* counter for codes of length k */
unsigned c[BMAX + 1]; /* bit length count table */
unsigned eob_len; /* length of end-of-block code (value 256) */
unsigned f; /* i repeats in table every f entries */
int g; /* maximum code length */
int htl; /* table level */
unsigned i; /* counter, current code */
unsigned j; /* counter */
int k; /* number of bits in current code */
const unsigned *p; /* pointer into c[], b[], or v[] */
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 + 1]; /* values in order of bit length. last v[] is never used */
int ws[BMAX + 1]; /* bits decoded stack */
int w; /* bits decoded */
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 */
huft_t *result;
huft_t **t;
/* Length of EOB code, if any */
eob_len = n > 256 ? b[256] : BMAX;
/* Generate counts for each bit length */
memset(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 */
q = xzalloc(3 * sizeof(*q));
//q[0].v.t = NULL;
q[1].e = 99; /* invalid code marker */
q[1].b = 1;
q[2].e = 99; /* invalid code marker */
q[2].b = 1;
*m = 1;
return q + 1;
}
/* Find minimum and maximum length, bound *m by those */
for (j = 1; (j <= BMAX) && (c[j] == 0); j++)
continue;
k = j; /* minimum code length */
for (i = BMAX; (c[i] == 0) && i; i--)
continue;
g = i; /* maximum code length */
*m = (*m < j) ? j : ((*m > i) ? i : *m);
/* Adjust last length count to fill out codes, if needed */
for (y = 1 << j; j < i; j++, y <<= 1) {
y -= c[j];
if (y < 0)
return NULL; /* bad input: more codes than bits */
}
y -= c[i];
if (y < 0)
return NULL;
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 */
j += *p++;
*xp++ = j;
}
/* Make a table of values in order of bit lengths.
* To detect bad input, unused v[i]'s are set to invalid value UINT_MAX.
* In particular, last v[i] is never filled and must not be accessed.
*/
memset(v, 0xff, sizeof(v));
p = b;
i = 0;
do {
j = *p++;
if (j != 0) {
v[x[j]++] = i;
}
} while (++i < n);
/* Generate the Huffman codes and for each, make the table entries */
result = NULL;
t = &result;
x[0] = i = 0; /* first Huffman code is zero */
p = v; /* grab values in bit order */
htl = -1; /* no tables yet--level -1 */
w = ws[0] = 0; /* bits decoded */
u[0] = NULL; /* just to keep compilers happy */
q = 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 > ws[htl + 1]) {
w = ws[++htl];
/* compute minimum size table less than or equal to *m bits */
z = g - w;
z = z > *m ? *m : z; /* upper limit on table size */
j = k - w;
f = 1 << j;
if (f > 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 */
f <<= 1;
if (f <= *++xp) {
break; /* enough codes to use up j bits */
}
f -= *xp; /* else deduct codes from patterns */
}
}
j = (w + j > eob_len && w < eob_len) ? eob_len - w : j; /* make EOB code end at table */
z = 1 << j; /* table entries for j-bit table */
ws[htl+1] = w + j; /* set bits decoded in stack */
/* allocate and link in new table */
q = xzalloc((z + 1) * sizeof(huft_t));
*t = q + 1; /* link to list for huft_free() */
t = &(q->v.t);
u[htl] = ++q; /* table starts after link */
/* connect to last table, if there is one */
if (htl) {
x[htl] = i; /* save pattern for backing up */
r.b = (unsigned char) (w - ws[htl - 1]); /* 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 & ((1 << w) - 1)) >> ws[htl - 1];
u[htl - 1][j] = r; /* connect to last table */
}
}
/* set up table entry in r */
r.b = (unsigned char) (k - w);
if (/*p >= v + n || -- redundant, caught by the second check: */
*p == UINT_MAX /* do we access uninited v[i]? (see memset(v))*/
) {
r.e = 99; /* out of values--invalid code */
} else if (*p < s) {
r.e = (unsigned char) (*p < 256 ? 16 : 15); /* 256 is EOB code */
r.v.n = (unsigned short) (*p++); /* simple code is just the value */
} else {
r.e = (unsigned char) cp_ext->ext[*p - s]; /* non-simple--look up in lists */
r.v.n = cp_ext->cp[*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[htl]) {
w = ws[--htl];
}
}
}
/* return actual size of base table */
*m = ws[1];
if (y != 0 && g != 1) /* we were given an incomplete table */
return NULL;
return result;
}
/*
* 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[]
*/
/* called once from inflate_block */
/* map formerly local static variables to globals */
#define ml inflate_codes_ml
#define md inflate_codes_md
#define bb inflate_codes_bb
#define k inflate_codes_k
#define w inflate_codes_w
#define tl inflate_codes_tl
#define td inflate_codes_td
#define bl inflate_codes_bl
#define bd inflate_codes_bd
#define nn inflate_codes_nn
#define dd inflate_codes_dd
static void inflate_codes_setup(STATE_PARAM unsigned my_bl, unsigned my_bd)
{
bl = my_bl;
bd = my_bd;
/* make local copies of globals */
bb = 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];
}
/* called once from inflate_get_next_window */
static NOINLINE int inflate_codes(STATE_PARAM_ONLY)
{
unsigned e; /* table entry flag/number of extra bits */
huft_t *t; /* pointer to table entry */
if (resume_copy)
goto do_copy;
while (1) { /* do until end of block */
bb = fill_bitbuffer(PASS_STATE bb, &k, bl);
t = tl + ((unsigned) bb & ml);
e = t->e;
if (e > 16)
do {
if (e == 99) {
abort_unzip(PASS_STATE_ONLY);
}
bb >>= t->b;
k -= t->b;
e -= 16;
bb = fill_bitbuffer(PASS_STATE bb, &k, e);
t = t->v.t + ((unsigned) bb & mask_bits[e]);
e = t->e;
} while (e > 16);
bb >>= 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 */
bb = fill_bitbuffer(PASS_STATE bb, &k, e);
nn = t->v.n + ((unsigned) bb & mask_bits[e]);
bb >>= e;
k -= e;
/* decode distance of block to copy */
bb = fill_bitbuffer(PASS_STATE bb, &k, bd);
t = td + ((unsigned) bb & md);
e = t->e;
if (e > 16)
do {
if (e == 99) {
abort_unzip(PASS_STATE_ONLY);
}
bb >>= t->b;
k -= t->b;
e -= 16;
bb = fill_bitbuffer(PASS_STATE bb, &k, e);
t = t->v.t + ((unsigned) bb & mask_bits[e]);
e = t->e;
} while (e > 16);
bb >>= t->b;
k -= t->b;
bb = fill_bitbuffer(PASS_STATE bb, &k, e);
dd = w - t->v.n - ((unsigned) bb & mask_bits[e]);
bb >>= e;
k -= e;
/* do the copy */
do_copy:
do {
/* Was: nn -= (e = (e = GUNZIP_WSIZE - ((dd &= GUNZIP_WSIZE - 1) > w ? dd : w)) > nn ? nn : e); */
/* Who wrote THAT?? rewritten as: */
unsigned delta;
dd &= GUNZIP_WSIZE - 1;
e = GUNZIP_WSIZE - (dd > w ? dd : w);
delta = w > dd ? w - dd : dd - w;
if (e > nn) e = nn;
nn -= e;
/* copy to new buffer to prevent possible overwrite */
if (delta >= e) {
memcpy(gunzip_window + w, gunzip_window + dd, e);
w += e;
dd += e;
} else {
/* do it slow to avoid memcpy() overlap */
/* !NOMEMCPY */
do {
gunzip_window[w++] = gunzip_window[dd++];
} while (--e);
}
if (w == GUNZIP_WSIZE) {
gunzip_outbuf_count = w;
resume_copy = (nn != 0);
//flush_gunzip_window();
w = 0;
return 1;
}
} while (nn);
resume_copy = 0;
}
}
/* restore the globals from the locals */
gunzip_outbuf_count = w; /* restore global gunzip_window pointer */
gunzip_bb = bb; /* 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 (tl and td), return */
huft_free_all(PASS_STATE_ONLY);
/* done */
return 0;
}
#undef ml
#undef md
#undef bb
#undef k
#undef w
#undef tl
#undef td
#undef bl
#undef bd
#undef nn
#undef dd
/* called once from inflate_block */
static void inflate_stored_setup(STATE_PARAM int my_n, int my_b, int my_k)
{
inflate_stored_n = my_n;
inflate_stored_b = my_b;
inflate_stored_k = my_k;
/* initialize gunzip_window position */
inflate_stored_w = gunzip_outbuf_count;
}
/* called once from inflate_get_next_window */
static int inflate_stored(STATE_PARAM_ONLY)
{
/* read and output the compressed data */
while (inflate_stored_n--) {
inflate_stored_b = fill_bitbuffer(PASS_STATE inflate_stored_b, &inflate_stored_k, 8);
gunzip_window[inflate_stored_w++] = (unsigned char) inflate_stored_b;
if (inflate_stored_w == GUNZIP_WSIZE) {
gunzip_outbuf_count = inflate_stored_w;
//flush_gunzip_window();
inflate_stored_w = 0;
inflate_stored_b >>= 8;
inflate_stored_k -= 8;
return 1; /* We have a block */
}
inflate_stored_b >>= 8;
inflate_stored_k -= 8;
}
/* restore the globals from the locals */
gunzip_outbuf_count = inflate_stored_w; /* restore global gunzip_window pointer */
gunzip_bb = inflate_stored_b; /* restore global bit buffer */
gunzip_bk = inflate_stored_k;
return 0; /* Finished */
}
/*
* decompress an inflated block
* e: last block flag
*
* GLOBAL VARIABLES: bb, kk,
*/
/* Return values: -1 = inflate_stored, -2 = inflate_codes */
/* One callsite in inflate_get_next_window */
static int inflate_block(STATE_PARAM smallint *e)
{
unsigned ll[286 + 30]; /* literal/length and distance code lengths */
unsigned t; /* block type */
unsigned b; /* bit buffer */
unsigned 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(PASS_STATE b, &k, 1);
*e = b & 1;
b >>= 1;
k -= 1;
/* read in block type */
b = fill_bitbuffer(PASS_STATE b, &k, 2);
t = (unsigned) b & 3;
b >>= 2;
k -= 2;
/* restore the global bit buffer */
gunzip_bb = b;
gunzip_bk = k;
/* Do we see block type 1 often? Yes!
* TODO: fix performance problem (see below) */
//bb_error_msg("blktype %d", t);
/* inflate that block type */
switch (t) {
case 0: /* Inflate stored */
{
unsigned n; /* number of bytes in block */
unsigned b_stored; /* bit buffer */
unsigned 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(PASS_STATE b_stored, &k_stored, 16);
n = ((unsigned) b_stored & 0xffff);
b_stored >>= 16;
k_stored -= 16;
b_stored = fill_bitbuffer(PASS_STATE b_stored, &k_stored, 16);
if (n != (unsigned) ((~b_stored) & 0xffff)) {
abort_unzip(PASS_STATE_ONLY); /* error in compressed data */
}
b_stored >>= 16;
k_stored -= 16;
inflate_stored_setup(PASS_STATE n, b_stored, k_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. TODO */
{
int i; /* temporary variable */
unsigned bl; /* lookup bits for tl */
unsigned bd; /* lookup bits for td */
/* gcc 4.2.1 is too dumb to reuse stackspace. Moved up... */
//unsigned ll[288]; /* length list for huft_build */
/* set up literal table */
for (i = 0; i < 144; i++)
ll[i] = 8;
for (; i < 256; i++)
ll[i] = 9;
for (; i < 280; i++)
ll[i] = 7;
for (; i < 288; i++) /* make a complete, but wrong code set */
ll[i] = 8;
bl = 7;
inflate_codes_tl = huft_build(ll, 288, 257, &lit, &bl);
/* huft_build() never returns error here - we use known data */
/* set up distance table */
for (i = 0; i < 30; i++) /* make an incomplete code set */
ll[i] = 5;
bd = 5;
inflate_codes_td = huft_build(ll, 30, 0, &dist, &bd);
/* set up data for inflate_codes() */
inflate_codes_setup(PASS_STATE bl, bd);
/* huft_free code moved into inflate_codes */
return -2;
}
case 2: /* Inflate dynamic */
{
enum { dbits = 6 }; /* bits in base distance lookup table */
enum { lbits = 9 }; /* bits in base literal/length lookup table */
huft_t *td; /* distance code table */
unsigned i; /* temporary variables */
unsigned j;
unsigned l; /* last length */
unsigned m; /* mask for bit lengths table */
unsigned n; /* number of lengths to get */
unsigned bl; /* lookup bits for tl */
unsigned bd; /* lookup bits for td */
unsigned nb; /* number of bit length codes */
unsigned nl; /* number of literal/length codes */
unsigned nd; /* number of distance codes */
//unsigned ll[286 + 30];/* literal/length and distance code lengths */
unsigned b_dynamic; /* bit buffer */
unsigned 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(PASS_STATE b_dynamic, &k_dynamic, 5);
nl = 257 + ((unsigned) b_dynamic & 0x1f); /* number of literal/length codes */
b_dynamic >>= 5;
k_dynamic -= 5;
b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 5);
nd = 1 + ((unsigned) b_dynamic & 0x1f); /* number of distance codes */
b_dynamic >>= 5;
k_dynamic -= 5;
b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 4);
nb = 4 + ((unsigned) b_dynamic & 0xf); /* number of bit length codes */
b_dynamic >>= 4;
k_dynamic -= 4;
if (nl > 286 || nd > 30) {
abort_unzip(PASS_STATE_ONLY); /* bad lengths */
}
/* read in bit-length-code lengths */
for (j = 0; j < nb; j++) {
b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 3);
ll[border[j]] = (unsigned) 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;
inflate_codes_tl = huft_build(ll, 19, 19, NULL, &bl);
if (!inflate_codes_tl) {
abort_unzip(PASS_STATE_ONLY); /* incomplete code set */
}
/* read in literal and distance code lengths */
n = nl + nd;
m = mask_bits[bl];
i = l = 0;
while ((unsigned) i < n) {
b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, (unsigned)bl);
td = inflate_codes_tl + ((unsigned) b_dynamic & m);
j = td->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(PASS_STATE b_dynamic, &k_dynamic, 2);
j = 3 + ((unsigned) b_dynamic & 3);
b_dynamic >>= 2;
k_dynamic -= 2;
if ((unsigned) i + j > n) {
abort_unzip(PASS_STATE_ONLY); //return 1;
}
while (j--) {
ll[i++] = l;
}
} else if (j == 17) { /* 3 to 10 zero length codes */
b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 3);
j = 3 + ((unsigned) b_dynamic & 7);
b_dynamic >>= 3;
k_dynamic -= 3;
if ((unsigned) i + j > n) {
abort_unzip(PASS_STATE_ONLY); //return 1;
}
while (j--) {
ll[i++] = 0;
}
l = 0;
} else { /* j == 18: 11 to 138 zero length codes */
b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 7);
j = 11 + ((unsigned) b_dynamic & 0x7f);
b_dynamic >>= 7;
k_dynamic -= 7;
if ((unsigned) i + j > n) {
abort_unzip(PASS_STATE_ONLY); //return 1;
}
while (j--) {
ll[i++] = 0;
}
l = 0;
}
}
/* free decoding table for trees */
huft_free(inflate_codes_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;
inflate_codes_tl = huft_build(ll, nl, 257, &lit, &bl);
if (!inflate_codes_tl) {
abort_unzip(PASS_STATE_ONLY);
}
bd = dbits;
inflate_codes_td = huft_build(ll + nl, nd, 0, &dist, &bd);
if (!inflate_codes_td) {
abort_unzip(PASS_STATE_ONLY);
}
/* set up data for inflate_codes() */
inflate_codes_setup(PASS_STATE bl, bd);
/* huft_free code moved into inflate_codes */
return -2;
}
default:
abort_unzip(PASS_STATE_ONLY);
}
}
/* Two callsites, both in inflate_get_next_window */
static void calculate_gunzip_crc(STATE_PARAM_ONLY)
{
gunzip_crc = crc32_block_endian0(gunzip_crc, gunzip_window, gunzip_outbuf_count, gunzip_crc_table);
gunzip_bytes_out += gunzip_outbuf_count;
}
/* One callsite in inflate_unzip_internal */
static int inflate_get_next_window(STATE_PARAM_ONLY)
{
gunzip_outbuf_count = 0;
while (1) {
int ret;
if (need_another_block) {
if (end_reached) {
calculate_gunzip_crc(PASS_STATE_ONLY);
end_reached = 0;
/* NB: need_another_block is still set */
return 0; /* Last block */
}
method = inflate_block(PASS_STATE &end_reached);
need_another_block = 0;
}
switch (method) {
case -1:
ret = inflate_stored(PASS_STATE_ONLY);
break;
case -2:
ret = inflate_codes(PASS_STATE_ONLY);
break;
default: /* cannot happen */
abort_unzip(PASS_STATE_ONLY);
}
if (ret == 1) {
calculate_gunzip_crc(PASS_STATE_ONLY);
return 1; /* more data left */
}
need_another_block = 1; /* end of that block */
}
/* Doesnt get here */
}
/* Called from unpack_gz_stream() and inflate_unzip() */
static IF_DESKTOP(long long) int
inflate_unzip_internal(STATE_PARAM transformer_state_t *xstate)
{
IF_DESKTOP(long long) int n = 0;
ssize_t nwrote;
/* Allocate all global buffers (for DYN_ALLOC option) */
gunzip_window = xmalloc(GUNZIP_WSIZE);
gunzip_outbuf_count = 0;
gunzip_bytes_out = 0;
gunzip_src_fd = xstate->src_fd;
/* (re) initialize state */
method = -1;
need_another_block = 1;
resume_copy = 0;
gunzip_bk = 0;
gunzip_bb = 0;
/* Create the crc table */
gunzip_crc_table = crc32_new_table_le();
gunzip_crc = ~0;
error_msg = "corrupted data";
if (setjmp(error_jmp)) {
/* Error from deep inside zip machinery */
bb_simple_error_msg(error_msg);
n = -1;
goto ret;
}
while (1) {
int r = inflate_get_next_window(PASS_STATE_ONLY);
nwrote = transformer_write(xstate, gunzip_window, gunzip_outbuf_count);
if (nwrote == (ssize_t)-1) {
n = -1;
goto ret;
}
IF_DESKTOP(n += nwrote;)
if (r == 0) break;
}
/* 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;
}
ret:
/* Cleanup */
free(gunzip_window);
free(gunzip_crc_table);
return n;
}
/* External entry points */
/* For unzip */
IF_DESKTOP(long long) int FAST_FUNC
inflate_unzip(transformer_state_t *xstate)
{
IF_DESKTOP(long long) int n;
DECLARE_STATE;
ALLOC_STATE;
to_read = xstate->bytes_in;
// bytebuffer_max = 0x8000;
bytebuffer_offset = 4;
bytebuffer = xmalloc(bytebuffer_max);
n = inflate_unzip_internal(PASS_STATE xstate);
free(bytebuffer);
xstate->crc32 = gunzip_crc;
xstate->bytes_out = gunzip_bytes_out;
DEALLOC_STATE;
return n;
}
/* For gunzip */
/* helpers first */
/* Top up the input buffer with at least n bytes. */
static int top_up(STATE_PARAM unsigned n)
{
int count = bytebuffer_size - bytebuffer_offset;
if (count < (int)n) {
memmove(bytebuffer, &bytebuffer[bytebuffer_offset], count);
bytebuffer_offset = 0;
bytebuffer_size = full_read(gunzip_src_fd, &bytebuffer[count], bytebuffer_max - count);
if ((int)bytebuffer_size < 0) {
bb_simple_error_msg(bb_msg_read_error);
return 0;
}
bytebuffer_size += count;
if (bytebuffer_size < n)
return 0;
}
return 1;
}
static uint16_t buffer_read_le_u16(STATE_PARAM_ONLY)
{
uint16_t res;
#if BB_LITTLE_ENDIAN
move_from_unaligned16(res, &bytebuffer[bytebuffer_offset]);
#else
res = bytebuffer[bytebuffer_offset];
res |= bytebuffer[bytebuffer_offset + 1] << 8;
#endif
bytebuffer_offset += 2;
return res;
}
static uint32_t buffer_read_le_u32(STATE_PARAM_ONLY)
{
uint32_t res;
#if BB_LITTLE_ENDIAN
move_from_unaligned32(res, &bytebuffer[bytebuffer_offset]);
#else
res = bytebuffer[bytebuffer_offset];
res |= bytebuffer[bytebuffer_offset + 1] << 8;
res |= bytebuffer[bytebuffer_offset + 2] << 16;
res |= bytebuffer[bytebuffer_offset + 3] << 24;
#endif
bytebuffer_offset += 4;
return res;
}
static int check_header_gzip(STATE_PARAM transformer_state_t *xstate)
{
union {
unsigned char raw[8];
struct {
uint8_t gz_method;
uint8_t flags;
uint32_t mtime;
uint8_t xtra_flags_UNUSED;
uint8_t os_flags_UNUSED;
} PACKED formatted;
} header;
BUILD_BUG_ON(sizeof(header) != 8);
/*
* Rewind bytebuffer. We use the beginning because the header has 8
* bytes, leaving enough for unwinding afterwards.
*/
bytebuffer_size -= bytebuffer_offset;
memmove(bytebuffer, &bytebuffer[bytebuffer_offset], bytebuffer_size);
bytebuffer_offset = 0;
if (!top_up(PASS_STATE 8))
return 0;
memcpy(header.raw, &bytebuffer[bytebuffer_offset], 8);
bytebuffer_offset += 8;
/* Check the compression method */
if (header.formatted.gz_method != 8) {
return 0;
}
if (header.formatted.flags & 0x04) {
/* bit 2 set: extra field present */
unsigned extra_short;
if (!top_up(PASS_STATE 2))
return 0;
extra_short = buffer_read_le_u16(PASS_STATE_ONLY);
if (!top_up(PASS_STATE extra_short))
return 0;
/* Ignore extra field */
bytebuffer_offset += extra_short;
}
/* Discard original name and file comment if any */
/* bit 3 set: original file name present */
/* bit 4 set: file comment present */
if (header.formatted.flags & 0x18) {
while (1) {
do {
if (!top_up(PASS_STATE 1))
return 0;
} while (bytebuffer[bytebuffer_offset++] != 0);
if ((header.formatted.flags & 0x18) != 0x18)
break;
header.formatted.flags &= ~0x18;
}
}
xstate->mtime = SWAP_LE32(header.formatted.mtime);
/* Read the header checksum */
if (header.formatted.flags & 0x02) {
if (!top_up(PASS_STATE 2))
return 0;
bytebuffer_offset += 2;
}
return 1;
}
IF_DESKTOP(long long) int FAST_FUNC
unpack_gz_stream(transformer_state_t *xstate)
{
uint32_t v32;
IF_DESKTOP(long long) int total, n;
DECLARE_STATE;
#if !ENABLE_FEATURE_SEAMLESS_Z
if (check_signature16(xstate, GZIP_MAGIC))
return -1;
#else
if (!xstate->signature_skipped) {
uint16_t magic2;
if (full_read(xstate->src_fd, &magic2, 2) != 2) {
bad_magic:
bb_simple_error_msg("invalid magic");
return -1;
}
if (magic2 == COMPRESS_MAGIC) {
xstate->signature_skipped = 2;
return unpack_Z_stream(xstate);
}
if (magic2 != GZIP_MAGIC)
goto bad_magic;
}
#endif
total = 0;
ALLOC_STATE;
to_read = -1;
// bytebuffer_max = 0x8000;
bytebuffer = xmalloc(bytebuffer_max);
gunzip_src_fd = xstate->src_fd;
again:
if (!check_header_gzip(PASS_STATE xstate)) {
bb_simple_error_msg("corrupted data");
total = -1;
goto ret;
}
n = inflate_unzip_internal(PASS_STATE xstate);
if (n < 0) {
total = -1;
goto ret;
}
total += n;
if (!top_up(PASS_STATE 8)) {
bb_simple_error_msg("corrupted data");
total = -1;
goto ret;
}
/* Validate decompression - crc */
v32 = buffer_read_le_u32(PASS_STATE_ONLY);
if ((~gunzip_crc) != v32) {
bb_simple_error_msg("crc error");
total = -1;
goto ret;
}
/* Validate decompression - size */
v32 = buffer_read_le_u32(PASS_STATE_ONLY);
if ((uint32_t)gunzip_bytes_out != v32) {
bb_simple_error_msg("incorrect length");
total = -1;
}
if (!top_up(PASS_STATE 2))
goto ret; /* EOF */
if (bytebuffer[bytebuffer_offset] == 0x1f
&& bytebuffer[bytebuffer_offset + 1] == 0x8b
) {
bytebuffer_offset += 2;
goto again;
}
/* GNU gzip says: */
/*bb_error_msg("decompression OK, trailing garbage ignored");*/
ret:
free(bytebuffer);
DEALLOC_STATE;
return total;
}
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