1 /* vi: set sw=4 ts=4: */
3 * gunzip implementation for busybox
5 * Based on GNU gzip v1.2.4 Copyright (C) 1992-1993 Jean-loup Gailly.
7 * Originally adjusted for busybox by Sven Rudolph <sr1@inf.tu-dresden.de>
8 * based on gzip sources
10 * Adjusted further by Erik Andersen <andersen@codepoet.org> to support
11 * files as well as stdin/stdout, and to generally behave itself wrt
12 * command line handling.
14 * General cleanup to better adhere to the style guide and make use of standard
15 * busybox functions by Glenn McGrath
17 * read_gz interface + associated hacking by Laurence Anderson
19 * Fixed huft_build() so decoding end-of-block code does not grab more bits
20 * than necessary (this is required by unzip applet), added inflate_cleanup()
21 * to free leaked bytebuffer memory (used in unzip.c), and some minor style
22 * guide cleanups by Ed Clark
24 * gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
25 * Copyright (C) 1992-1993 Jean-loup Gailly
26 * The unzip code was written and put in the public domain by Mark Adler.
27 * Portions of the lzw code are derived from the public domain 'compress'
28 * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
29 * Ken Turkowski, Dave Mack and Peter Jannesen.
31 * See the file algorithm.doc for the compression algorithms and file formats.
33 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
38 #include "bb_archive.h"
40 typedef struct huft_t {
41 unsigned char e; /* number of extra bits or operation */
42 unsigned char b; /* number of bits in this code or subcode */
44 unsigned short n; /* literal, length base, or distance base */
45 struct huft_t *t; /* pointer to next level of table */
50 /* gunzip_window size--must be a power of two, and
51 * at least 32K for zip's deflate method */
52 GUNZIP_WSIZE = 0x8000,
53 /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
54 BMAX = 16, /* maximum bit length of any code (16 for explode) */
55 N_MAX = 288, /* maximum number of codes in any set */
59 /* This is somewhat complex-looking arrangement, but it allows
60 * to place decompressor state either in bss or in
61 * malloc'ed space simply by changing #defines below.
63 * text data bss dec hex
64 * 5256 0 108 5364 14f4 - bss
65 * 4915 0 0 4915 1333 - malloc
67 #define STATE_IN_BSS 0
68 #define STATE_IN_MALLOC 1
71 typedef struct state_t {
72 off_t gunzip_bytes_out; /* number of output bytes */
76 unsigned gunzip_outbuf_count; /* bytes in output buffer */
78 unsigned char *gunzip_window;
80 uint32_t *gunzip_crc_table;
83 unsigned gunzip_bb; /* bit buffer */
84 unsigned char gunzip_bk; /* bits in bit buffer */
86 /* input (compressed) data */
87 unsigned char *bytebuffer; /* buffer itself */
88 off_t to_read; /* compressed bytes to read (unzip only, -1 for gunzip) */
89 // unsigned bytebuffer_max; /* buffer size */
90 unsigned bytebuffer_offset; /* buffer position */
91 unsigned bytebuffer_size; /* how much data is there (size <= max) */
93 /* private data of inflate_codes() */
94 unsigned inflate_codes_ml; /* masks for bl and bd bits */
95 unsigned inflate_codes_md; /* masks for bl and bd bits */
96 unsigned inflate_codes_bb; /* bit buffer */
97 unsigned inflate_codes_k; /* number of bits in bit buffer */
98 unsigned inflate_codes_w; /* current gunzip_window position */
99 huft_t *inflate_codes_tl;
100 huft_t *inflate_codes_td;
101 unsigned inflate_codes_bl;
102 unsigned inflate_codes_bd;
103 unsigned inflate_codes_nn; /* length and index for copy */
104 unsigned inflate_codes_dd;
106 smallint resume_copy;
108 /* private data of inflate_get_next_window() */
109 smallint method; /* method == -1 for stored, -2 for codes */
110 smallint need_another_block;
111 smallint end_reached;
113 /* private data of inflate_stored() */
114 unsigned inflate_stored_n;
115 unsigned inflate_stored_b;
116 unsigned inflate_stored_k;
117 unsigned inflate_stored_w;
119 const char *error_msg;
122 #define gunzip_bytes_out (S()gunzip_bytes_out )
123 #define gunzip_crc (S()gunzip_crc )
124 #define gunzip_src_fd (S()gunzip_src_fd )
125 #define gunzip_outbuf_count (S()gunzip_outbuf_count)
126 #define gunzip_window (S()gunzip_window )
127 #define gunzip_crc_table (S()gunzip_crc_table )
128 #define gunzip_bb (S()gunzip_bb )
129 #define gunzip_bk (S()gunzip_bk )
130 #define to_read (S()to_read )
131 // #define bytebuffer_max (S()bytebuffer_max )
132 // Both gunzip and unzip can use constant buffer size now (16k):
133 #define bytebuffer_max 0x4000
134 #define bytebuffer (S()bytebuffer )
135 #define bytebuffer_offset (S()bytebuffer_offset )
136 #define bytebuffer_size (S()bytebuffer_size )
137 #define inflate_codes_ml (S()inflate_codes_ml )
138 #define inflate_codes_md (S()inflate_codes_md )
139 #define inflate_codes_bb (S()inflate_codes_bb )
140 #define inflate_codes_k (S()inflate_codes_k )
141 #define inflate_codes_w (S()inflate_codes_w )
142 #define inflate_codes_tl (S()inflate_codes_tl )
143 #define inflate_codes_td (S()inflate_codes_td )
144 #define inflate_codes_bl (S()inflate_codes_bl )
145 #define inflate_codes_bd (S()inflate_codes_bd )
146 #define inflate_codes_nn (S()inflate_codes_nn )
147 #define inflate_codes_dd (S()inflate_codes_dd )
148 #define resume_copy (S()resume_copy )
149 #define method (S()method )
150 #define need_another_block (S()need_another_block )
151 #define end_reached (S()end_reached )
152 #define inflate_stored_n (S()inflate_stored_n )
153 #define inflate_stored_b (S()inflate_stored_b )
154 #define inflate_stored_k (S()inflate_stored_k )
155 #define inflate_stored_w (S()inflate_stored_w )
156 #define error_msg (S()error_msg )
157 #define error_jmp (S()error_jmp )
159 /* This is a generic part */
160 #if STATE_IN_BSS /* Use global data segment */
161 #define DECLARE_STATE /*nothing*/
162 #define ALLOC_STATE /*nothing*/
163 #define DEALLOC_STATE ((void)0)
165 #define PASS_STATE /*nothing*/
166 #define PASS_STATE_ONLY /*nothing*/
167 #define STATE_PARAM /*nothing*/
168 #define STATE_PARAM_ONLY void
169 static state_t state;
172 #if STATE_IN_MALLOC /* Use malloc space */
173 #define DECLARE_STATE state_t *state
174 #define ALLOC_STATE (state = xzalloc(sizeof(*state)))
175 #define DEALLOC_STATE free(state)
177 #define PASS_STATE state,
178 #define PASS_STATE_ONLY state
179 #define STATE_PARAM state_t *state,
180 #define STATE_PARAM_ONLY state_t *state
184 static const uint16_t mask_bits[] ALIGN2 = {
185 0x0000, 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
186 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
189 /* Copy lengths for literal codes 257..285 */
190 static const uint16_t cplens[] ALIGN2 = {
191 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
192 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
195 /* note: see note #13 above about the 258 in this list. */
196 /* Extra bits for literal codes 257..285 */
197 static const uint8_t cplext[] ALIGN1 = {
198 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,
200 }; /* 99 == invalid */
202 /* Copy offsets for distance codes 0..29 */
203 static const uint16_t cpdist[] ALIGN2 = {
204 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513,
205 769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577
208 /* Extra bits for distance codes */
209 static const uint8_t cpdext[] ALIGN1 = {
210 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10,
211 11, 11, 12, 12, 13, 13
214 /* Tables for deflate from PKZIP's appnote.txt. */
215 /* Order of the bit length code lengths */
216 static const uint8_t border[] ALIGN1 = {
217 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
222 * Free the malloc'ed tables built by huft_build(), which makes a linked
223 * list of the tables it made, with the links in a dummy first entry of
227 static void huft_free(huft_t *p)
231 /* Go through linked list, freeing from the malloced (t[-1]) address. */
239 static void huft_free_all(STATE_PARAM_ONLY)
241 huft_free(inflate_codes_tl);
242 huft_free(inflate_codes_td);
243 inflate_codes_tl = NULL;
244 inflate_codes_td = NULL;
247 static void abort_unzip(STATE_PARAM_ONLY) NORETURN;
248 static void abort_unzip(STATE_PARAM_ONLY)
250 huft_free_all(PASS_STATE_ONLY);
251 longjmp(error_jmp, 1);
254 static unsigned fill_bitbuffer(STATE_PARAM unsigned bitbuffer, unsigned *current, const unsigned required)
256 while (*current < required) {
257 if (bytebuffer_offset >= bytebuffer_size) {
258 unsigned sz = bytebuffer_max - 4;
259 if (to_read >= 0 && to_read < sz) /* unzip only */
261 /* Leave the first 4 bytes empty so we can always unwind the bitbuffer
262 * to the front of the bytebuffer */
263 bytebuffer_size = safe_read(gunzip_src_fd, &bytebuffer[4], sz);
264 if ((int)bytebuffer_size < 1) {
265 error_msg = "unexpected end of file";
266 abort_unzip(PASS_STATE_ONLY);
268 if (to_read >= 0) /* unzip only */
269 to_read -= bytebuffer_size;
270 bytebuffer_size += 4;
271 bytebuffer_offset = 4;
273 bitbuffer |= ((unsigned) bytebuffer[bytebuffer_offset]) << *current;
281 /* Given a list of code lengths and a maximum table size, make a set of
282 * tables to decode that set of codes. Return zero on success, one if
283 * the given code set is incomplete (the tables are still built in this
284 * case), two if the input is invalid (all zero length codes or an
285 * oversubscribed set of lengths) - in this case stores NULL in *t.
287 * b: code lengths in bits (all assumed <= BMAX)
288 * n: number of codes (assumed <= N_MAX)
289 * s: number of simple-valued codes (0..s-1)
290 * d: list of base values for non-simple codes
291 * e: list of extra bits for non-simple codes
292 * t: result: starting table
293 * m: maximum lookup bits, returns actual
295 static int huft_build(const unsigned *b, const unsigned n,
296 const unsigned s, const unsigned short *d,
297 const unsigned char *e, huft_t **t, unsigned *m)
299 unsigned a; /* counter for codes of length k */
300 unsigned c[BMAX + 1]; /* bit length count table */
301 unsigned eob_len; /* length of end-of-block code (value 256) */
302 unsigned f; /* i repeats in table every f entries */
303 int g; /* maximum code length */
304 int htl; /* table level */
305 unsigned i; /* counter, current code */
306 unsigned j; /* counter */
307 int k; /* number of bits in current code */
308 const unsigned *p; /* pointer into c[], b[], or v[] */
309 huft_t *q; /* points to current table */
310 huft_t r; /* table entry for structure assignment */
311 huft_t *u[BMAX]; /* table stack */
312 unsigned v[N_MAX + 1]; /* values in order of bit length. last v[] is never used */
313 int ws[BMAX + 1]; /* bits decoded stack */
314 int w; /* bits decoded */
315 unsigned x[BMAX + 1]; /* bit offsets, then code stack */
316 unsigned *xp; /* pointer into x */
317 int y; /* number of dummy codes added */
318 unsigned z; /* number of entries in current table */
320 /* Length of EOB code, if any */
321 eob_len = n > 256 ? b[256] : BMAX;
325 /* Generate counts for each bit length */
326 memset(c, 0, sizeof(c));
330 c[*p]++; /* assume all entries <= BMAX */
331 p++; /* can't combine with above line (Solaris bug) */
333 if (c[0] == n) { /* null input - all zero length codes */
338 /* Find minimum and maximum length, bound *m by those */
339 for (j = 1; (j <= BMAX) && (c[j] == 0); j++)
341 k = j; /* minimum code length */
342 for (i = BMAX; (c[i] == 0) && i; i--)
344 g = i; /* maximum code length */
345 *m = (*m < j) ? j : ((*m > i) ? i : *m);
347 /* Adjust last length count to fill out codes, if needed */
348 for (y = 1 << j; j < i; j++, y <<= 1) {
351 return 2; /* bad input: more codes than bits */
358 /* Generate starting offsets into the value table for each length */
362 while (--i) { /* note that i == g from above */
367 /* Make a table of values in order of bit lengths.
368 * To detect bad input, unused v[i]'s are set to invalid value UINT_MAX.
369 * In particular, last v[i] is never filled and must not be accessed.
371 memset(v, 0xff, sizeof(v));
381 /* Generate the Huffman codes and for each, make the table entries */
382 x[0] = i = 0; /* first Huffman code is zero */
383 p = v; /* grab values in bit order */
384 htl = -1; /* no tables yet--level -1 */
385 w = ws[0] = 0; /* bits decoded */
386 u[0] = NULL; /* just to keep compilers happy */
387 q = NULL; /* ditto */
390 /* go through the bit lengths (k already is bits in shortest code) */
391 for (; k <= g; k++) {
394 /* here i is the Huffman code of length k bits for value *p */
395 /* make tables up to required level */
396 while (k > ws[htl + 1]) {
399 /* compute minimum size table less than or equal to *m bits */
401 z = z > *m ? *m : z; /* upper limit on table size */
404 if (f > a + 1) { /* try a k-w bit table */
405 /* too few codes for k-w bit table */
406 f -= a + 1; /* deduct codes from patterns left */
408 while (++j < z) { /* try smaller tables up to z bits */
411 break; /* enough codes to use up j bits */
413 f -= *xp; /* else deduct codes from patterns */
416 j = (w + j > eob_len && w < eob_len) ? eob_len - w : j; /* make EOB code end at table */
417 z = 1 << j; /* table entries for j-bit table */
418 ws[htl+1] = w + j; /* set bits decoded in stack */
420 /* allocate and link in new table */
421 q = xzalloc((z + 1) * sizeof(huft_t));
422 *t = q + 1; /* link to list for huft_free() */
424 u[htl] = ++q; /* table starts after link */
426 /* connect to last table, if there is one */
428 x[htl] = i; /* save pattern for backing up */
429 r.b = (unsigned char) (w - ws[htl - 1]); /* bits to dump before this table */
430 r.e = (unsigned char) (16 + j); /* bits in this table */
431 r.v.t = q; /* pointer to this table */
432 j = (i & ((1 << w) - 1)) >> ws[htl - 1];
433 u[htl - 1][j] = r; /* connect to last table */
437 /* set up table entry in r */
438 r.b = (unsigned char) (k - w);
439 if (/*p >= v + n || -- redundant, caught by the second check: */
440 *p == UINT_MAX /* do we access uninited v[i]? (see memset(v))*/
442 r.e = 99; /* out of values--invalid code */
444 r.e = (unsigned char) (*p < 256 ? 16 : 15); /* 256 is EOB code */
445 r.v.n = (unsigned short) (*p++); /* simple code is just the value */
447 r.e = (unsigned char) e[*p - s]; /* non-simple--look up in lists */
451 /* fill code-like entries with r */
453 for (j = i >> w; j < z; j += f) {
457 /* backwards increment the k-bit code i */
458 for (j = 1 << (k - 1); i & j; j >>= 1) {
463 /* backup over finished tables */
464 while ((i & ((1 << w) - 1)) != x[htl]) {
470 /* return actual size of base table */
473 /* Return 1 if we were given an incomplete table */
474 return y != 0 && g != 1;
479 * inflate (decompress) the codes in a deflated (compressed) block.
480 * Return an error code or zero if it all goes ok.
482 * tl, td: literal/length and distance decoder tables
483 * bl, bd: number of bits decoded by tl[] and td[]
485 /* called once from inflate_block */
487 /* map formerly local static variables to globals */
488 #define ml inflate_codes_ml
489 #define md inflate_codes_md
490 #define bb inflate_codes_bb
491 #define k inflate_codes_k
492 #define w inflate_codes_w
493 #define tl inflate_codes_tl
494 #define td inflate_codes_td
495 #define bl inflate_codes_bl
496 #define bd inflate_codes_bd
497 #define nn inflate_codes_nn
498 #define dd inflate_codes_dd
499 static void inflate_codes_setup(STATE_PARAM unsigned my_bl, unsigned my_bd)
503 /* make local copies of globals */
504 bb = gunzip_bb; /* initialize bit buffer */
506 w = gunzip_outbuf_count; /* initialize gunzip_window position */
507 /* inflate the coded data */
508 ml = mask_bits[bl]; /* precompute masks for speed */
511 /* called once from inflate_get_next_window */
512 static NOINLINE int inflate_codes(STATE_PARAM_ONLY)
514 unsigned e; /* table entry flag/number of extra bits */
515 huft_t *t; /* pointer to table entry */
520 while (1) { /* do until end of block */
521 bb = fill_bitbuffer(PASS_STATE bb, &k, bl);
522 t = tl + ((unsigned) bb & ml);
527 abort_unzip(PASS_STATE_ONLY);
532 bb = fill_bitbuffer(PASS_STATE bb, &k, e);
533 t = t->v.t + ((unsigned) bb & mask_bits[e]);
538 if (e == 16) { /* then it's a literal */
539 gunzip_window[w++] = (unsigned char) t->v.n;
540 if (w == GUNZIP_WSIZE) {
541 gunzip_outbuf_count = w;
542 //flush_gunzip_window();
544 return 1; // We have a block to read
546 } else { /* it's an EOB or a length */
547 /* exit if end of block */
552 /* get length of block to copy */
553 bb = fill_bitbuffer(PASS_STATE bb, &k, e);
554 nn = t->v.n + ((unsigned) bb & mask_bits[e]);
558 /* decode distance of block to copy */
559 bb = fill_bitbuffer(PASS_STATE bb, &k, bd);
560 t = td + ((unsigned) bb & md);
565 abort_unzip(PASS_STATE_ONLY);
570 bb = fill_bitbuffer(PASS_STATE bb, &k, e);
571 t = t->v.t + ((unsigned) bb & mask_bits[e]);
576 bb = fill_bitbuffer(PASS_STATE bb, &k, e);
577 dd = w - t->v.n - ((unsigned) bb & mask_bits[e]);
584 /* Was: nn -= (e = (e = GUNZIP_WSIZE - ((dd &= GUNZIP_WSIZE - 1) > w ? dd : w)) > nn ? nn : e); */
585 /* Who wrote THAT?? rewritten as: */
588 dd &= GUNZIP_WSIZE - 1;
589 e = GUNZIP_WSIZE - (dd > w ? dd : w);
590 delta = w > dd ? w - dd : dd - w;
594 /* copy to new buffer to prevent possible overwrite */
596 memcpy(gunzip_window + w, gunzip_window + dd, e);
600 /* do it slow to avoid memcpy() overlap */
603 gunzip_window[w++] = gunzip_window[dd++];
606 if (w == GUNZIP_WSIZE) {
607 gunzip_outbuf_count = w;
608 resume_copy = (nn != 0);
609 //flush_gunzip_window();
618 /* restore the globals from the locals */
619 gunzip_outbuf_count = w; /* restore global gunzip_window pointer */
620 gunzip_bb = bb; /* restore global bit buffer */
623 /* normally just after call to inflate_codes, but save code by putting it here */
624 /* free the decoding tables (tl and td), return */
625 huft_free_all(PASS_STATE_ONLY);
643 /* called once from inflate_block */
644 static void inflate_stored_setup(STATE_PARAM int my_n, int my_b, int my_k)
646 inflate_stored_n = my_n;
647 inflate_stored_b = my_b;
648 inflate_stored_k = my_k;
649 /* initialize gunzip_window position */
650 inflate_stored_w = gunzip_outbuf_count;
652 /* called once from inflate_get_next_window */
653 static int inflate_stored(STATE_PARAM_ONLY)
655 /* read and output the compressed data */
656 while (inflate_stored_n--) {
657 inflate_stored_b = fill_bitbuffer(PASS_STATE inflate_stored_b, &inflate_stored_k, 8);
658 gunzip_window[inflate_stored_w++] = (unsigned char) inflate_stored_b;
659 if (inflate_stored_w == GUNZIP_WSIZE) {
660 gunzip_outbuf_count = inflate_stored_w;
661 //flush_gunzip_window();
662 inflate_stored_w = 0;
663 inflate_stored_b >>= 8;
664 inflate_stored_k -= 8;
665 return 1; /* We have a block */
667 inflate_stored_b >>= 8;
668 inflate_stored_k -= 8;
671 /* restore the globals from the locals */
672 gunzip_outbuf_count = inflate_stored_w; /* restore global gunzip_window pointer */
673 gunzip_bb = inflate_stored_b; /* restore global bit buffer */
674 gunzip_bk = inflate_stored_k;
675 return 0; /* Finished */
680 * decompress an inflated block
683 * GLOBAL VARIABLES: bb, kk,
685 /* Return values: -1 = inflate_stored, -2 = inflate_codes */
686 /* One callsite in inflate_get_next_window */
687 static int inflate_block(STATE_PARAM smallint *e)
689 unsigned ll[286 + 30]; /* literal/length and distance code lengths */
690 unsigned t; /* block type */
691 unsigned b; /* bit buffer */
692 unsigned k; /* number of bits in bit buffer */
694 /* make local bit buffer */
699 /* read in last block bit */
700 b = fill_bitbuffer(PASS_STATE b, &k, 1);
705 /* read in block type */
706 b = fill_bitbuffer(PASS_STATE b, &k, 2);
707 t = (unsigned) b & 3;
711 /* restore the global bit buffer */
715 /* Do we see block type 1 often? Yes!
716 * TODO: fix performance problem (see below) */
717 //bb_error_msg("blktype %d", t);
719 /* inflate that block type */
721 case 0: /* Inflate stored */
723 unsigned n; /* number of bytes in block */
724 unsigned b_stored; /* bit buffer */
725 unsigned k_stored; /* number of bits in bit buffer */
727 /* make local copies of globals */
728 b_stored = gunzip_bb; /* initialize bit buffer */
729 k_stored = gunzip_bk;
731 /* go to byte boundary */
736 /* get the length and its complement */
737 b_stored = fill_bitbuffer(PASS_STATE b_stored, &k_stored, 16);
738 n = ((unsigned) b_stored & 0xffff);
742 b_stored = fill_bitbuffer(PASS_STATE b_stored, &k_stored, 16);
743 if (n != (unsigned) ((~b_stored) & 0xffff)) {
744 abort_unzip(PASS_STATE_ONLY); /* error in compressed data */
749 inflate_stored_setup(PASS_STATE n, b_stored, k_stored);
755 * decompress an inflated type 1 (fixed Huffman codes) block. We should
756 * either replace this with a custom decoder, or at least precompute the
757 * Huffman tables. TODO */
759 int i; /* temporary variable */
760 unsigned bl; /* lookup bits for tl */
761 unsigned bd; /* lookup bits for td */
762 /* gcc 4.2.1 is too dumb to reuse stackspace. Moved up... */
763 //unsigned ll[288]; /* length list for huft_build */
765 /* set up literal table */
766 for (i = 0; i < 144; i++)
772 for (; i < 288; i++) /* make a complete, but wrong code set */
775 huft_build(ll, 288, 257, cplens, cplext, &inflate_codes_tl, &bl);
776 /* huft_build() never return nonzero - we use known data */
778 /* set up distance table */
779 for (i = 0; i < 30; i++) /* make an incomplete code set */
782 huft_build(ll, 30, 0, cpdist, cpdext, &inflate_codes_td, &bd);
784 /* set up data for inflate_codes() */
785 inflate_codes_setup(PASS_STATE bl, bd);
787 /* huft_free code moved into inflate_codes */
791 case 2: /* Inflate dynamic */
793 enum { dbits = 6 }; /* bits in base distance lookup table */
794 enum { lbits = 9 }; /* bits in base literal/length lookup table */
796 huft_t *td; /* distance code table */
797 unsigned i; /* temporary variables */
799 unsigned l; /* last length */
800 unsigned m; /* mask for bit lengths table */
801 unsigned n; /* number of lengths to get */
802 unsigned bl; /* lookup bits for tl */
803 unsigned bd; /* lookup bits for td */
804 unsigned nb; /* number of bit length codes */
805 unsigned nl; /* number of literal/length codes */
806 unsigned nd; /* number of distance codes */
808 //unsigned ll[286 + 30];/* literal/length and distance code lengths */
809 unsigned b_dynamic; /* bit buffer */
810 unsigned k_dynamic; /* number of bits in bit buffer */
812 /* make local bit buffer */
813 b_dynamic = gunzip_bb;
814 k_dynamic = gunzip_bk;
816 /* read in table lengths */
817 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 5);
818 nl = 257 + ((unsigned) b_dynamic & 0x1f); /* number of literal/length codes */
822 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 5);
823 nd = 1 + ((unsigned) b_dynamic & 0x1f); /* number of distance codes */
827 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 4);
828 nb = 4 + ((unsigned) b_dynamic & 0xf); /* number of bit length codes */
832 if (nl > 286 || nd > 30) {
833 abort_unzip(PASS_STATE_ONLY); /* bad lengths */
836 /* read in bit-length-code lengths */
837 for (j = 0; j < nb; j++) {
838 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 3);
839 ll[border[j]] = (unsigned) b_dynamic & 7;
846 /* build decoding table for trees - single level, 7 bit lookup */
848 i = huft_build(ll, 19, 19, NULL, NULL, &inflate_codes_tl, &bl);
850 abort_unzip(PASS_STATE_ONLY); //return i; /* incomplete code set */
853 /* read in literal and distance code lengths */
857 while ((unsigned) i < n) {
858 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, (unsigned)bl);
859 td = inflate_codes_tl + ((unsigned) b_dynamic & m);
864 if (j < 16) { /* length of code in bits (0..15) */
865 ll[i++] = l = j; /* save last length in l */
866 } else if (j == 16) { /* repeat last length 3 to 6 times */
867 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 2);
868 j = 3 + ((unsigned) b_dynamic & 3);
871 if ((unsigned) i + j > n) {
872 abort_unzip(PASS_STATE_ONLY); //return 1;
877 } else if (j == 17) { /* 3 to 10 zero length codes */
878 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 3);
879 j = 3 + ((unsigned) b_dynamic & 7);
882 if ((unsigned) i + j > n) {
883 abort_unzip(PASS_STATE_ONLY); //return 1;
889 } else { /* j == 18: 11 to 138 zero length codes */
890 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 7);
891 j = 11 + ((unsigned) b_dynamic & 0x7f);
894 if ((unsigned) i + j > n) {
895 abort_unzip(PASS_STATE_ONLY); //return 1;
904 /* free decoding table for trees */
905 huft_free(inflate_codes_tl);
907 /* restore the global bit buffer */
908 gunzip_bb = b_dynamic;
909 gunzip_bk = k_dynamic;
911 /* build the decoding tables for literal/length and distance codes */
914 i = huft_build(ll, nl, 257, cplens, cplext, &inflate_codes_tl, &bl);
916 abort_unzip(PASS_STATE_ONLY);
919 i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &inflate_codes_td, &bd);
921 abort_unzip(PASS_STATE_ONLY);
924 /* set up data for inflate_codes() */
925 inflate_codes_setup(PASS_STATE bl, bd);
927 /* huft_free code moved into inflate_codes */
932 abort_unzip(PASS_STATE_ONLY);
936 /* Two callsites, both in inflate_get_next_window */
937 static void calculate_gunzip_crc(STATE_PARAM_ONLY)
939 gunzip_crc = crc32_block_endian0(gunzip_crc, gunzip_window, gunzip_outbuf_count, gunzip_crc_table);
940 gunzip_bytes_out += gunzip_outbuf_count;
943 /* One callsite in inflate_unzip_internal */
944 static int inflate_get_next_window(STATE_PARAM_ONLY)
946 gunzip_outbuf_count = 0;
951 if (need_another_block) {
953 calculate_gunzip_crc(PASS_STATE_ONLY);
955 /* NB: need_another_block is still set */
956 return 0; /* Last block */
958 method = inflate_block(PASS_STATE &end_reached);
959 need_another_block = 0;
964 ret = inflate_stored(PASS_STATE_ONLY);
967 ret = inflate_codes(PASS_STATE_ONLY);
969 default: /* cannot happen */
970 abort_unzip(PASS_STATE_ONLY);
974 calculate_gunzip_crc(PASS_STATE_ONLY);
975 return 1; /* more data left */
977 need_another_block = 1; /* end of that block */
979 /* Doesnt get here */
983 /* Called from unpack_gz_stream() and inflate_unzip() */
984 static IF_DESKTOP(long long) int
985 inflate_unzip_internal(STATE_PARAM transformer_state_t *xstate)
987 IF_DESKTOP(long long) int n = 0;
990 /* Allocate all global buffers (for DYN_ALLOC option) */
991 gunzip_window = xmalloc(GUNZIP_WSIZE);
992 gunzip_outbuf_count = 0;
993 gunzip_bytes_out = 0;
994 gunzip_src_fd = xstate->src_fd;
996 /* (re) initialize state */
998 need_another_block = 1;
1003 /* Create the crc table */
1004 gunzip_crc_table = crc32_filltable(NULL, 0);
1007 error_msg = "corrupted data";
1008 if (setjmp(error_jmp)) {
1009 /* Error from deep inside zip machinery */
1010 bb_error_msg(error_msg);
1016 int r = inflate_get_next_window(PASS_STATE_ONLY);
1017 nwrote = transformer_write(xstate, gunzip_window, gunzip_outbuf_count);
1018 if (nwrote == (ssize_t)-1) {
1022 IF_DESKTOP(n += nwrote;)
1026 /* Store unused bytes in a global buffer so calling applets can access it */
1027 if (gunzip_bk >= 8) {
1028 /* Undo too much lookahead. The next read will be byte aligned
1029 * so we can discard unused bits in the last meaningful byte. */
1030 bytebuffer_offset--;
1031 bytebuffer[bytebuffer_offset] = gunzip_bb & 0xff;
1037 free(gunzip_window);
1038 free(gunzip_crc_table);
1043 /* External entry points */
1047 IF_DESKTOP(long long) int FAST_FUNC
1048 inflate_unzip(transformer_state_t *xstate)
1050 IF_DESKTOP(long long) int n;
1055 to_read = xstate->bytes_in;
1056 // bytebuffer_max = 0x8000;
1057 bytebuffer_offset = 4;
1058 bytebuffer = xmalloc(bytebuffer_max);
1059 n = inflate_unzip_internal(PASS_STATE xstate);
1062 xstate->crc32 = gunzip_crc;
1063 xstate->bytes_out = gunzip_bytes_out;
1073 /* Top up the input buffer with at least n bytes. */
1074 static int top_up(STATE_PARAM unsigned n)
1076 int count = bytebuffer_size - bytebuffer_offset;
1078 if (count < (int)n) {
1079 memmove(bytebuffer, &bytebuffer[bytebuffer_offset], count);
1080 bytebuffer_offset = 0;
1081 bytebuffer_size = full_read(gunzip_src_fd, &bytebuffer[count], bytebuffer_max - count);
1082 if ((int)bytebuffer_size < 0) {
1083 bb_error_msg(bb_msg_read_error);
1086 bytebuffer_size += count;
1087 if (bytebuffer_size < n)
1093 static uint16_t buffer_read_le_u16(STATE_PARAM_ONLY)
1096 #if BB_LITTLE_ENDIAN
1097 move_from_unaligned16(res, &bytebuffer[bytebuffer_offset]);
1099 res = bytebuffer[bytebuffer_offset];
1100 res |= bytebuffer[bytebuffer_offset + 1] << 8;
1102 bytebuffer_offset += 2;
1106 static uint32_t buffer_read_le_u32(STATE_PARAM_ONLY)
1109 #if BB_LITTLE_ENDIAN
1110 move_from_unaligned32(res, &bytebuffer[bytebuffer_offset]);
1112 res = bytebuffer[bytebuffer_offset];
1113 res |= bytebuffer[bytebuffer_offset + 1] << 8;
1114 res |= bytebuffer[bytebuffer_offset + 2] << 16;
1115 res |= bytebuffer[bytebuffer_offset + 3] << 24;
1117 bytebuffer_offset += 4;
1121 static int check_header_gzip(STATE_PARAM transformer_state_t *xstate)
1124 unsigned char raw[8];
1129 uint8_t xtra_flags_UNUSED;
1130 uint8_t os_flags_UNUSED;
1134 BUILD_BUG_ON(sizeof(header) != 8);
1137 * Rewind bytebuffer. We use the beginning because the header has 8
1138 * bytes, leaving enough for unwinding afterwards.
1140 bytebuffer_size -= bytebuffer_offset;
1141 memmove(bytebuffer, &bytebuffer[bytebuffer_offset], bytebuffer_size);
1142 bytebuffer_offset = 0;
1144 if (!top_up(PASS_STATE 8))
1146 memcpy(header.raw, &bytebuffer[bytebuffer_offset], 8);
1147 bytebuffer_offset += 8;
1149 /* Check the compression method */
1150 if (header.formatted.gz_method != 8) {
1154 if (header.formatted.flags & 0x04) {
1155 /* bit 2 set: extra field present */
1156 unsigned extra_short;
1158 if (!top_up(PASS_STATE 2))
1160 extra_short = buffer_read_le_u16(PASS_STATE_ONLY);
1161 if (!top_up(PASS_STATE extra_short))
1163 /* Ignore extra field */
1164 bytebuffer_offset += extra_short;
1167 /* Discard original name and file comment if any */
1168 /* bit 3 set: original file name present */
1169 /* bit 4 set: file comment present */
1170 if (header.formatted.flags & 0x18) {
1173 if (!top_up(PASS_STATE 1))
1175 } while (bytebuffer[bytebuffer_offset++] != 0);
1176 if ((header.formatted.flags & 0x18) != 0x18)
1178 header.formatted.flags &= ~0x18;
1182 xstate->mtime = SWAP_LE32(header.formatted.mtime);
1184 /* Read the header checksum */
1185 if (header.formatted.flags & 0x02) {
1186 if (!top_up(PASS_STATE 2))
1188 bytebuffer_offset += 2;
1193 IF_DESKTOP(long long) int FAST_FUNC
1194 unpack_gz_stream(transformer_state_t *xstate)
1197 IF_DESKTOP(long long) int total, n;
1200 #if !ENABLE_FEATURE_SEAMLESS_Z
1201 if (check_signature16(xstate, GZIP_MAGIC))
1204 if (!xstate->signature_skipped) {
1207 if (full_read(xstate->src_fd, &magic2, 2) != 2) {
1209 bb_error_msg("invalid magic");
1212 if (magic2 == COMPRESS_MAGIC) {
1213 xstate->signature_skipped = 2;
1214 return unpack_Z_stream(xstate);
1216 if (magic2 != GZIP_MAGIC)
1225 // bytebuffer_max = 0x8000;
1226 bytebuffer = xmalloc(bytebuffer_max);
1227 gunzip_src_fd = xstate->src_fd;
1230 if (!check_header_gzip(PASS_STATE xstate)) {
1231 bb_error_msg("corrupted data");
1236 n = inflate_unzip_internal(PASS_STATE xstate);
1243 if (!top_up(PASS_STATE 8)) {
1244 bb_error_msg("corrupted data");
1249 /* Validate decompression - crc */
1250 v32 = buffer_read_le_u32(PASS_STATE_ONLY);
1251 if ((~gunzip_crc) != v32) {
1252 bb_error_msg("crc error");
1257 /* Validate decompression - size */
1258 v32 = buffer_read_le_u32(PASS_STATE_ONLY);
1259 if ((uint32_t)gunzip_bytes_out != v32) {
1260 bb_error_msg("incorrect length");
1264 if (!top_up(PASS_STATE 2))
1267 if (bytebuffer[bytebuffer_offset] == 0x1f
1268 && bytebuffer[bytebuffer_offset + 1] == 0x8b
1270 bytebuffer_offset += 2;
1273 /* GNU gzip says: */
1274 /*bb_error_msg("decompression OK, trailing garbage ignored");*/