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 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]; /* values in order of bit length */
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));
327 p = (unsigned *) b; /* cast allows us to reuse p for pointing to b */
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; (c[j] == 0) && (j <= BMAX); 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 */
377 /* Generate the Huffman codes and for each, make the table entries */
378 x[0] = i = 0; /* first Huffman code is zero */
379 p = v; /* grab values in bit order */
380 htl = -1; /* no tables yet--level -1 */
381 w = ws[0] = 0; /* bits decoded */
382 u[0] = NULL; /* just to keep compilers happy */
383 q = NULL; /* ditto */
386 /* go through the bit lengths (k already is bits in shortest code) */
387 for (; k <= g; k++) {
390 /* here i is the Huffman code of length k bits for value *p */
391 /* make tables up to required level */
392 while (k > ws[htl + 1]) {
395 /* compute minimum size table less than or equal to *m bits */
397 z = z > *m ? *m : z; /* upper limit on table size */
400 if (f > a + 1) { /* try a k-w bit table */
401 /* too few codes for k-w bit table */
402 f -= a + 1; /* deduct codes from patterns left */
404 while (++j < z) { /* try smaller tables up to z bits */
407 break; /* enough codes to use up j bits */
409 f -= *xp; /* else deduct codes from patterns */
412 j = (w + j > eob_len && w < eob_len) ? eob_len - w : j; /* make EOB code end at table */
413 z = 1 << j; /* table entries for j-bit table */
414 ws[htl+1] = w + j; /* set bits decoded in stack */
416 /* allocate and link in new table */
417 q = xzalloc((z + 1) * sizeof(huft_t));
418 *t = q + 1; /* link to list for huft_free() */
420 u[htl] = ++q; /* table starts after link */
422 /* connect to last table, if there is one */
424 x[htl] = i; /* save pattern for backing up */
425 r.b = (unsigned char) (w - ws[htl - 1]); /* bits to dump before this table */
426 r.e = (unsigned char) (16 + j); /* bits in this table */
427 r.v.t = q; /* pointer to this table */
428 j = (i & ((1 << w) - 1)) >> ws[htl - 1];
429 u[htl - 1][j] = r; /* connect to last table */
433 /* set up table entry in r */
434 r.b = (unsigned char) (k - w);
436 r.e = 99; /* out of values--invalid code */
438 r.e = (unsigned char) (*p < 256 ? 16 : 15); /* 256 is EOB code */
439 r.v.n = (unsigned short) (*p++); /* simple code is just the value */
441 r.e = (unsigned char) e[*p - s]; /* non-simple--look up in lists */
445 /* fill code-like entries with r */
447 for (j = i >> w; j < z; j += f) {
451 /* backwards increment the k-bit code i */
452 for (j = 1 << (k - 1); i & j; j >>= 1) {
457 /* backup over finished tables */
458 while ((i & ((1 << w) - 1)) != x[htl]) {
464 /* return actual size of base table */
467 /* Return 1 if we were given an incomplete table */
468 return y != 0 && g != 1;
473 * inflate (decompress) the codes in a deflated (compressed) block.
474 * Return an error code or zero if it all goes ok.
476 * tl, td: literal/length and distance decoder tables
477 * bl, bd: number of bits decoded by tl[] and td[]
479 /* called once from inflate_block */
481 /* map formerly local static variables to globals */
482 #define ml inflate_codes_ml
483 #define md inflate_codes_md
484 #define bb inflate_codes_bb
485 #define k inflate_codes_k
486 #define w inflate_codes_w
487 #define tl inflate_codes_tl
488 #define td inflate_codes_td
489 #define bl inflate_codes_bl
490 #define bd inflate_codes_bd
491 #define nn inflate_codes_nn
492 #define dd inflate_codes_dd
493 static void inflate_codes_setup(STATE_PARAM unsigned my_bl, unsigned my_bd)
497 /* make local copies of globals */
498 bb = gunzip_bb; /* initialize bit buffer */
500 w = gunzip_outbuf_count; /* initialize gunzip_window position */
501 /* inflate the coded data */
502 ml = mask_bits[bl]; /* precompute masks for speed */
505 /* called once from inflate_get_next_window */
506 static NOINLINE int inflate_codes(STATE_PARAM_ONLY)
508 unsigned e; /* table entry flag/number of extra bits */
509 huft_t *t; /* pointer to table entry */
514 while (1) { /* do until end of block */
515 bb = fill_bitbuffer(PASS_STATE bb, &k, bl);
516 t = tl + ((unsigned) bb & ml);
521 abort_unzip(PASS_STATE_ONLY);;
525 bb = fill_bitbuffer(PASS_STATE bb, &k, e);
526 t = t->v.t + ((unsigned) bb & mask_bits[e]);
531 if (e == 16) { /* then it's a literal */
532 gunzip_window[w++] = (unsigned char) t->v.n;
533 if (w == GUNZIP_WSIZE) {
534 gunzip_outbuf_count = w;
535 //flush_gunzip_window();
537 return 1; // We have a block to read
539 } else { /* it's an EOB or a length */
540 /* exit if end of block */
545 /* get length of block to copy */
546 bb = fill_bitbuffer(PASS_STATE bb, &k, e);
547 nn = t->v.n + ((unsigned) bb & mask_bits[e]);
551 /* decode distance of block to copy */
552 bb = fill_bitbuffer(PASS_STATE bb, &k, bd);
553 t = td + ((unsigned) bb & md);
558 abort_unzip(PASS_STATE_ONLY);
562 bb = fill_bitbuffer(PASS_STATE bb, &k, e);
563 t = t->v.t + ((unsigned) bb & mask_bits[e]);
568 bb = fill_bitbuffer(PASS_STATE bb, &k, e);
569 dd = w - t->v.n - ((unsigned) bb & mask_bits[e]);
576 /* Was: nn -= (e = (e = GUNZIP_WSIZE - ((dd &= GUNZIP_WSIZE - 1) > w ? dd : w)) > nn ? nn : e); */
577 /* Who wrote THAT?? rewritten as: */
580 dd &= GUNZIP_WSIZE - 1;
581 e = GUNZIP_WSIZE - (dd > w ? dd : w);
582 delta = w > dd ? w - dd : dd - w;
586 /* copy to new buffer to prevent possible overwrite */
588 memcpy(gunzip_window + w, gunzip_window + dd, e);
592 /* do it slow to avoid memcpy() overlap */
595 gunzip_window[w++] = gunzip_window[dd++];
598 if (w == GUNZIP_WSIZE) {
599 gunzip_outbuf_count = w;
600 resume_copy = (nn != 0);
601 //flush_gunzip_window();
610 /* restore the globals from the locals */
611 gunzip_outbuf_count = w; /* restore global gunzip_window pointer */
612 gunzip_bb = bb; /* restore global bit buffer */
615 /* normally just after call to inflate_codes, but save code by putting it here */
616 /* free the decoding tables (tl and td), return */
617 huft_free_all(PASS_STATE_ONLY);
635 /* called once from inflate_block */
636 static void inflate_stored_setup(STATE_PARAM int my_n, int my_b, int my_k)
638 inflate_stored_n = my_n;
639 inflate_stored_b = my_b;
640 inflate_stored_k = my_k;
641 /* initialize gunzip_window position */
642 inflate_stored_w = gunzip_outbuf_count;
644 /* called once from inflate_get_next_window */
645 static int inflate_stored(STATE_PARAM_ONLY)
647 /* read and output the compressed data */
648 while (inflate_stored_n--) {
649 inflate_stored_b = fill_bitbuffer(PASS_STATE inflate_stored_b, &inflate_stored_k, 8);
650 gunzip_window[inflate_stored_w++] = (unsigned char) inflate_stored_b;
651 if (inflate_stored_w == GUNZIP_WSIZE) {
652 gunzip_outbuf_count = inflate_stored_w;
653 //flush_gunzip_window();
654 inflate_stored_w = 0;
655 inflate_stored_b >>= 8;
656 inflate_stored_k -= 8;
657 return 1; /* We have a block */
659 inflate_stored_b >>= 8;
660 inflate_stored_k -= 8;
663 /* restore the globals from the locals */
664 gunzip_outbuf_count = inflate_stored_w; /* restore global gunzip_window pointer */
665 gunzip_bb = inflate_stored_b; /* restore global bit buffer */
666 gunzip_bk = inflate_stored_k;
667 return 0; /* Finished */
672 * decompress an inflated block
675 * GLOBAL VARIABLES: bb, kk,
677 /* Return values: -1 = inflate_stored, -2 = inflate_codes */
678 /* One callsite in inflate_get_next_window */
679 static int inflate_block(STATE_PARAM smallint *e)
681 unsigned ll[286 + 30]; /* literal/length and distance code lengths */
682 unsigned t; /* block type */
683 unsigned b; /* bit buffer */
684 unsigned k; /* number of bits in bit buffer */
686 /* make local bit buffer */
691 /* read in last block bit */
692 b = fill_bitbuffer(PASS_STATE b, &k, 1);
697 /* read in block type */
698 b = fill_bitbuffer(PASS_STATE b, &k, 2);
699 t = (unsigned) b & 3;
703 /* restore the global bit buffer */
707 /* Do we see block type 1 often? Yes!
708 * TODO: fix performance problem (see below) */
709 //bb_error_msg("blktype %d", t);
711 /* inflate that block type */
713 case 0: /* Inflate stored */
715 unsigned n; /* number of bytes in block */
716 unsigned b_stored; /* bit buffer */
717 unsigned k_stored; /* number of bits in bit buffer */
719 /* make local copies of globals */
720 b_stored = gunzip_bb; /* initialize bit buffer */
721 k_stored = gunzip_bk;
723 /* go to byte boundary */
728 /* get the length and its complement */
729 b_stored = fill_bitbuffer(PASS_STATE b_stored, &k_stored, 16);
730 n = ((unsigned) b_stored & 0xffff);
734 b_stored = fill_bitbuffer(PASS_STATE b_stored, &k_stored, 16);
735 if (n != (unsigned) ((~b_stored) & 0xffff)) {
736 abort_unzip(PASS_STATE_ONLY); /* error in compressed data */
741 inflate_stored_setup(PASS_STATE n, b_stored, k_stored);
747 * decompress an inflated type 1 (fixed Huffman codes) block. We should
748 * either replace this with a custom decoder, or at least precompute the
749 * Huffman tables. TODO */
751 int i; /* temporary variable */
752 unsigned bl; /* lookup bits for tl */
753 unsigned bd; /* lookup bits for td */
754 /* gcc 4.2.1 is too dumb to reuse stackspace. Moved up... */
755 //unsigned ll[288]; /* length list for huft_build */
757 /* set up literal table */
758 for (i = 0; i < 144; i++)
764 for (; i < 288; i++) /* make a complete, but wrong code set */
767 huft_build(ll, 288, 257, cplens, cplext, &inflate_codes_tl, &bl);
768 /* huft_build() never return nonzero - we use known data */
770 /* set up distance table */
771 for (i = 0; i < 30; i++) /* make an incomplete code set */
774 huft_build(ll, 30, 0, cpdist, cpdext, &inflate_codes_td, &bd);
776 /* set up data for inflate_codes() */
777 inflate_codes_setup(PASS_STATE bl, bd);
779 /* huft_free code moved into inflate_codes */
783 case 2: /* Inflate dynamic */
785 enum { dbits = 6 }; /* bits in base distance lookup table */
786 enum { lbits = 9 }; /* bits in base literal/length lookup table */
788 huft_t *td; /* distance code table */
789 unsigned i; /* temporary variables */
791 unsigned l; /* last length */
792 unsigned m; /* mask for bit lengths table */
793 unsigned n; /* number of lengths to get */
794 unsigned bl; /* lookup bits for tl */
795 unsigned bd; /* lookup bits for td */
796 unsigned nb; /* number of bit length codes */
797 unsigned nl; /* number of literal/length codes */
798 unsigned nd; /* number of distance codes */
800 //unsigned ll[286 + 30];/* literal/length and distance code lengths */
801 unsigned b_dynamic; /* bit buffer */
802 unsigned k_dynamic; /* number of bits in bit buffer */
804 /* make local bit buffer */
805 b_dynamic = gunzip_bb;
806 k_dynamic = gunzip_bk;
808 /* read in table lengths */
809 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 5);
810 nl = 257 + ((unsigned) b_dynamic & 0x1f); /* number of literal/length codes */
814 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 5);
815 nd = 1 + ((unsigned) b_dynamic & 0x1f); /* number of distance codes */
819 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 4);
820 nb = 4 + ((unsigned) b_dynamic & 0xf); /* number of bit length codes */
824 if (nl > 286 || nd > 30)
825 abort_unzip(PASS_STATE_ONLY); /* bad lengths */
827 /* read in bit-length-code lengths */
828 for (j = 0; j < nb; j++) {
829 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 3);
830 ll[border[j]] = (unsigned) b_dynamic & 7;
837 /* build decoding table for trees - single level, 7 bit lookup */
839 i = huft_build(ll, 19, 19, NULL, NULL, &inflate_codes_tl, &bl);
841 abort_unzip(PASS_STATE_ONLY); //return i; /* incomplete code set */
844 /* read in literal and distance code lengths */
848 while ((unsigned) i < n) {
849 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, (unsigned)bl);
850 td = inflate_codes_tl + ((unsigned) b_dynamic & m);
855 if (j < 16) { /* length of code in bits (0..15) */
856 ll[i++] = l = j; /* save last length in l */
857 } else if (j == 16) { /* repeat last length 3 to 6 times */
858 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 2);
859 j = 3 + ((unsigned) b_dynamic & 3);
862 if ((unsigned) i + j > n) {
863 abort_unzip(PASS_STATE_ONLY); //return 1;
868 } else if (j == 17) { /* 3 to 10 zero length codes */
869 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 3);
870 j = 3 + ((unsigned) b_dynamic & 7);
873 if ((unsigned) i + j > n) {
874 abort_unzip(PASS_STATE_ONLY); //return 1;
880 } else { /* j == 18: 11 to 138 zero length codes */
881 b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 7);
882 j = 11 + ((unsigned) b_dynamic & 0x7f);
885 if ((unsigned) i + j > n) {
886 abort_unzip(PASS_STATE_ONLY); //return 1;
895 /* free decoding table for trees */
896 huft_free(inflate_codes_tl);
898 /* restore the global bit buffer */
899 gunzip_bb = b_dynamic;
900 gunzip_bk = k_dynamic;
902 /* build the decoding tables for literal/length and distance codes */
905 i = huft_build(ll, nl, 257, cplens, cplext, &inflate_codes_tl, &bl);
907 abort_unzip(PASS_STATE_ONLY);
909 i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &inflate_codes_td, &bd);
911 abort_unzip(PASS_STATE_ONLY);
913 /* set up data for inflate_codes() */
914 inflate_codes_setup(PASS_STATE bl, bd);
916 /* huft_free code moved into inflate_codes */
921 abort_unzip(PASS_STATE_ONLY);
925 /* Two callsites, both in inflate_get_next_window */
926 static void calculate_gunzip_crc(STATE_PARAM_ONLY)
928 gunzip_crc = crc32_block_endian0(gunzip_crc, gunzip_window, gunzip_outbuf_count, gunzip_crc_table);
929 gunzip_bytes_out += gunzip_outbuf_count;
932 /* One callsite in inflate_unzip_internal */
933 static int inflate_get_next_window(STATE_PARAM_ONLY)
935 gunzip_outbuf_count = 0;
940 if (need_another_block) {
942 calculate_gunzip_crc(PASS_STATE_ONLY);
944 /* NB: need_another_block is still set */
945 return 0; /* Last block */
947 method = inflate_block(PASS_STATE &end_reached);
948 need_another_block = 0;
953 ret = inflate_stored(PASS_STATE_ONLY);
956 ret = inflate_codes(PASS_STATE_ONLY);
958 default: /* cannot happen */
959 abort_unzip(PASS_STATE_ONLY);
963 calculate_gunzip_crc(PASS_STATE_ONLY);
964 return 1; /* more data left */
966 need_another_block = 1; /* end of that block */
968 /* Doesnt get here */
972 /* Called from unpack_gz_stream() and inflate_unzip() */
973 static IF_DESKTOP(long long) int
974 inflate_unzip_internal(STATE_PARAM int in, int out)
976 IF_DESKTOP(long long) int n = 0;
979 /* Allocate all global buffers (for DYN_ALLOC option) */
980 gunzip_window = xmalloc(GUNZIP_WSIZE);
981 gunzip_outbuf_count = 0;
982 gunzip_bytes_out = 0;
985 /* (re) initialize state */
987 need_another_block = 1;
992 /* Create the crc table */
993 gunzip_crc_table = crc32_filltable(NULL, 0);
996 error_msg = "corrupted data";
997 if (setjmp(error_jmp)) {
998 /* Error from deep inside zip machinery */
1004 int r = inflate_get_next_window(PASS_STATE_ONLY);
1005 nwrote = full_write(out, gunzip_window, gunzip_outbuf_count);
1006 if (nwrote != (ssize_t)gunzip_outbuf_count) {
1007 bb_perror_msg("write");
1011 IF_DESKTOP(n += nwrote;)
1015 /* Store unused bytes in a global buffer so calling applets can access it */
1016 if (gunzip_bk >= 8) {
1017 /* Undo too much lookahead. The next read will be byte aligned
1018 * so we can discard unused bits in the last meaningful byte. */
1019 bytebuffer_offset--;
1020 bytebuffer[bytebuffer_offset] = gunzip_bb & 0xff;
1026 free(gunzip_window);
1027 free(gunzip_crc_table);
1032 /* External entry points */
1036 IF_DESKTOP(long long) int FAST_FUNC
1037 inflate_unzip(transformer_aux_data_t *aux, int in, int out)
1039 IF_DESKTOP(long long) int n;
1044 to_read = aux->bytes_in;
1045 // bytebuffer_max = 0x8000;
1046 bytebuffer_offset = 4;
1047 bytebuffer = xmalloc(bytebuffer_max);
1048 n = inflate_unzip_internal(PASS_STATE in, out);
1051 aux->crc32 = gunzip_crc;
1052 aux->bytes_out = gunzip_bytes_out;
1062 /* Top up the input buffer with at least n bytes. */
1063 static int top_up(STATE_PARAM unsigned n)
1065 int count = bytebuffer_size - bytebuffer_offset;
1067 if (count < (int)n) {
1068 memmove(bytebuffer, &bytebuffer[bytebuffer_offset], count);
1069 bytebuffer_offset = 0;
1070 bytebuffer_size = full_read(gunzip_src_fd, &bytebuffer[count], bytebuffer_max - count);
1071 if ((int)bytebuffer_size < 0) {
1072 bb_error_msg(bb_msg_read_error);
1075 bytebuffer_size += count;
1076 if (bytebuffer_size < n)
1082 static uint16_t buffer_read_le_u16(STATE_PARAM_ONLY)
1085 #if BB_LITTLE_ENDIAN
1086 move_from_unaligned16(res, &bytebuffer[bytebuffer_offset]);
1088 res = bytebuffer[bytebuffer_offset];
1089 res |= bytebuffer[bytebuffer_offset + 1] << 8;
1091 bytebuffer_offset += 2;
1095 static uint32_t buffer_read_le_u32(STATE_PARAM_ONLY)
1098 #if BB_LITTLE_ENDIAN
1099 move_from_unaligned32(res, &bytebuffer[bytebuffer_offset]);
1101 res = bytebuffer[bytebuffer_offset];
1102 res |= bytebuffer[bytebuffer_offset + 1] << 8;
1103 res |= bytebuffer[bytebuffer_offset + 2] << 16;
1104 res |= bytebuffer[bytebuffer_offset + 3] << 24;
1106 bytebuffer_offset += 4;
1110 static int check_header_gzip(STATE_PARAM transformer_aux_data_t *aux)
1113 unsigned char raw[8];
1118 uint8_t xtra_flags_UNUSED;
1119 uint8_t os_flags_UNUSED;
1123 char BUG_header[sizeof(header) == 8 ? 1 : -1];
1127 * Rewind bytebuffer. We use the beginning because the header has 8
1128 * bytes, leaving enough for unwinding afterwards.
1130 bytebuffer_size -= bytebuffer_offset;
1131 memmove(bytebuffer, &bytebuffer[bytebuffer_offset], bytebuffer_size);
1132 bytebuffer_offset = 0;
1134 if (!top_up(PASS_STATE 8))
1136 memcpy(header.raw, &bytebuffer[bytebuffer_offset], 8);
1137 bytebuffer_offset += 8;
1139 /* Check the compression method */
1140 if (header.formatted.gz_method != 8) {
1144 if (header.formatted.flags & 0x04) {
1145 /* bit 2 set: extra field present */
1146 unsigned extra_short;
1148 if (!top_up(PASS_STATE 2))
1150 extra_short = buffer_read_le_u16(PASS_STATE_ONLY);
1151 if (!top_up(PASS_STATE extra_short))
1153 /* Ignore extra field */
1154 bytebuffer_offset += extra_short;
1157 /* Discard original name and file comment if any */
1158 /* bit 3 set: original file name present */
1159 /* bit 4 set: file comment present */
1160 if (header.formatted.flags & 0x18) {
1163 if (!top_up(PASS_STATE 1))
1165 } while (bytebuffer[bytebuffer_offset++] != 0);
1166 if ((header.formatted.flags & 0x18) != 0x18)
1168 header.formatted.flags &= ~0x18;
1173 aux->mtime = SWAP_LE32(header.formatted.mtime);
1175 /* Read the header checksum */
1176 if (header.formatted.flags & 0x02) {
1177 if (!top_up(PASS_STATE 2))
1179 bytebuffer_offset += 2;
1184 IF_DESKTOP(long long) int FAST_FUNC
1185 unpack_gz_stream(transformer_aux_data_t *aux, int src_fd, int dst_fd)
1188 IF_DESKTOP(long long) int total, n;
1191 if (check_signature16(aux, src_fd, GZIP_MAGIC))
1198 // bytebuffer_max = 0x8000;
1199 bytebuffer = xmalloc(bytebuffer_max);
1200 gunzip_src_fd = src_fd;
1203 if (!check_header_gzip(PASS_STATE aux)) {
1204 bb_error_msg("corrupted data");
1209 n = inflate_unzip_internal(PASS_STATE src_fd, dst_fd);
1216 if (!top_up(PASS_STATE 8)) {
1217 bb_error_msg("corrupted data");
1222 /* Validate decompression - crc */
1223 v32 = buffer_read_le_u32(PASS_STATE_ONLY);
1224 if ((~gunzip_crc) != v32) {
1225 bb_error_msg("crc error");
1230 /* Validate decompression - size */
1231 v32 = buffer_read_le_u32(PASS_STATE_ONLY);
1232 if ((uint32_t)gunzip_bytes_out != v32) {
1233 bb_error_msg("incorrect length");
1237 if (!top_up(PASS_STATE 2))
1240 if (bytebuffer[bytebuffer_offset] == 0x1f
1241 && bytebuffer[bytebuffer_offset + 1] == 0x8b
1243 bytebuffer_offset += 2;
1246 /* GNU gzip says: */
1247 /*bb_error_msg("decompression OK, trailing garbage ignored");*/