954ee61a8b8882e4768fc2c610093ba141c86267
[project/opkg-lede.git] / libbb / unzip.c
1 /* vi: set sw=4 ts=4: */
2 /*
3 * gunzip implementation for busybox
4 *
5 * Based on GNU gzip v1.2.4 Copyright (C) 1992-1993 Jean-loup Gailly.
6 *
7 * Originally adjusted for busybox by Sven Rudolph <sr1@inf.tu-dresden.de>
8 * based on gzip sources
9 *
10 * Adjusted further by Erik Andersen <andersee@debian.org> to support
11 * files as well as stdin/stdout, and to generally behave itself wrt
12 * command line handling.
13 *
14 * General cleanup to better adhere to the style guide and make use of
15 * standard busybox functions by Glenn McGrath <bug1@optushome.com.au>
16 *
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License as published by
19 * the Free Software Foundation; either version 2 of the License, or
20 * (at your option) any later version.
21 *
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
25 * General Public License for more details.
26 *
27 * You should have received a copy of the GNU General Public License
28 * along with this program; if not, write to the Free Software
29 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
30 *
31 *
32 * gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
33 * Copyright (C) 1992-1993 Jean-loup Gailly
34 * The unzip code was written and put in the public domain by Mark Adler.
35 * Portions of the lzw code are derived from the public domain 'compress'
36 * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
37 * Ken Turkowski, Dave Mack and Peter Jannesen.
38 *
39 * See the license_msg below and the file COPYING for the software license.
40 * See the file algorithm.doc for the compression algorithms and file formats.
41 */
42
43 #include <sys/types.h>
44 #include <sys/wait.h>
45 #include <signal.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include "libbb.h"
49
50 static FILE *in_file, *out_file;
51
52 /* these are freed by gz_close */
53 static unsigned char *window;
54 static unsigned long *crc_table = NULL;
55
56 static unsigned long crc; /* shift register contents */
57
58 /* Return codes from gzip */
59 static const int ERROR = 1;
60
61 /*
62 * window size--must be a power of two, and
63 * at least 32K for zip's deflate method
64 */
65 static const int WSIZE = 0x8000;
66
67 /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
68 static const int BMAX = 16; /* maximum bit length of any code (16 for explode) */
69 static const int N_MAX = 288; /* maximum number of codes in any set */
70
71 static long bytes_out; /* number of output bytes */
72 static unsigned long outcnt; /* bytes in output buffer */
73
74 static unsigned hufts; /* track memory usage */
75 static unsigned long bb; /* bit buffer */
76 static unsigned bk; /* bits in bit buffer */
77
78 typedef struct huft_s {
79 unsigned char e; /* number of extra bits or operation */
80 unsigned char b; /* number of bits in this code or subcode */
81 union {
82 unsigned short n; /* literal, length base, or distance base */
83 struct huft_s *t; /* pointer to next level of table */
84 } v;
85 } huft_t;
86
87 static const unsigned short mask_bits[] = {
88 0x0000,
89 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
90 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
91 };
92
93 //static int error_number = 0;
94 /* ========================================================================
95 * Signal and error handler.
96 */
97
98 static void abort_gzip()
99 {
100 error_msg("gzip aborted\n");
101 exit(ERROR);
102 }
103
104 static void make_crc_table()
105 {
106 unsigned long table_entry; /* crc shift register */
107 unsigned long poly = 0; /* polynomial exclusive-or pattern */
108 int i; /* counter for all possible eight bit values */
109 int k; /* byte being shifted into crc apparatus */
110
111 /* terms of polynomial defining this crc (except x^32): */
112 static int p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26};
113
114 /* initial shift register value */
115 crc = 0xffffffffL;
116 crc_table = (unsigned long *) malloc(256 * sizeof(unsigned long));
117
118 /* Make exclusive-or pattern from polynomial (0xedb88320) */
119 for (i = 0; i < sizeof(p)/sizeof(int); i++)
120 poly |= 1L << (31 - p[i]);
121
122 /* Compute and print table of CRC's, five per line */
123 for (i = 0; i < 256; i++) {
124 table_entry = i;
125 /* The idea to initialize the register with the byte instead of
126 * zero was stolen from Haruhiko Okumura's ar002
127 */
128 for (k = 8; k; k--) {
129 table_entry = table_entry & 1 ? (table_entry >> 1) ^ poly : table_entry >> 1;
130 }
131 crc_table[i]=table_entry;
132 }
133 }
134
135 /* ===========================================================================
136 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
137 * (Used for the decompressed data only.)
138 */
139 static void flush_window(void)
140 {
141 int n;
142
143 if (outcnt == 0)
144 return;
145
146 for (n = 0; n < outcnt; n++) {
147 crc = crc_table[((int) crc ^ (window[n])) & 0xff] ^ (crc >> 8);
148 }
149
150 if (fwrite(window, 1, outcnt, out_file) != outcnt) {
151 error_msg_and_die("Couldnt write");
152 }
153 bytes_out += (unsigned long) outcnt;
154 outcnt = 0;
155 }
156
157 /*
158 * Free the malloc'ed tables built by huft_build(), which makes a linked
159 * list of the tables it made, with the links in a dummy first entry of
160 * each table.
161 * t: table to free
162 */
163 static int huft_free(huft_t *t)
164 {
165 huft_t *p, *q;
166
167 /* Go through linked list, freeing from the malloced (t[-1]) address. */
168 p = t;
169 while (p != (huft_t *) NULL) {
170 q = (--p)->v.t;
171 free((char *) p);
172 p = q;
173 }
174 return 0;
175 }
176
177 /* Given a list of code lengths and a maximum table size, make a set of
178 * tables to decode that set of codes. Return zero on success, one if
179 * the given code set is incomplete (the tables are still built in this
180 * case), two if the input is invalid (all zero length codes or an
181 * oversubscribed set of lengths), and three if not enough memory.
182 *
183 * b: code lengths in bits (all assumed <= BMAX)
184 * n: number of codes (assumed <= N_MAX)
185 * s: number of simple-valued codes (0..s-1)
186 * d: list of base values for non-simple codes
187 * e: list of extra bits for non-simple codes
188 * t: result: starting table
189 * m: maximum lookup bits, returns actual
190 */
191 static int huft_build(unsigned int *b, const unsigned int n, const unsigned int s,
192 const unsigned short *d, const unsigned short *e, huft_t **t, int *m)
193 {
194 unsigned a; /* counter for codes of length k */
195 unsigned c[BMAX + 1]; /* bit length count table */
196 unsigned f; /* i repeats in table every f entries */
197 int g; /* maximum code length */
198 int h; /* table level */
199 register unsigned i; /* counter, current code */
200 register unsigned j; /* counter */
201 register int k; /* number of bits in current code */
202 int l; /* bits per table (returned in m) */
203 register unsigned *p; /* pointer into c[], b[], or v[] */
204 register huft_t *q; /* points to current table */
205 huft_t r; /* table entry for structure assignment */
206 huft_t *u[BMAX]; /* table stack */
207 unsigned v[N_MAX]; /* values in order of bit length */
208 register int w; /* bits before this table == (l * h) */
209 unsigned x[BMAX + 1]; /* bit offsets, then code stack */
210 unsigned *xp; /* pointer into x */
211 int y; /* number of dummy codes added */
212 unsigned z; /* number of entries in current table */
213
214 /* Generate counts for each bit length */
215 memset ((void *)(c), 0, sizeof(c));
216 p = b;
217 i = n;
218 do {
219 c[*p]++; /* assume all entries <= BMAX */
220 p++; /* Can't combine with above line (Solaris bug) */
221 } while (--i);
222 if (c[0] == n) { /* null input--all zero length codes */
223 *t = (huft_t *) NULL;
224 *m = 0;
225 return 0;
226 }
227
228 /* Find minimum and maximum length, bound *m by those */
229 l = *m;
230 for (j = 1; j <= BMAX; j++)
231 if (c[j])
232 break;
233 k = j; /* minimum code length */
234 if ((unsigned) l < j)
235 l = j;
236 for (i = BMAX; i; i--)
237 if (c[i])
238 break;
239 g = i; /* maximum code length */
240 if ((unsigned) l > i)
241 l = i;
242 *m = l;
243
244 /* Adjust last length count to fill out codes, if needed */
245 for (y = 1 << j; j < i; j++, y <<= 1)
246 if ((y -= c[j]) < 0)
247 return 2; /* bad input: more codes than bits */
248 if ((y -= c[i]) < 0)
249 return 2;
250 c[i] += y;
251
252 /* Generate starting offsets into the value table for each length */
253 x[1] = j = 0;
254 p = c + 1;
255 xp = x + 2;
256 while (--i) { /* note that i == g from above */
257 *xp++ = (j += *p++);
258 }
259
260 /* Make a table of values in order of bit lengths */
261 p = b;
262 i = 0;
263 do {
264 if ((j = *p++) != 0)
265 v[x[j]++] = i;
266 } while (++i < n);
267
268 /* Generate the Huffman codes and for each, make the table entries */
269 x[0] = i = 0; /* first Huffman code is zero */
270 p = v; /* grab values in bit order */
271 h = -1; /* no tables yet--level -1 */
272 w = -l; /* bits decoded == (l * h) */
273 u[0] = (huft_t *) NULL; /* just to keep compilers happy */
274 q = (huft_t *) NULL; /* ditto */
275 z = 0; /* ditto */
276
277 /* go through the bit lengths (k already is bits in shortest code) */
278 for (; k <= g; k++) {
279 a = c[k];
280 while (a--) {
281 /* here i is the Huffman code of length k bits for value *p */
282 /* make tables up to required level */
283 while (k > w + l) {
284 h++;
285 w += l; /* previous table always l bits */
286
287 /* compute minimum size table less than or equal to l bits */
288 z = (z = g - w) > (unsigned) l ? l : z; /* upper limit on table size */
289 if ((f = 1 << (j = k - w)) > a + 1) { /* try a k-w bit table *//* too few codes for k-w bit table */
290 f -= a + 1; /* deduct codes from patterns left */
291 xp = c + k;
292 while (++j < z) { /* try smaller tables up to z bits */
293 if ((f <<= 1) <= *++xp)
294 break; /* enough codes to use up j bits */
295 f -= *xp; /* else deduct codes from patterns */
296 }
297 }
298 z = 1 << j; /* table entries for j-bit table */
299
300 /* allocate and link in new table */
301 if ((q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t))) == NULL) {
302 if (h) {
303 huft_free(u[0]);
304 }
305 return 3; /* not enough memory */
306 }
307 hufts += z + 1; /* track memory usage */
308 *t = q + 1; /* link to list for huft_free() */
309 *(t = &(q->v.t)) = NULL;
310 u[h] = ++q; /* table starts after link */
311
312 /* connect to last table, if there is one */
313 if (h) {
314 x[h] = i; /* save pattern for backing up */
315 r.b = (unsigned char) l; /* bits to dump before this table */
316 r.e = (unsigned char) (16 + j); /* bits in this table */
317 r.v.t = q; /* pointer to this table */
318 j = i >> (w - l); /* (get around Turbo C bug) */
319 u[h - 1][j] = r; /* connect to last table */
320 }
321 }
322
323 /* set up table entry in r */
324 r.b = (unsigned char) (k - w);
325 if (p >= v + n)
326 r.e = 99; /* out of values--invalid code */
327 else if (*p < s) {
328 r.e = (unsigned char) (*p < 256 ? 16 : 15); /* 256 is end-of-block code */
329 r.v.n = (unsigned short) (*p); /* simple code is just the value */
330 p++; /* one compiler does not like *p++ */
331 } else {
332 r.e = (unsigned char) e[*p - s]; /* non-simple--look up in lists */
333 r.v.n = d[*p++ - s];
334 }
335
336 /* fill code-like entries with r */
337 f = 1 << (k - w);
338 for (j = i >> w; j < z; j += f)
339 q[j] = r;
340
341 /* backwards increment the k-bit code i */
342 for (j = 1 << (k - 1); i & j; j >>= 1)
343 i ^= j;
344 i ^= j;
345
346 /* backup over finished tables */
347 while ((i & ((1 << w) - 1)) != x[h]) {
348 h--; /* don't need to update q */
349 w -= l;
350 }
351 }
352 }
353 /* Return true (1) if we were given an incomplete table */
354 return y != 0 && g != 1;
355 }
356
357 /*
358 * inflate (decompress) the codes in a deflated (compressed) block.
359 * Return an error code or zero if it all goes ok.
360 *
361 * tl, td: literal/length and distance decoder tables
362 * bl, bd: number of bits decoded by tl[] and td[]
363 */
364 static int inflate_codes(huft_t *tl, huft_t *td, int bl, int bd)
365 {
366 register unsigned long e; /* table entry flag/number of extra bits */
367 unsigned long n, d; /* length and index for copy */
368 unsigned long w; /* current window position */
369 huft_t *t; /* pointer to table entry */
370 unsigned ml, md; /* masks for bl and bd bits */
371 register unsigned long b; /* bit buffer */
372 register unsigned k; /* number of bits in bit buffer */
373
374 /* make local copies of globals */
375 b = bb; /* initialize bit buffer */
376 k = bk;
377 w = outcnt; /* initialize window position */
378
379 /* inflate the coded data */
380 ml = mask_bits[bl]; /* precompute masks for speed */
381 md = mask_bits[bd];
382 for (;;) { /* do until end of block */
383 while (k < (unsigned) bl) {
384 b |= ((unsigned long)fgetc(in_file)) << k;
385 k += 8;
386 }
387 if ((e = (t = tl + ((unsigned) b & ml))->e) > 16)
388 do {
389 if (e == 99) {
390 return 1;
391 }
392 b >>= t->b;
393 k -= t->b;
394 e -= 16;
395 while (k < e) {
396 b |= ((unsigned long)fgetc(in_file)) << k;
397 k += 8;
398 }
399 } while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
400 b >>= t->b;
401 k -= t->b;
402 if (e == 16) { /* then it's a literal */
403 window[w++] = (unsigned char) t->v.n;
404 if (w == WSIZE) {
405 outcnt=(w),
406 flush_window();
407 w = 0;
408 }
409 } else { /* it's an EOB or a length */
410
411 /* exit if end of block */
412 if (e == 15) {
413 break;
414 }
415
416 /* get length of block to copy */
417 while (k < e) {
418 b |= ((unsigned long)fgetc(in_file)) << k;
419 k += 8;
420 }
421 n = t->v.n + ((unsigned) b & mask_bits[e]);
422 b >>= e;
423 k -= e;
424
425 /* decode distance of block to copy */
426 while (k < (unsigned) bd) {
427 b |= ((unsigned long)fgetc(in_file)) << k;
428 k += 8;
429 }
430
431 if ((e = (t = td + ((unsigned) b & md))->e) > 16)
432 do {
433 if (e == 99)
434 return 1;
435 b >>= t->b;
436 k -= t->b;
437 e -= 16;
438 while (k < e) {
439 b |= ((unsigned long)fgetc(in_file)) << k;
440 k += 8;
441 }
442 } while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
443 b >>= t->b;
444 k -= t->b;
445 while (k < e) {
446 b |= ((unsigned long)fgetc(in_file)) << k;
447 k += 8;
448 }
449 d = w - t->v.n - ((unsigned) b & mask_bits[e]);
450 b >>= e;
451 k -= e;
452
453 /* do the copy */
454 do {
455 n -= (e = (e = WSIZE - ((d &= WSIZE - 1) > w ? d : w)) > n ? n : e);
456 #if !defined(NOMEMCPY) && !defined(DEBUG)
457 if (w - d >= e) { /* (this test assumes unsigned comparison) */
458 memcpy(window + w, window + d, e);
459 w += e;
460 d += e;
461 } else /* do it slow to avoid memcpy() overlap */
462 #endif /* !NOMEMCPY */
463 do {
464 window[w++] = window[d++];
465 } while (--e);
466 if (w == WSIZE) {
467 outcnt=(w),
468 flush_window();
469 w = 0;
470 }
471 } while (n);
472 }
473 }
474
475 /* restore the globals from the locals */
476 outcnt = w; /* restore global window pointer */
477 bb = b; /* restore global bit buffer */
478 bk = k;
479
480 /* done */
481 return 0;
482 }
483
484 /*
485 * decompress an inflated block
486 * e: last block flag
487 *
488 * GLOBAL VARIABLES: bb, kk,
489 */
490 static int inflate_block(int *e)
491 {
492 unsigned t; /* block type */
493 register unsigned long b; /* bit buffer */
494 register unsigned k; /* number of bits in bit buffer */
495 static unsigned short cplens[] = { /* Copy lengths for literal codes 257..285 */
496 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
497 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
498 };
499 /* note: see note #13 above about the 258 in this list. */
500 static unsigned short cplext[] = { /* Extra bits for literal codes 257..285 */
501 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
502 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99
503 }; /* 99==invalid */
504 static unsigned short cpdist[] = { /* Copy offsets for distance codes 0..29 */
505 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
506 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
507 8193, 12289, 16385, 24577
508 };
509 static unsigned short cpdext[] = { /* Extra bits for distance codes */
510 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
511 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
512 12, 12, 13, 13
513 };
514
515 /* make local bit buffer */
516 b = bb;
517 k = bk;
518
519 /* read in last block bit */
520 while (k < 1) {
521 b |= ((unsigned long)fgetc(in_file)) << k;
522 k += 8;
523 }
524 *e = (int) b & 1;
525 b >>= 1;
526 k -= 1;
527
528 /* read in block type */
529 while (k < 2) {
530 b |= ((unsigned long)fgetc(in_file)) << k;
531 k += 8;
532 }
533 t = (unsigned) b & 3;
534 b >>= 2;
535 k -= 2;
536
537 /* restore the global bit buffer */
538 bb = b;
539 bk = k;
540
541 /* inflate that block type */
542 switch (t) {
543 case 0: /* Inflate stored */
544 {
545 unsigned long n; /* number of bytes in block */
546 unsigned long w; /* current window position */
547 register unsigned long b_stored; /* bit buffer */
548 register unsigned long k_stored; /* number of bits in bit buffer */
549
550 /* make local copies of globals */
551 b_stored = bb; /* initialize bit buffer */
552 k_stored = bk;
553 w = outcnt; /* initialize window position */
554
555 /* go to byte boundary */
556 n = k_stored & 7;
557 b_stored >>= n;
558 k_stored -= n;
559
560 /* get the length and its complement */
561 while (k_stored < 16) {
562 b_stored |= ((unsigned long)fgetc(in_file)) << k_stored;
563 k_stored += 8;
564 }
565 n = ((unsigned) b_stored & 0xffff);
566 b_stored >>= 16;
567 k_stored -= 16;
568 while (k_stored < 16) {
569 b_stored |= ((unsigned long)fgetc(in_file)) << k_stored;
570 k_stored += 8;
571 }
572 if (n != (unsigned) ((~b_stored) & 0xffff)) {
573 return 1; /* error in compressed data */
574 }
575 b_stored >>= 16;
576 k_stored -= 16;
577
578 /* read and output the compressed data */
579 while (n--) {
580 while (k_stored < 8) {
581 b_stored |= ((unsigned long)fgetc(in_file)) << k_stored;
582 k_stored += 8;
583 }
584 window[w++] = (unsigned char) b_stored;
585 if (w == (unsigned long)WSIZE) {
586 outcnt=(w),
587 flush_window();
588 w = 0;
589 }
590 b_stored >>= 8;
591 k_stored -= 8;
592 }
593
594 /* restore the globals from the locals */
595 outcnt = w; /* restore global window pointer */
596 bb = b_stored; /* restore global bit buffer */
597 bk = k_stored;
598 return 0;
599 }
600 case 1: /* Inflate fixed
601 * decompress an inflated type 1 (fixed Huffman codes) block. We should
602 * either replace this with a custom decoder, or at least precompute the
603 * Huffman tables.
604 */
605 {
606 int i; /* temporary variable */
607 huft_t *tl; /* literal/length code table */
608 huft_t *td; /* distance code table */
609 int bl; /* lookup bits for tl */
610 int bd; /* lookup bits for td */
611 unsigned int l[288]; /* length list for huft_build */
612
613 /* set up literal table */
614 for (i = 0; i < 144; i++) {
615 l[i] = 8;
616 }
617 for (; i < 256; i++) {
618 l[i] = 9;
619 }
620 for (; i < 280; i++) {
621 l[i] = 7;
622 }
623 for (; i < 288; i++) { /* make a complete, but wrong code set */
624 l[i] = 8;
625 }
626 bl = 7;
627 if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0) {
628 return i;
629 }
630
631 /* set up distance table */
632 for (i = 0; i < 30; i++) { /* make an incomplete code set */
633 l[i] = 5;
634 }
635 bd = 5;
636 if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1) {
637 huft_free(tl);
638 return i;
639 }
640
641 /* decompress until an end-of-block code */
642 if (inflate_codes(tl, td, bl, bd))
643 return 1;
644
645 /* free the decoding tables, return */
646 huft_free(tl);
647 huft_free(td);
648 return 0;
649 }
650 case 2: /* Inflate dynamic */
651 {
652 /* Tables for deflate from PKZIP's appnote.txt. */
653 static unsigned border[] = { /* Order of the bit length code lengths */
654 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
655 };
656 int dbits = 6; /* bits in base distance lookup table */
657 int lbits = 9; /* bits in base literal/length lookup table */
658
659 int i; /* temporary variables */
660 unsigned j;
661 unsigned l; /* last length */
662 unsigned m; /* mask for bit lengths table */
663 unsigned n; /* number of lengths to get */
664 huft_t *tl; /* literal/length code table */
665 huft_t *td; /* distance code table */
666 int bl; /* lookup bits for tl */
667 int bd; /* lookup bits for td */
668 unsigned nb; /* number of bit length codes */
669 unsigned nl; /* number of literal/length codes */
670 unsigned nd; /* number of distance codes */
671
672 unsigned ll[286 + 30]; /* literal/length and distance code lengths */
673 register unsigned long b_dynamic; /* bit buffer */
674 register unsigned k_dynamic; /* number of bits in bit buffer */
675
676 /* make local bit buffer */
677 b_dynamic = bb;
678 k_dynamic = bk;
679
680 /* read in table lengths */
681 while (k_dynamic < 5) {
682 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
683 k_dynamic += 8;
684 }
685 nl = 257 + ((unsigned) b_dynamic & 0x1f); /* number of literal/length codes */
686 b_dynamic >>= 5;
687 k_dynamic -= 5;
688 while (k_dynamic < 5) {
689 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
690 k_dynamic += 8;
691 }
692 nd = 1 + ((unsigned) b_dynamic & 0x1f); /* number of distance codes */
693 b_dynamic >>= 5;
694 k_dynamic -= 5;
695 while (k_dynamic < 4) {
696 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
697 k_dynamic += 8;
698 }
699 nb = 4 + ((unsigned) b_dynamic & 0xf); /* number of bit length codes */
700 b_dynamic >>= 4;
701 k_dynamic -= 4;
702 if (nl > 286 || nd > 30) {
703 return 1; /* bad lengths */
704 }
705
706 /* read in bit-length-code lengths */
707 for (j = 0; j < nb; j++) {
708 while (k_dynamic < 3) {
709 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
710 k_dynamic += 8;
711 }
712 ll[border[j]] = (unsigned) b_dynamic & 7;
713 b_dynamic >>= 3;
714 k_dynamic -= 3;
715 }
716 for (; j < 19; j++) {
717 ll[border[j]] = 0;
718 }
719
720 /* build decoding table for trees--single level, 7 bit lookup */
721 bl = 7;
722 if ((i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl)) != 0) {
723 if (i == 1) {
724 huft_free(tl);
725 }
726 return i; /* incomplete code set */
727 }
728
729 /* read in literal and distance code lengths */
730 n = nl + nd;
731 m = mask_bits[bl];
732 i = l = 0;
733 while ((unsigned) i < n) {
734 while (k_dynamic < (unsigned) bl) {
735 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
736 k_dynamic += 8;
737 }
738 j = (td = tl + ((unsigned) b_dynamic & m))->b;
739 b_dynamic >>= j;
740 k_dynamic -= j;
741 j = td->v.n;
742 if (j < 16) { /* length of code in bits (0..15) */
743 ll[i++] = l = j; /* save last length in l */
744 }
745 else if (j == 16) { /* repeat last length 3 to 6 times */
746 while (k_dynamic < 2) {
747 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
748 k_dynamic += 8;
749 }
750 j = 3 + ((unsigned) b_dynamic & 3);
751 b_dynamic >>= 2;
752 k_dynamic -= 2;
753 if ((unsigned) i + j > n) {
754 return 1;
755 }
756 while (j--) {
757 ll[i++] = l;
758 }
759 } else if (j == 17) { /* 3 to 10 zero length codes */
760 while (k_dynamic < 3) {
761 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
762 k_dynamic += 8;
763 }
764 j = 3 + ((unsigned) b_dynamic & 7);
765 b_dynamic >>= 3;
766 k_dynamic -= 3;
767 if ((unsigned) i + j > n) {
768 return 1;
769 }
770 while (j--) {
771 ll[i++] = 0;
772 }
773 l = 0;
774 } else { /* j == 18: 11 to 138 zero length codes */
775 while (k_dynamic < 7) {
776 b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic;
777 k_dynamic += 8;
778 }
779 j = 11 + ((unsigned) b_dynamic & 0x7f);
780 b_dynamic >>= 7;
781 k_dynamic -= 7;
782 if ((unsigned) i + j > n) {
783 return 1;
784 }
785 while (j--) {
786 ll[i++] = 0;
787 }
788 l = 0;
789 }
790 }
791
792 /* free decoding table for trees */
793 huft_free(tl);
794
795 /* restore the global bit buffer */
796 bb = b_dynamic;
797 bk = k_dynamic;
798
799 /* build the decoding tables for literal/length and distance codes */
800 bl = lbits;
801 if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0) {
802 if (i == 1) {
803 error_msg("Incomplete literal tree");
804 huft_free(tl);
805 }
806 return i; /* incomplete code set */
807 }
808 bd = dbits;
809 if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0) {
810 if (i == 1) {
811 error_msg("incomplete distance tree");
812 huft_free(td);
813 }
814 huft_free(tl);
815 return i; /* incomplete code set */
816 }
817
818 /* decompress until an end-of-block code */
819 if (inflate_codes(tl, td, bl, bd))
820 return 1;
821
822 /* free the decoding tables, return */
823 huft_free(tl);
824 huft_free(td);
825 return 0;
826 }
827 default:
828 /* bad block type */
829 return 2;
830 }
831 }
832
833 /*
834 * decompress an inflated entry
835 *
836 * GLOBAL VARIABLES: outcnt, bk, bb, hufts, inptr
837 */
838 static int inflate()
839 {
840 int e; /* last block flag */
841 int r; /* result code */
842 unsigned h = 0; /* maximum struct huft's malloc'ed */
843
844 /* initialize window, bit buffer */
845 outcnt = 0;
846 bk = 0;
847 bb = 0;
848
849 /* decompress until the last block */
850 do {
851 hufts = 0;
852 if ((r = inflate_block(&e)) != 0) {
853 return r;
854 }
855 if (hufts > h) {
856 h = hufts;
857 }
858 } while (!e);
859
860 /* Undo too much lookahead. The next read will be byte aligned so we
861 * can discard unused bits in the last meaningful byte. */
862 while (bk >= 8) {
863 bk -= 8;
864 ungetc((bb << bk), in_file);
865 }
866
867 /* flush out window */
868 flush_window();
869
870 /* return success */
871 return 0;
872 }
873
874 /* ===========================================================================
875 * Unzip in to out. This routine works on both gzip and pkzip files.
876 *
877 * IN assertions: the buffer inbuf contains already the beginning of
878 * the compressed data, from offsets inptr to insize-1 included.
879 * The magic header has already been checked. The output buffer is cleared.
880 * in, out: input and output file descriptors
881 */
882 extern int unzip(FILE *l_in_file, FILE *l_out_file)
883 {
884 const int extra_field = 0x04; /* bit 2 set: extra field present */
885 const int orig_name = 0x08; /* bit 3 set: original file name present */
886 const int comment = 0x10; /* bit 4 set: file comment present */
887 unsigned char buf[8]; /* extended local header */
888 unsigned char flags; /* compression flags */
889 char magic[2]; /* magic header */
890 int method;
891 typedef void (*sig_type) (int);
892 int exit_code=0; /* program exit code */
893 int i;
894
895 in_file = l_in_file;
896 out_file = l_out_file;
897
898 if (signal(SIGINT, SIG_IGN) != SIG_IGN) {
899 (void) signal(SIGINT, (sig_type) abort_gzip);
900 }
901 #ifdef SIGTERM
902 // if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
903 // (void) signal(SIGTERM, (sig_type) abort_gzip);
904 // }
905 #endif
906 #ifdef SIGHUP
907 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
908 (void) signal(SIGHUP, (sig_type) abort_gzip);
909 }
910 #endif
911
912 /* Allocate all global buffers (for DYN_ALLOC option) */
913 window = xmalloc((size_t)(((2L*WSIZE)+1L)*sizeof(unsigned char)));
914 outcnt = 0;
915 bytes_out = 0L;
916
917 magic[0] = fgetc(in_file);
918 magic[1] = fgetc(in_file);
919
920 /* Magic header for gzip files, 1F 8B = \037\213 */
921 if (memcmp(magic, "\037\213", 2) != 0) {
922 error_msg("Invalid gzip magic");
923 return EXIT_FAILURE;
924 }
925
926 method = (int) fgetc(in_file);
927 if (method != 8) {
928 error_msg("unknown method %d -- get newer version of gzip", method);
929 exit_code = 1;
930 return -1;
931 }
932
933 flags = (unsigned char) fgetc(in_file);
934
935 /* Ignore time stamp(4), extra flags(1), OS type(1) */
936 for (i = 0; i < 6; i++)
937 fgetc(in_file);
938
939 if ((flags & extra_field) != 0) {
940 size_t extra;
941 extra = fgetc(in_file);
942 extra += fgetc(in_file) << 8;
943
944 for (i = 0; i < extra; i++)
945 fgetc(in_file);
946 }
947
948 /* Discard original name if any */
949 if ((flags & orig_name) != 0) {
950 while (fgetc(in_file) != 0); /* null */
951 }
952
953 /* Discard file comment if any */
954 if ((flags & comment) != 0) {
955 while (fgetc(in_file) != 0); /* null */
956 }
957
958 if (method < 0) {
959 printf("it failed\n");
960 return(exit_code); /* error message already emitted */
961 }
962
963 make_crc_table();
964
965 /* Decompress */
966 if (method == 8) {
967
968 int res = inflate();
969
970 if (res == 3) {
971 error_msg(memory_exhausted);
972 exit_code = 1;
973 } else if (res != 0) {
974 error_msg("invalid compressed data--format violated");
975 exit_code = 1;
976 }
977
978 } else {
979 error_msg("internal error, invalid method");
980 exit_code = 1;
981 }
982
983 /* Get the crc and original length
984 * crc32 (see algorithm.doc)
985 * uncompressed input size modulo 2^32
986 */
987 fread(buf, 1, 8, in_file);
988
989 /* Validate decompression - crc */
990 if (!exit_code && (unsigned int)((buf[0] | (buf[1] << 8)) |((buf[2] | (buf[3] << 8)) << 16)) != (crc ^ 0xffffffffL)) {
991 error_msg("invalid compressed data--crc error");
992 exit_code = 1;
993 }
994 /* Validate decompression - size */
995 if (!exit_code && ((buf[4] | (buf[5] << 8)) |((buf[6] | (buf[7] << 8)) << 16)) != (unsigned long) bytes_out) {
996 error_msg("invalid compressed data--length error");
997 exit_code = 1;
998 }
999
1000 free(window);
1001 free(crc_table);
1002
1003 window = NULL;
1004 crc_table = NULL;
1005
1006 return exit_code;
1007 }
1008
1009 /*
1010 * This needs access to global variables wondow and crc_table, so its not in its own file.
1011 */
1012 extern void gz_close(int gunzip_pid)
1013 {
1014 if (kill(gunzip_pid, SIGTERM) == -1) {
1015 error_msg_and_die("*** Couldnt kill old gunzip process *** aborting");
1016 }
1017
1018 if (waitpid(gunzip_pid, NULL, 0) == -1) {
1019 printf("Couldnt wait ?");
1020 }
1021 free(window);
1022 free(crc_table);
1023 }