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 <andersee@debian.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
15 * standard busybox functions by Glenn McGrath <bug1@optushome.com.au>
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.
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.
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
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.
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.
43 #include <sys/types.h>
52 static FILE *in_file
, *out_file
;
54 /* these are freed by gz_close */
55 static unsigned char *window
;
56 static unsigned long *crc_table
= NULL
;
58 static unsigned long crc
; /* shift register contents */
61 * window size--must be a power of two, and
62 * at least 32K for zip's deflate method
64 static const int WSIZE
= 0x8000;
66 /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
67 static const int BMAX
= 16; /* maximum bit length of any code (16 for explode) */
68 static const int N_MAX
= 288; /* maximum number of codes in any set */
70 static long bytes_out
; /* number of output bytes */
71 static unsigned long outcnt
; /* bytes in output buffer */
73 static unsigned hufts
; /* track memory usage */
74 static unsigned long bb
; /* bit buffer */
75 static unsigned bk
; /* bits in bit buffer */
77 typedef struct huft_s
{
78 unsigned char e
; /* number of extra bits or operation */
79 unsigned char b
; /* number of bits in this code or subcode */
81 unsigned short n
; /* literal, length base, or distance base */
82 struct huft_s
*t
; /* pointer to next level of table */
86 static const unsigned short mask_bits
[] = {
88 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
89 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
92 //static int error_number = 0;
93 /* ========================================================================
94 * Signal and error handler.
97 static void abort_gzip()
99 error_msg("gzip aborted\n");
103 static void make_crc_table()
105 unsigned long table_entry
; /* crc shift register */
106 unsigned long poly
= 0; /* polynomial exclusive-or pattern */
107 int i
; /* counter for all possible eight bit values */
108 int k
; /* byte being shifted into crc apparatus */
110 /* terms of polynomial defining this crc (except x^32): */
111 static int p
[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26};
113 /* initial shift register value */
115 crc_table
= (unsigned long *) xmalloc(256 * sizeof(unsigned long));
117 /* Make exclusive-or pattern from polynomial (0xedb88320) */
118 for (i
= 0; i
< sizeof(p
)/sizeof(int); i
++)
119 poly
|= 1L << (31 - p
[i
]);
121 /* Compute and print table of CRC's, five per line */
122 for (i
= 0; i
< 256; i
++) {
124 /* The idea to initialize the register with the byte instead of
125 * zero was stolen from Haruhiko Okumura's ar002
127 for (k
= 8; k
; k
--) {
128 table_entry
= table_entry
& 1 ? (table_entry
>> 1) ^ poly
: table_entry
>> 1;
130 crc_table
[i
]=table_entry
;
134 /* ===========================================================================
135 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
136 * (Used for the decompressed data only.)
138 static void flush_window(void)
145 for (n
= 0; n
< outcnt
; n
++) {
146 crc
= crc_table
[((int) crc
^ (window
[n
])) & 0xff] ^ (crc
>> 8);
149 if (fwrite(window
, 1, outcnt
, out_file
) != outcnt
) {
151 * The Parent process may not be interested in all the data we have,
152 * in which case it will rudely close its end of the pipe and
153 * wait for us to exit.
158 error_msg("Couldnt write");
161 bytes_out
+= (unsigned long) outcnt
;
166 * Free the malloc'ed tables built by huft_build(), which makes a linked
167 * list of the tables it made, with the links in a dummy first entry of
171 static int huft_free(huft_t
*t
)
175 /* Go through linked list, freeing from the malloced (t[-1]) address. */
177 while (p
!= (huft_t
*) NULL
) {
185 /* Given a list of code lengths and a maximum table size, make a set of
186 * tables to decode that set of codes. Return zero on success, one if
187 * the given code set is incomplete (the tables are still built in this
188 * case), two if the input is invalid (all zero length codes or an
189 * oversubscribed set of lengths), and three if not enough memory.
191 * b: code lengths in bits (all assumed <= BMAX)
192 * n: number of codes (assumed <= N_MAX)
193 * s: number of simple-valued codes (0..s-1)
194 * d: list of base values for non-simple codes
195 * e: list of extra bits for non-simple codes
196 * t: result: starting table
197 * m: maximum lookup bits, returns actual
199 static int huft_build(unsigned int *b
, const unsigned int n
, const unsigned int s
,
200 const unsigned short *d
, const unsigned short *e
, huft_t
**t
, int *m
)
202 unsigned a
; /* counter for codes of length k */
203 unsigned c
[BMAX
+ 1]; /* bit length count table */
204 unsigned f
; /* i repeats in table every f entries */
205 int g
; /* maximum code length */
206 int h
; /* table level */
207 unsigned i
; /* counter, current code */
208 unsigned j
; /* counter */
209 int k
; /* number of bits in current code */
210 int l
; /* bits per table (returned in m) */
211 unsigned *p
; /* pointer into c[], b[], or v[] */
212 huft_t
*q
; /* points to current table */
213 huft_t r
; /* table entry for structure assignment */
214 huft_t
*u
[BMAX
]; /* table stack */
215 unsigned v
[N_MAX
]; /* values in order of bit length */
216 int w
; /* bits before this table == (l * h) */
217 unsigned x
[BMAX
+ 1]; /* bit offsets, then code stack */
218 unsigned *xp
; /* pointer into x */
219 int y
; /* number of dummy codes added */
220 unsigned z
; /* number of entries in current table */
222 /* Generate counts for each bit length */
223 memset ((void *)(c
), 0, sizeof(c
));
227 c
[*p
]++; /* assume all entries <= BMAX */
228 p
++; /* Can't combine with above line (Solaris bug) */
230 if (c
[0] == n
) { /* null input--all zero length codes */
231 *t
= (huft_t
*) NULL
;
236 /* Find minimum and maximum length, bound *m by those */
238 for (j
= 1; j
<= BMAX
; j
++)
241 k
= j
; /* minimum code length */
242 if ((unsigned) l
< j
)
244 for (i
= BMAX
; i
; i
--)
247 g
= i
; /* maximum code length */
248 if ((unsigned) l
> i
)
252 /* Adjust last length count to fill out codes, if needed */
253 for (y
= 1 << j
; j
< i
; j
++, y
<<= 1)
255 return 2; /* bad input: more codes than bits */
260 /* Generate starting offsets into the value table for each length */
264 while (--i
) { /* note that i == g from above */
268 /* Make a table of values in order of bit lengths */
276 /* Generate the Huffman codes and for each, make the table entries */
277 x
[0] = i
= 0; /* first Huffman code is zero */
278 p
= v
; /* grab values in bit order */
279 h
= -1; /* no tables yet--level -1 */
280 w
= -l
; /* bits decoded == (l * h) */
281 u
[0] = (huft_t
*) NULL
; /* just to keep compilers happy */
282 q
= (huft_t
*) NULL
; /* ditto */
285 /* go through the bit lengths (k already is bits in shortest code) */
286 for (; k
<= g
; k
++) {
289 /* here i is the Huffman code of length k bits for value *p */
290 /* make tables up to required level */
293 w
+= l
; /* previous table always l bits */
295 /* compute minimum size table less than or equal to l bits */
296 z
= (z
= g
- w
) > (unsigned) l
? l
: z
; /* upper limit on table size */
297 if ((f
= 1 << (j
= k
- w
)) > a
+ 1) { /* try a k-w bit table *//* too few codes for k-w bit table */
298 f
-= a
+ 1; /* deduct codes from patterns left */
300 while (++j
< z
) { /* try smaller tables up to z bits */
301 if ((f
<<= 1) <= *++xp
)
302 break; /* enough codes to use up j bits */
303 f
-= *xp
; /* else deduct codes from patterns */
306 z
= 1 << j
; /* table entries for j-bit table */
308 /* allocate and link in new table */
309 if ((q
= (huft_t
*) xmalloc((z
+ 1) * sizeof(huft_t
))) == NULL
) {
313 return 3; /* not enough memory */
315 hufts
+= z
+ 1; /* track memory usage */
316 *t
= q
+ 1; /* link to list for huft_free() */
317 *(t
= &(q
->v
.t
)) = NULL
;
318 u
[h
] = ++q
; /* table starts after link */
320 /* connect to last table, if there is one */
322 x
[h
] = i
; /* save pattern for backing up */
323 r
.b
= (unsigned char) l
; /* bits to dump before this table */
324 r
.e
= (unsigned char) (16 + j
); /* bits in this table */
325 r
.v
.t
= q
; /* pointer to this table */
326 j
= i
>> (w
- l
); /* (get around Turbo C bug) */
327 u
[h
- 1][j
] = r
; /* connect to last table */
331 /* set up table entry in r */
332 r
.b
= (unsigned char) (k
- w
);
334 r
.e
= 99; /* out of values--invalid code */
336 r
.e
= (unsigned char) (*p
< 256 ? 16 : 15); /* 256 is end-of-block code */
337 r
.v
.n
= (unsigned short) (*p
); /* simple code is just the value */
338 p
++; /* one compiler does not like *p++ */
340 r
.e
= (unsigned char) e
[*p
- s
]; /* non-simple--look up in lists */
344 /* fill code-like entries with r */
346 for (j
= i
>> w
; j
< z
; j
+= f
)
349 /* backwards increment the k-bit code i */
350 for (j
= 1 << (k
- 1); i
& j
; j
>>= 1)
354 /* backup over finished tables */
355 while ((i
& ((1 << w
) - 1)) != x
[h
]) {
356 h
--; /* don't need to update q */
361 /* Return true (1) if we were given an incomplete table */
362 return y
!= 0 && g
!= 1;
366 * inflate (decompress) the codes in a deflated (compressed) block.
367 * Return an error code or zero if it all goes ok.
369 * tl, td: literal/length and distance decoder tables
370 * bl, bd: number of bits decoded by tl[] and td[]
372 static int inflate_codes(huft_t
*tl
, huft_t
*td
, int bl
, int bd
)
374 unsigned long e
; /* table entry flag/number of extra bits */
375 unsigned long n
, d
; /* length and index for copy */
376 unsigned long w
; /* current window position */
377 huft_t
*t
; /* pointer to table entry */
378 unsigned ml
, md
; /* masks for bl and bd bits */
379 unsigned long b
; /* bit buffer */
380 unsigned k
; /* number of bits in bit buffer */
382 /* make local copies of globals */
383 b
= bb
; /* initialize bit buffer */
385 w
= outcnt
; /* initialize window position */
387 /* inflate the coded data */
388 ml
= mask_bits
[bl
]; /* precompute masks for speed */
390 for (;;) { /* do until end of block */
391 while (k
< (unsigned) bl
) {
392 b
|= ((unsigned long)fgetc(in_file
)) << k
;
395 if ((e
= (t
= tl
+ ((unsigned) b
& ml
))->e
) > 16)
404 b
|= ((unsigned long)fgetc(in_file
)) << k
;
407 } while ((e
= (t
= t
->v
.t
+ ((unsigned) b
& mask_bits
[e
]))->e
) > 16);
410 if (e
== 16) { /* then it's a literal */
411 window
[w
++] = (unsigned char) t
->v
.n
;
417 } else { /* it's an EOB or a length */
419 /* exit if end of block */
424 /* get length of block to copy */
426 b
|= ((unsigned long)fgetc(in_file
)) << k
;
429 n
= t
->v
.n
+ ((unsigned) b
& mask_bits
[e
]);
433 /* decode distance of block to copy */
434 while (k
< (unsigned) bd
) {
435 b
|= ((unsigned long)fgetc(in_file
)) << k
;
439 if ((e
= (t
= td
+ ((unsigned) b
& md
))->e
) > 16)
447 b
|= ((unsigned long)fgetc(in_file
)) << k
;
450 } while ((e
= (t
= t
->v
.t
+ ((unsigned) b
& mask_bits
[e
]))->e
) > 16);
454 b
|= ((unsigned long)fgetc(in_file
)) << k
;
457 d
= w
- t
->v
.n
- ((unsigned) b
& mask_bits
[e
]);
463 n
-= (e
= (e
= WSIZE
- ((d
&= WSIZE
- 1) > w
? d
: w
)) > n
? n
: e
);
464 #if !defined(NOMEMCPY) && !defined(DEBUG)
465 if (w
- d
>= e
) { /* (this test assumes unsigned comparison) */
466 memcpy(window
+ w
, window
+ d
, e
);
469 } else /* do it slow to avoid memcpy() overlap */
470 #endif /* !NOMEMCPY */
472 window
[w
++] = window
[d
++];
483 /* restore the globals from the locals */
484 outcnt
= w
; /* restore global window pointer */
485 bb
= b
; /* restore global bit buffer */
493 * decompress an inflated block
496 * GLOBAL VARIABLES: bb, kk,
498 static int inflate_block(int *e
)
500 unsigned t
; /* block type */
501 unsigned long b
; /* bit buffer */
502 unsigned k
; /* number of bits in bit buffer */
503 static unsigned short cplens
[] = { /* Copy lengths for literal codes 257..285 */
504 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
505 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
507 /* note: see note #13 above about the 258 in this list. */
508 static unsigned short cplext
[] = { /* Extra bits for literal codes 257..285 */
509 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
510 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99
512 static unsigned short cpdist
[] = { /* Copy offsets for distance codes 0..29 */
513 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
514 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
515 8193, 12289, 16385, 24577
517 static unsigned short cpdext
[] = { /* Extra bits for distance codes */
518 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
519 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
523 /* make local bit buffer */
527 /* read in last block bit */
529 b
|= ((unsigned long)fgetc(in_file
)) << k
;
536 /* read in block type */
538 b
|= ((unsigned long)fgetc(in_file
)) << k
;
541 t
= (unsigned) b
& 3;
545 /* restore the global bit buffer */
549 /* inflate that block type */
551 case 0: /* Inflate stored */
553 unsigned long n
; /* number of bytes in block */
554 unsigned long w
; /* current window position */
555 unsigned long b_stored
; /* bit buffer */
556 unsigned long k_stored
; /* number of bits in bit buffer */
558 /* make local copies of globals */
559 b_stored
= bb
; /* initialize bit buffer */
561 w
= outcnt
; /* initialize window position */
563 /* go to byte boundary */
568 /* get the length and its complement */
569 while (k_stored
< 16) {
570 b_stored
|= ((unsigned long)fgetc(in_file
)) << k_stored
;
573 n
= ((unsigned) b_stored
& 0xffff);
576 while (k_stored
< 16) {
577 b_stored
|= ((unsigned long)fgetc(in_file
)) << k_stored
;
580 if (n
!= (unsigned) ((~b_stored
) & 0xffff)) {
581 return 1; /* error in compressed data */
586 /* read and output the compressed data */
588 while (k_stored
< 8) {
589 b_stored
|= ((unsigned long)fgetc(in_file
)) << k_stored
;
592 window
[w
++] = (unsigned char) b_stored
;
593 if (w
== (unsigned long)WSIZE
) {
602 /* restore the globals from the locals */
603 outcnt
= w
; /* restore global window pointer */
604 bb
= b_stored
; /* restore global bit buffer */
608 case 1: /* Inflate fixed
609 * decompress an inflated type 1 (fixed Huffman codes) block. We should
610 * either replace this with a custom decoder, or at least precompute the
614 int i
; /* temporary variable */
615 huft_t
*tl
; /* literal/length code table */
616 huft_t
*td
; /* distance code table */
617 int bl
; /* lookup bits for tl */
618 int bd
; /* lookup bits for td */
619 unsigned int l
[288]; /* length list for huft_build */
621 /* set up literal table */
622 for (i
= 0; i
< 144; i
++) {
625 for (; i
< 256; i
++) {
628 for (; i
< 280; i
++) {
631 for (; i
< 288; i
++) { /* make a complete, but wrong code set */
635 if ((i
= huft_build(l
, 288, 257, cplens
, cplext
, &tl
, &bl
)) != 0) {
639 /* set up distance table */
640 for (i
= 0; i
< 30; i
++) { /* make an incomplete code set */
644 if ((i
= huft_build(l
, 30, 0, cpdist
, cpdext
, &td
, &bd
)) > 1) {
649 /* decompress until an end-of-block code */
650 if (inflate_codes(tl
, td
, bl
, bd
)) {
656 /* free the decoding tables, return */
661 case 2: /* Inflate dynamic */
663 /* Tables for deflate from PKZIP's appnote.txt. */
664 static unsigned border
[] = { /* Order of the bit length code lengths */
665 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
667 int dbits
= 6; /* bits in base distance lookup table */
668 int lbits
= 9; /* bits in base literal/length lookup table */
670 int i
; /* temporary variables */
672 unsigned l
; /* last length */
673 unsigned m
; /* mask for bit lengths table */
674 unsigned n
; /* number of lengths to get */
675 huft_t
*tl
; /* literal/length code table */
676 huft_t
*td
; /* distance code table */
677 int bl
; /* lookup bits for tl */
678 int bd
; /* lookup bits for td */
679 unsigned nb
; /* number of bit length codes */
680 unsigned nl
; /* number of literal/length codes */
681 unsigned nd
; /* number of distance codes */
683 unsigned ll
[286 + 30]; /* literal/length and distance code lengths */
684 unsigned long b_dynamic
; /* bit buffer */
685 unsigned k_dynamic
; /* number of bits in bit buffer */
687 /* make local bit buffer */
691 /* read in table lengths */
692 while (k_dynamic
< 5) {
693 b_dynamic
|= ((unsigned long)fgetc(in_file
)) << k_dynamic
;
696 nl
= 257 + ((unsigned) b_dynamic
& 0x1f); /* number of literal/length codes */
699 while (k_dynamic
< 5) {
700 b_dynamic
|= ((unsigned long)fgetc(in_file
)) << k_dynamic
;
703 nd
= 1 + ((unsigned) b_dynamic
& 0x1f); /* number of distance codes */
706 while (k_dynamic
< 4) {
707 b_dynamic
|= ((unsigned long)fgetc(in_file
)) << k_dynamic
;
710 nb
= 4 + ((unsigned) b_dynamic
& 0xf); /* number of bit length codes */
713 if (nl
> 286 || nd
> 30) {
714 return 1; /* bad lengths */
717 /* read in bit-length-code lengths */
718 for (j
= 0; j
< nb
; j
++) {
719 while (k_dynamic
< 3) {
720 b_dynamic
|= ((unsigned long)fgetc(in_file
)) << k_dynamic
;
723 ll
[border
[j
]] = (unsigned) b_dynamic
& 7;
727 for (; j
< 19; j
++) {
731 /* build decoding table for trees--single level, 7 bit lookup */
733 if ((i
= huft_build(ll
, 19, 19, NULL
, NULL
, &tl
, &bl
)) != 0) {
737 return i
; /* incomplete code set */
740 /* read in literal and distance code lengths */
744 while ((unsigned) i
< n
) {
745 while (k_dynamic
< (unsigned) bl
) {
746 b_dynamic
|= ((unsigned long)fgetc(in_file
)) << k_dynamic
;
749 j
= (td
= tl
+ ((unsigned) b_dynamic
& m
))->b
;
753 if (j
< 16) { /* length of code in bits (0..15) */
754 ll
[i
++] = l
= j
; /* save last length in l */
756 else if (j
== 16) { /* repeat last length 3 to 6 times */
757 while (k_dynamic
< 2) {
758 b_dynamic
|= ((unsigned long)fgetc(in_file
)) << k_dynamic
;
761 j
= 3 + ((unsigned) b_dynamic
& 3);
764 if ((unsigned) i
+ j
> n
) {
770 } else if (j
== 17) { /* 3 to 10 zero length codes */
771 while (k_dynamic
< 3) {
772 b_dynamic
|= ((unsigned long)fgetc(in_file
)) << k_dynamic
;
775 j
= 3 + ((unsigned) b_dynamic
& 7);
778 if ((unsigned) i
+ j
> n
) {
785 } else { /* j == 18: 11 to 138 zero length codes */
786 while (k_dynamic
< 7) {
787 b_dynamic
|= ((unsigned long)fgetc(in_file
)) << k_dynamic
;
790 j
= 11 + ((unsigned) b_dynamic
& 0x7f);
793 if ((unsigned) i
+ j
> n
) {
803 /* free decoding table for trees */
806 /* restore the global bit buffer */
810 /* build the decoding tables for literal/length and distance codes */
812 if ((i
= huft_build(ll
, nl
, 257, cplens
, cplext
, &tl
, &bl
)) != 0) {
814 error_msg("Incomplete literal tree");
817 return i
; /* incomplete code set */
820 if ((i
= huft_build(ll
+ nl
, nd
, 0, cpdist
, cpdext
, &td
, &bd
)) != 0) {
822 error_msg("incomplete distance tree");
826 return i
; /* incomplete code set */
829 /* decompress until an end-of-block code */
830 if (inflate_codes(tl
, td
, bl
, bd
)) {
836 /* free the decoding tables, return */
848 * decompress an inflated entry
850 * GLOBAL VARIABLES: outcnt, bk, bb, hufts, inptr
854 int e
; /* last block flag */
855 int r
; /* result code */
856 unsigned h
= 0; /* maximum struct huft's malloc'ed */
858 /* initialize window, bit buffer */
863 /* decompress until the last block */
866 if ((r
= inflate_block(&e
)) != 0) {
874 /* Undo too much lookahead. The next read will be byte aligned so we
875 * can discard unused bits in the last meaningful byte. */
878 ungetc((bb
<< bk
), in_file
);
881 /* flush out window */
888 /* ===========================================================================
889 * Unzip in to out. This routine works on both gzip and pkzip files.
891 * IN assertions: the buffer inbuf contains already the beginning of
892 * the compressed data, from offsets inptr to insize-1 included.
893 * The magic header has already been checked. The output buffer is cleared.
894 * in, out: input and output file descriptors
896 extern int unzip(FILE *l_in_file
, FILE *l_out_file
)
898 const int extra_field
= 0x04; /* bit 2 set: extra field present */
899 const int orig_name
= 0x08; /* bit 3 set: original file name present */
900 const int comment
= 0x10; /* bit 4 set: file comment present */
901 unsigned char buf
[8]; /* extended local header */
902 unsigned char flags
; /* compression flags */
903 char magic
[2]; /* magic header */
905 typedef void (*sig_type
) (int);
906 int exit_code
=0; /* program exit code */
910 out_file
= l_out_file
;
912 if (signal(SIGINT
, SIG_IGN
) != SIG_IGN
) {
913 (void) signal(SIGINT
, (sig_type
) abort_gzip
);
916 // if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
917 // (void) signal(SIGTERM, (sig_type) abort_gzip);
921 if (signal(SIGHUP
, SIG_IGN
) != SIG_IGN
) {
922 (void) signal(SIGHUP
, (sig_type
) abort_gzip
);
926 signal(SIGPIPE
, SIG_IGN
);
928 /* Allocate all global buffers (for DYN_ALLOC option) */
929 window
= xmalloc((size_t)(((2L*WSIZE
)+1L)*sizeof(unsigned char)));
933 magic
[0] = fgetc(in_file
);
934 magic
[1] = fgetc(in_file
);
936 /* Magic header for gzip files, 1F 8B = \037\213 */
937 if (memcmp(magic
, "\037\213", 2) != 0) {
938 error_msg("Invalid gzip magic");
942 method
= (int) fgetc(in_file
);
944 error_msg("unknown method %d -- get newer version of gzip", method
);
949 flags
= (unsigned char) fgetc(in_file
);
951 /* Ignore time stamp(4), extra flags(1), OS type(1) */
952 for (i
= 0; i
< 6; i
++)
955 if ((flags
& extra_field
) != 0) {
957 extra
= fgetc(in_file
);
958 extra
+= fgetc(in_file
) << 8;
960 for (i
= 0; i
< extra
; i
++)
964 /* Discard original name if any */
965 if ((flags
& orig_name
) != 0) {
966 while (fgetc(in_file
) != 0); /* null */
969 /* Discard file comment if any */
970 if ((flags
& comment
) != 0) {
971 while (fgetc(in_file
) != 0); /* null */
986 perror_msg("inflate");
988 } else if (res
!= 0) {
989 error_msg("invalid compressed data--format violated");
994 error_msg("internal error, invalid method");
998 /* Get the crc and original length
999 * crc32 (see algorithm.doc)
1000 * uncompressed input size modulo 2^32
1002 fread(buf
, 1, 8, in_file
);
1004 /* Validate decompression - crc */
1005 if (!exit_code
&& (unsigned int)((buf
[0] | (buf
[1] << 8)) |((buf
[2] | (buf
[3] << 8)) << 16)) != (crc
^ 0xffffffffL
)) {
1006 error_msg("invalid compressed data--crc error");
1009 /* Validate decompression - size */
1010 if (!exit_code
&& ((buf
[4] | (buf
[5] << 8)) |((buf
[6] | (buf
[7] << 8)) << 16)) != (unsigned long) bytes_out
) {
1011 error_msg("invalid compressed data--length error");