1 /* vi: set sw=4 ts=4: */
3 * Gzip implementation for busybox
5 * Based on GNU gzip 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@lineo.com>, <andersee@debian.org>
11 * to support files as well as stdin/stdout, and to generally behave itself wrt
12 * command line handling.
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
33 /* These defines are very important for BusyBox. Without these,
34 * huge chunks of ram are pre-allocated making the BusyBox bss
35 * size Freaking Huge(tm), which is a bad thing.*/
39 #define BB_DECLARE_EXTERN
40 #define bb_need_memory_exhausted
41 #define bb_need_name_too_long
45 /* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
46 * Copyright (C) 1992-1993 Jean-loup Gailly
47 * The unzip code was written and put in the public domain by Mark Adler.
48 * Portions of the lzw code are derived from the public domain 'compress'
49 * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
50 * Ken Turkowski, Dave Mack and Peter Jannesen.
52 * See the license_msg below and the file COPYING for the software license.
53 * See the file algorithm.doc for the compression algorithms and file formats.
57 static char *license_msg[] = {
58 " Copyright (C) 1992-1993 Jean-loup Gailly",
59 " This program is free software; you can redistribute it and/or modify",
60 " it under the terms of the GNU General Public License as published by",
61 " the Free Software Foundation; either version 2, or (at your option)",
62 " any later version.",
64 " This program is distributed in the hope that it will be useful,",
65 " but WITHOUT ANY WARRANTY; without even the implied warranty of",
66 " MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the",
67 " GNU General Public License for more details.",
69 " You should have received a copy of the GNU General Public License",
70 " along with this program; if not, write to the Free Software",
71 " Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.",
76 /* Compress files with zip algorithm and 'compress' interface.
77 * See usage() and help() functions below for all options.
79 * file.gz: compressed file with same mode, owner, and utimes
80 * or stdout with -c option or if stdin used as input.
81 * If the output file name had to be truncated, the original name is kept
82 * in the compressed file.
83 * On MSDOS, file.tmp -> file.tmz. On VMS, file.tmp -> file.tmp-gz.
85 * Using gz on MSDOS would create too many file name conflicts. For
86 * example, foo.txt -> foo.tgz (.tgz must be reserved as shorthand for
87 * tar.gz). Similarly, foo.dir and foo.doc would both be mapped to foo.dgz.
88 * I also considered 12345678.txt -> 12345txt.gz but this truncates the name
89 * too heavily. There is no ideal solution given the MSDOS 8+3 limitation.
91 * For the meaning of all compilation flags, see comments in Makefile.in.
95 #include <sys/types.h>
99 /* #include "tailor.h" */
101 /* tailor.h -- target dependent definitions
102 * Copyright (C) 1992-1993 Jean-loup Gailly.
103 * This is free software; you can redistribute it and/or modify it under the
104 * terms of the GNU General Public License, see the file COPYING.
107 /* The target dependent definitions should be defined here only.
108 * The target dependent functions should be defined in tailor.c.
113 #define get_char() get_byte()
114 #define put_char(c) put_byte(c)
117 /* I don't like nested includes, but the string and io functions are used
121 #if !defined(NO_STRING_H) || defined(STDC_HEADERS)
123 # if !defined(STDC_HEADERS) && !defined(NO_MEMORY_H) && !defined(__GNUC__)
126 # define memzero(s, n) memset ((void *)(s), 0, (n))
128 # include <strings.h>
129 # define strchr index
130 # define strrchr rindex
131 # define memcpy(d, s, n) bcopy((s), (d), (n))
132 # define memcmp(s1, s2, n) bcmp((s1), (s2), (n))
133 # define memzero(s, n) bzero((s), (n))
137 # define RETSIGTYPE void
142 typedef unsigned char uch;
143 typedef unsigned short ush;
144 typedef unsigned long ulg;
146 /* Return codes from gzip */
151 /* Compression methods (see algorithm.doc) */
154 extern int method; /* compression method */
156 /* To save memory for 16 bit systems, some arrays are overlaid between
157 * the various modules:
158 * deflate: prev+head window d_buf l_buf outbuf
159 * unlzw: tab_prefix tab_suffix stack inbuf outbuf
160 * inflate: window inbuf
161 * unpack: window inbuf prefix_len
162 * unlzh: left+right window c_table inbuf c_len
163 * For compression, input is done in window[]. For decompression, output
164 * is done in window except for unlzw.
169 # define INBUFSIZ 0x2000 /* input buffer size */
171 # define INBUFSIZ 0x8000 /* input buffer size */
174 #define INBUF_EXTRA 64 /* required by unlzw() */
178 # define OUTBUFSIZ 8192 /* output buffer size */
180 # define OUTBUFSIZ 16384 /* output buffer size */
183 #define OUTBUF_EXTRA 2048 /* required by unlzw() */
189 # define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */
191 # define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */
195 /*#define DYN_ALLOC*/
198 # define EXTERN(type, array) extern type * array
199 # define DECLARE(type, array, size) type * array
200 # define ALLOC(type, array, size) { \
201 array = (type*)calloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \
202 if (array == NULL) errorMsg(memory_exhausted); \
204 # define FREE(array) {if (array != NULL) free(array), array=NULL;}
206 # define EXTERN(type, array) extern type array[]
207 # define DECLARE(type, array, size) type array[size]
208 # define ALLOC(type, array, size)
212 EXTERN(uch, inbuf); /* input buffer */
213 EXTERN(uch, outbuf); /* output buffer */
214 EXTERN(ush, d_buf); /* buffer for distances, see trees.c */
215 EXTERN(uch, window); /* Sliding window and suffix table (unlzw) */
216 #define tab_suffix window
218 # define tab_prefix prev /* hash link (see deflate.c) */
219 # define head (prev+WSIZE) /* hash head (see deflate.c) */
220 EXTERN(ush, tab_prefix); /* prefix code (see unlzw.c) */
222 # define tab_prefix0 prev
223 # define head tab_prefix1
224 EXTERN(ush, tab_prefix0); /* prefix for even codes */
225 EXTERN(ush, tab_prefix1); /* prefix for odd codes */
228 extern unsigned insize; /* valid bytes in inbuf */
229 extern unsigned inptr; /* index of next byte to be processed in inbuf */
230 extern unsigned outcnt; /* bytes in output buffer */
232 extern long bytes_in; /* number of input bytes */
233 extern long bytes_out; /* number of output bytes */
234 extern long header_bytes; /* number of bytes in gzip header */
236 extern long ifile_size; /* input file size, -1 for devices (debug only) */
238 typedef int file_t; /* Do not use stdio */
240 #define NO_FILE (-1) /* in memory compression */
243 #define GZIP_MAGIC "\037\213" /* Magic header for gzip files, 1F 8B */
246 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
247 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
248 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
249 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
250 #define COMMENT 0x10 /* bit 4 set: file comment present */
251 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
252 #define RESERVED 0xC0 /* bit 6,7: reserved */
255 # define WSIZE 0x8000 /* window size--must be a power of two, and */
256 #endif /* at least 32K for zip's deflate method */
259 #define MAX_MATCH 258
260 /* The minimum and maximum match lengths */
262 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
263 /* Minimum amount of lookahead, except at the end of the input file.
264 * See deflate.c for comments about the MIN_MATCH+1.
267 #define MAX_DIST (WSIZE-MIN_LOOKAHEAD)
268 /* In order to simplify the code, particularly on 16 bit machines, match
269 * distances are limited to MAX_DIST instead of WSIZE.
272 extern int exit_code; /* program exit code */
273 extern int verbose; /* be verbose (-v) */
274 extern int level; /* compression level */
275 extern int test; /* check .z file integrity */
276 extern int save_orig_name; /* set if original name must be saved */
278 #define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(0))
279 #define try_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(1))
281 /* put_byte is used for the compressed output, put_ubyte for the
282 * uncompressed output. However unlzw() uses window for its
283 * suffix table instead of its output buffer, so it does not use put_ubyte
284 * (to be cleaned up).
286 #define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
288 #define put_ubyte(c) {window[outcnt++]=(uch)(c); if (outcnt==WSIZE)\
291 /* Output a 16 bit value, lsb first */
292 #define put_short(w) \
293 { if (outcnt < OUTBUFSIZ-2) { \
294 outbuf[outcnt++] = (uch) ((w) & 0xff); \
295 outbuf[outcnt++] = (uch) ((ush)(w) >> 8); \
297 put_byte((uch)((w) & 0xff)); \
298 put_byte((uch)((ush)(w) >> 8)); \
302 /* Output a 32 bit value to the bit stream, lsb first */
303 #define put_long(n) { \
304 put_short((n) & 0xffff); \
305 put_short(((ulg)(n)) >> 16); \
308 #define seekable() 0 /* force sequential output */
309 #define translate_eol 0 /* no option -a yet */
311 #define tolow(c) (isupper(c) ? (c)-'A'+'a' : (c)) /* force to lower case */
313 /* Macros for getting two-byte and four-byte header values */
314 #define SH(p) ((ush)(uch)((p)[0]) | ((ush)(uch)((p)[1]) << 8))
315 #define LG(p) ((ulg)(SH(p)) | ((ulg)(SH((p)+2)) << 16))
317 /* Diagnostic functions */
319 # define Assert(cond,msg) {if(!(cond)) errorMsg(msg);}
320 # define Trace(x) fprintf x
321 # define Tracev(x) {if (verbose) fprintf x ;}
322 # define Tracevv(x) {if (verbose>1) fprintf x ;}
323 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
324 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
326 # define Assert(cond,msg)
331 # define Tracecv(c,x)
334 #define WARN(msg) {fprintf msg ; \
335 if (exit_code == OK) exit_code = WARNING;}
338 extern int unzip (int in, int out);
341 RETSIGTYPE abort_gzip (void);
344 void lm_init (int pack_level, ush * flags);
348 void ct_init (ush * attr, int *method);
349 int ct_tally (int dist, int lc);
350 ulg flush_block (char *buf, ulg stored_len, int eof);
353 void bi_init (file_t zipfile);
354 void send_bits (int value, int length);
355 unsigned bi_reverse (unsigned value, int length);
356 void bi_windup (void);
357 void copy_block (char *buf, unsigned len, int header);
360 extern ulg updcrc (uch * s, unsigned n);
361 extern void clear_bufs (void);
362 static int fill_inbuf (int eof_ok);
363 extern void flush_outbuf (void);
364 static void flush_window (void);
365 extern void write_buf (int fd, void * buf, unsigned cnt);
368 static char *basename (char *fname);
369 #endif /* not __linux__ */
370 void read_error_msg (void);
371 void write_error_msg (void);
374 static int inflate (void);
376 /* #include "lzw.h" */
378 /* lzw.h -- define the lzw functions.
379 * Copyright (C) 1992-1993 Jean-loup Gailly.
380 * This is free software; you can redistribute it and/or modify it under the
381 * terms of the GNU General Public License, see the file COPYING.
384 #if !defined(OF) && defined(lint)
391 #define INIT_BITS 9 /* Initial number of bits per code */
393 #define LZW_MAGIC "\037\235" /* Magic header for lzw files, 1F 9D */
395 #define BIT_MASK 0x1f /* Mask for 'number of compression bits' */
396 /* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free.
397 * It's a pity that old uncompress does not check bit 0x20. That makes
398 * extension of the format actually undesirable because old compress
399 * would just crash on the new format instead of giving a meaningful
400 * error message. It does check the number of bits, but it's more
401 * helpful to say "unsupported format, get a new version" than
402 * "can only handle 16 bits".
405 #define BLOCK_MODE 0x80
406 /* Block compression: if table is full and compression rate is dropping,
407 * clear the dictionary.
410 #define LZW_RESERVED 0x60 /* reserved bits */
412 #define CLEAR 256 /* flush the dictionary */
413 #define FIRST (CLEAR+1) /* first free entry */
415 extern int maxbits; /* max bits per code for LZW */
416 extern int block_mode; /* block compress mode -C compatible with 2.0 */
418 extern int lzw (int in, int out);
419 extern int unlzw (int in, int out);
422 /* #include "revision.h" */
424 /* revision.h -- define the version number
425 * Copyright (C) 1992-1993 Jean-loup Gailly.
426 * This is free software; you can redistribute it and/or modify it under the
427 * terms of the GNU General Public License, see the file COPYING.
430 #define VERSION "1.2.4"
432 #define REVDATE "18 Aug 93"
434 /* This version does not support compression into old compress format: */
445 typedef struct dirent dir_type;
447 # define NLENGTH(dirent) ((int)strlen((dirent)->d_name))
448 # define DIR_OPT "DIRENT"
450 # define NLENGTH(dirent) ((dirent)->d_namlen)
452 # include <sys/dir.h>
453 typedef struct direct dir_type;
455 # define DIR_OPT "SYSDIR"
458 # include <sys/ndir.h>
459 typedef struct direct dir_type;
461 # define DIR_OPT "SYSNDIR"
465 typedef struct direct dir_type;
467 # define DIR_OPT "NDIR"
470 # define DIR_OPT "NO_DIR"
475 #if !defined(S_ISDIR) && defined(S_IFDIR)
476 # define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
478 #if !defined(S_ISREG) && defined(S_IFREG)
479 # define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
481 typedef RETSIGTYPE(*sig_type) (int);
484 # define O_BINARY 0 /* creation mode for open() */
488 /* Pure BSD system? */
489 # include <sys/file.h>
491 # define O_CREAT FCREAT
494 # define O_EXCL FEXCL
499 # define S_IRUSR 0400
502 # define S_IWUSR 0200
504 #define RW_USER (S_IRUSR | S_IWUSR) /* creation mode for open() */
506 #ifndef MAX_PATH_LEN /* max pathname length */
508 # define MAX_PATH_LEN BUFSIZ
510 # define MAX_PATH_LEN 1024
520 off_t lseek (int fd, off_t offset, int whence);
526 DECLARE(uch, inbuf, INBUFSIZ + INBUF_EXTRA);
527 DECLARE(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA);
528 DECLARE(ush, d_buf, DIST_BUFSIZE);
529 DECLARE(uch, window, 2L * WSIZE);
531 DECLARE(ush, tab_prefix, 1L << BITS);
533 DECLARE(ush, tab_prefix0, 1L << (BITS - 1));
534 DECLARE(ush, tab_prefix1, 1L << (BITS - 1));
537 /* local variables */
539 int test_mode = 0; /* check file integrity option */
540 int foreground; /* set if program run in foreground */
541 int maxbits = BITS; /* max bits per code for LZW */
542 int method = DEFLATED; /* compression method */
543 int exit_code = OK; /* program exit code */
544 int last_member; /* set for .zip and .Z files */
545 int part_nb; /* number of parts in .gz file */
546 long ifile_size; /* input file size, -1 for devices (debug only) */
548 long bytes_in; /* number of input bytes */
549 long bytes_out; /* number of output bytes */
550 long total_in = 0; /* input bytes for all files */
551 long total_out = 0; /* output bytes for all files */
552 struct stat istat; /* status for input file */
553 int ifd; /* input file descriptor */
554 int ofd; /* output file descriptor */
555 unsigned insize; /* valid bytes in inbuf */
556 unsigned inptr; /* index of next byte to be processed in inbuf */
557 unsigned outcnt; /* bytes in output buffer */
559 long header_bytes; /* number of bytes in gzip header */
561 /* local functions */
563 local int get_method (int in);
565 #define strequ(s1, s2) (strcmp((s1),(s2)) == 0)
567 /* ======================================================================== */
568 int gunzip_main(int argc, char **argv)
570 int file_count; /* number of files to precess */
576 int delInputFile = 0;
580 char ifname[MAX_PATH_LEN + 1]; /* input file name */
581 char ofname[MAX_PATH_LEN + 1]; /* output file name */
583 if (strcmp(applet_name, "zcat") == 0) {
588 /* Parse any options */
589 while (--argc > 0 && **(++argv) == '-') {
590 if (*((*argv) + 1) == '\0') {
593 while (*(++(*argv))) {
615 if (isatty(fileno(stdin)) && fromstdin==1 && force==0)
616 fatalError( "data not read from terminal. Use -f to force it.\n");
617 if (isatty(fileno(stdout)) && tostdout==1 && force==0)
618 fatalError( "data not written to terminal. Use -f to force it.\n");
621 foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
623 (void) signal(SIGINT, (sig_type) abort_gzip);
626 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
627 (void) signal(SIGTERM, (sig_type) abort_gzip);
631 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
632 (void) signal(SIGHUP, (sig_type) abort_gzip);
636 file_count = argc - optind;
638 /* Allocate all global buffers (for DYN_ALLOC option) */
639 ALLOC(uch, inbuf, INBUFSIZ + INBUF_EXTRA);
640 ALLOC(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA);
641 ALLOC(ush, d_buf, DIST_BUFSIZE);
642 ALLOC(uch, window, 2L * WSIZE);
644 ALLOC(ush, tab_prefix, 1L << BITS);
646 ALLOC(ush, tab_prefix0, 1L << (BITS - 1));
647 ALLOC(ush, tab_prefix1, 1L << (BITS - 1));
650 if (fromstdin == 1) {
651 strcpy(ofname, "stdin");
653 inFileNum = fileno(stdin);
654 ifile_size = -1L; /* convention for unknown size */
656 /* Open up the input file */
659 if (strlen(*argv) > MAX_PATH_LEN) {
660 errorMsg(name_too_long);
663 strcpy(ifname, *argv);
665 /* Open input fille */
666 inFileNum = open(ifname, O_RDONLY);
671 /* Get the time stamp on the input file. */
672 result = stat(ifname, &statBuf);
677 ifile_size = statBuf.st_size;
681 /* And get to work */
682 strcpy(ofname, "stdout");
683 outFileNum = fileno(stdout);
685 clear_bufs(); /* clear input and output buffers */
688 /* Actually do the compression/decompression. */
689 unzip(inFileNum, outFileNum);
691 } else if (test_mode) {
692 /* Actually do the compression/decompression. */
697 /* And get to work */
698 if (strlen(ifname) > MAX_PATH_LEN - 4) {
699 errorMsg(name_too_long);
702 strcpy(ofname, ifname);
703 pos = strstr(ofname, ".gz");
708 pos = strstr(ofname, ".tgz");
716 /* Open output fille */
717 #if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
718 outFileNum = open(ofname, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW);
720 outFileNum = open(ofname, O_RDWR | O_CREAT | O_EXCL);
722 if (outFileNum < 0) {
726 /* Set permissions on the file */
727 fchmod(outFileNum, statBuf.st_mode);
729 clear_bufs(); /* clear input and output buffers */
732 /* Actually do the compression/decompression. */
733 result = unzip(inFileNum, outFileNum);
737 /* Delete the original file */
739 delFileName = ifname;
741 delFileName = ofname;
743 if (delInputFile == 1 && unlink(delFileName) < 0) {
752 /* ========================================================================
753 * Check the magic number of the input file and update ofname if an
754 * original name was given and tostdout is not set.
755 * Return the compression method, -1 for error, -2 for warning.
756 * Set inptr to the offset of the next byte to be processed.
757 * Updates time_stamp if there is one and --no-time is not used.
758 * This function may be called repeatedly for an input file consisting
759 * of several contiguous gzip'ed members.
760 * IN assertions: there is at least one remaining compressed member.
761 * If the member is a zip file, it must be the only one.
763 local int get_method(in)
764 int in; /* input file descriptor */
766 uch flags; /* compression flags */
767 char magic[2]; /* magic header */
769 magic[0] = (char) get_byte();
770 magic[1] = (char) get_byte();
771 method = -1; /* unknown yet */
772 part_nb++; /* number of parts in gzip file */
774 last_member = RECORD_IO;
775 /* assume multiple members in gzip file except for record oriented I/O */
777 if (memcmp(magic, GZIP_MAGIC, 2) == 0) {
779 method = (int) get_byte();
780 if (method != DEFLATED) {
781 errorMsg("unknown method %d -- get newer version of gzip\n",
786 flags = (uch) get_byte();
788 (ulg) get_byte(); /* Ignore time stamp */
793 (void) get_byte(); /* Ignore extra flags for the moment */
794 (void) get_byte(); /* Ignore OS type for the moment */
796 if ((flags & EXTRA_FIELD) != 0) {
797 unsigned len = (unsigned) get_byte();
799 len |= ((unsigned) get_byte()) << 8;
805 /* Discard original name if any */
806 if ((flags & ORIG_NAME) != 0) {
807 while (get_char() != 0) /* null */
811 /* Discard file comment if any */
812 if ((flags & COMMENT) != 0) {
813 while (get_char() != 0) /* null */
817 header_bytes = inptr + 2 * sizeof(long); /* include crc and size */
826 fprintf(stderr, "\nnot in gzip format\n");
830 WARN((stderr, "\ndecompression OK, trailing garbage ignored\n"));
835 /* ========================================================================
836 * Signal and error handler.
838 RETSIGTYPE abort_gzip()
843 /* unzip.c -- decompress files in gzip or pkzip format.
844 * Copyright (C) 1992-1993 Jean-loup Gailly
845 * This is free software; you can redistribute it and/or modify it under the
846 * terms of the GNU General Public License, see the file COPYING.
848 * The code in this file is derived from the file funzip.c written
849 * and put in the public domain by Mark Adler.
853 This version can extract files in gzip or pkzip format.
854 For the latter, only the first entry is extracted, and it has to be
855 either deflated or stored.
858 /* #include "crypt.h" */
860 /* crypt.h (dummy version) -- do not perform encryption
861 * Hardly worth copyrighting :-)
865 # undef CRYPT /* dummy version */
868 #define RAND_HEAD_LEN 12 /* length of encryption random header */
873 /* PKZIP header definitions */
874 #define LOCSIG 0x04034b50L /* four-byte lead-in (lsb first) */
875 #define LOCFLG 6 /* offset of bit flag */
876 #define CRPFLG 1 /* bit for encrypted entry */
877 #define EXTFLG 8 /* bit for extended local header */
878 #define LOCHOW 8 /* offset of compression method */
879 #define LOCTIM 10 /* file mod time (for decryption) */
880 #define LOCCRC 14 /* offset of crc */
881 #define LOCSIZ 18 /* offset of compressed size */
882 #define LOCLEN 22 /* offset of uncompressed length */
883 #define LOCFIL 26 /* offset of file name field length */
884 #define LOCEXT 28 /* offset of extra field length */
885 #define LOCHDR 30 /* size of local header, including sig */
886 #define EXTHDR 16 /* size of extended local header, inc sig */
891 char *key; /* not used--needed to link crypt.c */
892 int pkzip = 0; /* set for a pkzip file */
893 int ext_header = 0; /* set if extended local header */
895 /* ===========================================================================
896 * Unzip in to out. This routine works on both gzip and pkzip files.
898 * IN assertions: the buffer inbuf contains already the beginning of
899 * the compressed data, from offsets inptr to insize-1 included.
900 * The magic header has already been checked. The output buffer is cleared.
903 int in, out; /* input and output file descriptors */
905 ulg orig_crc = 0; /* original crc */
906 ulg orig_len = 0; /* original uncompressed length */
908 uch buf[EXTHDR]; /* extended local header */
912 method = get_method(ifd);
914 exit(exit_code); /* error message already emitted */
917 updcrc(NULL, 0); /* initialize crc */
919 if (pkzip && !ext_header) { /* crc and length at the end otherwise */
920 orig_crc = LG(inbuf + LOCCRC);
921 orig_len = LG(inbuf + LOCLEN);
925 if (method == DEFLATED) {
930 errorMsg(memory_exhausted);
931 } else if (res != 0) {
932 errorMsg("invalid compressed data--format violated");
936 errorMsg("internal error, invalid method");
939 /* Get the crc and original length */
941 /* crc32 (see algorithm.doc)
942 * uncompressed input size modulo 2^32
944 for (n = 0; n < 8; n++) {
945 buf[n] = (uch) get_byte(); /* may cause an error if EOF */
948 orig_len = LG(buf + 4);
950 } else if (ext_header) { /* If extended header, check it */
951 /* signature - 4bytes: 0x50 0x4b 0x07 0x08
953 * compressed size 4-bytes
954 * uncompressed size 4-bytes
956 for (n = 0; n < EXTHDR; n++) {
957 buf[n] = (uch) get_byte(); /* may cause an error if EOF */
959 orig_crc = LG(buf + 4);
960 orig_len = LG(buf + 12);
963 /* Validate decompression */
964 if (orig_crc != updcrc(outbuf, 0)) {
965 errorMsg("invalid compressed data--crc error");
967 if (orig_len != (ulg) bytes_out) {
968 errorMsg("invalid compressed data--length error");
971 /* Check if there are more entries in a pkzip file */
972 if (pkzip && inptr + 4 < insize && LG(inbuf + inptr) == LOCSIG) {
973 WARN((stderr, "has more than one entry--rest ignored\n"));
975 ext_header = pkzip = 0; /* for next file */
979 /* util.c -- utility functions for gzip support
980 * Copyright (C) 1992-1993 Jean-loup Gailly
981 * This is free software; you can redistribute it and/or modify it under the
982 * terms of the GNU General Public License, see the file COPYING.
987 #include <sys/types.h>
996 #if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
1002 static const ulg crc_32_tab[]; /* crc table, defined below */
1004 /* ===========================================================================
1005 * Run a set of bytes through the crc shift register. If s is a NULL
1006 * pointer, then initialize the crc shift register contents instead.
1007 * Return the current crc in either case.
1010 uch *s; /* pointer to bytes to pump through */
1011 unsigned n; /* number of bytes in s[] */
1013 register ulg c; /* temporary variable */
1015 static ulg crc = (ulg) 0xffffffffL; /* shift register contents */
1023 c = crc_32_tab[((int) c ^ (*s++)) & 0xff] ^ (c >> 8);
1027 return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
1030 /* ===========================================================================
1031 * Clear input and output buffers
1033 void clear_bufs(void)
1037 bytes_in = bytes_out = 0L;
1040 /* ===========================================================================
1041 * Fill the input buffer. This is called only when the buffer is empty.
1043 int fill_inbuf(eof_ok)
1044 int eof_ok; /* set if EOF acceptable as a result */
1048 /* Read as much as possible */
1052 len = read(ifd, (char *) inbuf + insize, INBUFSIZ - insize);
1053 if (len == 0 || len == EOF)
1056 } while (insize < INBUFSIZ);
1063 bytes_in += (ulg) insize;
1068 /* ===========================================================================
1069 * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
1070 * (used for the compressed data only)
1078 write_buf(ofd, (char *) outbuf, outcnt);
1079 bytes_out += (ulg) outcnt;
1083 /* ===========================================================================
1084 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
1085 * (Used for the decompressed data only.)
1091 updcrc(window, outcnt);
1094 write_buf(ofd, (char *) window, outcnt);
1095 bytes_out += (ulg) outcnt;
1099 /* ===========================================================================
1100 * Does the same as write(), but also handles partial pipe writes and checks
1103 void write_buf(fd, buf, cnt)
1110 while ((n = write(fd, buf, cnt)) != cnt) {
1111 if (n == (unsigned) (-1)) {
1115 buf = (void *) ((char *) buf + n);
1119 #if defined(NO_STRING_H) && !defined(STDC_HEADERS)
1121 /* Provide missing strspn and strcspn functions. */
1127 int strspn (const char *s, const char *accept);
1128 int strcspn (const char *s, const char *reject);
1130 /* ========================================================================
1131 * Return the length of the maximum initial segment
1132 * of s which contains only characters in accept.
1134 int strspn(s, accept)
1138 register const char *p;
1139 register const char *a;
1140 register int count = 0;
1142 for (p = s; *p != '\0'; ++p) {
1143 for (a = accept; *a != '\0'; ++a) {
1154 /* ========================================================================
1155 * Return the length of the maximum inital segment of s
1156 * which contains no characters from reject.
1158 int strcspn(s, reject)
1162 register int count = 0;
1164 while (*s != '\0') {
1165 if (strchr(reject, *s++) != NULL)
1172 #endif /* NO_STRING_H */
1175 /* ========================================================================
1178 void read_error_msg()
1180 fprintf(stderr, "\n");
1184 fprintf(stderr, "unexpected end of file\n");
1189 void write_error_msg()
1191 fprintf(stderr, "\n");
1197 /* ========================================================================
1198 * Table of CRC-32's of all single-byte values (made by makecrc.c)
1200 static const ulg crc_32_tab[] = {
1201 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
1202 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
1203 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
1204 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
1205 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
1206 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
1207 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
1208 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
1209 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
1210 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
1211 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
1212 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
1213 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
1214 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
1215 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
1216 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
1217 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
1218 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
1219 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
1220 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
1221 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
1222 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
1223 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
1224 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
1225 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
1226 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
1227 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
1228 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
1229 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
1230 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
1231 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
1232 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
1233 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
1234 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
1235 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
1236 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
1237 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
1238 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
1239 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
1240 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
1241 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
1242 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
1243 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
1244 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
1245 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
1246 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
1247 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
1248 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
1249 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
1250 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
1251 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
1255 /* inflate.c -- Not copyrighted 1992 by Mark Adler
1256 version c10p1, 10 January 1993 */
1258 /* You can do whatever you like with this source file, though I would
1259 prefer that if you modify it and redistribute it that you include
1260 comments to that effect with your name and the date. Thank you.
1261 [The history has been moved to the file ChangeLog.]
1265 Inflate deflated (PKZIP's method 8 compressed) data. The compression
1266 method searches for as much of the current string of bytes (up to a
1267 length of 258) in the previous 32K bytes. If it doesn't find any
1268 matches (of at least length 3), it codes the next byte. Otherwise, it
1269 codes the length of the matched string and its distance backwards from
1270 the current position. There is a single Huffman code that codes both
1271 single bytes (called "literals") and match lengths. A second Huffman
1272 code codes the distance information, which follows a length code. Each
1273 length or distance code actually represents a base value and a number
1274 of "extra" (sometimes zero) bits to get to add to the base value. At
1275 the end of each deflated block is a special end-of-block (EOB) literal/
1276 length code. The decoding process is basically: get a literal/length
1277 code; if EOB then done; if a literal, emit the decoded byte; if a
1278 length then get the distance and emit the referred-to bytes from the
1279 sliding window of previously emitted data.
1281 There are (currently) three kinds of inflate blocks: stored, fixed, and
1282 dynamic. The compressor deals with some chunk of data at a time, and
1283 decides which method to use on a chunk-by-chunk basis. A chunk might
1284 typically be 32K or 64K. If the chunk is uncompressible, then the
1285 "stored" method is used. In this case, the bytes are simply stored as
1286 is, eight bits per byte, with none of the above coding. The bytes are
1287 preceded by a count, since there is no longer an EOB code.
1289 If the data is compressible, then either the fixed or dynamic methods
1290 are used. In the dynamic method, the compressed data is preceded by
1291 an encoding of the literal/length and distance Huffman codes that are
1292 to be used to decode this block. The representation is itself Huffman
1293 coded, and so is preceded by a description of that code. These code
1294 descriptions take up a little space, and so for small blocks, there is
1295 a predefined set of codes, called the fixed codes. The fixed method is
1296 used if the block codes up smaller that way (usually for quite small
1297 chunks), otherwise the dynamic method is used. In the latter case, the
1298 codes are customized to the probabilities in the current block, and so
1299 can code it much better than the pre-determined fixed codes.
1301 The Huffman codes themselves are decoded using a mutli-level table
1302 lookup, in order to maximize the speed of decoding plus the speed of
1303 building the decoding tables. See the comments below that precede the
1304 lbits and dbits tuning parameters.
1309 Notes beyond the 1.93a appnote.txt:
1311 1. Distance pointers never point before the beginning of the output
1313 2. Distance pointers can point back across blocks, up to 32k away.
1314 3. There is an implied maximum of 7 bits for the bit length table and
1315 15 bits for the actual data.
1316 4. If only one code exists, then it is encoded using one bit. (Zero
1317 would be more efficient, but perhaps a little confusing.) If two
1318 codes exist, they are coded using one bit each (0 and 1).
1319 5. There is no way of sending zero distance codes--a dummy must be
1320 sent if there are none. (History: a pre 2.0 version of PKZIP would
1321 store blocks with no distance codes, but this was discovered to be
1322 too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
1323 zero distance codes, which is sent as one code of zero bits in
1325 6. There are up to 286 literal/length codes. Code 256 represents the
1326 end-of-block. Note however that the static length tree defines
1327 288 codes just to fill out the Huffman codes. Codes 286 and 287
1328 cannot be used though, since there is no length base or extra bits
1329 defined for them. Similarly, there are up to 30 distance codes.
1330 However, static trees define 32 codes (all 5 bits) to fill out the
1331 Huffman codes, but the last two had better not show up in the data.
1332 7. Unzip can check dynamic Huffman blocks for complete code sets.
1333 The exception is that a single code would not be complete (see #4).
1334 8. The five bits following the block type is really the number of
1335 literal codes sent minus 257.
1336 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
1337 (1+6+6). Therefore, to output three times the length, you output
1338 three codes (1+1+1), whereas to output four times the same length,
1339 you only need two codes (1+3). Hmm.
1340 10. In the tree reconstruction algorithm, Code = Code + Increment
1341 only if BitLength(i) is not zero. (Pretty obvious.)
1342 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
1343 12. Note: length code 284 can represent 227-258, but length code 285
1344 really is 258. The last length deserves its own, short code
1345 since it gets used a lot in very redundant files. The length
1346 258 is special since 258 - 3 (the min match length) is 255.
1347 13. The literal/length and distance code bit lengths are read as a
1348 single stream of lengths. It is possible (and advantageous) for
1349 a repeat code (16, 17, or 18) to go across the boundary between
1350 the two sets of lengths.
1353 #include <sys/types.h>
1355 #if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
1356 # include <stdlib.h>
1360 #define slide window
1362 /* Huffman code lookup table entry--this entry is four bytes for machines
1363 that have 16-bit pointers (e.g. PC's in the small or medium model).
1364 Valid extra bits are 0..13. e == 15 is EOB (end of block), e == 16
1365 means that v is a literal, 16 < e < 32 means that v is a pointer to
1366 the next table, which codes e - 16 bits, and lastly e == 99 indicates
1367 an unused code. If a code with e == 99 is looked up, this implies an
1368 error in the data. */
1370 uch e; /* number of extra bits or operation */
1371 uch b; /* number of bits in this code or subcode */
1373 ush n; /* literal, length base, or distance base */
1374 struct huft *t; /* pointer to next level of table */
1379 /* Function prototypes */
1380 int huft_build (unsigned *, unsigned, unsigned, ush *, ush *,
1381 struct huft **, int *);
1382 int huft_free (struct huft *);
1383 int inflate_codes (struct huft *, struct huft *, int, int);
1384 int inflate_stored (void);
1385 int inflate_fixed (void);
1386 int inflate_dynamic (void);
1387 int inflate_block (int *);
1391 /* The inflate algorithm uses a sliding 32K byte window on the uncompressed
1392 stream to find repeated byte strings. This is implemented here as a
1393 circular buffer. The index is updated simply by incrementing and then
1394 and'ing with 0x7fff (32K-1). */
1395 /* It is left to other modules to supply the 32K area. It is assumed
1396 to be usable as if it were declared "uch slide[32768];" or as just
1397 "uch *slide;" and then malloc'ed in the latter case. The definition
1398 must be in unzip.h, included above. */
1399 /* unsigned wp; current position in slide */
1401 #define flush_output(w) (wp=(w),flush_window())
1403 /* Tables for deflate from PKZIP's appnote.txt. */
1404 static unsigned border[] = { /* Order of the bit length code lengths */
1405 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
1407 static ush cplens[] = { /* Copy lengths for literal codes 257..285 */
1408 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
1409 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
1412 /* note: see note #13 above about the 258 in this list. */
1413 static ush cplext[] = { /* Extra bits for literal codes 257..285 */
1414 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
1415 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99
1416 }; /* 99==invalid */
1417 static ush cpdist[] = { /* Copy offsets for distance codes 0..29 */
1418 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
1419 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
1420 8193, 12289, 16385, 24577
1422 static ush cpdext[] = { /* Extra bits for distance codes */
1423 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
1424 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
1430 /* Macros for inflate() bit peeking and grabbing.
1434 x = b & mask_bits[j];
1437 where NEEDBITS makes sure that b has at least j bits in it, and
1438 DUMPBITS removes the bits from b. The macros use the variable k
1439 for the number of bits in b. Normally, b and k are register
1440 variables for speed, and are initialized at the beginning of a
1441 routine that uses these macros from a global bit buffer and count.
1443 If we assume that EOB will be the longest code, then we will never
1444 ask for bits with NEEDBITS that are beyond the end of the stream.
1445 So, NEEDBITS should not read any more bytes than are needed to
1446 meet the request. Then no bytes need to be "returned" to the buffer
1447 at the end of the last block.
1449 However, this assumption is not true for fixed blocks--the EOB code
1450 is 7 bits, but the other literal/length codes can be 8 or 9 bits.
1451 (The EOB code is shorter than other codes because fixed blocks are
1452 generally short. So, while a block always has an EOB, many other
1453 literal/length codes have a significantly lower probability of
1454 showing up at all.) However, by making the first table have a
1455 lookup of seven bits, the EOB code will be found in that first
1456 lookup, and so will not require that too many bits be pulled from
1460 ulg bb; /* bit buffer */
1461 unsigned bk; /* bits in bit buffer */
1465 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
1466 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
1472 # define NEXTBYTE() (cc = get_byte(), zdecode(cc), cc)
1474 # define NEXTBYTE() (uch)get_byte()
1476 #define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE())<<k;k+=8;}}
1477 #define DUMPBITS(n) {b>>=(n);k-=(n);}
1481 Huffman code decoding is performed using a multi-level table lookup.
1482 The fastest way to decode is to simply build a lookup table whose
1483 size is determined by the longest code. However, the time it takes
1484 to build this table can also be a factor if the data being decoded
1485 is not very long. The most common codes are necessarily the
1486 shortest codes, so those codes dominate the decoding time, and hence
1487 the speed. The idea is you can have a shorter table that decodes the
1488 shorter, more probable codes, and then point to subsidiary tables for
1489 the longer codes. The time it costs to decode the longer codes is
1490 then traded against the time it takes to make longer tables.
1492 This results of this trade are in the variables lbits and dbits
1493 below. lbits is the number of bits the first level table for literal/
1494 length codes can decode in one step, and dbits is the same thing for
1495 the distance codes. Subsequent tables are also less than or equal to
1496 those sizes. These values may be adjusted either when all of the
1497 codes are shorter than that, in which case the longest code length in
1498 bits is used, or when the shortest code is *longer* than the requested
1499 table size, in which case the length of the shortest code in bits is
1502 There are two different values for the two tables, since they code a
1503 different number of possibilities each. The literal/length table
1504 codes 286 possible values, or in a flat code, a little over eight
1505 bits. The distance table codes 30 possible values, or a little less
1506 than five bits, flat. The optimum values for speed end up being
1507 about one bit more than those, so lbits is 8+1 and dbits is 5+1.
1508 The optimum values may differ though from machine to machine, and
1509 possibly even between compilers. Your mileage may vary.
1513 int lbits = 9; /* bits in base literal/length lookup table */
1514 int dbits = 6; /* bits in base distance lookup table */
1517 /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
1518 #define BMAX 16 /* maximum bit length of any code (16 for explode) */
1519 #define N_MAX 288 /* maximum number of codes in any set */
1522 unsigned hufts; /* track memory usage */
1525 int huft_build(b, n, s, d, e, t, m)
1526 unsigned *b; /* code lengths in bits (all assumed <= BMAX) */
1527 unsigned n; /* number of codes (assumed <= N_MAX) */
1528 unsigned s; /* number of simple-valued codes (0..s-1) */
1529 ush *d; /* list of base values for non-simple codes */
1530 ush *e; /* list of extra bits for non-simple codes */
1531 struct huft **t; /* result: starting table */
1532 int *m; /* maximum lookup bits, returns actual */
1534 /* Given a list of code lengths and a maximum table size, make a set of
1535 tables to decode that set of codes. Return zero on success, one if
1536 the given code set is incomplete (the tables are still built in this
1537 case), two if the input is invalid (all zero length codes or an
1538 oversubscribed set of lengths), and three if not enough memory. */
1540 unsigned a; /* counter for codes of length k */
1541 unsigned c[BMAX + 1]; /* bit length count table */
1542 unsigned f; /* i repeats in table every f entries */
1543 int g; /* maximum code length */
1544 int h; /* table level */
1545 register unsigned i; /* counter, current code */
1546 register unsigned j; /* counter */
1547 register int k; /* number of bits in current code */
1548 int l; /* bits per table (returned in m) */
1549 register unsigned *p; /* pointer into c[], b[], or v[] */
1550 register struct huft *q; /* points to current table */
1551 struct huft r; /* table entry for structure assignment */
1552 struct huft *u[BMAX]; /* table stack */
1553 unsigned v[N_MAX]; /* values in order of bit length */
1554 register int w; /* bits before this table == (l * h) */
1555 unsigned x[BMAX + 1]; /* bit offsets, then code stack */
1556 unsigned *xp; /* pointer into x */
1557 int y; /* number of dummy codes added */
1558 unsigned z; /* number of entries in current table */
1561 /* Generate counts for each bit length */
1562 memzero(c, sizeof(c));
1569 && n - i <= '~' ? "%c %d\n" : "0x%x %d\n"), n - i, *p));
1570 c[*p]++; /* assume all entries <= BMAX */
1571 p++; /* Can't combine with above line (Solaris bug) */
1573 if (c[0] == n) { /* null input--all zero length codes */
1574 *t = (struct huft *) NULL;
1580 /* Find minimum and maximum length, bound *m by those */
1582 for (j = 1; j <= BMAX; j++)
1585 k = j; /* minimum code length */
1586 if ((unsigned) l < j)
1588 for (i = BMAX; i; i--)
1591 g = i; /* maximum code length */
1592 if ((unsigned) l > i)
1597 /* Adjust last length count to fill out codes, if needed */
1598 for (y = 1 << j; j < i; j++, y <<= 1)
1599 if ((y -= c[j]) < 0)
1600 return 2; /* bad input: more codes than bits */
1601 if ((y -= c[i]) < 0)
1606 /* Generate starting offsets into the value table for each length */
1610 while (--i) { /* note that i == g from above */
1611 *xp++ = (j += *p++);
1615 /* Make a table of values in order of bit lengths */
1619 if ((j = *p++) != 0)
1624 /* Generate the Huffman codes and for each, make the table entries */
1625 x[0] = i = 0; /* first Huffman code is zero */
1626 p = v; /* grab values in bit order */
1627 h = -1; /* no tables yet--level -1 */
1628 w = -l; /* bits decoded == (l * h) */
1629 u[0] = (struct huft *) NULL; /* just to keep compilers happy */
1630 q = (struct huft *) NULL; /* ditto */
1633 /* go through the bit lengths (k already is bits in shortest code) */
1634 for (; k <= g; k++) {
1637 /* here i is the Huffman code of length k bits for value *p */
1638 /* make tables up to required level */
1641 w += l; /* previous table always l bits */
1643 /* compute minimum size table less than or equal to l bits */
1644 z = (z = g - w) > (unsigned) l ? l : z; /* upper limit on table size */
1645 if ((f = 1 << (j = k - w)) > a + 1) { /* try a k-w bit table *//* too few codes for k-w bit table */
1646 f -= a + 1; /* deduct codes from patterns left */
1648 while (++j < z) { /* try smaller tables up to z bits */
1649 if ((f <<= 1) <= *++xp)
1650 break; /* enough codes to use up j bits */
1651 f -= *xp; /* else deduct codes from patterns */
1654 z = 1 << j; /* table entries for j-bit table */
1656 /* allocate and link in new table */
1659 (struct huft *) malloc((z + 1) *
1660 sizeof(struct huft))) ==
1661 (struct huft *) NULL) {
1664 return 3; /* not enough memory */
1666 hufts += z + 1; /* track memory usage */
1667 *t = q + 1; /* link to list for huft_free() */
1668 *(t = &(q->v.t)) = (struct huft *) NULL;
1669 u[h] = ++q; /* table starts after link */
1671 /* connect to last table, if there is one */
1673 x[h] = i; /* save pattern for backing up */
1674 r.b = (uch) l; /* bits to dump before this table */
1675 r.e = (uch) (16 + j); /* bits in this table */
1676 r.v.t = q; /* pointer to this table */
1677 j = i >> (w - l); /* (get around Turbo C bug) */
1678 u[h - 1][j] = r; /* connect to last table */
1682 /* set up table entry in r */
1683 r.b = (uch) (k - w);
1685 r.e = 99; /* out of values--invalid code */
1687 r.e = (uch) (*p < 256 ? 16 : 15); /* 256 is end-of-block code */
1688 r.v.n = (ush) (*p); /* simple code is just the value */
1689 p++; /* one compiler does not like *p++ */
1691 r.e = (uch) e[*p - s]; /* non-simple--look up in lists */
1692 r.v.n = d[*p++ - s];
1695 /* fill code-like entries with r */
1697 for (j = i >> w; j < z; j += f)
1700 /* backwards increment the k-bit code i */
1701 for (j = 1 << (k - 1); i & j; j >>= 1)
1705 /* backup over finished tables */
1706 while ((i & ((1 << w) - 1)) != x[h]) {
1707 h--; /* don't need to update q */
1714 /* Return true (1) if we were given an incomplete table */
1715 return y != 0 && g != 1;
1721 struct huft *t; /* table to free */
1723 /* Free the malloc'ed tables built by huft_build(), which makes a linked
1724 list of the tables it made, with the links in a dummy first entry of
1727 register struct huft *p, *q;
1730 /* Go through linked list, freeing from the malloced (t[-1]) address. */
1732 while (p != (struct huft *) NULL) {
1741 int inflate_codes(tl, td, bl, bd)
1742 struct huft *tl, *td; /* literal/length and distance decoder tables */
1743 int bl, bd; /* number of bits decoded by tl[] and td[] */
1745 /* inflate (decompress) the codes in a deflated (compressed) block.
1746 Return an error code or zero if it all goes ok. */
1748 register unsigned e; /* table entry flag/number of extra bits */
1749 unsigned n, d; /* length and index for copy */
1750 unsigned w; /* current window position */
1751 struct huft *t; /* pointer to table entry */
1752 unsigned ml, md; /* masks for bl and bd bits */
1753 register ulg b; /* bit buffer */
1754 register unsigned k; /* number of bits in bit buffer */
1757 /* make local copies of globals */
1758 b = bb; /* initialize bit buffer */
1760 w = wp; /* initialize window position */
1762 /* inflate the coded data */
1763 ml = mask_bits[bl]; /* precompute masks for speed */
1765 for (;;) { /* do until end of block */
1766 NEEDBITS((unsigned) bl)
1767 if ((e = (t = tl + ((unsigned) b & ml))->e) > 16)
1774 } while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e)
1777 if (e == 16) { /* then it's a literal */
1778 slide[w++] = (uch) t->v.n;
1779 Tracevv((stderr, "%c", slide[w - 1]));
1784 } else { /* it's an EOB or a length */
1786 /* exit if end of block */
1790 /* get length of block to copy */
1792 n = t->v.n + ((unsigned) b & mask_bits[e]);
1795 /* decode distance of block to copy */
1796 NEEDBITS((unsigned) bd)
1797 if ((e = (t = td + ((unsigned) b & md))->e) > 16)
1808 t->v.t + ((unsigned) b & mask_bits[e]))->e) >
1812 d = w - t->v.n - ((unsigned) b & mask_bits[e]);
1814 Tracevv((stderr, "\\[%d,%d]", w - d, n));
1820 WSIZE - ((d &= WSIZE - 1) > w ? d : w)) >
1822 #if !defined(NOMEMCPY) && !defined(DEBUG)
1823 if (w - d >= e) { /* (this test assumes unsigned comparison) */
1824 memcpy(slide + w, slide + d, e);
1827 } else /* do it slow to avoid memcpy() overlap */
1828 #endif /* !NOMEMCPY */
1830 slide[w++] = slide[d++];
1831 Tracevv((stderr, "%c", slide[w - 1]));
1842 /* restore the globals from the locals */
1843 wp = w; /* restore global window pointer */
1844 bb = b; /* restore global bit buffer */
1853 int inflate_stored()
1854 /* "decompress" an inflated type 0 (stored) block. */
1856 unsigned n; /* number of bytes in block */
1857 unsigned w; /* current window position */
1858 register ulg b; /* bit buffer */
1859 register unsigned k; /* number of bits in bit buffer */
1862 /* make local copies of globals */
1863 b = bb; /* initialize bit buffer */
1865 w = wp; /* initialize window position */
1868 /* go to byte boundary */
1873 /* get the length and its complement */
1875 n = ((unsigned) b & 0xffff);
1878 if (n != (unsigned) ((~b) & 0xffff))
1879 return 1; /* error in compressed data */
1883 /* read and output the compressed data */
1886 slide[w++] = (uch) b;
1895 /* restore the globals from the locals */
1896 wp = w; /* restore global window pointer */
1897 bb = b; /* restore global bit buffer */
1905 /* decompress an inflated type 1 (fixed Huffman codes) block. We should
1906 either replace this with a custom decoder, or at least precompute the
1909 int i; /* temporary variable */
1910 struct huft *tl; /* literal/length code table */
1911 struct huft *td; /* distance code table */
1912 int bl; /* lookup bits for tl */
1913 int bd; /* lookup bits for td */
1914 unsigned l[288]; /* length list for huft_build */
1917 /* set up literal table */
1918 for (i = 0; i < 144; i++)
1920 for (; i < 256; i++)
1922 for (; i < 280; i++)
1924 for (; i < 288; i++) /* make a complete, but wrong code set */
1927 if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0)
1931 /* set up distance table */
1932 for (i = 0; i < 30; i++) /* make an incomplete code set */
1935 if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1) {
1941 /* decompress until an end-of-block code */
1942 if (inflate_codes(tl, td, bl, bd))
1946 /* free the decoding tables, return */
1954 int inflate_dynamic()
1955 /* decompress an inflated type 2 (dynamic Huffman codes) block. */
1957 int i; /* temporary variables */
1959 unsigned l; /* last length */
1960 unsigned m; /* mask for bit lengths table */
1961 unsigned n; /* number of lengths to get */
1962 struct huft *tl; /* literal/length code table */
1963 struct huft *td; /* distance code table */
1964 int bl; /* lookup bits for tl */
1965 int bd; /* lookup bits for td */
1966 unsigned nb; /* number of bit length codes */
1967 unsigned nl; /* number of literal/length codes */
1968 unsigned nd; /* number of distance codes */
1970 #ifdef PKZIP_BUG_WORKAROUND
1971 unsigned ll[288 + 32]; /* literal/length and distance code lengths */
1973 unsigned ll[286 + 30]; /* literal/length and distance code lengths */
1975 register ulg b; /* bit buffer */
1976 register unsigned k; /* number of bits in bit buffer */
1979 /* make local bit buffer */
1984 /* read in table lengths */
1986 nl = 257 + ((unsigned) b & 0x1f); /* number of literal/length codes */
1989 nd = 1 + ((unsigned) b & 0x1f); /* number of distance codes */
1992 nb = 4 + ((unsigned) b & 0xf); /* number of bit length codes */
1994 #ifdef PKZIP_BUG_WORKAROUND
1995 if (nl > 288 || nd > 32)
1997 if (nl > 286 || nd > 30)
1999 return 1; /* bad lengths */
2002 /* read in bit-length-code lengths */
2003 for (j = 0; j < nb; j++) {
2005 ll[border[j]] = (unsigned) b & 7;
2012 /* build decoding table for trees--single level, 7 bit lookup */
2014 if ((i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl)) != 0) {
2017 return i; /* incomplete code set */
2021 /* read in literal and distance code lengths */
2025 while ((unsigned) i < n) {
2026 NEEDBITS((unsigned) bl)
2027 j = (td = tl + ((unsigned) b & m))->b;
2030 if (j < 16) /* length of code in bits (0..15) */
2031 ll[i++] = l = j; /* save last length in l */
2032 else if (j == 16) { /* repeat last length 3 to 6 times */
2034 j = 3 + ((unsigned) b & 3);
2036 if ((unsigned) i + j > n)
2040 } else if (j == 17) { /* 3 to 10 zero length codes */
2042 j = 3 + ((unsigned) b & 7);
2044 if ((unsigned) i + j > n)
2049 } else { /* j == 18: 11 to 138 zero length codes */
2052 j = 11 + ((unsigned) b & 0x7f);
2054 if ((unsigned) i + j > n)
2063 /* free decoding table for trees */
2067 /* restore the global bit buffer */
2072 /* build the decoding tables for literal/length and distance codes */
2074 if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0) {
2076 fprintf(stderr, " incomplete literal tree\n");
2079 return i; /* incomplete code set */
2082 if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0) {
2084 fprintf(stderr, " incomplete distance tree\n");
2085 #ifdef PKZIP_BUG_WORKAROUND
2092 return i; /* incomplete code set */
2097 /* decompress until an end-of-block code */
2098 if (inflate_codes(tl, td, bl, bd))
2102 /* free the decoding tables, return */
2110 int inflate_block(e)
2111 int *e; /* last block flag */
2113 /* decompress an inflated block */
2115 unsigned t; /* block type */
2116 register ulg b; /* bit buffer */
2117 register unsigned k; /* number of bits in bit buffer */
2120 /* make local bit buffer */
2125 /* read in last block bit */
2131 /* read in block type */
2133 t = (unsigned) b & 3;
2137 /* restore the global bit buffer */
2142 /* inflate that block type */
2144 return inflate_dynamic();
2146 return inflate_stored();
2148 return inflate_fixed();
2151 /* bad block type */
2158 /* decompress an inflated entry */
2160 int e; /* last block flag */
2161 int r; /* result code */
2162 unsigned h; /* maximum struct huft's malloc'ed */
2165 /* initialize window, bit buffer */
2171 /* decompress until the last block */
2175 if ((r = inflate_block(&e)) != 0)
2181 /* Undo too much lookahead. The next read will be byte aligned so we
2182 * can discard unused bits in the last meaningful byte.
2189 /* flush out slide */
2193 /* return success */
2195 fprintf(stderr, "<%u> ", h);