gzip.h

   1 /* gzip.h -- common declarations for all gzip modules
   2
   3    Copyright (C) 1997-1999, 2001, 2006-2007, 2009-2024 Free Software
   4    Foundation, Inc.
   5
   6    Copyright (C) 1992-1993 Jean-loup Gailly.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3, or (at your option)
  11    any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  20
  21 #ifdef __STDC__
  22    typedef void *voidp;
  23 #else
  24    typedef char *voidp;
  25 #endif
  26
  27 #ifndef __attribute__
  28 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
  29 #  define __attribute__(x)
  30 # endif
  31 #endif
  32
  33 /* I don't like nested includes, but the following headers are used
  34  * too often
  35  */
  36 #include <stdio.h>
  37 #include <sys/types.h> /* for off_t */
  38 #include <time.h>
  39 #include <string.h>
  40 #define memzero(s, n) memset ((voidp)(s), 0, (n))
  41
  42 typedef unsigned char  uch;
  43 typedef unsigned short ush;
  44 typedef unsigned long  ulg;
  45
  46 /* Return codes from gzip */
  47 #define OK      0
  48 #define ERROR   1
  49 #define WARNING 2
  50
  51 /* Compression methods (see algorithm.doc) */
  52 #define STORED      0
  53 #define COMPRESSED  1
  54 #define PACKED      2
  55 #define LZHED       3
  56 /* methods 4 to 7 reserved */
  57 #define DEFLATED    8
  58 #define MAX_METHODS 9
  59 extern int method;         /* compression method */
  60
  61 /* To save memory for 16 bit systems, some arrays are overlaid between
  62  * the various modules:
  63  * deflate:  prev+head   window      d_buf  l_buf  outbuf
  64  * unlzw:    tab_prefix  tab_suffix  stack  inbuf  outbuf
  65  * inflate:              window             inbuf
  66  * unpack:               window             inbuf  prefix_len
  67  * unlzh:    left+right  window      c_table inbuf c_len
  68  * For compression, input is done in window[]. For decompression, output
  69  * is done in window except for unlzw.
  70  */
  71
  72 #ifndef INBUFSIZ
  73 #  ifdef SMALL_MEM
  74 #    define INBUFSIZ  0x2000  /* input buffer size */
  75 #  else
  76 #    define INBUFSIZ  0x40000 /* input buffer size */
  77 #  endif
  78 #endif
  79 #define INBUF_EXTRA  64     /* required by unlzw() */
  80
  81 #ifndef OUTBUFSIZ
  82 #  ifdef SMALL_MEM
  83 #    define OUTBUFSIZ   8192  /* output buffer size */
  84 #  else
  85 #    define OUTBUFSIZ 0x40000 /* output buffer size */
  86 #  endif
  87 #endif
  88 #define OUTBUF_EXTRA 2048   /* required by unlzw() */
  89
  90 #ifndef DIST_BUFSIZE
  91 #  ifdef SMALL_MEM
  92 #    define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */
  93 #  else
  94 #    define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */
  95 #  endif
  96 #endif
  97
  98 #ifdef DYN_ALLOC
  99 #  define EXTERN(type, array)  extern type * near array
 100 #  define DECLARE(type, array, size)  type * near array
 101 #  define ALLOC(type, array, size) { \
 102       array = (type*)fcalloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \
 103       if (!array) xalloc_die (); \
 104    }
 105 #  define FREE(array) {if (array != NULL) fcfree(array), array=NULL;}
 106 #else
 107 #  define EXTERN(type, array)  extern type array[]
 108 #  define DECLARE(type, array, size)  type array[size]
 109 #  define ALLOC(type, array, size)
 110 #  define FREE(array)
 111 #endif
 112
 113 EXTERN(uch, inbuf);          /* input buffer */
 114 EXTERN(uch, outbuf);         /* output buffer */
 115 EXTERN(ush, d_buf);          /* buffer for distances, see trees.c */
 116 EXTERN(uch, window);         /* Sliding window and suffix table (unlzw) */
 117 #define tab_suffix window
 118 #ifndef MAXSEG_64K
 119 #  define tab_prefix prev    /* hash link (see deflate.c) */
 120 #  define head (prev+WSIZE)  /* hash head (see deflate.c) */
 121    EXTERN(ush, tab_prefix);  /* prefix code (see unlzw.c) */
 122 #else
 123 #  define tab_prefix0 prev
 124 #  define head tab_prefix1
 125    EXTERN(ush, tab_prefix0); /* prefix for even codes */
 126    EXTERN(ush, tab_prefix1); /* prefix for odd  codes */
 127 #endif
 128
 129 extern unsigned insize; /* valid bytes in inbuf */
 130 extern unsigned inptr;  /* index of next byte to be processed in inbuf */
 131 extern unsigned outcnt; /* bytes in output buffer */
 132 extern int rsync;  /* deflate into rsyncable chunks */
 133
 134 extern off_t bytes_in;   /* number of input bytes */
 135 extern off_t bytes_out;  /* number of output bytes */
 136 extern off_t header_bytes;/* number of bytes in gzip header */
 137
 138 extern int  ifd;        /* input file descriptor */
 139 extern int  ofd;        /* output file descriptor */
 140 extern char ifname[];   /* input file name or "stdin" */
 141 extern char ofname[];   /* output file name or "stdout" */
 142 extern char *program_name;  /* program name */
 143
 144 extern struct timespec time_stamp; /* original timestamp (modification time) */
 145 extern off_t ifile_size; /* input file size, -1 for devices (debug only) */
 146
 147 typedef int file_t;     /* Do not use stdio */
 148 #define NO_FILE  (-1)   /* in memory compression */
 149
 150
 151 #define PACK_MAGIC     "\037\036" /* Magic header for packed files */
 152 #define GZIP_MAGIC     "\037\213" /* Magic header for gzip files, 1F 8B */
 153 #define OLD_GZIP_MAGIC "\037\236" /* Magic header for gzip 0.5 = freeze 1.x */
 154 #define LZH_MAGIC      "\037\240" /* Magic header for SCO LZH Compress files*/
 155 #define PKZIP_MAGIC    "\120\113\003\004" /* Magic header for pkzip files */
 156
 157 /* gzip flag byte */
 158 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
 159 #define HEADER_CRC   0x02 /* bit 1 set: CRC16 for the gzip header */
 160 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 161 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 162 #define COMMENT      0x10 /* bit 4 set: file comment present */
 163 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 164 #define RESERVED     0xC0 /* bit 6,7:   reserved */
 165
 166 /* internal file attribute */
 167 #define UNKNOWN 0xffff
 168 #define BINARY  0
 169 #define ASCII   1
 170
 171 #ifndef WSIZE
 172 #  define WSIZE 0x8000     /* window size--must be a power of two, and */
 173 #endif                     /*  at least 32K for zip's deflate method */
 174
 175 #define MIN_MATCH  3
 176 #define MAX_MATCH  258
 177 /* The minimum and maximum match lengths */
 178
 179 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
 180 /* Minimum amount of lookahead, except at the end of the input file.
 181  * See deflate.c for comments about the MIN_MATCH+1.
 182  */
 183
 184 #define MAX_DIST  (WSIZE-MIN_LOOKAHEAD)
 185 /* In order to simplify the code, particularly on 16 bit machines, match
 186  * distances are limited to MAX_DIST instead of WSIZE.
 187  */
 188
 189 extern int exit_code;      /* program exit code */
 190 extern int quiet;          /* be quiet (-q) */
 191 extern int level;          /* compression level */
 192 extern int test;           /* check .z file integrity */
 193 extern int to_stdout;      /* output to stdout (-c) */
 194 extern int save_orig_name; /* set if original name must be saved */
 195
 196 #define get_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf(0))
 197 #define try_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf(1))
 198
 199 /* put_byte is used for the compressed output, put_ubyte for the
 200  * uncompressed output. However unlzw() uses window for its
 201  * suffix table instead of its output buffer, so it does not use put_ubyte
 202  * (to be cleaned up).
 203  */
 204 #define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
 205    flush_outbuf();}
 206 #define put_ubyte(c) {window[outcnt++]=(uch)(c); if (outcnt==WSIZE)\
 207    flush_window();}
 208
 209 /* Output a 16 bit value, lsb first */
 210 #define put_short(w) \
 211 { if (outcnt < OUTBUFSIZ-2) { \
 212     outbuf[outcnt++] = (uch) ((w) & 0xff); \
 213     outbuf[outcnt++] = (uch) ((ush)(w) >> 8); \
 214   } else { \
 215     put_byte((uch)((w) & 0xff)); \
 216     put_byte((uch)((ush)(w) >> 8)); \
 217   } \
 218 }
 219
 220 /* Output a 32 bit value to the bit stream, lsb first */
 221 #define put_long(n) { \
 222     put_short((n) & 0xffff); \
 223     put_short(((ulg)(n)) >> 16); \
 224 }
 225
 226 #define seekable()    0  /* force sequential output */
 227 #define translate_eol 0  /* no option -a yet */
 228
 229 #define tolow(c)  (isupper (c) ? tolower (c) : (c))  /* force to lower case */
 230
 231 /* Macros for getting two-byte and four-byte header values */
 232 #define SH(p) ((ush)(uch)((p)[0]) | ((ush)(uch)((p)[1]) << 8))
 233 #define LG(p) ((ulg)(SH(p)) | ((ulg)(SH((p)+2)) << 16))
 234
 235 /* Diagnostic functions */
 236 #ifdef DEBUG
 237 extern int verbose;        /* be verbose (-v) */
 238 #  define Assert(cond,msg) {if (!(cond)) gzip_error (msg);}
 239 #  define Trace(x) fprintf x
 240 #  define Tracev(x) {if (verbose) fprintf x ;}
 241 #  define Tracevv(x) {if (verbose>1) fprintf x ;}
 242 #  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
 243 #  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
 244 #else
 245 #  define Assert(cond,msg)
 246 #  define Trace(x)
 247 #  define Tracev(x)
 248 #  define Tracevv(x)
 249 #  define Tracec(c,x)
 250 #  define Tracecv(c,x)
 251 #endif
 252
 253 #define WARN(msg) \
 254   do \
 255     { \
 256       if (!quiet) \
 257         fprintf msg; \
 258       if (exit_code == OK) \
 259         exit_code = WARNING; \
 260     } \
 261   while (false)
 262
 263         /* in zip.c: */
 264 extern int zip        (int in, int out);
 265 extern int file_read  (char *buf,  unsigned size);
 266
 267         /* in unzip.c */
 268 extern ulg unzip_crc;
 269 extern int unzip      (int in, int out);
 270 extern int check_zipfile (int in);
 271
 272         /* in unpack.c */
 273 extern int unpack     (int in, int out);
 274
 275         /* in unlzh.c */
 276 extern int unlzh      (int in, int out);
 277
 278         /* in gzip.c */
 279 _Noreturn extern void finish_up_gzip (int);
 280 _Noreturn extern void abort_gzip (void);
 281
 282         /* in deflate.c */
 283 extern off_t gzip_deflate (int pack_level);
 284
 285         /* in trees.c */
 286 extern void ct_init     (ush *attr, int *method);
 287 extern int  ct_tally    (int dist, int lc);
 288 extern off_t flush_block (char *buf, ulg stored_len, int pad, int eof);
 289
 290         /* in bits.c */
 291 #ifdef IBM_Z_DFLTCC
 292 extern unsigned short bi_buf;
 293 extern int bi_valid;
 294 #endif
 295 extern void     bi_init    (file_t zipfile);
 296 extern void     send_bits  (int value, int length);
 297 extern unsigned bi_reverse (unsigned value, int length) _GL_ATTRIBUTE_CONST;
 298 extern void     bi_windup  (void);
 299 extern void     copy_block (char *buf, unsigned len, int header);
 300 extern int     (*read_buf) (char *buf, unsigned size);
 301
 302         /* in util.c: */
 303 extern int copy           (int in, int out);
 304 extern ulg  updcrc        (const uch *s, unsigned n);
 305 extern ulg  getcrc        (void) _GL_ATTRIBUTE_PURE;
 306 extern void setcrc        (ulg c);
 307 extern void clear_bufs    (void);
 308 extern int  fill_inbuf    (int eof_ok);
 309 extern void flush_outbuf  (void);
 310 extern void flush_window  (void);
 311 extern void write_buf     (int fd, voidp buf, unsigned cnt);
 312 extern int read_buffer    (int fd, voidp buf, unsigned int cnt);
 313 extern char *strlwr       (char *s);
 314 extern char *gzip_base_name (char *fname) _GL_ATTRIBUTE_PURE;
 315 extern int xunlink        (char *fname);
 316 extern void make_simple_name (char *name);
 317 extern char *add_envopt   (int *argcp, char ***argvp, char const *env);
 318 _Noreturn extern void gzip_error (char const *m);
 319 _Noreturn extern void xalloc_die (void);
 320 extern void warning       (char const *m);
 321 _Noreturn extern void read_error (void);
 322 _Noreturn extern void write_error (void);
 323 extern void display_ratio (off_t num, off_t den, FILE *file);
 324
 325         /* in inflate.c */
 326 extern int gzip_inflate (void);
 327
 328         /* in dfltcc.c */
 329 #ifdef IBM_Z_DFLTCC
 330 extern int dfltcc_deflate (int pack_level);
 331 extern int dfltcc_inflate (void);
 332 #endif