util.c

   1 /* util.c -- utility functions for gzip support
   2
   3    Copyright (C) 1997-1999, 2001-2002, 2006, 2009-2016 Free Software
   4    Foundation, Inc.
   5    Copyright (C) 1992-1993 Jean-loup Gailly
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3, or (at your option)
  10    any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software Foundation,
  19    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  20
  21 #include <config.h>
  22 #include <ctype.h>
  23 #include <errno.h>
  24
  25 #include "tailor.h"
  26
  27 #include <limits.h>
  28 #include <unistd.h>
  29 #include <fcntl.h>
  30 #include <stdlib.h>
  31 #include <errno.h>
  32
  33 #include "gzip.h"
  34 #include <xalloc.h>
  35
  36 #ifndef CHAR_BIT
  37 #  define CHAR_BIT 8
  38 #endif
  39
  40 static int write_buffer (int, voidp, unsigned int);
  41
  42 /* ========================================================================
  43  * Table of CRC-32's of all single-byte values (made by makecrc.c)
  44  */
  45 static const ulg crc_32_tab[] = {
  46   0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
  47   0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
  48   0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
  49   0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
  50   0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
  51   0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
  52   0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
  53   0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
  54   0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
  55   0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
  56   0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
  57   0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
  58   0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
  59   0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
  60   0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
  61   0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
  62   0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
  63   0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
  64   0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
  65   0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
  66   0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
  67   0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
  68   0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
  69   0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
  70   0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
  71   0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
  72   0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
  73   0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
  74   0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
  75   0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
  76   0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
  77   0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
  78   0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
  79   0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
  80   0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
  81   0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
  82   0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
  83   0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
  84   0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
  85   0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
  86   0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
  87   0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
  88   0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
  89   0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
  90   0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
  91   0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
  92   0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
  93   0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
  94   0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
  95   0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
  96   0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
  97   0x2d02ef8dL
  98 };
  99
 100 /* ===========================================================================
 101  * Copy input to output unchanged: zcat == cat with --force.
 102  * IN assertion: insize bytes have already been read in inbuf and inptr bytes
 103  * already processed or copied.
 104  */
 105 int copy(in, out)
 106     int in, out;   /* input and output file descriptors */
 107 {
 108     int got;
 109
 110     errno = 0;
 111     while (insize > inptr) {
 112         write_buf(out, (char*)inbuf + inptr, insize - inptr);
 113         bytes_out += insize - inptr;
 114         got = read_buffer (in, (char *) inbuf, INBUFSIZ);
 115         if (got == -1)
 116             read_error();
 117         bytes_in += got;
 118         insize = (unsigned)got;
 119         inptr = 0;
 120     }
 121     return OK;
 122 }
 123
 124 /* ===========================================================================
 125  * Run a set of bytes through the crc shift register.  If s is a NULL
 126  * pointer, then initialize the crc shift register contents instead.
 127  * Return the current crc in either case.
 128  */
 129 ulg updcrc(s, n)
 130     uch *s;                 /* pointer to bytes to pump through */
 131     unsigned n;             /* number of bytes in s[] */
 132 {
 133     register ulg c;         /* temporary variable */
 134
 135     static ulg crc = (ulg)0xffffffffL; /* shift register contents */
 136
 137     if (s == NULL) {
 138         c = 0xffffffffL;
 139     } else {
 140         c = crc;
 141         if (n) do {
 142             c = crc_32_tab[((int)c ^ (*s++)) & 0xff] ^ (c >> 8);
 143         } while (--n);
 144     }
 145     crc = c;
 146     return c ^ 0xffffffffL;       /* (instead of ~c for 64-bit machines) */
 147 }
 148
 149 /* ===========================================================================
 150  * Clear input and output buffers
 151  */
 152 void clear_bufs()
 153 {
 154     outcnt = 0;
 155     insize = inptr = 0;
 156     bytes_in = bytes_out = 0L;
 157 }
 158
 159 /* ===========================================================================
 160  * Fill the input buffer. This is called only when the buffer is empty.
 161  */
 162 int fill_inbuf(eof_ok)
 163     int eof_ok;          /* set if EOF acceptable as a result */
 164 {
 165     int len;
 166
 167     /* Read as much as possible */
 168     insize = 0;
 169     do {
 170         len = read_buffer (ifd, (char *) inbuf + insize, INBUFSIZ - insize);
 171         if (len == 0) break;
 172         if (len == -1) {
 173           read_error();
 174           break;
 175         }
 176         insize += len;
 177     } while (insize < INBUFSIZ);
 178
 179     if (insize == 0) {
 180         if (eof_ok) return EOF;
 181         flush_window();
 182         errno = 0;
 183         read_error();
 184     }
 185     bytes_in += (off_t)insize;
 186     inptr = 1;
 187     return inbuf[0];
 188 }
 189
 190 /* Like the standard read function, except do not attempt to read more
 191    than INT_MAX bytes at a time.  */
 192 int
 193 read_buffer (fd, buf, cnt)
 194      int fd;
 195      voidp buf;
 196      unsigned int cnt;
 197 {
 198   int len;
 199   if (INT_MAX < cnt)
 200     cnt = INT_MAX;
 201   len = read (fd, buf, cnt);
 202
 203 #if defined F_SETFL && O_NONBLOCK && defined EAGAIN
 204   /* Input files are opened O_NONBLOCK for security reasons.  On some
 205      file systems this can cause read to fail with errno == EAGAIN.  */
 206   if (len < 0 && errno == EAGAIN)
 207     {
 208       int flags = fcntl (fd, F_GETFL);
 209       if (0 <= flags)
 210         {
 211           if (! (flags & O_NONBLOCK))
 212             errno = EAGAIN;
 213           else if (fcntl (fd, F_SETFL, flags & ~O_NONBLOCK) != -1)
 214             len = read (fd, buf, cnt);
 215         }
 216     }
 217 #endif
 218
 219   return len;
 220 }
 221
 222 /* Likewise for 'write'.  */
 223 static int
 224 write_buffer (fd, buf, cnt)
 225      int fd;
 226      voidp buf;
 227      unsigned int cnt;
 228 {
 229   if (INT_MAX < cnt)
 230     cnt = INT_MAX;
 231   return write (fd, buf, cnt);
 232 }
 233
 234 /* ===========================================================================
 235  * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
 236  * (used for the compressed data only)
 237  */
 238 void flush_outbuf()
 239 {
 240     if (outcnt == 0) return;
 241
 242     write_buf(ofd, (char *)outbuf, outcnt);
 243     bytes_out += (off_t)outcnt;
 244     outcnt = 0;
 245 }
 246
 247 /* ===========================================================================
 248  * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 249  * (Used for the decompressed data only.)
 250  */
 251 void flush_window()
 252 {
 253     if (outcnt == 0) return;
 254     updcrc(window, outcnt);
 255
 256     if (!test) {
 257         write_buf(ofd, (char *)window, outcnt);
 258     }
 259     bytes_out += (off_t)outcnt;
 260     outcnt = 0;
 261 }
 262
 263 /* ===========================================================================
 264  * Does the same as write(), but also handles partial pipe writes and checks
 265  * for error return.
 266  */
 267 void write_buf(fd, buf, cnt)
 268     int       fd;
 269     voidp     buf;
 270     unsigned  cnt;
 271 {
 272     unsigned  n;
 273
 274     while ((n = write_buffer (fd, buf, cnt)) != cnt) {
 275         if (n == (unsigned)(-1)) {
 276             write_error();
 277         }
 278         cnt -= n;
 279         buf = (voidp)((char*)buf+n);
 280     }
 281 }
 282
 283 /* ========================================================================
 284  * Put string s in lower case, return s.
 285  */
 286 char *strlwr(s)
 287     char *s;
 288 {
 289     char *t;
 290     for (t = s; *t; t++)
 291       *t = tolow ((unsigned char) *t);
 292     return s;
 293 }
 294
 295 /* ========================================================================
 296  * Return the base name of a file (remove any directory prefix and
 297  * any version suffix). For systems with file names that are not
 298  * case sensitive, force the base name to lower case.
 299  */
 300 char *
 301 gzip_base_name (fname)
 302     char *fname;
 303 {
 304     char *p;
 305
 306     if ((p = strrchr(fname, PATH_SEP))  != NULL) fname = p+1;
 307 #ifdef PATH_SEP2
 308     if ((p = strrchr(fname, PATH_SEP2)) != NULL) fname = p+1;
 309 #endif
 310 #ifdef PATH_SEP3
 311     if ((p = strrchr(fname, PATH_SEP3)) != NULL) fname = p+1;
 312 #endif
 313 #ifdef SUFFIX_SEP
 314     if ((p = strrchr(fname, SUFFIX_SEP)) != NULL) *p = '\0';
 315 #endif
 316     if (casemap('A') == 'a') strlwr(fname);
 317     return fname;
 318 }
 319
 320 /* ========================================================================
 321  * Unlink a file, working around the unlink readonly bug (if present).
 322  */
 323 int xunlink (filename)
 324      char *filename;
 325 {
 326   int r = unlink (filename);
 327
 328 #ifdef UNLINK_READONLY_BUG
 329   if (r != 0)
 330     {
 331       int e = errno;
 332       if (chmod (filename, S_IWUSR) != 0)
 333         {
 334           errno = e;
 335           return -1;
 336         }
 337
 338       r = unlink (filename);
 339     }
 340 #endif
 341
 342   return r;
 343 }
 344
 345 /* ========================================================================
 346  * Make a file name legal for file systems not allowing file names with
 347  * multiple dots or starting with a dot (such as MSDOS), by changing
 348  * all dots except the last one into underlines.  A target dependent
 349  * function can be used instead of this simple function by defining the macro
 350  * MAKE_LEGAL_NAME in tailor.h and providing the function in a target
 351  * dependent module.
 352  */
 353 void make_simple_name(name)
 354     char *name;
 355 {
 356     char *p = strrchr(name, '.');
 357     if (p == NULL) return;
 358     if (p == name) p++;
 359     do {
 360         if (*--p == '.') *p = '_';
 361     } while (p != name);
 362 }
 363
 364 /* Convert the value of the environment variable ENVVAR_NAME
 365    to a newly allocated argument vector, and set *ARGCP and *ARGVP
 366    to the number of arguments and to the vector, respectively.
 367    Make the new vector's zeroth element equal to the old **ARGVP.
 368    Return a pointer to the newly allocated string storage.
 369
 370    If the vector would be empty, do not allocate storage,
 371    do not set *ARGCP and *ARGVP, and return NULL.  */
 372
 373 #define SEPARATOR       " \t"   /* separators in env variable */
 374
 375 char *add_envopt(
 376     int *argcp,          /* pointer to argc */
 377     char ***argvp,       /* pointer to argv */
 378     char const *envvar_name) /* name of environment variable */
 379 {
 380     char *p;             /* running pointer through env variable */
 381     char **oargv;        /* runs through old argv array */
 382     char **nargv;        /* runs through new argv array */
 383     int  nargc = 0;      /* number of arguments in env variable */
 384     char *env_val;
 385
 386     env_val = getenv(envvar_name);
 387     if (env_val == NULL) return NULL;
 388
 389     env_val = xstrdup (env_val);
 390
 391     for (p = env_val; *p; nargc++ ) {        /* move through env_val */
 392         p += strspn(p, SEPARATOR);           /* skip leading separators */
 393         if (*p == '\0') break;
 394
 395         p += strcspn(p, SEPARATOR);          /* find end of word */
 396         if (*p) *p++ = '\0';                 /* mark it */
 397     }
 398     if (nargc == 0) {
 399         free(env_val);
 400         return NULL;
 401     }
 402     *argcp = nargc + 1;
 403     /* Allocate the new argv array, with an extra element just in case
 404      * the original arg list did not end with a NULL.
 405      */
 406     nargv = xcalloc (*argcp + 1, sizeof (char *));
 407     oargv  = *argvp;
 408     *argvp = nargv;
 409
 410     /* Copy the program name first */
 411     *nargv++ = *oargv;
 412
 413     /* Then copy the environment args */
 414     for (p = env_val; nargc > 0; nargc--) {
 415         p += strspn(p, SEPARATOR);           /* skip separators */
 416         *(nargv++) = p;                      /* store start */
 417         while (*p++) ;                       /* skip over word */
 418     }
 419
 420     *nargv = NULL;
 421     return env_val;
 422 }
 423
 424 /* ========================================================================
 425  * Error handlers.
 426  */
 427 void
 428 gzip_error (char const *m)
 429 {
 430     fprintf (stderr, "\n%s: %s: %s\n", program_name, ifname, m);
 431     abort_gzip();
 432 }
 433
 434 void
 435 xalloc_die ()
 436 {
 437   fprintf (stderr, "\n%s: memory_exhausted\n", program_name);
 438   abort_gzip ();
 439 }
 440
 441 void warning (char const *m)
 442 {
 443     WARN ((stderr, "%s: %s: warning: %s\n", program_name, ifname, m));
 444 }
 445
 446 void read_error()
 447 {
 448     int e = errno;
 449     fprintf (stderr, "\n%s: ", program_name);
 450     if (e != 0) {
 451         errno = e;
 452         perror(ifname);
 453     } else {
 454         fprintf(stderr, "%s: unexpected end of file\n", ifname);
 455     }
 456     abort_gzip();
 457 }
 458
 459 void write_error()
 460 {
 461     int e = errno;
 462     fprintf (stderr, "\n%s: ", program_name);
 463     errno = e;
 464     perror(ofname);
 465     abort_gzip();
 466 }
 467
 468 /* ========================================================================
 469  * Display compression ratio on the given stream on 6 characters.
 470  */
 471 void display_ratio(num, den, file)
 472     off_t num;
 473     off_t den;
 474     FILE *file;
 475 {
 476     fprintf(file, "%5.1f%%", den == 0 ? 0 : 100.0 * num / den);
 477 }
 478
 479 /* ========================================================================
 480  * Print an off_t.  There's no completely portable way to use printf,
 481  * so we do it ourselves.
 482  */
 483 void fprint_off(file, offset, width)
 484     FILE *file;
 485     off_t offset;
 486     int width;
 487 {
 488     char buf[CHAR_BIT * sizeof (off_t)];
 489     char *p = buf + sizeof buf;
 490
 491     /* Don't negate offset here; it might overflow.  */
 492     if (offset < 0) {
 493         do
 494           *--p = '0' - offset % 10;
 495         while ((offset /= 10) != 0);
 496
 497         *--p = '-';
 498     } else {
 499         do
 500           *--p = '0' + offset % 10;
 501         while ((offset /= 10) != 0);
 502     }
 503
 504     width -= buf + sizeof buf - p;
 505     while (0 < width--) {
 506         putc (' ', file);
 507     }
 508     for (;  p < buf + sizeof buf;  p++)
 509         putc (*p, file);
 510 }