1 /* util.c -- utility functions for gzip support
2
3 Copyright (C) 1997-1999, 2001-2002, 2006, 2009-2023 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 #include <limits.h>
25 #include <unistd.h>
26 #include <fcntl.h>
27 #include <stdlib.h>
28 #include <errno.h>
29
30 #include "tailor.h"
31 #include "gzip.h"
32 #include <dirname.h>
33 #include <xalloc.h>
34
35 #ifndef CHAR_BIT
36 # define CHAR_BIT 8
37 #endif
38
39 #ifndef EPIPE
40 # define EPIPE 0
41 #endif
42
43 static int write_buffer (int, voidp, unsigned int);
44
45 /* ========================================================================
46 * Table of CRC-32's of all single-byte values (made by makecrc.c)
47 */
48 static const ulg crc_32_tab[] = {
49 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
50 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
51 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
52 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
53 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
54 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
55 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
56 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
57 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
58 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
59 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
60 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
61 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
62 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
63 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
64 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
65 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
66 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
67 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
68 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
69 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
70 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
71 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
72 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
73 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
74 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
75 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
76 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
77 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
78 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
79 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
80 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
81 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
82 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
83 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
84 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
85 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
86 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
87 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
88 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
89 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
90 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
91 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
92 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
93 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
94 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
95 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
96 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
97 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
98 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
99 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
100 0x2d02ef8dL
101 };
102
103 /* Shift register contents. */
104 static ulg crc = 0xffffffffL;
105
106 /* ===========================================================================
107 * Copy input to output unchanged: zcat == cat with --force.
108 * IN assertion: insize bytes have already been read in inbuf and inptr bytes
109 * already processed or copied.
110 * 'in' and 'out' are the input and output file descriptors.
111 */
112 int
113 copy (int in, int out)
114 {
115 int got;
116
117 errno = 0;
118 while (insize > inptr) {
119 write_buf(out, (char*)inbuf + inptr, insize - inptr);
120 got = read_buffer (in, (char *) inbuf, INBUFSIZ);
121 if (got == -1)
122 read_error();
123 bytes_in += got;
124 insize = (unsigned)got;
125 inptr = 0;
126 }
127 return OK;
128 }
129
130 /* ===========================================================================
131 * Run a set of bytes through the crc shift register. If s is a NULL
132 * pointer, then initialize the crc shift register contents instead.
133 * Return the current crc in either case.
134 * S points to N bytes to pump through.
135 */
136 ulg
137 updcrc (uch const *s, unsigned n)
138 {
139 register ulg c; /* temporary variable */
140
141 if (s == NULL) {
142 c = 0xffffffffL;
143 } else {
144 c = crc;
145 if (n) do {
146 c = crc_32_tab[((int)c ^ (*s++)) & 0xff] ^ (c >> 8);
147 } while (--n);
148 }
149 crc = c;
150 return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */
151 }
152
153 /* Return a current CRC value. */
154 ulg
155 getcrc ()
156 {
157 return crc ^ 0xffffffffL;
158 }
159
160 #ifdef IBM_Z_DFLTCC
161 /* Set a new CRC value. */
162 void
163 setcrc (ulg c)
164 {
165 crc = c ^ 0xffffffffL;
166 }
167 #endif
168
169 /* ===========================================================================
170 * Clear input and output buffers
171 */
172 void clear_bufs()
173 {
174 outcnt = 0;
175 insize = inptr = 0;
176 bytes_in = bytes_out = 0L;
177 }
178
179 /* ===========================================================================
180 * Fill the input buffer. This is called only when the buffer is empty.
181 * EOF_OK is set if EOF acceptable as a result.
182 */
183 int
184 fill_inbuf (int eof_ok)
185 {
186 int len;
187
188 /* Read as much as possible */
189 insize = 0;
190 do {
191 len = read_buffer (ifd, (char *) inbuf + insize, INBUFSIZ - insize);
192 if (len == 0) break;
193 if (len == -1) {
194 read_error();
195 break;
196 }
197 insize += len;
198 } while (insize < INBUFSIZ);
199
200 if (insize == 0) {
201 if (eof_ok) return EOF;
202 flush_window();
203 errno = 0;
204 read_error();
205 }
206 bytes_in += (off_t)insize;
207 inptr = 1;
208 return inbuf[0];
209 }
210
211 /* Like the standard read function, except do not attempt to read more
212 than INT_MAX bytes at a time. */
213 int
214 read_buffer (int fd, voidp buf, unsigned int cnt)
215 {
216 int len;
217 if (INT_MAX < cnt)
218 cnt = INT_MAX;
219 len = read (fd, buf, cnt);
220
221 #if defined F_SETFL && O_NONBLOCK && defined EAGAIN
222 /* Input files are opened O_NONBLOCK for security reasons. On some
223 file systems this can cause read to fail with errno == EAGAIN. */
224 if (len < 0 && errno == EAGAIN)
225 {
226 int flags = fcntl (fd, F_GETFL);
227 if (0 <= flags)
228 {
229 if (! (flags & O_NONBLOCK))
230 errno = EAGAIN;
231 else if (fcntl (fd, F_SETFL, flags & ~O_NONBLOCK) != -1)
232 len = read (fd, buf, cnt);
233 }
234 }
235 #endif
236
237 return len;
238 }
239
240 /* Likewise for 'write'. */
241 static int
242 write_buffer (int fd, voidp buf, unsigned int cnt)
243 {
244 if (INT_MAX < cnt)
245 cnt = INT_MAX;
246 return write (fd, buf, cnt);
247 }
248
249 /* ===========================================================================
250 * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
251 * (used for the compressed data only)
252 */
253 void flush_outbuf()
254 {
255 if (outcnt == 0) return;
256
257 write_buf (ofd, outbuf, outcnt);
258 outcnt = 0;
259 }
260
261 /* ===========================================================================
262 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
263 * (Used for the decompressed data only.)
264 */
265 void flush_window()
266 {
267 if (outcnt == 0) return;
268 updcrc(window, outcnt);
269
270 write_buf (ofd, window, outcnt);
271 outcnt = 0;
272 }
273
274 /* ===========================================================================
275 * Update the count of output bytes. If testing, do not do any
276 * output. Otherwise, write the buffer, checking for errors.
277 */
278 void
279 write_buf (int fd, voidp buf, unsigned cnt)
280 {
281 unsigned n;
282
283 bytes_out += cnt;
284 if (test)
285 return;
286
287 while ((n = write_buffer (fd, buf, cnt)) != cnt) {
288 if (n == (unsigned)(-1)) {
289 write_error();
290 }
291 cnt -= n;
292 buf = (voidp)((char*)buf+n);
293 }
294 }
295
296 /* ========================================================================
297 * Put string s in lower case, return s.
298 */
299 char *
300 strlwr (char *s)
301 {
302 char *t;
303 for (t = s; *t; t++)
304 *t = tolow ((unsigned char) *t);
305 return s;
306 }
307
308 /* ========================================================================
309 * Return the base name of a file (remove any directory prefix and
310 * any version suffix). For systems with file names that are not
311 * case sensitive, force the base name to lower case.
312 */
313 char *
314 gzip_base_name (char *fname)
315 {
316 fname = last_component (fname);
317 if (casemap('A') == 'a') strlwr(fname);
318 return fname;
319 }
320
321 /* ========================================================================
322 * Unlink a file, working around the unlink readonly bug (if present).
323 */
324 int
325 xunlink (char *filename)
326 {
327 int r = unlink (filename);
328
329 #ifdef UNLINK_READONLY_BUG
330 if (r != 0)
331 {
332 int e = errno;
333 if (chmod (filename, S_IWUSR) != 0)
334 {
335 errno = e;
336 return -1;
337 }
338
339 r = unlink (filename);
340 }
341 #endif
342
343 return r;
344 }
345
346 #ifdef NO_MULTIPLE_DOTS
347 /* ========================================================================
348 * Make a file name legal for file systems not allowing file names with
349 * multiple dots or starting with a dot (such as MSDOS), by changing
350 * all dots except the last one into underlines. A target dependent
351 * function can be used instead of this simple function by defining the macro
352 * MAKE_LEGAL_NAME in tailor.h and providing the function in a target
353 * dependent module.
354 */
355 void
356 make_simple_name (char *name)
357 {
358 char *p = strrchr(name, '.');
359 if (p == NULL) return;
360 if (p == name) p++;
361 do {
362 if (*--p == '.') *p = '_';
363 } while (p != name);
364 }
365 #endif
366
367 /* Convert the value of the environment variable ENVVAR_NAME
368 to a newly allocated argument vector, and set *ARGCP and *ARGVP
369 to the number of arguments and to the vector, respectively.
370 Make the new vector's zeroth element equal to the old **ARGVP.
371 Return a pointer to the newly allocated string storage.
372
373 If the vector would be empty, do not allocate storage,
374 do not set *ARGCP and *ARGVP, and return NULL. */
375
376 #define SEPARATOR " \t" /* separators in env variable */
377
378 char *add_envopt(
379 int *argcp, /* pointer to argc */
380 char ***argvp, /* pointer to argv */
381 char const *envvar_name) /* name of environment variable */
382 {
383 char *p; /* running pointer through env variable */
384 char **oargv; /* runs through old argv array */
385 char **nargv; /* runs through new argv array */
386 int nargc = 0; /* number of arguments in env variable */
387 char *env_val;
388
389 env_val = getenv(envvar_name);
390 if (env_val == NULL) return NULL;
391
392 env_val = xstrdup (env_val);
393
394 for (p = env_val; *p; nargc++ ) { /* move through env_val */
395 p += strspn(p, SEPARATOR); /* skip leading separators */
396 if (*p == '\0') break;
397
398 p += strcspn(p, SEPARATOR); /* find end of word */
399 if (*p) *p++ = '\0'; /* mark it */
400 }
401 if (nargc == 0) {
402 free(env_val);
403 return NULL;
404 }
405 *argcp = nargc + 1;
406 /* Allocate the new argv array, with an extra element just in case
407 * the original arg list did not end with a NULL.
408 */
409 nargv = xcalloc (*argcp + 1, sizeof (char *));
410 oargv = *argvp;
411 *argvp = nargv;
412
413 /* Copy the program name first */
414 *nargv++ = *oargv;
415
416 /* Then copy the environment args */
417 for (p = env_val; nargc > 0; nargc--) {
418 p += strspn(p, SEPARATOR); /* skip separators */
419 *(nargv++) = p; /* store start */
420 while (*p++) ; /* skip over word */
421 }
422
423 *nargv = NULL;
424 return env_val;
425 }
426
427 /* ========================================================================
428 * Error handlers.
429 */
430 void
431 gzip_error (char const *m)
432 {
433 fprintf (stderr, "\n%s: %s: %s\n", program_name, ifname, m);
434 abort_gzip();
435 }
436
437 void
438 xalloc_die ()
439 {
440 fprintf (stderr, "\n%s: memory_exhausted\n", program_name);
441 abort_gzip ();
442 }
443
444 void warning (char const *m)
445 {
446 WARN ((stderr, "%s: %s: warning: %s\n", program_name, ifname, m));
447 }
448
449 void read_error()
450 {
451 fprintf (stderr, "\n%s: %s: %s\n",
452 program_name, ifname,
453 errno ? strerror (errno) : "unexpected end of file");
454 abort_gzip();
455 }
456
457 void write_error()
458 {
459 int exitcode = errno == EPIPE ? WARNING : ERROR;
460 if (! (exitcode == WARNING && quiet))
461 fprintf (stderr, "\n%s: %s: %s\n", program_name, ofname, strerror (errno));
462 finish_up_gzip (exitcode);
463 }
464
465 /* ========================================================================
466 * Display compression ratio on the given stream on 6 characters.
467 */
468 void
469 display_ratio (off_t num, off_t den, FILE *file)
470 {
471 fprintf(file, "%5.1f%%", den == 0 ? 0 : 100.0 * num / den);
472 }
473
474 /* ========================================================================
475 * Print an off_t. There's no completely portable way to use printf,
476 * so we do it ourselves.
477 */
478 void
479 fprint_off (FILE *file, off_t offset, int width)
480 {
481 char buf[CHAR_BIT * sizeof (off_t)];
482 char *p = buf + sizeof buf;
483
484 /* Don't negate offset here; it might overflow. */
485 if (offset < 0) {
486 do
487 *--p = '0' - offset % 10;
488 while ((offset /= 10) != 0);
489
490 *--p = '-';
491 } else {
492 do
493 *--p = '0' + offset % 10;
494 while ((offset /= 10) != 0);
495 }
496
497 width -= buf + sizeof buf - p;
498 while (0 < width--) {
499 putc (' ', file);
500 }
501 for (; p < buf + sizeof buf; p++)
502 putc (*p, file);
503 }