Import file-5.10.
[dragonfly.git] / contrib / file / src / compress.c
CommitLineData
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1/*
2 * Copyright (c) Ian F. Darwin 1986-1995.
3 * Software written by Ian F. Darwin and others;
4 * maintained 1995-present by Christos Zoulas and others.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice immediately at the beginning of the file, without modification,
11 * this list of conditions, and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28/*
29 * compress routines:
30 * zmagic() - returns 0 if not recognized, uncompresses and prints
31 * information if recognized
32 * uncompress(method, old, n, newch) - uncompress old into new,
33 * using method, return sizeof new
34 */
35#include "file.h"
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36
37#ifndef lint
9f86ab30 38FILE_RCSID("@(#)$File: compress.c,v 1.68 2011/12/08 12:38:24 rrt Exp $")
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39#endif
40
ab0b56cc 41#include "magic.h"
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42#include <stdlib.h>
43#ifdef HAVE_UNISTD_H
44#include <unistd.h>
45#endif
46#include <string.h>
47#include <errno.h>
e4d4ce0c 48#ifndef __MINGW32__
9b22a626 49#include <sys/ioctl.h>
e4d4ce0c 50#endif
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51#ifdef HAVE_SYS_WAIT_H
52#include <sys/wait.h>
53#endif
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54#if defined(HAVE_SYS_TIME_H)
55#include <sys/time.h>
56#endif
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57#if defined(HAVE_ZLIB_H) && defined(HAVE_LIBZ)
58#define BUILTIN_DECOMPRESS
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59#include <zlib.h>
60#endif
61
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62private const struct {
63 const char magic[8];
ab0b56cc 64 size_t maglen;
79343712 65 const char *argv[3];
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66 int silent;
67} compr[] = {
68 { "\037\235", 2, { "gzip", "-cdq", NULL }, 1 }, /* compressed */
69 /* Uncompress can get stuck; so use gzip first if we have it
70 * Idea from Damien Clark, thanks! */
71 { "\037\235", 2, { "uncompress", "-c", NULL }, 1 }, /* compressed */
72 { "\037\213", 2, { "gzip", "-cdq", NULL }, 1 }, /* gzipped */
73 { "\037\236", 2, { "gzip", "-cdq", NULL }, 1 }, /* frozen */
74 { "\037\240", 2, { "gzip", "-cdq", NULL }, 1 }, /* SCO LZH */
75 /* the standard pack utilities do not accept standard input */
76 { "\037\036", 2, { "gzip", "-cdq", NULL }, 0 }, /* packed */
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77 { "PK\3\4", 4, { "gzip", "-cdq", NULL }, 1 }, /* pkzipped, */
78 /* ...only first file examined */
ab0b56cc 79 { "BZh", 3, { "bzip2", "-cd", NULL }, 1 }, /* bzip2-ed */
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80 { "LZIP", 4, { "lzip", "-cdq", NULL }, 1 },
81 { "\3757zXZ\0",6,{ "xz", "-cd", NULL }, 1 }, /* XZ Utils */
ff91a668 82 { "LRZI", 4, { "lrzip", "-dqo-", NULL }, 1 }, /* LRZIP */
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83};
84
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85#define NODATA ((size_t)~0)
86
ab0b56cc 87private ssize_t swrite(int, const void *, size_t);
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88#if HAVE_FORK
89private size_t ncompr = sizeof(compr) / sizeof(compr[0]);
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90private size_t uncompressbuf(struct magic_set *, int, size_t,
91 const unsigned char *, unsigned char **, size_t);
05a9c884 92#ifdef BUILTIN_DECOMPRESS
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93private size_t uncompressgzipped(struct magic_set *, const unsigned char *,
94 unsigned char **, size_t);
95#endif
96
97protected int
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98file_zmagic(struct magic_set *ms, int fd, const char *name,
99 const unsigned char *buf, size_t nbytes)
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100{
101 unsigned char *newbuf = NULL;
102 size_t i, nsz;
103 int rv = 0;
05a9c884 104 int mime = ms->flags & MAGIC_MIME;
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105
106 if ((ms->flags & MAGIC_COMPRESS) == 0)
107 return 0;
108
109 for (i = 0; i < ncompr; i++) {
110 if (nbytes < compr[i].maglen)
111 continue;
112 if (memcmp(buf, compr[i].magic, compr[i].maglen) == 0 &&
113 (nsz = uncompressbuf(ms, fd, i, buf, &newbuf,
9b22a626 114 nbytes)) != NODATA) {
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115 ms->flags &= ~MAGIC_COMPRESS;
116 rv = -1;
393abec0 117 if (file_buffer(ms, -1, name, newbuf, nsz) == -1)
ab0b56cc 118 goto error;
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119
120 if (mime == MAGIC_MIME || mime == 0) {
121 if (file_printf(ms, mime ?
122 " compressed-encoding=" : " (") == -1)
123 goto error;
124 }
125
126 if ((mime == 0 || mime & MAGIC_MIME_ENCODING) &&
127 file_buffer(ms, -1, NULL, buf, nbytes) == -1)
ab0b56cc 128 goto error;
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129
130 if (!mime && file_printf(ms, ")") == -1)
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131 goto error;
132 rv = 1;
133 break;
134 }
135 }
136error:
9f86ab30 137 free(newbuf);
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138 ms->flags |= MAGIC_COMPRESS;
139 return rv;
140}
e4d4ce0c 141#endif
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142/*
143 * `safe' write for sockets and pipes.
144 */
145private ssize_t
146swrite(int fd, const void *buf, size_t n)
147{
f72f8299 148 ssize_t rv;
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149 size_t rn = n;
150
151 do
152 switch (rv = write(fd, buf, n)) {
153 case -1:
154 if (errno == EINTR)
155 continue;
156 return -1;
157 default:
158 n -= rv;
f72f8299 159 buf = CAST(const char *, buf) + rv;
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160 break;
161 }
162 while (n > 0);
163 return rn;
164}
165
166
167/*
168 * `safe' read for sockets and pipes.
169 */
9b22a626 170protected ssize_t
e4d4ce0c 171sread(int fd, void *buf, size_t n, int canbepipe __attribute__ ((unused)))
ab0b56cc 172{
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173 ssize_t rv;
174#ifdef FD_ZERO
175 ssize_t cnt;
176#endif
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177#ifdef FIONREAD
178 int t = 0;
179#endif
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180 size_t rn = n;
181
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182 if (fd == STDIN_FILENO)
183 goto nocheck;
184
185#ifdef FIONREAD
09b9c1a5 186 if ((canbepipe && (ioctl(fd, FIONREAD, &t) == -1)) || (t == 0)) {
9b22a626 187#ifdef FD_ZERO
393abec0 188 for (cnt = 0;; cnt++) {
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189 fd_set check;
190 struct timeval tout = {0, 100 * 1000};
09b9c1a5 191 int selrv;
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192
193 FD_ZERO(&check);
194 FD_SET(fd, &check);
195
196 /*
197 * Avoid soft deadlock: do not read if there
198 * is nothing to read from sockets and pipes.
199 */
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200 selrv = select(fd + 1, &check, NULL, NULL, &tout);
201 if (selrv == -1) {
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202 if (errno == EINTR || errno == EAGAIN)
203 continue;
09b9c1a5 204 } else if (selrv == 0 && cnt >= 5) {
9b22a626 205 return 0;
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206 } else
207 break;
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208 }
209#endif
210 (void)ioctl(fd, FIONREAD, &t);
211 }
212
213 if (t > 0 && (size_t)t < n) {
214 n = t;
215 rn = n;
216 }
217#endif
218
219nocheck:
ab0b56cc 220 do
9b22a626 221 switch ((rv = read(fd, buf, n))) {
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222 case -1:
223 if (errno == EINTR)
224 continue;
225 return -1;
226 case 0:
227 return rn - n;
228 default:
229 n -= rv;
230 buf = ((char *)buf) + rv;
231 break;
232 }
233 while (n > 0);
234 return rn;
235}
236
237protected int
238file_pipe2file(struct magic_set *ms, int fd, const void *startbuf,
239 size_t nbytes)
240{
241 char buf[4096];
f72f8299 242 ssize_t r;
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243 int tfd;
244#ifdef HAVE_MKSTEMP
245 int te;
246#endif
ab0b56cc 247
79343712 248 (void)strlcpy(buf, "/tmp/file.XXXXXX", sizeof buf);
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249#ifndef HAVE_MKSTEMP
250 {
251 char *ptr = mktemp(buf);
252 tfd = open(ptr, O_RDWR|O_TRUNC|O_EXCL|O_CREAT, 0600);
253 r = errno;
254 (void)unlink(ptr);
255 errno = r;
256 }
257#else
258 tfd = mkstemp(buf);
f72f8299 259 te = errno;
ab0b56cc 260 (void)unlink(buf);
f72f8299 261 errno = te;
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262#endif
263 if (tfd == -1) {
264 file_error(ms, errno,
265 "cannot create temporary file for pipe copy");
266 return -1;
267 }
268
269 if (swrite(tfd, startbuf, nbytes) != (ssize_t)nbytes)
270 r = 1;
271 else {
393abec0 272 while ((r = sread(fd, buf, sizeof(buf), 1)) > 0)
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273 if (swrite(tfd, buf, (size_t)r) != r)
274 break;
275 }
276
277 switch (r) {
278 case -1:
279 file_error(ms, errno, "error copying from pipe to temp file");
280 return -1;
281 case 0:
282 break;
283 default:
284 file_error(ms, errno, "error while writing to temp file");
285 return -1;
286 }
287
288 /*
289 * We duplicate the file descriptor, because fclose on a
290 * tmpfile will delete the file, but any open descriptors
291 * can still access the phantom inode.
292 */
293 if ((fd = dup2(tfd, fd)) == -1) {
294 file_error(ms, errno, "could not dup descriptor for temp file");
295 return -1;
296 }
297 (void)close(tfd);
298 if (lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) {
299 file_badseek(ms);
300 return -1;
301 }
302 return fd;
303}
e4d4ce0c 304#if HAVE_FORK
05a9c884 305#ifdef BUILTIN_DECOMPRESS
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306
307#define FHCRC (1 << 1)
308#define FEXTRA (1 << 2)
309#define FNAME (1 << 3)
310#define FCOMMENT (1 << 4)
311
312private size_t
313uncompressgzipped(struct magic_set *ms, const unsigned char *old,
314 unsigned char **newch, size_t n)
315{
316 unsigned char flg = old[3];
317 size_t data_start = 10;
318 z_stream z;
319 int rc;
320
321 if (flg & FEXTRA) {
322 if (data_start+1 >= n)
323 return 0;
324 data_start += 2 + old[data_start] + old[data_start + 1] * 256;
325 }
326 if (flg & FNAME) {
327 while(data_start < n && old[data_start])
328 data_start++;
329 data_start++;
330 }
331 if(flg & FCOMMENT) {
332 while(data_start < n && old[data_start])
333 data_start++;
334 data_start++;
335 }
336 if(flg & FHCRC)
337 data_start += 2;
338
339 if (data_start >= n)
340 return 0;
79343712 341 if ((*newch = CAST(unsigned char *, malloc(HOWMANY + 1))) == NULL) {
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342 return 0;
343 }
344
345 /* XXX: const castaway, via strchr */
346 z.next_in = (Bytef *)strchr((const char *)old + data_start,
347 old[data_start]);
f72f8299 348 z.avail_in = CAST(uint32_t, (n - data_start));
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349 z.next_out = *newch;
350 z.avail_out = HOWMANY;
351 z.zalloc = Z_NULL;
352 z.zfree = Z_NULL;
353 z.opaque = Z_NULL;
354
f72f8299 355 /* LINTED bug in header macro */
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356 rc = inflateInit2(&z, -15);
357 if (rc != Z_OK) {
358 file_error(ms, 0, "zlib: %s", z.msg);
359 return 0;
360 }
361
362 rc = inflate(&z, Z_SYNC_FLUSH);
363 if (rc != Z_OK && rc != Z_STREAM_END) {
364 file_error(ms, 0, "zlib: %s", z.msg);
365 return 0;
366 }
367
368 n = (size_t)z.total_out;
393abec0 369 (void)inflateEnd(&z);
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370
371 /* let's keep the nul-terminate tradition */
9b22a626 372 (*newch)[n] = '\0';
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373
374 return n;
375}
376#endif
377
378private size_t
379uncompressbuf(struct magic_set *ms, int fd, size_t method,
380 const unsigned char *old, unsigned char **newch, size_t n)
381{
382 int fdin[2], fdout[2];
f72f8299 383 ssize_t r;
a96e001b 384 pid_t pid;
ab0b56cc 385
05a9c884 386#ifdef BUILTIN_DECOMPRESS
79343712 387 /* FIXME: This doesn't cope with bzip2 */
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388 if (method == 2)
389 return uncompressgzipped(ms, old, newch, n);
390#endif
391 (void)fflush(stdout);
392 (void)fflush(stderr);
393
394 if ((fd != -1 && pipe(fdin) == -1) || pipe(fdout) == -1) {
395 file_error(ms, errno, "cannot create pipe");
9b22a626 396 return NODATA;
ab0b56cc 397 }
a96e001b 398 switch (pid = fork()) {
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399 case 0: /* child */
400 (void) close(0);
401 if (fd != -1) {
402 (void) dup(fd);
403 (void) lseek(0, (off_t)0, SEEK_SET);
404 } else {
405 (void) dup(fdin[0]);
406 (void) close(fdin[0]);
407 (void) close(fdin[1]);
408 }
409
410 (void) close(1);
411 (void) dup(fdout[1]);
412 (void) close(fdout[0]);
413 (void) close(fdout[1]);
414#ifndef DEBUG
415 if (compr[method].silent)
416 (void)close(2);
417#endif
418
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419 (void)execvp(compr[method].argv[0],
420 (char *const *)(intptr_t)compr[method].argv);
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421#ifdef DEBUG
422 (void)fprintf(stderr, "exec `%s' failed (%s)\n",
423 compr[method].argv[0], strerror(errno));
424#endif
425 exit(1);
426 /*NOTREACHED*/
427 case -1:
428 file_error(ms, errno, "could not fork");
9b22a626 429 return NODATA;
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430
431 default: /* parent */
432 (void) close(fdout[1]);
433 if (fd == -1) {
434 (void) close(fdin[0]);
435 /*
436 * fork again, to avoid blocking because both
437 * pipes filled
438 */
439 switch (fork()) {
440 case 0: /* child */
441 (void)close(fdout[0]);
393abec0 442 if (swrite(fdin[1], old, n) != (ssize_t)n) {
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443#ifdef DEBUG
444 (void)fprintf(stderr,
445 "Write failed (%s)\n",
446 strerror(errno));
447#endif
448 exit(1);
449 }
450 exit(0);
451 /*NOTREACHED*/
452
453 case -1:
454#ifdef DEBUG
455 (void)fprintf(stderr, "Fork failed (%s)\n",
456 strerror(errno));
457#endif
458 exit(1);
459 /*NOTREACHED*/
460
461 default: /* parent */
462 break;
463 }
464 (void) close(fdin[1]);
465 fdin[1] = -1;
466 }
467
468 if ((*newch = (unsigned char *) malloc(HOWMANY + 1)) == NULL) {
469#ifdef DEBUG
470 (void)fprintf(stderr, "Malloc failed (%s)\n",
471 strerror(errno));
472#endif
473 n = 0;
474 goto err;
475 }
393abec0 476 if ((r = sread(fdout[0], *newch, HOWMANY, 0)) <= 0) {
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477#ifdef DEBUG
478 (void)fprintf(stderr, "Read failed (%s)\n",
479 strerror(errno));
480#endif
481 free(*newch);
482 n = 0;
483 newch[0] = '\0';
484 goto err;
485 } else {
486 n = r;
487 }
488 /* NUL terminate, as every buffer is handled here. */
9b22a626 489 (*newch)[n] = '\0';
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490err:
491 if (fdin[1] != -1)
492 (void) close(fdin[1]);
493 (void) close(fdout[0]);
494#ifdef WNOHANG
a96e001b 495 while (waitpid(pid, NULL, WNOHANG) != -1)
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496 continue;
497#else
498 (void)wait(NULL);
499#endif
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500 (void) close(fdin[0]);
501
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502 return n;
503 }
504}
e4d4ce0c 505#endif