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.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
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
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
38 FILE_RCSID("@(#)$File: compress.c,v 1.80 2015/06/03 18:21:24 christos Exp $")
51 typedef void (*sig_t)(int);
52 # endif /* HAVE_SIG_T */
54 #if !defined(__MINGW32__) && !defined(WIN32)
55 #include <sys/ioctl.h>
57 #ifdef HAVE_SYS_WAIT_H
60 #if defined(HAVE_SYS_TIME_H)
63 #if defined(HAVE_ZLIB_H) && defined(HAVE_LIBZ)
64 #define BUILTIN_DECOMPRESS
68 private const struct {
74 { "\037\235", 2, { "gzip", "-cdq", NULL }, 1 }, /* compressed */
75 /* Uncompress can get stuck; so use gzip first if we have it
76 * Idea from Damien Clark, thanks! */
77 { "\037\235", 2, { "uncompress", "-c", NULL }, 1 }, /* compressed */
78 { "\037\213", 2, { "gzip", "-cdq", NULL }, 1 }, /* gzipped */
79 { "\037\236", 2, { "gzip", "-cdq", NULL }, 1 }, /* frozen */
80 { "\037\240", 2, { "gzip", "-cdq", NULL }, 1 }, /* SCO LZH */
81 /* the standard pack utilities do not accept standard input */
82 { "\037\036", 2, { "gzip", "-cdq", NULL }, 0 }, /* packed */
83 { "PK\3\4", 4, { "gzip", "-cdq", NULL }, 1 }, /* pkzipped, */
84 /* ...only first file examined */
85 { "BZh", 3, { "bzip2", "-cd", NULL }, 1 }, /* bzip2-ed */
86 { "LZIP", 4, { "lzip", "-cdq", NULL }, 1 },
87 { "\3757zXZ\0",6,{ "xz", "-cd", NULL }, 1 }, /* XZ Utils */
88 { "LRZI", 4, { "lrzip", "-dqo-", NULL }, 1 }, /* LRZIP */
89 { "\004\"M\030", 4, { "lz4", "-cd", NULL }, 1 }, /* LZ4 */
92 #define NODATA ((size_t)~0)
94 private ssize_t swrite(int, const void *, size_t);
96 private size_t ncompr = sizeof(compr) / sizeof(compr[0]);
97 private size_t uncompressbuf(struct magic_set *, int, size_t,
98 const unsigned char *, unsigned char **, size_t);
99 #ifdef BUILTIN_DECOMPRESS
100 private size_t uncompressgzipped(struct magic_set *, const unsigned char *,
101 unsigned char **, size_t);
105 file_zmagic(struct magic_set *ms, int fd, const char *name,
106 const unsigned char *buf, size_t nbytes)
108 unsigned char *newbuf = NULL;
111 int mime = ms->flags & MAGIC_MIME;
116 if ((ms->flags & MAGIC_COMPRESS) == 0)
120 osigpipe = signal(SIGPIPE, SIG_IGN);
122 for (i = 0; i < ncompr; i++) {
123 if (nbytes < compr[i].maglen)
125 if (memcmp(buf, compr[i].magic, compr[i].maglen) == 0 &&
126 (nsz = uncompressbuf(ms, fd, i, buf, &newbuf,
127 nbytes)) != NODATA) {
128 ms->flags &= ~MAGIC_COMPRESS;
130 if (file_buffer(ms, -1, name, newbuf, nsz) == -1)
133 if ((ms->flags & MAGIC_COMPRESS_TRANSP) == 0 &&
134 (mime == MAGIC_MIME || mime == 0)) {
135 if (file_printf(ms, mime ?
136 " compressed-encoding=" : " (") == -1)
138 if (file_buffer(ms, -1, NULL, buf, nbytes) == -1)
140 if (!mime && file_printf(ms, ")") == -1)
150 (void)signal(SIGPIPE, osigpipe);
153 ms->flags |= MAGIC_COMPRESS;
158 * `safe' write for sockets and pipes.
161 swrite(int fd, const void *buf, size_t n)
167 switch (rv = write(fd, buf, n)) {
174 buf = CAST(const char *, buf) + rv;
183 * `safe' read for sockets and pipes.
186 sread(int fd, void *buf, size_t n, int canbepipe __attribute__((__unused__)))
194 if (fd == STDIN_FILENO)
198 if (canbepipe && (ioctl(fd, FIONREAD, &t) == -1 || t == 0)) {
201 for (cnt = 0;; cnt++) {
203 struct timeval tout = {0, 100 * 1000};
210 * Avoid soft deadlock: do not read if there
211 * is nothing to read from sockets and pipes.
213 selrv = select(fd + 1, &check, NULL, NULL, &tout);
215 if (errno == EINTR || errno == EAGAIN)
217 } else if (selrv == 0 && cnt >= 5) {
223 (void)ioctl(fd, FIONREAD, &t);
226 if (t > 0 && (size_t)t < n) {
234 switch ((rv = read(fd, buf, n))) {
243 buf = ((char *)buf) + rv;
251 file_pipe2file(struct magic_set *ms, int fd, const void *startbuf,
258 (void)strlcpy(buf, "/tmp/file.XXXXXX", sizeof buf);
261 char *ptr = mktemp(buf);
262 tfd = open(ptr, O_RDWR|O_TRUNC|O_EXCL|O_CREAT, 0600);
277 file_error(ms, errno,
278 "cannot create temporary file for pipe copy");
282 if (swrite(tfd, startbuf, nbytes) != (ssize_t)nbytes)
285 while ((r = sread(fd, buf, sizeof(buf), 1)) > 0)
286 if (swrite(tfd, buf, (size_t)r) != r)
292 file_error(ms, errno, "error copying from pipe to temp file");
297 file_error(ms, errno, "error while writing to temp file");
302 * We duplicate the file descriptor, because fclose on a
303 * tmpfile will delete the file, but any open descriptors
304 * can still access the phantom inode.
306 if ((fd = dup2(tfd, fd)) == -1) {
307 file_error(ms, errno, "could not dup descriptor for temp file");
311 if (lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) {
318 #ifdef BUILTIN_DECOMPRESS
320 #define FHCRC (1 << 1)
321 #define FEXTRA (1 << 2)
322 #define FNAME (1 << 3)
323 #define FCOMMENT (1 << 4)
326 uncompressgzipped(struct magic_set *ms, const unsigned char *old,
327 unsigned char **newch, size_t n)
329 unsigned char flg = old[3];
330 size_t data_start = 10;
335 if (data_start+1 >= n)
337 data_start += 2 + old[data_start] + old[data_start + 1] * 256;
340 while(data_start < n && old[data_start])
345 while(data_start < n && old[data_start])
354 if ((*newch = CAST(unsigned char *, malloc(HOWMANY + 1))) == NULL) {
358 /* XXX: const castaway, via strchr */
359 z.next_in = (Bytef *)strchr((const char *)old + data_start,
361 z.avail_in = CAST(uint32_t, (n - data_start));
363 z.avail_out = HOWMANY;
368 /* LINTED bug in header macro */
369 rc = inflateInit2(&z, -15);
371 file_error(ms, 0, "zlib: %s", z.msg);
375 rc = inflate(&z, Z_SYNC_FLUSH);
376 if (rc != Z_OK && rc != Z_STREAM_END) {
377 file_error(ms, 0, "zlib: %s", z.msg);
381 n = (size_t)z.total_out;
382 (void)inflateEnd(&z);
384 /* let's keep the nul-terminate tradition */
392 uncompressbuf(struct magic_set *ms, int fd, size_t method,
393 const unsigned char *old, unsigned char **newch, size_t n)
395 int fdin[2], fdout[2];
399 #ifdef BUILTIN_DECOMPRESS
400 /* FIXME: This doesn't cope with bzip2 */
402 return uncompressgzipped(ms, old, newch, n);
404 (void)fflush(stdout);
405 (void)fflush(stderr);
407 if ((fd != -1 && pipe(fdin) == -1) || pipe(fdout) == -1) {
408 file_error(ms, errno, "cannot create pipe");
417 (void) lseek(0, (off_t)0, SEEK_SET);
419 if (dup(fdin[0]) == -1)
421 (void) close(fdin[0]);
422 (void) close(fdin[1]);
426 if (dup(fdout[1]) == -1)
428 (void) close(fdout[0]);
429 (void) close(fdout[1]);
431 if (compr[method].silent)
435 (void)execvp(compr[method].argv[0],
436 (char *const *)(intptr_t)compr[method].argv);
438 (void)fprintf(stderr, "exec `%s' failed (%s)\n",
439 compr[method].argv[0], strerror(errno));
444 file_error(ms, errno, "could not fork");
447 default: /* parent */
448 (void) close(fdout[1]);
450 (void) close(fdin[0]);
452 * fork again, to avoid blocking because both
457 (void)close(fdout[0]);
458 if (swrite(fdin[1], old, n) != (ssize_t)n) {
460 (void)fprintf(stderr,
461 "Write failed (%s)\n",
471 (void)fprintf(stderr, "Fork failed (%s)\n",
477 default: /* parent */
478 if (wait(&status) == -1) {
480 (void)fprintf(stderr,
481 "Wait failed (%s)\n",
486 exit(WIFEXITED(status) ?
487 WEXITSTATUS(status) : 1);
490 (void) close(fdin[1]);
494 if ((*newch = (unsigned char *) malloc(HOWMANY + 1)) == NULL) {
496 (void)fprintf(stderr, "Malloc failed (%s)\n",
502 if ((r = sread(fdout[0], *newch, HOWMANY, 0)) <= 0) {
504 (void)fprintf(stderr, "Read failed (%s)\n",
514 /* NUL terminate, as every buffer is handled here. */
518 (void) close(fdin[1]);
519 (void) close(fdout[0]);
520 if (wait(&status) == -1) {
522 (void)fprintf(stderr, "Wait failed (%s)\n",
526 } else if (!WIFEXITED(status)) {
528 (void)fprintf(stderr, "Child not exited (0x%x)\n",
531 } else if (WEXITSTATUS(status) != 0) {
533 (void)fprintf(stderr, "Child exited (0x%d)\n",
534 WEXITSTATUS(status));
538 (void) close(fdin[0]);