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 1.63 2009/03/23 14:21:51 christos Exp $")
48 #include <sys/ioctl.h>
49 #ifdef HAVE_SYS_WAIT_H
52 #if defined(HAVE_SYS_TIME_H)
55 #if defined(HAVE_ZLIB_H) && defined(HAVE_LIBZ)
56 #define BUILTIN_DECOMPRESS
60 private const struct {
66 { "\037\235", 2, { "gzip", "-cdq", NULL }, 1 }, /* compressed */
67 /* Uncompress can get stuck; so use gzip first if we have it
68 * Idea from Damien Clark, thanks! */
69 { "\037\235", 2, { "uncompress", "-c", NULL }, 1 }, /* compressed */
70 { "\037\213", 2, { "gzip", "-cdq", NULL }, 1 }, /* gzipped */
71 { "\037\236", 2, { "gzip", "-cdq", NULL }, 1 }, /* frozen */
72 { "\037\240", 2, { "gzip", "-cdq", NULL }, 1 }, /* SCO LZH */
73 /* the standard pack utilities do not accept standard input */
74 { "\037\036", 2, { "gzip", "-cdq", NULL }, 0 }, /* packed */
75 { "PK\3\4", 4, { "gzip", "-cdq", NULL }, 1 }, /* pkzipped, */
76 /* ...only first file examined */
77 { "BZh", 3, { "bzip2", "-cd", NULL }, 1 }, /* bzip2-ed */
78 { "LZIP", 4, { "lzip", "-cdq", NULL }, 1 },
79 { "\3757zXZ\0",6,{ "xz", "-cd", NULL }, 1 }, /* XZ Utils */
82 private size_t ncompr = sizeof(compr) / sizeof(compr[0]);
84 #define NODATA ((size_t)~0)
87 private ssize_t swrite(int, const void *, size_t);
88 private size_t uncompressbuf(struct magic_set *, int, size_t,
89 const unsigned char *, unsigned char **, size_t);
90 #ifdef BUILTIN_DECOMPRESS
91 private size_t uncompressgzipped(struct magic_set *, const unsigned char *,
92 unsigned char **, size_t);
96 file_zmagic(struct magic_set *ms, int fd, const char *name,
97 const unsigned char *buf, size_t nbytes)
99 unsigned char *newbuf = NULL;
102 int mime = ms->flags & MAGIC_MIME;
104 if ((ms->flags & MAGIC_COMPRESS) == 0)
107 for (i = 0; i < ncompr; i++) {
108 if (nbytes < compr[i].maglen)
110 if (memcmp(buf, compr[i].magic, compr[i].maglen) == 0 &&
111 (nsz = uncompressbuf(ms, fd, i, buf, &newbuf,
112 nbytes)) != NODATA) {
113 ms->flags &= ~MAGIC_COMPRESS;
115 if (file_buffer(ms, -1, name, newbuf, nsz) == -1)
118 if (mime == MAGIC_MIME || mime == 0) {
119 if (file_printf(ms, mime ?
120 " compressed-encoding=" : " (") == -1)
124 if ((mime == 0 || mime & MAGIC_MIME_ENCODING) &&
125 file_buffer(ms, -1, NULL, buf, nbytes) == -1)
128 if (!mime && file_printf(ms, ")") == -1)
137 ms->flags |= MAGIC_COMPRESS;
142 * `safe' write for sockets and pipes.
145 swrite(int fd, const void *buf, size_t n)
151 switch (rv = write(fd, buf, n)) {
158 buf = ((const char *)buf) + rv;
167 * `safe' read for sockets and pipes.
170 sread(int fd, void *buf, size_t n, int canbepipe)
178 if (fd == STDIN_FILENO)
182 if ((canbepipe && (ioctl(fd, FIONREAD, &t) == -1)) || (t == 0)) {
184 for (cnt = 0;; cnt++) {
186 struct timeval tout = {0, 100 * 1000};
193 * Avoid soft deadlock: do not read if there
194 * is nothing to read from sockets and pipes.
196 selrv = select(fd + 1, &check, NULL, NULL, &tout);
198 if (errno == EINTR || errno == EAGAIN)
200 } else if (selrv == 0 && cnt >= 5) {
206 (void)ioctl(fd, FIONREAD, &t);
209 if (t > 0 && (size_t)t < n) {
217 switch ((rv = read(fd, buf, n))) {
226 buf = ((char *)buf) + rv;
234 file_pipe2file(struct magic_set *ms, int fd, const void *startbuf,
240 (void)strlcpy(buf, "/tmp/file.XXXXXX", sizeof buf);
243 char *ptr = mktemp(buf);
244 tfd = open(ptr, O_RDWR|O_TRUNC|O_EXCL|O_CREAT, 0600);
256 file_error(ms, errno,
257 "cannot create temporary file for pipe copy");
261 if (swrite(tfd, startbuf, nbytes) != (ssize_t)nbytes)
264 while ((r = sread(fd, buf, sizeof(buf), 1)) > 0)
265 if (swrite(tfd, buf, (size_t)r) != r)
271 file_error(ms, errno, "error copying from pipe to temp file");
276 file_error(ms, errno, "error while writing to temp file");
281 * We duplicate the file descriptor, because fclose on a
282 * tmpfile will delete the file, but any open descriptors
283 * can still access the phantom inode.
285 if ((fd = dup2(tfd, fd)) == -1) {
286 file_error(ms, errno, "could not dup descriptor for temp file");
290 if (lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) {
297 #ifdef BUILTIN_DECOMPRESS
299 #define FHCRC (1 << 1)
300 #define FEXTRA (1 << 2)
301 #define FNAME (1 << 3)
302 #define FCOMMENT (1 << 4)
305 uncompressgzipped(struct magic_set *ms, const unsigned char *old,
306 unsigned char **newch, size_t n)
308 unsigned char flg = old[3];
309 size_t data_start = 10;
314 if (data_start+1 >= n)
316 data_start += 2 + old[data_start] + old[data_start + 1] * 256;
319 while(data_start < n && old[data_start])
324 while(data_start < n && old[data_start])
333 if ((*newch = CAST(unsigned char *, malloc(HOWMANY + 1))) == NULL) {
337 /* XXX: const castaway, via strchr */
338 z.next_in = (Bytef *)strchr((const char *)old + data_start,
340 z.avail_in = n - data_start;
342 z.avail_out = HOWMANY;
347 rc = inflateInit2(&z, -15);
349 file_error(ms, 0, "zlib: %s", z.msg);
353 rc = inflate(&z, Z_SYNC_FLUSH);
354 if (rc != Z_OK && rc != Z_STREAM_END) {
355 file_error(ms, 0, "zlib: %s", z.msg);
359 n = (size_t)z.total_out;
360 (void)inflateEnd(&z);
362 /* let's keep the nul-terminate tradition */
370 uncompressbuf(struct magic_set *ms, int fd, size_t method,
371 const unsigned char *old, unsigned char **newch, size_t n)
373 int fdin[2], fdout[2];
376 #ifdef BUILTIN_DECOMPRESS
377 /* FIXME: This doesn't cope with bzip2 */
379 return uncompressgzipped(ms, old, newch, n);
381 (void)fflush(stdout);
382 (void)fflush(stderr);
384 if ((fd != -1 && pipe(fdin) == -1) || pipe(fdout) == -1) {
385 file_error(ms, errno, "cannot create pipe");
393 (void) lseek(0, (off_t)0, SEEK_SET);
396 (void) close(fdin[0]);
397 (void) close(fdin[1]);
401 (void) dup(fdout[1]);
402 (void) close(fdout[0]);
403 (void) close(fdout[1]);
405 if (compr[method].silent)
409 (void)execvp(compr[method].argv[0],
410 (char *const *)(intptr_t)compr[method].argv);
412 (void)fprintf(stderr, "exec `%s' failed (%s)\n",
413 compr[method].argv[0], strerror(errno));
418 file_error(ms, errno, "could not fork");
421 default: /* parent */
422 (void) close(fdout[1]);
424 (void) close(fdin[0]);
426 * fork again, to avoid blocking because both
431 (void)close(fdout[0]);
432 if (swrite(fdin[1], old, n) != (ssize_t)n) {
434 (void)fprintf(stderr,
435 "Write failed (%s)\n",
445 (void)fprintf(stderr, "Fork failed (%s)\n",
451 default: /* parent */
454 (void) close(fdin[1]);
458 if ((*newch = (unsigned char *) malloc(HOWMANY + 1)) == NULL) {
460 (void)fprintf(stderr, "Malloc failed (%s)\n",
466 if ((r = sread(fdout[0], *newch, HOWMANY, 0)) <= 0) {
468 (void)fprintf(stderr, "Read failed (%s)\n",
478 /* NUL terminate, as every buffer is handled here. */
482 (void) close(fdin[1]);
483 (void) close(fdout[0]);
485 while (waitpid(-1, NULL, WNOHANG) != -1)
490 (void) close(fdin[0]);