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 1.67 2011/09/01 12:12:37 christos Exp $")
49 #include <sys/ioctl.h>
51 #ifdef HAVE_SYS_WAIT_H
54 #if defined(HAVE_SYS_TIME_H)
57 #if defined(HAVE_ZLIB_H) && defined(HAVE_LIBZ)
58 #define BUILTIN_DECOMPRESS
62 private const struct {
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 */
77 { "PK\3\4", 4, { "gzip", "-cdq", NULL }, 1 }, /* pkzipped, */
78 /* ...only first file examined */
79 { "BZh", 3, { "bzip2", "-cd", NULL }, 1 }, /* bzip2-ed */
80 { "LZIP", 4, { "lzip", "-cdq", NULL }, 1 },
81 { "\3757zXZ\0",6,{ "xz", "-cd", NULL }, 1 }, /* XZ Utils */
82 { "LRZI", 4, { "lrzip", "-dqo-", NULL }, 1 }, /* LRZIP */
85 #define NODATA ((size_t)~0)
87 private ssize_t swrite(int, const void *, size_t);
89 private size_t ncompr = sizeof(compr) / sizeof(compr[0]);
90 private size_t uncompressbuf(struct magic_set *, int, size_t,
91 const unsigned char *, unsigned char **, size_t);
92 #ifdef BUILTIN_DECOMPRESS
93 private size_t uncompressgzipped(struct magic_set *, const unsigned char *,
94 unsigned char **, size_t);
98 file_zmagic(struct magic_set *ms, int fd, const char *name,
99 const unsigned char *buf, size_t nbytes)
101 unsigned char *newbuf = NULL;
104 int mime = ms->flags & MAGIC_MIME;
106 if ((ms->flags & MAGIC_COMPRESS) == 0)
109 for (i = 0; i < ncompr; i++) {
110 if (nbytes < compr[i].maglen)
112 if (memcmp(buf, compr[i].magic, compr[i].maglen) == 0 &&
113 (nsz = uncompressbuf(ms, fd, i, buf, &newbuf,
114 nbytes)) != NODATA) {
115 ms->flags &= ~MAGIC_COMPRESS;
117 if (file_buffer(ms, -1, name, newbuf, nsz) == -1)
120 if (mime == MAGIC_MIME || mime == 0) {
121 if (file_printf(ms, mime ?
122 " compressed-encoding=" : " (") == -1)
126 if ((mime == 0 || mime & MAGIC_MIME_ENCODING) &&
127 file_buffer(ms, -1, NULL, buf, nbytes) == -1)
130 if (!mime && file_printf(ms, ")") == -1)
139 ms->flags |= MAGIC_COMPRESS;
144 * `safe' write for sockets and pipes.
147 swrite(int fd, const void *buf, size_t n)
153 switch (rv = write(fd, buf, n)) {
160 buf = CAST(const char *, buf) + rv;
169 * `safe' read for sockets and pipes.
172 sread(int fd, void *buf, size_t n, int canbepipe __attribute__ ((unused)))
183 if (fd == STDIN_FILENO)
187 if ((canbepipe && (ioctl(fd, FIONREAD, &t) == -1)) || (t == 0)) {
189 for (cnt = 0;; cnt++) {
191 struct timeval tout = {0, 100 * 1000};
198 * Avoid soft deadlock: do not read if there
199 * is nothing to read from sockets and pipes.
201 selrv = select(fd + 1, &check, NULL, NULL, &tout);
203 if (errno == EINTR || errno == EAGAIN)
205 } else if (selrv == 0 && cnt >= 5) {
211 (void)ioctl(fd, FIONREAD, &t);
214 if (t > 0 && (size_t)t < n) {
222 switch ((rv = read(fd, buf, n))) {
231 buf = ((char *)buf) + rv;
239 file_pipe2file(struct magic_set *ms, int fd, const void *startbuf,
249 (void)strlcpy(buf, "/tmp/file.XXXXXX", sizeof buf);
252 char *ptr = mktemp(buf);
253 tfd = open(ptr, O_RDWR|O_TRUNC|O_EXCL|O_CREAT, 0600);
265 file_error(ms, errno,
266 "cannot create temporary file for pipe copy");
270 if (swrite(tfd, startbuf, nbytes) != (ssize_t)nbytes)
273 while ((r = sread(fd, buf, sizeof(buf), 1)) > 0)
274 if (swrite(tfd, buf, (size_t)r) != r)
280 file_error(ms, errno, "error copying from pipe to temp file");
285 file_error(ms, errno, "error while writing to temp file");
290 * We duplicate the file descriptor, because fclose on a
291 * tmpfile will delete the file, but any open descriptors
292 * can still access the phantom inode.
294 if ((fd = dup2(tfd, fd)) == -1) {
295 file_error(ms, errno, "could not dup descriptor for temp file");
299 if (lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) {
306 #ifdef BUILTIN_DECOMPRESS
308 #define FHCRC (1 << 1)
309 #define FEXTRA (1 << 2)
310 #define FNAME (1 << 3)
311 #define FCOMMENT (1 << 4)
314 uncompressgzipped(struct magic_set *ms, const unsigned char *old,
315 unsigned char **newch, size_t n)
317 unsigned char flg = old[3];
318 size_t data_start = 10;
323 if (data_start+1 >= n)
325 data_start += 2 + old[data_start] + old[data_start + 1] * 256;
328 while(data_start < n && old[data_start])
333 while(data_start < n && old[data_start])
342 if ((*newch = CAST(unsigned char *, malloc(HOWMANY + 1))) == NULL) {
346 /* XXX: const castaway, via strchr */
347 z.next_in = (Bytef *)strchr((const char *)old + data_start,
349 z.avail_in = CAST(uint32_t, (n - data_start));
351 z.avail_out = HOWMANY;
356 /* LINTED bug in header macro */
357 rc = inflateInit2(&z, -15);
359 file_error(ms, 0, "zlib: %s", z.msg);
363 rc = inflate(&z, Z_SYNC_FLUSH);
364 if (rc != Z_OK && rc != Z_STREAM_END) {
365 file_error(ms, 0, "zlib: %s", z.msg);
369 n = (size_t)z.total_out;
370 (void)inflateEnd(&z);
372 /* let's keep the nul-terminate tradition */
380 uncompressbuf(struct magic_set *ms, int fd, size_t method,
381 const unsigned char *old, unsigned char **newch, size_t n)
383 int fdin[2], fdout[2];
387 #ifdef BUILTIN_DECOMPRESS
388 /* FIXME: This doesn't cope with bzip2 */
390 return uncompressgzipped(ms, old, newch, n);
392 (void)fflush(stdout);
393 (void)fflush(stderr);
395 if ((fd != -1 && pipe(fdin) == -1) || pipe(fdout) == -1) {
396 file_error(ms, errno, "cannot create pipe");
399 switch (pid = fork()) {
404 (void) lseek(0, (off_t)0, SEEK_SET);
407 (void) close(fdin[0]);
408 (void) close(fdin[1]);
412 (void) dup(fdout[1]);
413 (void) close(fdout[0]);
414 (void) close(fdout[1]);
416 if (compr[method].silent)
420 (void)execvp(compr[method].argv[0],
421 (char *const *)(intptr_t)compr[method].argv);
423 (void)fprintf(stderr, "exec `%s' failed (%s)\n",
424 compr[method].argv[0], strerror(errno));
429 file_error(ms, errno, "could not fork");
432 default: /* parent */
433 (void) close(fdout[1]);
435 (void) close(fdin[0]);
437 * fork again, to avoid blocking because both
442 (void)close(fdout[0]);
443 if (swrite(fdin[1], old, n) != (ssize_t)n) {
445 (void)fprintf(stderr,
446 "Write failed (%s)\n",
456 (void)fprintf(stderr, "Fork failed (%s)\n",
462 default: /* parent */
465 (void) close(fdin[1]);
469 if ((*newch = (unsigned char *) malloc(HOWMANY + 1)) == NULL) {
471 (void)fprintf(stderr, "Malloc failed (%s)\n",
477 if ((r = sread(fdout[0], *newch, HOWMANY, 0)) <= 0) {
479 (void)fprintf(stderr, "Read failed (%s)\n",
489 /* NUL terminate, as every buffer is handled here. */
493 (void) close(fdin[1]);
494 (void) close(fdout[0]);
496 while (waitpid(pid, NULL, WNOHANG) != -1)
501 (void) close(fdin[0]);