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
44 #include <sys/types.h>
45 #include <sys/ioctl.h>
46 #ifdef HAVE_SYS_WAIT_H
54 FILE_RCSID("@(#)$Id: compress.c,v 1.45 2006/10/31 19:37:17 christos Exp $")
60 const char *const argv[3];
63 { "\037\235", 2, { "gzip", "-cdq", NULL }, 1 }, /* compressed */
64 /* Uncompress can get stuck; so use gzip first if we have it
65 * Idea from Damien Clark, thanks! */
66 { "\037\235", 2, { "uncompress", "-c", NULL }, 1 }, /* compressed */
67 { "\037\213", 2, { "gzip", "-cdq", NULL }, 1 }, /* gzipped */
68 { "\037\236", 2, { "gzip", "-cdq", NULL }, 1 }, /* frozen */
69 { "\037\240", 2, { "gzip", "-cdq", NULL }, 1 }, /* SCO LZH */
70 /* the standard pack utilities do not accept standard input */
71 { "\037\036", 2, { "gzip", "-cdq", NULL }, 0 }, /* packed */
72 { "PK\3\4", 4, { "gzip", "-cdq", NULL }, 1 }, /* pkzipped, */
73 /* ...only first file examined */
74 { "BZh", 3, { "bzip2", "-cd", NULL }, 1 }, /* bzip2-ed */
77 private int ncompr = sizeof(compr) / sizeof(compr[0]);
79 #define NODATA ((size_t)~0)
82 private ssize_t swrite(int, const void *, size_t);
83 private size_t uncompressbuf(struct magic_set *, int, size_t,
84 const unsigned char *, unsigned char **, size_t);
86 private size_t uncompressgzipped(struct magic_set *, const unsigned char *,
87 unsigned char **, size_t);
91 file_zmagic(struct magic_set *ms, int fd, const unsigned char *buf,
94 unsigned char *newbuf = NULL;
98 if ((ms->flags & MAGIC_COMPRESS) == 0)
101 for (i = 0; i < ncompr; i++) {
102 if (nbytes < compr[i].maglen)
104 if (memcmp(buf, compr[i].magic, compr[i].maglen) == 0 &&
105 (nsz = uncompressbuf(ms, fd, i, buf, &newbuf,
106 nbytes)) != NODATA) {
107 ms->flags &= ~MAGIC_COMPRESS;
109 if (file_buffer(ms, -1, newbuf, nsz) == -1)
111 if (file_printf(ms, " (") == -1)
113 if (file_buffer(ms, -1, buf, nbytes) == -1)
115 if (file_printf(ms, ")") == -1)
124 ms->flags |= MAGIC_COMPRESS;
129 * `safe' write for sockets and pipes.
132 swrite(int fd, const void *buf, size_t n)
138 switch (rv = write(fd, buf, n)) {
145 buf = ((const char *)buf) + rv;
154 * `safe' read for sockets and pipes.
157 sread(int fd, void *buf, size_t n)
165 if (fd == STDIN_FILENO)
169 if ((ioctl(fd, FIONREAD, &t) < 0) || (t == 0)) {
173 struct timeval tout = {0, 100 * 1000};
179 * Avoid soft deadlock: do not read if there
180 * is nothing to read from sockets and pipes.
182 if (select(fd + 1, &check, NULL, NULL, &tout) <= 0) {
183 if (errno == EINTR || errno == EAGAIN)
190 (void)ioctl(fd, FIONREAD, &t);
193 if (t > 0 && (size_t)t < n) {
201 switch ((rv = read(fd, buf, n))) {
210 buf = ((char *)buf) + rv;
218 file_pipe2file(struct magic_set *ms, int fd, const void *startbuf,
224 (void)strcpy(buf, "/tmp/file.XXXXXX");
227 char *ptr = mktemp(buf);
228 tfd = open(ptr, O_RDWR|O_TRUNC|O_EXCL|O_CREAT, 0600);
240 file_error(ms, errno,
241 "cannot create temporary file for pipe copy");
245 if (swrite(tfd, startbuf, nbytes) != (ssize_t)nbytes)
248 while ((r = sread(fd, buf, sizeof(buf))) > 0)
249 if (swrite(tfd, buf, (size_t)r) != r)
255 file_error(ms, errno, "error copying from pipe to temp file");
260 file_error(ms, errno, "error while writing to temp file");
265 * We duplicate the file descriptor, because fclose on a
266 * tmpfile will delete the file, but any open descriptors
267 * can still access the phantom inode.
269 if ((fd = dup2(tfd, fd)) == -1) {
270 file_error(ms, errno, "could not dup descriptor for temp file");
274 if (lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) {
283 #define FHCRC (1 << 1)
284 #define FEXTRA (1 << 2)
285 #define FNAME (1 << 3)
286 #define FCOMMENT (1 << 4)
289 uncompressgzipped(struct magic_set *ms, const unsigned char *old,
290 unsigned char **newch, size_t n)
292 unsigned char flg = old[3];
293 size_t data_start = 10;
298 if (data_start+1 >= n)
300 data_start += 2 + old[data_start] + old[data_start + 1] * 256;
303 while(data_start < n && old[data_start])
308 while(data_start < n && old[data_start])
317 if ((*newch = (unsigned char *)malloc(HOWMANY + 1)) == NULL) {
321 /* XXX: const castaway, via strchr */
322 z.next_in = (Bytef *)strchr((const char *)old + data_start,
324 z.avail_in = n - data_start;
326 z.avail_out = HOWMANY;
331 rc = inflateInit2(&z, -15);
333 file_error(ms, 0, "zlib: %s", z.msg);
337 rc = inflate(&z, Z_SYNC_FLUSH);
338 if (rc != Z_OK && rc != Z_STREAM_END) {
339 file_error(ms, 0, "zlib: %s", z.msg);
343 n = (size_t)z.total_out;
346 /* let's keep the nul-terminate tradition */
354 uncompressbuf(struct magic_set *ms, int fd, size_t method,
355 const unsigned char *old, unsigned char **newch, size_t n)
357 int fdin[2], fdout[2];
362 return uncompressgzipped(ms, old, newch, n);
364 (void)fflush(stdout);
365 (void)fflush(stderr);
367 if ((fd != -1 && pipe(fdin) == -1) || pipe(fdout) == -1) {
368 file_error(ms, errno, "cannot create pipe");
376 (void) lseek(0, (off_t)0, SEEK_SET);
379 (void) close(fdin[0]);
380 (void) close(fdin[1]);
384 (void) dup(fdout[1]);
385 (void) close(fdout[0]);
386 (void) close(fdout[1]);
388 if (compr[method].silent)
392 execvp(compr[method].argv[0],
393 (char *const *)(intptr_t)compr[method].argv);
395 (void)fprintf(stderr, "exec `%s' failed (%s)\n",
396 compr[method].argv[0], strerror(errno));
401 file_error(ms, errno, "could not fork");
404 default: /* parent */
405 (void) close(fdout[1]);
407 (void) close(fdin[0]);
409 * fork again, to avoid blocking because both
414 (void)close(fdout[0]);
415 if (swrite(fdin[1], old, n) != n) {
417 (void)fprintf(stderr,
418 "Write failed (%s)\n",
428 (void)fprintf(stderr, "Fork failed (%s)\n",
434 default: /* parent */
437 (void) close(fdin[1]);
441 if ((*newch = (unsigned char *) malloc(HOWMANY + 1)) == NULL) {
443 (void)fprintf(stderr, "Malloc failed (%s)\n",
449 if ((r = sread(fdout[0], *newch, HOWMANY)) <= 0) {
451 (void)fprintf(stderr, "Read failed (%s)\n",
461 /* NUL terminate, as every buffer is handled here. */
465 (void) close(fdin[1]);
466 (void) close(fdout[0]);
468 while (waitpid(-1, NULL, WNOHANG) != -1)