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 #ifdef HAVE_SYS_WAIT_H
53 FILE_RCSID("@(#)$Id: compress.c,v 1.38 2004/09/11 19:15:57 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 { "BZh", 3, { "bzip2", "-cd", NULL }, 1 }, /* bzip2-ed */
75 private int ncompr = sizeof(compr) / sizeof(compr[0]);
78 private ssize_t swrite(int, const void *, size_t);
79 private ssize_t sread(int, void *, size_t);
80 private size_t uncompressbuf(struct magic_set *, size_t, const unsigned char *,
81 unsigned char **, size_t);
83 private size_t uncompressgzipped(struct magic_set *, const unsigned char *,
84 unsigned char **, size_t);
88 file_zmagic(struct magic_set *ms, const unsigned char *buf, size_t nbytes)
90 unsigned char *newbuf = NULL;
94 if ((ms->flags & MAGIC_COMPRESS) == 0)
97 for (i = 0; i < ncompr; i++) {
98 if (nbytes < compr[i].maglen)
100 if (memcmp(buf, compr[i].magic, compr[i].maglen) == 0 &&
101 (nsz = uncompressbuf(ms, i, buf, &newbuf, nbytes)) != 0) {
102 ms->flags &= ~MAGIC_COMPRESS;
104 if (file_buffer(ms, newbuf, nsz) == -1)
106 if (file_printf(ms, " (") == -1)
108 if (file_buffer(ms, buf, nbytes) == -1)
110 if (file_printf(ms, ")") == -1)
119 ms->flags |= MAGIC_COMPRESS;
124 * `safe' write for sockets and pipes.
127 swrite(int fd, const void *buf, size_t n)
133 switch (rv = write(fd, buf, n)) {
140 buf = ((const char *)buf) + rv;
149 * `safe' read for sockets and pipes.
152 sread(int fd, void *buf, size_t n)
158 switch (rv = read(fd, buf, n)) {
167 buf = ((char *)buf) + rv;
175 file_pipe2file(struct magic_set *ms, int fd, const void *startbuf,
181 (void)strcpy(buf, "/tmp/file.XXXXXX");
184 char *ptr = mktemp(buf);
185 tfd = open(ptr, O_RDWR|O_TRUNC|O_EXCL|O_CREAT, 0600);
197 file_error(ms, errno,
198 "cannot create temporary file for pipe copy");
202 if (swrite(tfd, startbuf, nbytes) != (ssize_t)nbytes)
205 while ((r = sread(fd, buf, sizeof(buf))) > 0)
206 if (swrite(tfd, buf, (size_t)r) != r)
212 file_error(ms, errno, "error copying from pipe to temp file");
217 file_error(ms, errno, "error while writing to temp file");
222 * We duplicate the file descriptor, because fclose on a
223 * tmpfile will delete the file, but any open descriptors
224 * can still access the phantom inode.
226 if ((fd = dup2(tfd, fd)) == -1) {
227 file_error(ms, errno, "could not dup descriptor for temp file");
231 if (lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) {
240 #define FHCRC (1 << 1)
241 #define FEXTRA (1 << 2)
242 #define FNAME (1 << 3)
243 #define FCOMMENT (1 << 4)
246 uncompressgzipped(struct magic_set *ms, const unsigned char *old,
247 unsigned char **newch, size_t n)
249 unsigned char flg = old[3];
250 size_t data_start = 10;
255 if (data_start+1 >= n)
257 data_start += 2 + old[data_start] + old[data_start + 1] * 256;
260 while(data_start < n && old[data_start])
265 while(data_start < n && old[data_start])
274 if ((*newch = (unsigned char *)malloc(HOWMANY + 1)) == NULL) {
278 /* XXX: const castaway, via strchr */
279 z.next_in = (Bytef *)strchr((const char *)old + data_start,
281 z.avail_in = n - data_start;
283 z.avail_out = HOWMANY;
288 rc = inflateInit2(&z, -15);
290 file_error(ms, 0, "zlib: %s", z.msg);
294 rc = inflate(&z, Z_SYNC_FLUSH);
295 if (rc != Z_OK && rc != Z_STREAM_END) {
296 file_error(ms, 0, "zlib: %s", z.msg);
300 n = (size_t)z.total_out;
303 /* let's keep the nul-terminate tradition */
304 (*newch)[n++] = '\0';
311 uncompressbuf(struct magic_set *ms, size_t method, const unsigned char *old,
312 unsigned char **newch, size_t n)
314 int fdin[2], fdout[2];
317 /* The buffer is NUL terminated, and we don't need that. */
322 return uncompressgzipped(ms, old, newch, n);
325 if (pipe(fdin) == -1 || pipe(fdout) == -1) {
326 file_error(ms, errno, "cannot create pipe");
333 (void) close(fdin[0]);
334 (void) close(fdin[1]);
337 (void) dup(fdout[1]);
338 (void) close(fdout[0]);
339 (void) close(fdout[1]);
340 if (compr[method].silent)
343 execvp(compr[method].argv[0],
344 (char *const *)compr[method].argv);
348 file_error(ms, errno, "could not fork");
351 default: /* parent */
352 (void) close(fdin[0]);
353 (void) close(fdout[1]);
354 /* fork again, to avoid blocking because both pipes filled */
357 (void)close(fdout[0]);
358 if (swrite(fdin[1], old, n) != n)
367 default: /* parent */
370 (void) close(fdin[1]);
372 if ((*newch = (unsigned char *) malloc(HOWMANY + 1)) == NULL) {
376 if ((r = sread(fdout[0], *newch, HOWMANY)) <= 0) {
384 /* NUL terminate, as every buffer is handled here. */
385 (*newch)[n++] = '\0';
388 (void) close(fdin[1]);
389 (void) close(fdout[0]);
391 while (waitpid(-1, NULL, WNOHANG) != -1)