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
29 * fsmagic - magic based on filesystem info - directory, special files, etc.
35 FILE_RCSID("@(#)$File: fsmagic.c,v 1.64 2011/08/14 09:03:12 christos Exp $")
44 /* Since major is a function on SVR4, we cannot use `ifndef major'. */
46 # include <sys/mkdev.h>
49 #ifdef MAJOR_IN_SYSMACROS
50 # include <sys/sysmacros.h>
53 #ifdef major /* Might be defined in sys/types.h. */
58 # define major(dev) (((dev) >> 8) & 0xff)
59 # define minor(dev) ((dev) & 0xff)
64 bad_link(struct magic_set *ms, int err, char *buf)
66 int mime = ms->flags & MAGIC_MIME;
67 if ((mime & MAGIC_MIME_TYPE) &&
68 file_printf(ms, "inode/symlink")
72 if (ms->flags & MAGIC_ERROR) {
74 "broken symbolic link to `%s'", buf);
77 if (file_printf(ms, "broken symbolic link to `%s'", buf) == -1)
84 handle_mime(struct magic_set *ms, int mime, const char *str)
86 if ((mime & MAGIC_MIME_TYPE)) {
87 if (file_printf(ms, "inode/%s", str) == -1)
89 if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms,
93 if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms, "binary") == -1)
99 file_fsmagic(struct magic_set *ms, const char *fn, struct stat *sb)
102 int mime = ms->flags & MAGIC_MIME;
106 struct stat tstatbuf;
109 if (ms->flags & MAGIC_APPLE)
115 * Fstat is cheaper but fails for files you don't have read perms on.
116 * On 4.2BSD and similar systems, use lstat() to identify symlinks.
119 if ((ms->flags & MAGIC_SYMLINK) == 0)
123 ret = stat(fn, sb); /* don't merge into if; see "ret =" above */
126 if (ms->flags & MAGIC_ERROR) {
127 file_error(ms, errno, "cannot stat `%s'", fn);
130 if (file_printf(ms, "cannot open `%s' (%s)",
131 fn, strerror(errno)) == -1)
133 ms->event_flags |= EVENT_HAD_ERR;
139 if (sb->st_mode & S_ISUID)
140 if (file_printf(ms, "setuid ") == -1)
144 if (sb->st_mode & S_ISGID)
145 if (file_printf(ms, "setgid ") == -1)
149 if (sb->st_mode & S_ISVTX)
150 if (file_printf(ms, "sticky ") == -1)
155 switch (sb->st_mode & S_IFMT) {
158 if (handle_mime(ms, mime, "directory") == -1)
160 } else if (file_printf(ms, "directory") == -1)
166 * If -s has been specified, treat character special files
167 * like ordinary files. Otherwise, just report that they
168 * are block special files and go on to the next file.
170 if ((ms->flags & MAGIC_DEVICES) != 0)
173 if (handle_mime(ms, mime, "chardevice") == -1)
176 #ifdef HAVE_STAT_ST_RDEV
178 if (file_printf(ms, "character special (%d/%d/%d)",
179 major(sb->st_rdev), dv_unit(sb->st_rdev),
180 dv_subunit(sb->st_rdev)) == -1)
183 if (file_printf(ms, "character special (%ld/%ld)",
184 (long)major(sb->st_rdev), (long)minor(sb->st_rdev))
189 if (file_printf(ms, "character special") == -1)
198 * If -s has been specified, treat block special files
199 * like ordinary files. Otherwise, just report that they
200 * are block special files and go on to the next file.
202 if ((ms->flags & MAGIC_DEVICES) != 0)
205 if (handle_mime(ms, mime, "blockdevice") == -1)
208 #ifdef HAVE_STAT_ST_RDEV
210 if (file_printf(ms, "block special (%d/%d/%d)",
211 major(sb->st_rdev), dv_unit(sb->st_rdev),
212 dv_subunit(sb->st_rdev)) == -1)
215 if (file_printf(ms, "block special (%ld/%ld)",
216 (long)major(sb->st_rdev), (long)minor(sb->st_rdev)) == -1)
220 if (file_printf(ms, "block special") == -1)
226 /* TODO add code to handle V7 MUX and Blit MUX files */
229 if((ms->flags & MAGIC_DEVICES) != 0)
232 if (handle_mime(ms, mime, "fifo") == -1)
234 } else if (file_printf(ms, "fifo (named pipe)") == -1)
241 if (handle_mime(ms, mime, "door") == -1)
243 } else if (file_printf(ms, "door") == -1)
249 if ((nch = readlink(fn, buf, BUFSIZ-1)) <= 0) {
250 if (ms->flags & MAGIC_ERROR) {
251 file_error(ms, errno, "unreadable symlink `%s'",
256 if (handle_mime(ms, mime, "symlink") == -1)
258 } else if (file_printf(ms,
259 "unreadable symlink `%s' (%s)", fn,
260 strerror(errno)) == -1)
264 buf[nch] = '\0'; /* readlink(2) does not do this */
266 /* If broken symlink, say so and quit early. */
268 if (stat(buf, &tstatbuf) < 0)
269 return bad_link(ms, errno, buf);
272 char buf2[BUFSIZ+BUFSIZ+4];
274 if ((tmp = strrchr(fn, '/')) == NULL) {
275 tmp = buf; /* in current directory anyway */
277 if (tmp - fn + 1 > BUFSIZ) {
278 if (ms->flags & MAGIC_ERROR) {
280 "path too long: `%s'", buf);
284 if (handle_mime(ms, mime,
285 "x-path-too-long") == -1)
287 } else if (file_printf(ms,
288 "path too long: `%s'", fn) == -1)
293 (void)strlcpy(buf2, fn, sizeof buf2);
294 buf2[tmp - fn + 1] = '\0';
295 /* plus (rel) link */
296 (void)strlcat(buf2, buf, sizeof buf2);
299 if (stat(tmp, &tstatbuf) < 0)
300 return bad_link(ms, errno, buf);
303 /* Otherwise, handle it. */
304 if ((ms->flags & MAGIC_SYMLINK) != 0) {
306 ms->flags &= MAGIC_SYMLINK;
307 p = magic_file(ms, buf);
308 ms->flags |= MAGIC_SYMLINK;
309 return p != NULL ? 1 : -1;
310 } else { /* just print what it points to */
312 if (handle_mime(ms, mime, "symlink") == -1)
314 } else if (file_printf(ms, "symbolic link to `%s'",
324 if (handle_mime(ms, mime, "socket") == -1)
326 } else if (file_printf(ms, "socket") == -1)
334 file_error(ms, 0, "invalid mode 0%o", sb->st_mode);
340 * regular file, check next possibility
342 * If stat() tells us the file has zero length, report here that
343 * the file is empty, so we can skip all the work of opening and
345 * But if the -s option has been given, we skip this optimization,
346 * since on some systems, stat() reports zero size for raw disk
347 * partitions. (If the block special device really has zero length,
348 * the fact that it is empty will be detected and reported correctly
349 * when we read the file.)
351 if ((ms->flags & MAGIC_DEVICES) == 0 && sb->st_size == 0) {
353 if (handle_mime(ms, mime, "x-empty") == -1)
355 } else if (file_printf(ms, "empty") == -1)