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 1.59 2009/02/03 20:27:51 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)
67 int mime = ms->flags & MAGIC_MIME;
68 if ((mime & MAGIC_MIME_TYPE) &&
69 file_printf(ms, "application/x-symlink")
74 errfmt = "symbolic link in a loop";
76 errfmt = "broken symbolic link to `%s'";
77 if (ms->flags & MAGIC_ERROR) {
78 file_error(ms, err, errfmt, buf);
81 if (file_printf(ms, errfmt, buf) == -1)
88 handle_mime(struct magic_set *ms, int mime, const char *str)
90 if ((mime & MAGIC_MIME_TYPE)) {
91 if (file_printf(ms, "application/%s", str) == -1)
93 if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms,
97 if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms, "binary") == -1)
103 file_fsmagic(struct magic_set *ms, const char *fn, struct stat *sb)
106 int mime = ms->flags & MAGIC_MIME;
110 struct stat tstatbuf;
113 if (ms->flags & MAGIC_APPLE)
119 * Fstat is cheaper but fails for files you don't have read perms on.
120 * On 4.2BSD and similar systems, use lstat() to identify symlinks.
123 if ((ms->flags & MAGIC_SYMLINK) == 0)
127 ret = stat(fn, sb); /* don't merge into if; see "ret =" above */
130 if (ms->flags & MAGIC_ERROR) {
131 file_error(ms, errno, "cannot stat `%s'", fn);
134 if (file_printf(ms, "cannot open `%s' (%s)",
135 fn, strerror(errno)) == -1)
142 if (sb->st_mode & S_ISUID)
143 if (file_printf(ms, "setuid ") == -1)
147 if (sb->st_mode & S_ISGID)
148 if (file_printf(ms, "setgid ") == -1)
152 if (sb->st_mode & S_ISVTX)
153 if (file_printf(ms, "sticky ") == -1)
158 switch (sb->st_mode & S_IFMT) {
161 if (handle_mime(ms, mime, "x-directory") == -1)
163 } else if (file_printf(ms, "directory") == -1)
169 * If -s has been specified, treat character special files
170 * like ordinary files. Otherwise, just report that they
171 * are block special files and go on to the next file.
173 if ((ms->flags & MAGIC_DEVICES) != 0)
176 if (handle_mime(ms, mime, "x-character-device") == -1)
179 #ifdef HAVE_STAT_ST_RDEV
181 if (file_printf(ms, "character special (%d/%d/%d)",
182 major(sb->st_rdev), dv_unit(sb->st_rdev),
183 dv_subunit(sb->st_rdev)) == -1)
186 if (file_printf(ms, "character special (%ld/%ld)",
187 (long)major(sb->st_rdev), (long)minor(sb->st_rdev))
192 if (file_printf(ms, "character special") == -1)
201 * If -s has been specified, treat block special files
202 * like ordinary files. Otherwise, just report that they
203 * are block special files and go on to the next file.
205 if ((ms->flags & MAGIC_DEVICES) != 0)
208 if (handle_mime(ms, mime, "x-block-device") == -1)
211 #ifdef HAVE_STAT_ST_RDEV
213 if (file_printf(ms, "block special (%d/%d/%d)",
214 major(sb->st_rdev), dv_unit(sb->st_rdev),
215 dv_subunit(sb->st_rdev)) == -1)
218 if (file_printf(ms, "block special (%ld/%ld)",
219 (long)major(sb->st_rdev), (long)minor(sb->st_rdev)) == -1)
223 if (file_printf(ms, "block special") == -1)
229 /* TODO add code to handle V7 MUX and Blit MUX files */
232 if((ms->flags & MAGIC_DEVICES) != 0)
235 if (handle_mime(ms, mime, "x-fifo") == -1)
237 } else if (file_printf(ms, "fifo (named pipe)") == -1)
244 if (handle_mime(ms, mime, "x-door") == -1)
246 } else if (file_printf(ms, "door") == -1)
252 if ((nch = readlink(fn, buf, BUFSIZ-1)) <= 0) {
253 if (ms->flags & MAGIC_ERROR) {
254 file_error(ms, errno, "unreadable symlink `%s'",
259 if (handle_mime(ms, mime, "x-symlink") == -1)
261 } else if (file_printf(ms,
262 "unreadable symlink `%s' (%s)", fn,
263 strerror(errno)) == -1)
267 buf[nch] = '\0'; /* readlink(2) does not do this */
269 /* If broken symlink, say so and quit early. */
271 if (stat(buf, &tstatbuf) < 0)
272 return bad_link(ms, errno, buf);
275 char buf2[BUFSIZ+BUFSIZ+4];
277 if ((tmp = strrchr(fn, '/')) == NULL) {
278 tmp = buf; /* in current directory anyway */
280 if (tmp - fn + 1 > BUFSIZ) {
281 if (ms->flags & MAGIC_ERROR) {
283 "path too long: `%s'", buf);
287 if (handle_mime(ms, mime,
288 "x-path-too-long") == -1)
290 } else if (file_printf(ms,
291 "path too long: `%s'", fn) == -1)
296 (void)strlcpy(buf2, fn, sizeof buf2);
297 buf2[tmp - fn + 1] = '\0';
298 /* plus (rel) link */
299 (void)strlcat(buf2, buf, sizeof buf2);
302 if (stat(tmp, &tstatbuf) < 0)
303 return bad_link(ms, errno, buf);
306 /* Otherwise, handle it. */
307 if ((ms->flags & MAGIC_SYMLINK) != 0) {
309 ms->flags &= MAGIC_SYMLINK;
310 p = magic_file(ms, buf);
311 ms->flags |= MAGIC_SYMLINK;
312 return p != NULL ? 1 : -1;
313 } else { /* just print what it points to */
315 if (handle_mime(ms, mime, "x-symlink") == -1)
317 } else if (file_printf(ms, "symbolic link to `%s'",
327 if (handle_mime(ms, mime, "x-socket") == -1)
329 } else if (file_printf(ms, "socket") == -1)
337 file_error(ms, 0, "invalid mode 0%o", sb->st_mode);
343 * regular file, check next possibility
345 * If stat() tells us the file has zero length, report here that
346 * the file is empty, so we can skip all the work of opening and
348 * But if the -s option has been given, we skip this optimization,
349 * since on some systems, stat() reports zero size for raw disk
350 * partitions. (If the block special device really has zero length,
351 * the fact that it is empty will be detected and reported correctly
352 * when we read the file.)
354 if ((ms->flags & MAGIC_DEVICES) == 0 && sb->st_size == 0) {
356 if (handle_mime(ms, mime, "x-empty") == -1)
358 } else if (file_printf(ms, "empty") == -1)