1/*
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.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
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.
15 *
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
26 * SUCH DAMAGE.
27 */
28/*
29 * fsmagic - magic based on filesystem info - directory, special files, etc.
30 */
31
32#include "file.h"
33
34#ifndef lint
35FILE_RCSID("@(#)$File: fsmagic.c,v 1.73 2014/05/14 23:15:42 christos Exp $")
36#endif /* lint */
37
38#include "magic.h"
39#include <string.h>
40#ifdef HAVE_UNISTD_H
41#include <unistd.h>
42#endif
43#include <stdlib.h>
44/* Since major is a function on SVR4, we cannot use `ifndef major'. */
45#ifdef MAJOR_IN_MKDEV
46# include <sys/mkdev.h>
47# define HAVE_MAJOR
48#endif
49#ifdef MAJOR_IN_SYSMACROS
50# include <sys/sysmacros.h>
51# define HAVE_MAJOR
52#endif
53#ifdef major /* Might be defined in sys/types.h. */
54# define HAVE_MAJOR
55#endif
56#ifdef WIN32
57# define WIN32_LEAN_AND_MEAN
58# include <windows.h>
59#endif
60
61#ifndef HAVE_MAJOR
62# define major(dev) (((dev) >> 8) & 0xff)
63# define minor(dev) ((dev) & 0xff)
64#endif
65#undef HAVE_MAJOR
66#ifdef S_IFLNK
67private int
68bad_link(struct magic_set *ms, int err, char *buf)
69{
70 int mime = ms->flags & MAGIC_MIME;
71 if ((mime & MAGIC_MIME_TYPE) &&
72 file_printf(ms, "inode/symlink")
73 == -1)
74 return -1;
75 else if (!mime) {
76 if (ms->flags & MAGIC_ERROR) {
77 file_error(ms, err,
78 "broken symbolic link to `%s'", buf);
79 return -1;
80 }
81 if (file_printf(ms, "broken symbolic link to `%s'", buf) == -1)
82 return -1;
83 }
84 return 1;
85}
86#endif
87private int
88handle_mime(struct magic_set *ms, int mime, const char *str)
89{
90 if ((mime & MAGIC_MIME_TYPE)) {
91 if (file_printf(ms, "inode/%s", str) == -1)
92 return -1;
93 if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms,
94 "; charset=") == -1)
95 return -1;
96 }
97 if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms, "binary") == -1)
98 return -1;
99 return 0;
100}
101
102protected int
103file_fsmagic(struct magic_set *ms, const char *fn, struct stat *sb)
104{
105 int ret, did = 0;
106 int mime = ms->flags & MAGIC_MIME;
107#ifdef S_IFLNK
108 char buf[BUFSIZ+4];
109 ssize_t nch;
110 struct stat tstatbuf;
111#endif
112
113 if (ms->flags & MAGIC_APPLE)
114 return 0;
115 if (fn == NULL)
116 return 0;
117
118#define COMMA (did++ ? ", " : "")
119 /*
120 * Fstat is cheaper but fails for files you don't have read perms on.
121 * On 4.2BSD and similar systems, use lstat() to identify symlinks.
122 */
123#ifdef S_IFLNK
124 if ((ms->flags & MAGIC_SYMLINK) == 0)
125 ret = lstat(fn, sb);
126 else
127#endif
128 ret = stat(fn, sb); /* don't merge into if; see "ret =" above */
129
130#ifdef WIN32
131 {
132 HANDLE hFile = CreateFile(fn, 0, FILE_SHARE_DELETE |
133 FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0,
134 NULL);
135 if (hFile != INVALID_HANDLE_VALUE) {
136 /*
137 * Stat failed, but we can still open it - assume it's
138 * a block device, if nothing else.
139 */
140 if (ret) {
141 sb->st_mode = S_IFBLK;
142 ret = 0;
143 }
144 switch (GetFileType(hFile)) {
145 case FILE_TYPE_CHAR:
146 sb->st_mode |= S_IFCHR;
147 sb->st_mode &= ~S_IFREG;
148 break;
149 case FILE_TYPE_PIPE:
150 sb->st_mode |= S_IFIFO;
151 sb->st_mode &= ~S_IFREG;
152 break;
153 }
154 CloseHandle(hFile);
155 }
156 }
157#endif
158
159 if (ret) {
160 if (ms->flags & MAGIC_ERROR) {
161 file_error(ms, errno, "cannot stat `%s'", fn);
162 return -1;
163 }
164 if (file_printf(ms, "cannot open `%s' (%s)",
165 fn, strerror(errno)) == -1)
166 return -1;
167 return 0;
168 }
169
170 ret = 1;
171 if (!mime) {
172#ifdef S_ISUID
173 if (sb->st_mode & S_ISUID)
174 if (file_printf(ms, "%ssetuid", COMMA) == -1)
175 return -1;
176#endif
177#ifdef S_ISGID
178 if (sb->st_mode & S_ISGID)
179 if (file_printf(ms, "%ssetgid", COMMA) == -1)
180 return -1;
181#endif
182#ifdef S_ISVTX
183 if (sb->st_mode & S_ISVTX)
184 if (file_printf(ms, "%ssticky", COMMA) == -1)
185 return -1;
186#endif
187 }
188
189 switch (sb->st_mode & S_IFMT) {
190 case S_IFDIR:
191 if (mime) {
192 if (handle_mime(ms, mime, "directory") == -1)
193 return -1;
194 } else if (file_printf(ms, "%sdirectory", COMMA) == -1)
195 return -1;
196 break;
197#ifdef S_IFCHR
198 case S_IFCHR:
199 /*
200 * If -s has been specified, treat character special files
201 * like ordinary files. Otherwise, just report that they
202 * are block special files and go on to the next file.
203 */
204 if ((ms->flags & MAGIC_DEVICES) != 0) {
205 ret = 0;
206 break;
207 }
208 if (mime) {
209 if (handle_mime(ms, mime, "chardevice") == -1)
210 return -1;
211 } else {
212#ifdef HAVE_STRUCT_STAT_ST_RDEV
213# ifdef dv_unit
214 if (file_printf(ms, "%scharacter special (%d/%d/%d)",
215 COMMA, major(sb->st_rdev), dv_unit(sb->st_rdev),
216 dv_subunit(sb->st_rdev)) == -1)
217 return -1;
218# else
219 if (file_printf(ms, "%scharacter special (%ld/%ld)",
220 COMMA, (long)major(sb->st_rdev),
221 (long)minor(sb->st_rdev)) == -1)
222 return -1;
223# endif
224#else
225 if (file_printf(ms, "%scharacter special", COMMA) == -1)
226 return -1;
227#endif
228 }
229 break;
230#endif
231#ifdef S_IFBLK
232 case S_IFBLK:
233 /*
234 * If -s has been specified, treat block special files
235 * like ordinary files. Otherwise, just report that they
236 * are block special files and go on to the next file.
237 */
238 if ((ms->flags & MAGIC_DEVICES) != 0) {
239 ret = 0;
240 break;
241 }
242 if (mime) {
243 if (handle_mime(ms, mime, "blockdevice") == -1)
244 return -1;
245 } else {
246#ifdef HAVE_STRUCT_STAT_ST_RDEV
247# ifdef dv_unit
248 if (file_printf(ms, "%sblock special (%d/%d/%d)",
249 COMMA, major(sb->st_rdev), dv_unit(sb->st_rdev),
250 dv_subunit(sb->st_rdev)) == -1)
251 return -1;
252# else
253 if (file_printf(ms, "%sblock special (%ld/%ld)",
254 COMMA, (long)major(sb->st_rdev),
255 (long)minor(sb->st_rdev)) == -1)
256 return -1;
257# endif
258#else
259 if (file_printf(ms, "%sblock special", COMMA) == -1)
260 return -1;
261#endif
262 }
263 break;
264#endif
265 /* TODO add code to handle V7 MUX and Blit MUX files */
266#ifdef S_IFIFO
267 case S_IFIFO:
268 if((ms->flags & MAGIC_DEVICES) != 0)
269 break;
270 if (mime) {
271 if (handle_mime(ms, mime, "fifo") == -1)
272 return -1;
273 } else if (file_printf(ms, "%sfifo (named pipe)", COMMA) == -1)
274 return -1;
275 break;
276#endif
277#ifdef S_IFDOOR
278 case S_IFDOOR:
279 if (mime) {
280 if (handle_mime(ms, mime, "door") == -1)
281 return -1;
282 } else if (file_printf(ms, "%sdoor", COMMA) == -1)
283 return -1;
284 break;
285#endif
286#ifdef S_IFLNK
287 case S_IFLNK:
288 if ((nch = readlink(fn, buf, BUFSIZ-1)) <= 0) {
289 if (ms->flags & MAGIC_ERROR) {
290 file_error(ms, errno, "unreadable symlink `%s'",
291 fn);
292 return -1;
293 }
294 if (mime) {
295 if (handle_mime(ms, mime, "symlink") == -1)
296 return -1;
297 } else if (file_printf(ms,
298 "%sunreadable symlink `%s' (%s)", COMMA, fn,
299 strerror(errno)) == -1)
300 return -1;
301 break;
302 }
303 buf[nch] = '\0'; /* readlink(2) does not do this */
304
305 /* If broken symlink, say so and quit early. */
306 if (*buf == '/') {
307 if (stat(buf, &tstatbuf) < 0)
308 return bad_link(ms, errno, buf);
309 } else {
310 char *tmp;
311 char buf2[BUFSIZ+BUFSIZ+4];
312
313 if ((tmp = strrchr(fn, '/')) == NULL) {
314 tmp = buf; /* in current directory anyway */
315 } else {
316 if (tmp - fn + 1 > BUFSIZ) {
317 if (ms->flags & MAGIC_ERROR) {
318 file_error(ms, 0,
319 "path too long: `%s'", buf);
320 return -1;
321 }
322 if (mime) {
323 if (handle_mime(ms, mime,
324 "x-path-too-long") == -1)
325 return -1;
326 } else if (file_printf(ms,
327 "%spath too long: `%s'", COMMA,
328 fn) == -1)
329 return -1;
330 break;
331 }
332 /* take dir part */
333 (void)strlcpy(buf2, fn, sizeof buf2);
334 buf2[tmp - fn + 1] = '\0';
335 /* plus (rel) link */
336 (void)strlcat(buf2, buf, sizeof buf2);
337 tmp = buf2;
338 }
339 if (stat(tmp, &tstatbuf) < 0)
340 return bad_link(ms, errno, buf);
341 }
342
343 /* Otherwise, handle it. */
344 if ((ms->flags & MAGIC_SYMLINK) != 0) {
345 const char *p;
346 ms->flags &= MAGIC_SYMLINK;
347 p = magic_file(ms, buf);
348 ms->flags |= MAGIC_SYMLINK;
349 if (p == NULL)
350 return -1;
351 } else { /* just print what it points to */
352 if (mime) {
353 if (handle_mime(ms, mime, "symlink") == -1)
354 return -1;
355 } else if (file_printf(ms, "%ssymbolic link to `%s'",
356 COMMA, buf) == -1)
357 return -1;
358 }
359 break;
360#endif
361#ifdef S_IFSOCK
362#ifndef __COHERENT__
363 case S_IFSOCK:
364 if (mime) {
365 if (handle_mime(ms, mime, "socket") == -1)
366 return -1;
367 } else if (file_printf(ms, "%ssocket", COMMA) == -1)
368 return -1;
369 break;
370#endif
371#endif
372 case S_IFREG:
373 /*
374 * regular file, check next possibility
375 *
376 * If stat() tells us the file has zero length, report here that
377 * the file is empty, so we can skip all the work of opening and
378 * reading the file.
379 * But if the -s option has been given, we skip this
380 * optimization, since on some systems, stat() reports zero
381 * size for raw disk partitions. (If the block special device
382 * really has zero length, the fact that it is empty will be
383 * detected and reported correctly when we read the file.)
384 */
385 if ((ms->flags & MAGIC_DEVICES) == 0 && sb->st_size == 0) {
386 if (mime) {
387 if (handle_mime(ms, mime, "x-empty") == -1)
388 return -1;
389 } else if (file_printf(ms, "%sempty", COMMA) == -1)
390 return -1;
391 break;
392 }
393 ret = 0;
394 break;
395
396 default:
397 file_error(ms, 0, "invalid mode 0%o", sb->st_mode);
398 return -1;
399 /*NOTREACHED*/
400 }
401
402 if (!mime && did && ret == 0) {
403 if (file_printf(ms, " ") == -1)
404 return -1;
405 }
406 return ret;
407}