2 * Copyright (c) Christos Zoulas 2003.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice immediately at the beginning of the file, without modification,
10 * this list of conditions, and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
19 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 FILE_RCSID("@(#)$File: magic.c,v 1.84 2014/05/14 23:15:42 christos Exp $")
48 #include <limits.h> /* for PIPE_BUF */
51 #if defined(HAVE_UTIMES)
52 # include <sys/time.h>
53 #elif defined(HAVE_UTIME)
54 # if defined(HAVE_SYS_UTIME_H)
55 # include <sys/utime.h>
56 # elif defined(HAVE_UTIME_H)
62 #include <unistd.h> /* for read() */
66 /* Get the PIPE_BUF from pathconf */
68 #define PIPE_BUF pathconf(".", _PC_PIPE_BUF)
74 private void close_and_restore(const struct magic_set *, const char *, int,
76 private int unreadable_info(struct magic_set *, mode_t, const char *);
77 private const char* get_default_magic(void);
79 private const char *file_or_fd(struct magic_set *, const char *, int);
83 #define STDIN_FILENO 0
87 get_default_magic(void)
89 static const char hmagic[] = "/.magic/magic.mgc";
90 static char *default_magic;
91 char *home, *hmagicpath;
100 if ((home = getenv("HOME")) == NULL)
103 if (asprintf(&hmagicpath, "%s/.magic.mgc", home) < 0)
105 if (stat(hmagicpath, &st) == -1) {
107 if (asprintf(&hmagicpath, "%s/.magic", home) < 0)
109 if (stat(hmagicpath, &st) == -1)
111 if (S_ISDIR(st.st_mode)) {
113 if (asprintf(&hmagicpath, "%s/%s", home, hmagic) < 0)
115 if (access(hmagicpath, R_OK) == -1)
120 if (asprintf(&default_magic, "%s:%s", hmagicpath, MAGIC) < 0)
123 return default_magic;
125 default_magic = NULL;
130 char *tmppath = NULL;
133 #define APPENDPATH() \
135 if (tmppath && access(tmppath, R_OK) != -1) { \
136 if (hmagicpath == NULL) \
137 hmagicpath = tmppath; \
139 if (asprintf(&hmagicp, "%s%c%s", hmagicpath, \
140 PATHSEP, tmppath) >= 0) { \
142 hmagicpath = hmagicp; \
148 } while (/*CONSTCOND*/0)
152 default_magic = NULL;
155 /* First, try to get user-specific magic file */
156 if ((home = getenv("LOCALAPPDATA")) == NULL) {
157 if ((home = getenv("USERPROFILE")) != NULL)
158 if (asprintf(&tmppath,
159 "%s/Local Settings/Application Data%s", home,
163 if (asprintf(&tmppath, "%s%s", home, hmagic) < 0)
169 /* Second, try to get a magic file from Common Files */
170 if ((home = getenv("COMMONPROGRAMFILES")) != NULL) {
171 if (asprintf(&tmppath, "%s%s", home, hmagic) >= 0)
175 /* Third, try to get magic file relative to dll location */
176 LPTSTR dllpath = malloc(sizeof(*dllpath) * (MAX_PATH + 1));
177 dllpath[MAX_PATH] = 0; /* just in case long path gets truncated and not null terminated */
178 if (GetModuleFileNameA(NULL, dllpath, MAX_PATH)){
179 PathRemoveFileSpecA(dllpath);
180 if (strlen(dllpath) > 3 &&
181 stricmp(&dllpath[strlen(dllpath) - 3], "bin") == 0) {
182 if (asprintf(&tmppath,
183 "%s/../share/misc/magic.mgc", dllpath) >= 0)
186 if (asprintf(&tmppath,
187 "%s/share/misc/magic.mgc", dllpath) >= 0)
189 else if (asprintf(&tmppath,
190 "%s/magic.mgc", dllpath) >= 0)
195 /* Don't put MAGIC constant - it likely points to a file within MSys
197 default_magic = hmagicpath;
198 return default_magic;
203 magic_getpath(const char *magicfile, int action)
205 if (magicfile != NULL)
208 magicfile = getenv("MAGIC");
209 if (magicfile != NULL)
212 return action == FILE_LOAD ? get_default_magic() : MAGIC;
215 public struct magic_set *
216 magic_open(int flags)
218 return file_ms_alloc(flags);
222 unreadable_info(struct magic_set *ms, mode_t md, const char *file)
225 /* We cannot open it, but we were able to stat it. */
226 if (access(file, W_OK) == 0)
227 if (file_printf(ms, "writable, ") == -1)
229 if (access(file, X_OK) == 0)
230 if (file_printf(ms, "executable, ") == -1)
234 if (file_printf(ms, "regular file, ") == -1)
236 if (file_printf(ms, "no read permission") == -1)
242 magic_close(struct magic_set *ms)
253 magic_load(struct magic_set *ms, const char *magicfile)
257 return file_apprentice(ms, magicfile, FILE_LOAD);
261 magic_compile(struct magic_set *ms, const char *magicfile)
265 return file_apprentice(ms, magicfile, FILE_COMPILE);
269 magic_check(struct magic_set *ms, const char *magicfile)
273 return file_apprentice(ms, magicfile, FILE_CHECK);
277 magic_list(struct magic_set *ms, const char *magicfile)
281 return file_apprentice(ms, magicfile, FILE_LIST);
285 close_and_restore(const struct magic_set *ms, const char *name, int fd,
286 const struct stat *sb)
288 if (fd == STDIN_FILENO || name == NULL)
292 if ((ms->flags & MAGIC_PRESERVE_ATIME) != 0) {
294 * Try to restore access, modification times if read it.
295 * This is really *bad* because it will modify the status
296 * time of the file... And of course this will affect
300 struct timeval utsbuf[2];
301 (void)memset(utsbuf, 0, sizeof(utsbuf));
302 utsbuf[0].tv_sec = sb->st_atime;
303 utsbuf[1].tv_sec = sb->st_mtime;
305 (void) utimes(name, utsbuf); /* don't care if loses */
306 #elif defined(HAVE_UTIME_H) || defined(HAVE_SYS_UTIME_H)
307 struct utimbuf utbuf;
309 (void)memset(&utbuf, 0, sizeof(utbuf));
310 utbuf.actime = sb->st_atime;
311 utbuf.modtime = sb->st_mtime;
312 (void) utime(name, &utbuf); /* don't care if loses */
320 * find type of descriptor
323 magic_descriptor(struct magic_set *ms, int fd)
327 return file_or_fd(ms, NULL, fd);
331 * find type of named file
334 magic_file(struct magic_set *ms, const char *inname)
338 return file_or_fd(ms, inname, STDIN_FILENO);
342 file_or_fd(struct magic_set *ms, const char *inname, int fd)
347 ssize_t nbytes = 0; /* number of bytes read from a datafile */
349 off_t pos = (off_t)-1;
351 if (file_reset(ms) == -1)
355 * one extra for terminating '\0', and
356 * some overlapping space for matches near EOF
358 #define SLOP (1 + sizeof(union VALUETYPE))
359 if ((buf = CAST(unsigned char *, malloc(HOWMANY + SLOP))) == NULL)
362 switch (file_fsmagic(ms, inname, &sb)) {
365 case 0: /* nothing found */
367 default: /* matched it and printed type */
373 /* Place stdin in binary mode, so EOF (Ctrl+Z) doesn't stop early. */
374 if (fd == STDIN_FILENO)
375 _setmode(STDIN_FILENO, O_BINARY);
378 if (inname == NULL) {
379 if (fstat(fd, &sb) == 0 && S_ISFIFO(sb.st_mode))
382 pos = lseek(fd, (off_t)0, SEEK_CUR);
384 int flags = O_RDONLY|O_BINARY;
385 int okstat = stat(inname, &sb) == 0;
387 if (okstat && S_ISFIFO(sb.st_mode)) {
395 if ((fd = open(inname, flags)) < 0) {
398 * Can't stat, can't open. It may have been opened in
399 * fsmagic, so if the user doesn't have read permission,
400 * allow it to say so; otherwise an error was probably
401 * displayed in fsmagic.
403 if (!okstat && errno == EACCES) {
404 sb.st_mode = S_IFBLK;
409 unreadable_info(ms, sb.st_mode, inname) == -1)
415 if ((flags = fcntl(fd, F_GETFL)) != -1) {
416 flags &= ~O_NONBLOCK;
417 (void)fcntl(fd, F_SETFL, flags);
423 * try looking at the first HOWMANY bytes
428 while ((r = sread(fd, (void *)&buf[nbytes],
429 (size_t)(HOWMANY - nbytes), 1)) > 0) {
431 if (r < PIPE_BUF) break;
435 /* We can not read it, but we were able to stat it. */
436 if (unreadable_info(ms, sb.st_mode, inname) == -1)
443 /* Windows refuses to read from a big console buffer. */
445 #if defined(WIN32) && HOWMANY > 8 * 1024
446 _isatty(fd) ? 8 * 1024 :
449 if ((nbytes = read(fd, (char *)buf, howmany)) == -1) {
450 if (inname == NULL && fd != STDIN_FILENO)
451 file_error(ms, errno, "cannot read fd %d", fd);
453 file_error(ms, errno, "cannot read `%s'",
454 inname == NULL ? "/dev/stdin" : inname);
459 (void)memset(buf + nbytes, 0, SLOP); /* NUL terminate */
460 if (file_buffer(ms, fd, inname, buf, (size_t)nbytes) == -1)
465 if (pos != (off_t)-1)
466 (void)lseek(fd, pos, SEEK_SET);
467 close_and_restore(ms, inname, fd, &sb);
469 return rv == 0 ? file_getbuffer(ms) : NULL;
474 magic_buffer(struct magic_set *ms, const void *buf, size_t nb)
478 if (file_reset(ms) == -1)
481 * The main work is done here!
482 * We have the file name and/or the data buffer to be identified.
484 if (file_buffer(ms, -1, NULL, buf, nb) == -1) {
487 return file_getbuffer(ms);
492 magic_error(struct magic_set *ms)
495 return "Magic database is not open";
496 return (ms->event_flags & EVENT_HAD_ERR) ? ms->o.buf : NULL;
500 magic_errno(struct magic_set *ms)
504 return (ms->event_flags & EVENT_HAD_ERR) ? ms->error : 0;
508 magic_setflags(struct magic_set *ms, int flags)
512 #if !defined(HAVE_UTIME) && !defined(HAVE_UTIMES)
513 if (flags & MAGIC_PRESERVE_ATIME)
523 return MAGIC_VERSION;