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
35 #include <sys/types.h>
36 #include <sys/param.h> /* for MAXPATHLEN */
41 #include <limits.h> /* for PIPE_BUF */
43 #if defined(HAVE_UTIMES)
44 # include <sys/time.h>
45 #elif defined(HAVE_UTIME)
46 # if defined(HAVE_SYS_UTIME_H)
47 # include <sys/utime.h>
48 # elif defined(HAVE_UTIME_H)
54 #include <unistd.h> /* for read() */
61 #include <netinet/in.h> /* for byte swapping */
63 #include "patchlevel.h"
66 FILE_RCSID("@(#)$Id: magic.c,v 1.35 2006/10/31 19:37:17 christos Exp $")
70 private char *apptypeName = NULL;
71 protected int file_os2_apptype(struct magic_set *ms, const char *fn,
72 const void *buf, size_t nb);
75 private void free_mlist(struct mlist *);
76 private void close_and_restore(const struct magic_set *, const char *, int,
78 private int info_from_stat(struct magic_set *, mode_t);
81 #define STDIN_FILENO 0
84 public struct magic_set *
89 if ((ms = malloc(sizeof(struct magic_set))) == NULL)
92 if (magic_setflags(ms, flags) == -1) {
97 ms->o.ptr = ms->o.buf = malloc(ms->o.size = 1024);
98 if (ms->o.buf == NULL)
101 ms->o.pbuf = malloc(ms->o.psize = 1024);
102 if (ms->o.pbuf == NULL)
105 ms->c.off = malloc((ms->c.len = 10) * sizeof(*ms->c.off));
106 if (ms->c.off == NULL)
124 free_mlist(struct mlist *mlist)
131 for (ml = mlist->next; ml != mlist;) {
132 struct mlist *next = ml->next;
133 struct magic *mg = ml->magic;
134 file_delmagic(mg, ml->mapped, ml->nmagic);
142 info_from_stat(struct magic_set *ms, mode_t md)
144 /* We cannot open it, but we were able to stat it. */
146 if (file_printf(ms, "writable, ") == -1)
149 if (file_printf(ms, "executable, ") == -1)
152 if (file_printf(ms, "regular file, ") == -1)
154 if (file_printf(ms, "no read permission") == -1)
160 magic_close(struct magic_set *ms)
162 free_mlist(ms->mlist);
173 magic_load(struct magic_set *ms, const char *magicfile)
175 struct mlist *ml = file_apprentice(ms, magicfile, FILE_LOAD);
177 free_mlist(ms->mlist);
185 magic_compile(struct magic_set *ms, const char *magicfile)
187 struct mlist *ml = file_apprentice(ms, magicfile, FILE_COMPILE);
193 magic_check(struct magic_set *ms, const char *magicfile)
195 struct mlist *ml = file_apprentice(ms, magicfile, FILE_CHECK);
201 close_and_restore(const struct magic_set *ms, const char *name, int fd,
202 const struct stat *sb)
204 if (fd == STDIN_FILENO)
208 if ((ms->flags & MAGIC_PRESERVE_ATIME) != 0) {
210 * Try to restore access, modification times if read it.
211 * This is really *bad* because it will modify the status
212 * time of the file... And of course this will affect
216 struct timeval utsbuf[2];
217 utsbuf[0].tv_sec = sb->st_atime;
218 utsbuf[1].tv_sec = sb->st_mtime;
220 (void) utimes(name, utsbuf); /* don't care if loses */
221 #elif defined(HAVE_UTIME_H) || defined(HAVE_SYS_UTIME_H)
222 struct utimbuf utbuf;
224 utbuf.actime = sb->st_atime;
225 utbuf.modtime = sb->st_mtime;
226 (void) utime(name, &utbuf); /* don't care if loses */
233 * find type of named file
236 magic_file(struct magic_set *ms, const char *inname)
242 ssize_t nbytes = 0; /* number of bytes read from a datafile */
246 * one extra for terminating '\0', and
247 * some overlapping space for matches near EOF
249 #define SLOP (1 + sizeof(union VALUETYPE))
250 if ((buf = malloc(HOWMANY + SLOP)) == NULL)
253 if (file_reset(ms) == -1)
256 switch (file_fsmagic(ms, inname, &sb)) {
259 case 0: /* nothing found */
261 default: /* matched it and printed type */
266 if (inname == NULL) {
268 if (fstat(fd, &sb) == 0 && S_ISFIFO(sb.st_mode))
271 int flags = O_RDONLY|O_BINARY;
273 if (stat(inname, &sb) == 0 && S_ISFIFO(sb.st_mode)) {
279 if ((fd = open(inname, flags)) < 0) {
281 char *tmp = alloca(strlen(inname) + 5);
282 (void)strcat(strcpy(tmp, inname), ".exe");
283 if ((fd = open(tmp, flags)) < 0) {
285 if (info_from_stat(ms, sb.st_mode) == -1)
294 if ((flags = fcntl(fd, F_GETFL)) != -1) {
295 flags &= ~O_NONBLOCK;
296 (void)fcntl(fd, F_SETFL, flags);
302 * try looking at the first HOWMANY bytes
307 while ((r = sread(fd, (void *)&buf[nbytes],
308 (size_t)(HOWMANY - nbytes))) > 0) {
310 if (r < PIPE_BUF) break;
314 /* We can not read it, but we were able to stat it. */
315 if (info_from_stat(ms, sb.st_mode) == -1)
322 if ((nbytes = read(fd, (char *)buf, HOWMANY)) == -1) {
323 file_error(ms, errno, "cannot read `%s'", inname);
329 if (file_printf(ms, (ms->flags & MAGIC_MIME) ?
330 "application/x-empty" : "empty") == -1)
332 } else if (nbytes == 1) {
333 if (file_printf(ms, "very short file (no magic)") == -1)
336 (void)memset(buf + nbytes, 0, SLOP); /* NUL terminate */
338 switch (file_os2_apptype(ms, inname, buf, nbytes)) {
348 if (file_buffer(ms, fd, buf, (size_t)nbytes) == -1)
353 * We matched something in the file, so this *might*
354 * be an ELF file, and the file is at least 5 bytes
355 * long, so if it's an ELF file it has at least one
356 * byte past the ELF magic number - try extracting
357 * information from the ELF headers that cannot easily
358 * be extracted with rules in the magic file.
360 file_tryelf(ms, fd, buf, (size_t)nbytes);
367 close_and_restore(ms, inname, fd, &sb);
368 return rv == 0 ? file_getbuffer(ms) : NULL;
373 magic_buffer(struct magic_set *ms, const void *buf, size_t nb)
375 if (file_reset(ms) == -1)
378 * The main work is done here!
379 * We have the file name and/or the data buffer to be identified.
381 if (file_buffer(ms, -1, buf, nb) == -1) {
384 return file_getbuffer(ms);
389 magic_error(struct magic_set *ms)
391 return ms->haderr ? ms->o.buf : NULL;
395 magic_errno(struct magic_set *ms)
397 return ms->haderr ? ms->error : 0;
401 magic_setflags(struct magic_set *ms, int flags)
403 #if !defined(HAVE_UTIME) && !defined(HAVE_UTIMES)
404 if (flags & MAGIC_PRESERVE_ATIME)