516 lines
12 KiB
C
516 lines
12 KiB
C
/*
|
|
* Copyright (c) Christos Zoulas 2003.
|
|
* All Rights Reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice immediately at the beginning of the file, without modification,
|
|
* this list of conditions, and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
|
|
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#ifdef WIN32
|
|
#include <windows.h>
|
|
#include <shlwapi.h>
|
|
#endif
|
|
|
|
#include "file.h"
|
|
|
|
#ifndef lint
|
|
FILE_RCSID("@(#)$File: magic.c,v 1.74 2011/05/26 01:27:59 christos Exp $")
|
|
#endif /* lint */
|
|
|
|
#include "magic.h"
|
|
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <string.h>
|
|
#ifdef QUICK
|
|
#include <sys/mman.h>
|
|
#endif
|
|
#ifdef HAVE_LIMITS_H
|
|
#include <limits.h> /* for PIPE_BUF */
|
|
#endif
|
|
|
|
#if defined(HAVE_UTIMES)
|
|
# include <sys/time.h>
|
|
#elif defined(HAVE_UTIME)
|
|
# if defined(HAVE_SYS_UTIME_H)
|
|
# include <sys/utime.h>
|
|
# elif defined(HAVE_UTIME_H)
|
|
# include <utime.h>
|
|
# endif
|
|
#endif
|
|
|
|
#ifdef HAVE_UNISTD_H
|
|
#include <unistd.h> /* for read() */
|
|
#endif
|
|
|
|
#ifndef PIPE_BUF
|
|
/* Get the PIPE_BUF from pathconf */
|
|
#ifdef _PC_PIPE_BUF
|
|
#define PIPE_BUF pathconf(".", _PC_PIPE_BUF)
|
|
#else
|
|
#define PIPE_BUF 512
|
|
#endif
|
|
#endif
|
|
|
|
private void free_mlist(struct mlist *);
|
|
#ifndef COMPILE_ONLY
|
|
private void close_and_restore(const struct magic_set *, const char *, int,
|
|
const struct stat *);
|
|
private int unreadable_info(struct magic_set *, mode_t, const char *);
|
|
private const char* get_default_magic(void);
|
|
private const char *file_or_fd(struct magic_set *, const char *, int);
|
|
#endif
|
|
|
|
#ifndef STDIN_FILENO
|
|
#define STDIN_FILENO 0
|
|
#endif
|
|
|
|
private const char *
|
|
get_default_magic(void)
|
|
{
|
|
static const char hmagic[] = "/.magic/magic.mgc";
|
|
static char *default_magic;
|
|
char *home, *hmagicpath;
|
|
|
|
#ifndef WIN32
|
|
struct stat st;
|
|
|
|
if (default_magic) {
|
|
free(default_magic);
|
|
default_magic = NULL;
|
|
}
|
|
if ((home = getenv("HOME")) == NULL)
|
|
return MAGIC;
|
|
|
|
if (asprintf(&hmagicpath, "%s/.magic", home) < 0)
|
|
return MAGIC;
|
|
if (stat(hmagicpath, &st) == -1)
|
|
goto out;
|
|
if (S_ISDIR(st.st_mode)) {
|
|
free(hmagicpath);
|
|
if (asprintf(&hmagicpath, "%s/%s", home, hmagic) < 0)
|
|
return MAGIC;
|
|
if (access(hmagicpath, R_OK) == -1)
|
|
goto out;
|
|
}
|
|
|
|
if (asprintf(&default_magic, "%s:%s", hmagicpath, MAGIC) < 0)
|
|
goto out;
|
|
free(hmagicpath);
|
|
return default_magic;
|
|
out:
|
|
default_magic = NULL;
|
|
free(hmagicpath);
|
|
return MAGIC;
|
|
#else
|
|
char *hmagicp = hmagicpath;
|
|
char *tmppath = NULL;
|
|
|
|
#define APPENDPATH() \
|
|
do { \
|
|
if (tmppath && access(tmppath, R_OK) != -1) { \
|
|
if (hmagicpath == NULL) \
|
|
hmagicpath = tmppath; \
|
|
else { \
|
|
if (asprintf(&hmagicp, "%s%c%s", hmagicpath, \
|
|
PATHSEP, tmppath) >= 0) { \
|
|
free(hmagicpath); \
|
|
hmagicpath = hmagicp; \
|
|
} \
|
|
free(tmppath); \
|
|
} \
|
|
tmppath = NULL; \
|
|
} \
|
|
} while (/*CONSTCOND*/0)
|
|
|
|
if (default_magic) {
|
|
free(default_magic);
|
|
default_magic = NULL;
|
|
}
|
|
|
|
/* First, try to get user-specific magic file */
|
|
if ((home = getenv("LOCALAPPDATA")) == NULL) {
|
|
if ((home = getenv("USERPROFILE")) != NULL)
|
|
if (asprintf(&tmppath,
|
|
"%s/Local Settings/Application Data%s", home,
|
|
hmagic) < 0)
|
|
tmppath = NULL;
|
|
} else {
|
|
if (asprintf(&tmppath, "%s%s", home, hmagic) < 0)
|
|
tmppath = NULL;
|
|
}
|
|
|
|
APPENDPATH();
|
|
|
|
/* Second, try to get a magic file from Common Files */
|
|
if ((home = getenv("COMMONPROGRAMFILES")) != NULL) {
|
|
if (asprintf(&tmppath, "%s%s", home, hmagic) >= 0)
|
|
APPENDPATH();
|
|
}
|
|
|
|
/* Third, try to get magic file relative to dll location */
|
|
LPTSTR dllpath = malloc(sizeof(*dllpath) * (MAX_PATH + 1));
|
|
dllpath[MAX_PATH] = 0; /* just in case long path gets truncated and not null terminated */
|
|
if (GetModuleFileNameA(NULL, dllpath, MAX_PATH)){
|
|
PathRemoveFileSpecA(dllpath);
|
|
if (strlen(dllpath) > 3 &&
|
|
stricmp(&dllpath[strlen(dllpath) - 3], "bin") == 0) {
|
|
if (asprintf(&tmppath,
|
|
"%s/../share/misc/magic.mgc", dllpath) >= 0)
|
|
APPENDPATH();
|
|
} else {
|
|
if (asprintf(&tmppath,
|
|
"%s/share/misc/magic.mgc", dllpath) >= 0)
|
|
APPENDPATH();
|
|
else if (asprintf(&tmppath,
|
|
"%s/magic.mgc", dllpath) >= 0)
|
|
APPENDPATH();
|
|
}
|
|
}
|
|
|
|
/* Don't put MAGIC constant - it likely points to a file within MSys
|
|
tree */
|
|
default_magic = hmagicpath;
|
|
return default_magic;
|
|
#endif
|
|
}
|
|
|
|
public const char *
|
|
magic_getpath(const char *magicfile, int action)
|
|
{
|
|
if (magicfile != NULL)
|
|
return magicfile;
|
|
|
|
magicfile = getenv("MAGIC");
|
|
if (magicfile != NULL)
|
|
return magicfile;
|
|
|
|
return action == FILE_LOAD ? get_default_magic() : MAGIC;
|
|
}
|
|
|
|
public struct magic_set *
|
|
magic_open(int flags)
|
|
{
|
|
struct magic_set *ms;
|
|
size_t len;
|
|
|
|
if ((ms = CAST(struct magic_set *, calloc((size_t)1,
|
|
sizeof(struct magic_set)))) == NULL)
|
|
return NULL;
|
|
|
|
if (magic_setflags(ms, flags) == -1) {
|
|
errno = EINVAL;
|
|
goto free;
|
|
}
|
|
|
|
ms->o.buf = ms->o.pbuf = NULL;
|
|
len = (ms->c.len = 10) * sizeof(*ms->c.li);
|
|
|
|
if ((ms->c.li = CAST(struct level_info *, malloc(len))) == NULL)
|
|
goto free;
|
|
|
|
ms->event_flags = 0;
|
|
ms->error = -1;
|
|
ms->mlist = NULL;
|
|
ms->file = "unknown";
|
|
ms->line = 0;
|
|
return ms;
|
|
free:
|
|
free(ms);
|
|
return NULL;
|
|
}
|
|
|
|
private void
|
|
free_mlist(struct mlist *mlist)
|
|
{
|
|
struct mlist *ml;
|
|
|
|
if (mlist == NULL)
|
|
return;
|
|
|
|
for (ml = mlist->next; ml != mlist;) {
|
|
struct mlist *next = ml->next;
|
|
struct magic *mg = ml->magic;
|
|
file_delmagic(mg, ml->mapped, ml->nmagic);
|
|
free(ml);
|
|
ml = next;
|
|
}
|
|
free(ml);
|
|
}
|
|
|
|
#ifndef COMPILE_ONLY
|
|
private int
|
|
unreadable_info(struct magic_set *ms, mode_t md, const char *file)
|
|
{
|
|
/* We cannot open it, but we were able to stat it. */
|
|
if (access(file, W_OK) == 0)
|
|
if (file_printf(ms, "writable, ") == -1)
|
|
return -1;
|
|
if (access(file, X_OK) == 0)
|
|
if (file_printf(ms, "executable, ") == -1)
|
|
return -1;
|
|
if (S_ISREG(md))
|
|
if (file_printf(ms, "regular file, ") == -1)
|
|
return -1;
|
|
if (file_printf(ms, "no read permission") == -1)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
public void
|
|
magic_close(struct magic_set *ms)
|
|
{
|
|
free_mlist(ms->mlist);
|
|
free(ms->o.pbuf);
|
|
free(ms->o.buf);
|
|
free(ms->c.li);
|
|
free(ms);
|
|
}
|
|
|
|
/*
|
|
* load a magic file
|
|
*/
|
|
public int
|
|
magic_load(struct magic_set *ms, const char *magicfile)
|
|
{
|
|
struct mlist *ml = file_apprentice(ms, magicfile, FILE_LOAD);
|
|
if (ml) {
|
|
free_mlist(ms->mlist);
|
|
ms->mlist = ml;
|
|
return 0;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
public int
|
|
magic_compile(struct magic_set *ms, const char *magicfile)
|
|
{
|
|
struct mlist *ml = file_apprentice(ms, magicfile, FILE_COMPILE);
|
|
free_mlist(ml);
|
|
return ml ? 0 : -1;
|
|
}
|
|
|
|
public int
|
|
magic_check(struct magic_set *ms, const char *magicfile)
|
|
{
|
|
struct mlist *ml = file_apprentice(ms, magicfile, FILE_CHECK);
|
|
free_mlist(ml);
|
|
return ml ? 0 : -1;
|
|
}
|
|
|
|
public int
|
|
magic_list(struct magic_set *ms, const char *magicfile)
|
|
{
|
|
struct mlist *ml = file_apprentice(ms, magicfile, FILE_LIST);
|
|
free_mlist(ml);
|
|
return ml ? 0 : -1;
|
|
}
|
|
|
|
#ifndef COMPILE_ONLY
|
|
private void
|
|
close_and_restore(const struct magic_set *ms, const char *name, int fd,
|
|
const struct stat *sb)
|
|
{
|
|
if (fd == STDIN_FILENO)
|
|
return;
|
|
(void) close(fd);
|
|
|
|
if ((ms->flags & MAGIC_PRESERVE_ATIME) != 0) {
|
|
/*
|
|
* Try to restore access, modification times if read it.
|
|
* This is really *bad* because it will modify the status
|
|
* time of the file... And of course this will affect
|
|
* backup programs
|
|
*/
|
|
#ifdef HAVE_UTIMES
|
|
struct timeval utsbuf[2];
|
|
(void)memset(utsbuf, 0, sizeof(utsbuf));
|
|
utsbuf[0].tv_sec = sb->st_atime;
|
|
utsbuf[1].tv_sec = sb->st_mtime;
|
|
|
|
(void) utimes(name, utsbuf); /* don't care if loses */
|
|
#elif defined(HAVE_UTIME_H) || defined(HAVE_SYS_UTIME_H)
|
|
struct utimbuf utbuf;
|
|
|
|
(void)memset(&utbuf, 0, sizeof(utbuf));
|
|
utbuf.actime = sb->st_atime;
|
|
utbuf.modtime = sb->st_mtime;
|
|
(void) utime(name, &utbuf); /* don't care if loses */
|
|
#endif
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* find type of descriptor
|
|
*/
|
|
public const char *
|
|
magic_descriptor(struct magic_set *ms, int fd)
|
|
{
|
|
return file_or_fd(ms, NULL, fd);
|
|
}
|
|
|
|
/*
|
|
* find type of named file
|
|
*/
|
|
public const char *
|
|
magic_file(struct magic_set *ms, const char *inname)
|
|
{
|
|
return file_or_fd(ms, inname, STDIN_FILENO);
|
|
}
|
|
|
|
private const char *
|
|
file_or_fd(struct magic_set *ms, const char *inname, int fd)
|
|
{
|
|
int rv = -1;
|
|
unsigned char *buf;
|
|
struct stat sb;
|
|
ssize_t nbytes = 0; /* number of bytes read from a datafile */
|
|
int ispipe = 0;
|
|
|
|
/*
|
|
* one extra for terminating '\0', and
|
|
* some overlapping space for matches near EOF
|
|
*/
|
|
#define SLOP (1 + sizeof(union VALUETYPE))
|
|
if ((buf = CAST(unsigned char *, malloc(HOWMANY + SLOP))) == NULL)
|
|
return NULL;
|
|
|
|
if (file_reset(ms) == -1)
|
|
goto done;
|
|
|
|
switch (file_fsmagic(ms, inname, &sb)) {
|
|
case -1: /* error */
|
|
goto done;
|
|
case 0: /* nothing found */
|
|
break;
|
|
default: /* matched it and printed type */
|
|
rv = 0;
|
|
goto done;
|
|
}
|
|
|
|
if (inname == NULL) {
|
|
if (fstat(fd, &sb) == 0 && S_ISFIFO(sb.st_mode))
|
|
ispipe = 1;
|
|
} else {
|
|
int flags = O_RDONLY|O_BINARY;
|
|
|
|
if (stat(inname, &sb) == 0 && S_ISFIFO(sb.st_mode)) {
|
|
#ifdef O_NONBLOCK
|
|
flags |= O_NONBLOCK;
|
|
#endif
|
|
ispipe = 1;
|
|
}
|
|
|
|
errno = 0;
|
|
if ((fd = open(inname, flags)) < 0) {
|
|
if (unreadable_info(ms, sb.st_mode, inname) == -1)
|
|
goto done;
|
|
rv = 0;
|
|
goto done;
|
|
}
|
|
#ifdef O_NONBLOCK
|
|
if ((flags = fcntl(fd, F_GETFL)) != -1) {
|
|
flags &= ~O_NONBLOCK;
|
|
(void)fcntl(fd, F_SETFL, flags);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* try looking at the first HOWMANY bytes
|
|
*/
|
|
if (ispipe) {
|
|
ssize_t r = 0;
|
|
|
|
while ((r = sread(fd, (void *)&buf[nbytes],
|
|
(size_t)(HOWMANY - nbytes), 1)) > 0) {
|
|
nbytes += r;
|
|
if (r < PIPE_BUF) break;
|
|
}
|
|
|
|
if (nbytes == 0) {
|
|
/* We can not read it, but we were able to stat it. */
|
|
if (unreadable_info(ms, sb.st_mode, inname) == -1)
|
|
goto done;
|
|
rv = 0;
|
|
goto done;
|
|
}
|
|
|
|
} else {
|
|
if ((nbytes = read(fd, (char *)buf, HOWMANY)) == -1) {
|
|
file_error(ms, errno, "cannot read `%s'", inname);
|
|
goto done;
|
|
}
|
|
}
|
|
|
|
(void)memset(buf + nbytes, 0, SLOP); /* NUL terminate */
|
|
if (file_buffer(ms, fd, inname, buf, (size_t)nbytes) == -1)
|
|
goto done;
|
|
rv = 0;
|
|
done:
|
|
free(buf);
|
|
close_and_restore(ms, inname, fd, &sb);
|
|
return rv == 0 ? file_getbuffer(ms) : NULL;
|
|
}
|
|
|
|
|
|
public const char *
|
|
magic_buffer(struct magic_set *ms, const void *buf, size_t nb)
|
|
{
|
|
if (file_reset(ms) == -1)
|
|
return NULL;
|
|
/*
|
|
* The main work is done here!
|
|
* We have the file name and/or the data buffer to be identified.
|
|
*/
|
|
if (file_buffer(ms, -1, NULL, buf, nb) == -1) {
|
|
return NULL;
|
|
}
|
|
return file_getbuffer(ms);
|
|
}
|
|
#endif /* COMPILE_ONLY */
|
|
|
|
public const char *
|
|
magic_error(struct magic_set *ms)
|
|
{
|
|
return (ms->event_flags & EVENT_HAD_ERR) ? ms->o.buf : NULL;
|
|
}
|
|
|
|
public int
|
|
magic_errno(struct magic_set *ms)
|
|
{
|
|
return (ms->event_flags & EVENT_HAD_ERR) ? ms->error : 0;
|
|
}
|
|
|
|
public int
|
|
magic_setflags(struct magic_set *ms, int flags)
|
|
{
|
|
#if !defined(HAVE_UTIME) && !defined(HAVE_UTIMES)
|
|
if (flags & MAGIC_PRESERVE_ATIME)
|
|
return -1;
|
|
#endif
|
|
ms->flags = flags;
|
|
return 0;
|
|
}
|