9137be5ffd
*- file is now broken into a library containing and processing the magic and a consumer binary.
404 lines
9.4 KiB
C
404 lines
9.4 KiB
C
/*
|
|
* Copyright (c) Ian F. Darwin 1986-1995.
|
|
* Software written by Ian F. Darwin and others;
|
|
* maintained 1995-present by Christos Zoulas and others.
|
|
*
|
|
* 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.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by Ian F. Darwin and others.
|
|
* 4. The name of the author may not be used to endorse or promote products
|
|
* derived from this software without specific prior written permission.
|
|
*
|
|
* 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.
|
|
*/
|
|
/*
|
|
* compress routines:
|
|
* zmagic() - returns 0 if not recognized, uncompresses and prints
|
|
* information if recognized
|
|
* uncompress(method, old, n, newch) - uncompress old into new,
|
|
* using method, return sizeof new
|
|
*/
|
|
#include "file.h"
|
|
#include "magic.h"
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#ifdef HAVE_UNISTD_H
|
|
#include <unistd.h>
|
|
#endif
|
|
#include <string.h>
|
|
#include <errno.h>
|
|
#include <sys/types.h>
|
|
#ifdef HAVE_SYS_WAIT_H
|
|
#include <sys/wait.h>
|
|
#endif
|
|
#ifdef HAVE_LIBZ
|
|
#include <zlib.h>
|
|
#endif
|
|
|
|
#ifndef lint
|
|
FILE_RCSID("@(#)$Id: compress.c,v 1.37 2004/07/24 21:00:56 christos Exp $")
|
|
#endif
|
|
|
|
|
|
private struct {
|
|
const char *magic;
|
|
size_t maglen;
|
|
const char *const argv[3];
|
|
int silent;
|
|
} compr[] = {
|
|
{ "\037\235", 2, { "gzip", "-cdq", NULL }, 1 }, /* compressed */
|
|
/* Uncompress can get stuck; so use gzip first if we have it
|
|
* Idea from Damien Clark, thanks! */
|
|
{ "\037\235", 2, { "uncompress", "-c", NULL }, 1 }, /* compressed */
|
|
{ "\037\213", 2, { "gzip", "-cdq", NULL }, 1 }, /* gzipped */
|
|
{ "\037\236", 2, { "gzip", "-cdq", NULL }, 1 }, /* frozen */
|
|
{ "\037\240", 2, { "gzip", "-cdq", NULL }, 1 }, /* SCO LZH */
|
|
/* the standard pack utilities do not accept standard input */
|
|
{ "\037\036", 2, { "gzip", "-cdq", NULL }, 0 }, /* packed */
|
|
{ "BZh", 3, { "bzip2", "-cd", NULL }, 1 }, /* bzip2-ed */
|
|
};
|
|
|
|
private int ncompr = sizeof(compr) / sizeof(compr[0]);
|
|
|
|
|
|
private ssize_t swrite(int, const void *, size_t);
|
|
private ssize_t sread(int, void *, size_t);
|
|
private size_t uncompressbuf(struct magic_set *, size_t, const unsigned char *,
|
|
unsigned char **, size_t);
|
|
#ifdef HAVE_LIBZ
|
|
private size_t uncompressgzipped(struct magic_set *, const unsigned char *,
|
|
unsigned char **, size_t);
|
|
#endif
|
|
|
|
protected int
|
|
file_zmagic(struct magic_set *ms, const unsigned char *buf, size_t nbytes)
|
|
{
|
|
unsigned char *newbuf = NULL;
|
|
size_t i, nsz;
|
|
int rv = 0;
|
|
|
|
if ((ms->flags & MAGIC_COMPRESS) == 0)
|
|
return 0;
|
|
|
|
for (i = 0; i < ncompr; i++) {
|
|
if (nbytes < compr[i].maglen)
|
|
continue;
|
|
if (memcmp(buf, compr[i].magic, compr[i].maglen) == 0 &&
|
|
(nsz = uncompressbuf(ms, i, buf, &newbuf, nbytes)) != 0) {
|
|
ms->flags &= ~MAGIC_COMPRESS;
|
|
rv = -1;
|
|
if (file_buffer(ms, newbuf, nsz) == -1)
|
|
goto error;
|
|
if (file_printf(ms, " (") == -1)
|
|
goto error;
|
|
if (file_buffer(ms, buf, nbytes) == -1)
|
|
goto error;
|
|
if (file_printf(ms, ")") == -1)
|
|
goto error;
|
|
rv = 1;
|
|
break;
|
|
}
|
|
}
|
|
error:
|
|
if (newbuf)
|
|
free(newbuf);
|
|
ms->flags |= MAGIC_COMPRESS;
|
|
return rv;
|
|
}
|
|
|
|
/*
|
|
* `safe' write for sockets and pipes.
|
|
*/
|
|
private ssize_t
|
|
swrite(int fd, const void *buf, size_t n)
|
|
{
|
|
int rv;
|
|
size_t rn = n;
|
|
|
|
do
|
|
switch (rv = write(fd, buf, n)) {
|
|
case -1:
|
|
if (errno == EINTR)
|
|
continue;
|
|
return -1;
|
|
default:
|
|
n -= rv;
|
|
buf = ((const char *)buf) + rv;
|
|
break;
|
|
}
|
|
while (n > 0);
|
|
return rn;
|
|
}
|
|
|
|
|
|
/*
|
|
* `safe' read for sockets and pipes.
|
|
*/
|
|
private ssize_t
|
|
sread(int fd, void *buf, size_t n)
|
|
{
|
|
int rv;
|
|
size_t rn = n;
|
|
|
|
do
|
|
switch (rv = read(fd, buf, n)) {
|
|
case -1:
|
|
if (errno == EINTR)
|
|
continue;
|
|
return -1;
|
|
case 0:
|
|
return rn - n;
|
|
default:
|
|
n -= rv;
|
|
buf = ((char *)buf) + rv;
|
|
break;
|
|
}
|
|
while (n > 0);
|
|
return rn;
|
|
}
|
|
|
|
protected int
|
|
file_pipe2file(struct magic_set *ms, int fd, const void *startbuf,
|
|
size_t nbytes)
|
|
{
|
|
char buf[4096];
|
|
int r, tfd;
|
|
|
|
(void)strcpy(buf, "/tmp/file.XXXXXX");
|
|
#ifndef HAVE_MKSTEMP
|
|
{
|
|
char *ptr = mktemp(buf);
|
|
tfd = open(ptr, O_RDWR|O_TRUNC|O_EXCL|O_CREAT, 0600);
|
|
r = errno;
|
|
(void)unlink(ptr);
|
|
errno = r;
|
|
}
|
|
#else
|
|
tfd = mkstemp(buf);
|
|
r = errno;
|
|
(void)unlink(buf);
|
|
errno = r;
|
|
#endif
|
|
if (tfd == -1) {
|
|
file_error(ms, errno,
|
|
"cannot create temporary file for pipe copy");
|
|
return -1;
|
|
}
|
|
|
|
if (swrite(tfd, startbuf, nbytes) != (ssize_t)nbytes)
|
|
r = 1;
|
|
else {
|
|
while ((r = sread(fd, buf, sizeof(buf))) > 0)
|
|
if (swrite(tfd, buf, (size_t)r) != r)
|
|
break;
|
|
}
|
|
|
|
switch (r) {
|
|
case -1:
|
|
file_error(ms, errno, "error copying from pipe to temp file");
|
|
return -1;
|
|
case 0:
|
|
break;
|
|
default:
|
|
file_error(ms, errno, "error while writing to temp file");
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* We duplicate the file descriptor, because fclose on a
|
|
* tmpfile will delete the file, but any open descriptors
|
|
* can still access the phantom inode.
|
|
*/
|
|
if ((fd = dup2(tfd, fd)) == -1) {
|
|
file_error(ms, errno, "could not dup descriptor for temp file");
|
|
return -1;
|
|
}
|
|
(void)close(tfd);
|
|
if (lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) {
|
|
file_badseek(ms);
|
|
return -1;
|
|
}
|
|
return fd;
|
|
}
|
|
|
|
#ifdef HAVE_LIBZ
|
|
|
|
#define FHCRC (1 << 1)
|
|
#define FEXTRA (1 << 2)
|
|
#define FNAME (1 << 3)
|
|
#define FCOMMENT (1 << 4)
|
|
|
|
private size_t
|
|
uncompressgzipped(struct magic_set *ms, const unsigned char *old,
|
|
unsigned char **newch, size_t n)
|
|
{
|
|
unsigned char flg = old[3];
|
|
size_t data_start = 10;
|
|
z_stream z;
|
|
int rc;
|
|
|
|
if (flg & FEXTRA) {
|
|
if (data_start+1 >= n)
|
|
return 0;
|
|
data_start += 2 + old[data_start] + old[data_start + 1] * 256;
|
|
}
|
|
if (flg & FNAME) {
|
|
while(data_start < n && old[data_start])
|
|
data_start++;
|
|
data_start++;
|
|
}
|
|
if(flg & FCOMMENT) {
|
|
while(data_start < n && old[data_start])
|
|
data_start++;
|
|
data_start++;
|
|
}
|
|
if(flg & FHCRC)
|
|
data_start += 2;
|
|
|
|
if (data_start >= n)
|
|
return 0;
|
|
if ((*newch = (unsigned char *)malloc(HOWMANY + 1)) == NULL) {
|
|
return 0;
|
|
}
|
|
|
|
/* XXX: const castaway, via strchr */
|
|
z.next_in = (Bytef *)strchr((const char *)old + data_start,
|
|
old[data_start]);
|
|
z.avail_in = n - data_start;
|
|
z.next_out = *newch;
|
|
z.avail_out = HOWMANY;
|
|
z.zalloc = Z_NULL;
|
|
z.zfree = Z_NULL;
|
|
z.opaque = Z_NULL;
|
|
|
|
rc = inflateInit2(&z, -15);
|
|
if (rc != Z_OK) {
|
|
file_error(ms, 0, "zlib: %s", z.msg);
|
|
return 0;
|
|
}
|
|
|
|
rc = inflate(&z, Z_SYNC_FLUSH);
|
|
if (rc != Z_OK && rc != Z_STREAM_END) {
|
|
file_error(ms, 0, "zlib: %s", z.msg);
|
|
return 0;
|
|
}
|
|
|
|
n = (size_t)z.total_out;
|
|
inflateEnd(&z);
|
|
|
|
/* let's keep the nul-terminate tradition */
|
|
(*newch)[n++] = '\0';
|
|
|
|
return n;
|
|
}
|
|
#endif
|
|
|
|
private size_t
|
|
uncompressbuf(struct magic_set *ms, size_t method, const unsigned char *old,
|
|
unsigned char **newch, size_t n)
|
|
{
|
|
int fdin[2], fdout[2];
|
|
int r;
|
|
|
|
/* The buffer is NUL terminated, and we don't need that. */
|
|
n--;
|
|
|
|
#ifdef HAVE_LIBZ
|
|
if (method == 2)
|
|
return uncompressgzipped(ms, old, newch, n);
|
|
#endif
|
|
|
|
if (pipe(fdin) == -1 || pipe(fdout) == -1) {
|
|
file_error(ms, errno, "cannot create pipe");
|
|
return 0;
|
|
}
|
|
switch (fork()) {
|
|
case 0: /* child */
|
|
(void) close(0);
|
|
(void) dup(fdin[0]);
|
|
(void) close(fdin[0]);
|
|
(void) close(fdin[1]);
|
|
|
|
(void) close(1);
|
|
(void) dup(fdout[1]);
|
|
(void) close(fdout[0]);
|
|
(void) close(fdout[1]);
|
|
if (compr[method].silent)
|
|
(void) close(2);
|
|
|
|
execvp(compr[method].argv[0],
|
|
(char *const *)compr[method].argv);
|
|
exit(1);
|
|
/*NOTREACHED*/
|
|
case -1:
|
|
file_error(ms, errno, "could not fork");
|
|
return 0;
|
|
|
|
default: /* parent */
|
|
(void) close(fdin[0]);
|
|
(void) close(fdout[1]);
|
|
/* fork again, to avoid blocking because both pipes filled */
|
|
switch (fork()) {
|
|
case 0: /* child */
|
|
(void)close(fdout[0]);
|
|
if (swrite(fdin[1], old, n) != n)
|
|
exit(1);
|
|
exit(0);
|
|
/*NOTREACHED*/
|
|
|
|
case -1:
|
|
exit(1);
|
|
/*NOTREACHED*/
|
|
|
|
default: /* parent */
|
|
break;
|
|
}
|
|
(void) close(fdin[1]);
|
|
fdin[1] = -1;
|
|
if ((*newch = (unsigned char *) malloc(HOWMANY + 1)) == NULL) {
|
|
n = 0;
|
|
goto err;
|
|
}
|
|
if ((r = sread(fdout[0], *newch, HOWMANY)) <= 0) {
|
|
free(*newch);
|
|
n = 0;
|
|
newch[0] = '\0';
|
|
goto err;
|
|
} else {
|
|
n = r;
|
|
}
|
|
/* NUL terminate, as every buffer is handled here. */
|
|
(*newch)[n++] = '\0';
|
|
err:
|
|
if (fdin[1] != -1)
|
|
(void) close(fdin[1]);
|
|
(void) close(fdout[0]);
|
|
#ifdef WNOHANG
|
|
while (waitpid(-1, NULL, WNOHANG) != -1)
|
|
continue;
|
|
#else
|
|
(void)wait(NULL);
|
|
#endif
|
|
return n;
|
|
}
|
|
}
|