/*
* 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.
*
* 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 "config.h"
#include "file.h"
#ifndef lint
FILE_RCSID("@(#)$File: compress.c,v 1.73 2014/01/05 15:55:21 christos Exp $")
#endif
#include "magic.h"
#include <stdlib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#ifndef PHP_WIN32
#include <sys/ioctl.h>
#endif
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#if defined(HAVE_SYS_TIME_H)
#include <sys/time.h>
#endif
#if defined(HAVE_ZLIB_H) && defined(HAVE_LIBZ)
#define BUILTIN_DECOMPRESS
#include <zlib.h>
#endif
#undef FIONREAD
private const struct {
const char magic[8];
size_t maglen;
const char *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 */
{ "PK\3\4", 4, { "gzip", "-cdq", NULL }, 1 }, /* pkzipped, */
/* ...only first file examined */
{ "BZh", 3, { "bzip2", "-cd", NULL }, 1 }, /* bzip2-ed */
{ "LZIP", 4, { "lzip", "-cdq", NULL }, 1 },
{ "\3757zXZ\0",6,{ "xz", "-cd", NULL }, 1 }, /* XZ Utils */
{ "LRZI", 4, { "lrzip", "-dqo-", NULL }, 1 }, /* LRZIP */
{ "\004\"M\030", 4, { "lz4", "-cd", NULL }, 1 }, /* LZ4 */
};
#define NODATA ((size_t)~0)
private ssize_t swrite(int, const void *, size_t);
#ifdef PHP_FILEINFO_UNCOMPRESS
private size_t uncompressbuf(struct magic_set *, int, size_t,
const unsigned char *, unsigned char **, size_t);
#ifdef BUILTIN_DECOMPRESS
private size_t uncompressgzipped(struct magic_set *, const unsigned char *,
unsigned char **, size_t);
#endif
protected int
file_zmagic(struct magic_set *ms, int fd, const char *name,
const unsigned char *buf, size_t nbytes)
{
unsigned char *newbuf = NULL;
size_t i, nsz;
int rv = 0;
int mime = ms->flags & MAGIC_MIME;
size_t ncompr;
if ((ms->flags & MAGIC_COMPRESS) == 0)
return 0;
ncompr = sizeof(compr) / sizeof(compr[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, fd, i, buf, &newbuf,
nbytes)) != NODATA) {
ms->flags &= ~MAGIC_COMPRESS;
rv = -1;
if (file_buffer(ms, -1, name, newbuf, nsz) == -1)
goto error;
if (mime == MAGIC_MIME || mime == 0) {
if (file_printf(ms, mime ?
" compressed-encoding=" : " (") == -1)
goto error;
if (file_buffer(ms, -1, NULL, buf, nbytes) == -1)
goto error;
if (!mime && file_printf(ms, ")") == -1)
goto error;
}
rv = 1;
break;
}
}
error:
if (newbuf)
efree(newbuf);
ms->flags |= MAGIC_COMPRESS;
return rv;
}
#endif
/*
* `safe' write for sockets and pipes.
*/
private ssize_t
swrite(int fd, const void *buf, size_t n)
{
ssize_t rv;
size_t rn = n;
do
switch (rv = write(fd, buf, n)) {
case -1:
if (errno == EINTR)
continue;
return -1;
default:
n -= rv;
buf = CAST(const char *, buf) + rv;
break;
}
while (n > 0);
return rn;
}
/*
* `safe' read for sockets and pipes.
*/
protected ssize_t
sread(int fd, void *buf, size_t n, int canbepipe)
{
ssize_t rv;
#ifdef FIONREAD
int t = 0;
#endif
size_t rn = n;
if (fd == STDIN_FILENO)
goto nocheck;
#ifdef FIONREAD
if (canbepipe && (ioctl(fd, FIONREAD, &t) == -1 || t == 0)) {
#ifdef FD_ZERO
ssize_t cnt;
for (cnt = 0;; cnt++) {
fd_set check;
struct timeval tout = {0, 100 * 1000};
int selrv;
FD_ZERO(&check);
FD_SET(fd, &check);
/*
* Avoid soft deadlock: do not read if there
* is nothing to read from sockets and pipes.
*/
selrv = select(fd + 1, &check, NULL, NULL, &tout);
if (selrv == -1) {
if (errno == EINTR || errno == EAGAIN)
continue;
} else if (selrv == 0 && cnt >= 5) {
return 0;
} else
break;
}
#endif
(void)ioctl(fd, FIONREAD, &t);
}
if (t > 0 && (size_t)t < n) {
n = t;
rn = n;
}
#endif
nocheck:
do
switch ((rv = FINFO_READ_FUNC(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];
ssize_t r;
int tfd;
(void)strlcpy(buf, "/tmp/file.XXXXXX", sizeof buf);
#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
{
int te;
tfd = mkstemp(buf);
te = errno;
(void)unlink(buf);
errno = te;
}
#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), 1)) > 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 (FINFO_LSEEK_FUNC(fd, (off_t)0, SEEK_SET) == (off_t)-1) {
file_badseek(ms);
return -1;
}
return fd;
}
#ifdef PHP_FILEINFO_UNCOMPRESS
#ifdef BUILTIN_DECOMPRESS
#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 = CAST(unsigned char *, emalloc(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 = CAST(uint32_t, (n - data_start));
z.next_out = *newch;
z.avail_out = HOWMANY;
z.zalloc = Z_NULL;
z.zfree = Z_NULL;
z.opaque = Z_NULL;
/* LINTED bug in header macro */
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;
(void)inflateEnd(&z);
/* let's keep the nul-terminate tradition */
(*newch)[n] = '\0';
return n;
}
#endif
private size_t
uncompressbuf(struct magic_set *ms, int fd, size_t method,
const unsigned char *old, unsigned char **newch, size_t n)
{
int fdin[2], fdout[2];
ssize_t r;
pid_t pid;
#ifdef BUILTIN_DECOMPRESS
/* FIXME: This doesn't cope with bzip2 */
if (method == 2)
return uncompressgzipped(ms, old, newch, n);
#endif
(void)fflush(stdout);
(void)fflush(stderr);
if ((fd != -1 && pipe(fdin) == -1) || pipe(fdout) == -1) {
file_error(ms, errno, "cannot create pipe");
return NODATA;
}
switch (pid = fork()) {
case 0: /* child */
(void) close(0);
if (fd != -1) {
(void) dup(fd);
(void) FINFO_LSEEK_FUNC(0, (off_t)0, SEEK_SET);
} else {
(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]);
#ifndef DEBUG
if (compr[method].silent)
(void)close(2);
#endif
(void)execvp(compr[method].argv[0],
(char *const *)(intptr_t)compr[method].argv);
#ifdef DEBUG
(void)fprintf(stderr, "exec `%s' failed (%s)\n",
compr[method].argv[0], strerror(errno));
#endif
exit(1);
/*NOTREACHED*/
case -1:
file_error(ms, errno, "could not fork");
return NODATA;
default: /* parent */
(void) close(fdout[1]);
if (fd == -1) {
(void) close(fdin[0]);
/*
* fork again, to avoid blocking because both
* pipes filled
*/
switch (fork()) {
case 0: /* child */
(void)close(fdout[0]);
if (swrite(fdin[1], old, n) != (ssize_t)n) {
#ifdef DEBUG
(void)fprintf(stderr,
"Write failed (%s)\n",
strerror(errno));
#endif
exit(1);
}
exit(0);
/*NOTREACHED*/
case -1:
#ifdef DEBUG
(void)fprintf(stderr, "Fork failed (%s)\n",
strerror(errno));
#endif
exit(1);
/*NOTREACHED*/
default: /* parent */
break;
}
(void) close(fdin[1]);
fdin[1] = -1;
}
*newch = (unsigned char *) emalloc(HOWMANY + 1);
if ((r = sread(fdout[0], *newch, HOWMANY, 0)) <= 0) {
#ifdef DEBUG
(void)fprintf(stderr, "Read failed (%s)\n",
strerror(errno));
#endif
efree(*newch);
n = 0;
*newch = NULL;
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(pid, NULL, WNOHANG) != -1)
continue;
#else
(void)wait(NULL);
#endif
(void) close(fdin[0]);
return n;
}
}
#endif /* if PHP_FILEINFO_UNCOMPRESS */