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php-src/ext/fileinfo/libmagic/compress.c
Niels Dossche 37dbad8fcd Upgrade to file 5.46
2025-02-15 12:53:07 +01:00

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/*
* 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 "file.h"
#ifndef lint
FILE_RCSID("@(#)$File: compress.c,v 1.158 2024/11/10 16:52:27 christos Exp $")
#endif
#include "magic.h"
#include <stdlib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SPAWN_H
#include <spawn.h>
#endif
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <stdarg.h>
#include <signal.h>
#ifndef HAVE_SIG_T
typedef void (*sig_t)(int);
#endif /* HAVE_SIG_T */
#ifdef HAVE_SYS_IOCTL_H
#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(PHP_FILEINFO_UNCOMPRESS)
#define BUILTIN_DECOMPRESS
#include <zlib.h>
#endif
#undef FIONREAD
#if defined(PHP_FILEINFO_UNCOMPRESS)
#define BUILTIN_BZLIB
#include <bzlib.h>
#endif
#if defined(HAVE_LZMA_H) && defined(XZLIBSUPPORT)
#define BUILTIN_XZLIB
#include <lzma.h>
#endif
#if defined(HAVE_ZSTD_H) && defined(ZSTDLIBSUPPORT)
#define BUILTIN_ZSTDLIB
#include <zstd.h>
#include <zstd_errors.h>
#endif
#if defined(HAVE_LZLIB_H) && defined(LZLIBSUPPORT)
#define BUILTIN_LZLIB
#include <lzlib.h>
#endif
#ifdef DEBUG
int tty = -1;
#define DPRINTF(...) do { \
if (tty == -1) \
tty = open("/dev/tty", O_RDWR); \
if (tty == -1) \
abort(); \
dprintf(tty, __VA_ARGS__); \
} while (/*CONSTCOND*/0)
#else
#define DPRINTF(...)
#endif
#ifdef ZLIBSUPPORT
/*
* The following python code is not really used because ZLIBSUPPORT is only
* defined if we have a built-in zlib, and the built-in zlib handles that.
* That is not true for android where we have zlib.h and not -lz.
*/
static const char zlibcode[] =
"import sys, zlib; sys.stdout.write(zlib.decompress(sys.stdin.read()))";
static const char *zlib_args[] = { "python", "-c", zlibcode, NULL };
static int
zlibcmp(const unsigned char *buf)
{
unsigned short x = 1;
unsigned char *s = CAST(unsigned char *, CAST(void *, &x));
if ((buf[0] & 0xf) != 8 || (buf[0] & 0x80) != 0)
return 0;
if (s[0] != 1) /* endianness test */
x = buf[0] | (buf[1] << 8);
else
x = buf[1] | (buf[0] << 8);
if (x % 31)
return 0;
return 1;
}
#endif
#ifdef PHP_FILEINFO_UNCOMPRESS
static int
lzmacmp(const unsigned char *buf)
{
if (buf[0] != 0x5d || buf[1] || buf[2])
return 0;
if (buf[12] && buf[12] != 0xff)
return 0;
return 1;
}
#define gzip_flags "-cd"
#define lzip_flags gzip_flags
static const char *gzip_args[] = {
"gzip", gzip_flags, NULL
};
static const char *uncompress_args[] = {
"uncompress", "-c", NULL
};
static const char *bzip2_args[] = {
"bzip2", "-cd", NULL
};
static const char *lzip_args[] = {
"lzip", lzip_flags, NULL
};
static const char *xz_args[] = {
"xz", "-cd", NULL
};
static const char *lrzip_args[] = {
"lrzip", "-qdf", "-", NULL
};
static const char *lz4_args[] = {
"lz4", "-cd", NULL
};
static const char *zstd_args[] = {
"zstd", "-cd", NULL
};
#define do_zlib NULL
#define do_bzlib NULL
file_private const struct {
union {
const char *magic;
int (*func)(const unsigned char *);
} u;
int maglen;
const char **argv;
void *unused;
} compr[] = {
#define METH_FROZEN 2
#define METH_BZIP 7
#define METH_XZ 9
#define METH_LZIP 8
#define METH_LRZIP 10
#define METH_ZSTD 12
#define METH_LZMA 13
#define METH_ZLIB 14
{ { .magic = "\037\235" }, 2, gzip_args, NULL }, /* 0, compressed */
/* Uncompress can get stuck; so use gzip first if we have it
* Idea from Damien Clark, thanks! */
{ { .magic = "\037\235" }, 2, uncompress_args, NULL },/* 1, compressed */
{ { .magic = "\037\213" }, 2, gzip_args, do_zlib },/* 2, gzipped */
{ { .magic = "\037\236" }, 2, gzip_args, NULL }, /* 3, frozen */
{ { .magic = "\037\240" }, 2, gzip_args, NULL }, /* 4, SCO LZH */
/* the standard pack utilities do not accept standard input */
{ { .magic = "\037\036" }, 2, gzip_args, NULL }, /* 5, packed */
{ { .magic = "PK\3\4" }, 4, gzip_args, NULL }, /* 6, pkziped */
/* ...only first file examined */
{ { .magic = "BZh" }, 3, bzip2_args, do_bzlib },/* 7, bzip2-ed */
{ { .magic = "LZIP" }, 4, lzip_args, NULL }, /* 8, lzip-ed */
{ { .magic = "\3757zXZ\0" },6, xz_args, NULL }, /* 9, XZ Util */
{ { .magic = "LRZI" }, 4, lrzip_args, NULL }, /* 10, LRZIP */
{ { .magic = "\004\"M\030" },4, lz4_args, NULL }, /* 11, LZ4 */
{ { .magic = "\x28\xB5\x2F\xFD" }, 4, zstd_args, NULL },/* 12, zstd */
{ { .func = lzmacmp }, -13, xz_args, NULL }, /* 13, lzma */
#ifdef ZLIBSUPPORT
{ { .func = zlibcmp }, -2, zlib_args, NULL }, /* 14, zlib */
#endif
};
#define OKDATA 0
#define NODATA 1
#define ERRDATA 2
file_private ssize_t swrite(int, const void *, size_t);
#if HAVE_FORK
file_private size_t ncompr = __arraycount(compr);
file_private int uncompressbuf(int, size_t, size_t, int, const unsigned char *,
unsigned char **, size_t *);
#ifdef BUILTIN_DECOMPRESS
file_private int uncompresszlib(const unsigned char *, unsigned char **, size_t,
size_t *, int);
file_private int uncompressgzipped(const unsigned char *, unsigned char **, size_t,
size_t *, int);
#endif
#ifdef BUILTIN_BZLIB
file_private int uncompressbzlib(const unsigned char *, unsigned char **, size_t,
size_t *, int);
#endif
#ifdef BUILTIN_XZLIB
file_private int uncompressxzlib(const unsigned char *, unsigned char **, size_t,
size_t *, int);
#endif
#ifdef BUILTIN_ZSTDLIB
file_private int uncompresszstd(const unsigned char *, unsigned char **, size_t,
size_t *, int);
#endif
#ifdef BUILTIN_LZLIB
file_private int uncompresslzlib(const unsigned char *, unsigned char **, size_t,
size_t *, int);
#endif
static int makeerror(unsigned char **, size_t *, const char *, ...)
__attribute__((__format__(__printf__, 3, 4)));
file_private const char *methodname(size_t);
file_private int
format_decompression_error(struct magic_set *ms, size_t i, unsigned char *buf)
{
unsigned char *p;
int mime = ms->flags & MAGIC_MIME;
if (!mime)
return file_printf(ms, "ERROR:[%s: %s]", methodname(i), buf);
for (p = buf; *p; p++)
if (!isalnum(*p))
*p = '-';
return file_printf(ms, "application/x-decompression-error-%s-%s",
methodname(i), buf);
}
file_protected int
file_zmagic(struct magic_set *ms, const struct buffer *b, const char *name)
{
unsigned char *newbuf = NULL;
size_t i, nsz;
char *rbuf;
file_pushbuf_t *pb;
int urv, prv, rv = 0;
int mime = ms->flags & MAGIC_MIME;
int fd = b->fd;
const unsigned char *buf = CAST(const unsigned char *, b->fbuf);
size_t nbytes = b->flen;
int sa_saved = 0;
struct sigaction sig_act;
if ((ms->flags & MAGIC_COMPRESS) == 0)
return 0;
for (i = 0; i < ncompr; i++) {
int zm;
if (nbytes < CAST(size_t, abs(compr[i].maglen)))
continue;
if (compr[i].maglen < 0) {
zm = (*compr[i].u.func)(buf);
} else {
zm = memcmp(buf, compr[i].u.magic,
CAST(size_t, compr[i].maglen)) == 0;
}
if (!zm)
continue;
/* Prevent SIGPIPE death if child dies unexpectedly */
if (!sa_saved) {
//We can use sig_act for both new and old, but
struct sigaction new_act;
memset(&new_act, 0, sizeof(new_act));
new_act.sa_handler = SIG_IGN;
sa_saved = sigaction(SIGPIPE, &new_act, &sig_act) != -1;
}
nsz = nbytes;
efree(newbuf);
urv = uncompressbuf(fd, ms->bytes_max, i,
(ms->flags & MAGIC_NO_COMPRESS_FORK), buf, &newbuf, &nsz);
DPRINTF("uncompressbuf = %d, %s, %" SIZE_T_FORMAT "u\n", urv,
(char *)newbuf, nsz);
switch (urv) {
case OKDATA:
case ERRDATA:
ms->flags &= ~MAGIC_COMPRESS;
if (urv == ERRDATA)
prv = format_decompression_error(ms, i, newbuf);
else
prv = file_buffer(ms, NULL, NULL, name, newbuf,
nsz);
if (prv == -1)
goto error;
rv = 1;
if ((ms->flags & MAGIC_COMPRESS_TRANSP) != 0)
goto out;
if (mime != MAGIC_MIME && mime != 0)
goto out;
if ((file_printf(ms,
mime ? " compressed-encoding=" : " (")) == -1)
goto error;
if ((pb = file_push_buffer(ms)) == NULL)
goto error;
/*
* XXX: If file_buffer fails here, we overwrite
* the compressed text. FIXME.
*/
if (file_buffer(ms, NULL, NULL, NULL, buf, nbytes) == -1)
{
if (file_pop_buffer(ms, pb) != NULL)
abort();
goto error;
}
if ((rbuf = file_pop_buffer(ms, pb)) != NULL) {
if (file_printf(ms, "%s", rbuf) == -1) {
efree(rbuf);
goto error;
}
efree(rbuf);
}
if (!mime && file_printf(ms, ")") == -1)
goto error;
/*FALLTHROUGH*/
case NODATA:
break;
default:
abort();
/*NOTREACHED*/
error:
rv = -1;
break;
}
}
out:
DPRINTF("rv = %d\n", rv);
if (sa_saved && sig_act.sa_handler != SIG_IGN)
(void)sigaction(SIGPIPE, &sig_act, NULL);
if (newbuf)
efree(newbuf);
ms->flags |= MAGIC_COMPRESS;
DPRINTF("Zmagic returns %d\n", rv);
return rv;
}
#endif
/*
* `safe' write for sockets and pipes.
*/
file_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.
*/
file_protected ssize_t
sread(int fd, void *buf, size_t n, int canbepipe __attribute__((__unused__)))
{
ssize_t rv;
#if defined(FIONREAD) && !defined(__MINGW32__)
int t = 0;
#endif
size_t rn = n;
if (fd == STDIN_FILENO)
goto nocheck;
#if defined(FIONREAD) && !defined(__MINGW32__)
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 && CAST(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 = CAST(char *, CCAST(void *, buf)) + rv;
break;
}
while (n > 0);
return rn;
}
file_protected int
file_pipe2file(struct magic_set *ms, int fd, const void *startbuf,
size_t nbytes)
{
char buf[4096];
ssize_t r;
int tfd;
#ifdef WIN32
const char *t;
buf[0] = '\0';
if ((t = getenv("TEMP")) != NULL)
(void)strlcpy(buf, t, sizeof(buf));
else if ((t = getenv("TMP")) != NULL)
(void)strlcpy(buf, t, sizeof(buf));
else if ((t = getenv("TMPDIR")) != NULL)
(void)strlcpy(buf, t, sizeof(buf));
if (buf[0] != '\0')
(void)strlcat(buf, "/", sizeof(buf));
(void)strlcat(buf, "file.XXXXXX", sizeof(buf));
#else
(void)strlcpy(buf, "/tmp/file.XXXXXX", sizeof(buf));
#endif
#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;
mode_t ou = umask(0);
tfd = mkstemp(buf);
(void)umask(ou);
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) != CAST(ssize_t, nbytes))
r = 1;
else {
while ((r = sread(fd, buf, sizeof(buf), 1)) > 0)
if (swrite(tfd, buf, CAST(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, (zend_off_t)0, SEEK_SET) == (zend_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)
file_private int
uncompressgzipped(const unsigned char *old, unsigned char **newch,
size_t bytes_max, size_t *n, int extra __attribute__((__unused__)))
{
unsigned char flg;
size_t data_start = 10;
if (*n < 4) {
goto err;
}
flg = old[3];
if (flg & FEXTRA) {
if (data_start + 1 >= *n)
goto err;
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)
goto err;
*n -= data_start;
old += data_start;
return uncompresszlib(old, newch, bytes_max, n, 0);
err:
return makeerror(newch, n, "File too short");
}
file_private int
uncompresszlib(const unsigned char *old, unsigned char **newch,
size_t bytes_max, size_t *n, int zlib)
{
int rc;
z_stream z;
DPRINTF("builtin zlib decompression\n");
z.next_in = CCAST(Bytef *, old);
z.avail_in = CAST(uint32_t, *n);
z.next_out = *newch;
z.avail_out = CAST(unsigned int, bytes_max);
z.zalloc = Z_NULL;
z.zfree = Z_NULL;
z.opaque = Z_NULL;
/* LINTED bug in header macro */
rc = zlib ? inflateInit(&z) : inflateInit2(&z, -15);
if (rc != Z_OK)
goto err;
rc = inflate(&z, Z_SYNC_FLUSH);
if (rc != Z_OK && rc != Z_STREAM_END) {
inflateEnd(&z);
goto err;
}
*n = CAST(size_t, z.total_out);
rc = inflateEnd(&z);
if (rc != Z_OK)
goto err;
/* let's keep the nul-terminate tradition */
(*newch)[*n] = '\0';
return OKDATA;
err:
return makeerror(newch, n, "%s", z.msg ? z.msg : zError(rc));
}
#endif
#ifdef BUILTIN_BZLIB
file_private int
uncompressbzlib(const unsigned char *old, unsigned char **newch,
size_t bytes_max, size_t *n, int extra __attribute__((__unused__)))
{
int rc;
bz_stream bz;
DPRINTF("builtin bzlib decompression\n");
memset(&bz, 0, sizeof(bz));
rc = BZ2_bzDecompressInit(&bz, 0, 0);
if (rc != BZ_OK)
goto err;
bz.next_in = CCAST(char *, RCAST(const char *, old));
bz.avail_in = CAST(uint32_t, *n);
bz.next_out = RCAST(char *, *newch);
bz.avail_out = CAST(unsigned int, bytes_max);
rc = BZ2_bzDecompress(&bz);
if (rc != BZ_OK && rc != BZ_STREAM_END) {
BZ2_bzDecompressEnd(&bz);
goto err;
}
/* Assume byte_max is within 32bit */
/* assert(bz.total_out_hi32 == 0); */
*n = CAST(size_t, bz.total_out_lo32);
rc = BZ2_bzDecompressEnd(&bz);
if (rc != BZ_OK)
goto err;
/* let's keep the nul-terminate tradition */
(*newch)[*n] = '\0';
return OKDATA;
err:
return makeerror(newch, n, "bunzip error %d", rc);
}
#endif
#ifdef BUILTIN_XZLIB
file_private int
uncompressxzlib(const unsigned char *old, unsigned char **newch,
size_t bytes_max, size_t *n, int extra __attribute__((__unused__)))
{
int rc;
lzma_stream xz;
DPRINTF("builtin xzlib decompression\n");
memset(&xz, 0, sizeof(xz));
rc = lzma_auto_decoder(&xz, UINT64_MAX, 0);
if (rc != LZMA_OK)
goto err;
xz.next_in = CCAST(const uint8_t *, old);
xz.avail_in = CAST(uint32_t, *n);
xz.next_out = RCAST(uint8_t *, *newch);
xz.avail_out = CAST(unsigned int, bytes_max);
rc = lzma_code(&xz, LZMA_RUN);
if (rc != LZMA_OK && rc != LZMA_STREAM_END) {
lzma_end(&xz);
goto err;
}
*n = CAST(size_t, xz.total_out);
lzma_end(&xz);
/* let's keep the nul-terminate tradition */
(*newch)[*n] = '\0';
return OKDATA;
err:
return makeerror(newch, n, "unxz error %d", rc);
}
#endif
#ifdef BUILTIN_ZSTDLIB
file_private int
uncompresszstd(const unsigned char *old, unsigned char **newch,
size_t bytes_max, size_t *n, int extra __attribute__((__unused__)))
{
size_t rc;
ZSTD_DStream *zstd;
ZSTD_inBuffer in;
ZSTD_outBuffer out;
DPRINTF("builtin zstd decompression\n");
if ((zstd = ZSTD_createDStream()) == NULL) {
return makeerror(newch, n, "No ZSTD decompression stream, %s",
strerror(errno));
}
rc = ZSTD_DCtx_reset(zstd, ZSTD_reset_session_only);
if (ZSTD_isError(rc))
goto err;
in.src = CCAST(const void *, old);
in.size = *n;
in.pos = 0;
out.dst = RCAST(void *, *newch);
out.size = bytes_max;
out.pos = 0;
rc = ZSTD_decompressStream(zstd, &out, &in);
if (ZSTD_isError(rc))
goto err;
*n = out.pos;
ZSTD_freeDStream(zstd);
/* let's keep the nul-terminate tradition */
(*newch)[*n] = '\0';
return OKDATA;
err:
ZSTD_freeDStream(zstd);
return makeerror(newch, n, "zstd error %d", ZSTD_getErrorCode(rc));
}
#endif
#ifdef BUILTIN_LZLIB
file_private int
uncompresslzlib(const unsigned char *old, unsigned char **newch,
size_t bytes_max, size_t *n, int extra __attribute__((__unused__)))
{
enum LZ_Errno err;
size_t old_remaining = *n;
size_t new_remaining = bytes_max;
size_t total_read = 0;
unsigned char *bufp;
struct LZ_Decoder *dec;
bufp = *newch;
DPRINTF("builtin lzlib decompression\n");
dec = LZ_decompress_open();
if (!dec) {
return makeerror(newch, n, "unable to allocate LZ_Decoder");
}
if (LZ_decompress_errno(dec) != LZ_ok)
goto err;
for (;;) {
// LZ_decompress_read() stops at member boundaries, so we may
// have more than one successful read after writing all data
// we have.
if (old_remaining > 0) {
int wr = LZ_decompress_write(dec, old, old_remaining);
if (wr < 0)
goto err;
old_remaining -= wr;
old += wr;
}
int rd = LZ_decompress_read(dec, bufp, new_remaining);
if (rd > 0) {
new_remaining -= rd;
bufp += rd;
total_read += rd;
}
if (rd < 0 || LZ_decompress_errno(dec) != LZ_ok)
goto err;
if (new_remaining == 0)
break;
if (old_remaining == 0 && rd == 0)
break;
}
LZ_decompress_close(dec);
*n = total_read;
/* let's keep the nul-terminate tradition */
*bufp = '\0';
return OKDATA;
err:
err = LZ_decompress_errno(dec);
LZ_decompress_close(dec);
return makeerror(newch, n, "lzlib error: %s", LZ_strerror(err));
}
#endif
static int
makeerror(unsigned char **buf, size_t *len, const char *fmt, ...)
{
char *msg;
va_list ap;
int rv;
DPRINTF("Makeerror %s\n", fmt);
free(*buf);
va_start(ap, fmt);
rv = vasprintf(&msg, fmt, ap);
va_end(ap);
if (rv < 0) {
DPRINTF("Makeerror failed");
*buf = NULL;
*len = 0;
return NODATA;
}
*buf = RCAST(unsigned char *, msg);
*len = strlen(msg);
return ERRDATA;
}
static void
closefd(int *fd, size_t i)
{
if (fd[i] == -1)
return;
(void) close(fd[i]);
fd[i] = -1;
}
static void
closep(int *fd)
{
size_t i;
for (i = 0; i < 2; i++)
closefd(fd, i);
}
static void
movedesc(void *v, int i, int fd)
{
if (fd == i)
return; /* "no dup was necessary" */
#ifdef HAVE_POSIX_SPAWNP
posix_spawn_file_actions_t *fa = RCAST(posix_spawn_file_actions_t *, v);
posix_spawn_file_actions_adddup2(fa, fd, i);
posix_spawn_file_actions_addclose(fa, fd);
#else
if (dup2(fd, i) == -1) {
DPRINTF("dup(%d, %d) failed (%s)\n", fd, i, strerror(errno));
exit(EXIT_FAILURE);
}
close(v ? fd : fd);
#endif
}
static void
closedesc(void *v, int fd)
{
#ifdef HAVE_POSIX_SPAWNP
posix_spawn_file_actions_t *fa = RCAST(posix_spawn_file_actions_t *, v);
posix_spawn_file_actions_addclose(fa, fd);
#else
close(v ? fd : fd);
#endif
}
static void
handledesc(void *v, int fd, int fdp[3][2])
{
if (fd != -1) {
(void) lseek(fd, CAST(off_t, 0), SEEK_SET);
movedesc(v, STDIN_FILENO, fd);
} else {
movedesc(v, STDIN_FILENO, fdp[STDIN_FILENO][0]);
if (fdp[STDIN_FILENO][1] > 2)
closedesc(v, fdp[STDIN_FILENO][1]);
}
file_clear_closexec(STDIN_FILENO);
///FIXME: if one of the fdp[i][j] is 0 or 1, this can bomb spectacularly
movedesc(v, STDOUT_FILENO, fdp[STDOUT_FILENO][1]);
if (fdp[STDOUT_FILENO][0] > 2)
closedesc(v, fdp[STDOUT_FILENO][0]);
file_clear_closexec(STDOUT_FILENO);
movedesc(v, STDERR_FILENO, fdp[STDERR_FILENO][1]);
if (fdp[STDERR_FILENO][0] > 2)
closedesc(v, fdp[STDERR_FILENO][0]);
file_clear_closexec(STDERR_FILENO);
}
static pid_t
writechild(int fd, const void *old, size_t n)
{
pid_t pid;
/*
* fork again, to avoid blocking because both
* pipes filled
*/
pid = fork();
if (pid == -1) {
DPRINTF("Fork failed (%s)\n", strerror(errno));
return -1;
}
if (pid == 0) {
/* child */
if (swrite(fd, old, n) != CAST(ssize_t, n)) {
DPRINTF("Write failed (%s)\n", strerror(errno));
exit(EXIT_FAILURE);
}
exit(EXIT_SUCCESS);
}
/* parent */
return pid;
}
static ssize_t
filter_error(unsigned char *ubuf, ssize_t n)
{
char *p;
char *buf;
ubuf[n] = '\0';
buf = RCAST(char *, ubuf);
while (isspace(CAST(unsigned char, *buf)))
buf++;
DPRINTF("Filter error[[[%s]]]\n", buf);
if ((p = strchr(CAST(char *, buf), '\n')) != NULL)
*p = '\0';
if ((p = strchr(CAST(char *, buf), ';')) != NULL)
*p = '\0';
if ((p = strrchr(CAST(char *, buf), ':')) != NULL) {
++p;
while (isspace(CAST(unsigned char, *p)))
p++;
n = strlen(p);
memmove(ubuf, p, CAST(size_t, n + 1));
}
DPRINTF("Filter error after[[[%s]]]\n", (char *)ubuf);
if (islower(*ubuf))
*ubuf = toupper(*ubuf);
return n;
}
file_private const char *
methodname(size_t method)
{
switch (method) {
#ifdef BUILTIN_DECOMPRESS
case METH_FROZEN:
case METH_ZLIB:
return "zlib";
#endif
#ifdef BUILTIN_BZLIB
case METH_BZIP:
return "bzlib";
#endif
#ifdef BUILTIN_XZLIB
case METH_XZ:
case METH_LZMA:
return "xzlib";
#endif
#ifdef BUILTIN_ZSTDLIB
case METH_ZSTD:
return "zstd";
#endif
#ifdef BUILTIN_LZLIB
case METH_LZIP:
return "lzlib";
#endif
default:
return compr[method].argv[0];
}
}
file_private int (*
getdecompressor(size_t method))(const unsigned char *, unsigned char **, size_t,
size_t *, int)
{
switch (method) {
#ifdef BUILTIN_DECOMPRESS
case METH_FROZEN:
return uncompressgzipped;
case METH_ZLIB:
return uncompresszlib;
#endif
#ifdef BUILTIN_BZLIB
case METH_BZIP:
return uncompressbzlib;
#endif
#ifdef BUILTIN_XZLIB
case METH_XZ:
case METH_LZMA:
return uncompressxzlib;
#endif
#ifdef BUILTIN_ZSTDLIB
case METH_ZSTD:
return uncompresszstd;
#endif
#ifdef BUILTIN_LZLIB
case METH_LZIP:
return uncompresslzlib;
#endif
default:
return NULL;
}
}
file_private int
uncompressbuf(int fd, size_t bytes_max, size_t method, int nofork,
const unsigned char *old, unsigned char **newch, size_t* n)
{
int fdp[3][2];
int status, rv, w;
pid_t pid;
pid_t writepid = -1;
size_t i;
ssize_t r, re;
char *const *args;
#ifdef HAVE_POSIX_SPAWNP
posix_spawn_file_actions_t fa;
#endif
int (*decompress)(const unsigned char *, unsigned char **,
size_t, size_t *, int) = getdecompressor(method);
*newch = CAST(unsigned char *, emalloc(bytes_max + 1));
if (*newch == NULL)
return makeerror(newch, n, "No buffer, %s", strerror(errno));
if (decompress) {
if (nofork) {
return makeerror(newch, n,
"Fork is required to uncompress, but disabled");
}
return (*decompress)(old, newch, bytes_max, n, 1);
}
(void)fflush(stdout);
(void)fflush(stderr);
for (i = 0; i < __arraycount(fdp); i++)
fdp[i][0] = fdp[i][1] = -1;
/*
* There are multithreaded users who run magic_file()
* from dozens of threads. If two parallel magic_file() calls
* analyze two large compressed files, both will spawn
* an uncompressing child here, which writes out uncompressed data.
* We read some portion, then close the pipe, then waitpid() the child.
* If uncompressed data is larger, child should get EPIPE and exit.
* However, with *parallel* calls OTHER child may unintentionally
* inherit pipe fds, thus keeping pipe open and making writes in
* our child block instead of failing with EPIPE!
* (For the bug to occur, two threads must mutually inherit their pipes,
* and both must have large outputs. Thus it happens not that often).
* To avoid this, be sure to create pipes with O_CLOEXEC.
*/
if ((fd == -1 && file_pipe_closexec(fdp[STDIN_FILENO]) == -1) ||
file_pipe_closexec(fdp[STDOUT_FILENO]) == -1 ||
file_pipe_closexec(fdp[STDERR_FILENO]) == -1) {
closep(fdp[STDIN_FILENO]);
closep(fdp[STDOUT_FILENO]);
return makeerror(newch, n, "Cannot create pipe, %s",
strerror(errno));
}
args = RCAST(char *const *, RCAST(intptr_t, compr[method].argv));
#ifdef HAVE_POSIX_SPAWNP
posix_spawn_file_actions_init(&fa);
handledesc(&fa, fd, fdp);
DPRINTF("Executing %s\n", compr[method].argv[0]);
status = posix_spawnp(&pid, compr[method].argv[0], &fa, NULL,
args, NULL);
posix_spawn_file_actions_destroy(&fa);
if (status == -1) {
return makeerror(newch, n, "Cannot posix_spawn `%s', %s",
compr[method].argv[0], strerror(errno));
}
#else
/* For processes with large mapped virtual sizes, vfork
* may be _much_ faster (10-100 times) than fork.
*/
pid = vfork();
if (pid == -1) {
return makeerror(newch, n, "Cannot vfork, %s",
strerror(errno));
}
if (pid == 0) {
/* child */
/* Note: we are after vfork, do not modify memory
* in a way which confuses parent. In particular,
* do not modify fdp[i][j].
*/
handledesc(NULL, fd, fdp);
DPRINTF("Executing %s\n", compr[method].argv[0]);
(void)execvp(compr[method].argv[0], args);
dprintf(STDERR_FILENO, "exec `%s' failed, %s",
compr[method].argv[0], strerror(errno));
_exit(EXIT_FAILURE); /* _exit(), not exit(), because of vfork */
}
#endif
/* parent */
/* Close write sides of child stdout/err pipes */
for (i = 1; i < __arraycount(fdp); i++)
closefd(fdp[i], 1);
/* Write the buffer data to child stdin, if we don't have fd */
if (fd == -1) {
closefd(fdp[STDIN_FILENO], 0);
writepid = writechild(fdp[STDIN_FILENO][1], old, *n);
if (writepid == (pid_t)-1) {
rv = makeerror(newch, n, "Write to child failed, %s",
strerror(errno));
DPRINTF("Write to child failed\n");
goto err;
}
closefd(fdp[STDIN_FILENO], 1);
}
rv = OKDATA;
r = sread(fdp[STDOUT_FILENO][0], *newch, bytes_max, 0);
DPRINTF("read got %zd\n", r);
if (r < 0) {
rv = ERRDATA;
DPRINTF("Read stdout failed %d (%s)\n", fdp[STDOUT_FILENO][0],
strerror(errno));
goto err;
}
if (CAST(size_t, r) == bytes_max) {
/*
* close fd so that the child exits with sigpipe and ignore
* errors, otherwise we risk the child blocking and never
* exiting.
*/
DPRINTF("Closing stdout for bytes_max\n");
closefd(fdp[STDOUT_FILENO], 0);
goto ok;
}
if ((re = sread(fdp[STDERR_FILENO][0], *newch, bytes_max, 0)) > 0) {
DPRINTF("Got stuff from stderr %s\n", *newch);
rv = ERRDATA;
r = filter_error(*newch, r);
goto ok;
}
if (re == 0)
goto ok;
rv = makeerror(newch, n, "Read stderr failed, %s",
strerror(errno));
goto err;
ok:
*n = r;
/* NUL terminate, as every buffer is handled here. */
(*newch)[*n] = '\0';
err:
closefd(fdp[STDIN_FILENO], 1);
closefd(fdp[STDOUT_FILENO], 0);
closefd(fdp[STDERR_FILENO], 0);
w = waitpid(pid, &status, 0);
wait_err:
if (w == -1) {
rv = makeerror(newch, n, "Wait failed, %s", strerror(errno));
DPRINTF("Child wait return %#x\n", status);
} else if (!WIFEXITED(status)) {
DPRINTF("Child not exited (%#x)\n", status);
} else if (WEXITSTATUS(status) != 0) {
DPRINTF("Child exited (%#x)\n", WEXITSTATUS(status));
}
if (writepid > 0) {
/* _After_ we know decompressor has exited, our input writer
* definitely will exit now (at worst, writing fails in it,
* since output fd is closed now on the reading size).
*/
w = waitpid(writepid, &status, 0);
writepid = -1;
goto wait_err;
}
closefd(fdp[STDIN_FILENO], 0); //why? it is already closed here!
DPRINTF("Returning %p n=%" SIZE_T_FORMAT "u rv=%d\n", *newch, *n, rv);
return rv;
}
#endif
#endif
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