* Copyright (c) 2006 Stefan Traby <stefan@hello-penguin.com>

/*
* Copyright (c) 2006 Stefan Traby <[email protected]>
*
* Redistribution and use in source and binary forms, with or without modifica-
* tion, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* 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 ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
* CIAL, 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 OTH-
* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Alternatively, the contents of this file may be used under the terms of
* the GNU General Public License ("GPL") version 2 or any later version,
* in which case the provisions of the GPL are applicable instead of
* the above. If you wish to allow the use of your version of this file
* only under the terms of the GPL and not to allow others to use your
* version of this file under the BSD license, indicate your decision
* by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL. If you do not delete the
* provisions above, a recipient may use your version of this file under
* either the BSD or the GPL.
*/

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <limits.h>
#include "lzf.h"

#ifdef HAVE_GETOPT_H
# include <getopt.h>
#endif

#define BLOCKSIZE (1024 * 64 - 1)
#define MAX_BLOCKSIZE BLOCKSIZE

static off_t nr_read, nr_written;

static const char *imagename;
static enum { compress, uncompress, lzfcat } mode = compress;
static int verbose = 0;
static int force = 0;
static long blocksize = BLOCKSIZE;

#ifdef HAVE_GETOPT_LONG

struct option longopts[] = {
{"compress", 0, 0, 'c'},
{"decompress", 0, 0, 'd'},
{"uncompress", 0, 0, 'd'},
{"force", 0, 0, 'f'},
{"help", 0, 0, 'h'},
{"verbose", 0, 0, 'v'},
{"blocksize", 1, 0, 'b'},
{0, 0, 0, 0}
};

static const char *opt =
"-c --compress compress\n"
"-d --decompress decompress\n"
"-f --force force overwrite of output file\n"
"-h --help give this help\n" "-v --verbose verbose mode\n" "-b # --blocksize # set blocksize\n" "\n";

#else

static const char *opt =
"-c compress\n"
"-d decompress\n"
"-f force overwrite of output file\n"
"-h give this help\n"
"-v verbose mode\n"
"-b # set blocksize\n"
"\n";

#endif

static void
usage (int rc)
{
fprintf (stderr, "\n"
"lzf, a very lightweight compression/decompression utility written by Stefan Traby.\n"
"uses liblzf written by Marc Lehmann <[email protected]> You can find more info at\n"
"http://liblzf.plan9.de/\n"
"\n"
"usage: lzf [-dufhvb] [file ...]\n"
" unlzf [file ...]\n"
" lzfcat [file ...]\n"
"\n%s",
opt);

exit (rc);
}

static inline ssize_t
rread (int fd, void *buf, size_t len)
{
ssize_t rc = 0, offset = 0;
char *p = buf;

while (len && (rc = read (fd, &p[offset], len)) > 0)
{
offset += rc;
len -= rc;
}

nr_read += offset;

if (rc < 0)
return rc;

return offset;
}

/* returns 0 if all written else -1 */
static inline ssize_t
wwrite (int fd, void *buf, size_t len)
{
ssize_t rc;
char *b = buf;
size_t l = len;

while (l)
{
rc = write (fd, b, l);
if (rc < 0)
{
fprintf (stderr, "%s: write error: ", imagename);
perror ("");
return -1;
}

l -= rc;
b += rc;
}

nr_written += len;
return 0;
}

/*
* Anatomy: an lzf file consists of any number of blocks in the following format:
*
* \x00 EOF (optional)
* "ZV\0" 2-byte-usize <uncompressed data>
* "ZV\1" 2-byte-csize 2-byte-usize <compressed data>
* "ZV\2" 4-byte-crc32-0xdebb20e3 (NYI)
*/

#define TYPE0_HDR_SIZE 5
#define TYPE1_HDR_SIZE 7
#define MAX_HDR_SIZE 7
#define MIN_HDR_SIZE 5

static int
compress_fd (int from, int to)
{
ssize_t us, cs, len;
u8 buf1[MAX_BLOCKSIZE + MAX_HDR_SIZE + 16];
u8 buf2[MAX_BLOCKSIZE + MAX_HDR_SIZE + 16];
u8 *header;

nr_read = nr_written = 0;
while ((us = rread (from, &buf1[MAX_HDR_SIZE], blocksize)) > 0)
{
cs = lzf_compress (&buf1[MAX_HDR_SIZE], us, &buf2[MAX_HDR_SIZE], us > 4 ? us - 4 : us);
if (cs)
{
header = &buf2[MAX_HDR_SIZE - TYPE1_HDR_SIZE];
header[0] = 'Z';
header[1] = 'V';
header[2] = 1;
header[3] = cs >> 8;
header[4] = cs & 0xff;
header[5] = us >> 8;
header[6] = us & 0xff;
len = cs + TYPE1_HDR_SIZE;
}
else
{ // write uncompressed
header = &buf1[MAX_HDR_SIZE - TYPE0_HDR_SIZE];
header[0] = 'Z';
header[1] = 'V';
header[2] = 0;
header[3] = us >> 8;
header[4] = us & 0xff;
len = us + TYPE0_HDR_SIZE;
}

if (wwrite (to, header, len) == -1)
return -1;
}

return 0;
}

static int
uncompress_fd (int from, int to)
{
u8 header[MAX_HDR_SIZE];
u8 buf1[MAX_BLOCKSIZE + MAX_HDR_SIZE + 16];
u8 buf2[MAX_BLOCKSIZE + MAX_HDR_SIZE + 16];
u8 *p;
int l, rd;
ssize_t rc, cs, us, bytes, over = 0;

nr_read = nr_written = 0;
while (1)
{
rc = rread (from, header + over, MAX_HDR_SIZE - over);
if (rc < 0)
{
fprintf (stderr, "%s: read error: ", imagename);
perror ("");
return -1;
}

rc += over;
over = 0;
if (!rc || header[0] == 0)
return 0;

if (rc < MIN_HDR_SIZE || header[0] != 'Z' || header[1] != 'V')
{
fprintf (stderr, "%s: invalid data stream - magic not found or short header\n", imagename);
return -1;
}

switch (header[2])
{
case 0:
cs = -1;
us = (header[3] << 8) | header[4];
p = &header[TYPE0_HDR_SIZE];
break;
case 1:
if (rc < TYPE1_HDR_SIZE)
{
goto short_read;
}
cs = (header[3] << 8) | header[4];
us = (header[5] << 8) | header[6];
p = &header[TYPE1_HDR_SIZE];
break;
default:
fprintf (stderr, "%s: unknown blocktype\n", imagename);
return -1;
}

bytes = cs == -1 ? us : cs;
l = &header[rc] - p;

if (l > 0)
memcpy (buf1, p, l);

if (l > bytes)
{
over = l - bytes;
memmove (header, &p[bytes], over);
}

p = &buf1[l];
rd = bytes - l;
if (rd > 0)
if ((rc = rread (from, p, rd)) != rd)
goto short_read;

if (cs == -1)
{
if (wwrite (to, buf1, us))
return -1;
}
else
{
if (lzf_decompress (buf1, cs, buf2, us) != us)
{
fprintf (stderr, "%s: decompress: invalid stream - data corrupted\n", imagename);
return -1;
}

if (wwrite (to, buf2, us))
return -1;
}
}

return 0;

short_read:
fprintf (stderr, "%s: short data\n", imagename);
return -1;
}

static int
open_out (const char *name)
{
int fd;
int m = O_EXCL;

if (force)
m = 0;

fd = open (name, O_CREAT | O_WRONLY | O_TRUNC | m, 600);
#if defined(__MINGW32__)
_setmode(fd, _O_BINARY);
#endif
return fd;
}

static int
compose_name (const char *fname, char *oname)
{
char *p;

if (mode == compress)
{
if (strlen (fname) > PATH_MAX - 4)
{
fprintf (stderr, "%s: %s.lzf: name too long", imagename, fname);
return -1;
}

strcpy (oname, fname);
strcat (oname, ".lzf");
}
else
{
if (strlen (fname) > PATH_MAX)
{
fprintf (stderr, "%s: %s: name too long\n", imagename, fname);
return -1;
}

strcpy (oname, fname);
p = &oname[strlen (oname)] - 4;
if (p < oname || strcmp (p, ".lzf"))
{
fprintf (stderr, "%s: %s: unknown suffix\n", imagename, fname);
return -1;
}

*p = 0;
}

return 0;
}

static int
run_file (const char *fname)
{
int fd, fd2;
int rc;
struct stat mystat;
char oname[PATH_MAX + 1];

if (mode != lzfcat)
if (compose_name (fname, oname))
return -1;

#if !defined(__MINGW32__)
rc = lstat (fname, &mystat);
#else
rc = stat (fname, &mystat);
#endif
fd = open (fname, O_RDONLY);
#if defined(__MINGW32__)
_setmode(fd, _O_BINARY);
#endif
if (rc || fd == -1)
{
fprintf (stderr, "%s: %s: ", imagename, fname);
perror ("");
return -1;
}

if (!S_ISREG (mystat.st_mode))
{
fprintf (stderr, "%s: %s: not a regular file.\n", imagename, fname);
close (fd);
return -1;
}

if (mode == lzfcat)
{
rc = uncompress_fd (fd, 1);
close (fd);
return rc;
}

fd2 = open_out (oname);
if (fd2 == -1)
{
fprintf (stderr, "%s: %s: ", imagename, oname);
perror ("");
close (fd);
return -1;
}

if (mode == compress)
{
rc = compress_fd (fd, fd2);
if (!rc && verbose)
fprintf (stderr, "%s: %5.1f%% -- replaced with %s\n",
fname, nr_read == 0 ? 0 : 100.0 - nr_written / ((double) nr_read / 100.0), oname);
}
else
{
rc = uncompress_fd (fd, fd2);
if (!rc && verbose)
fprintf (stderr, "%s: %5.1f%% -- replaced with %s\n",
fname, nr_written == 0 ? 0 : 100.0 - nr_read / ((double) nr_written / 100.0), oname);
}

#if !defined(__MINGW32__)
fchmod (fd2, mystat.st_mode);
#else
chmod (oname, mystat.st_mode);
#endif
close (fd);
close (fd2);

if (!rc)
unlink (fname);

return rc;
}

int
main (int argc, char *argv[])
{
char *p = argv[0];
int optc;
int rc = 0;

errno = 0;
p = getenv ("LZF_BLOCKSIZE");
if (p)
{
blocksize = strtoul (p, 0, 0);
if (errno || !blocksize || blocksize > MAX_BLOCKSIZE)
blocksize = BLOCKSIZE;
}

p = strrchr (argv[0], '/');
imagename = p ? ++p : argv[0];

if (!strncmp (imagename, "un", 2) || !strncmp (imagename, "de", 2))
mode = uncompress;

if (strstr (imagename, "cat"))
mode = lzfcat;

#ifdef HAVE_GETOPT_LONG
while ((optc = getopt_long (argc, argv, "cdfhvb:", longopts, 0)) != -1)
#else
while ((optc = getopt (argc, argv, "cdfhvb:")) != -1)
#endif
{
switch (optc)
{
case 'c':
mode = compress;
break;
case 'd':
mode = uncompress;
break;
case 'f':
force = 1;
break;
case 'h':
usage (0);
break;
case 'v':
verbose = 1;
break;
case 'b':
errno = 0;
blocksize = strtoul (optarg, 0, 0);
if (errno || !blocksize || blocksize > MAX_BLOCKSIZE)
blocksize = BLOCKSIZE;
break;
default:
usage (1);
break;
}
}

if (optind == argc)
{ // stdin stdout
if (!force)
{
if ((mode == uncompress || mode == lzfcat) && isatty (0))
{
fprintf (stderr, "%s: compressed data not read from a terminal. Use -f to force decompression.\n", imagename);
exit (1);
}
if (mode == compress && isatty (1))
{
fprintf (stderr, "%s: compressed data not written to a terminal. Use -f to force compression.\n", imagename);
exit (1);
}
}

if (mode == compress)
rc = compress_fd (0, 1);
else
rc = uncompress_fd (0, 1);

exit (rc ? 1 : 0);
}

while (optind < argc)
rc |= run_file (argv[optind++]);

exit (rc ? 1 : 0);
}