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/*
* Copyright (c) 2010, 2013, 2022
* Phillip Lougher <phillip@squashfs.org.uk>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2,
* or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* lzma_xz_wrapper.c
*
* Support for LZMA1 compression using XZ Utils liblzma http://tukaani.org/xz/
*/
#include <stdio.h>
#include <string.h>
#include <lzma.h>
#include "squashfs_fs.h"
#include "compressor.h"
#define LZMA_PROPS_SIZE 5
#define LZMA_UNCOMP_SIZE 8
#define LZMA_HEADER_SIZE (LZMA_PROPS_SIZE + LZMA_UNCOMP_SIZE)
#define LZMA_OPTIONS 5
#define MEMLIMIT (32 * 1024 * 1024)
static int lzma_compress(void *dummy, void *dest, void *src, int size,
int block_size, int *error)
{
unsigned char *d = (unsigned char *) dest;
lzma_options_lzma opt;
lzma_stream strm = LZMA_STREAM_INIT;
int res;
lzma_lzma_preset(&opt, LZMA_OPTIONS);
opt.dict_size = block_size;
res = lzma_alone_encoder(&strm, &opt);
if(res != LZMA_OK) {
lzma_end(&strm);
goto failed;
}
strm.next_out = dest;
strm.avail_out = block_size;
strm.next_in = src;
strm.avail_in = size;
res = lzma_code(&strm, LZMA_FINISH);
lzma_end(&strm);
if(res == LZMA_STREAM_END) {
/*
* Fill in the 8 byte little endian uncompressed size field in
* the LZMA header. 8 bytes is excessively large for squashfs
* but this is the standard LZMA header and which is expected by
* the kernel code
*/
d[LZMA_PROPS_SIZE] = size & 255;
d[LZMA_PROPS_SIZE + 1] = (size >> 8) & 255;
d[LZMA_PROPS_SIZE + 2] = (size >> 16) & 255;
d[LZMA_PROPS_SIZE + 3] = (size >> 24) & 255;
d[LZMA_PROPS_SIZE + 4] = 0;
d[LZMA_PROPS_SIZE + 5] = 0;
d[LZMA_PROPS_SIZE + 6] = 0;
d[LZMA_PROPS_SIZE + 7] = 0;
return (int) strm.total_out;
}
if(res == LZMA_OK)
/*
* Output buffer overflow. Return out of buffer space
*/
return 0;
failed:
/*
* All other errors return failure, with the compressor
* specific error code in *error
*/
*error = res;
return -1;
}
static int lzma_uncompress(void *dest, void *src, int size, int outsize,
int *error)
{
lzma_stream strm = LZMA_STREAM_INIT;
int uncompressed_size = 0, res;
unsigned char lzma_header[LZMA_HEADER_SIZE];
res = lzma_alone_decoder(&strm, MEMLIMIT);
if(res != LZMA_OK) {
lzma_end(&strm);
goto failed;
}
memcpy(lzma_header, src, LZMA_HEADER_SIZE);
uncompressed_size = lzma_header[LZMA_PROPS_SIZE] |
(lzma_header[LZMA_PROPS_SIZE + 1] << 8) |
(lzma_header[LZMA_PROPS_SIZE + 2] << 16) |
(lzma_header[LZMA_PROPS_SIZE + 3] << 24);
if(uncompressed_size > outsize) {
res = 0;
goto failed;
}
memset(lzma_header + LZMA_PROPS_SIZE, 255, LZMA_UNCOMP_SIZE);
strm.next_out = dest;
strm.avail_out = outsize;
strm.next_in = lzma_header;
strm.avail_in = LZMA_HEADER_SIZE;
res = lzma_code(&strm, LZMA_RUN);
if(res != LZMA_OK || strm.avail_in != 0) {
lzma_end(&strm);
goto failed;
}
strm.next_in = src + LZMA_HEADER_SIZE;
strm.avail_in = size - LZMA_HEADER_SIZE;
res = lzma_code(&strm, LZMA_FINISH);
lzma_end(&strm);
if(res == LZMA_STREAM_END || (res == LZMA_OK &&
strm.total_out >= uncompressed_size && strm.avail_in == 0))
return uncompressed_size;
failed:
*error = res;
return -1;
}
static void lzma_usage(FILE *stream)
{
fprintf(stream, "\t (no options) (deprecated - no kernel support)\n");
}
struct compressor lzma_comp_ops = {
.init = NULL,
.compress = lzma_compress,
.uncompress = lzma_uncompress,
.options = NULL,
.usage = lzma_usage,
.id = LZMA_COMPRESSION,
.name = "lzma",
.supported = 1
};
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