diff options
Diffstat (limited to 'squashfs-tools/lzma_wrapper.c')
| -rw-r--r-- | squashfs-tools/lzma_wrapper.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/squashfs-tools/lzma_wrapper.c b/squashfs-tools/lzma_wrapper.c new file mode 100644 index 0000000..d06cacc --- /dev/null +++ b/squashfs-tools/lzma_wrapper.c @@ -0,0 +1,127 @@ +/* + * Copyright (c) 2009, 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_wrapper.c + * + * Support for LZMA1 compression using LZMA SDK (4.65 used in + * development, other versions may work) http://www.7-zip.org/sdk.html + */ + +#include <LzmaLib.h> + +#include "squashfs_fs.h" +#include "compressor.h" + +#define LZMA_HEADER_SIZE (LZMA_PROPS_SIZE + 8) + +static int lzma_compress(void *strm, void *dest, void *src, int size, int block_size, + int *error) +{ + unsigned char *d = dest; + size_t props_size = LZMA_PROPS_SIZE, + outlen = block_size - LZMA_HEADER_SIZE; + int res; + + res = LzmaCompress(dest + LZMA_HEADER_SIZE, &outlen, src, size, dest, + &props_size, 5, block_size, 3, 0, 2, 32, 1); + + if(res == SZ_ERROR_OUTPUT_EOF) { + /* + * Output buffer overflow. Return out of buffer space error + */ + return 0; + } + + if(res != SZ_OK) { + /* + * All other errors return failure, with the compressor + * specific error code in *error + */ + *error = res; + return -1; + } + + /* + * 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; + + /* + * Success, return the compressed size. Outlen returned by the LZMA + * compressor does not include the LZMA header space + */ + return outlen + LZMA_HEADER_SIZE; +} + + +static int lzma_uncompress(void *dest, void *src, int size, int outsize, + int *error) +{ + unsigned char *s = src; + size_t outlen, inlen = size - LZMA_HEADER_SIZE; + int res; + + outlen = s[LZMA_PROPS_SIZE] | + (s[LZMA_PROPS_SIZE + 1] << 8) | + (s[LZMA_PROPS_SIZE + 2] << 16) | + (s[LZMA_PROPS_SIZE + 3] << 24); + + if(outlen > outsize) { + *error = 0; + return -1; + } + + res = LzmaUncompress(dest, &outlen, src + LZMA_HEADER_SIZE, &inlen, src, + LZMA_PROPS_SIZE); + + if(res == SZ_OK) + return outlen; + else { + *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 +}; + |