diff options
Diffstat (limited to 'squashfs-tools/lzo_wrapper.c')
-rw-r--r-- | squashfs-tools/lzo_wrapper.c | 450 |
1 files changed, 450 insertions, 0 deletions
diff --git a/squashfs-tools/lzo_wrapper.c b/squashfs-tools/lzo_wrapper.c new file mode 100644 index 0000000..147c8ef --- /dev/null +++ b/squashfs-tools/lzo_wrapper.c @@ -0,0 +1,450 @@ +/* + * Copyright (c) 2013, 2014, 2021. 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. + * + * lzo_wrapper.c + * + * Support for LZO compression http://www.oberhumer.com/opensource/lzo + */ + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <lzo/lzoconf.h> +#include <lzo/lzo1x.h> + +#include "squashfs_fs.h" +#include "lzo_wrapper.h" +#include "compressor.h" + +static struct lzo_algorithm lzo[] = { + { "lzo1x_1", LZO1X_1_MEM_COMPRESS, lzo1x_1_compress }, + { "lzo1x_1_11", LZO1X_1_11_MEM_COMPRESS, lzo1x_1_11_compress }, + { "lzo1x_1_12", LZO1X_1_12_MEM_COMPRESS, lzo1x_1_12_compress }, + { "lzo1x_1_15", LZO1X_1_15_MEM_COMPRESS, lzo1x_1_15_compress }, + { "lzo1x_999", LZO1X_999_MEM_COMPRESS, lzo1x_999_wrapper }, + { NULL, 0, NULL } +}; + +/* default LZO compression algorithm and compression level */ +static int algorithm = SQUASHFS_LZO1X_999; +static int compression_level = SQUASHFS_LZO1X_999_COMP_DEFAULT; + +/* user specified compression level */ +static int user_comp_level = -1; + + +/* + * This function is called by the options parsing code in mksquashfs.c + * to parse any -X compressor option. + * + * This function returns: + * >=0 (number of additional args parsed) on success + * -1 if the option was unrecognised, or + * -2 if the option was recognised, but otherwise bad in + * some way (e.g. invalid parameter) + * + * Note: this function sets internal compressor state, but does not + * pass back the results of the parsing other than success/failure. + * The lzo_dump_options() function is called later to get the options in + * a format suitable for writing to the filesystem. + */ +static int lzo_options(char *argv[], int argc) +{ + int i; + + if(strcmp(argv[0], "-Xalgorithm") == 0) { + if(argc < 2) { + fprintf(stderr, "lzo: -Xalgorithm missing algorithm\n"); + fprintf(stderr, "lzo: -Xalgorithm <algorithm>\n"); + goto failed2; + } + + for(i = 0; lzo[i].name; i++) { + if(strcmp(argv[1], lzo[i].name) == 0) { + algorithm = i; + return 1; + } + } + + fprintf(stderr, "lzo: -Xalgorithm unrecognised algorithm\n"); + goto failed2; + } else if(strcmp(argv[0], "-Xcompression-level") == 0) { + if(argc < 2) { + fprintf(stderr, "lzo: -Xcompression-level missing " + "compression level\n"); + fprintf(stderr, "lzo: -Xcompression-level it " + "should be 1 >= n <= 9\n"); + goto failed; + } + + user_comp_level = atoi(argv[1]); + if(user_comp_level < 1 || user_comp_level > 9) { + fprintf(stderr, "lzo: -Xcompression-level invalid, it " + "should be 1 >= n <= 9\n"); + goto failed; + } + + return 1; + } + + return -1; + +failed: + return -2; + +failed2: + fprintf(stderr, "lzo: compression algorithm should be one of:\n"); + for(i = 0; lzo[i].name; i++) + fprintf(stderr, "\t%s\n", lzo[i].name); + return -2; +} + + +/* + * This function is called after all options have been parsed. + * It is used to do post-processing on the compressor options using + * values that were not expected to be known at option parse time. + * + * In this case the LZO algorithm may not be known until after the + * compression level has been set (-Xalgorithm used after -Xcompression-level) + * + * This function returns 0 on successful post processing, or + * -1 on error + */ +static int lzo_options_post(int block_size) +{ + /* + * Use of compression level only makes sense for + * LZO1X_999 algorithm + */ + if(user_comp_level != -1) { + if(algorithm != SQUASHFS_LZO1X_999) { + fprintf(stderr, "lzo: -Xcompression-level not " + "supported by selected %s algorithm\n", + lzo[algorithm].name); + fprintf(stderr, "lzo: -Xcompression-level is only " + "applicable for the lzo1x_999 algorithm\n"); + goto failed; + } + compression_level = user_comp_level; + } + + return 0; + +failed: + return -1; +} + + +/* + * This function is called by mksquashfs to dump the parsed + * compressor options in a format suitable for writing to the + * compressor options field in the filesystem (stored immediately + * after the superblock). + * + * This function returns a pointer to the compression options structure + * to be stored (and the size), or NULL if there are no compression + * options + * + */ +static void *lzo_dump_options(int block_size, int *size) +{ + static struct lzo_comp_opts comp_opts; + + /* + * If default compression options of SQUASHFS_LZO1X_999 and + * compression level of SQUASHFS_LZO1X_999_COMP_DEFAULT then + * don't store a compression options structure (this is compatible + * with the legacy implementation of LZO for Squashfs) + */ + if(algorithm == SQUASHFS_LZO1X_999 && + compression_level == SQUASHFS_LZO1X_999_COMP_DEFAULT) + return NULL; + + comp_opts.algorithm = algorithm; + comp_opts.compression_level = algorithm == SQUASHFS_LZO1X_999 ? + compression_level : 0; + + SQUASHFS_INSWAP_COMP_OPTS(&comp_opts); + + *size = sizeof(comp_opts); + return &comp_opts; +} + + +/* + * This function is a helper specifically for the append mode of + * mksquashfs. Its purpose is to set the internal compressor state + * to the stored compressor options in the passed compressor options + * structure. + * + * In effect this function sets up the compressor options + * to the same state they were when the filesystem was originally + * generated, this is to ensure on appending, the compressor uses + * the same compression options that were used to generate the + * original filesystem. + * + * Note, even if there are no compressor options, this function is still + * called with an empty compressor structure (size == 0), to explicitly + * set the default options, this is to ensure any user supplied + * -X options on the appending mksquashfs command line are over-ridden + * + * This function returns 0 on sucessful extraction of options, and + * -1 on error + */ +static int lzo_extract_options(int block_size, void *buffer, int size) +{ + struct lzo_comp_opts *comp_opts = buffer; + + if(size == 0) { + /* Set default values */ + algorithm = SQUASHFS_LZO1X_999; + compression_level = SQUASHFS_LZO1X_999_COMP_DEFAULT; + return 0; + } + + /* we expect a comp_opts structure of sufficient size to be present */ + if(size < sizeof(*comp_opts)) + goto failed; + + SQUASHFS_INSWAP_COMP_OPTS(comp_opts); + + /* Check comp_opts structure for correctness */ + switch(comp_opts->algorithm) { + case SQUASHFS_LZO1X_1: + case SQUASHFS_LZO1X_1_11: + case SQUASHFS_LZO1X_1_12: + case SQUASHFS_LZO1X_1_15: + if(comp_opts->compression_level != 0) { + fprintf(stderr, "lzo: bad compression level in " + "compression options structure\n"); + goto failed; + } + break; + case SQUASHFS_LZO1X_999: + if(comp_opts->compression_level < 1 || + comp_opts->compression_level > 9) { + fprintf(stderr, "lzo: bad compression level in " + "compression options structure\n"); + goto failed; + } + compression_level = comp_opts->compression_level; + break; + default: + fprintf(stderr, "lzo: bad algorithm in compression options " + "structure\n"); + goto failed; + } + + algorithm = comp_opts->algorithm; + + return 0; + +failed: + fprintf(stderr, "lzo: error reading stored compressor options from " + "filesystem!\n"); + + return -1; +} + + +static void lzo_display_options(void *buffer, int size) +{ + struct lzo_comp_opts *comp_opts = buffer; + + /* we expect a comp_opts structure of sufficient size to be present */ + if(size < sizeof(*comp_opts)) + goto failed; + + SQUASHFS_INSWAP_COMP_OPTS(comp_opts); + + /* Check comp_opts structure for correctness */ + switch(comp_opts->algorithm) { + case SQUASHFS_LZO1X_1: + case SQUASHFS_LZO1X_1_11: + case SQUASHFS_LZO1X_1_12: + case SQUASHFS_LZO1X_1_15: + printf("\talgorithm %s\n", lzo[comp_opts->algorithm].name); + break; + case SQUASHFS_LZO1X_999: + if(comp_opts->compression_level < 1 || + comp_opts->compression_level > 9) { + fprintf(stderr, "lzo: bad compression level in " + "compression options structure\n"); + goto failed; + } + printf("\talgorithm %s\n", lzo[comp_opts->algorithm].name); + printf("\tcompression level %d\n", + comp_opts->compression_level); + break; + default: + fprintf(stderr, "lzo: bad algorithm in compression options " + "structure\n"); + goto failed; + } + + return; + +failed: + fprintf(stderr, "lzo: error reading stored compressor options from " + "filesystem!\n"); +} + + +/* + * This function is called by mksquashfs to initialise the + * compressor, before compress() is called. + * + * This function returns 0 on success, and + * -1 on error + */ +static int squashfs_lzo_init(void **strm, int block_size, int datablock) +{ + struct lzo_stream *stream; + + stream = *strm = malloc(sizeof(struct lzo_stream)); + if(stream == NULL) + goto failed; + + stream->workspace = malloc(lzo[algorithm].size); + if(stream->workspace == NULL) + goto failed2; + + stream->buffer = malloc(LZO_MAX_EXPANSION(block_size)); + if(stream->buffer != NULL) + return 0; + + free(stream->workspace); +failed2: + free(stream); +failed: + return -1; +} + + +static int lzo_compress(void *strm, void *dest, void *src, int size, + int block_size, int *error) +{ + int res; + lzo_uint compsize, orig_size = size; + struct lzo_stream *stream = strm; + + res = lzo[algorithm].compress(src, size, stream->buffer, &compsize, + stream->workspace); + if(res != LZO_E_OK) + goto failed; + + /* Successful compression, however, we need to check that + * the compressed size is not larger than the available + * buffer space. Normally in other compressor APIs they take + * a destination buffer size, and overflows return an error. + * With LZO it lacks a destination size and so we must output + * to a temporary buffer large enough to accomodate any + * result, and explictly check here for overflow + */ + if(compsize > block_size) + return 0; + + res = lzo1x_optimize(stream->buffer, compsize, src, &orig_size, NULL); + + if (res != LZO_E_OK || orig_size != size) + goto failed; + + memcpy(dest, stream->buffer, compsize); + return compsize; + +failed: + /* fail, compressor specific error code returned in error */ + *error = res; + return -1; +} + + +static int lzo_uncompress(void *dest, void *src, int size, int outsize, + int *error) +{ + int res; + lzo_uint outlen = outsize; + + res = lzo1x_decompress_safe(src, size, dest, &outlen, NULL); + if(res != LZO_E_OK) { + *error = res; + return -1; + } + + return outlen; +} + + +static void lzo_usage(FILE *stream) +{ + int i; + + fprintf(stream, "\t -Xalgorithm <algorithm>\n"); + fprintf(stream, "\t\tWhere <algorithm> is one of:\n"); + + for(i = 0; lzo[i].name; i++) + fprintf(stream, "\t\t\t%s%s\n", lzo[i].name, + i == SQUASHFS_LZO1X_999 ? " (default)" : ""); + + fprintf(stream, "\t -Xcompression-level <compression-level>\n"); + fprintf(stream, "\t\t<compression-level> should be 1 .. 9 (default " + "%d)\n", SQUASHFS_LZO1X_999_COMP_DEFAULT); + fprintf(stream, "\t\tOnly applies to lzo1x_999 algorithm\n"); +} + + +/* + * Helper function for lzo1x_999 compression algorithm. + * All other lzo1x_xxx compressors do not take a compression level, + * so we need to wrap lzo1x_999 to pass the compression level which + * is applicable to it + */ +int lzo1x_999_wrapper(const lzo_bytep src, lzo_uint src_len, lzo_bytep dst, + lzo_uintp compsize, lzo_voidp workspace) +{ + return lzo1x_999_compress_level(src, src_len, dst, compsize, + workspace, NULL, 0, 0, compression_level); +} + + +static int option_args(char *option) +{ + if(strcmp(option, "-Xalgorithm") == 0 || + strcmp(option, "-Xcompression-level") == 0) + return 1; + + return 0; +} + + +struct compressor lzo_comp_ops = { + .init = squashfs_lzo_init, + .compress = lzo_compress, + .uncompress = lzo_uncompress, + .options = lzo_options, + .options_post = lzo_options_post, + .dump_options = lzo_dump_options, + .extract_options = lzo_extract_options, + .display_options = lzo_display_options, + .usage = lzo_usage, + .option_args = option_args, + .id = LZO_COMPRESSION, + .name = "lzo", + .supported = 1 +}; |