1 /* 2 * Copyright (c) 2009, 2010, 2013 3 * Phillip Lougher <phillip (at) squashfs.org.uk> 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License 7 * as published by the Free Software Foundation; either version 2, 8 * or (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 18 * 19 * lzma_wrapper.c 20 * 21 * Support for LZMA1 compression using LZMA SDK (4.65 used in 22 * development, other versions may work) http://www.7-zip.org/sdk.html 23 */ 24 25 #include <LzmaLib.h> 26 27 #include "squashfs_fs.h" 28 #include "compressor.h" 29 30 #define LZMA_HEADER_SIZE (LZMA_PROPS_SIZE + 8) 31 32 static int lzma_compress(void *strm, void *dest, void *src, int size, int block_size, 33 int *error) 34 { 35 unsigned char *d = dest; 36 size_t props_size = LZMA_PROPS_SIZE, 37 outlen = block_size - LZMA_HEADER_SIZE; 38 int res; 39 40 res = LzmaCompress(dest + LZMA_HEADER_SIZE, &outlen, src, size, dest, 41 &props_size, 5, block_size, 3, 0, 2, 32, 1); 42 43 if(res == SZ_ERROR_OUTPUT_EOF) { 44 /* 45 * Output buffer overflow. Return out of buffer space error 46 */ 47 return 0; 48 } 49 50 if(res != SZ_OK) { 51 /* 52 * All other errors return failure, with the compressor 53 * specific error code in *error 54 */ 55 *error = res; 56 return -1; 57 } 58 59 /* 60 * Fill in the 8 byte little endian uncompressed size field in the 61 * LZMA header. 8 bytes is excessively large for squashfs but 62 * this is the standard LZMA header and which is expected by the kernel 63 * code 64 */ 65 d[LZMA_PROPS_SIZE] = size & 255; 66 d[LZMA_PROPS_SIZE + 1] = (size >> 8) & 255; 67 d[LZMA_PROPS_SIZE + 2] = (size >> 16) & 255; 68 d[LZMA_PROPS_SIZE + 3] = (size >> 24) & 255; 69 d[LZMA_PROPS_SIZE + 4] = 0; 70 d[LZMA_PROPS_SIZE + 5] = 0; 71 d[LZMA_PROPS_SIZE + 6] = 0; 72 d[LZMA_PROPS_SIZE + 7] = 0; 73 74 /* 75 * Success, return the compressed size. Outlen returned by the LZMA 76 * compressor does not include the LZMA header space 77 */ 78 return outlen + LZMA_HEADER_SIZE; 79 } 80 81 82 static int lzma_uncompress(void *dest, void *src, int size, int outsize, 83 int *error) 84 { 85 unsigned char *s = src; 86 size_t outlen, inlen = size - LZMA_HEADER_SIZE; 87 int res; 88 89 outlen = s[LZMA_PROPS_SIZE] | 90 (s[LZMA_PROPS_SIZE + 1] << 8) | 91 (s[LZMA_PROPS_SIZE + 2] << 16) | 92 (s[LZMA_PROPS_SIZE + 3] << 24); 93 94 if(outlen > outsize) { 95 *error = 0; 96 return -1; 97 } 98 99 res = LzmaUncompress(dest, &outlen, src + LZMA_HEADER_SIZE, &inlen, src, 100 LZMA_PROPS_SIZE); 101 102 if(res == SZ_OK) 103 return outlen; 104 else { 105 *error = res; 106 return -1; 107 } 108 } 109 110 111 struct compressor lzma_comp_ops = { 112 .init = NULL, 113 .compress = lzma_compress, 114 .uncompress = lzma_uncompress, 115 .options = NULL, 116 .usage = NULL, 117 .id = LZMA_COMPRESSION, 118 .name = "lzma", 119 .supported = 1 120 }; 121 122
