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| 1 | +/* |
| 2 | + * LZO decompressor for the Linux kernel. Code borrowed from the lzo |
| 3 | + * implementation by Markus Franz Xaver Johannes Oberhumer. |
| 4 | + * |
| 5 | + * Linux kernel adaptation: |
| 6 | + * Copyright (C) 2009 |
| 7 | + * Albin Tonnerre, Free Electrons <[email protected]> |
| 8 | + * |
| 9 | + * Original code: |
| 10 | + * Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer |
| 11 | + * All Rights Reserved. |
| 12 | + * |
| 13 | + * lzop and the LZO library are free software; you can redistribute them |
| 14 | + * and/or modify them under the terms of the GNU General Public License as |
| 15 | + * published by the Free Software Foundation; either version 2 of |
| 16 | + * the License, or (at your option) any later version. |
| 17 | + * |
| 18 | + * This program is distributed in the hope that it will be useful, |
| 19 | + * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 21 | + * GNU General Public License for more details. |
| 22 | + * |
| 23 | + * You should have received a copy of the GNU General Public License |
| 24 | + * along with this program; see the file COPYING. |
| 25 | + * If not, write to the Free Software Foundation, Inc., |
| 26 | + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 27 | + * |
| 28 | + * Markus F.X.J. Oberhumer |
| 29 | + |
| 30 | + * http://www.oberhumer.com/opensource/lzop/ |
| 31 | + */ |
| 32 | + |
| 33 | +#ifdef STATIC |
| 34 | +#include "lzo/lzo1x_decompress.c" |
| 35 | +#else |
| 36 | +#include <linux/slab.h> |
| 37 | +#include <linux/decompress/unlzo.h> |
| 38 | +#endif |
| 39 | + |
| 40 | +#include <linux/types.h> |
| 41 | +#include <linux/lzo.h> |
| 42 | +#include <linux/decompress/mm.h> |
| 43 | + |
| 44 | +#include <linux/compiler.h> |
| 45 | +#include <asm/unaligned.h> |
| 46 | + |
| 47 | +static const unsigned char lzop_magic[] = { |
| 48 | + 0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a }; |
| 49 | + |
| 50 | +#define LZO_BLOCK_SIZE (256*1024l) |
| 51 | +#define HEADER_HAS_FILTER 0x00000800L |
| 52 | + |
| 53 | +STATIC inline int INIT parse_header(u8 *input, u8 *skip) |
| 54 | +{ |
| 55 | + int l; |
| 56 | + u8 *parse = input; |
| 57 | + u8 level = 0; |
| 58 | + u16 version; |
| 59 | + |
| 60 | + /* read magic: 9 first bits */ |
| 61 | + for (l = 0; l < 9; l++) { |
| 62 | + if (*parse++ != lzop_magic[l]) |
| 63 | + return 0; |
| 64 | + } |
| 65 | + /* get version (2bytes), skip library version (2), |
| 66 | + * 'need to be extracted' version (2) and |
| 67 | + * method (1) */ |
| 68 | + version = get_unaligned_be16(parse); |
| 69 | + parse += 7; |
| 70 | + if (version >= 0x0940) |
| 71 | + level = *parse++; |
| 72 | + if (get_unaligned_be32(parse) & HEADER_HAS_FILTER) |
| 73 | + parse += 8; /* flags + filter info */ |
| 74 | + else |
| 75 | + parse += 4; /* flags */ |
| 76 | + |
| 77 | + /* skip mode and mtime_low */ |
| 78 | + parse += 8; |
| 79 | + if (version >= 0x0940) |
| 80 | + parse += 4; /* skip mtime_high */ |
| 81 | + |
| 82 | + l = *parse++; |
| 83 | + /* don't care about the file name, and skip checksum */ |
| 84 | + parse += l + 4; |
| 85 | + |
| 86 | + *skip = parse - input; |
| 87 | + return 1; |
| 88 | +} |
| 89 | + |
| 90 | +STATIC inline int INIT unlzo(u8 *input, int in_len, |
| 91 | + int (*fill) (void *, unsigned int), |
| 92 | + int (*flush) (void *, unsigned int), |
| 93 | + u8 *output, int *posp, |
| 94 | + void (*error_fn) (char *x)) |
| 95 | +{ |
| 96 | + u8 skip = 0, r = 0; |
| 97 | + u32 src_len, dst_len; |
| 98 | + size_t tmp; |
| 99 | + u8 *in_buf, *in_buf_save, *out_buf; |
| 100 | + int obytes_processed = 0; |
| 101 | + |
| 102 | + set_error_fn(error_fn); |
| 103 | + |
| 104 | + if (output) { |
| 105 | + out_buf = output; |
| 106 | + } else if (!flush) { |
| 107 | + error("NULL output pointer and no flush function provided"); |
| 108 | + goto exit; |
| 109 | + } else { |
| 110 | + out_buf = malloc(LZO_BLOCK_SIZE); |
| 111 | + if (!out_buf) { |
| 112 | + error("Could not allocate output buffer"); |
| 113 | + goto exit; |
| 114 | + } |
| 115 | + } |
| 116 | + |
| 117 | + if (input && fill) { |
| 118 | + error("Both input pointer and fill function provided, don't know what to do"); |
| 119 | + goto exit_1; |
| 120 | + } else if (input) { |
| 121 | + in_buf = input; |
| 122 | + } else if (!fill || !posp) { |
| 123 | + error("NULL input pointer and missing position pointer or fill function"); |
| 124 | + goto exit_1; |
| 125 | + } else { |
| 126 | + in_buf = malloc(lzo1x_worst_compress(LZO_BLOCK_SIZE)); |
| 127 | + if (!in_buf) { |
| 128 | + error("Could not allocate input buffer"); |
| 129 | + goto exit_1; |
| 130 | + } |
| 131 | + } |
| 132 | + in_buf_save = in_buf; |
| 133 | + |
| 134 | + if (posp) |
| 135 | + *posp = 0; |
| 136 | + |
| 137 | + if (fill) |
| 138 | + fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE)); |
| 139 | + |
| 140 | + if (!parse_header(input, &skip)) { |
| 141 | + error("invalid header"); |
| 142 | + goto exit_2; |
| 143 | + } |
| 144 | + in_buf += skip; |
| 145 | + |
| 146 | + if (posp) |
| 147 | + *posp = skip; |
| 148 | + |
| 149 | + for (;;) { |
| 150 | + /* read uncompressed block size */ |
| 151 | + dst_len = get_unaligned_be32(in_buf); |
| 152 | + in_buf += 4; |
| 153 | + |
| 154 | + /* exit if last block */ |
| 155 | + if (dst_len == 0) { |
| 156 | + if (posp) |
| 157 | + *posp += 4; |
| 158 | + break; |
| 159 | + } |
| 160 | + |
| 161 | + if (dst_len > LZO_BLOCK_SIZE) { |
| 162 | + error("dest len longer than block size"); |
| 163 | + goto exit_2; |
| 164 | + } |
| 165 | + |
| 166 | + /* read compressed block size, and skip block checksum info */ |
| 167 | + src_len = get_unaligned_be32(in_buf); |
| 168 | + in_buf += 8; |
| 169 | + |
| 170 | + if (src_len <= 0 || src_len > dst_len) { |
| 171 | + error("file corrupted"); |
| 172 | + goto exit_2; |
| 173 | + } |
| 174 | + |
| 175 | + /* decompress */ |
| 176 | + tmp = dst_len; |
| 177 | + r = lzo1x_decompress_safe((u8 *) in_buf, src_len, |
| 178 | + out_buf, &tmp); |
| 179 | + |
| 180 | + if (r != LZO_E_OK || dst_len != tmp) { |
| 181 | + error("Compressed data violation"); |
| 182 | + goto exit_2; |
| 183 | + } |
| 184 | + |
| 185 | + obytes_processed += dst_len; |
| 186 | + if (flush) |
| 187 | + flush(out_buf, dst_len); |
| 188 | + if (output) |
| 189 | + out_buf += dst_len; |
| 190 | + if (posp) |
| 191 | + *posp += src_len + 12; |
| 192 | + if (fill) { |
| 193 | + in_buf = in_buf_save; |
| 194 | + fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE)); |
| 195 | + } else |
| 196 | + in_buf += src_len; |
| 197 | + } |
| 198 | + |
| 199 | +exit_2: |
| 200 | + if (!input) |
| 201 | + free(in_buf); |
| 202 | +exit_1: |
| 203 | + if (!output) |
| 204 | + free(out_buf); |
| 205 | +exit: |
| 206 | + return obytes_processed; |
| 207 | +} |
| 208 | + |
| 209 | +#define decompress unlzo |
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