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annotate xen/common/unlzo.c @ 22848:6341fe0f4e5a

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Added tag 4.1.0-rc2 for changeset 9dca60d88c63
author Keir Fraser <keir@xen.org>
date Tue Jan 25 14:06:55 2011 +0000 (2011-01-25)
parents d8333666361d
children
rev   line source
keir@21663 1 /*
keir@21663 2 * LZO decompressor for the Linux kernel. Code borrowed from the lzo
keir@21663 3 * implementation by Markus Franz Xaver Johannes Oberhumer.
keir@21663 4 *
keir@21663 5 * Linux kernel adaptation:
keir@21663 6 * Copyright (C) 2009
keir@21663 7 * Albin Tonnerre, Free Electrons <albin.tonnerre@free-electrons.com>
keir@21663 8 *
keir@21663 9 * Original code:
keir@21663 10 * Copyright (C) 1996-2005 Markus Franz Xaver Johannes Oberhumer
keir@21663 11 * All Rights Reserved.
keir@21663 12 *
keir@21663 13 * lzop and the LZO library are free software; you can redistribute them
keir@21663 14 * and/or modify them under the terms of the GNU General Public License as
keir@21663 15 * published by the Free Software Foundation; either version 2 of
keir@21663 16 * the License, or (at your option) any later version.
keir@21663 17 *
keir@21663 18 * This program is distributed in the hope that it will be useful,
keir@21663 19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
keir@21663 20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
keir@21663 21 * GNU General Public License for more details.
keir@21663 22 *
keir@21663 23 * You should have received a copy of the GNU General Public License
keir@21663 24 * along with this program; see the file COPYING.
keir@21663 25 * If not, write to the Free Software Foundation, Inc.,
keir@21663 26 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
keir@21663 27 *
keir@21663 28 * Markus F.X.J. Oberhumer
keir@21663 29 * <markus@oberhumer.com>
keir@21663 30 * http://www.oberhumer.com/opensource/lzop/
keir@21663 31 */
keir@21663 32
keir@21663 33 #include "decompress.h"
keir@21663 34 #include <xen/lzo.h>
keir@21663 35 #include <asm/byteorder.h>
keir@21663 36
keir@21663 37 #if 1 /* ndef CONFIG_??? */
keir@21663 38 static inline u16 INIT get_unaligned_be16(void *p)
keir@21663 39 {
keir@21663 40 return be16_to_cpup(p);
keir@21663 41 }
keir@21663 42
keir@21663 43 static inline u32 INIT get_unaligned_be32(void *p)
keir@21663 44 {
keir@21663 45 return be32_to_cpup(p);
keir@21663 46 }
keir@21663 47 #else
keir@21663 48 #include <asm/unaligned.h>
keir@21663 49
keir@21663 50 static inline u16 INIT get_unaligned_be16(void *p)
keir@21663 51 {
keir@21663 52 return be16_to_cpu(__get_unaligned(p, 2));
keir@21663 53 }
keir@21663 54
keir@21663 55 static inline u32 INIT get_unaligned_be32(void *p)
keir@21663 56 {
keir@21663 57 return be32_to_cpu(__get_unaligned(p, 4));
keir@21663 58 }
keir@21663 59 #endif
keir@21663 60
keir@21663 61 static const unsigned char lzop_magic[] = {
keir@21663 62 0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a };
keir@21663 63
keir@21663 64 #define LZO_BLOCK_SIZE (256*1024l)
keir@21663 65 #define HEADER_HAS_FILTER 0x00000800L
keir@21663 66
keir@21663 67 static int INIT parse_header(u8 *input, u8 *skip)
keir@21663 68 {
keir@21663 69 int l;
keir@21663 70 u8 *parse = input;
keir@21663 71 u8 level = 0;
keir@21663 72 u16 version;
keir@21663 73
keir@21663 74 /* read magic: 9 first bits */
keir@21663 75 for (l = 0; l < 9; l++) {
keir@21663 76 if (*parse++ != lzop_magic[l])
keir@21663 77 return 0;
keir@21663 78 }
keir@21663 79 /* get version (2bytes), skip library version (2),
keir@21663 80 * 'need to be extracted' version (2) and
keir@21663 81 * method (1) */
keir@21663 82 version = get_unaligned_be16(parse);
keir@21663 83 parse += 7;
keir@21663 84 if (version >= 0x0940)
keir@21663 85 level = *parse++;
keir@21663 86 if (get_unaligned_be32(parse) & HEADER_HAS_FILTER)
keir@21663 87 parse += 8; /* flags + filter info */
keir@21663 88 else
keir@21663 89 parse += 4; /* flags */
keir@21663 90
keir@21663 91 /* skip mode and mtime_low */
keir@21663 92 parse += 8;
keir@21663 93 if (version >= 0x0940)
keir@21663 94 parse += 4; /* skip mtime_high */
keir@21663 95
keir@21663 96 l = *parse++;
keir@21663 97 /* don't care about the file name, and skip checksum */
keir@21663 98 parse += l + 4;
keir@21663 99
keir@21663 100 *skip = parse - input;
keir@21663 101 return 1;
keir@21663 102 }
keir@21663 103
keir@21663 104 STATIC int INIT unlzo(u8 *input, unsigned int in_len,
keir@21663 105 int (*fill) (void *, unsigned int),
keir@21663 106 int (*flush) (void *, unsigned int),
keir@21663 107 u8 *output, unsigned int *posp,
keir@21663 108 void (*error_fn) (const char *x))
keir@21663 109 {
keir@21663 110 u8 skip = 0, r = 0;
keir@21663 111 u32 src_len, dst_len;
keir@21663 112 size_t tmp;
keir@21663 113 u8 *in_buf, *in_buf_save, *out_buf;
keir@21663 114 int ret = -1;
keir@21663 115
keir@21663 116 set_error_fn(error_fn);
keir@21663 117
keir@21663 118 if (output) {
keir@21663 119 out_buf = output;
keir@21663 120 } else if (!flush) {
keir@21663 121 error("NULL output pointer and no flush function provided");
keir@21663 122 goto exit;
keir@21663 123 } else {
keir@21663 124 out_buf = malloc(LZO_BLOCK_SIZE);
keir@21663 125 if (!out_buf) {
keir@21663 126 error("Could not allocate output buffer");
keir@21663 127 goto exit;
keir@21663 128 }
keir@21663 129 }
keir@21663 130
keir@21663 131 if (input && fill) {
keir@21663 132 error("Both input pointer and fill function provided, don't know what to do");
keir@21663 133 goto exit_1;
keir@21663 134 } else if (input) {
keir@21663 135 in_buf = input;
keir@21663 136 } else if (!fill || !posp) {
keir@21663 137 error("NULL input pointer and missing position pointer or fill function");
keir@21663 138 goto exit_1;
keir@21663 139 } else {
keir@21663 140 in_buf = malloc(lzo1x_worst_compress(LZO_BLOCK_SIZE));
keir@21663 141 if (!in_buf) {
keir@21663 142 error("Could not allocate input buffer");
keir@21663 143 goto exit_1;
keir@21663 144 }
keir@21663 145 }
keir@21663 146 in_buf_save = in_buf;
keir@21663 147
keir@21663 148 if (posp)
keir@21663 149 *posp = 0;
keir@21663 150
keir@21663 151 if (fill)
keir@21663 152 fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE));
keir@21663 153
keir@21663 154 if (!parse_header(input, &skip)) {
keir@21663 155 error("invalid header");
keir@21663 156 goto exit_2;
keir@21663 157 }
keir@21663 158 in_buf += skip;
keir@21663 159
keir@21663 160 if (posp)
keir@21663 161 *posp = skip;
keir@21663 162
keir@21663 163 for (;;) {
keir@21663 164 /* read uncompressed block size */
keir@21663 165 dst_len = get_unaligned_be32(in_buf);
keir@21663 166 in_buf += 4;
keir@21663 167
keir@21663 168 /* exit if last block */
keir@21663 169 if (dst_len == 0) {
keir@21663 170 if (posp)
keir@21663 171 *posp += 4;
keir@21663 172 break;
keir@21663 173 }
keir@21663 174
keir@21663 175 if (dst_len > LZO_BLOCK_SIZE) {
keir@21663 176 error("dest len longer than block size");
keir@21663 177 goto exit_2;
keir@21663 178 }
keir@21663 179
keir@21663 180 /* read compressed block size, and skip block checksum info */
keir@21663 181 src_len = get_unaligned_be32(in_buf);
keir@21663 182 in_buf += 8;
keir@21663 183
keir@21663 184 if (src_len <= 0 || src_len > dst_len) {
keir@21663 185 error("file corrupted");
keir@21663 186 goto exit_2;
keir@21663 187 }
keir@21663 188
keir@21663 189 /* decompress */
keir@21663 190 tmp = dst_len;
keir@21663 191
keir@21663 192 /* When the input data is not compressed at all,
keir@21663 193 * lzo1x_decompress_safe will fail, so call memcpy()
keir@21663 194 * instead */
keir@21663 195 if (unlikely(dst_len == src_len))
keir@21663 196 memcpy(out_buf, in_buf, src_len);
keir@21663 197 else {
keir@21663 198 r = lzo1x_decompress_safe(in_buf, src_len,
keir@21663 199 out_buf, &tmp);
keir@21663 200
keir@21663 201 if (r != LZO_E_OK || dst_len != tmp) {
keir@21663 202 error("Compressed data violation");
keir@21663 203 goto exit_2;
keir@21663 204 }
keir@21663 205 }
keir@21663 206
keir@21663 207 if (flush)
keir@21663 208 flush(out_buf, dst_len);
keir@21663 209 if (output)
keir@21663 210 out_buf += dst_len;
keir@21663 211 if (posp)
keir@21663 212 *posp += src_len + 12;
keir@21663 213 if (fill) {
keir@21663 214 in_buf = in_buf_save;
keir@21663 215 fill(in_buf, lzo1x_worst_compress(LZO_BLOCK_SIZE));
keir@21663 216 } else
keir@21663 217 in_buf += src_len;
keir@21663 218 }
keir@21663 219
keir@21663 220 ret = 0;
keir@21663 221 exit_2:
keir@21663 222 if (!input)
keir@21663 223 free(in_buf);
keir@21663 224 exit_1:
keir@21663 225 if (!output)
keir@21663 226 free(out_buf);
keir@21663 227 exit:
keir@21663 228 return ret;
keir@21663 229 }