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Jorgen Lundman4d3c95f2012-07-19 20:48:25 +00001/*
2 * GRUB -- GRand Unified Bootloader
3 * Copyright (C) 1999,2000,2001,2002,2003,2004 Free Software Foundation, Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (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, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19/*
20 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
21 * Use is subject to license terms.
22 */
23
24#include <common.h>
25#include <malloc.h>
26#include <linux/stat.h>
27#include <linux/time.h>
28#include <linux/ctype.h>
29#include <asm/byteorder.h>
30#include "zfs_common.h"
31
32#include <zfs/zfs.h>
33#include <zfs/zio.h>
34#include <zfs/dnode.h>
35#include <zfs/uberblock_impl.h>
36#include <zfs/vdev_impl.h>
37#include <zfs/zio_checksum.h>
38#include <zfs/zap_impl.h>
39#include <zfs/zap_leaf.h>
40#include <zfs/zfs_znode.h>
41#include <zfs/dmu.h>
42#include <zfs/dmu_objset.h>
43#include <zfs/dsl_dir.h>
44#include <zfs/dsl_dataset.h>
45
46#define MATCH_BITS 6
47#define MATCH_MIN 3
48#define OFFSET_MASK ((1 << (16 - MATCH_BITS)) - 1)
49
50/*
51 * Decompression Entry - lzjb
52 */
53#ifndef NBBY
54#define NBBY 8
55#endif
56
57int
58lzjb_decompress(void *s_start, void *d_start, uint32_t s_len,
59 uint32_t d_len)
60{
61 uint8_t *src = s_start;
62 uint8_t *dst = d_start;
63 uint8_t *d_end = (uint8_t *) d_start + d_len;
64 uint8_t *s_end = (uint8_t *) s_start + s_len;
65 uint8_t *cpy, copymap = 0;
66 int copymask = 1 << (NBBY - 1);
67
68 while (dst < d_end && src < s_end) {
69 if ((copymask <<= 1) == (1 << NBBY)) {
70 copymask = 1;
71 copymap = *src++;
72 }
73 if (src >= s_end) {
74 printf("lzjb decompression failed\n");
75 return ZFS_ERR_BAD_FS;
76 }
77 if (copymap & copymask) {
78 int mlen = (src[0] >> (NBBY - MATCH_BITS)) + MATCH_MIN;
79 int offset = ((src[0] << NBBY) | src[1]) & OFFSET_MASK;
80 src += 2;
81 cpy = dst - offset;
82 if (src > s_end || cpy < (uint8_t *) d_start) {
83 printf("lzjb decompression failed\n");
84 return ZFS_ERR_BAD_FS;
85 }
86 while (--mlen >= 0 && dst < d_end)
87 *dst++ = *cpy++;
88 } else {
89 *dst++ = *src++;
90 }
91 }
92 if (dst < d_end) {
93 printf("lzjb decompression failed\n");
94 return ZFS_ERR_BAD_FS;
95 }
96 return ZFS_ERR_NONE;
97}