1// SPDX-License-Identifier: GPL-2.0+
2/*
3 *  GRUB  --  GRand Unified Bootloader
4 *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
5 */
6/*
7 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
8 * Use is subject to license terms.
9 */
10
11#include <common.h>
12#include <malloc.h>
13#include <linux/stat.h>
14#include <linux/time.h>
15#include <linux/ctype.h>
16#include <asm/byteorder.h>
17#include "zfs_common.h"
18
19#include <zfs/zfs.h>
20#include <zfs/zio.h>
21#include <zfs/dnode.h>
22#include <zfs/uberblock_impl.h>
23#include <zfs/vdev_impl.h>
24#include <zfs/zio_checksum.h>
25#include <zfs/zap_impl.h>
26#include <zfs/zap_leaf.h>
27#include <zfs/zfs_znode.h>
28#include <zfs/dmu.h>
29#include <zfs/dmu_objset.h>
30#include <zfs/dsl_dir.h>
31#include <zfs/dsl_dataset.h>
32
33#define	MATCH_BITS	6
34#define	MATCH_MIN	3
35#define	OFFSET_MASK	((1 << (16 - MATCH_BITS)) - 1)
36
37/*
38 * Decompression Entry - lzjb
39 */
40#ifndef	NBBY
41#define	NBBY	8
42#endif
43
44int
45lzjb_decompress(void *s_start, void *d_start, uint32_t s_len,
46				uint32_t d_len)
47{
48	uint8_t *src = s_start;
49	uint8_t *dst = d_start;
50	uint8_t *d_end = (uint8_t *) d_start + d_len;
51	uint8_t *s_end = (uint8_t *) s_start + s_len;
52	uint8_t *cpy, copymap = 0;
53	int copymask = 1 << (NBBY - 1);
54
55	while (dst < d_end && src < s_end) {
56		if ((copymask <<= 1) == (1 << NBBY)) {
57			copymask = 1;
58			copymap = *src++;
59		}
60		if (src >= s_end) {
61			printf("lzjb decompression failed\n");
62			return ZFS_ERR_BAD_FS;
63		}
64		if (copymap & copymask) {
65			int mlen = (src[0] >> (NBBY - MATCH_BITS)) + MATCH_MIN;
66			int offset = ((src[0] << NBBY) | src[1]) & OFFSET_MASK;
67			src += 2;
68			cpy = dst - offset;
69			if (src > s_end || cpy < (uint8_t *) d_start) {
70				printf("lzjb decompression failed\n");
71				return ZFS_ERR_BAD_FS;
72			}
73			while (--mlen >= 0 && dst < d_end)
74				*dst++ = *cpy++;
75		} else {
76			*dst++ = *src++;
77		}
78	}
79	if (dst < d_end) {
80		printf("lzjb decompression failed\n");
81		return ZFS_ERR_BAD_FS;
82	}
83	return ZFS_ERR_NONE;
84}
85