summaryrefslogtreecommitdiff
path: root/sys/ntfs/ntfs_compr.c
blob: 98b1fbb6c028bd961e0d232d358c851046ff9d1d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
/*	$OpenBSD: ntfs_compr.c,v 1.2 2003/05/20 03:23:11 mickey Exp $	*/
/*	$NetBSD: ntfs_compr.c,v 1.1 2002/12/23 17:38:31 jdolecek Exp $	*/

/*-
 * Copyright (c) 1998, 1999 Semen Ustimenko
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	Id: ntfs_compr.c,v 1.4 1999/05/12 09:42:54 semenu Exp
 */

#include <sys/cdefs.h>
#ifdef __KERNEL_RCSID
__KERNEL_RCSID(0, "$NetBSD: ntfs_compr.c,v 1.1 2002/12/23 17:38:31 jdolecek Exp $");
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/file.h>
#include <sys/malloc.h>
#ifdef __FreeBSD__
#include <machine/clock.h>
#endif

#include <miscfs/specfs/specdev.h>

#if defined(__FreeBSD__) || defined(__NetBSD__)
#include <fs/ntfs/ntfs.h>
#include <fs/ntfs/ntfs_compr.h>
#else
#include <ntfs/ntfs.h>
#include <ntfs/ntfs_compr.h>
#endif

#define GET_UINT16(addr)	(*((u_int16_t *)(addr)))

int
ntfs_uncompblock(
	u_int8_t * buf,
	u_int8_t * cbuf)
{
	u_int32_t       ctag;
	int             len, dshift, lmask;
	int             blen, boff;
	int             i, j;
	int             pos, cpos;

	len = GET_UINT16(cbuf) & 0xFFF;
	dprintf(("ntfs_uncompblock: block length: %d + 3, 0x%x,0x%04x\n",
	    len, len, GET_UINT16(cbuf)));

	if (!(GET_UINT16(cbuf) & 0x8000)) {
		if ((len + 1) != NTFS_COMPBLOCK_SIZE) {
			dprintf(("ntfs_uncompblock: len: %x instead of %d\n",
			    len, 0xfff));
		}
		memcpy(buf, cbuf + 2, len + 1);
		bzero(buf + len + 1, NTFS_COMPBLOCK_SIZE - 1 - len);
		return len + 3;
	}
	cpos = 2;
	pos = 0;
	while ((cpos < len + 3) && (pos < NTFS_COMPBLOCK_SIZE)) {
		ctag = cbuf[cpos++];
		for (i = 0; (i < 8) && (pos < NTFS_COMPBLOCK_SIZE); i++) {
			if (ctag & 1) {
				for (j = pos - 1, lmask = 0xFFF, dshift = 12;
				     j >= 0x10; j >>= 1) {
					dshift--;
					lmask >>= 1;
				}
				boff = -1 - (GET_UINT16(cbuf + cpos) >> dshift);
				blen = 3 + (GET_UINT16(cbuf + cpos) & lmask);
				for (j = 0; (j < blen) && (pos < NTFS_COMPBLOCK_SIZE); j++) {
					buf[pos] = buf[pos + boff];
					pos++;
				}
				cpos += 2;
			} else {
				buf[pos++] = cbuf[cpos++];
			}
			ctag >>= 1;
		}
	}
	return len + 3;
}

int
ntfs_uncompunit(
	struct ntfsmount * ntmp,
	u_int8_t * uup,
	u_int8_t * cup)
{
	int             i;
	int             off = 0;
	int             new;

	for (i = 0; i * NTFS_COMPBLOCK_SIZE < ntfs_cntob(NTFS_COMPUNIT_CL); i++) {
		new = ntfs_uncompblock(uup + i * NTFS_COMPBLOCK_SIZE, cup + off);
		if (new == 0)
			return (EINVAL);
		off += new;
	}
	return (0);
}