1 /* $NetBSD: ntfs_compr.c,v 1.3 2005/12/11 12:24:29 christos Exp $ */
2
3 /*-
4 * Copyright (c) 1998, 1999 Semen Ustimenko
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * Id: ntfs_compr.c,v 1.4 1999/05/12 09:42:54 semenu Exp
29 */
30
31 #include <sys/cdefs.h>
32 __KERNEL_RCSID(0, "$NetBSD: ntfs_compr.c,v 1.3 2005/12/11 12:24:29 christos Exp $");
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/namei.h>
37 #include <sys/proc.h>
38 #include <sys/kernel.h>
39 #include <sys/vnode.h>
40 #include <sys/mount.h>
41 #include <sys/buf.h>
42 #include <sys/file.h>
43 #include <sys/malloc.h>
44 #ifdef __FreeBSD__
45 #include <machine/clock.h>
46 #endif
47
48 #include <miscfs/specfs/specdev.h>
49
50 #include <fs/ntfs/ntfs.h>
51 #include <fs/ntfs/ntfs_compr.h>
52
53 #define GET_UINT16(addr) (*((u_int16_t *)(addr)))
54
55 int
56 ntfs_uncompblock(
57 u_int8_t * dbuf,
58 u_int8_t * cbuf)
59 {
60 u_int32_t ctag;
61 int len, dshift, lmask;
62 int blen, boff;
63 int i, j;
64 int pos, cpos;
65
66 len = GET_UINT16(cbuf) & 0xFFF;
67 dprintf(("ntfs_uncompblock: block length: %d + 3, 0x%x,0x%04x\n",
68 len, len, GET_UINT16(cbuf)));
69
70 if (!(GET_UINT16(cbuf) & 0x8000)) {
71 if ((len + 1) != NTFS_COMPBLOCK_SIZE) {
72 dprintf(("ntfs_uncompblock: len: %x instead of %d\n",
73 len, 0xfff));
74 }
75 memcpy(dbuf, cbuf + 2, len + 1);
76 bzero(dbuf + len + 1, NTFS_COMPBLOCK_SIZE - 1 - len);
77 return len + 3;
78 }
79 cpos = 2;
80 pos = 0;
81 while ((cpos < len + 3) && (pos < NTFS_COMPBLOCK_SIZE)) {
82 ctag = cbuf[cpos++];
83 for (i = 0; (i < 8) && (pos < NTFS_COMPBLOCK_SIZE); i++) {
84 if (ctag & 1) {
85 for (j = pos - 1, lmask = 0xFFF, dshift = 12;
86 j >= 0x10; j >>= 1) {
87 dshift--;
88 lmask >>= 1;
89 }
90 boff = -1 - (GET_UINT16(cbuf + cpos) >> dshift);
91 blen = 3 + (GET_UINT16(cbuf + cpos) & lmask);
92 for (j = 0; (j < blen) && (pos < NTFS_COMPBLOCK_SIZE); j++) {
93 dbuf[pos] = dbuf[pos + boff];
94 pos++;
95 }
96 cpos += 2;
97 } else {
98 dbuf[pos++] = cbuf[cpos++];
99 }
100 ctag >>= 1;
101 }
102 }
103 return len + 3;
104 }
105
106 int
107 ntfs_uncompunit(
108 struct ntfsmount * ntmp,
109 u_int8_t * uup,
110 u_int8_t * cup)
111 {
112 int i;
113 int off = 0;
114 int new;
115
116 for (i = 0; i * NTFS_COMPBLOCK_SIZE < ntfs_cntob(NTFS_COMPUNIT_CL); i++) {
117 new = ntfs_uncompblock(uup + i * NTFS_COMPBLOCK_SIZE, cup + off);
118 if (new == 0)
119 return (EINVAL);
120 off += new;
121 }
122 return (0);
123 }
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