1 /* $NetBSD: ntfs_compr.c,v 1.6 2015/02/20 17:08:13 maxv 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 1.6 2015/02/20 17:08:13 maxv Exp $");
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/namei.h>
37 #include <sys/kernel.h>
38 #include <sys/vnode.h>
39 #include <sys/mount.h>
40 #include <sys/malloc.h>
41
42 #include <fs/ntfs/ntfs.h>
43 #include <fs/ntfs/ntfs_compr.h>
44
45 #define GET_UINT16(addr) (*((u_int16_t *)(addr)))
46
47 int
ntfs_uncompblock(u_int8_t * dbuf,u_int8_t * cbuf)48 ntfs_uncompblock(u_int8_t *dbuf, u_int8_t *cbuf)
49 {
50 u_int32_t ctag;
51 int len, dshift, lmask;
52 int blen, boff;
53 int i, j;
54 int pos, cpos;
55
56 len = GET_UINT16(cbuf) & 0xFFF;
57 dprintf(("ntfs_uncompblock: block length: %d + 3, 0x%x,0x%04x\n",
58 len, len, GET_UINT16(cbuf)));
59
60 if (!(GET_UINT16(cbuf) & 0x8000)) {
61 if ((len + 1) != NTFS_COMPBLOCK_SIZE) {
62 dprintf(("ntfs_uncompblock: len: %x instead of %d\n",
63 len, 0xfff));
64 }
65 memcpy(dbuf, cbuf + 2, len + 1);
66 memset(dbuf + len + 1, 0, NTFS_COMPBLOCK_SIZE - 1 - len);
67 return len + 3;
68 }
69 cpos = 2;
70 pos = 0;
71 while ((cpos < len + 3) && (pos < NTFS_COMPBLOCK_SIZE)) {
72 ctag = cbuf[cpos++];
73 for (i = 0; (i < 8) && (pos < NTFS_COMPBLOCK_SIZE); i++) {
74 if (ctag & 1) {
75 for (j = pos - 1, lmask = 0xFFF, dshift = 12;
76 j >= 0x10; j >>= 1) {
77 dshift--;
78 lmask >>= 1;
79 }
80 boff = -1 - (GET_UINT16(cbuf + cpos) >> dshift);
81 blen = 3 + (GET_UINT16(cbuf + cpos) & lmask);
82 for (j = 0; (j < blen) && (pos < NTFS_COMPBLOCK_SIZE); j++) {
83 dbuf[pos] = dbuf[pos + boff];
84 pos++;
85 }
86 cpos += 2;
87 } else {
88 dbuf[pos++] = cbuf[cpos++];
89 }
90 ctag >>= 1;
91 }
92 }
93 return len + 3;
94 }
95
96 int
ntfs_uncompunit(struct ntfsmount * ntmp,u_int8_t * uup,u_int8_t * cup)97 ntfs_uncompunit(struct ntfsmount *ntmp, u_int8_t *uup, u_int8_t *cup)
98 {
99 int i;
100 int off = 0;
101 int new;
102
103 for (i = 0; i * NTFS_COMPBLOCK_SIZE < ntfs_cntob(NTFS_COMPUNIT_CL); i++) {
104 new = ntfs_uncompblock(uup + i * NTFS_COMPBLOCK_SIZE, cup + off);
105 if (new == 0)
106 return (EINVAL);
107 off += new;
108 }
109 return (0);
110 }
111