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 |
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 |
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 | |