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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
/**
* ntfs_utl.c - Part of the TestDisk project.
*
* Copyright (c) 2004-2007 Christophe Grenier
*
* Original version comes from the Linux-NTFS project.
* Copyright (c) 2003 Lode Leroy
* Copyright (c) 2003 Anton Altaparmakov
* Copyright (c) 2003 Richard Russon
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (in the main directory of the Linux-NTFS
* distribution in the file COPYING); if not, write to the Free Software
* Foundation,Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#if defined(DISABLED_FOR_FRAMAC)
#undef HAVE_LIBNTFS
#undef HAVE_LIBNTFS3G
#endif
#if defined(HAVE_LIBNTFS) || defined(HAVE_LIBNTFS3G)
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <errno.h>
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_MACHINE_ENDIAN_H
#include <machine/endian.h>
#endif
#include <stdarg.h>
#include "types.h"
#ifdef HAVE_LIBNTFS
#include <ntfs/attrib.h>
#endif
#ifdef HAVE_LIBNTFS3G
#include <ntfs-3g/attrib.h>
#endif
#include "ntfs_utl.h"
#include "common.h"
#include "log.h"
/**
* find_attribute - Find an attribute of the given type
* @type: An attribute type, e.g. AT_FILE_NAME
* @ctx: A search context, created using ntfs_get_attr_search_ctx
*
* Using the search context to keep track, find the first/next occurrence of a
* given attribute type.
*
* N.B. This will return a pointer into @mft. As long as the search context
* has been created without an inode, it won't overflow the buffer.
*
* Return: Pointer Success, an attribute was found
* NULL Error, no matching attributes were found
*/
ATTR_RECORD * find_attribute(const ATTR_TYPES type, ntfs_attr_search_ctx *ctx)
{
if (!ctx) {
errno = EINVAL;
return NULL;
}
if (ntfs_attr_lookup(type, NULL, 0, CASE_SENSITIVE, 0, NULL, 0, ctx) != 0) {
#ifdef DEBUG_NTFS
log_debug("find_attribute didn't find an attribute of type: 0x%02x.\n", type);
#endif
return NULL; /* None / no more of that type */
}
#ifdef DEBUG_NTFS
log_debug("find_attribute found an attribute of type: 0x%02x.\n", type);
#endif
return ctx->attr;
}
/**
* find_first_attribute - Find the first attribute of a given type
* @type: An attribute type, e.g. AT_FILE_NAME
* @mft: A buffer containing a raw MFT record
*
* Search through a raw MFT record for an attribute of a given type.
* The return value is a pointer into the MFT record that was supplied.
*
* N.B. This will return a pointer into @mft. The pointer won't stray outside
* the buffer, since we created the search context without an inode.
*
* Return: Pointer Success, an attribute was found
* NULL Error, no matching attributes were found
*/
ATTR_RECORD * find_first_attribute(const ATTR_TYPES type, MFT_RECORD *mft)
{
ntfs_attr_search_ctx *ctx;
ATTR_RECORD *rec;
if (!mft) {
errno = EINVAL;
return NULL;
}
ctx = ntfs_attr_get_search_ctx(NULL, mft);
if (!ctx) {
log_error("Couldn't create a search context.\n");
return NULL;
}
rec = find_attribute(type, ctx);
ntfs_attr_put_search_ctx(ctx);
#ifdef DEBUG_NTFS
if (rec)
log_debug("find_first_attribute: found attr of type 0x%02x.\n", type);
else
log_debug("find_first_attribute: didn't find attr of type 0x%02x.\n", type);
#endif
return rec;
}
/**
* utils_cluster_in_use - Determine if a cluster is in use
* @vol: An ntfs volume obtained from ntfs_mount
* @lcn: The Logical Cluster Number to test
*
* The metadata file $Bitmap has one binary bit representing each cluster on
* disk. The bit will be set for each cluster that is in use. The function
* reads the relevant part of $Bitmap into a buffer and tests the bit.
*
* This function has a static buffer in which it caches a section of $Bitmap.
* If the lcn, being tested, lies outside the range, the buffer will be
* refreshed.
*
* Return: 1 Cluster is in use
* 0 Cluster is free space
* -1 Error occurred
*/
int utils_cluster_in_use(ntfs_volume *vol, long long lcn)
{
static unsigned char buffer[512];
static long long bmplcn = -sizeof(buffer) - 1; /* Which bit of $Bitmap is in the buffer */
int byte, bit;
if (!vol) {
errno = EINVAL;
return -1;
}
/* Does lcn lie in the section of $Bitmap we already have cached? */
if ((bmplcn <0 ) ||(lcn < (unsigned)bmplcn) || (lcn >= ((unsigned)bmplcn + ((unsigned)sizeof(buffer) << 3)))) {
ntfs_attr *attr;
#ifdef DEBUG_NTFS
log_debug("Bit lies outside cache.\n");
#endif
attr = ntfs_attr_open(vol->lcnbmp_ni, AT_DATA, AT_UNNAMED, 0);
if (!attr) {
log_error("Couldn't open $Bitmap\n");
return -1;
}
/* Mark the buffer as in use, in case the read is shorter. */
memset(buffer, 0xFF, sizeof(buffer));
bmplcn = lcn & (~((sizeof(buffer) << 3) - 1));
if (ntfs_attr_pread(attr, (bmplcn>>3), sizeof(buffer), buffer) < 0) {
log_error("Couldn't read $Bitmap\n");
ntfs_attr_close(attr);
return -1;
}
#ifdef DEBUG_NTFS
log_debug("Reloaded bitmap buffer.\n");
#endif
ntfs_attr_close(attr);
}
bit = 1 << (lcn & 7);
byte = (lcn >> 3) & (sizeof(buffer) - 1);
#ifdef DEBUG_NTFS
log_debug("cluster = %lld, bmplcn = %lld, byte = %d, bit = %d, in use %d\n", lcn, bmplcn, byte, bit, buffer[byte] & bit);
#endif
return (buffer[byte] & bit);
}
#endif
|
