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
|
/*
* Guillaume Cottenceau (gc)
*
* Copyright 2000 Mandriva
*
* This software may be freely redistributed under the terms of the GNU
* public license.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
/* This code comes from util-linux-2.10n (mount/lomount.c)
* (this is a simplified version of this code)
*/
#include <sys/types.h>
#include <sys/mount.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "stage1.h"
#include "frontend.h"
#include "log.h"
#include "mount.h"
#include "modules.h"
#include "lomount.h"
#define LO_NAME_SIZE 64
#define LO_KEY_SIZE 32
struct loop_info
{
int lo_number; /* ioctl r/o */
dev_t lo_device; /* ioctl r/o */
unsigned long lo_inode; /* ioctl r/o */
dev_t lo_rdevice; /* ioctl r/o */
int lo_offset;
int lo_encrypt_type;
int lo_encrypt_key_size; /* ioctl w/o */
int lo_flags; /* ioctl r/o */
char lo_name[LO_NAME_SIZE];
unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
unsigned long lo_init[2];
char reserved[4];
};
#define LOOP_SET_FD 0x4C00
#define LOOP_CLR_FD 0x4C01
#define LOOP_SET_STATUS 0x4C02
#define LOOP_GET_STATUS 0x4C03
int
set_loop (const char *device, const char *file)
{
struct loop_info loopinfo;
int fd, ffd, mode;
mode = O_RDONLY;
if ((ffd = open (file, mode)) < 0)
return 1;
if ((fd = open (device, mode)) < 0) {
close(ffd);
return 1;
}
memset(&loopinfo, 0, sizeof (loopinfo));
strncpy(loopinfo.lo_name, file, LO_NAME_SIZE);
loopinfo.lo_name[LO_NAME_SIZE - 1] = 0;
loopinfo.lo_offset = 0;
#ifdef MCL_FUTURE
/*
* Oh-oh, sensitive data coming up. Better lock into memory to prevent
* passwd etc being swapped out and left somewhere on disk.
*/
if(mlockall(MCL_CURRENT|MCL_FUTURE)) {
log_message("CRITICAL Couldn't lock into memory! %s (memlock)", strerror(errno));
return 1;
}
#endif
if (ioctl(fd, LOOP_SET_FD, ffd) < 0) {
close(fd);
close(ffd);
return 1;
}
if (ioctl(fd, LOOP_SET_STATUS, &loopinfo) < 0) {
(void) ioctl (fd, LOOP_CLR_FD, 0);
close(fd);
close(ffd);
return 1;
}
close(fd);
close(ffd);
return 0;
}
char* find_free_loop()
{
struct loop_info loopinfo;
int i;
for (i=0; i<256; i++) {
int fd;
char ldev[100];
sprintf(ldev, "/dev/loop%d", i);
ensure_dev_exists(ldev);
fd = open(ldev, O_RDONLY);
if (!ioctl(fd, LOOP_GET_STATUS, &loopinfo)) {
close(fd);
continue;
}
if (errno == ENXIO) {
log_message("%s is available", ldev);
close(fd);
return strdup(ldev);
} else {
log_perror("LOOP_GET_STATUS(unexpected error)");
close(fd);
continue;
}
}
return NULL;
}
void
del_loop(char * loopdev)
{
int fd;
if (!loopdev)
return;
if ((fd = open (loopdev, O_RDONLY)) < 0)
return;
if (ioctl (fd, LOOP_CLR_FD, 0) < 0)
return;
close (fd);
}
int
lomount(char *loopfile, char *where, char **dev, int compressed)
{
long int flag;
char * loopdev;
flag = MS_MGC_VAL;
flag |= MS_RDONLY;
my_insmod("loop", ANY_DRIVER_TYPE, "max_loop=256", 1);
if (compressed) {
my_insmod("squashfs", ANY_DRIVER_TYPE, NULL, 1);
}
if (!(loopdev = find_free_loop())) {
log_message("could not find a free loop");
return 1;
}
if (dev)
*dev = loopdev;
if (set_loop(loopdev, loopfile)) {
log_message("set_loop failed on %s (%s)", loopdev, strerror(errno));
return 1;
}
if (my_mount(loopdev, where, compressed ? "squashfs" : "iso9660", 0)) {
del_loop(loopdev);
return 1;
}
log_message("lomount succeeded for %s on %s", loopfile, where);
return 0;
}
|
