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
|
/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* 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; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <asm/posix_types.h>
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include "libbb.h"
/* Grumble... The 2.6.x kernel breaks asm/posix_types.h
* so we get to try and cope as best we can... */
#include <linux/version.h>
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
#define __bb_kernel_dev_t __kernel_old_dev_t
#elif LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
#define __bb_kernel_dev_t __kernel_dev_t
#else
#define __bb_kernel_dev_t unsigned short
#endif
/* Stuff stolen from linux/loop.h */
#define LO_NAME_SIZE 64
#define LO_KEY_SIZE 32
#define LOOP_SET_FD 0x4C00
#define LOOP_CLR_FD 0x4C01
#define LOOP_SET_STATUS 0x4C02
#define LOOP_GET_STATUS 0x4C03
struct loop_info {
int lo_number;
__bb_kernel_dev_t lo_device;
unsigned long lo_inode;
__bb_kernel_dev_t lo_rdevice;
int lo_offset;
int lo_encrypt_type;
int lo_encrypt_key_size;
int lo_flags;
char lo_name[LO_NAME_SIZE];
unsigned char lo_encrypt_key[LO_KEY_SIZE];
unsigned long lo_init[2];
char reserved[4];
};
extern int del_loop(const char *device)
{
int fd;
if ((fd = open(device, O_RDONLY)) < 0) {
bb_perror_msg("%s", device);
return (FALSE);
}
if (ioctl(fd, LOOP_CLR_FD, 0) < 0) {
close(fd);
bb_perror_msg("ioctl: LOOP_CLR_FD");
return (FALSE);
}
close(fd);
return (TRUE);
}
extern int set_loop(const char *device, const char *file, int offset,
int *loopro)
{
struct loop_info loopinfo;
int fd, ffd, mode;
mode = *loopro ? O_RDONLY : O_RDWR;
if ((ffd = open(file, mode)) < 0 && !*loopro
&& (errno != EROFS || (ffd = open(file, mode = O_RDONLY)) < 0)) {
bb_perror_msg("%s", file);
return 1;
}
if ((fd = open(device, mode)) < 0) {
close(ffd);
bb_perror_msg("%s", device);
return 1;
}
*loopro = (mode == O_RDONLY);
memset(&loopinfo, 0, sizeof(loopinfo));
safe_strncpy(loopinfo.lo_name, file, LO_NAME_SIZE);
loopinfo.lo_offset = offset;
loopinfo.lo_encrypt_key_size = 0;
if (ioctl(fd, LOOP_SET_FD, ffd) < 0) {
bb_perror_msg("ioctl: LOOP_SET_FD");
close(fd);
close(ffd);
return 1;
}
if (ioctl(fd, LOOP_SET_STATUS, &loopinfo) < 0) {
(void) ioctl(fd, LOOP_CLR_FD, 0);
bb_perror_msg("ioctl: LOOP_SET_STATUS");
close(fd);
close(ffd);
return 1;
}
close(fd);
close(ffd);
return 0;
}
extern char *find_unused_loop_device(void)
{
char dev[20];
int i, fd;
struct stat statbuf;
struct loop_info loopinfo;
for (i = 0; i <= 7; i++) {
sprintf(dev, LOOP_FORMAT, i);
if (stat(dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) {
if ((fd = open(dev, O_RDONLY)) >= 0) {
if (ioctl(fd, LOOP_GET_STATUS, &loopinfo) != 0) {
if (errno == ENXIO) { /* probably free */
close(fd);
return strdup(dev);
}
}
close(fd);
}
}
}
return NULL;
}
/* END CODE */
/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/
|
