diff options
Diffstat (limited to 'losetup.c')
-rw-r--r-- | losetup.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/losetup.c b/losetup.c new file mode 100644 index 000000000..2908dbc88 --- /dev/null +++ b/losetup.c | |||
@@ -0,0 +1,190 @@ | |||
1 | /* | ||
2 | * losetup.c - setup and control loop devices | ||
3 | */ | ||
4 | |||
5 | |||
6 | #include "internal.h" | ||
7 | |||
8 | const char losetup_usage[] = "losetup\n" | ||
9 | "\n" | ||
10 | "\tlosetup loop_device give info\n" | ||
11 | "\tlosetup -d loop_device delete\n" | ||
12 | "\tlosetup [ -o offset ] loop_device file setup\n"; | ||
13 | |||
14 | /* from mount-2.6d */ | ||
15 | |||
16 | /* | ||
17 | * losetup.c - setup and control loop devices | ||
18 | */ | ||
19 | |||
20 | #include <stdio.h> | ||
21 | #include <string.h> | ||
22 | #include <ctype.h> | ||
23 | #include <fcntl.h> | ||
24 | #include <unistd.h> | ||
25 | #include <getopt.h> | ||
26 | #include <errno.h> | ||
27 | #include <sys/ioctl.h> | ||
28 | #include <linux/fs.h> | ||
29 | /* #include "loop.h" */ | ||
30 | |||
31 | /* | ||
32 | * include/linux/loop.h | ||
33 | * | ||
34 | * Written by Theodore Ts'o, 3/29/93. | ||
35 | * | ||
36 | * Copyright 1993 by Theodore Ts'o. Redistribution of this file is | ||
37 | * permitted under the GNU Public License. | ||
38 | */ | ||
39 | |||
40 | #define LO_NAME_SIZE 64 | ||
41 | #define LO_KEY_SIZE 32 | ||
42 | |||
43 | struct loop_info { | ||
44 | int lo_number; /* ioctl r/o */ | ||
45 | dev_t lo_device; /* ioctl r/o */ | ||
46 | unsigned long lo_inode; /* ioctl r/o */ | ||
47 | dev_t lo_rdevice; /* ioctl r/o */ | ||
48 | int lo_offset; | ||
49 | int lo_encrypt_type; | ||
50 | int lo_encrypt_key_size; /* ioctl w/o */ | ||
51 | int lo_flags; /* ioctl r/o */ | ||
52 | char lo_name[LO_NAME_SIZE]; | ||
53 | unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */ | ||
54 | unsigned long lo_init[2]; | ||
55 | char reserved[4]; | ||
56 | }; | ||
57 | |||
58 | /* | ||
59 | * IOCTL commands --- we will commandeer 0x4C ('L') | ||
60 | */ | ||
61 | |||
62 | #define LOOP_SET_FD 0x4C00 | ||
63 | #define LOOP_CLR_FD 0x4C01 | ||
64 | #define LOOP_SET_STATUS 0x4C02 | ||
65 | #define LOOP_GET_STATUS 0x4C03 | ||
66 | |||
67 | /* #include "lomount.h" */ | ||
68 | |||
69 | extern int set_loop (const char *, const char *, int, int *); | ||
70 | extern int del_loop (const char *); | ||
71 | |||
72 | static void show_loop(const char *device) | ||
73 | { | ||
74 | struct loop_info loopinfo; | ||
75 | int fd; | ||
76 | |||
77 | if ((fd = open(device, O_RDWR)) < 0) { | ||
78 | perror(device); | ||
79 | return; | ||
80 | } | ||
81 | if (ioctl(fd, LOOP_GET_STATUS, &loopinfo) < 0) { | ||
82 | perror("Cannot get loop info"); | ||
83 | close(fd); | ||
84 | return; | ||
85 | } | ||
86 | printf("%s: [%04x]:%ld (%s) offset %d\n", | ||
87 | device, (unsigned int)loopinfo.lo_device, loopinfo.lo_inode, | ||
88 | loopinfo.lo_name, loopinfo.lo_offset); | ||
89 | close(fd); | ||
90 | } | ||
91 | |||
92 | |||
93 | int set_loop(const char *device, const char *file, int offset, int *loopro) | ||
94 | { | ||
95 | struct loop_info loopinfo; | ||
96 | int fd, ffd, mode; | ||
97 | |||
98 | mode = *loopro ? O_RDONLY : O_RDWR; | ||
99 | if ((ffd = open (file, mode)) < 0 && !*loopro | ||
100 | && (errno != EROFS || (ffd = open (file, mode = O_RDONLY)) < 0)) { | ||
101 | perror (file); | ||
102 | return 1; | ||
103 | } | ||
104 | if ((fd = open (device, mode)) < 0) { | ||
105 | close(ffd); | ||
106 | perror (device); | ||
107 | return 1; | ||
108 | } | ||
109 | *loopro = (mode == O_RDONLY); | ||
110 | |||
111 | memset(&loopinfo, 0, sizeof(loopinfo)); | ||
112 | strncpy(loopinfo.lo_name, file, LO_NAME_SIZE); | ||
113 | loopinfo.lo_name[LO_NAME_SIZE-1] = 0; | ||
114 | |||
115 | loopinfo.lo_offset = offset; | ||
116 | |||
117 | loopinfo.lo_encrypt_key_size = 0; | ||
118 | if (ioctl(fd, LOOP_SET_FD, ffd) < 0) { | ||
119 | perror("ioctl: LOOP_SET_FD"); | ||
120 | exit(1); | ||
121 | } | ||
122 | if (ioctl(fd, LOOP_SET_STATUS, &loopinfo) < 0) { | ||
123 | (void) ioctl(fd, LOOP_CLR_FD, 0); | ||
124 | perror("ioctl: LOOP_SET_STATUS"); | ||
125 | exit(1); | ||
126 | } | ||
127 | close(fd); | ||
128 | close(ffd); | ||
129 | return 0; | ||
130 | } | ||
131 | |||
132 | int del_loop(const char *device) | ||
133 | { | ||
134 | int fd; | ||
135 | |||
136 | if ((fd = open(device, O_RDONLY)) < 0) { | ||
137 | perror(device); | ||
138 | exit(1); | ||
139 | } | ||
140 | if (ioctl(fd, LOOP_CLR_FD, 0) < 0) { | ||
141 | perror("ioctl: LOOP_CLR_FD"); | ||
142 | exit(1); | ||
143 | } | ||
144 | close(fd); | ||
145 | return(0); | ||
146 | } | ||
147 | |||
148 | |||
149 | static int losetup_usage_fn(void) | ||
150 | { | ||
151 | fprintf(stderr, losetup_usage); | ||
152 | exit(1); | ||
153 | } | ||
154 | |||
155 | int losetup_main(struct FileInfo * i, int argc, char * * argv) | ||
156 | { | ||
157 | char *offset; | ||
158 | int delete,off,c; | ||
159 | int ro = 0; | ||
160 | |||
161 | delete = off = 0; | ||
162 | offset = NULL; | ||
163 | while ((c = getopt(argc,argv,"do:")) != EOF) { | ||
164 | switch (c) { | ||
165 | case 'd': | ||
166 | delete = 1; | ||
167 | break; | ||
168 | case 'o': | ||
169 | offset = optarg; | ||
170 | break; | ||
171 | default: | ||
172 | losetup_usage_fn(); | ||
173 | } | ||
174 | } | ||
175 | if (argc == 1) losetup_usage_fn(); | ||
176 | if ((delete && (argc != optind+1 || offset)) || | ||
177 | (!delete && (argc < optind+1 || argc > optind+2))) | ||
178 | losetup_usage_fn(); | ||
179 | if (argc == optind+1) | ||
180 | if (delete) | ||
181 | del_loop(argv[optind]); | ||
182 | else | ||
183 | show_loop(argv[optind]); | ||
184 | else { | ||
185 | if (offset && sscanf(offset,"%d",&off) != 1) | ||
186 | losetup_usage_fn(); | ||
187 | set_loop(argv[optind],argv[optind+1],off,&ro); | ||
188 | } | ||
189 | return 0; | ||
190 | } | ||