1 #include <stdio.h>
2 #include <fcntl.h>
3 #include <unistd.h>
4 #include <sys/ioctl.h>
5 #include <linux/dm-ioctl.h>
6 #include <stdlib.h>
7 #include <string.h>
8
9 #define DM_CRYPT_BUF_SIZE 4096
10
ioctl_init(struct dm_ioctl * io,size_t dataSize,const char * name,unsigned flags)11 static void ioctl_init(struct dm_ioctl *io, size_t dataSize, const char *name, unsigned flags)
12 {
13 memset(io, 0, dataSize);
14 io->data_size = dataSize;
15 io->data_start = sizeof(struct dm_ioctl);
16 io->version[0] = 4;
17 io->version[1] = 0;
18 io->version[2] = 0;
19 io->flags = flags;
20 if (name) {
21 strncpy(io->name, name, sizeof(io->name));
22 }
23 }
24
main(int argc,char * argv[])25 int main(int argc, char *argv[])
26 {
27 char buffer[DM_CRYPT_BUF_SIZE];
28 struct dm_ioctl *io;
29 struct dm_target_versions *v;
30 int fd;
31
32 fd = open("/dev/device-mapper", O_RDWR);
33 if (fd < 0) {
34 fprintf(stderr, "Cannot open /dev/device-mapper\n");
35 exit(1);
36 }
37
38 io = (struct dm_ioctl *) buffer;
39
40 ioctl_init(io, DM_CRYPT_BUF_SIZE, NULL, 0);
41
42 if (ioctl(fd, DM_LIST_VERSIONS, io)) {
43 fprintf(stderr, "ioctl(DM_LIST_VERSIONS) returned an error\n");
44 exit(1);
45 }
46
47 /* Iterate over the returned versions, and print each subsystem's version */
48 v = (struct dm_target_versions *) &buffer[sizeof(struct dm_ioctl)];
49 while (v->next) {
50 printf("%s: %d.%d.%d\n", v->name, v->version[0], v->version[1], v->version[2]);
51 v = (struct dm_target_versions *)(((char *)v) + v->next);
52 }
53
54 close(fd);
55 exit(0);
56 }
57
58