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 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 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
