#include #include #include #include #include #include #include #define DM_CRYPT_BUF_SIZE 4096 static void ioctl_init(struct dm_ioctl *io, size_t dataSize, const char *name, unsigned flags) { memset(io, 0, dataSize); io->data_size = dataSize; io->data_start = sizeof(struct dm_ioctl); io->version[0] = 4; io->version[1] = 0; io->version[2] = 0; io->flags = flags; if (name) { strncpy(io->name, name, sizeof(io->name)); } } int main(int argc, char *argv[]) { char buffer[DM_CRYPT_BUF_SIZE]; struct dm_ioctl *io; struct dm_target_versions *v; int fd; fd = open("/dev/device-mapper", O_RDWR); if (fd < 0) { fprintf(stderr, "Cannot open /dev/device-mapper\n"); exit(1); } io = (struct dm_ioctl *) buffer; ioctl_init(io, DM_CRYPT_BUF_SIZE, NULL, 0); if (ioctl(fd, DM_LIST_VERSIONS, io)) { fprintf(stderr, "ioctl(DM_LIST_VERSIONS) returned an error\n"); exit(1); } /* Iterate over the returned versions, and print each subsystem's version */ v = (struct dm_target_versions *) &buffer[sizeof(struct dm_ioctl)]; while (v->next) { printf("%s: %d.%d.%d\n", v->name, v->version[0], v->version[1], v->version[2]); v = (struct dm_target_versions *)(((char *)v) + v->next); } close(fd); exit(0); }