#include <fcntl.h>
#include <sys/mount.h>
+#include <systemd/sd-id128.h>
+
#include "machine-id-setup.h"
#include "macro.h"
#include "util.h"
#include "log.h"
+#include "virt.h"
+
+static int shorten_uuid(char destination[36], const char *source) {
+ unsigned i, j;
+
+ for (i = 0, j = 0; i < 36 && j < 32; i++) {
+ int t;
-static void make_v4_uuid(unsigned char *id) {
- /* Stolen from generate_random_uuid() of drivers/char/random.c
- * in the kernel sources */
+ t = unhexchar(source[i]);
+ if (t < 0)
+ continue;
- /* Set UUID version to 4 --- truly random generation */
- id[6] = (id[6] & 0x0F) | 0x40;
+ destination[j++] = hexchar(t);
+ }
+
+ if (i == 36 && j == 32) {
+ destination[32] = '\n';
+ destination[33] = 0;
+ return 0;
+ }
- /* Set the UUID variant to DCE */
- id[8] = (id[8] & 0x3F) | 0x80;
+ return -EINVAL;
}
static int generate(char id[34]) {
- int fd;
- unsigned char buf[16], *p;
+ int fd, r;
+ unsigned char *p;
+ sd_id128_t buf;
char *q;
ssize_t k;
+ const char *vm_id;
assert(id);
fd = open("/var/lib/dbus/machine-id", O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
if (fd >= 0) {
- k = loop_read(fd, id, 33, false);
+ k = loop_read(fd, id, 32, false);
close_nointr_nofail(fd);
if (k >= 32) {
}
}
- /* If that didn't work, generate a random machine id */
- fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
- if (fd < 0) {
- log_error("Failed to open /dev/urandom: %m");
- return -errno;
+ /* If that didn't work, see if we are running in qemu/kvm and a
+ * machine ID was passed in via -uuid on the qemu/kvm command
+ * line */
+
+ r = detect_vm(&vm_id);
+ if (r > 0 && streq(vm_id, "kvm")) {
+ char uuid[37];
+
+ fd = open("/sys/class/dmi/id/product_uuid", O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+ if (fd >= 0) {
+ k = loop_read(fd, uuid, 36, false);
+ close_nointr_nofail(fd);
+
+ if (k >= 36) {
+ r = shorten_uuid(id, uuid);
+ if (r >= 0) {
+ log_info("Initializing machine ID from KVM UUID");
+ return 0;
+ }
+ }
+ }
}
- k = loop_read(fd, buf, sizeof(buf), false);
- close_nointr_nofail(fd);
+ /* If that didn't work either, see if we are running in a
+ * container, and a machine ID was passed in via
+ * $container_uuid the way libvirt/LXC does it */
+
+ r = detect_container(NULL);
+ if (r > 0) {
+ FILE *f;
- if (k != sizeof(buf)) {
- log_error("Failed to read /dev/urandom: %s", strerror(k < 0 ? -k : EIO));
- return k < 0 ? (int) k : -EIO;
+ f = fopen("/proc/1/environ", "re");
+ if (f) {
+ bool done = false;
+
+ do {
+ char line[LINE_MAX];
+ unsigned i;
+
+ for (i = 0; i < sizeof(line)-1; i++) {
+ int c;
+
+ c = getc(f);
+ if (_unlikely_(c == EOF)) {
+ done = true;
+ break;
+ } else if (c == 0)
+ break;
+
+ line[i] = c;
+ }
+ line[i] = 0;
+
+ if (startswith(line, "container_uuid=") &&
+ strlen(line + 15) >= 36) {
+ r = shorten_uuid(id, line + 15);
+ if (r >= 0) {
+ log_info("Initializing machine ID from container UUID");
+ return 0;
+ }
+ }
+
+ } while (!done);
+
+ fclose(f);
+ }
}
- /* Turn this into a valid v4 UUID, to be nice. Note that we
- * only guarantee this for newly generated UUIDs, not for
- * pre-existing ones.*/
- make_v4_uuid(buf);
+ /* If that didn't work, generate a random machine id */
+ r = sd_id128_randomize(&buf);
+ if (r < 0) {
+ log_error("Failed to open /dev/urandom: %s", strerror(-r));
+ return r;
+ }
- for (p = buf, q = id; p < buf + sizeof(buf); p++, q += 2) {
+ for (p = buf.bytes, q = id; p < buf.bytes + sizeof(buf); p++, q += 2) {
q[0] = hexchar(*p >> 4);
q[1] = hexchar(*p & 15);
}