+static int client_ensure_iaid(sd_dhcp6_client *client) {
+ const char *name = NULL;
+ uint64_t id;
+
+ assert(client);
+
+ if (client->ia_na.id)
+ return 0;
+
+ if (detect_container(NULL) <= 0) {
+ /* not in a container, udev will be around */
+ _cleanup_udev_unref_ struct udev *udev;
+ _cleanup_udev_device_unref_ struct udev_device *device;
+ char ifindex_str[2 + DECIMAL_STR_MAX(int)];
+
+ udev = udev_new();
+ if (!udev)
+ return -ENOMEM;
+
+ sprintf(ifindex_str, "n%d", client->index);
+ device = udev_device_new_from_device_id(udev, ifindex_str);
+ if (!device)
+ return -errno;
+
+ if (udev_device_get_is_initialized(device) <= 0)
+ /* not yet ready */
+ return -EBUSY;
+
+ name = net_get_name(device);
+ }
+
+ if (name)
+ siphash24((uint8_t*)&id, name, strlen(name), HASH_KEY.bytes);
+ else
+ /* fall back to mac address if no predictable name available */
+ siphash24((uint8_t*)&id, &client->mac_addr, ETH_ALEN,
+ HASH_KEY.bytes);
+
+ /* fold into 32 bits */
+ client->ia_na.id = (id & 0xffffffff) ^ (id >> 32);
+
+ return 0;
+}
+
+static int client_start(sd_dhcp6_client *client)
+{
+ int r;
+
+ assert_return(client, -EINVAL);
+ assert_return(client->event, -EINVAL);
+ assert_return(client->index > 0, -EINVAL);
+
+ r = client_ensure_iaid(client);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+