+int sd_network_link_get_setup_state(int ifindex, char **state);
+
+/* Get operational state from ifindex.
+ * Possible states:
+ * off: the device is powered down
+ * no-carrier: the device is powered up, but it does not yet have a carrier
+ * dormant: the device has a carrier, but is not yet ready for normal traffic
+ * carrier: the link has a carrier
+ * degraded: the link has carrier and addresses valid on the local link configured
+ * routable: the link has carrier and routable address configured
+ * Possible return codes:
+ * -ENODATA: networkd is not aware of the link
+ */
+int sd_network_link_get_operational_state(int ifindex, char **state);
+
+/* Get path to .network file applied to link */
+int sd_network_link_get_network_file(int ifindex, char **filename);