sd_dhcp_client_ref 72 src/libsystemd-network/dhcp-internal.h _cleanup_dhcp_client_unref_ _unused_ sd_dhcp_client *_dont_destroy_##client = sd_dhcp_client_ref(client) sd_dhcp_client_ref 62 src/systemd/sd-dhcp-client.h sd_dhcp_client *sd_dhcp_client_ref(sd_dhcp_client *client);