sd_dhcp_client_attach_event  598 src/network/networkd-dhcp4.c         r = sd_dhcp_client_attach_event(link->dhcp_client, NULL, 0);
sd_dhcp_client_attach_event   67 src/systemd/sd-dhcp-client.h int sd_dhcp_client_attach_event(sd_dhcp_client *client, sd_event *event, int priority);