sd_ipv4ll_set_callback  243 src/network/networkd-ipv4ll.c         r = sd_ipv4ll_set_callback(link->ipv4ll, ipv4ll_handler, link);
sd_ipv4ll_set_callback   43 src/systemd/sd-ipv4ll.h int sd_ipv4ll_set_callback(sd_ipv4ll *ll, sd_ipv4ll_cb_t cb, void *userdata);