send_direct_ack
send_direct_ack(nbr->iface, nbr->addr, imsg.data,
int send_direct_ack(struct iface *, struct in6_addr, void *, size_t);
send_direct_ack(nbr->iface, nbr->addr, imsg.data,
int send_direct_ack(struct iface *, struct in_addr, void *, size_t);