ctl_transact
ctl_transact(my_machine_addr, msg, DELETE, &response);
ctl_transact(his_machine_addr, msg, DELETE, &response);
ctl_transact(his_machine_addr, msg, ANNOUNCE, &response);
ctl_transact(my_machine_addr, msg, LEAVE_INVITE, &response);
ctl_transact(his_machine_addr, msg, LOOK_UP, rp);
ctl_transact(his_machine_addr, msg, DELETE, rp);
void ctl_transact(struct in_addr, CTL_MSG, int, CTL_RESPONSE *);