send_icmp
check_icmp_add(&env->sc_icmp_send, EV_WRITE, tv, send_icmp);
check_icmp_add(&env->sc_icmp6_send, EV_WRITE, tv, send_icmp);
event_again(&cie->ev, s, EV_TIMEOUT|EV_WRITE, send_icmp,
void send_icmp(int, short, void *);