int r=sendto(us->fd,buf->start,buf->size,
0,&dest->ia.sa,iaddr_socklen(&dest->ia));
udp_sock_experienced(0,&st->uc,&interf->socks,us,
int r=sendto(us->fd,buf->start,buf->size,
0,&dest->ia.sa,iaddr_socklen(&dest->ia));
udp_sock_experienced(0,&st->uc,&interf->socks,us,