l2cap_getopt
int l2cap_getopt(struct l2cap_channel *, struct sockopt *);
err = l2cap_getopt(pcb, sopt);
(void)l2cap_getopt(so->so_pcb, &sopt);
(void)l2cap_getopt(rs->rs_l2cap, &sopt);
(void)l2cap_getopt(rs->rs_l2cap, &sopt);