nd6_option_init
nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
void nd6_option_init(void *, int, union nd_opts *);
nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
nd6_option_init(nd_na + 1, icmp6len, &ndopts);
nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
nd6_option_init(nd_ra + 1, icmp6len, &ndopts);