PF_RT_RETURN_ICMP6
snl_add_msg_attr_u16(nw, PF_RT_RETURN_ICMP6, r->return_icmp6);
{ .type = PF_RT_RETURN_ICMP6, .off = _OUT(r.return_icmp6), .cb = snl_attr_get_uint16 },
{ .type = PF_RT_RETURN_ICMP6, .off = _OUT(return_icmp6), .cb = nlattr_get_uint16 },
nlattr_add_u16(nw, PF_RT_RETURN_ICMP6, rule->return_icmp6);
nlattr_add_u16(nw, PF_RT_RETURN_ICMP6, rule->return_icmp6);