IFA_FREEBSD
int off = snl_add_msg_attr_nested(&nw, IFA_FREEBSD);
int off = snl_add_msg_attr_nested(&nw, IFA_FREEBSD);
{ .type = IFA_FREEBSD, .arg = &_addr_fbsd_parser, .cb = snl_attr_get_nested },
int off = nlattr_add_nested(nw, IFA_FREEBSD);
{ .type = IFA_FREEBSD, .arg = &ifa_fbsd_parser, .cb = nlattr_get_nested },