/* dccp_insert_option_mandatory - Mandatory option (5.8.2) Note that since we are using skb_push, this function needs to be called  */
int dccp_insert_option_mandatory(struct sk_buff *skb)
/* dccp_insert_option_mandatory - Mandatory option (5.8.2) Note that since we are using skb_push, this function needs to be called  */
int dccp_insert_option_mandatory(struct sk_buff *skb)
{
	if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN)
		return -1;
	DCCP_SKB_CB(skb)->dccpd_opt_len++;
	*skb_push(skb, 1) = DCCPO_MANDATORY;
	return 0;
}