+/**
+ * dccp_feat_insert_opts - Generate FN options from current list state
+ * @skb: next sk_buff to be sent to the peer
+ * @dp: for client during handshake and general negotiation
+ * @dreq: used by the server only (all Changes/Confirms in LISTEN/RESPOND)
+ */
+int dccp_feat_insert_opts(struct dccp_sock *dp, struct dccp_request_sock *dreq,
+ struct sk_buff *skb)
+{
+ struct list_head *fn = dreq ? &dreq->dreq_featneg : &dp->dccps_featneg;
+ struct dccp_feat_entry *pos, *next;
+ u8 opt, type, len, *ptr, nn_in_nbo[DCCP_OPTVAL_MAXLEN];
+ bool rpt;
+
+ /* put entries into @skb in the order they appear in the list */
+ list_for_each_entry_safe_reverse(pos, next, fn, node) {
+ opt = dccp_feat_genopt(pos);
+ type = dccp_feat_type(pos->feat_num);
+ rpt = false;
+
+ if (pos->empty_confirm) {
+ len = 0;
+ ptr = NULL;
+ } else {
+ if (type == FEAT_SP) {
+ len = pos->val.sp.len;
+ ptr = pos->val.sp.vec;
+ rpt = pos->needs_confirm;
+ } else if (type == FEAT_NN) {
+ len = dccp_feat_valid_nn_length(pos->feat_num);
+ ptr = nn_in_nbo;
+ dccp_encode_value_var(pos->val.nn, ptr, len);
+ } else {
+ DCCP_BUG("unknown feature %u", pos->feat_num);
+ return -1;
+ }
+ }
+
+ if (dccp_insert_fn_opt(skb, opt, pos->feat_num, ptr, len, rpt))
+ return -1;
+ if (pos->needs_mandatory && dccp_insert_option_mandatory(skb))
+ return -1;
+ /*
+ * Enter CHANGING after transmitting the Change option (6.6.2).
+ */
+ if (pos->state == FEAT_INITIALISING)
+ pos->state = FEAT_CHANGING;
+ }
+ return 0;
+}
+