+int dccp_feat_activate_values(struct sock *sk, struct list_head *fn_list)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct dccp_feat_entry *cur, *next;
+ int idx;
+ dccp_feat_val *fvals[DCCP_FEAT_SUPPORTED_MAX][2] = {
+ [0 ... DCCP_FEAT_SUPPORTED_MAX-1] = { NULL, NULL }
+ };
+
+ list_for_each_entry(cur, fn_list, node) {
+ /*
+ * An empty Confirm means that either an unknown feature type
+ * or an invalid value was present. In the first case there is
+ * nothing to activate, in the other the default value is used.
+ */
+ if (cur->empty_confirm)
+ continue;
+
+ idx = dccp_feat_index(cur->feat_num);
+ if (idx < 0) {
+ DCCP_BUG("Unknown feature %u", cur->feat_num);
+ goto activation_failed;
+ }
+ if (cur->state != FEAT_STABLE) {
+ DCCP_CRIT("Negotiation of %s %u failed in state %u",
+ cur->is_local ? "local" : "remote",
+ cur->feat_num, cur->state);
+ goto activation_failed;
+ }
+ fvals[idx][cur->is_local] = &cur->val;
+ }
+
+ /*
+ * Activate in decreasing order of index, so that the CCIDs are always
+ * activated as the last feature. This avoids the case where a CCID
+ * relies on the initialisation of one or more features that it depends
+ * on (e.g. Send NDP Count, Send Ack Vector, and Ack Ratio features).
+ */
+ for (idx = DCCP_FEAT_SUPPORTED_MAX; --idx >= 0;)
+ if (__dccp_feat_activate(sk, idx, 0, fvals[idx][0]) ||
+ __dccp_feat_activate(sk, idx, 1, fvals[idx][1])) {
+ DCCP_CRIT("Could not activate %d", idx);
+ goto activation_failed;
+ }
+
+ /* Clean up Change options which have been confirmed already */
+ list_for_each_entry_safe(cur, next, fn_list, node)
+ if (!cur->needs_confirm)
+ dccp_feat_list_pop(cur);
+
+ dccp_pr_debug("Activation OK\n");
+ return 0;
+
+activation_failed:
+ /*
+ * We clean up everything that may have been allocated, since
+ * it is difficult to track at which stage negotiation failed.
+ * This is ok, since all allocation functions below are robust
+ * against NULL arguments.
+ */
+ ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
+ ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
+ dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
+ dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
+ dp->dccps_hc_rx_ackvec = NULL;
+ return -1;
+}
+