+/*
+ * Feature activation handlers.
+ *
+ * These all use an u64 argument, to provide enough room for NN/SP features. At
+ * this stage the negotiated values have been checked to be within their range.
+ */
+static int dccp_hdlr_ccid(struct sock *sk, u64 ccid, bool rx)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid *new_ccid = ccid_new(ccid, sk, rx, gfp_any());
+
+ if (new_ccid == NULL)
+ return -ENOMEM;
+
+ if (rx) {
+ ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
+ dp->dccps_hc_rx_ccid = new_ccid;
+ } else {
+ ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
+ dp->dccps_hc_tx_ccid = new_ccid;
+ }
+ return 0;
+}
+
+static int dccp_hdlr_seq_win(struct sock *sk, u64 seq_win, bool rx)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+
+ if (rx) {
+ dp->dccps_r_seq_win = seq_win;
+ /* propagate changes to update SWL/SWH */
+ dccp_update_gsr(sk, dp->dccps_gsr);
+ } else {
+ dp->dccps_l_seq_win = seq_win;
+ /* propagate changes to update AWL */
+ dccp_update_gss(sk, dp->dccps_gss);
+ }
+ return 0;
+}
+
+static int dccp_hdlr_ack_ratio(struct sock *sk, u64 ratio, bool rx)
+{
+ if (rx)
+ dccp_sk(sk)->dccps_r_ack_ratio = ratio;
+ else
+ dccp_sk(sk)->dccps_l_ack_ratio = ratio;
+ return 0;
+}
+
+static int dccp_hdlr_ackvec(struct sock *sk, u64 enable, bool rx)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+
+ if (rx) {
+ if (enable && dp->dccps_hc_rx_ackvec == NULL) {
+ dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(gfp_any());
+ if (dp->dccps_hc_rx_ackvec == NULL)
+ return -ENOMEM;
+ } else if (!enable) {
+ dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
+ dp->dccps_hc_rx_ackvec = NULL;
+ }
+ }
+ return 0;
+}
+
+static int dccp_hdlr_ndp(struct sock *sk, u64 enable, bool rx)
+{
+ if (!rx)
+ dccp_sk(sk)->dccps_send_ndp_count = (enable > 0);
+ return 0;
+}
+
+/*
+ * Minimum Checksum Coverage is located at the RX side (9.2.1). This means that
+ * `rx' holds when the sending peer informs about his partial coverage via a
+ * ChangeR() option. In the other case, we are the sender and the receiver
+ * announces its coverage via ChangeL() options. The policy here is to honour
+ * such communication by enabling the corresponding partial coverage - but only
+ * if it has not been set manually before; the warning here means that all
+ * packets will be dropped.
+ */
+static int dccp_hdlr_min_cscov(struct sock *sk, u64 cscov, bool rx)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+
+ if (rx)
+ dp->dccps_pcrlen = cscov;
+ else {
+ if (dp->dccps_pcslen == 0)
+ dp->dccps_pcslen = cscov;
+ else if (cscov > dp->dccps_pcslen)
+ DCCP_WARN("CsCov %u too small, peer requires >= %u\n",
+ dp->dccps_pcslen, (u8)cscov);
+ }
+ return 0;
+}