+ dccp_shutdown_clients();
+ generic_acl_deplete(&dss->acl);
+ free_sender_status(dss);
+}
+
+#ifndef DCCP_SOCKOPT_GET_CUR_MPS
+#define DCCP_SOCKOPT_GET_CUR_MPS 5 /**< Max packet size, RFC 4340, 14. */
+#endif
+
+/** Estimated worst-case length of a DCCP header including options. */
+#define DCCP_MAX_HEADER 128
+
+/** * Obtain current MPS according to RFC 4340, sec. 14. */
+static int dccp_init_fec(struct sender_client *sc)
+{
+ int mps, ret;
+ socklen_t ml = sizeof(mps);
+ uint32_t mss; /* max slize size */
+
+ /* If call fails, return some sensible minimum value */
+ ret = getsockopt(sc->fd, SOL_DCCP, DCCP_SOCKOPT_GET_CUR_MPS, &mps, &ml);
+ if (ret < 0) {
+ PARA_NOTICE_LOG("can not determine MPS: %s\n", strerror(errno));
+ mps = generic_max_transport_msg_size(sc->fd) - DCCP_MAX_HEADER;
+ }
+ PARA_INFO_LOG("current MPS = %d bytes\n", mps);
+ assert(mps > 0);
+ mss = OPT_UINT32_VAL(DCCP_MAX_SLICE_SIZE);
+ if (mss > 0 && mss <= INT_MAX)
+ mps = PARA_MIN(mps, (int)mss);
+ return mps;
+}
+
+static void dccp_send_fec(struct sender_client *sc, char *buf, size_t len)
+{
+ int ret = xwrite(sc->fd, buf, len);
+
+ if (ret < 0)
+ dccp_shutdown_client(sc);
+}
+
+static void dccp_post_monitor(__a_unused struct sched *s)
+{
+ struct sender_client *sc;
+ struct dccp_fec_client *dfc;
+ int tx_ccid;
+ uint32_t k, n;
+
+ sc = accept_sender_client(dss);
+ if (!sc)
+ return;
+
+ /* If CCID identifiable, present client as <host>#<port>~<ccid> */
+ tx_ccid = dccp_get_tx_ccid(sc->fd);
+ if (tx_ccid != -1) {
+ char *tmp = make_message("%s~%d", sc->name, tx_ccid);
+
+ free(sc->name);
+ sc->name = tmp;
+ }
+ /*
+ * Bypass unused CCID paths: the sender does not receive application data
+ * from the client; by shutting down this unused communication path we can
+ * reduce processing costs a bit. See analogous comment in \ref dccp_recv.c.
+ */
+ if (shutdown(sc->fd, SHUT_RD) < 0) {
+ PARA_WARNING_LOG("%s\n", strerror(errno));
+ shutdown_client(sc, dss);
+ return;
+ }
+ dfc = zalloc(sizeof(*dfc));
+ sc->private_data = dfc;
+ k = OPT_UINT32_VAL(DCCP_DATA_SLICES_PER_GROUP);
+ n = OPT_UINT32_VAL(DCCP_SLICES_PER_GROUP);
+ if (k == 0 || n == 0 || k >= n) {
+ PARA_WARNING_LOG("invalid FEC parameters, using defaults\n");
+ dfc->fcp.data_slices_per_group = 3;
+ dfc->fcp.slices_per_group = 4;
+ } else {
+ dfc->fcp.data_slices_per_group = k;
+ dfc->fcp.slices_per_group = n;
+ }
+ dfc->fcp.init_fec = dccp_init_fec;
+ dfc->fcp.send_fec = dccp_send_fec;
+ dfc->fcp.need_periodic_header = false;
+ dfc->fc = vss_add_fec_client(sc, &dfc->fcp);