add plugin frame for rtp node

using nanomsg as a template

include/villas/nodes/rtp.h

@@ -0,0 +1,80 @@
+/** Node type: rtp
+ *
+ * @file
+ * @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
+ * @copyright 2017-2018, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLASnode
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *********************************************************************************/
+
+/**
+ * @addtogroup rtp rtp node type
+ * @ingroup node
+ * @{
+ */
+
+#pragma once
+
+#include <villas/node.h>
+#include <villas/list.h>
+#include <villas/io.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** The maximum length of a packet which contains stuct rtp. */
+#define RTP_MAX_PACKET_LEN 1500
+
+/* Forward declarations */
+struct format_type;
+
+struct rtp {
+	/*
+	struct {
+		int socket;
+		struct list endpoints;
+	} in, out;
+
+	struct format_type *format;
+	struct io io;
+	*/
+};
+
+/** @see node_type::print */
+char * rtp_print(struct node *n);
+
+/** @see node_type::parse */
+int rtp_parse(struct node *n, json_t *cfg);
+
+/** @see node_type::open */
+int rtp_start(struct node *n);
+
+/** @see node_type::close */
+int rtp_stop(struct node *n);
+
+/** @see node_type::read */
+int rtp_read(struct node *n, struct sample *smps[], unsigned cnt, unsigned *release);
+
+/** @see node_type::write */
+int rtp_write(struct node *n, struct sample *smps[], unsigned cnt, unsigned *release);
+
+#ifdef __cplusplus
+}
+#endif
+
+/** @} */

lib/nodes/rtp.c

@@ -0,0 +1,153 @@
+/** Node type: rtp
+ *
+ * @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
+ * @copyright 2017-2018, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLASnode
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *********************************************************************************/
+
+/* TODO: individual includes instead of wrapper include */
+#include <re/re.h>
+#include <string.h>
+
+#include <villas/plugin.h>
+#include <villas/nodes/rtp.h>
+#include <villas/utils.h>
+#include <villas/format_type.h>
+
+int rtp_reverse(struct node *n)
+{
+	struct rtp *m = (struct rtp *) n->_vd;
+
+	/* TODO */
+
+	return 0;
+}
+
+int rtp_parse(struct node *n, json_t *cfg)
+{
+	int ret;
+	struct rtp *m = (struct rtp *) n->_vd;
+
+	const char *format = "villas.binary";
+
+	json_error_t err;
+
+	/* TODO ret = json_unpack_ex(...); */
+	if (ret)
+		jerror(&err, "Failed to parse configuration of node %s", node_name(n));
+
+	return 0;
+}
+
+char * rtp_print(struct node *n)
+{
+	struct rtp *m = (struct rtp *) n->_vd;
+
+	char *buf = NULL;
+
+	/* TODO */
+
+	return buf;
+}
+
+int rtp_start(struct node *n)
+{
+	int ret;
+	struct rtp *m = (struct rtp *) n->_vd;
+
+	/* TODO */
+
+	return 0;
+}
+
+int rtp_stop(struct node *n)
+{
+	int ret;
+	struct rtp *m = (struct rtp *) n->_vd;
+
+	/* TODO */
+
+	return 0;
+}
+
+int rtp_type_stop()
+{
+	/* TODO */
+
+	return -1;
+}
+
+int rtp_read(struct node *n, struct sample *smps[], unsigned cnt, unsigned *release)
+{
+	struct rtp *m = (struct rtp *) n->_vd;
+	int bytes;
+	char data[RTP_MAX_PACKET_LEN];
+
+    /* TODO */
+
+	return -1;
+}
+
+int rtp_write(struct node *n, struct sample *smps[], unsigned cnt, unsigned *release)
+{
+	int ret;
+	struct rtp *m = (struct rtp *) n->_vd;
+
+	size_t wbytes;
+
+	char data[RTP_MAX_PACKET_LEN];
+
+	/* TODO */
+
+	return cnt;
+}
+
+int rtp_fd(struct node *n)
+{
+	int ret;
+	struct rtp *m = (struct rtp *) n->_vd;
+
+	int fd;
+	size_t len = sizeof(fd);
+
+	/* TODO */
+
+	return fd;
+}
+
+static struct plugin p = {
+	.name		= "rtp",
+	.description	= "real-time transport protocol (libre)",
+	.type		= PLUGIN_TYPE_NODE,
+	.node		= {
+		.vectorize	= 0,
+		.size		= sizeof(struct rtp),
+		.type.stop	= rtp_type_stop,
+		.reverse	= rtp_reverse,
+		.parse		= rtp_parse,
+		.print		= rtp_print,
+		.start		= rtp_start,
+		.stop		= rtp_stop,
+		.read		= rtp_read,
+		.write		= rtp_write,
+		.fd		= rtp_fd
+	}
+};
+
+REGISTER_PLUGIN(&p)
+LIST_INIT_STATIC(&p.node.instances)