VILLASnode/include/villas/kernel/tc_netem.hpp

/* Setup network emulation.
 *
 * We use the firewall mark to apply individual netem qdiscs
 * per node. Every node uses an own BSD socket.
 * By using so SO_MARK socket option (see socket(7))
 * we can classify traffic originating from a node seperately.
 *
 * Author: Steffen Vogel <post@steffenvogel.de>
 * SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
 * SPDX-License-Identifier: Apache-2.0
 */

#pragma once

#include <cstdint>

#include <netlink/route/classifier.h>
#include <netlink/route/qdisc.h>

#include <jansson.h>

namespace villas {
namespace kernel {

// Forward declarations
class Interface;

namespace tc {

typedef uint32_t tc_hdl_t;

/* Parse network emulator (netem) settings.
 *
 * @param json A jansson object containing the settings.
 * @param[out] ne A pointer to a libnl3 qdisc object where setting will be written to.
 * @retval 0 Success. Everything went well.
 * @retval <0 Error. Something went wrong.
 */
int netem_parse(struct rtnl_qdisc **ne, json_t *json);

/* Print network emulator (netem) setting into buffer.
 *
 * @param tc A pointer to the libnl3 qdisc object where settings will be read from.
 * @return A pointer to a string which must be freed() by the caller.
 */
char *netem_print(struct rtnl_qdisc *ne);

/* Add a new network emulator (netem) discipline.
 *
 * @param i[in] The interface to which this qdisc will be added.
 * @param qd[in,out] The libnl3 object of the new prio qdisc.
 * @param handle[in] The handle of the new qdisc.
 * @param parent[in] Make this qdisc a child of this class
 * @retval 0 Success. Everything went well.
 * @retval <0 Error. Something went wrong.
 */
int netem(Interface *i, struct rtnl_qdisc **qd, tc_hdl_t handle,
          tc_hdl_t parent);

int netem_set_delay_distribution(struct rtnl_qdisc *qdisc, json_t *json);

} // namespace tc
} // namespace kernel
} // namespace villas