static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
					    const struct sctp_association *asoc,
					    const sctp_subtype_t type,
					    void *arg,
					    sctp_cmd_seq_t *commands)
{
	struct sctp_transport *transport = (struct sctp_transport *) arg;
	struct sctp_chunk *reply;

	/* Send a heartbeat to our peer.  */
	reply = sctp_make_heartbeat(asoc, transport);
	if (!reply)
		return SCTP_DISPOSITION_NOMEM;

	/* Set rto_pending indicating that an RTT measurement
	 * is started with this heartbeat chunk.
	 */
	sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
			SCTP_TRANSPORT(transport));

	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
	return SCTP_DISPOSITION_CONSUME;
}

Unknown