text: /****************************************************************************
   *
   *   Copyright (c) 2015-2018 PX4 Development Team. All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   * 3. Neither the name PX4 nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   ****************************************************************************/
  
  /**
   * @file mavlink_parameters.cpp
   * Mavlink parameters manager implementation.
   *
   * @author Anton Babushkin <anton.babushkin@me.com>
   * @author Lorenz Meier <lorenz@px4.io>
   * @author Beat Kueng <beat@px4.io>
   */
  
  #include <stdio.h>
  
  #include "mavlink_parameters.h"
  #include "mavlink_main.h"
  
  MavlinkParametersManager::MavlinkParametersManager(Mavlink *mavlink) :
  	_mavlink(mavlink)
  {
  }
  
  unsigned
  MavlinkParametersManager::get_size()
  {
  	return MAVLINK_MSG_ID_PARAM_VALUE_LEN + MAVLINK_NUM_NON_PAYLOAD_BYTES;
  }
  
  void
  MavlinkParametersManager::handle_message(const mavlink_message_t *msg)
  {
  	switch (msg->msgid) {
  	case MAVLINK_MSG_ID_PARAM_REQUEST_LIST: {
  			/* request all parameters */
  			mavlink_param_request_list_t req_list;
  			mavlink_msg_param_request_list_decode(msg, &req_list);
  
  			if (req_list.target_system == mavlink_system.sysid &&
  			    (req_list.target_component == mavlink_system.compid || req_list.target_component == MAV_COMP_ID_ALL)) {
  				if (_send_all_index < 0) {
  					_send_all_index = PARAM_HASH;
  
  				} else {
  					/* a restart should skip the hash check on the ground */
  					_send_all_index = 0;
  				}
  			}
  
  			if (req_list.target_system == mavlink_system.sysid && req_list.target_component < 127 &&
  			    (req_list.target_component != mavlink_system.compid || req_list.target_component == MAV_COMP_ID_ALL)) {
  				// publish list request to UAVCAN driver via uORB.
  				uavcan_parameter_request_s req;
  				req.message_type = msg->msgid;
  				req.node_id = req_list.target_component;
  				req.param_index = 0;
  
  				_uavcan_parameter_request_pub.publish(req);
  			}
  
  			break;
  		}
  
  	case MAVLINK_MSG_ID_PARAM_SET: {
  			/* set parameter */
  			mavlink_param_set_t set;
  			mavlink_msg_param_set_decode(msg, &set);
  
  			if (set.target_system == mavlink_system.sysid &&
  			    (set.target_component == mavlink_system.compid || set.target_component == MAV_COMP_ID_ALL)) {
  
  				/* local name buffer to enforce null-terminated string */
  				char name[MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN + 1];
  				strncpy(name, set.param_id, MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN);
  				/* enforce null termination */
  				name[MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN] = '\0';
  
  				/* Whatever the value is, we're being told to stop sending */
  				if (strncmp(name, "_HASH_CHECK", sizeof(name)) == 0) {
  
  					if (_mavlink->hash_check_enabled()) {
  						_send_all_index = -1;
  					}
  
  					/* No other action taken, return */
  					return;
  				}
  
  				/* attempt to find parameter, set and send it */
  				param_t param = param_find_no_notification(name);
  
  				if (param == PARAM_INVALID) {
  					char buf[MAVLINK_MSG_STATUSTEXT_FIELD_TEXT_LEN];
  					sprintf(buf, "[pm] unknown param: %s", name);
  					_mavlink->send_statustext_info(buf);
  
  				} else {
  					// According to the mavlink spec we should always acknowledge a write operation.
  					param_set(param, &(set.param_value));
  					send_param(param);
  				}
  			}
  
  			if (set.target_system == mavlink_system.sysid && set.target_component < 127 &&
  			    (set.target_component != mavlink_system.compid || set.target_component == MAV_COMP_ID_ALL)) {
  				// publish set request to UAVCAN driver via uORB.
  				uavcan_parameter_request_s req;
  				req.message_type = msg->msgid;
  				req.node_id = set.target_component;
  				req.param_index = -1;
  				strncpy(req.param_id, set.param_id, MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN + 1);
  				req.param_id[MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN] = '\0';
  
  				if (set.param_type == MAV_PARAM_TYPE_REAL32) {
  					req.param_type = MAV_PARAM_TYPE_REAL32;
  					req.real_value = set.param_value;
  
  				} else {
  					int32_t val;
  					memcpy(&val, &set.param_value, sizeof(int32_t));
  					req.param_type = MAV_PARAM_TYPE_INT64;
  					req.int_value = val;
  				}
  
  				_uavcan_parameter_request_pub.publish(req);
  			}
  
  			break;
  		}
  
  	case MAVLINK_MSG_ID_PARAM_REQUEST_READ: {
  			/* request one parameter */
  			mavlink_param_request_read_t req_read;
  			mavlink_msg_param_request_read_decode(msg, &req_read);
  
  			if (req_read.target_system == mavlink_system.sysid &&
  			    (req_read.target_component == mavlink_system.compid || req_read.target_component == MAV_COMP_ID_ALL)) {
  
  				/* when no index is given, loop through string ids and compare them */
  				if (req_read.param_index < 0) {
  					/* XXX: I left this in so older versions of QGC wouldn't break */
  					if (strncmp(req_read.param_id, HASH_PARAM, MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN) == 0) {
  						/* return hash check for cached params */
  						uint32_t hash = param_hash_check();
  
  						/* build the one-off response message */
  						mavlink_param_value_t param_value;
  						param_value.param_count = param_count_used();
  						param_value.param_index = -1;
  						strncpy(param_value.param_id, HASH_PARAM, MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN);
  						param_value.param_type = MAV_PARAM_TYPE_UINT32;
  						memcpy(&param_value.param_value, &hash, sizeof(hash));
  						mavlink_msg_param_value_send_struct(_mavlink->get_channel(), &param_value);
  
  					} else {
  						/* local name buffer to enforce null-terminated string */
  						char name[MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN + 1];
  						strncpy(name, req_read.param_id, MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN);
  						/* enforce null termination */
  						name[MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN] = '\0';
  						/* attempt to find parameter and send it */
  						send_param(param_find_no_notification(name));
  					}
  
  				} else {
  					/* when index is >= 0, send this parameter again */
  					int ret = send_param(param_for_used_index(req_read.param_index));
  
  					if (ret == 1) {
  						char buf[MAVLINK_MSG_STATUSTEXT_FIELD_TEXT_LEN];
  						sprintf(buf, "[pm] unknown param ID: %u", req_read.param_index);
  						_mavlink->send_statustext_info(buf);
  
  					} else if (ret == 2) {
  						char buf[MAVLINK_MSG_STATUSTEXT_FIELD_TEXT_LEN];
  						sprintf(buf, "[pm] failed loading param from storage ID: %u", req_read.param_index);
  						_mavlink->send_statustext_info(buf);
  					}
  				}
  			}
  
  			if (req_read.target_system == mavlink_system.sysid && req_read.target_component < 127 &&
  			    (req_read.target_component != mavlink_system.compid || req_read.target_component == MAV_COMP_ID_ALL)) {
  				// publish set request to UAVCAN driver via uORB.
  				uavcan_parameter_request_s req = {};
  				req.timestamp = hrt_absolute_time();
  				req.message_type = msg->msgid;
  				req.node_id = req_read.target_component;
  				req.param_index = req_read.param_index;
  				strncpy(req.param_id, req_read.param_id, MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN + 1);
  				req.param_id[MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN] = '\0';
  
  				// Enque the request and forward the first to the uavcan node
  				enque_uavcan_request(&req);
  				request_next_uavcan_parameter();
  			}
  
  			break;
  		}
  
  	case MAVLINK_MSG_ID_PARAM_MAP_RC: {
  			/* map a rc channel to a parameter */
  			mavlink_param_map_rc_t map_rc;
  			mavlink_msg_param_map_rc_decode(msg, &map_rc);
  
  			if (map_rc.target_system == mavlink_system.sysid &&
  			    (map_rc.target_component == mavlink_system.compid ||
  			     map_rc.target_component == MAV_COMP_ID_ALL)) {
  
  				/* Copy values from msg to uorb using the parameter_rc_channel_index as index */
  				size_t i = map_rc.parameter_rc_channel_index;
  				_rc_param_map.param_index[i] = map_rc.param_index;
  				strncpy(&(_rc_param_map.param_id[i * (rc_parameter_map_s::PARAM_ID_LEN + 1)]), map_rc.param_id,
  					MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN);
  				/* enforce null termination */
  				_rc_param_map.param_id[i * (rc_parameter_map_s::PARAM_ID_LEN + 1) + rc_parameter_map_s::PARAM_ID_LEN] = '\0';
  				_rc_param_map.scale[i] = map_rc.scale;
  				_rc_param_map.value0[i] = map_rc.param_value0;
  				_rc_param_map.value_min[i] = map_rc.param_value_min;
  				_rc_param_map.value_max[i] = map_rc.param_value_max;
  
  				if (map_rc.param_index == -2) { // -2 means unset map
  					_rc_param_map.valid[i] = false;
  
  				} else {
  					_rc_param_map.valid[i] = true;
  				}
  
  				_rc_param_map.timestamp = hrt_absolute_time();
  				_rc_param_map_pub.publish(_rc_param_map);
  			}
  
  			break;
  		}
  
  	default:
  		break;
  	}
  }
  
  void
  MavlinkParametersManager::send(const hrt_abstime t)
  {
  	int max_num_to_send;
  
  	if (_mavlink->get_protocol() == SERIAL && !_mavlink->is_usb_uart()) {
  		max_num_to_send = 3;
  
  	} else {
  		// speed up parameter loading via UDP, TCP or USB: try to send 20 at once
  		max_num_to_send = 20;
  	}
  
  	int i = 0;
  
  	// Send while burst is not exceeded, we still have buffer space and still something to send
  	while ((i++ < max_num_to_send) && (_mavlink->get_free_tx_buf() >= get_size()) && send_params());
  }
  
  bool
  MavlinkParametersManager::send_params()
  {
  	if (send_uavcan()) {
  		return true;
  
  	} else if (send_one()) {
  		return true;
  
  	} else if (send_untransmitted()) {
  		return true;
  
  	} else {
  		return false;
  	}
  }
  
  bool
  MavlinkParametersManager::send_untransmitted()
  {
  	bool sent_one = false;
  
  	if (_mavlink_parameter_sub.updated()) {
  		// Clear the ready flag
  		parameter_update_s value;
  		_mavlink_parameter_sub.update(&value);
  
  		// Schedule an update if not already the case
  		if (_param_update_time == 0) {
  			_param_update_time = value.timestamp;
  			_param_update_index = 0;
  		}
  	}
  
  	if ((_param_update_time != 0) && ((_param_update_time + 5 * 1000) < hrt_absolute_time())) {
  
  		param_t param = 0;
  
  		// send out all changed values
  		do {
  			// skip over all parameters which are not invalid and not used
  			do {
  				param = param_for_index(_param_update_index);
  				++_param_update_index;
  			} while (param != PARAM_INVALID && !param_used(param));
  
  			// send parameters which are untransmitted while there is
  			// space in the TX buffer
  			if ((param != PARAM_INVALID) && param_value_unsaved(param)) {
  				int ret = send_param(param);
  				char buf[100];
  				strncpy(&buf[0], param_name(param), MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN);
  				sent_one = true;
  
  				if (ret != PX4_OK) {
  					break;
  				}
  			}
  		} while ((_mavlink->get_free_tx_buf() >= get_size()) && (_param_update_index < (int) param_count()));
  
  		// Flag work as done once all params have been sent
  		if (_param_update_index >= (int) param_count()) {
  			_param_update_time = 0;
  		}
  	}
  
  	return sent_one;
  }
  
  bool
  MavlinkParametersManager::send_uavcan()
  {
  	/* Send parameter values received from the UAVCAN topic */
  	uavcan_parameter_value_s value{};
  
  	if (_uavcan_parameter_value_sub.update(&value)) {
  
  		// Check if we received a matching parameter, drop it from the list and request the next
  		if ((_uavcan_open_request_list != nullptr)
  		    && (value.param_index == _uavcan_open_request_list->req.param_index)
  		    && (value.node_id == _uavcan_open_request_list->req.node_id)) {
  
  			dequeue_uavcan_request();
  			request_next_uavcan_parameter();
  		}
  
  		mavlink_param_value_t msg{};
  		msg.param_count = value.param_count;
  		msg.param_index = value.param_index;
  #if defined(__GNUC__) && __GNUC__ >= 8
  #pragma GCC diagnostic ignored "-Wstringop-truncation"
  #endif
  		/*
  		 * coverity[buffer_size_warning : FALSE]
  		 *
  		 * The MAVLink spec does not require the string to be NUL-terminated if it
  		 * has length 16. In this case the receiving end needs to terminate it
  		 * when copying it.
  		 */
  		strncpy(msg.param_id, value.param_id, MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN);
  #if defined(__GNUC__) && __GNUC__ >= 8
  #pragma GCC diagnostic pop
  #endif
  
  		if (value.param_type == MAV_PARAM_TYPE_REAL32) {
  			msg.param_type = MAVLINK_TYPE_FLOAT;
  			msg.param_value = value.real_value;
  
  		} else {
  			int32_t val = (int32_t)value.int_value;
  			memcpy(&msg.param_value, &val, sizeof(int32_t));
  			msg.param_type = MAVLINK_TYPE_INT32_T;
  		}
  
  		// Re-pack the message with the UAVCAN node ID
  		mavlink_message_t mavlink_packet{};
  		mavlink_msg_param_value_encode_chan(mavlink_system.sysid, value.node_id, _mavlink->get_channel(), &mavlink_packet,
  						    &msg);
  		_mavlink_resend_uart(_mavlink->get_channel(), &mavlink_packet);
  
  		return true;
  	}
  
  	return false;
  }
  
  bool
  MavlinkParametersManager::send_one()
  {
  	if (_send_all_index >= 0 && _mavlink->boot_complete()) {
  		/* send all parameters if requested, but only after the system has booted */
  
  		/* The first thing we send is a hash of all values for the ground
  		 * station to try and quickly load a cached copy of our params
  		 */
  		if (_send_all_index == PARAM_HASH) {
  			/* return hash check for cached params */
  			uint32_t hash = param_hash_check();
  
  			/* build the one-off response message */
  			mavlink_param_value_t msg;
  			msg.param_count = param_count_used();
  			msg.param_index = -1;
  			strncpy(msg.param_id, HASH_PARAM, MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN);
  			msg.param_type = MAV_PARAM_TYPE_UINT32;
  			memcpy(&msg.param_value, &hash, sizeof(hash));
  			mavlink_msg_param_value_send_struct(_mavlink->get_channel(), &msg);
  
  			/* after this we should start sending all params */
  			_send_all_index = 0;
  
  			/* No further action, return now */
  			return true;
  		}
  
  		/* look for the first parameter which is used */
  		param_t p;
  
  		do {
  			/* walk through all parameters, including unused ones */
  			p = param_for_index(_send_all_index);
  			_send_all_index++;
  		} while (p != PARAM_INVALID && !param_used(p));
  
  		if (p != PARAM_INVALID) {
  			send_param(p);
  		}
  
  		if ((p == PARAM_INVALID) || (_send_all_index >= (int) param_count())) {
  			_send_all_index = -1;
  			return false;
  
  		} else {
  			return true;
  		}
  
  	} else if (_send_all_index == PARAM_HASH && hrt_absolute_time() > 20 * 1000 * 1000) {
  		/* the boot did not seem to ever complete, warn user and set boot complete */
  		_mavlink->send_statustext_critical("WARNING: SYSTEM BOOT INCOMPLETE. CHECK CONFIG.");
  		_mavlink->set_boot_complete();
  	}
  
  	return false;
  }
  
  int
  MavlinkParametersManager::send_param(param_t param, int component_id)
  {
  	if (param == PARAM_INVALID) {
  		return 1;
  	}
  
  	/* no free TX buf to send this param */
  	if (_mavlink->get_free_tx_buf() < MAVLINK_MSG_ID_PARAM_VALUE_LEN) {
  		return 1;
  	}
  
  	mavlink_param_value_t msg;
  
  	/*
  	 * get param value, since MAVLink encodes float and int params in the same
  	 * space during transmission, copy param onto float val_buf
  	 */
  	float param_value{};
  
  	if (param_get(param, &param_value) != OK) {
  		return 2;
  	}
  
  	msg.param_value = param_value;
  
  	msg.param_count = param_count_used();
  	msg.param_index = param_get_used_index(param);
  
  #if defined(__GNUC__) && __GNUC__ >= 8
  #pragma GCC diagnostic push
  #pragma GCC diagnostic ignored "-Wstringop-truncation"
  #endif
  	/*
  	 * coverity[buffer_size_warning : FALSE]
  	 *
  	 * The MAVLink spec does not require the string to be NUL-terminated if it
  	 * has length 16. In this case the receiving end needs to terminate it
  	 * when copying it.
  	 */
  	strncpy(msg.param_id, param_name(param), MAVLINK_MSG_PARAM_VALUE_FIELD_PARAM_ID_LEN);
  #if defined(__GNUC__) && __GNUC__ >= 8
  #pragma GCC diagnostic pop
  #endif
  
  	/* query parameter type */
  	param_type_t type = param_type(param);
  
  	/*
  	 * Map onboard parameter type to MAVLink type,
  	 * endianess matches (both little endian)
  	 */
  	if (type == PARAM_TYPE_INT32) {
  		msg.param_type = MAVLINK_TYPE_INT32_T;
  
  	} else if (type == PARAM_TYPE_FLOAT) {
  		msg.param_type = MAVLINK_TYPE_FLOAT;
  
  	} else {
  		msg.param_type = MAVLINK_TYPE_FLOAT;
  	}
  
  	/* default component ID */
  	if (component_id < 0) {
  		mavlink_msg_param_value_send_struct(_mavlink->get_channel(), &msg);
  
  	} else {
  		// Re-pack the message with a different component ID
  		mavlink_message_t mavlink_packet;
  		mavlink_msg_param_value_encode_chan(mavlink_system.sysid, component_id, _mavlink->get_channel(), &mavlink_packet, &msg);
  		_mavlink_resend_uart(_mavlink->get_channel(), &mavlink_packet);
  	}
  
  	return 0;
  }
  
  void MavlinkParametersManager::request_next_uavcan_parameter()
  {
  	// Request a parameter if we are not already waiting on a response and if the list is not empty
  	if (!_uavcan_waiting_for_request_response && _uavcan_open_request_list != nullptr) {
  		uavcan_parameter_request_s req = _uavcan_open_request_list->req;
  
  		_uavcan_parameter_request_pub.publish(req);
  
  		_uavcan_waiting_for_request_response = true;
  	}
  }
  
  void MavlinkParametersManager::enque_uavcan_request(uavcan_parameter_request_s *req)
  {
  	// We store at max 10 requests to keep memory consumption low.
  	// Dropped requests will be repeated by the ground station
  	if (_uavcan_queued_request_items >= 10) {
  		return;
  	}
  
  	_uavcan_open_request_list_item *new_reqest = new _uavcan_open_request_list_item;
  	new_reqest->req = *req;
  	new_reqest->next = nullptr;
  
  	_uavcan_open_request_list_item *item = _uavcan_open_request_list;
  	++_uavcan_queued_request_items;
  
  	if (item == nullptr) {
  		// Add the first item to the list
  		_uavcan_open_request_list = new_reqest;
  
  	} else {
  		// Find the last item and add the new request at the end
  		while (item->next != nullptr) {
  			item = item->next;
  		}
  
  		item->next = new_reqest;
  	}
  }
  
  void MavlinkParametersManager::dequeue_uavcan_request()
  {
  	if (_uavcan_open_request_list != nullptr) {
  		// Drop the first item in the list and free the used memory
  		_uavcan_open_request_list_item *first = _uavcan_open_request_list;
  		_uavcan_open_request_list = first->next;
  		--_uavcan_queued_request_items;
  		delete first;
  		_uavcan_waiting_for_request_response = false;
  	}
  }
  