mavlink_parameters.cpp

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/**
 * @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 if (!((param_type(param) == PARAM_TYPE_INT32 && set.param_type == MAV_PARAM_TYPE_INT32) ||
                         (param_type(param) == PARAM_TYPE_FLOAT && set.param_type == MAV_PARAM_TYPE_REAL32))) {
                    char buf[MAVLINK_MSG_STATUSTEXT_FIELD_TEXT_LEN];
                    sprintf(buf, "[pm] param types mismatch 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() == Protocol::SERIAL && !_mavlink->is_usb_uart()) {
        max_num_to_send = 3;

    } else {
        // speed up parameter loading via UDP 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) {
        /* 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;
        }
    }

    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;
    }
}