bacnet_stack/ports/atmega328/apdu.c

/**
 * @brief This module manages the BACnet Application Protocol Data Unit (APDU)
 * @author Steve Karg <skarg@users.sourceforge.net>
 * @date 2007
 * @copyright SPDX-License-Identifier: GPL-2.0-or-later WITH GCC-exception-2.0
 */
#include <stdbool.h>
#include <stdint.h>
#include <stddef.h>
/* BACnet Stack defines - first */
#include "bacnet/bacdef.h"
/* BACnet Stack API */
#include "bacnet/apdu.h"
#include "bacnet/bacdcode.h"
#include "bacnet/basic/services.h"

static uint8_t Local_Network_Priority; /* Fixing test 10.1.2 Network priority */

/**
 * @brief get the local network priority
 * @return local network priority
 */
uint8_t apdu_network_priority(void)
{
    return Local_Network_Priority;
}

/**
 * @brief set the local network priority
 * @param net - local network priority
 */
void apdu_network_priority_set(uint8_t pri)
{
    Local_Network_Priority = pri & 0x03;
}

bool apdu_service_supported(BACNET_SERVICES_SUPPORTED service_supported)
{
    bool status = false;

    if (service_supported == SERVICE_SUPPORTED_READ_PROPERTY) {
        status = true;
    }
    if (service_supported == SERVICE_SUPPORTED_WHO_IS) {
        status = true;
    }
#ifdef WRITE_PROPERTY
    if (service_supported == SERVICE_SUPPORTED_WRITE_PROPERTY) {
        status = true;
    }
#endif

    return status;
}

uint16_t apdu_decode_confirmed_service_request(
    uint8_t *apdu, /* APDU data */
    uint16_t apdu_len,
    BACNET_CONFIRMED_SERVICE_DATA *service_data,
    uint8_t *service_choice,
    uint8_t **service_request,
    uint16_t *service_request_len)
{
    uint16_t len = 0; /* counts where we are in PDU */

    service_data->segmented_message = (apdu[0] & BIT(3)) ? true : false;
    service_data->more_follows = (apdu[0] & BIT(2)) ? true : false;
    service_data->segmented_response_accepted =
        (apdu[0] & BIT(1)) ? true : false;
    service_data->max_segs = decode_max_segs(apdu[1]);
    service_data->max_resp = decode_max_apdu(apdu[1]);
    service_data->invoke_id = apdu[2];
    service_data->priority = apdu_network_priority();
    len = 3;
    if (service_data->segmented_message) {
        service_data->sequence_number = apdu[len++];
        service_data->proposed_window_number = apdu[len++];
    }
    *service_choice = apdu[len++];
    *service_request = &apdu[len];
    *service_request_len = apdu_len - len;

    return len;
}

void apdu_handler(
    BACNET_ADDRESS *src,
    uint8_t *apdu, /* APDU data */
    uint16_t apdu_len)
{
    BACNET_CONFIRMED_SERVICE_DATA service_data = { 0 };
    uint8_t service_choice = 0;
    uint8_t *service_request = NULL;
    uint16_t service_request_len = 0;
    uint16_t len = 0; /* counts where we are in PDU */

    if (apdu) {
        /* PDU Type */
        switch (apdu[0] & 0xF0) {
            case PDU_TYPE_CONFIRMED_SERVICE_REQUEST:
                len = apdu_decode_confirmed_service_request(
                    &apdu[0], /* APDU data */
                    apdu_len, &service_data, &service_choice, &service_request,
                    &service_request_len);
                if (len == 0) {
                    /* service data unable to be decoded - simply drop */
                    break;
                }
                if (service_choice == SERVICE_CONFIRMED_READ_PROPERTY) {
                    handler_read_property(
                        service_request, service_request_len, src,
                        &service_data);
                }
#ifdef WRITE_PROPERTY
                else if (service_choice == SERVICE_CONFIRMED_WRITE_PROPERTY) {
                    handler_write_property(
                        service_request, service_request_len, src,
                        &service_data);
                }
#endif
                else {
                    handler_unrecognized_service(
                        service_request, service_request_len, src,
                        &service_data);
                }
                (void)len;
                break;
            case PDU_TYPE_UNCONFIRMED_SERVICE_REQUEST:
                service_choice = apdu[1];
                service_request = &apdu[2];
                service_request_len = apdu_len - 2;
                if (service_choice == SERVICE_UNCONFIRMED_WHO_IS) {
                    handler_who_is(service_request, service_request_len, src);
                }
                break;
            case PDU_TYPE_SIMPLE_ACK:
            case PDU_TYPE_COMPLEX_ACK:
            case PDU_TYPE_SEGMENT_ACK:
            case PDU_TYPE_ERROR:
            case PDU_TYPE_REJECT:
            case PDU_TYPE_ABORT:
            default:
                break;
        }
    }
    return;
}