j1939_logger.c

/*
 *                   Copyright 2026 by KVASER AB, SWEDEN
 *
 *                        WWW: https://www.kvaser.com
 *
 * This software is furnished under a license and may be used and copied
 * only in accordance with the terms of such license.
 *
 */
 
#include <kvj1939lib.h>
 
#include <inttypes.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
// Callback for received messages
void rx_callback(J1939ChannelHandle channel, void* context, J1939Identifier id,
                 uint64_t timestamp, const uint8_t* payload,
                 uint32_t payload_length, bool error)
{
    if (error) {
        printf("Error frame: timestamp: %" PRIu64 "\n", timestamp);
    } else {
        printf("PGN: %u, SA: %u, DA: %u, length: %u, timestamp: %" PRIu64
               ", data: ",
               id.pgn, id.src_addr, id.dest_addr, payload_length, timestamp);
        for (uint32_t i = 0; i < payload_length; i++) {
            printf("%02X ", payload[i]);
        }
        printf("\n");
    }
}
 
// Prints out the help message for the command line options
void print_help()
{
    printf(
        "Usage: j1939_logger [options]\n"
        "Options:\n"
        "  --channel <channel>, -c <channel>     Set CAN channel (default: 0)\n"
        "  --bit-rate <bit_rate>, -b <bit_rate>  Set CAN bit rate (default: "
        "250000)\n"
        "  --help, -h                            Show this help message\n");
}
 
// Main function demonstrating the usage of the Kvaser J1939 library to log
// J1939 traffic. The program will print all received messages, with exception
// of directed multi frame messages.
//
// This function creates a J1939 channel, registers callback, opens the channel,
// waits for received messages, and cleans up resources.
int main(int argc, char* argv[])
{
    unsigned int channel_no = 0;
    unsigned int bit_rate = 250000;
 
    // Parse command line arguments
    for (int i = 1; i < argc; ++i) {
        if ((strcmp(argv[i], "--channel") == 0 || strcmp(argv[i], "-c") == 0)
            && i + 1 < argc) {
            channel_no = (unsigned int)strtoul(argv[++i], NULL, 0);
        } else if ((strcmp(argv[i], "--bit-rate") == 0
                    || strcmp(argv[i], "-b") == 0)
                   && i + 1 < argc) {
            bit_rate = (unsigned int)strtoul(argv[++i], NULL, 0);
        } else if (strcmp(argv[i], "--help") == 0
                   || strcmp(argv[i], "-h") == 0) {
            print_help();
            return 0;
        }
    }
 
    // Create a J1939 channel
    J1939ChannelParams create_params = { .channel = channel_no,
                                         .support_virtual = true,
                                         .bit_rate = bit_rate };
    J1939ChannelResult create_result = j1939_create_channel(create_params);
    if (create_result.result != J1939_STATUS_OK) {
        fprintf(stderr, "Failed to create J1939 channel!\n");
        return 1;
    }
    J1939ChannelHandle j1939_handle = create_result.hnd;
 
    // Register callbacks
    if (j1939_register_callbacks(j1939_handle, NULL, rx_callback, NULL, NULL)
        != J1939_STATUS_OK) {
        fprintf(stderr, "Failed to register callbacks!\n");
        j1939_destroy_channel(j1939_handle);
        return 1;
    }
 
    // Open the channel
    if (j1939_open_channel(j1939_handle) != J1939_STATUS_OK) {
        fprintf(stderr, "Failed to open J1939 channel!\n");
        j1939_destroy_channel(j1939_handle);
        return 1;
    }
 
    // Wait for callbacks to be triggered
    printf("Logging traffic on channel %u. Press Enter to exit...\n",
           channel_no);
    getchar();
 
    // Close the channel
    if (j1939_close_channel(j1939_handle) != J1939_STATUS_OK) {
        fprintf(stderr, "Failed to close J1939 channel!\n");
    } else {
        printf("J1939 channel closed successfully!\n");
    }
 
    // Destroy the channel
    j1939_destroy_channel(j1939_handle);
 
    return 0;
}