j1939_bam_no_errorqueue.c

#include <stdio.h>
#include <sys/socket.h>
#include <linux/can.h>
#include <linux/can/j1939.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/kernel.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <time.h>

#define CAN_DEV "can0"
#define NS_IN_MS 1000000
#define SLEEP_TIME_MS 50
#define SLEEP_TIME_NS (SLEEP_TIME_MS * NS_IN_MS)
#define SLEEP_TIME_S 0

int jt_create_sock()
{
    int ret;
    int err_queue = 1;
    int sock;
    unsigned int sock_opt;
        
    sock = socket(PF_CAN, SOCK_DGRAM, CAN_J1939);
    if (sock < 0) {
        printf("Error creating socket %m\n");
        return ret;
    }

    ret = setsockopt(sock, SOL_SOCKET, SO_BROADCAST,
             &err_queue, sizeof(err_queue));
    if (ret < 0) {
        printf("Error setting broadcast opt %m\n");
        return ret;
    }

    return sock;
}

int jt_bind_socket(int sock, const char* if_name,  u_int64_t name, u_int32_t pgn, u_int8_t addr)
{
    int ret; 
    struct ifreq ifr = {};
    struct sockaddr_can sc = {};

    strcpy(ifr.ifr_name, if_name);
    ret = ioctl(sock, SIOCGIFINDEX, &ifr);

    if(ret < 0)
    {
        printf("Error SIOCGIFINDEX ioctl %m\n");
        return ret;
    }

    sc.can_family = AF_CAN;
    sc.can_ifindex = ifr.ifr_ifindex;
    sc.can_addr.j1939.addr = addr;
    sc.can_addr.j1939.name = name;
    sc.can_addr.j1939.pgn = pgn;

    ret = bind(sock, (struct sockaddr*) &sc, sizeof(sc));

    if(ret < 0)
    {
        printf("Error binding %m\n");
        return ret;
    }

    return 0;
}

int main()
{
    int sock = jt_create_sock();
    int ret;
    u_int8_t data[] = {0x10, 0x3F, 0x46, 0x00, 0x02, 0x22, 0xAB, 0x00, 0x02, 0x03, 0x10, 0xF7, 0xEC, 0x03, 0x6F, 0x00, 0x12,
                        0x7E, 0x4B, 0xF7, 0xF2, 0x7E, 0x1A, 0xF7, 0xE4, 0x7E, 0x1A, 0xF7, 0xEB, 0x7E, 0x1A, 0xF7, 0xE6, 0x7E};
    const struct sockaddr_can saddr = {
        .can_family = AF_CAN,
        .can_addr.j1939 = {
                .name = J1939_NO_NAME,
                .pgn = 0xFECA,
                .addr = 0xFF,
        },
    };

    const struct timespec sleep_time = {
        .tv_sec = 0,
        .tv_nsec = SLEEP_TIME_NS
    };

    if(sock < 0)
    {
        return -1;
    }

    ret = jt_bind_socket(sock, CAN_DEV, J1939_NO_NAME, J1939_NO_PGN, 0x27);

    if(ret < 0)
    {
        return -1;
    }

    printf("Make sure there is no other can device on the bus\n");
    printf("Press any button to continue\n");

    getc(stdin);
    printf("Sending a couple of messages\n");
    for(int i = 0; i < 50; i++)
    {
        int res;

        printf("Sending sn %d\n", i);
        res= sendto(sock, data, sizeof(data), 0, (const struct sockaddr *) &saddr, sizeof(saddr));
        if(res == -1)
        {
            printf("Got error: %m. continuing...\n");
        }
        clock_nanosleep(CLOCK_REALTIME, 0, &sleep_time, NULL);
    }
    printf("Switch on another device on the bus\n");
    printf("Press any button\n");
    getc(stdin);
    printf("Sending a couple of messages\n");
    for(int i = 0; i < 10; i++)
    {
        int res = sendto(sock, data, sizeof(data), 0, (const struct sockaddr *) &saddr, sizeof(saddr));
        if(res == -1)
            printf("%m\n");
        
        clock_nanosleep(CLOCK_REALTIME, 0, &sleep_time, NULL);
    }

    printf("Now closing socket....\n");
    close(sock);
}