rtcanrecv.c

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <time.h>
#include <errno.h>
#include <getopt.h>

#include <alchemy/task.h>
#include <boilerplate/ancillaries.h>

#include <rtdm/can.h>

static void print_usage(char *prg)
{
    fprintf(stderr,
            "Usage: %s [<can-interface>] [Options]\n"
            "Options:\n"
            " -f  --filter=id:mask[:id:mask]... apply filter\n"
            " -e  --error=mask      receive error messages\n"
            " -t, --timeout=MS      timeout in ms\n"
            " -T, --timestamp       with absolute timestamp\n"
            " -R, --timestamp-rel   with relative timestamp\n"
            " -v, --verbose         be verbose\n"
            " -p, --print=MODULO    print every MODULO message\n"
            " -h, --help            this help\n",
            prg);
}


extern int optind, opterr, optopt;

static int s = -1, verbose = 0, print = 1;
static nanosecs_rel_t timeout = 0, with_timestamp = 0, timestamp_rel = 0;

RT_TASK rt_task_desc;

#define BUF_SIZ 255
#define MAX_FILTER 16

struct sockaddr_can recv_addr;
struct can_filter recv_filter[MAX_FILTER];
static int filter_count = 0;

static int add_filter(u_int32_t id, u_int32_t mask)
{
    if (filter_count >= MAX_FILTER)
        return -1;
    recv_filter[filter_count].can_id = id;
    recv_filter[filter_count].can_mask = mask;
    printf("Filter #%d: id=0x%08x mask=0x%08x\n", filter_count, id, mask);
    filter_count++;
    return 0;
}

static void cleanup(void)
{
    int ret;

    if (verbose)
        printf("Cleaning up...\n");

    if (s >= 0) {
        ret = close(s);
        s = -1;
        if (ret) {
            fprintf(stderr, "close: %s\n", strerror(errno));
        }
        exit(EXIT_SUCCESS);
    }
}

static void cleanup_and_exit(int sig)
{
    if (verbose)
        printf("Signal %d received\n", sig);
    cleanup();
    exit(0);
}

static void rt_task(void)
{
    int i, ret, count = 0;
    struct can_frame frame;
    struct sockaddr_can addr;
    socklen_t addrlen = sizeof(addr);
    struct msghdr msg;
    struct iovec iov;
    nanosecs_abs_t timestamp, timestamp_prev = 0;

    if (with_timestamp) {
        msg.msg_iov = &iov;
        msg.msg_iovlen = 1;
        msg.msg_name = (void *)&addr;
        msg.msg_namelen = sizeof(struct sockaddr_can);
        msg.msg_control = (void *)&timestamp;
        msg.msg_controllen = sizeof(nanosecs_abs_t);
    }

    while (1) {
        if (with_timestamp) {
            iov.iov_base = (void *)&frame;
            iov.iov_len = sizeof(can_frame_t);
            ret = recvmsg(s, &msg, 0);
        } else
            ret = recvfrom(s, (void *)&frame, sizeof(can_frame_t), 0,
                                  (struct sockaddr *)&addr, &addrlen);
        if (ret < 0) {
            switch (errno) {
            case ETIMEDOUT:
                if (verbose)
                    printf("recv: timed out\n");
                continue;
            case EBADF:
                if (verbose)
                    printf("recv: aborted because socket was closed\n");
                break;
            default:
                fprintf(stderr, "recv: %s\n", strerror(errno));
            }
            break;
        }

        if (print && (count % print) == 0) {
            printf("#%d: (%d) ", count, addr.can_ifindex);
            if (with_timestamp && msg.msg_controllen) {
                if (timestamp_rel) {
                printf("%lldns ", (long long)(timestamp - timestamp_prev));
                    timestamp_prev = timestamp;
                } else
                    printf("%lldns ", (long long)timestamp);
            }
            if (frame.can_id & CAN_ERR_FLAG)
                printf("!0x%08x!", frame.can_id & CAN_ERR_MASK);
            else if (frame.can_id & CAN_EFF_FLAG)
                printf("<0x%08x>", frame.can_id & CAN_EFF_MASK);
            else
                printf("<0x%03x>", frame.can_id & CAN_SFF_MASK);

            printf(" [%d]", frame.can_dlc);
            if (!(frame.can_id & CAN_RTR_FLAG))
                for (i = 0; i < frame.can_dlc; i++) {
                    printf(" %02x", frame.data[i]);
                }
            if (frame.can_id & CAN_ERR_FLAG) {
                printf(" ERROR ");
                if (frame.can_id & CAN_ERR_BUSOFF)
                    printf("bus-off");
                if (frame.can_id & CAN_ERR_CRTL)
                    printf("controller problem");
            } else if (frame.can_id & CAN_RTR_FLAG)
                printf(" remote request");
            printf("\n");
        }
        count++;
    }
}

int main(int argc, char **argv)
{
    int opt, ret;
    u_int32_t id, mask;
    u_int32_t err_mask = 0;
    struct can_ifreq ifr;
    char *ptr;
    char name[32];

    struct option long_options[] = {
        { "help", no_argument, 0, 'h' },
        { "verbose", no_argument, 0, 'v'},
        { "filter", required_argument, 0, 'f'},
        { "error", required_argument, 0, 'e'},
        { "timeout", required_argument, 0, 't'},
        { "timestamp", no_argument, 0, 'T'},
        { "timestamp-rel", no_argument, 0, 'R'},
        { 0, 0, 0, 0},
    };

    signal(SIGTERM, cleanup_and_exit);
    signal(SIGINT, cleanup_and_exit);

    while ((opt = getopt_long(argc, argv, "hve:f:t:p:RT",
                              long_options, NULL)) != -1) {
        switch (opt) {
        case 'h':
            print_usage(argv[0]);
            exit(0);

        case 'p':
            print = strtoul(optarg, NULL, 0);
            break;

        case 'v':
            verbose = 1;
            break;

        case 'e':
            err_mask = strtoul(optarg, NULL, 0);
            break;

        case 'f':
            ptr = optarg;
            while (1) {
                id = strtoul(ptr, NULL, 0);
                ptr = strchr(ptr, ':');
                if (!ptr) {
                    fprintf(stderr, "filter must be applied in the form id:mask[:id:mask]...\n");
                    exit(1);
                }
                ptr++;
                mask = strtoul(ptr, NULL, 0);
                ptr = strchr(ptr, ':');
                add_filter(id, mask);
                if (!ptr)
                    break;
                ptr++;
            }
            break;

        case 't':
            timeout = (nanosecs_rel_t)strtoul(optarg, NULL, 0) * 1000000;
            break;

        case 'R':
            timestamp_rel = 1;
        case 'T':
            with_timestamp = 1;
            break;

        default:
            fprintf(stderr, "Unknown option %c\n", opt);
            break;
        }
    }

    ret = socket(PF_CAN, SOCK_RAW, CAN_RAW);
    if (ret < 0) {
        fprintf(stderr, "socket: %s\n", strerror(errno));
        return -1;
    }
    s = ret;

    if (argv[optind] == NULL) {
        if (verbose)
            printf("interface all\n");

        ifr.ifr_ifindex = 0;
    } else {
        if (verbose)
            printf("interface %s\n", argv[optind]);

        namecpy(ifr.ifr_name, argv[optind]);
        if (verbose)
            printf("s=%d, ifr_name=%s\n", s, ifr.ifr_name);

        ret = ioctl(s, SIOCGIFINDEX, &ifr);
        if (ret < 0) {
            fprintf(stderr, "ioctl GET_IFINDEX: %s\n", strerror(errno));
            goto failure;
        }
    }

    if (err_mask) {
        ret = setsockopt(s, SOL_CAN_RAW, CAN_RAW_ERR_FILTER,
                                &err_mask, sizeof(err_mask));
        if (ret < 0) {
            fprintf(stderr, "setsockopt: %s\n", strerror(errno));
            goto failure;
        }
        if (verbose)
            printf("Using err_mask=%#x\n", err_mask);
    }

    if (filter_count) {
        ret = setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER,
                                &recv_filter, filter_count *
                                sizeof(struct can_filter));
        if (ret < 0) {
            fprintf(stderr, "setsockopt: %s\n", strerror(errno));
            goto failure;
        }
    }

    recv_addr.can_family = AF_CAN;
    recv_addr.can_ifindex = ifr.ifr_ifindex;
    ret = bind(s, (struct sockaddr *)&recv_addr,
                      sizeof(struct sockaddr_can));
    if (ret < 0) {
        fprintf(stderr, "bind: %s\n", strerror(errno));
        goto failure;
    }

    if (timeout) {
        if (verbose)
            printf("Timeout: %lld ns\n", (long long)timeout);
        ret = ioctl(s, RTCAN_RTIOC_RCV_TIMEOUT, &timeout);
        if (ret) {
            fprintf(stderr, "ioctl RCV_TIMEOUT: %s\n", strerror(errno));
            goto failure;
        }
    }

    if (with_timestamp) {
        ret = ioctl(s, RTCAN_RTIOC_TAKE_TIMESTAMP, RTCAN_TAKE_TIMESTAMPS);
        if (ret) {
            fprintf(stderr, "ioctl TAKE_TIMESTAMP: %s\n", strerror(errno));
            goto failure;
        }
    }

    snprintf(name, sizeof(name), "rtcanrecv-%d", getpid());
    ret = rt_task_shadow(&rt_task_desc, name, 0, 0);
    if (ret) {
        fprintf(stderr, "rt_task_shadow: %s\n", strerror(-ret));
        goto failure;
    }

    rt_task();
    /* never returns */

 failure:
    cleanup();
    return -1;
}