util.c

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#include <errno.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>

#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/time.h>

#include "log.h"
#include "types.h"

#include "util.h"

// -----  CHANNEL FUNCTIONS  ----- //

int is_current(int index) {
    if (index == I1H_INDEX || index == I1L_INDEX || index == I2H_INDEX ||
        index == I2L_INDEX) {
        return 1;
    } else {
        return 0;
    }
}

int is_low_current(int index) {
    if (index == I1L_INDEX || index == I2L_INDEX) {
        return 1;
    } else {
        return 0;
    }
}

int count_channels(int channels[NUM_CHANNELS]) {
    int c = 0;
    for (int i = 0; i < NUM_CHANNELS; i++) {
        if (channels[i] == CHANNEL_ENABLED) {
            c++;
        }
    }
    return c;
}

int read_status(struct rl_status* status) {

    // map shared memory
    int shm_id =
        shmget(SHMEM_STATUS_KEY, sizeof(struct rl_status), SHMEM_PERMISSIONS);
    if (shm_id == -1) {
        rl_log(ERROR, "In read_status: failed to get shared status memory id; "
                      "%d message: %s",
               errno, strerror(errno));
        return FAILURE;
    }
    struct rl_status* shm_status = (struct rl_status*)shmat(shm_id, NULL, 0);

    if (shm_status == (void*)-1) {
        rl_log(ERROR, "In read_status: failed to map shared status memory; %d "
                      "message: %s",
               errno, strerror(errno));
        return FAILURE;
    }

    // read status
    *status = *shm_status;

    // unmap shared memory
    shmdt(shm_status);

    return SUCCESS;
}

int write_status(struct rl_status* status) {

    // map shared memory
    int shm_id = shmget(SHMEM_STATUS_KEY, sizeof(struct rl_status),
                        IPC_CREAT | SHMEM_PERMISSIONS);
    if (shm_id == -1) {
        rl_log(ERROR, "In write_status: failed to get shared status memory id; "
                      "%d message: %s",
               errno, strerror(errno));
        return FAILURE;
    }

    struct rl_status* shm_status = (struct rl_status*)shmat(shm_id, NULL, 0);
    if (shm_status == (void*)-1) {
        rl_log(ERROR, "In write_status: failed to map shared status memory; %d "
                      "message: %s",
               errno, strerror(errno));
        return FAILURE;
    }

    // write status
    *shm_status = *status;

    // unmap shared memory
    shmdt(shm_status);

    return SUCCESS;
}

int ceil_div(int n, int d) {
    if (n % d == d || n % d == 0) {
        return n / d;
    } else {
        return n / d + 1;
    }
}

// -----  SIGNAL HANDLER  ----- //

void sig_handler(int signo) {

    // signal generated by stop function
    if (signo == SIGQUIT) {
        // stop sampling
        status.sampling = SAMPLING_OFF;
    }

    // Ctrl+C handling
    if (signo == SIGINT) {
        signal(signo, SIG_IGN);
        printf("Stopping RocketLogger ...\n");
        status.sampling = SAMPLING_OFF;
    }
}
// TODO: allow forced Ctrl+C

// -----  FILE READING/WRITING  ----- //

int read_file_value(char filename[]) {
    FILE* fp;
    unsigned int value = 0;
    fp = fopen(filename, "rt");
    if (fp == NULL) {
        rl_log(ERROR, "failed to open file");
        return FAILURE;
    }
    if (fscanf(fp, "%x", &value) <= 0) {
        rl_log(ERROR, "failed to read from file");
        return FAILURE;
    }
    fclose(fp);
    return value;
}

void create_time_stamp(struct time_stamp* timestamp_realtime,
                       struct time_stamp* timestamp_monotonic) {

    struct timespec spec_real;
    struct timespec spec_monotonic;

    // get time stamp of real-time and monotonic clock
    int ret1 = clock_gettime(CLOCK_REALTIME, &spec_real);
    int ret2 = clock_gettime(CLOCK_MONOTONIC_RAW, &spec_monotonic);

    if (ret1 < 0 || ret2 < 0) {
        rl_log(ERROR, "failed to get time");
    }

    // convert to own time stamp
    timestamp_realtime->sec = (int64_t)spec_real.tv_sec;
    timestamp_realtime->nsec = (int64_t)spec_real.tv_nsec;
    timestamp_monotonic->sec = (int64_t)spec_monotonic.tv_sec;
    timestamp_monotonic->nsec = (int64_t)spec_monotonic.tv_nsec;
}

void get_mac_addr(uint8_t mac_address[MAC_ADDRESS_LENGTH]) {
    FILE* fp = fopen(MAC_ADDRESS_FILE, "r");

    unsigned int temp;
    fscanf(fp, "%x", &temp);
    mac_address[0] = (uint8_t)temp;
    for (int i = 1; i < MAC_ADDRESS_LENGTH; i++) {
        fscanf(fp, ":%x", &temp);
        mac_address[i] = (uint8_t)temp;
    }
    fclose(fp);
}