vmtimed_vmmci0.c

// Originally from http://www.tedunangst.com/flak/post/vmtimed with minimal modification
#include <sys/param.h>
#include <sys/sysctl.h>
#include <sys/sensors.h>
#include <sys/time.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>

void
error(const char *msg)
{
        syslog(LOG_DAEMON | LOG_ERR, "%s", msg);
        exit(1);
}

int
findvmt0(void)
{
        struct sensordev sdev;
        size_t slen;
        int mib[5];
        int i;

        mib[0] = CTL_HW;
        mib[1] = HW_SENSORS;
        for (i = 0; i < 20; i++) {
                mib[2] = i;
                slen = sizeof(sdev);
                if (sysctl(mib, 3, &sdev, &slen, NULL, 0) == -1)
                        break;
                if (strcmp(sdev.xname, "vmmci0") == 0)
                        return i;
        }
        return -1;
}

void
timeloop(int vmt0)
{
        struct sensor sensor;
        size_t slen;
        int mib[5];
        struct timeval tv;
        double delta;

        mib[0] = CTL_HW;
        mib[1] = HW_SENSORS;
        mib[2] = vmt0;
        mib[3] = SENSOR_TIMEDELTA;
        mib[4] = 0;
        while (1) {
                slen = sizeof(sensor);
                if (sysctl(mib, 5, &sensor, &slen, NULL, 0) == -1)
                        err(1, "sysctl");
                delta = sensor.value / 1000000000.0;
                if (delta < -30 || delta > 60) {
                        syslog(LOG_DAEMON | LOG_NOTICE,
                            "fixing time! %f\n", delta);
                        if (gettimeofday(&tv, NULL) == -1)
                                error("gettimeofday");
                        tv.tv_sec -= delta;
                        if (settimeofday(&tv, NULL) == -1)
                                error("settimeofday");
                }
                sleep(15);
        }
}

int
main(int argc, char **argv)
{
        int vmt0;

        vmt0 = findvmt0();
        if (vmt0 == -1)
                error("can't find vmt0");

        timeloop(vmt0);

}