void
ntpd_settime(double d)
{
struct timeval tv, curtime;
char buf[80];
time_t tval;
if (gettimeofday(&curtime, NULL) == -1) {
log_warn("gettimeofday");
return;
}
d_to_tv(d, &tv);
curtime.tv_usec += tv.tv_usec + 1000000;
curtime.tv_sec += tv.tv_sec - 1 + (curtime.tv_usec / 1000000);
curtime.tv_usec %= 1000000;
if (settimeofday(&curtime, NULL) == -1) {
log_warn("settimeofday");
return;
}
tval = curtime.tv_sec;
strftime(buf, sizeof(buf), "%a %b %e %H:%M:%S %Z %Y",
localtime(&tval));
log_info("set local clock to %s (offset %fs)", buf, d);
}
void
show_status_msg(struct imsg *imsg)
{
struct ctl_show_status *cstatus;
double clock_offset;
struct timeval tv;
if (imsg->hdr.len != IMSG_HEADER_SIZE + sizeof(struct ctl_show_status))
fatalx("invalid IMSG_CTL_SHOW_STATUS received");
cstatus = (struct ctl_show_status *)imsg->data;
if (cstatus->peercnt > 0)
printf("%d/%d peers valid, ",
cstatus->valid_peers, cstatus->peercnt);
if (cstatus->sensorcnt > 0)
printf("%d/%d sensors valid, ",
cstatus->valid_sensors, cstatus->sensorcnt);
if (cstatus->constraint_median) {
tv.tv_sec = cstatus->constraint_median +
(getmonotime() - cstatus->constraint_last);
tv.tv_usec = 0;
d_to_tv(gettime_from_timeval(&tv) - gettime(), &tv);
printf("constraint offset %llds", (long long)tv.tv_sec);
if (cstatus->constraint_errors)
printf(" (%d errors)",
cstatus->constraint_errors);
printf(", ");
}
if (cstatus->peercnt + cstatus->sensorcnt == 0)
printf("no peers and no sensors configured\n");
if (cstatus->synced == 1)
printf("clock synced, stratum %u\n", cstatus->stratum);
else {
printf("clock unsynced");
clock_offset = cstatus->clock_offset < 0 ?
-1.0 * cstatus->clock_offset : cstatus->clock_offset;
if (clock_offset > 5e-7)
printf(", clock offset is %.3fms\n",
cstatus->clock_offset);
else
printf("\n");
}
}
int
ntpd_adjtime(double d)
{
struct timeval tv, olddelta;
int synced = 0;
static int firstadj = 1;
if (d >= (double)LOG_NEGLIGEE / 1000 ||
d <= -1 * (double)LOG_NEGLIGEE / 1000)
log_info("adjusting local clock by %fs", d);
else
log_debug("adjusting local clock by %fs", d);
d_to_tv(d, &tv);
if (adjtime(&tv, &olddelta) == -1)
log_warn("adjtime failed");
else if (!firstadj && olddelta.tv_sec == 0 && olddelta.tv_usec == 0)
synced = 1;
firstadj = 0;
return (synced);
}
/* wake up when the system time changes underneath us */
static int sntp_clock_watch_setup(SNTPContext *sntp) {
struct itimerspec its = { .it_value.tv_sec = TIME_T_MAX };
_cleanup_close_ int fd = -1;
sd_event *e;
sd_event_source *source;
int r;
assert(sntp);
assert(sntp->event_receive);
fd = timerfd_create(CLOCK_REALTIME, TFD_NONBLOCK|TFD_CLOEXEC);
if (fd < 0) {
log_error("Failed to create timerfd: %m");
return -errno;
}
if (timerfd_settime(fd, TFD_TIMER_ABSTIME|TFD_TIMER_CANCEL_ON_SET, &its, NULL) < 0) {
log_error("Failed to set up timerfd: %m");
return -errno;
}
e = sd_event_source_get_event(sntp->event_receive);
r = sd_event_add_io(e, &source, fd, EPOLLIN, sntp_clock_watch, sntp);
if (r < 0) {
log_error("Failed to create clock watch event source: %s", strerror(-r));
return r;
}
sd_event_source_unref(sntp->event_clock_watch);
sntp->event_clock_watch = source;
if (sntp->clock_watch_fd >= 0)
close(sntp->clock_watch_fd);
sntp->clock_watch_fd = fd;
fd = -1;
return 0;
}
static int sntp_adjust_clock(SNTPContext *sntp, double offset, int leap_sec) {
struct timex tmx = {};
int r;
/*
* For small deltas, tell the kernel to gradually adjust the system
* clock to the NTP time, larger deltas are just directly set.
*
* Clear STA_UNSYNC, it will enable the kernel's 11-minute mode, which
* syncs the system time periodically to the hardware clock.
*/
if (offset < NTP_MAX_ADJUST && offset > -NTP_MAX_ADJUST) {
tmx.modes |= ADJ_STATUS | ADJ_OFFSET | ADJ_TIMECONST | ADJ_MAXERROR | ADJ_ESTERROR;
tmx.status = STA_PLL;
tmx.offset = offset * 1000 * 1000;
tmx.constant = log2i(sntp->poll_interval_usec / USEC_PER_SEC) - 6;
tmx.maxerror = 0;
tmx.esterror = 0;
log_debug(" adjust (slew): %+f sec\n", (double)tmx.offset / USEC_PER_SEC);
} else {
tmx.modes = ADJ_SETOFFSET;
d_to_tv(offset, &tmx.time);
sntp->jumped = true;
log_debug(" adjust (jump): %+f sec\n", tv_to_d(&tmx.time));
}
switch (leap_sec) {
case 1:
tmx.status |= STA_INS;
break;
case -1:
tmx.status |= STA_DEL;
break;
}
r = clock_adjtime(CLOCK_REALTIME, &tmx);
if (r < 0)
return r;
log_debug(" status : %04i %s\n"
" time now : %li.%06li\n"
" constant : %li\n"
" offset : %+f sec\n"
" freq offset : %+li (%+.3f ppm)\n",
tmx.status, tmx.status & STA_UNSYNC ? "" : "sync",
tmx.time.tv_sec, tmx.time.tv_usec,
tmx.constant,
(double)tmx.offset / USEC_PER_SEC,
tmx.freq, (double)tmx.freq / 65536);
return 0;
}
static bool sntp_sample_spike_detection(SNTPContext *sntp, double offset, double delay) {
unsigned int i, idx_cur, idx_new, idx_min;
double jitter;
double j;
/* store the current data in our samples array */
idx_cur = sntp->samples_idx;
idx_new = (idx_cur + 1) % ELEMENTSOF(sntp->samples);
sntp->samples_idx = idx_new;
sntp->samples[idx_new].offset = offset;
sntp->samples[idx_new].delay = delay;
sntp->packet_count++;
jitter = sntp->samples_jitter;
/* calculate new jitter value from the RMS differences relative to the lowest delay sample */
for (idx_min = idx_cur, i = 0; i < ELEMENTSOF(sntp->samples); i++)
if (sntp->samples[i].delay > 0 && sntp->samples[i].delay < sntp->samples[idx_min].delay)
idx_min = i;
j = 0;
for (i = 0; i < ELEMENTSOF(sntp->samples); i++)
j += square(sntp->samples[i].offset - sntp->samples[idx_min].offset);
sntp->samples_jitter = sqrt(j / (ELEMENTSOF(sntp->samples) - 1));
/* ignore samples when resyncing */
if (sntp->poll_resync)
return false;
/* always accept offset if we are farther off than the round-trip delay */
if (fabs(offset) > delay)
return false;
/* we need a few samples before looking at them */
if (sntp->packet_count < 4)
return false;
/* do not accept anything worse than the maximum possible error of the best sample */
if (fabs(offset) > sntp->samples[idx_min].delay)
return true;
/* compare the difference between the current offset to the previous offset and jitter */
return fabs(offset - sntp->samples[idx_cur].offset) > 3 * jitter;
}
