*
* Author: Adam Tkac <vonsch@gmail.com>
*
- * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*
* Parts of OpenNTPD clock syncronization code is replaced by
* code which is based on ntp-4.2.6, whuch carries the following
/* High-level description of the algorithm:
*
* We start running with very small poll_exp, BURSTPOLL,
- * in order to quickly accumulate INITIAL_SAMLPES datapoints
+ * in order to quickly accumulate INITIAL_SAMPLES datapoints
* for each peer. Then, time is stepped if the offset is larger
* than STEP_THRESHOLD, otherwise it isn't; anyway, we enlarge
* poll_exp to MINPOLL and enter frequency measurement step:
#define RETRY_INTERVAL 5 /* on error, retry in N secs */
#define RESPONSE_INTERVAL 15 /* wait for reply up to N secs */
-#define INITIAL_SAMLPES 4 /* how many samples do we want for init */
+#define INITIAL_SAMPLES 4 /* how many samples do we want for init */
/* Clock discipline parameters and constants */
//UNUSED: #define PANIC_THRESHOLD 1000 /* panic threshold (sec) */
#define FREQ_TOLERANCE 0.000015 /* frequency tolerance (15 PPM) */
-#define BURSTPOLL 0 /* initial poll */
+#define BURSTPOLL 0 /* initial poll */
#define MINPOLL 5 /* minimum poll interval. std ntpd uses 6 (6: 64 sec) */
#define BIGPOLL 10 /* drop to lower poll at any trouble (10: 17 min) */
#define MAXPOLL 12 /* maximum poll interval (12: 1.1h, 17: 36.4h). std ntpd uses 17 */
p->filter_offset, x,
p->filter_dispersion,
p->filter_jitter);
-
}
static void
for (i = 0; i < NUM_DATAPOINTS; i++) {
if (small_ofs) {
- p->filter_datapoint[i].d_recv_time -= offset;
+ p->filter_datapoint[i].d_recv_time += offset;
if (p->filter_datapoint[i].d_offset != 0) {
- p->filter_datapoint[i].d_offset -= offset;
+ p->filter_datapoint[i].d_offset += offset;
}
} else {
p->filter_datapoint[i].d_recv_time = G.cur_time;
}
}
if (small_ofs) {
- p->lastpkt_recv_time -= offset;
+ p->lastpkt_recv_time += offset;
} else {
p->reachable_bits = 0;
p->lastpkt_recv_time = G.cur_time;
}
filter_datapoints(p); /* recalc p->filter_xxx */
- p->next_action_time -= offset;
VERB5 bb_error_msg("%s->lastpkt_recv_time=%f", p->p_dotted, p->lastpkt_recv_time);
}
}
+/* Note that there is no provision to prevent several run_scripts
+ * to be done in quick succession. In fact, it happens rather often
+ * if initial syncronization results in a step.
+ * You will see "step" and then "stratum" script runs, sometimes
+ * as close as only 0.002 seconds apart.
+ * Script should be ready to deal with this.
+ */
static void run_script(const char *action, double offset)
{
char *argv[3];
/* Don't want to wait: it may run hwclock --systohc, and that
* may take some time (seconds): */
- /*wait4pid(spawn(argv));*/
+ /*spawn_and_wait(argv);*/
spawn(argv);
unsetenv("stratum");
for (item = G.ntp_peers; item != NULL; item = item->link) {
peer_t *pp = (peer_t *) item->data;
reset_peer_stats(pp, offset);
+ //bb_error_msg("offset:%f pp->next_action_time:%f -> %f",
+ // offset, pp->next_action_time, pp->next_action_time + offset);
+ pp->next_action_time += offset;
}
/* Globals: */
- G.cur_time -= offset;
- G.last_update_recv_time -= offset;
- G.last_script_run -= offset;
+ G.cur_time += offset;
+ G.last_update_recv_time += offset;
+ G.last_script_run += offset;
}
VERB3 bb_error_msg("peer %s unfit for selection: unreachable", p->p_dotted);
return 0;
}
-#if 0 /* we filter out such packets earlier */
+#if 0 /* we filter out such packets earlier */
if ((p->lastpkt_status & LI_ALARM) == LI_ALARM
|| p->lastpkt_stratum >= MAXSTRAT
) {
abs_offset = fabs(offset);
#if 0
- /* If needed, -S script can detect this by looking at $offset
- * env var and kill parent */
+ /* If needed, -S script can do it by looking at $offset
+ * env var and killing parent */
/* If the offset is too large, give up and go home */
if (abs_offset > PANIC_THRESHOLD) {
bb_error_msg_and_die("offset %f far too big, exiting", offset);
/* this time was obtained between poll() and recv() */
msg.m_rectime = d_to_lfp(G.cur_time);
msg.m_xmttime = d_to_lfp(gettime1900d()); /* this instant */
+ if (G.peer_cnt == 0) {
+ /* we have no peers: "stratum 1 server" mode. reftime = our own time */
+ G.reftime = G.cur_time;
+ }
msg.m_reftime = d_to_lfp(G.reftime);
msg.m_orgtime = query_xmttime;
msg.m_rootdelay = d_to_sfp(G.rootdelay);
bb_show_usage();
// if (opts & OPT_x) /* disable stepping, only slew is allowed */
// G.time_was_stepped = 1;
- while (peers)
- add_peers(llist_pop(&peers));
+ if (peers) {
+ while (peers)
+ add_peers(llist_pop(&peers));
+ } else {
+ /* -l but no peers: "stratum 1 server" mode */
+ G.stratum = 1;
+ }
if (!(opts & OPT_n)) {
bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO, argv);
logmode = LOGMODE_NONE;
if (opts & OPT_N)
setpriority(PRIO_PROCESS, 0, -15);
- bb_signals((1 << SIGTERM) | (1 << SIGINT), record_signo);
- /* Removed SIGHUP here: */
- bb_signals((1 << SIGPIPE) | (1 << SIGCHLD), SIG_IGN);
+ /* If network is up, syncronization occurs in ~10 seconds.
+ * We give "ntpd -q" a full minute to finish, then we exit.
+ *
+ * I tested ntpd 4.2.6p1 and apparently it never exits
+ * (will try forever), but it does not feel right.
+ * The goal of -q is to act like ntpdate: set time
+ * after a reasonably small period of polling, or fail.
+ */
+ if (opts & OPT_q)
+ alarm(60);
+
+ bb_signals(0
+ | (1 << SIGTERM)
+ | (1 << SIGINT)
+ | (1 << SIGALRM)
+ , record_signo
+ );
+ bb_signals(0
+ | (1 << SIGPIPE)
+ | (1 << SIGCHLD)
+ , SIG_IGN
+ );
}
int ntpd_main(int argc UNUSED_PARAM, char **argv) MAIN_EXTERNALLY_VISIBLE;
idx2peer = xzalloc(sizeof(idx2peer[0]) * cnt);
pfd = xzalloc(sizeof(pfd[0]) * cnt);
- /* Countdown: we never sync before we sent INITIAL_SAMLPES+1
+ /* Countdown: we never sync before we sent INITIAL_SAMPLES+1
* packets to each peer.
* NB: if some peer is not responding, we may end up sending
* fewer packets to it and more to other peers.
- * NB2: sync usually happens using INITIAL_SAMLPES packets,
+ * NB2: sync usually happens using INITIAL_SAMPLES packets,
* since last reply does not come back instantaneously.
*/
- cnt = G.peer_cnt * (INITIAL_SAMLPES + 1);
+ cnt = G.peer_cnt * (INITIAL_SAMPLES + 1);
while (!bb_got_signal) {
llist_t *item;
nfds = poll(pfd, i, timeout * 1000);
gettime1900d(); /* sets G.cur_time */
if (nfds <= 0) {
- if (G.cur_time - G.last_script_run > 11*60) {
+ if (G.script_name && G.cur_time - G.last_script_run > 11*60) {
/* Useful for updating battery-backed RTC and such */
run_script("periodic", G.last_update_offset);
gettime1900d(); /* sets G.cur_time */
static double
direct_freq(double fp_offset)
{
-
#ifdef KERNEL_PLL
/*
* If the kernel is enabled, we need the residual offset to
}
static void
-set_freq(double freq) /* frequency update */
+set_freq(double freq) /* frequency update */
{
char tbuf[80];
projects / oweals / busybox.git / blobdiff