/*
* NTP client/server, based on OpenNTPD 3.9p1
*
- * Author: Adam Tkac <vonsch@gmail.com>
+ * Busybox port author: Adam Tkac (C) 2009 <vonsch@gmail.com>
*
- * Licensed under GPLv2, see file LICENSE in this source tree.
+ * OpenNTPd 3.9p1 copyright holders:
+ * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
+ * Copyright (c) 2004 Alexander Guy <alexander.guy@andern.org>
+ *
+ * OpenNTPd code is licensed under ISC-style licence:
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ ***********************************************************************
*
* Parts of OpenNTPD clock syncronization code is replaced by
- * code which is based on ntp-4.2.6, whuch carries the following
+ * code which is based on ntp-4.2.6, which carries the following
* copyright notice:
*
- ***********************************************************************
- * *
- * Copyright (c) University of Delaware 1992-2009 *
- * *
- * Permission to use, copy, modify, and distribute this software and *
- * its documentation for any purpose with or without fee is hereby *
- * granted, provided that the above copyright notice appears in all *
- * copies and that both the copyright notice and this permission *
- * notice appear in supporting documentation, and that the name *
- * University of Delaware not be used in advertising or publicity *
- * pertaining to distribution of the software without specific, *
- * written prior permission. The University of Delaware makes no *
- * representations about the suitability this software for any *
- * purpose. It is provided "as is" without express or implied *
- * warranty. *
- * *
+ * Copyright (c) University of Delaware 1992-2009
+ *
+ * Permission to use, copy, modify, and distribute this software and
+ * its documentation for any purpose with or without fee is hereby
+ * granted, provided that the above copyright notice appears in all
+ * copies and that both the copyright notice and this permission
+ * notice appear in supporting documentation, and that the name
+ * University of Delaware not be used in advertising or publicity
+ * pertaining to distribution of the software without specific,
+ * written prior permission. The University of Delaware makes no
+ * representations about the suitability this software for any
+ * purpose. It is provided "as is" without express or implied warranty.
***********************************************************************
*/
+//config:config NTPD
+//config: bool "ntpd"
+//config: default y
+//config: select PLATFORM_LINUX
+//config: help
+//config: The NTP client/server daemon.
+//config:
+//config:config FEATURE_NTPD_SERVER
+//config: bool "Make ntpd usable as a NTP server"
+//config: default y
+//config: depends on NTPD
+//config: help
+//config: Make ntpd usable as a NTP server. If you disable this option
+//config: ntpd will be usable only as a NTP client.
+//config:
+//config:config FEATURE_NTPD_CONF
+//config: bool "Make ntpd understand /etc/ntp.conf"
+//config: default y
+//config: depends on NTPD
+//config: help
+//config: Make ntpd look in /etc/ntp.conf for peers. Only "server address"
+//config: is supported.
+
+//applet:IF_NTPD(APPLET(ntpd, BB_DIR_USR_SBIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_NTPD) += ntpd.o
//usage:#define ntpd_trivial_usage
-//usage: "[-dnqNw"IF_FEATURE_NTPD_SERVER("l")"] [-S PROG] [-p PEER]..."
+//usage: "[-dnqNw"IF_FEATURE_NTPD_SERVER("l -I IFACE")"] [-S PROG] [-p PEER]..."
//usage:#define ntpd_full_usage "\n\n"
//usage: "NTP client/server\n"
//usage: "\n -d Verbose"
//usage: "\n -q Quit after clock is set"
//usage: "\n -N Run at high priority"
//usage: "\n -w Do not set time (only query peers), implies -n"
-//usage: IF_FEATURE_NTPD_SERVER(
-//usage: "\n -l Run as server on port 123"
-//usage: )
//usage: "\n -S PROG Run PROG after stepping time, stratum change, and every 11 mins"
//usage: "\n -p PEER Obtain time from PEER (may be repeated)"
+//usage: IF_FEATURE_NTPD_CONF(
+//usage: "\n If -p is not given, 'server HOST' lines"
+//usage: "\n from /etc/ntp.conf are used"
+//usage: )
+//usage: IF_FEATURE_NTPD_SERVER(
+//usage: "\n -l Also run as server on port 123"
+//usage: "\n -I IFACE Bind server to IFACE, implies -l"
+//usage: )
+
+// -l and -p options are not compatible with "standard" ntpd:
+// it has them as "-l logfile" and "-p pidfile".
+// -S and -w are not compat either, "standard" ntpd has no such opts.
#include "libbb.h"
#include <math.h>
#ifndef IPTOS_LOWDELAY
# define IPTOS_LOWDELAY 0x10
#endif
-#ifndef IP_PKTINFO
-# error "Sorry, your kernel has to support IP_PKTINFO"
-#endif
/* Verbosity control (max level of -dddd options accepted).
*
* Made some changes to speed up re-syncing after our clock goes bad
* (tested with suspending my laptop):
- * - if largish offset (>= STEP_THRESHOLD * 8 == 1 sec) is seen
+ * - if largish offset (>= STEP_THRESHOLD == 1 sec) is seen
* from a peer, schedule next query for this peer soon
* without drastically lowering poll interval for everybody.
* This makes us collect enough data for step much faster:
* datapoints after the step.
*/
-#define RETRY_INTERVAL 5 /* on error, retry in N secs */
-#define RESPONSE_INTERVAL 15 /* wait for reply up to N secs */
#define INITIAL_SAMPLES 4 /* how many samples do we want for init */
#define BAD_DELAY_GROWTH 4 /* drop packet if its delay grew by more than this */
-/* Clock discipline parameters and constants */
+#define RETRY_INTERVAL 32 /* on send/recv error, retry in N secs (need to be power of 2) */
+#define NOREPLY_INTERVAL 512 /* sent, but got no reply: cap next query by this many seconds */
+#define RESPONSE_INTERVAL 16 /* wait for reply up to N secs */
+#define HOSTNAME_INTERVAL 5 /* hostname lookup failed. Wait N secs for next try */
/* Step threshold (sec). std ntpd uses 0.128.
- * Using exact power of 2 (1/8) results in smaller code */
-#define STEP_THRESHOLD 0.125
-#define WATCH_THRESHOLD 128 /* stepout threshold (sec). std ntpd uses 900 (11 mins (!)) */
+ */
+#define STEP_THRESHOLD 1
+/* Slew threshold (sec): adjtimex() won't accept offsets larger than this.
+ * Using exact power of 2 (1/8) results in smaller code
+ */
+#define SLEW_THRESHOLD 0.125
+/* Stepout threshold (sec). std ntpd uses 900 (11 mins (!)) */
+#define WATCH_THRESHOLD 128
/* NB: set WATCH_THRESHOLD to ~60 when debugging to save time) */
//UNUSED: #define PANIC_THRESHOLD 1000 /* panic threshold (sec) */
+/*
+ * If we got |offset| > BIGOFF from a peer, cap next query interval
+ * for this peer by this many seconds:
+ */
+#define BIGOFF STEP_THRESHOLD
+#define BIGOFF_INTERVAL (1 << 7) /* 128 s */
+
#define FREQ_TOLERANCE 0.000015 /* frequency tolerance (15 PPM) */
#define BURSTPOLL 0 /* initial poll */
#define MINPOLL 5 /* minimum poll interval. std ntpd uses 6 (6: 64 sec) */
-/* If we got largish offset from a peer, cap next query interval
- * for this peer by this many seconds:
- */
-#define BIGOFF_INTERVAL (1 << 6)
-/* If offset > discipline_jitter * POLLADJ_GATE, and poll interval is >= 2^BIGPOLL,
- * then it is decreased _at once_. (If < 2^BIGPOLL, it will be decreased _eventually_).
+/*
+ * If offset > discipline_jitter * POLLADJ_GATE, and poll interval is > 2^BIGPOLL,
+ * then it is decreased _at once_. (If <= 2^BIGPOLL, it will be decreased _eventually_).
*/
-#define BIGPOLL 10 /* 2^10 sec ~= 17 min */
+#define BIGPOLL 9 /* 2^9 sec ~= 8.5 min */
#define MAXPOLL 12 /* maximum poll interval (12: 1.1h, 17: 36.4h). std ntpd uses 17 */
-/* Actively lower poll when we see such big offsets.
- * With STEP_THRESHOLD = 0.125, it means we try to sync more aggressively
- * if offset increases over ~0.04 sec */
-#define POLLDOWN_OFFSET (STEP_THRESHOLD / 3)
+/*
+ * Actively lower poll when we see such big offsets.
+ * With SLEW_THRESHOLD = 0.125, it means we try to sync more aggressively
+ * if offset increases over ~0.04 sec
+ */
+//#define POLLDOWN_OFFSET (SLEW_THRESHOLD / 3)
#define MINDISP 0.01 /* minimum dispersion (sec) */
#define MAXDISP 16 /* maximum dispersion (sec) */
#define MAXSTRAT 16 /* maximum stratum (infinity metric) */
* or when receive times out (if p_fd >= 0): */
double next_action_time;
double p_xmttime;
+ double p_raw_delay;
+ /* p_raw_delay is set even by "high delay" packets */
+ /* lastpkt_delay isn't */
double lastpkt_recv_time;
double lastpkt_delay;
double lastpkt_rootdelay;
datapoint_t filter_datapoint[NUM_DATAPOINTS];
/* last sent packet: */
msg_t p_xmt_msg;
+ char p_hostname[1];
} peer_t;
OPT_p = (1 << 5),
OPT_S = (1 << 6),
OPT_l = (1 << 7) * ENABLE_FEATURE_NTPD_SERVER,
+ OPT_I = (1 << 8) * ENABLE_FEATURE_NTPD_SERVER,
/* We hijack some bits for other purposes */
OPT_qq = (1 << 31),
};
llist_t *ntp_peers;
#if ENABLE_FEATURE_NTPD_SERVER
int listen_fd;
+ char *if_name;
# define G_listen_fd (G.listen_fd)
#else
# define G_listen_fd (-1)
*/
#define G_precision_sec 0.002
uint8_t stratum;
- /* Bool. After set to 1, never goes back to 0: */
- smallint initial_poll_complete;
#define STATE_NSET 0 /* initial state, "nothing is set" */
//#define STATE_FSET 1 /* frequency set from file */
};
#define G (*ptr_to_globals)
-static const int const_IPTOS_LOWDELAY = IPTOS_LOWDELAY;
-
#define VERB1 if (MAX_VERBOSE && G.verbose)
#define VERB2 if (MAX_VERBOSE >= 2 && G.verbose >= 2)
reset_peer_stats(peer_t *p, double offset)
{
int i;
- bool small_ofs = fabs(offset) < 16 * STEP_THRESHOLD;
+ bool small_ofs = fabs(offset) < STEP_THRESHOLD;
/* Used to set p->filter_datapoint[i].d_dispersion = MAXDISP
* and clear reachable bits, but this proved to be too agressive:
- * after step (tested with suspinding laptop for ~30 secs),
+ * after step (tested with suspending laptop for ~30 secs),
* this caused all previous data to be considered invalid,
* making us needing to collect full ~8 datapoins per peer
* after step in order to start trusting them.
VERB6 bb_error_msg("%s->lastpkt_recv_time=%f", p->p_dotted, p->lastpkt_recv_time);
}
+static len_and_sockaddr*
+resolve_peer_hostname(peer_t *p)
+{
+ len_and_sockaddr *lsa = host2sockaddr(p->p_hostname, 123);
+ if (lsa) {
+ free(p->p_lsa);
+ free(p->p_dotted);
+ p->p_lsa = lsa;
+ p->p_dotted = xmalloc_sockaddr2dotted_noport(&lsa->u.sa);
+ } else {
+ /* error message is emitted by host2sockaddr() */
+ set_next(p, HOSTNAME_INTERVAL);
+ }
+ return lsa;
+}
+
static void
-add_peers(char *s)
+add_peers(const char *s)
{
+ llist_t *item;
peer_t *p;
- p = xzalloc(sizeof(*p));
- p->p_lsa = xhost2sockaddr(s, 123);
- p->p_dotted = xmalloc_sockaddr2dotted_noport(&p->p_lsa->u.sa);
+ p = xzalloc(sizeof(*p) + strlen(s));
+ strcpy(p->p_hostname, s);
p->p_fd = -1;
p->p_xmt_msg.m_status = MODE_CLIENT | (NTP_VERSION << 3);
p->next_action_time = G.cur_time; /* = set_next(p, 0); */
- reset_peer_stats(p, 16 * STEP_THRESHOLD);
+ reset_peer_stats(p, STEP_THRESHOLD);
+
+ /* Names like N.<country2chars>.pool.ntp.org are randomly resolved
+ * to a pool of machines. Sometimes different N's resolve to the same IP.
+ * It is not useful to have two peers with same IP. We skip duplicates.
+ */
+ if (resolve_peer_hostname(p)) {
+ for (item = G.ntp_peers; item != NULL; item = item->link) {
+ peer_t *pp = (peer_t *) item->data;
+ if (pp->p_dotted && strcmp(p->p_dotted, pp->p_dotted) == 0) {
+ bb_error_msg("duplicate peer %s (%s)", s, p->p_dotted);
+ free(p->p_lsa);
+ free(p->p_dotted);
+ free(p);
+ return;
+ }
+ }
+ }
llist_add_to(&G.ntp_peers, p);
G.peer_cnt++;
static void
send_query_to_peer(peer_t *p)
{
+ if (!p->p_lsa) {
+ if (!resolve_peer_hostname(p))
+ return;
+ }
+
/* Why do we need to bind()?
* See what happens when we don't bind:
*
#if ENABLE_FEATURE_IPV6
if (family == AF_INET)
#endif
- setsockopt(fd, IPPROTO_IP, IP_TOS, &const_IPTOS_LOWDELAY, sizeof(const_IPTOS_LOWDELAY));
+ setsockopt_int(fd, IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY);
free(local_lsa);
}
*
* Save the real transmit timestamp locally.
*/
- p->p_xmt_msg.m_xmttime.int_partl = random();
- p->p_xmt_msg.m_xmttime.fractionl = random();
+ p->p_xmt_msg.m_xmttime.int_partl = rand();
+ p->p_xmt_msg.m_xmttime.fractionl = rand();
p->p_xmttime = gettime1900d();
/* Were doing it only if sendto worked, but
}
}
+static void clamp_pollexp_and_set_MAXSTRAT(void)
+{
+ if (G.poll_exp < MINPOLL)
+ G.poll_exp = MINPOLL;
+ if (G.poll_exp > BIGPOLL)
+ G.poll_exp = BIGPOLL;
+ G.polladj_count = 0;
+ G.stratum = MAXSTRAT;
+}
+
/*
* Selection and clustering, and their helpers
num_points = 0;
item = G.ntp_peers;
- if (G.initial_poll_complete) while (item != NULL) {
+ while (item != NULL) {
double rd, offset;
p = (peer_t *) item->data;
exit(0);
}
- G.polladj_count = 0;
- G.poll_exp = MINPOLL;
- G.stratum = MAXSTRAT;
+ clamp_pollexp_and_set_MAXSTRAT();
run_script("step", offset);
#endif
abs_offset = offset = 0;
set_new_values(STATE_SYNC, offset, recv_time);
-
} else { /* abs_offset <= STEP_THRESHOLD */
- if (G.poll_exp < MINPOLL && G.initial_poll_complete) {
- VERB4 bb_error_msg("small offset:%+f, disabling burst mode", offset);
- G.polladj_count = 0;
- G.poll_exp = MINPOLL;
- }
+ /* The ratio is calculated before jitter is updated to make
+ * poll adjust code more sensitive to large offsets.
+ */
+ G.offset_to_jitter_ratio = abs_offset / G.discipline_jitter;
/* Compute the clock jitter as the RMS of exponentially
* weighted offset differences. Used by the poll adjust code.
etemp = SQUARE(G.discipline_jitter);
dtemp = SQUARE(offset - G.last_update_offset);
G.discipline_jitter = SQRT(etemp + (dtemp - etemp) / AVG);
+ if (G.discipline_jitter < G_precision_sec)
+ G.discipline_jitter = G_precision_sec;
switch (G.discipline_state) {
case STATE_NSET:
}
}
- if (G.discipline_jitter < G_precision_sec)
- G.discipline_jitter = G_precision_sec;
- G.offset_to_jitter_ratio = abs_offset / G.discipline_jitter;
-
G.reftime = G.cur_time;
G.ntp_status = p->lastpkt_status;
G.refid = p->lastpkt_refid;
tmx.freq = G.discipline_freq_drift * 65536e6;
#endif
tmx.modes = ADJ_OFFSET | ADJ_STATUS | ADJ_TIMECONST;// | ADJ_MAXERROR | ADJ_ESTERROR;
- tmx.offset = (offset * 1000000); /* usec */
- tmx.status = STA_PLL;
- if (G.ntp_status & LI_PLUSSEC)
- tmx.status |= STA_INS;
- if (G.ntp_status & LI_MINUSSEC)
- tmx.status |= STA_DEL;
-
- tmx.constant = G.poll_exp - 4;
+ tmx.constant = (int)G.poll_exp - 4;
/* EXPERIMENTAL.
* The below if statement should be unnecessary, but...
* It looks like Linux kernel's PLL is far too gentle in changing
* To be on a safe side, let's do it only if offset is significantly
* larger than jitter.
*/
- if (tmx.constant > 0 && G.offset_to_jitter_ratio >= TIMECONST_HACK_GATE)
+ if (G.offset_to_jitter_ratio >= TIMECONST_HACK_GATE)
tmx.constant--;
+ tmx.offset = (long)(offset * 1000000); /* usec */
+ if (SLEW_THRESHOLD < STEP_THRESHOLD) {
+ if (tmx.offset > (long)(SLEW_THRESHOLD * 1000000)) {
+ tmx.offset = (long)(SLEW_THRESHOLD * 1000000);
+ tmx.constant--;
+ }
+ if (tmx.offset < -(long)(SLEW_THRESHOLD * 1000000)) {
+ tmx.offset = -(long)(SLEW_THRESHOLD * 1000000);
+ tmx.constant--;
+ }
+ }
+ if (tmx.constant < 0)
+ tmx.constant = 0;
+
+ tmx.status = STA_PLL;
+ if (G.ntp_status & LI_PLUSSEC)
+ tmx.status |= STA_INS;
+ if (G.ntp_status & LI_MINUSSEC)
+ tmx.status |= STA_DEL;
//tmx.esterror = (uint32_t)(clock_jitter * 1e6);
//tmx.maxerror = (uint32_t)((sys_rootdelay / 2 + sys_rootdisp) * 1e6);
VERB4 bb_error_msg("adjtimex:%d freq:%ld offset:%+ld status:0x%x",
rc, tmx.freq, tmx.offset, tmx.status);
G.kernel_freq_drift = tmx.freq / 65536;
- VERB2 bb_error_msg("update from:%s offset:%+f jitter:%f clock drift:%+.3fppm tc:%d",
- p->p_dotted, offset, G.discipline_jitter, (double)tmx.freq / 65536, (int)tmx.constant);
+ VERB2 bb_error_msg("update from:%s offset:%+f delay:%f jitter:%f clock drift:%+.3fppm tc:%d",
+ p->p_dotted,
+ offset,
+ p->lastpkt_delay,
+ G.discipline_jitter,
+ (double)tmx.freq / 65536,
+ (int)tmx.constant
+ );
return 1; /* "ok to increase poll interval" */
}
* (helpers first)
*/
static unsigned
-retry_interval(void)
+poll_interval(int upper_bound)
{
- /* Local problem, want to retry soon */
- unsigned interval, r;
- interval = RETRY_INTERVAL;
- r = random();
- interval += r % (unsigned)(RETRY_INTERVAL / 4);
- VERB4 bb_error_msg("chose retry interval:%u", interval);
+ unsigned interval, r, mask;
+ interval = 1 << G.poll_exp;
+ if (interval > upper_bound)
+ interval = upper_bound;
+ mask = ((interval-1) >> 4) | 1;
+ r = rand();
+ interval += r & mask; /* ~ random(0..1) * interval/16 */
+ VERB4 bb_error_msg("chose poll interval:%u (poll_exp:%d)", interval, G.poll_exp);
return interval;
}
-static unsigned
-poll_interval(int exponent)
+static void
+adjust_poll(int count)
{
- unsigned interval, r;
- exponent = G.poll_exp + exponent;
- if (exponent < 0)
- exponent = 0;
- interval = 1 << exponent;
- r = random();
- interval += ((r & (interval-1)) >> 4) + ((r >> 8) & 1); /* + 1/16 of interval, max */
- VERB4 bb_error_msg("chose poll interval:%u (poll_exp:%d exp:%d)", interval, G.poll_exp, exponent);
- return interval;
+ G.polladj_count += count;
+ if (G.polladj_count > POLLADJ_LIMIT) {
+ G.polladj_count = 0;
+ if (G.poll_exp < MAXPOLL) {
+ G.poll_exp++;
+ VERB4 bb_error_msg("polladj: discipline_jitter:%f ++poll_exp=%d",
+ G.discipline_jitter, G.poll_exp);
+ }
+ } else if (G.polladj_count < -POLLADJ_LIMIT || (count < 0 && G.poll_exp > BIGPOLL)) {
+ G.polladj_count = 0;
+ if (G.poll_exp > MINPOLL) {
+ llist_t *item;
+
+ G.poll_exp--;
+ /* Correct p->next_action_time in each peer
+ * which waits for sending, so that they send earlier.
+ * Old pp->next_action_time are on the order
+ * of t + (1 << old_poll_exp) + small_random,
+ * we simply need to subtract ~half of that.
+ */
+ for (item = G.ntp_peers; item != NULL; item = item->link) {
+ peer_t *pp = (peer_t *) item->data;
+ if (pp->p_fd < 0)
+ pp->next_action_time -= (1 << G.poll_exp);
+ }
+ VERB4 bb_error_msg("polladj: discipline_jitter:%f --poll_exp=%d",
+ G.discipline_jitter, G.poll_exp);
+ }
+ } else {
+ VERB4 bb_error_msg("polladj: count:%d", G.polladj_count);
+ }
}
static NOINLINE void
recv_and_process_peer_pkt(peer_t *p)
ssize_t size;
msg_t msg;
double T1, T2, T3, T4;
- double dv, offset;
+ double offset;
+ double prev_delay, delay;
unsigned interval;
datapoint_t *datapoint;
peer_t *q;
* ntp servers reply from their *other IP*.
* TODO: maybe we should check at least what we can: from.port == 123?
*/
+ recv_again:
size = recv(p->p_fd, &msg, sizeof(msg), MSG_DONTWAIT);
- if (size == -1) {
- bb_perror_msg("recv(%s) error", p->p_dotted);
- if (errno == EHOSTUNREACH || errno == EHOSTDOWN
- || errno == ENETUNREACH || errno == ENETDOWN
- || errno == ECONNREFUSED || errno == EADDRNOTAVAIL
- || errno == EAGAIN
- ) {
-//TODO: always do this?
- interval = retry_interval();
- goto set_next_and_ret;
- }
- xfunc_die();
+ if (size < 0) {
+ if (errno == EINTR)
+ /* Signal caught */
+ goto recv_again;
+ if (errno == EAGAIN)
+ /* There was no packet after all
+ * (poll() returning POLLIN for a fd
+ * is not a ironclad guarantee that data is there)
+ */
+ return;
+ /*
+ * If you need a different handling for a specific
+ * errno, always explain it in comment.
+ */
+ bb_perror_msg_and_die("recv(%s) error", p->p_dotted);
}
if (size != NTP_MSGSIZE_NOAUTH && size != NTP_MSGSIZE) {
|| msg.m_stratum == 0
|| msg.m_stratum > NTP_MAXSTRATUM
) {
-// TODO: stratum 0 responses may have commands in 32-bit m_refid field:
-// "DENY", "RSTR" - peer does not like us at all
-// "RATE" - peer is overloaded, reduce polling freq
bb_error_msg("reply from %s: peer is unsynced", p->p_dotted);
+ /*
+ * Stratum 0 responses may have commands in 32-bit m_refid field:
+ * "DENY", "RSTR" - peer does not like us at all,
+ * "RATE" - peer is overloaded, reduce polling freq.
+ * If poll interval is small, increase it.
+ */
+ if (G.poll_exp < BIGPOLL)
+ goto increase_interval;
goto pick_normal_interval;
}
// if (msg.m_rootdelay / 2 + msg.m_rootdisp >= MAXDISP || p->lastpkt_reftime > msg.m_xmt)
// return; /* invalid header values */
- p->lastpkt_status = msg.m_status;
- p->lastpkt_stratum = msg.m_stratum;
- p->lastpkt_rootdelay = sfp_to_d(msg.m_rootdelay);
- p->lastpkt_rootdisp = sfp_to_d(msg.m_rootdisp);
- p->lastpkt_refid = msg.m_refid;
-
/*
* From RFC 2030 (with a correction to the delay math):
*
T3 = lfp_to_d(msg.m_xmttime);
T4 = G.cur_time;
- p->lastpkt_recv_time = T4;
- VERB6 bb_error_msg("%s->lastpkt_recv_time=%f", p->p_dotted, p->lastpkt_recv_time);
-
/* The delay calculation is a special case. In cases where the
* server and client clocks are running at different rates and
* with very fast networks, the delay can appear negative. In
* order to avoid violating the Principle of Least Astonishment,
* the delay is clamped not less than the system precision.
*/
- dv = p->lastpkt_delay;
- p->lastpkt_delay = (T4 - T1) - (T3 - T2);
- if (p->lastpkt_delay < G_precision_sec)
- p->lastpkt_delay = G_precision_sec;
+ delay = (T4 - T1) - (T3 - T2);
+ if (delay < G_precision_sec)
+ delay = G_precision_sec;
/*
* If this packet's delay is much bigger than the last one,
* it's better to just ignore it than use its much less precise value.
*/
- if (p->reachable_bits && p->lastpkt_delay > dv * BAD_DELAY_GROWTH) {
- bb_error_msg("reply from %s: delay %f is too high, ignoring", p->p_dotted, p->lastpkt_delay);
+ prev_delay = p->p_raw_delay;
+ p->p_raw_delay = delay;
+ if (p->reachable_bits && delay > prev_delay * BAD_DELAY_GROWTH) {
+ bb_error_msg("reply from %s: delay %f is too high, ignoring", p->p_dotted, delay);
goto pick_normal_interval;
}
+ p->lastpkt_delay = delay;
+ p->lastpkt_recv_time = T4;
+ VERB6 bb_error_msg("%s->lastpkt_recv_time=%f", p->p_dotted, p->lastpkt_recv_time);
+ p->lastpkt_status = msg.m_status;
+ p->lastpkt_stratum = msg.m_stratum;
+ p->lastpkt_rootdelay = sfp_to_d(msg.m_rootdelay);
+ p->lastpkt_rootdisp = sfp_to_d(msg.m_rootdisp);
+ p->lastpkt_refid = msg.m_refid;
+
p->datapoint_idx = p->reachable_bits ? (p->datapoint_idx + 1) % NUM_DATAPOINTS : 0;
datapoint = &p->filter_datapoint[p->datapoint_idx];
datapoint->d_recv_time = T4;
/* Muck with statictics and update the clock */
filter_datapoints(p);
q = select_and_cluster();
- rc = -1;
+ rc = 0;
if (q) {
- rc = 0;
if (!(option_mask32 & OPT_w)) {
rc = update_local_clock(q);
+#if 0
+//Disabled this because there is a case where largish offsets
+//are unavoidable: if network round-trip delay is, say, ~0.6s,
+//error in offset estimation would be ~delay/2 ~= 0.3s.
+//Thus, offsets will be usually in -0.3...0.3s range.
+//In this case, this code would keep poll interval small,
+//but it won't be helping.
+//BIGOFF check below deals with a case of seeing multi-second offsets.
+
/* If drift is dangerously large, immediately
* drop poll interval one step down.
*/
if (fabs(q->filter_offset) >= POLLDOWN_OFFSET) {
VERB4 bb_error_msg("offset:%+f > POLLDOWN_OFFSET", q->filter_offset);
- goto poll_down;
+ adjust_poll(-POLLADJ_LIMIT * 3);
+ rc = 0;
}
+#endif
}
+ } else {
+ /* No peer selected.
+ * If poll interval is small, increase it.
+ */
+ if (G.poll_exp < BIGPOLL)
+ goto increase_interval;
}
- /* else: no peer selected, rc = -1: we want to poll more often */
if (rc != 0) {
/* Adjust the poll interval by comparing the current offset
if (rc > 0 && G.offset_to_jitter_ratio <= POLLADJ_GATE) {
/* was += G.poll_exp but it is a bit
* too optimistic for my taste at high poll_exp's */
- G.polladj_count += MINPOLL;
- if (G.polladj_count > POLLADJ_LIMIT) {
- G.polladj_count = 0;
- if (G.poll_exp < MAXPOLL) {
- G.poll_exp++;
- VERB4 bb_error_msg("polladj: discipline_jitter:%f ++poll_exp=%d",
- G.discipline_jitter, G.poll_exp);
- }
- } else {
- VERB4 bb_error_msg("polladj: incr:%d", G.polladj_count);
- }
+ increase_interval:
+ adjust_poll(MINPOLL);
} else {
- G.polladj_count -= G.poll_exp * 2;
- if (G.polladj_count < -POLLADJ_LIMIT || G.poll_exp >= BIGPOLL) {
- poll_down:
- G.polladj_count = 0;
- if (G.poll_exp > MINPOLL) {
- llist_t *item;
-
- G.poll_exp--;
- /* Correct p->next_action_time in each peer
- * which waits for sending, so that they send earlier.
- * Old pp->next_action_time are on the order
- * of t + (1 << old_poll_exp) + small_random,
- * we simply need to subtract ~half of that.
- */
- for (item = G.ntp_peers; item != NULL; item = item->link) {
- peer_t *pp = (peer_t *) item->data;
- if (pp->p_fd < 0)
- pp->next_action_time -= (1 << G.poll_exp);
- }
- VERB4 bb_error_msg("polladj: discipline_jitter:%f --poll_exp=%d",
- G.discipline_jitter, G.poll_exp);
- }
- } else {
- VERB4 bb_error_msg("polladj: decr:%d", G.polladj_count);
- }
+ VERB3 if (rc > 0)
+ bb_error_msg("want smaller interval: offset/jitter = %u",
+ G.offset_to_jitter_ratio);
+ adjust_poll(-G.poll_exp * 2);
}
}
/* Decide when to send new query for this peer */
pick_normal_interval:
- interval = poll_interval(0);
- if (fabs(offset) >= STEP_THRESHOLD * 8 && interval > BIGOFF_INTERVAL) {
- /* If we are synced, offsets are less than STEP_THRESHOLD,
+ interval = poll_interval(INT_MAX);
+ if (fabs(offset) >= BIGOFF && interval > BIGOFF_INTERVAL) {
+ /* If we are synced, offsets are less than SLEW_THRESHOLD,
* or at the very least not much larger than it.
* Now we see a largish one.
* Either this peer is feeling bad, or packet got corrupted,
interval = BIGOFF_INTERVAL;
}
- set_next_and_ret:
set_next(p, interval);
}
goto bail;
}
+ /* Respond only to client and symmetric active packets */
+ if ((msg.m_status & MODE_MASK) != MODE_CLIENT
+ && (msg.m_status & MODE_MASK) != MODE_SYM_ACT
+ ) {
+ goto bail;
+ }
+
query_status = msg.m_status;
query_xmttime = msg.m_xmttime;
unsigned opts;
llist_t *peers;
- srandom(getpid());
+ srand(getpid());
if (getuid())
bb_error_msg_and_die(bb_msg_you_must_be_root);
/* Set some globals */
+ G.discipline_jitter = G_precision_sec;
G.stratum = MAXSTRAT;
if (BURSTPOLL != 0)
G.poll_exp = BURSTPOLL; /* speeds up initial sync */
/* Parse options */
peers = NULL;
- opt_complementary = "dd:p::wn"; /* d: counter; p: list; -w implies -n */
+ opt_complementary = "dd:wn" /* -d: counter; -p: list; -w implies -n */
+ IF_FEATURE_NTPD_SERVER(":Il"); /* -I implies -l */
opts = getopt32(argv,
"nqNx" /* compat */
- "wp:S:"IF_FEATURE_NTPD_SERVER("l") /* NOT compat */
+ "wp:*S:"IF_FEATURE_NTPD_SERVER("l") /* NOT compat */
+ IF_FEATURE_NTPD_SERVER("I:") /* compat */
"d" /* compat */
"46aAbgL", /* compat, ignored */
- &peers, &G.script_name, &G.verbose);
- if (!(opts & (OPT_p|OPT_l)))
- bb_show_usage();
+ &peers, &G.script_name,
+#if ENABLE_FEATURE_NTPD_SERVER
+ &G.if_name,
+#endif
+ &G.verbose);
+
// if (opts & OPT_x) /* disable stepping, only slew is allowed */
// G.time_was_stepped = 1;
- 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 ENABLE_FEATURE_NTPD_SERVER
G_listen_fd = -1;
if (opts & OPT_l) {
G_listen_fd = create_and_bind_dgram_or_die(NULL, 123);
+ if (G.if_name) {
+ if (setsockopt_bindtodevice(G_listen_fd, G.if_name))
+ xfunc_die();
+ }
socket_want_pktinfo(G_listen_fd);
- setsockopt(G_listen_fd, IPPROTO_IP, IP_TOS, &const_IPTOS_LOWDELAY, sizeof(const_IPTOS_LOWDELAY));
+ setsockopt_int(G_listen_fd, IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY);
}
#endif
/* I hesitate to set -20 prio. -15 should be high enough for timekeeping */
if (opts & OPT_N)
setpriority(PRIO_PROCESS, 0, -15);
+ if (!(opts & OPT_n)) {
+ bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO, argv);
+ logmode = LOGMODE_NONE;
+ }
+
+ if (peers) {
+ while (peers)
+ add_peers(llist_pop(&peers));
+ }
+#if ENABLE_FEATURE_NTPD_CONF
+ else {
+ parser_t *parser;
+ char *token[3];
+
+ parser = config_open("/etc/ntp.conf");
+ while (config_read(parser, token, 3, 1, "# \t", PARSE_NORMAL)) {
+ if (strcmp(token[0], "server") == 0 && token[1]) {
+ add_peers(token[1]);
+ continue;
+ }
+ bb_error_msg("skipping %s:%u: unimplemented command '%s'",
+ "/etc/ntp.conf", parser->lineno, token[0]
+ );
+ }
+ config_close(parser);
+ }
+#endif
+ if (G.peer_cnt == 0) {
+ if (!(opts & OPT_l))
+ bb_show_usage();
+ /* -l but no peers: "stratum 1 server" mode */
+ G.stratum = 1;
+ }
/* If network is up, syncronization occurs in ~10 seconds.
* We give "ntpd -q" 10 seconds to get first reply,
* then another 50 seconds to finish syncing.
if (p->p_fd == -1) {
/* Time to send new req */
if (--cnt == 0) {
- G.initial_poll_complete = 1;
+ VERB4 bb_error_msg("disabling burst mode");
+ G.polladj_count = 0;
+ G.poll_exp = MINPOLL;
}
send_query_to_peer(p);
} else {
/* Timed out waiting for reply */
close(p->p_fd);
p->p_fd = -1;
- timeout = poll_interval(-2); /* -2: try a bit sooner */
+ /* If poll interval is small, increase it */
+ if (G.poll_exp < BIGPOLL)
+ adjust_poll(MINPOLL);
+ timeout = poll_interval(NOREPLY_INTERVAL);
bb_error_msg("timed out waiting for %s, reach 0x%02x, next query in %us",
p->p_dotted, p->reachable_bits, timeout);
+
+ /* What if don't see it because it changed its IP? */
+ if (p->reachable_bits == 0)
+ resolve_peer_hostname(p);
+
set_next(p, timeout);
}
}
goto have_reachable_peer;
}
/* No peer responded for last 8 packets, panic */
- G.polladj_count = 0;
- G.poll_exp = MINPOLL;
- G.stratum = MAXSTRAT;
+ clamp_pollexp_and_set_MAXSTRAT();
run_script("unsync", 0.0);
have_reachable_peer: ;
}
projects / oweals / busybox.git / blobdiff