X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Fntpd.c;h=5cc71ca7a266479c76c638f0a5f6300be29a340b;hb=89193f985bf50af702e0f98a3c86573277c03287;hp=d4754f8bac71513ea73dd88bc22a082d91d82544;hpb=61313117a07fff81059376685dff3d61aaaf12b5;p=oweals%2Fbusybox.git diff --git a/networking/ntpd.c b/networking/ntpd.c index d4754f8ba..5cc71ca7a 100644 --- a/networking/ntpd.c +++ b/networking/ntpd.c @@ -1,85 +1,220 @@ /* * NTP client/server, based on OpenNTPD 3.9p1 * - * Author: Adam Tkac + * Busybox port author: Adam Tkac (C) 2009 * - * Licensed under GPLv2, see file LICENSE in this tarball for details. + * OpenNTPd 3.9p1 copyright holders: + * Copyright (c) 2003, 2004 Henning Brauer + * Copyright (c) 2004 Alexander Guy + * + * 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 -I IFACE")"] [-S PROG] [-p PEER]..." +//usage:#define ntpd_full_usage "\n\n" +//usage: "NTP client/server\n" +//usage: "\n -d Verbose" +//usage: "\n -n Do not daemonize" +//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: "\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 #include /* For IPTOS_LOWDELAY definition */ +#include /* setpriority */ #include #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). - * max 5 is very talkative (and bloated). 2 is non-bloated, + * max 6 is very talkative (and bloated). 3 is non-bloated, * production level setting. */ -#define MAX_VERBOSE 2 +#define MAX_VERBOSE 3 -#define RETRY_INTERVAL 5 /* on error, retry in N secs */ -#define QUERYTIME_MAX 15 /* wait for reply up to N secs */ +/* High-level description of the algorithm: + * + * We start running with very small poll_exp, BURSTPOLL, + * 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: + * we collect new datapoints but ignore them for WATCH_THRESHOLD + * seconds. After WATCH_THRESHOLD seconds we look at accumulated + * offset and estimate frequency drift. + * + * (frequency measurement step seems to not be strictly needed, + * it is conditionally disabled with USING_INITIAL_FREQ_ESTIMATION + * define set to 0) + * + * After this, we enter "steady state": we collect a datapoint, + * we select the best peer, if this datapoint is not a new one + * (IOW: if this datapoint isn't for selected peer), sleep + * and collect another one; otherwise, use its offset to update + * frequency drift, if offset is somewhat large, reduce poll_exp, + * otherwise increase poll_exp. + * + * If offset is larger than STEP_THRESHOLD, which shouldn't normally + * happen, we assume that something "bad" happened (computer + * was hibernated, someone set totally wrong date, etc), + * then the time is stepped, all datapoints are discarded, + * and we go back to steady state. + * + * Made some changes to speed up re-syncing after our clock goes bad + * (tested with suspending my laptop): + * - 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: + * e.g. at poll = 10 (1024 secs), step was done within 5 minutes + * after first reply which indicated that our clock is 14 seconds off. + * - on step, do not discard d_dispersion data of the existing datapoints, + * do not clear reachable_bits. This prevents discarding first ~8 + * datapoints after the step. + */ -#define FREQ_TOLERANCE 0.000015 /* % frequency tolerance (15 PPM) */ -#define MINPOLL 4 /* % minimum poll interval (6: 64 s) */ -#define MAXPOLL 12 /* % maximum poll interval (12: 1.1h, 17: 36.4h) (was 17) */ -#define MINDISP 0.01 /* % minimum dispersion (s) */ -#define MAXDISP 16 /* maximum dispersion (s) */ -#define MAXSTRAT 16 /* maximum stratum (infinity metric) */ -#define MAXDIST 1 /* % distance threshold (s) */ -#define MIN_SELECTED 1 /* % minimum intersection survivors */ -#define MIN_CLUSTERED 3 /* % minimum cluster survivors */ +#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 */ -#define MAXDRIFT 0.000500 /* frequency drift we can correct (500 PPM) */ +#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 */ -/* Clock discipline parameters and constants */ -#define STEP_THRESHOLD 0.128 /* step threshold (s) */ -#define WATCH_THRESHOLD 150 /* stepout threshold (s). std ntpd uses 900 (11 mins (!)) */ +/* Step threshold (sec). std ntpd uses 0.128. + */ +#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) */ -#define PANIC_THRESHOLD 1000 /* panic threshold (s) */ +//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 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 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 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) */ +#define MAXDIST 1 /* distance threshold (sec) */ +#define MIN_SELECTED 1 /* minimum intersection survivors */ +#define MIN_CLUSTERED 3 /* minimum cluster survivors */ + +#define MAXDRIFT 0.000500 /* frequency drift we can correct (500 PPM) */ /* Poll-adjust threshold. * When we see that offset is small enough compared to discipline jitter, - * we grow a counter: += MINPOLL. When it goes over POLLADJ_LIMIT, + * we grow a counter: += MINPOLL. When counter goes over POLLADJ_LIMIT, * we poll_exp++. If offset isn't small, counter -= poll_exp*2, - * and when it goes below -POLLADJ_LIMIT, we poll_exp-- + * and when it goes below -POLLADJ_LIMIT, we poll_exp--. + * (Bumped from 30 to 40 since otherwise I often see poll_exp going *2* steps down) */ -#define POLLADJ_LIMIT 30 -/* If offset < POLLADJ_GATE * discipline_jitter, then we can increase +#define POLLADJ_LIMIT 40 +/* If offset < discipline_jitter * POLLADJ_GATE, then we decide to increase * poll interval (we think we can't improve timekeeping * by staying at smaller poll). */ #define POLLADJ_GATE 4 -/* Compromise Allan intercept (s). doc uses 1500, std ntpd uses 512 */ +#define TIMECONST_HACK_GATE 2 +/* Compromise Allan intercept (sec). doc uses 1500, std ntpd uses 512 */ #define ALLAN 512 /* PLL loop gain */ #define PLL 65536 @@ -152,24 +287,27 @@ typedef struct { } msg_t; typedef struct { - double d_recv_time; double d_offset; + double d_recv_time; double d_dispersion; } datapoint_t; typedef struct { len_and_sockaddr *p_lsa; char *p_dotted; - /* when to send new query (if p_fd == -1) - * or when receive times out (if p_fd >= 0): */ - time_t next_action_time; int p_fd; int datapoint_idx; uint32_t lastpkt_refid; - uint8_t lastpkt_leap; + uint8_t lastpkt_status; uint8_t lastpkt_stratum; - uint8_t p_reachable_bits; + uint8_t reachable_bits; + /* when to send new query (if p_fd == -1) + * 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; @@ -181,9 +319,13 @@ typedef struct { datapoint_t filter_datapoint[NUM_DATAPOINTS]; /* last sent packet: */ msg_t p_xmt_msg; + char p_hostname[1]; } peer_t; +#define USING_KERNEL_PLL_LOOP 1 +#define USING_INITIAL_FREQ_ESTIMATION 0 + enum { OPT_n = (1 << 0), OPT_q = (1 << 1), @@ -191,89 +333,116 @@ enum { OPT_x = (1 << 3), /* Insert new options above this line. */ /* Non-compat options: */ - OPT_p = (1 << 4), - OPT_l = (1 << 5) * ENABLE_FEATURE_NTPD_SERVER, + OPT_w = (1 << 4), + 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), }; struct globals { + double cur_time; /* total round trip delay to currently selected reference clock */ double rootdelay; /* reference timestamp: time when the system clock was last set or corrected */ double reftime; /* total dispersion to currently selected reference clock */ double rootdisp; + + double last_script_run; + char *script_name; 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) #endif unsigned verbose; unsigned peer_cnt; /* refid: 32-bit code identifying the particular server or reference clock - * in stratum 0 packets this is a four-character ASCII string, - * called the kiss code, used for debugging and monitoring - * in stratum 1 packets this is a four-character ASCII string - * assigned to the reference clock by IANA. Example: "GPS " - * in stratum 2+ packets, it's IPv4 address or 4 first bytes of MD5 hash of IPv6 + * in stratum 0 packets this is a four-character ASCII string, + * called the kiss code, used for debugging and monitoring + * in stratum 1 packets this is a four-character ASCII string + * assigned to the reference clock by IANA. Example: "GPS " + * in stratum 2+ packets, it's IPv4 address or 4 first bytes + * of MD5 hash of IPv6 */ uint32_t refid; - uint8_t leap; + uint8_t ntp_status; /* precision is defined as the larger of the resolution and time to * read the clock, in log2 units. For instance, the precision of a * mains-frequency clock incrementing at 60 Hz is 16 ms, even when the * system clock hardware representation is to the nanosecond. * - * Delays, jitters of various kinds are clamper down to precision. + * Delays, jitters of various kinds are clamped down to precision. * * If precision_sec is too large, discipline_jitter gets clamped to it - * and if offset is much smaller than discipline_jitter, poll interval - * grows even though we really can benefit from staying at smaller one, - * collecting non-lagged datapoits and correcting the offset. + * and if offset is smaller than discipline_jitter * POLLADJ_GATE, poll + * interval grows even though we really can benefit from staying at + * smaller one, collecting non-lagged datapoits and correcting offset. * (Lagged datapoits exist when poll_exp is large but we still have * systematic offset error - the time distance between datapoints - * is significat and older datapoints have smaller offsets. + * is significant and older datapoints have smaller offsets. * This makes our offset estimation a bit smaller than reality) * Due to this effect, setting G_precision_sec close to * STEP_THRESHOLD isn't such a good idea - offsets may grow * too big and we will step. I observed it with -6. * - * OTOH, setting precision too small would result in futile attempts - * to syncronize to the unachievable precision. + * OTOH, setting precision_sec far too small would result in futile + * attempts to syncronize to an unachievable precision. * * -6 is 1/64 sec, -7 is 1/128 sec and so on. + * -8 is 1/256 ~= 0.003906 (worked well for me --vda) + * -9 is 1/512 ~= 0.001953 (let's try this for some time) + */ +#define G_precision_exp -9 + /* + * G_precision_exp is used only for construction outgoing packets. + * It's ok to set G_precision_sec to a slightly different value + * (One which is "nicer looking" in logs). + * Exact value would be (1.0 / (1 << (- G_precision_exp))): */ -#define G_precision_exp -8 -#define G_precision_sec (1.0 / (1 << (- G_precision_exp))) +#define G_precision_sec 0.002 uint8_t stratum; - /* Bool. After set to 1, never goes back to 0: */ -//TODO: fix logic: -// uint8_t time_was_stepped; - uint8_t adjtimex_was_done; +#define STATE_NSET 0 /* initial state, "nothing is set" */ +//#define STATE_FSET 1 /* frequency set from file */ +//#define STATE_SPIK 2 /* spike detected */ +//#define STATE_FREQ 3 /* initial frequency */ +#define STATE_SYNC 4 /* clock synchronized (normal operation) */ uint8_t discipline_state; // doc calls it c.state uint8_t poll_exp; // s.poll int polladj_count; // c.count long kernel_freq_drift; + peer_t *last_update_peer; double last_update_offset; // c.last double last_update_recv_time; // s.t double discipline_jitter; // c.jitter -//TODO: add s.jitter - grep for it here and see clock_combine() in doc -#define USING_KERNEL_PLL_LOOP 1 + /* Since we only compare it with ints, can simplify code + * by not making this variable floating point: + */ + unsigned offset_to_jitter_ratio; + //double cluster_offset; // s.offset + //double cluster_jitter; // s.jitter #if !USING_KERNEL_PLL_LOOP double discipline_freq_drift; // c.freq -//TODO: conditionally calculate wander? it's used only for logging + /* Maybe conditionally calculate wander? it's used only for logging */ double discipline_wander; // c.wander #endif }; #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) #define VERB3 if (MAX_VERBOSE >= 3 && G.verbose >= 3) #define VERB4 if (MAX_VERBOSE >= 4 && G.verbose >= 4) #define VERB5 if (MAX_VERBOSE >= 5 && G.verbose >= 5) +#define VERB6 if (MAX_VERBOSE >= 6 && G.verbose >= 6) static double LOG2D(int a) @@ -298,14 +467,53 @@ static ALWAYS_INLINE double MIND(double a, double b) return a; return b; } -#define SQRT(x) (sqrt(x)) +static NOINLINE double my_SQRT(double X) +{ + union { + float f; + int32_t i; + } v; + double invsqrt; + double Xhalf = X * 0.5; + + /* Fast and good approximation to 1/sqrt(X), black magic */ + v.f = X; + /*v.i = 0x5f3759df - (v.i >> 1);*/ + v.i = 0x5f375a86 - (v.i >> 1); /* - this constant is slightly better */ + invsqrt = v.f; /* better than 0.2% accuracy */ + + /* Refining it using Newton's method: x1 = x0 - f(x0)/f'(x0) + * f(x) = 1/(x*x) - X (f==0 when x = 1/sqrt(X)) + * f'(x) = -2/(x*x*x) + * f(x)/f'(x) = (X - 1/(x*x)) / (2/(x*x*x)) = X*x*x*x/2 - x/2 + * x1 = x0 - (X*x0*x0*x0/2 - x0/2) = 1.5*x0 - X*x0*x0*x0/2 = x0*(1.5 - (X/2)*x0*x0) + */ + invsqrt = invsqrt * (1.5 - Xhalf * invsqrt * invsqrt); /* ~0.05% accuracy */ + /* invsqrt = invsqrt * (1.5 - Xhalf * invsqrt * invsqrt); 2nd iter: ~0.0001% accuracy */ + /* With 4 iterations, more than half results will be exact, + * at 6th iterations result stabilizes with about 72% results exact. + * We are well satisfied with 0.05% accuracy. + */ + + return X * invsqrt; /* X * 1/sqrt(X) ~= sqrt(X) */ +} +static ALWAYS_INLINE double SQRT(double X) +{ + /* If this arch doesn't use IEEE 754 floats, fall back to using libm */ + if (sizeof(float) != 4) + return sqrt(X); + + /* This avoids needing libm, saves about 0.5k on x86-32 */ + return my_SQRT(X); +} static double gettime1900d(void) { struct timeval tv; gettimeofday(&tv, NULL); /* never fails */ - return (tv.tv_sec + 1.0e-6 * tv.tv_usec + OFFSET_1900_1970); + G.cur_time = tv.tv_sec + (1.0e-6 * tv.tv_usec) + OFFSET_1900_1970; + return G.cur_time; } static void @@ -357,13 +565,13 @@ d_to_sfp(double d) #endif static double -dispersion(const datapoint_t *dp, double t) +dispersion(const datapoint_t *dp) { - return dp->d_dispersion + FREQ_TOLERANCE * (t - dp->d_recv_time); + return dp->d_dispersion + FREQ_TOLERANCE * (G.cur_time - dp->d_recv_time); } static double -root_distance(peer_t *p, double t) +root_distance(peer_t *p) { /* The root synchronization distance is the maximum error due to * all causes of the local clock relative to the primary server. @@ -373,35 +581,51 @@ root_distance(peer_t *p, double t) return MAXD(MINDISP, p->lastpkt_rootdelay + p->lastpkt_delay) / 2 + p->lastpkt_rootdisp + p->filter_dispersion - + FREQ_TOLERANCE * (t - p->lastpkt_recv_time) + + FREQ_TOLERANCE * (G.cur_time - p->lastpkt_recv_time) + p->filter_jitter; } static void set_next(peer_t *p, unsigned t) { - p->next_action_time = time(NULL) + t; + p->next_action_time = G.cur_time + t; } /* * Peer clock filter and its helpers */ static void -filter_datapoints(peer_t *p, double t) +filter_datapoints(peer_t *p) { int i, idx; - double minoff, maxoff, wavg, sum, w; - double x = x; + double sum, wavg; + datapoint_t *fdp; - minoff = maxoff = p->filter_datapoint[0].d_offset; +#if 0 +/* Simulations have shown that use of *averaged* offset for p->filter_offset + * is in fact worse than simply using last received one: with large poll intervals + * (>= 2048) averaging code uses offset values which are outdated by hours, + * and time/frequency correction goes totally wrong when fed essentially bogus offsets. + */ + int got_newest; + double minoff, maxoff, w; + double x = x; /* for compiler */ + double oldest_off = oldest_off; + double oldest_age = oldest_age; + double newest_off = newest_off; + double newest_age = newest_age; + + fdp = p->filter_datapoint; + + minoff = maxoff = fdp[0].d_offset; for (i = 1; i < NUM_DATAPOINTS; i++) { - if (minoff > p->filter_datapoint[i].d_offset) - minoff = p->filter_datapoint[i].d_offset; - if (maxoff < p->filter_datapoint[i].d_offset) - maxoff = p->filter_datapoint[i].d_offset; + if (minoff > fdp[i].d_offset) + minoff = fdp[i].d_offset; + if (maxoff < fdp[i].d_offset) + maxoff = fdp[i].d_offset; } - idx = p->datapoint_idx; /* most recent datapoint */ + idx = p->datapoint_idx; /* most recent datapoint's index */ /* Average offset: * Drop two outliers and take weighted average of the rest: * most_recent/2 + older1/4 + older2/8 ... + older5/32 + older6/32 @@ -410,110 +634,210 @@ filter_datapoints(peer_t *p, double t) */ wavg = 0; w = 0.5; - // n-1 - // --- dispersion(i) - // filter_dispersion = \ ------------- - // / (i+1) - // --- 2 - // i=0 + /* n-1 + * --- dispersion(i) + * filter_dispersion = \ ------------- + * / (i+1) + * --- 2 + * i=0 + */ + got_newest = 0; sum = 0; for (i = 0; i < NUM_DATAPOINTS; i++) { - VERB4 { + VERB5 { bb_error_msg("datapoint[%d]: off:%f disp:%f(%f) age:%f%s", i, - p->filter_datapoint[idx].d_offset, - p->filter_datapoint[idx].d_dispersion, dispersion(&p->filter_datapoint[idx], t), - t - p->filter_datapoint[idx].d_recv_time, - (minoff == p->filter_datapoint[idx].d_offset || maxoff == p->filter_datapoint[idx].d_offset) + fdp[idx].d_offset, + fdp[idx].d_dispersion, dispersion(&fdp[idx]), + G.cur_time - fdp[idx].d_recv_time, + (minoff == fdp[idx].d_offset || maxoff == fdp[idx].d_offset) ? " (outlier by offset)" : "" ); } - sum += dispersion(&p->filter_datapoint[idx], t) / (2 << i); + sum += dispersion(&fdp[idx]) / (2 << i); - if (minoff == p->filter_datapoint[idx].d_offset) { - minoff -= 1; + if (minoff == fdp[idx].d_offset) { + minoff -= 1; /* so that we don't match it ever again */ } else - if (maxoff == p->filter_datapoint[idx].d_offset) { + if (maxoff == fdp[idx].d_offset) { maxoff += 1; } else { - x = p->filter_datapoint[idx].d_offset * w; + oldest_off = fdp[idx].d_offset; + oldest_age = G.cur_time - fdp[idx].d_recv_time; + if (!got_newest) { + got_newest = 1; + newest_off = oldest_off; + newest_age = oldest_age; + } + x = oldest_off * w; wavg += x; w /= 2; } idx = (idx - 1) & (NUM_DATAPOINTS - 1); } + p->filter_dispersion = sum; wavg += x; /* add another older6/64 to form older6/32 */ + /* Fix systematic underestimation with large poll intervals. + * Imagine that we still have a bit of uncorrected drift, + * and poll interval is big (say, 100 sec). Offsets form a progression: + * 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 - 0.7 is most recent. + * The algorithm above drops 0.0 and 0.7 as outliers, + * and then we have this estimation, ~25% off from 0.7: + * 0.1/32 + 0.2/32 + 0.3/16 + 0.4/8 + 0.5/4 + 0.6/2 = 0.503125 + */ + x = oldest_age - newest_age; + if (x != 0) { + x = newest_age / x; /* in above example, 100 / (600 - 100) */ + if (x < 1) { /* paranoia check */ + x = (newest_off - oldest_off) * x; /* 0.5 * 100/500 = 0.1 */ + wavg += x; + } + } p->filter_offset = wavg; + +#else + + fdp = p->filter_datapoint; + idx = p->datapoint_idx; /* most recent datapoint's index */ + + /* filter_offset: simply use the most recent value */ + p->filter_offset = fdp[idx].d_offset; + + /* n-1 + * --- dispersion(i) + * filter_dispersion = \ ------------- + * / (i+1) + * --- 2 + * i=0 + */ + wavg = 0; + sum = 0; + for (i = 0; i < NUM_DATAPOINTS; i++) { + sum += dispersion(&fdp[idx]) / (2 << i); + wavg += fdp[idx].d_offset; + idx = (idx - 1) & (NUM_DATAPOINTS - 1); + } + wavg /= NUM_DATAPOINTS; p->filter_dispersion = sum; +#endif - // +----- -----+ ^ 1/2 - // | n-1 | - // | --- | - // 1 | \ 2 | - // filter_jitter = --- * | / (avg-offset_j) | - // n | --- | - // | j=0 | - // +----- -----+ - // where n is the number of valid datapoints in the filter (n > 1); - // if filter_jitter < precision then filter_jitter = precision + /* +----- -----+ ^ 1/2 + * | n-1 | + * | --- | + * | 1 \ 2 | + * filter_jitter = | --- * / (avg-offset_j) | + * | n --- | + * | j=0 | + * +----- -----+ + * where n is the number of valid datapoints in the filter (n > 1); + * if filter_jitter < precision then filter_jitter = precision + */ sum = 0; for (i = 0; i < NUM_DATAPOINTS; i++) { - sum += SQUARE(wavg - p->filter_datapoint[i].d_offset); + sum += SQUARE(wavg - fdp[i].d_offset); } - sum = SQRT(sum) / NUM_DATAPOINTS; + sum = SQRT(sum / NUM_DATAPOINTS); p->filter_jitter = sum > G_precision_sec ? sum : G_precision_sec; - VERB3 bb_error_msg("filter offset:%f disp:%f jitter:%f", - p->filter_offset, p->filter_dispersion, p->filter_jitter); - + VERB4 bb_error_msg("filter offset:%+f disp:%f jitter:%f", + p->filter_offset, + p->filter_dispersion, + p->filter_jitter); } static void -reset_peer_stats(peer_t *p, double t, double offset) +reset_peer_stats(peer_t *p, double offset) { int i; + 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 suspending laptop for ~30 secs), + * this caused all previous data to be considered invalid, + * making us needing to collect full ~8 datapoints per peer + * after step in order to start trusting them. + * In turn, this was making poll interval decrease even after + * step was done. (Poll interval decreases already before step + * in this scenario, because we see large offsets and end up with + * no good peer to select). + */ + for (i = 0; i < NUM_DATAPOINTS; i++) { - if (offset < 16 * STEP_THRESHOLD) { - p->filter_datapoint[i].d_recv_time -= offset; + if (small_ofs) { + p->filter_datapoint[i].d_recv_time += offset; if (p->filter_datapoint[i].d_offset != 0) { p->filter_datapoint[i].d_offset -= offset; + //bb_error_msg("p->filter_datapoint[%d].d_offset %f -> %f", + // i, + // p->filter_datapoint[i].d_offset + offset, + // p->filter_datapoint[i].d_offset); } } else { - p->filter_datapoint[i].d_recv_time = t; + p->filter_datapoint[i].d_recv_time = G.cur_time; p->filter_datapoint[i].d_offset = 0; - p->filter_datapoint[i].d_dispersion = MAXDISP; + /*p->filter_datapoint[i].d_dispersion = MAXDISP;*/ } } - if (offset < 16 * STEP_THRESHOLD) { - p->lastpkt_recv_time -= offset; + if (small_ofs) { + p->lastpkt_recv_time += offset; + } else { + /*p->reachable_bits = 0;*/ + p->lastpkt_recv_time = G.cur_time; + } + filter_datapoints(p); /* recalc p->filter_xxx */ + 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); + VERB1 if (strcmp(p->p_hostname, p->p_dotted) != 0) + bb_error_msg("'%s' is %s", p->p_hostname, p->p_dotted); } else { - p->p_reachable_bits = 0; - p->lastpkt_recv_time = t; + /* error message is emitted by host2sockaddr() */ + set_next(p, HOSTNAME_INTERVAL); } - filter_datapoints(p, t); /* recalc p->filter_xxx */ - p->next_action_time -= (time_t)offset; - VERB5 bb_error_msg("%s->lastpkt_recv_time=%f", p->p_dotted, p->lastpkt_recv_time); + 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 = time(NULL); /* = set_next(p, 0); */ - reset_peer_stats(p, gettime1900d(), 16 * STEP_THRESHOLD); - /* Speed up initial sync: with small offsets from peers, - * 3 samples will sync + p->next_action_time = G.cur_time; /* = set_next(p, 0); */ + reset_peer_stats(p, STEP_THRESHOLD); + + /* Names like N..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. */ - p->filter_datapoint[6].d_dispersion = 0; - p->filter_datapoint[7].d_dispersion = 0; + 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++; @@ -539,25 +863,31 @@ do_sendto(int fd, return 0; } -static int +static void send_query_to_peer(peer_t *p) { - // Why do we need to bind()? - // See what happens when we don't bind: - // - // socket(PF_INET, SOCK_DGRAM, IPPROTO_IP) = 3 - // setsockopt(3, SOL_IP, IP_TOS, [16], 4) = 0 - // gettimeofday({1259071266, 327885}, NULL) = 0 - // sendto(3, "xxx", 48, MSG_DONTWAIT, {sa_family=AF_INET, sin_port=htons(123), sin_addr=inet_addr("10.34.32.125")}, 16) = 48 - // ^^^ we sent it from some source port picked by kernel. - // time(NULL) = 1259071266 - // write(2, "ntpd: entering poll 15 secs\n", 28) = 28 - // poll([{fd=3, events=POLLIN}], 1, 15000) = 1 ([{fd=3, revents=POLLIN}]) - // recv(3, "yyy", 68, MSG_DONTWAIT) = 48 - // ^^^ this recv will receive packets to any local port! - // - // Uncomment this and use strace to see it in action: -#define PROBE_LOCAL_ADDR // { len_and_sockaddr lsa; lsa.len = LSA_SIZEOF_SA; getsockname(p->query.fd, &lsa.u.sa, &lsa.len); } + if (!p->p_lsa) { + if (!resolve_peer_hostname(p)) + return; + } + + /* Why do we need to bind()? + * See what happens when we don't bind: + * + * socket(PF_INET, SOCK_DGRAM, IPPROTO_IP) = 3 + * setsockopt(3, SOL_IP, IP_TOS, [16], 4) = 0 + * gettimeofday({1259071266, 327885}, NULL) = 0 + * sendto(3, "xxx", 48, MSG_DONTWAIT, {sa_family=AF_INET, sin_port=htons(123), sin_addr=inet_addr("10.34.32.125")}, 16) = 48 + * ^^^ we sent it from some source port picked by kernel. + * time(NULL) = 1259071266 + * write(2, "ntpd: entering poll 15 secs\n", 28) = 28 + * poll([{fd=3, events=POLLIN}], 1, 15000) = 1 ([{fd=3, revents=POLLIN}]) + * recv(3, "yyy", 68, MSG_DONTWAIT) = 48 + * ^^^ this recv will receive packets to any local port! + * + * Uncomment this and use strace to see it in action: + */ +#define PROBE_LOCAL_ADDR /* { len_and_sockaddr lsa; lsa.len = LSA_SIZEOF_SA; getsockname(p->query.fd, &lsa.u.sa, &lsa.len); } */ if (p->p_fd == -1) { int fd, family; @@ -576,10 +906,16 @@ send_query_to_peer(peer_t *p) #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); } + /* Emit message _before_ attempted send. Think of a very short + * roundtrip networks: we need to go back to recv loop ASAP, + * to reduce delay. Printing messages after send works against that. + */ + VERB1 bb_error_msg("sending query to %s", p->p_dotted); + /* * Send out a random 64-bit number as our transmit time. The NTP * server will copy said number into the originate field on the @@ -593,49 +929,146 @@ send_query_to_peer(peer_t *p) * * 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 + * loss of sync detection needs reachable_bits updated + * even if sending fails *locally*: + * "network is unreachable" because cable was pulled? + * We still need to declare "unsync" if this condition persists. + */ + p->reachable_bits <<= 1; + if (do_sendto(p->p_fd, /*from:*/ NULL, /*to:*/ &p->p_lsa->u.sa, /*addrlen:*/ p->p_lsa->len, &p->p_xmt_msg, NTP_MSGSIZE_NOAUTH) == -1 ) { close(p->p_fd); p->p_fd = -1; + /* + * We know that we sent nothing. + * We can retry *soon* without fearing + * that we are flooding the peer. + */ set_next(p, RETRY_INTERVAL); - return -1; + return; } - p->p_reachable_bits <<= 1; - VERB1 bb_error_msg("sent query to %s", p->p_dotted); - set_next(p, QUERYTIME_MAX); - - return 0; + set_next(p, RESPONSE_INTERVAL); } -static void +/* Note that there is no provision to prevent several run_scripts + * to be started 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]; + char *env1, *env2, *env3, *env4; + + G.last_script_run = G.cur_time; + + if (!G.script_name) + return; + + argv[0] = (char*) G.script_name; + argv[1] = (char*) action; + argv[2] = NULL; + + VERB1 bb_error_msg("executing '%s %s'", G.script_name, action); + + env1 = xasprintf("%s=%u", "stratum", G.stratum); + putenv(env1); + env2 = xasprintf("%s=%ld", "freq_drift_ppm", G.kernel_freq_drift); + putenv(env2); + env3 = xasprintf("%s=%u", "poll_interval", 1 << G.poll_exp); + putenv(env3); + env4 = xasprintf("%s=%f", "offset", offset); + putenv(env4); + /* Other items of potential interest: selected peer, + * rootdelay, reftime, rootdisp, refid, ntp_status, + * last_update_offset, last_update_recv_time, discipline_jitter, + * how many peers have reachable_bits = 0? + */ + + /* Don't want to wait: it may run hwclock --systohc, and that + * may take some time (seconds): */ + /*spawn_and_wait(argv);*/ + spawn(argv); + + unsetenv("stratum"); + unsetenv("freq_drift_ppm"); + unsetenv("poll_interval"); + unsetenv("offset"); + free(env1); + free(env2); + free(env3); + free(env4); +} + +static NOINLINE void step_time(double offset) { + llist_t *item; double dtime; - struct timeval tv; - char buf[80]; + struct timeval tvc, tvn; + char buf[sizeof("yyyy-mm-dd hh:mm:ss") + /*paranoia:*/ 4]; time_t tval; - gettimeofday(&tv, NULL); /* never fails */ - dtime = offset + tv.tv_sec; - dtime += 1.0e-6 * tv.tv_usec; - d_to_tv(dtime, &tv); - - if (settimeofday(&tv, NULL) == -1) + gettimeofday(&tvc, NULL); /* never fails */ + dtime = tvc.tv_sec + (1.0e-6 * tvc.tv_usec) + offset; + d_to_tv(dtime, &tvn); + if (settimeofday(&tvn, NULL) == -1) bb_perror_msg_and_die("settimeofday"); - tval = tv.tv_sec; - strftime(buf, sizeof(buf), "%a %b %e %H:%M:%S %Z %Y", localtime(&tval)); - - bb_error_msg("setting clock to %s (offset %fs)", buf, offset); + VERB2 { + tval = tvc.tv_sec; + strftime_YYYYMMDDHHMMSS(buf, sizeof(buf), &tval); + bb_error_msg("current time is %s.%06u", buf, (unsigned)tvc.tv_usec); + } + tval = tvn.tv_sec; + strftime_YYYYMMDDHHMMSS(buf, sizeof(buf), &tval); + bb_error_msg("setting time to %s.%06u (offset %+fs)", buf, (unsigned)tvn.tv_usec, offset); + + /* Correct various fields which contain time-relative values: */ + + /* Globals: */ + G.cur_time += offset; + G.last_update_recv_time += offset; + G.last_script_run += offset; + + /* p->lastpkt_recv_time, p->next_action_time and such: */ + 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; + if (pp->p_fd >= 0) { + /* We wait for reply from this peer too. + * But due to step we are doing, reply's data is no longer + * useful (in fact, it'll be bogus). Stop waiting for it. + */ + close(pp->p_fd); + pp->p_fd = -1; + set_next(pp, RETRY_INTERVAL); + } + } +} -// G.time_was_stepped = 1; +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; } @@ -646,6 +1079,7 @@ typedef struct { peer_t *p; int type; double edge; + double opt_rd; /* optimization */ } point_t; static int compare_point_edge(const void *aa, const void *bb) @@ -666,38 +1100,42 @@ compare_survivor_metric(const void *aa, const void *bb) { const survivor_t *a = aa; const survivor_t *b = bb; - if (a->metric < b->metric) + if (a->metric < b->metric) { return -1; + } return (a->metric > b->metric); } static int fit(peer_t *p, double rd) { - if (p->p_reachable_bits == 0) { - VERB3 bb_error_msg("peer %s unfit for selection: unreachable", p->p_dotted); + if ((p->reachable_bits & (p->reachable_bits-1)) == 0) { + /* One or zero bits in reachable_bits */ + VERB4 bb_error_msg("peer %s unfit for selection: unreachable", p->p_dotted); return 0; } -//TODO: we never accept such packets anyway, right? - if ((p->lastpkt_leap & LI_ALARM) == LI_ALARM +#if 0 /* we filter out such packets earlier */ + if ((p->lastpkt_status & LI_ALARM) == LI_ALARM || p->lastpkt_stratum >= MAXSTRAT ) { - VERB3 bb_error_msg("peer %s unfit for selection: bad status/stratum", p->p_dotted); + VERB4 bb_error_msg("peer %s unfit for selection: bad status/stratum", p->p_dotted); return 0; } - /* rd is root_distance(p, t) */ +#endif + /* rd is root_distance(p) */ if (rd > MAXDIST + FREQ_TOLERANCE * (1 << G.poll_exp)) { - VERB3 bb_error_msg("peer %s unfit for selection: root distance too high", p->p_dotted); + VERB4 bb_error_msg("peer %s unfit for selection: root distance too high", p->p_dotted); return 0; } //TODO // /* Do we have a loop? */ // if (p->refid == p->dstaddr || p->refid == s.refid) // return 0; - return 1; + return 1; } static peer_t* -select_and_cluster(double t) +select_and_cluster(void) { + peer_t *p; llist_t *item; int i, j; int size = 3 * G.peer_cnt; @@ -715,16 +1153,17 @@ select_and_cluster(double t) num_points = 0; item = G.ntp_peers; while (item != NULL) { - peer_t *p = (peer_t *) item->data; - double rd = root_distance(p, t); - double offset = p->filter_offset; + double rd, offset; + p = (peer_t *) item->data; + rd = root_distance(p); + offset = p->filter_offset; if (!fit(p, rd)) { item = item->link; continue; } - VERB4 bb_error_msg("interval: [%f %f %f] %s", + VERB5 bb_error_msg("interval: [%f %f %f] %s", offset - rd, offset, offset + rd, @@ -733,21 +1172,24 @@ select_and_cluster(double t) point[num_points].p = p; point[num_points].type = -1; point[num_points].edge = offset - rd; + point[num_points].opt_rd = rd; num_points++; point[num_points].p = p; point[num_points].type = 0; point[num_points].edge = offset; + point[num_points].opt_rd = rd; num_points++; point[num_points].p = p; point[num_points].type = 1; point[num_points].edge = offset + rd; + point[num_points].opt_rd = rd; num_points++; item = item->link; } num_candidates = num_points / 3; if (num_candidates == 0) { - VERB3 bb_error_msg("no valid datapoints, no peer selected"); - return NULL; /* never happers? */ + VERB3 bb_error_msg("no valid datapoints%s", ", no peer selected"); + return NULL; } //TODO: sorting does not seem to be done in reference code qsort(point, num_points, sizeof(point[0]), compare_point_edge); @@ -804,12 +1246,13 @@ select_and_cluster(double t) break; num_falsetickers++; if (num_falsetickers * 2 >= num_candidates) { - VERB3 bb_error_msg("too many falsetickers:%d (candidates:%d), no peer selected", - num_falsetickers, num_candidates); + VERB3 bb_error_msg("falsetickers:%d, candidates:%d%s", + num_falsetickers, num_candidates, + ", no peer selected"); return NULL; } } - VERB3 bb_error_msg("selected interval: [%f, %f]; candidates:%d falsetickers:%d", + VERB4 bb_error_msg("selected interval: [%f, %f]; candidates:%d falsetickers:%d", low, high, num_candidates, num_falsetickers); /* Clustering */ @@ -821,15 +1264,13 @@ select_and_cluster(double t) */ num_survivors = 0; for (i = 0; i < num_points; i++) { - peer_t *p; - if (point[i].edge < low || point[i].edge > high) continue; p = point[i].p; survivor[num_survivors].p = p; -//TODO: save root_distance in point_t and reuse here? - survivor[num_survivors].metric = MAXDIST * p->lastpkt_stratum + root_distance(p, t); - VERB4 bb_error_msg("survivor[%d] metric:%f peer:%s", + /* x.opt_rd == root_distance(p); */ + survivor[num_survivors].metric = MAXDIST * p->lastpkt_stratum + point[i].opt_rd; + VERB5 bb_error_msg("survivor[%d] metric:%f peer:%s", num_survivors, survivor[num_survivors].metric, p->p_dotted); num_survivors++; } @@ -839,8 +1280,9 @@ select_and_cluster(double t) * is acceptable. */ if (num_survivors < MIN_SELECTED) { - VERB3 bb_error_msg("num_survivors %d < %d, no peer selected", - num_survivors, MIN_SELECTED); + VERB3 bb_error_msg("survivors:%d%s", + num_survivors, + ", no peer selected"); return NULL; } @@ -860,7 +1302,7 @@ select_and_cluster(double t) double min_jitter = min_jitter; if (num_survivors <= MIN_CLUSTERED) { - bb_error_msg("num_survivors %d <= %d, not discarding more", + VERB4 bb_error_msg("num_survivors %d <= %d, not discarding more", num_survivors, MIN_CLUSTERED); break; } @@ -872,26 +1314,25 @@ select_and_cluster(double t) */ for (i = 0; i < num_survivors; i++) { double selection_jitter_sq; - peer_t *p = survivor[i].p; + p = survivor[i].p; if (i == 0 || p->filter_jitter < min_jitter) min_jitter = p->filter_jitter; selection_jitter_sq = 0; for (j = 0; j < num_survivors; j++) { peer_t *q = survivor[j].p; -//TODO: where is 1/(n-1) * ... multiplier? selection_jitter_sq += SQUARE(p->filter_offset - q->filter_offset); } if (i == 0 || selection_jitter_sq > max_selection_jitter) { max_selection_jitter = selection_jitter_sq; max_idx = i; } - VERB5 bb_error_msg("survivor %d selection_jitter^2:%f", + VERB6 bb_error_msg("survivor %d selection_jitter^2:%f", i, selection_jitter_sq); } - max_selection_jitter = SQRT(max_selection_jitter); - VERB4 bb_error_msg("max_selection_jitter (at %d):%f min_jitter:%f", + max_selection_jitter = SQRT(max_selection_jitter / num_survivors); + VERB5 bb_error_msg("max_selection_jitter (at %d):%f min_jitter:%f", max_idx, max_selection_jitter, min_jitter); /* If the maximum selection jitter is less than the @@ -900,7 +1341,7 @@ select_and_cluster(double t) * as well stop. */ if (max_selection_jitter < min_jitter) { - VERB3 bb_error_msg("max_selection_jitter:%f < min_jitter:%f, num_survivors:%d, not discarding more", + VERB4 bb_error_msg("max_selection_jitter:%f < min_jitter:%f, num_survivors:%d, not discarding more", max_selection_jitter, min_jitter, num_survivors); break; } @@ -908,7 +1349,7 @@ select_and_cluster(double t) /* Delete survivor[max_idx] from the list * and go around again. */ - VERB5 bb_error_msg("dropping survivor %d", max_idx); + VERB6 bb_error_msg("dropping survivor %d", max_idx); num_survivors--; while (max_idx < num_survivors) { survivor[max_idx] = survivor[max_idx + 1]; @@ -916,18 +1357,54 @@ select_and_cluster(double t) } } + if (0) { + /* Combine the offsets of the clustering algorithm survivors + * using a weighted average with weight determined by the root + * distance. Compute the selection jitter as the weighted RMS + * difference between the first survivor and the remaining + * survivors. In some cases the inherent clock jitter can be + * reduced by not using this algorithm, especially when frequent + * clockhopping is involved. bbox: thus we don't do it. + */ + double x, y, z, w; + y = z = w = 0; + for (i = 0; i < num_survivors; i++) { + p = survivor[i].p; + x = root_distance(p); + y += 1 / x; + z += p->filter_offset / x; + w += SQUARE(p->filter_offset - survivor[0].p->filter_offset) / x; + } + //G.cluster_offset = z / y; + //G.cluster_jitter = SQRT(w / y); + } + /* Pick the best clock. If the old system peer is on the list * and at the same stratum as the first survivor on the list, * then don't do a clock hop. Otherwise, select the first * survivor on the list as the new system peer. */ -//TODO - see clock_combine() - VERB3 bb_error_msg("selected peer %s filter_offset:%f age:%f", - survivor[0].p->p_dotted, - survivor[0].p->filter_offset, - t - survivor[0].p->lastpkt_recv_time + p = survivor[0].p; + if (G.last_update_peer + && G.last_update_peer->lastpkt_stratum <= p->lastpkt_stratum + ) { + /* Starting from 1 is ok here */ + for (i = 1; i < num_survivors; i++) { + if (G.last_update_peer == survivor[i].p) { + VERB5 bb_error_msg("keeping old synced peer"); + p = G.last_update_peer; + goto keep_old; + } + } + } + G.last_update_peer = p; + keep_old: + VERB4 bb_error_msg("selected peer %s filter_offset:%+f age:%f", + p->p_dotted, + p->filter_offset, + G.cur_time - p->lastpkt_recv_time ); - return survivor[0].p; + return p; } @@ -941,46 +1418,48 @@ set_new_values(int disc_state, double offset, double recv_time) * of the last clock filter sample, which must be earlier than * the current time. */ - VERB3 bb_error_msg("disc_state=%d last_update_offset=%f last_update_recv_time=%f", + VERB4 bb_error_msg("disc_state=%d last update offset=%f recv_time=%f", disc_state, offset, recv_time); G.discipline_state = disc_state; G.last_update_offset = offset; G.last_update_recv_time = recv_time; } -/* Clock state definitions */ -#define STATE_NSET 0 /* initial state, "nothing is set" */ -#define STATE_FSET 1 /* frequency set from file */ -#define STATE_SPIK 2 /* spike detected */ -#define STATE_FREQ 3 /* initial frequency */ -#define STATE_SYNC 4 /* clock synchronized (normal operation) */ /* Return: -1: decrease poll interval, 0: leave as is, 1: increase */ -static int -update_local_clock(peer_t *p, double t) +static NOINLINE int +update_local_clock(peer_t *p) { int rc; - long old_tmx_offset; struct timex tmx; + /* Note: can use G.cluster_offset instead: */ double offset = p->filter_offset; double recv_time = p->lastpkt_recv_time; double abs_offset; +#if !USING_KERNEL_PLL_LOOP double freq_drift; +#endif +#if !USING_KERNEL_PLL_LOOP || USING_INITIAL_FREQ_ESTIMATION double since_last_update; +#endif double etemp, dtemp; abs_offset = fabs(offset); +#if 0 + /* 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); } +#endif /* If this is an old update, for instance as the result * of a system peer change, avoid it. We never use * an old sample or the same sample twice. */ if (recv_time <= G.last_update_recv_time) { - VERB3 bb_error_msg("same or older datapoint: %f >= %f, not using it", - G.last_update_recv_time, recv_time); + VERB3 bb_error_msg("update from %s: same or older datapoint, not using it", + p->p_dotted); return 0; /* "leave poll interval as is" */ } @@ -988,28 +1467,45 @@ update_local_clock(peer_t *p, double t) * action is and defines how the system reacts to large time * and frequency errors. */ +#if !USING_KERNEL_PLL_LOOP || USING_INITIAL_FREQ_ESTIMATION since_last_update = recv_time - G.reftime; +#endif +#if !USING_KERNEL_PLL_LOOP freq_drift = 0; +#endif +#if USING_INITIAL_FREQ_ESTIMATION if (G.discipline_state == STATE_FREQ) { /* Ignore updates until the stepout threshold */ if (since_last_update < WATCH_THRESHOLD) { - VERB3 bb_error_msg("measuring drift, datapoint ignored, %f sec remains", + VERB4 bb_error_msg("measuring drift, datapoint ignored, %f sec remains", WATCH_THRESHOLD - since_last_update); return 0; /* "leave poll interval as is" */ } +# if !USING_KERNEL_PLL_LOOP freq_drift = (offset - G.last_update_offset) / since_last_update; +# endif } +#endif /* There are two main regimes: when the * offset exceeds the step threshold and when it does not. */ if (abs_offset > STEP_THRESHOLD) { - llist_t *item; - +#if 0 + double remains; + +// This "spike state" seems to be useless, peer selection already drops +// occassional "bad" datapoints. If we are here, there were _many_ +// large offsets. When a few first large offsets are seen, +// we end up in "no valid datapoints, no peer selected" state. +// Only when enough of them are seen (which means it's not a fluke), +// we end up here. Looks like _our_ clock is off. switch (G.discipline_state) { case STATE_SYNC: /* The first outlyer: ignore it, switch to SPIK state */ - VERB3 bb_error_msg("offset:%f - spike detected", offset); + VERB3 bb_error_msg("update from %s: offset:%+f, spike%s", + p->p_dotted, offset, + ""); G.discipline_state = STATE_SPIK; return -1; /* "decrease poll interval" */ @@ -1017,13 +1513,16 @@ update_local_clock(peer_t *p, double t) /* Ignore succeeding outlyers until either an inlyer * is found or the stepout threshold is exceeded. */ - if (since_last_update < WATCH_THRESHOLD) { - VERB3 bb_error_msg("spike detected, datapoint ignored, %f sec remains", - WATCH_THRESHOLD - since_last_update); + remains = WATCH_THRESHOLD - since_last_update; + if (remains > 0) { + VERB3 bb_error_msg("update from %s: offset:%+f, spike%s", + p->p_dotted, offset, + ", datapoint ignored"); return -1; /* "decrease poll interval" */ } /* fall through: we need to step */ } /* switch */ +#endif /* Step the time and clamp down the poll interval. * @@ -1046,40 +1545,42 @@ update_local_clock(peer_t *p, double t) * is always suppressed, even at the longer poll * intervals. */ - VERB3 bb_error_msg("stepping time by %f; poll_exp=MINPOLL", offset); + VERB4 bb_error_msg("stepping time by %+f; poll_exp=MINPOLL", offset); step_time(offset); if (option_mask32 & OPT_q) { /* We were only asked to set time once. Done. */ exit(0); } - G.polladj_count = 0; - G.poll_exp = MINPOLL; - G.stratum = MAXSTRAT; - for (item = G.ntp_peers; item != NULL; item = item->link) { - peer_t *pp = (peer_t *) item->data; - reset_peer_stats(pp, t, offset); - } + clamp_pollexp_and_set_MAXSTRAT(); + + run_script("step", offset); + + recv_time += offset; + +#if USING_INITIAL_FREQ_ESTIMATION if (G.discipline_state == STATE_NSET) { set_new_values(STATE_FREQ, /*offset:*/ 0, recv_time); return 1; /* "ok to increase poll interval" */ } - set_new_values(STATE_SYNC, /*offset:*/ 0, recv_time); - +#endif + abs_offset = offset = 0; + set_new_values(STATE_SYNC, offset, recv_time); } else { /* abs_offset <= STEP_THRESHOLD */ - if (G.poll_exp < MINPOLL) { - VERB3 bb_error_msg("saw small offset %f, disabling burst mode", offset); - 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(MAXD(fabs(offset - G.last_update_offset), G_precision_sec)); + dtemp = SQUARE(offset - G.last_update_offset); G.discipline_jitter = SQRT(etemp + (dtemp - etemp) / AVG); - VERB3 bb_error_msg("discipline jitter=%f", G.discipline_jitter); + if (G.discipline_jitter < G_precision_sec) + G.discipline_jitter = G_precision_sec; switch (G.discipline_state) { case STATE_NSET: @@ -1089,13 +1590,17 @@ update_local_clock(peer_t *p, double t) */ exit(0); } +#if USING_INITIAL_FREQ_ESTIMATION /* This is the first update received and the frequency * has not been initialized. The first thing to do * is directly measure the oscillator frequency. */ set_new_values(STATE_FREQ, offset, recv_time); - VERB3 bb_error_msg("transitioning to FREQ, datapoint ignored"); - return -1; /* "decrease poll interval" */ +#else + set_new_values(STATE_SYNC, offset, recv_time); +#endif + VERB4 bb_error_msg("transitioning to FREQ, datapoint ignored"); + return 0; /* "leave poll interval as is" */ #if 0 /* this is dead code for now */ case STATE_FSET: @@ -1108,6 +1613,7 @@ update_local_clock(peer_t *p, double t) break; #endif +#if USING_INITIAL_FREQ_ESTIMATION case STATE_FREQ: /* since_last_update >= WATCH_THRESHOLD, we waited enough. * Correct the phase and frequency and switch to SYNC state. @@ -1115,8 +1621,10 @@ update_local_clock(peer_t *p, double t) */ set_new_values(STATE_SYNC, offset, recv_time); break; +#endif default: +#if !USING_KERNEL_PLL_LOOP /* Compute freq_drift due to PLL and FLL contributions. * * The FLL and PLL frequency gain constants @@ -1139,24 +1647,28 @@ update_local_clock(peer_t *p, double t) etemp = MIND(since_last_update, (1 << G.poll_exp)); dtemp = (4 * PLL) << G.poll_exp; freq_drift += offset * etemp / SQUARE(dtemp); +#endif set_new_values(STATE_SYNC, offset, recv_time); break; } - G.stratum = p->lastpkt_stratum + 1; + if (G.stratum != p->lastpkt_stratum + 1) { + G.stratum = p->lastpkt_stratum + 1; + run_script("stratum", offset); + } } - G.reftime = t; - G.leap = p->lastpkt_leap; + G.reftime = G.cur_time; + G.ntp_status = p->lastpkt_status; G.refid = p->lastpkt_refid; G.rootdelay = p->lastpkt_rootdelay + p->lastpkt_delay; - dtemp = p->filter_jitter; // SQRT(SQUARE(p->filter_jitter) + SQUARE(s.jitter)); - dtemp += MAXD(p->filter_dispersion + FREQ_TOLERANCE * (t - p->lastpkt_recv_time) + abs_offset, MINDISP); + dtemp = p->filter_jitter; // SQRT(SQUARE(p->filter_jitter) + SQUARE(G.cluster_jitter)); + dtemp += MAXD(p->filter_dispersion + FREQ_TOLERANCE * (G.cur_time - p->lastpkt_recv_time) + abs_offset, MINDISP); G.rootdisp = p->lastpkt_rootdisp + dtemp; - VERB3 bb_error_msg("updating leap/refid/reftime/rootdisp from peer %s", p->p_dotted); + VERB4 bb_error_msg("updating leap/refid/reftime/rootdisp from peer %s", p->p_dotted); /* We are in STATE_SYNC now, but did not do adjtimex yet. * (Any other state does not reach this, they all return earlier) - * By this time, freq_drift and G.last_update_offset are set + * By this time, freq_drift and offset are set * to values suitable for adjtimex. */ #if !USING_KERNEL_PLL_LOOP @@ -1172,31 +1684,20 @@ update_local_clock(peer_t *p, double t) dtemp = SQUARE(dtemp); G.discipline_wander = SQRT(etemp + (dtemp - etemp) / AVG); - VERB3 bb_error_msg("discipline freq_drift=%.9f(int:%ld corr:%e) wander=%f", + VERB4 bb_error_msg("discipline freq_drift=%.9f(int:%ld corr:%e) wander=%f", G.discipline_freq_drift, (long)(G.discipline_freq_drift * 65536e6), freq_drift, G.discipline_wander); #endif - VERB3 { + VERB4 { memset(&tmx, 0, sizeof(tmx)); if (adjtimex(&tmx) < 0) bb_perror_msg_and_die("adjtimex"); - VERB3 bb_error_msg("p adjtimex freq:%ld offset:%ld constant:%ld status:0x%x", - tmx.freq, tmx.offset, tmx.constant, tmx.status); + bb_error_msg("p adjtimex freq:%ld offset:%+ld status:0x%x tc:%ld", + tmx.freq, tmx.offset, tmx.status, tmx.constant); } - old_tmx_offset = 0; - if (!G.adjtimex_was_done) { - G.adjtimex_was_done = 1; - /* When we use adjtimex for the very first time, - * we need to ADD to pre-existing tmx.offset - it may be !0 - */ - memset(&tmx, 0, sizeof(tmx)); - if (adjtimex(&tmx) < 0) - bb_perror_msg_and_die("adjtimex"); - old_tmx_offset = tmx.offset; - } memset(&tmx, 0, sizeof(tmx)); #if 0 //doesn't work, offset remains 0 (!) in kernel: @@ -1206,61 +1707,60 @@ update_local_clock(peer_t *p, double t) tmx.modes = ADJ_FREQUENCY | ADJ_OFFSET; /* 65536 is one ppm */ tmx.freq = G.discipline_freq_drift * 65536e6; - tmx.offset = G.last_update_offset * 1000000; /* usec */ #endif tmx.modes = ADJ_OFFSET | ADJ_STATUS | ADJ_TIMECONST;// | ADJ_MAXERROR | ADJ_ESTERROR; - tmx.offset = (G.last_update_offset * 1000000) /* usec */ - /* + (G.last_update_offset < 0 ? -0.5 : 0.5) - too small to bother */ - + old_tmx_offset; /* almost always 0 */ + 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 + * tmx.freq in response to clock offset. Offset keeps growing + * and eventually we fall back to smaller poll intervals. + * We can make correction more agressive (about x2) by supplying + * PLL time constant which is one less than the real one. + * To be on a safe side, let's do it only if offset is significantly + * larger than jitter. + */ + 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 (sys_leap == LEAP_ADDSECOND) - // tmx.status |= STA_INS; - //else if (sys_leap == LEAP_DELSECOND) - // tmx.status |= STA_DEL; - tmx.constant = G.poll_exp - 4; - //tmx.esterror = (u_int32)(clock_jitter * 1e6); - //tmx.maxerror = (u_int32)((sys_rootdelay / 2 + sys_rootdisp) * 1e6); - VERB3 bb_error_msg("b adjtimex freq:%ld offset:%ld constant:%ld status:0x%x", - tmx.freq, tmx.offset, tmx.constant, tmx.status); + 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); rc = adjtimex(&tmx); if (rc < 0) bb_perror_msg_and_die("adjtimex"); - if (G.kernel_freq_drift != tmx.freq / 65536) { - G.kernel_freq_drift = tmx.freq / 65536; - VERB2 bb_error_msg("kernel clock drift: %ld ppm", G.kernel_freq_drift); - } - VERB3 { - bb_error_msg("adjtimex:%d freq:%ld offset:%ld constant:%ld status:0x%x", - rc, tmx.freq, tmx.offset, tmx.constant, tmx.status); -#if 0 - /* always gives the same output as above msg */ - memset(&tmx, 0, sizeof(tmx)); - if (adjtimex(&tmx) < 0) - bb_perror_msg_and_die("adjtimex"); - VERB3 bb_error_msg("c adjtimex freq:%ld offset:%ld constant:%ld status:0x%x", - tmx.freq, tmx.offset, tmx.constant, tmx.status); -#endif - } -// #define STA_MODE 0x4000 /* mode (0 = PLL, 1 = FLL) (ro) */ - ? -// it appeared after a while: -//ntpd: p adjtimex freq:-14545653 offset:-5396 constant:10 status:0x41 -//ntpd: c adjtimex freq:-14547835 offset:-8307 constant:10 status:0x1 -//ntpd: p adjtimex freq:-14547835 offset:-6398 constant:10 status:0x41 -//ntpd: c adjtimex freq:-14550486 offset:-10158 constant:10 status:0x1 -//ntpd: p adjtimex freq:-14550486 offset:-6132 constant:10 status:0x41 -//ntpd: c adjtimex freq:-14636129 offset:-10158 constant:10 status:0x4001 -//ntpd: p adjtimex freq:-14636129 offset:-10002 constant:10 status:0x4041 -//ntpd: c adjtimex freq:-14636245 offset:-7497 constant:10 status:0x1 -//ntpd: p adjtimex freq:-14636245 offset:-4573 constant:10 status:0x41 -//ntpd: c adjtimex freq:-14642034 offset:-11715 constant:10 status:0x1 -//ntpd: p adjtimex freq:-14642034 offset:-4098 constant:10 status:0x41 -//ntpd: c adjtimex freq:-14699112 offset:-11746 constant:10 status:0x4001 -//ntpd: p adjtimex freq:-14699112 offset:-4239 constant:10 status:0x4041 -//ntpd: c adjtimex freq:-14762330 offset:-12786 constant:10 status:0x4001 -//ntpd: p adjtimex freq:-14762330 offset:-4434 constant:10 status:0x4041 -//ntpd: b adjtimex freq:0 offset:-9669 constant:8 status:0x1 -//ntpd: adjtimex:0 freq:-14809095 offset:-9669 constant:10 status:0x4001 -//ntpd: c adjtimex freq:-14809095 offset:-9669 constant:10 status:0x4001 + /* NB: here kernel returns constant == G.poll_exp, not == G.poll_exp - 4. + * Not sure why. Perhaps it is normal. + */ + 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 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" */ } @@ -1271,98 +1771,130 @@ update_local_clock(peer_t *p, double t) * (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); - VERB3 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) /* exp is always -1 or 0 */ +static void +adjust_poll(int count) { - /* Want to send next packet at (1 << G.poll_exp) + small random value */ - unsigned interval, r; - exponent += G.poll_exp; /* G.poll_exp is always > 0 */ - /* never true: if (exp < 0) exp = 0; */ - interval = 1 << exponent; - r = random(); - interval += ((r & (interval-1)) >> 4) + ((r >> 8) & 1); /* + 1/16 of interval, max */ - VERB3 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 void +static NOINLINE void recv_and_process_peer_pkt(peer_t *p) { int rc; ssize_t size; msg_t msg; double T1, T2, T3, T4; + double offset; + double prev_delay, delay; unsigned interval; datapoint_t *datapoint; peer_t *q; + offset = 0; + /* We can recvfrom here and check from.IP, but some multihomed * 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? - set_next(p, retry_interval()); - goto close_sock; - } - 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) { bb_error_msg("malformed packet received from %s", p->p_dotted); - goto bail; + return; } if (msg.m_orgtime.int_partl != p->p_xmt_msg.m_xmttime.int_partl || msg.m_orgtime.fractionl != p->p_xmt_msg.m_xmttime.fractionl ) { - goto bail; + /* Somebody else's packet */ + return; } + /* We do not expect any more packets from this peer for now. + * Closing the socket informs kernel about it. + * We open a new socket when we send a new query. + */ + close(p->p_fd); + p->p_fd = -1; + if ((msg.m_status & LI_ALARM) == LI_ALARM || 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 - interval = poll_interval(0); - bb_error_msg("reply from %s: not synced, next query in %us", p->p_dotted, interval); - goto close_sock; + 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; } -// /* -// * Verify the server is synchronized with valid stratum and -// * reference time not later than the transmit time. -// */ -// if (p->lastpkt_leap == NOSYNC || p->lastpkt_stratum >= MAXSTRAT) -// return; /* unsynchronized */ -// // /* Verify valid root distance */ // if (msg.m_rootdelay / 2 + msg.m_rootdisp >= MAXDISP || p->lastpkt_reftime > msg.m_xmt) // return; /* invalid header values */ - p->lastpkt_leap = msg.m_status; - 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): * @@ -1380,45 +1912,100 @@ recv_and_process_peer_pkt(peer_t *p) T1 = p->p_xmttime; T2 = lfp_to_d(msg.m_rectime); T3 = lfp_to_d(msg.m_xmttime); - T4 = gettime1900d(); - - p->lastpkt_recv_time = T4; + T4 = G.cur_time; - VERB5 bb_error_msg("%s->lastpkt_recv_time=%f", p->p_dotted, p->lastpkt_recv_time); - p->datapoint_idx = p->p_reachable_bits ? (p->datapoint_idx + 1) % NUM_DATAPOINTS : 0; - datapoint = &p->filter_datapoint[p->datapoint_idx]; - datapoint->d_recv_time = T4; - datapoint->d_offset = ((T2 - T1) + (T3 - T4)) / 2; /* 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. */ - p->lastpkt_delay = (T4 - T1) - (T3 - T2); + 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. + */ + 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; + datapoint->d_offset = offset = ((T2 - T1) + (T3 - T4)) / 2; datapoint->d_dispersion = LOG2D(msg.m_precision_exp) + G_precision_sec; - if (!p->p_reachable_bits) { + if (!p->reachable_bits) { /* 1st datapoint ever - replicate offset in every element */ int i; - for (i = 1; i < NUM_DATAPOINTS; i++) { - p->filter_datapoint[i].d_offset = datapoint->d_offset; + for (i = 0; i < NUM_DATAPOINTS; i++) { + p->filter_datapoint[i].d_offset = offset; } } - p->p_reachable_bits |= 1; - VERB1 { - bb_error_msg("reply from %s: reach 0x%02x offset %f delay %f", + p->reachable_bits |= 1; + if ((MAX_VERBOSE && G.verbose) || (option_mask32 & OPT_w)) { + bb_error_msg("reply from %s: offset:%+f delay:%f status:0x%02x strat:%d refid:0x%08x rootdelay:%f reach:0x%02x", p->p_dotted, - p->p_reachable_bits, - datapoint->d_offset, p->lastpkt_delay); + offset, + p->lastpkt_delay, + p->lastpkt_status, + p->lastpkt_stratum, + p->lastpkt_refid, + p->lastpkt_rootdelay, + p->reachable_bits + /* not shown: m_ppoll, m_precision_exp, m_rootdisp, + * m_reftime, m_orgtime, m_rectime, m_xmttime + */ + ); } /* Muck with statictics and update the clock */ - filter_datapoints(p, T4); - q = select_and_cluster(T4); - rc = -1; - if (q) - rc = update_local_clock(q, T4); + filter_datapoints(p); + q = select_and_cluster(); + rc = 0; + if (q) { + 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); + 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; + } if (rc != 0) { /* Adjust the poll interval by comparing the current offset @@ -1427,74 +2014,56 @@ recv_and_process_peer_pkt(peer_t *p) * is increased, otherwise it is decreased. A bit of hysteresis * helps calm the dance. Works best using burst mode. */ - VERB4 if (rc > 0) { - bb_error_msg("offset:%f POLLADJ_GATE*discipline_jitter:%f poll:%s", - q->filter_offset, POLLADJ_GATE * G.discipline_jitter, - fabs(q->filter_offset) < POLLADJ_GATE * G.discipline_jitter - ? "grows" : "falls" - ); - } - if (rc > 0 && fabs(q->filter_offset) < POLLADJ_GATE * G.discipline_jitter) { + 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++; - VERB3 bb_error_msg("polladj: discipline_jitter:%f ++poll_exp=%d", - G.discipline_jitter, G.poll_exp); - } - } else { - VERB3 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.polladj_count = 0; - if (G.poll_exp > MINPOLL) { - G.poll_exp--; - VERB3 bb_error_msg("polladj: discipline_jitter:%f --poll_exp=%d", - G.discipline_jitter, G.poll_exp); - } - } else { - VERB3 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 */ - interval = poll_interval(0); - set_next(p, interval); + pick_normal_interval: + 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, + * or _our_ clock is wrong now and _all_ peers will show similar + * largish offsets too. + * I observed this with laptop suspend stopping clock. + * In any case, it makes sense to make next request soonish: + * cases 1 and 2: get a better datapoint, + * case 3: allows to resync faster. + */ + interval = BIGOFF_INTERVAL; + } - close_sock: - /* We do not expect any more packets from this peer for now. - * Closing the socket informs kernel about it. - * We open a new socket when we send a new query. - */ - close(p->p_fd); - p->p_fd = -1; - bail: - return; + set_next(p, interval); } #if ENABLE_FEATURE_NTPD_SERVER -static void +static NOINLINE void recv_and_process_client_pkt(void /*int fd*/) { ssize_t size; - uint8_t version; - double rectime; + //uint8_t version; len_and_sockaddr *to; struct sockaddr *from; msg_t msg; uint8_t query_status; l_fixedpt_t query_xmttime; - to = get_sock_lsa(G.listen_fd); + to = get_sock_lsa(G_listen_fd); from = xzalloc(to->len); - size = recv_from_to(G.listen_fd, &msg, sizeof(msg), MSG_DONTWAIT, from, &to->u.sa, to->len); + size = recv_from_to(G_listen_fd, &msg, sizeof(msg), MSG_DONTWAIT, from, &to->u.sa, to->len); if (size != NTP_MSGSIZE_NOAUTH && size != NTP_MSGSIZE) { char *addr; if (size < 0) { @@ -1508,31 +2077,43 @@ recv_and_process_client_pkt(void /*int fd*/) 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; /* Build a reply packet */ memset(&msg, 0, sizeof(msg)); - msg.m_status = G.stratum < MAXSTRAT ? G.leap : LI_ALARM; + msg.m_status = G.stratum < MAXSTRAT ? (G.ntp_status & LI_MASK) : LI_ALARM; msg.m_status |= (query_status & VERSION_MASK); msg.m_status |= ((query_status & MODE_MASK) == MODE_CLIENT) ? - MODE_SERVER : MODE_SYM_PAS; + MODE_SERVER : MODE_SYM_PAS; msg.m_stratum = G.stratum; msg.m_ppoll = G.poll_exp; msg.m_precision_exp = G_precision_exp; - rectime = gettime1900d(); - msg.m_xmttime = msg.m_rectime = d_to_lfp(rectime); + /* 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); //simple code does not do this, fix simple code! msg.m_rootdisp = d_to_sfp(G.rootdisp); - version = (query_status & VERSION_MASK); /* ... >> VERSION_SHIFT - done below instead */ + //version = (query_status & VERSION_MASK); /* ... >> VERSION_SHIFT - done below instead */ msg.m_refid = G.refid; // (version > (3 << VERSION_SHIFT)) ? G.refid : G.refid3; /* We reply from the local address packet was sent to, * this makes to/from look swapped here: */ - do_sendto(G.listen_fd, + do_sendto(G_listen_fd, /*from:*/ &to->u.sa, /*to:*/ from, /*addrlen:*/ to->len, &msg, size); @@ -1635,133 +2216,189 @@ static NOINLINE void ntp_init(char **argv) 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 */ -#if 0 - /* With constant b = 100, G.precision_exp is also constant -6. - * Uncomment this to verify. - */ - { - int prec = 0; - int b; -# if 0 - struct timespec tp; - /* We can use sys_clock_getres but assuming 10ms tick should be fine */ - clock_getres(CLOCK_REALTIME, &tp); - tp.tv_sec = 0; - tp.tv_nsec = 10000000; - b = 1000000000 / tp.tv_nsec; /* convert to Hz */ -# else - b = 100; /* b = 1000000000/10000000 = 100 */ -# endif - while (b > 1) - prec--, b >>= 1; - /*G.precision_exp = prec;*/ - /*G.precision_sec = (1.0 / (1 << (- prec)));*/ - bb_error_msg("G.precision_exp:%d sec:%f", prec, G_precision_sec); /* -6 */ - } -#endif + G.discipline_jitter = G_precision_sec; G.stratum = MAXSTRAT; - G.poll_exp = 1; /* should use MINPOLL, but 1 speeds up initial sync */ - G.reftime = G.last_update_recv_time = gettime1900d(); + if (BURSTPOLL != 0) + G.poll_exp = BURSTPOLL; /* speeds up initial sync */ + G.last_script_run = G.reftime = G.last_update_recv_time = gettime1900d(); /* sets G.cur_time too */ /* Parse options */ peers = NULL; - opt_complementary = "dd:p::"; /* d: counter, p: list */ + opt_complementary = "dd:wn" /* -d: counter; -p: list; -w implies -n */ + IF_FEATURE_NTPD_SERVER(":Il"); /* -I implies -l */ opts = getopt32(argv, "nqNx" /* compat */ - "p:"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.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; - while (peers) - add_peers(llist_pop(&peers)); - if (!(opts & OPT_n)) { - bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO, argv); - logmode = LOGMODE_NONE; - } + #if ENABLE_FEATURE_NTPD_SERVER - G.listen_fd = -1; + G_listen_fd = -1; if (opts & OPT_l) { - G.listen_fd = create_and_bind_dgram_or_die(NULL, 123); - socket_want_pktinfo(G.listen_fd); - setsockopt(G.listen_fd, IPPROTO_IP, IP_TOS, &const_IPTOS_LOWDELAY, sizeof(const_IPTOS_LOWDELAY)); + 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_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); - bb_signals((1 << SIGTERM) | (1 << SIGINT), record_signo); - bb_signals((1 << SIGPIPE) | (1 << SIGHUP), SIG_IGN); + 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. + * + * 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) { + option_mask32 |= OPT_qq; + alarm(10); + } + + 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; int ntpd_main(int argc UNUSED_PARAM, char **argv) { - struct globals g; +#undef G + struct globals G; struct pollfd *pfd; peer_t **idx2peer; + unsigned cnt; - memset(&g, 0, sizeof(g)); - SET_PTR_TO_GLOBALS(&g); + memset(&G, 0, sizeof(G)); + SET_PTR_TO_GLOBALS(&G); ntp_init(argv); - { - /* if ENABLE_FEATURE_NTPD_SERVER, + 1 for listen_fd: */ - unsigned cnt = g.peer_cnt + ENABLE_FEATURE_NTPD_SERVER; - idx2peer = xzalloc(sizeof(idx2peer[0]) * cnt); - pfd = xzalloc(sizeof(pfd[0]) * cnt); - } + /* If ENABLE_FEATURE_NTPD_SERVER, + 1 for listen_fd: */ + cnt = G.peer_cnt + ENABLE_FEATURE_NTPD_SERVER; + idx2peer = xzalloc(sizeof(idx2peer[0]) * cnt); + pfd = xzalloc(sizeof(pfd[0]) * cnt); + + /* 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_SAMPLES packets, + * since last reply does not come back instantaneously. + */ + cnt = G.peer_cnt * (INITIAL_SAMPLES + 1); + + write_pidfile(CONFIG_PID_FILE_PATH "/ntpd.pid"); while (!bb_got_signal) { llist_t *item; unsigned i, j; - unsigned sent_cnt, trial_cnt; int nfds, timeout; - time_t cur_time, nextaction; + double nextaction; /* Nothing between here and poll() blocks for any significant time */ - cur_time = time(NULL); - nextaction = cur_time + 3600; + nextaction = G.cur_time + 3600; i = 0; #if ENABLE_FEATURE_NTPD_SERVER - if (g.listen_fd != -1) { - pfd[0].fd = g.listen_fd; + if (G_listen_fd != -1) { + pfd[0].fd = G_listen_fd; pfd[0].events = POLLIN; i++; } #endif /* Pass over peer list, send requests, time out on receives */ - sent_cnt = trial_cnt = 0; - for (item = g.ntp_peers; item != NULL; item = item->link) { + for (item = G.ntp_peers; item != NULL; item = item->link) { peer_t *p = (peer_t *) item->data; - /* Overflow-safe "if (p->next_action_time <= cur_time) ..." */ - if ((int)(cur_time - p->next_action_time) >= 0) { + if (p->next_action_time <= G.cur_time) { if (p->p_fd == -1) { /* Time to send new req */ - trial_cnt++; - if (send_query_to_peer(p) == 0) - sent_cnt++; + if (--cnt == 0) { + 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(-1); /* try a bit faster */ + /* 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->p_reachable_bits, timeout); + 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); } } @@ -1778,39 +2415,85 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv) } } -// if ((trial_cnt > 0 && sent_cnt == 0) || g.peer_cnt == 0) { -// G.time_was_stepped = 1; -// } - - timeout = nextaction - cur_time; - if (timeout < 1) - timeout = 1; + timeout = nextaction - G.cur_time; + if (timeout < 0) + timeout = 0; + timeout++; /* (nextaction - G.cur_time) rounds down, compensating */ /* Here we may block */ - VERB2 bb_error_msg("poll %us, sockets:%u", timeout, i); + VERB2 { + if (i > (ENABLE_FEATURE_NTPD_SERVER && G_listen_fd != -1)) { + /* We wait for at least one reply. + * Poll for it, without wasting time for message. + * Since replies often come under 1 second, this also + * reduces clutter in logs. + */ + nfds = poll(pfd, i, 1000); + if (nfds != 0) + goto did_poll; + if (--timeout <= 0) + goto did_poll; + } + bb_error_msg("poll:%us sockets:%u interval:%us", timeout, i, 1 << G.poll_exp); + } nfds = poll(pfd, i, timeout * 1000); - if (nfds <= 0) - continue; + did_poll: + gettime1900d(); /* sets G.cur_time */ + if (nfds <= 0) { + if (!bb_got_signal /* poll wasn't interrupted by a signal */ + && 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 */ + } + goto check_unsync; + } /* Process any received packets */ j = 0; #if ENABLE_FEATURE_NTPD_SERVER - if (g.listen_fd != -1) { + if (G.listen_fd != -1) { if (pfd[0].revents /* & (POLLIN|POLLERR)*/) { nfds--; - recv_and_process_client_pkt(/*g.listen_fd*/); + recv_and_process_client_pkt(/*G.listen_fd*/); + gettime1900d(); /* sets G.cur_time */ } j = 1; } #endif for (; nfds != 0 && j < i; j++) { if (pfd[j].revents /* & (POLLIN|POLLERR)*/) { + /* + * At init, alarm was set to 10 sec. + * Now we did get a reply. + * Increase timeout to 50 seconds to finish syncing. + */ + if (option_mask32 & OPT_qq) { + option_mask32 &= ~OPT_qq; + alarm(50); + } nfds--; recv_and_process_peer_pkt(idx2peer[j]); + gettime1900d(); /* sets G.cur_time */ } } + + check_unsync: + if (G.ntp_peers && G.stratum != MAXSTRAT) { + for (item = G.ntp_peers; item != NULL; item = item->link) { + peer_t *p = (peer_t *) item->data; + if (p->reachable_bits) + goto have_reachable_peer; + } + /* No peer responded for last 8 packets, panic */ + clamp_pollexp_and_set_MAXSTRAT(); + run_script("unsync", 0.0); + have_reachable_peer: ; + } } /* while (!bb_got_signal) */ + remove_pidfile(CONFIG_PID_FILE_PATH "/ntpd.pid"); kill_myself_with_sig(bb_got_signal); } @@ -1827,7 +2510,6 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv) static double direct_freq(double fp_offset) { - #ifdef KERNEL_PLL /* * If the kernel is enabled, we need the residual offset to @@ -1850,7 +2532,7 @@ direct_freq(double fp_offset) } static void -set_freq(double freq) /* frequency update */ +set_freq(double freq) /* frequency update */ { char tbuf[80]; @@ -1942,14 +2624,13 @@ set_freq(double freq) /* frequency update */ if (pps_enable) { if (!(pll_status & STA_PPSTIME)) report_event(EVNT_KERN, - NULL, "PPS enabled"); + NULL, "PPS enabled"); ntv.status |= STA_PPSTIME | STA_PPSFREQ; } else { if (pll_status & STA_PPSTIME) report_event(EVNT_KERN, - NULL, "PPS disabled"); - ntv.status &= ~(STA_PPSTIME | - STA_PPSFREQ); + NULL, "PPS disabled"); + ntv.status &= ~(STA_PPSTIME | STA_PPSFREQ); } if (sys_leap == LEAP_ADDSECOND) ntv.status |= STA_INS; @@ -1965,7 +2646,7 @@ set_freq(double freq) /* frequency update */ if (ntp_adjtime(&ntv) == TIME_ERROR) { if (!(ntv.status & STA_PPSSIGNAL)) report_event(EVNT_KERN, NULL, - "PPS no signal"); + "PPS no signal"); } pll_status = ntv.status; #ifdef STA_NANO