X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Fntpd.c;h=5b92db6f66a822d3cfff9a2d24e8f59dd257d5f8;hb=11181335f9a97feddb30da4d09f9cd3739b8badd;hp=038f2bded87a731ddb7689007976f05939ad6fc4;hpb=6959f6bc23abb9057c3ed4330dad1bc8f4a1dd7a;p=oweals%2Fbusybox.git diff --git a/networking/ntpd.c b/networking/ntpd.c index 038f2bded..5b92db6f6 100644 --- a/networking/ntpd.c +++ b/networking/ntpd.c @@ -3,7 +3,7 @@ * * Author: Adam Tkac * - * Licensed under GPLv2, see file LICENSE in this tarball for details. + * Licensed under GPLv2, see file LICENSE in this source tree. * * Parts of OpenNTPD clock syncronization code is replaced by * code which is based on ntp-4.2.6, whuch carries the following @@ -27,9 +27,26 @@ * * *********************************************************************** */ + +//usage:#define ntpd_trivial_usage +//usage: "[-dnqNw"IF_FEATURE_NTPD_SERVER("l")"] [-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: 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)" + #include "libbb.h" #include #include /* For IPTOS_LOWDELAY definition */ +#include /* setpriority */ #include #ifndef IPTOS_LOWDELAY # define IPTOS_LOWDELAY 0x10 @@ -46,41 +63,84 @@ #define MAX_VERBOSE 2 +/* 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. + */ + #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 */ + +/* Clock discipline parameters and constants */ + +/* 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 (!)) */ +/* NB: set WATCH_THRESHOLD to ~60 when debugging to save time) */ +//UNUSED: #define PANIC_THRESHOLD 1000 /* panic threshold (sec) */ -#define FREQ_TOLERANCE 0.000015 /* % frequency tolerance (15 PPM) */ -#define BURSTPOLL 0 -#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 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 10 /* 2^10 sec ~= 17 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) +#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 (s) */ -#define MIN_SELECTED 1 /* % minimum intersection survivors */ -#define MIN_CLUSTERED 3 /* % minimum cluster survivors */ +#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) */ -/* 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 (!)) */ -/* NB: set WATCH_THRESHOLD to ~60 when debugging to save time) */ -#define PANIC_THRESHOLD 1000 /* panic threshold (s) */ - /* 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 @@ -153,22 +213,22 @@ 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): */ int p_fd; int datapoint_idx; uint32_t lastpkt_refid; uint8_t lastpkt_status; uint8_t lastpkt_stratum; 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 lastpkt_recv_time; @@ -185,6 +245,9 @@ typedef struct { } peer_t; +#define USING_KERNEL_PLL_LOOP 1 +#define USING_INITIAL_FREQ_ESTIMATION 0 + enum { OPT_n = (1 << 0), OPT_q = (1 << 1), @@ -196,6 +259,8 @@ enum { OPT_p = (1 << 5), OPT_S = (1 << 6), OPT_l = (1 << 7) * ENABLE_FEATURE_NTPD_SERVER, + /* We hijack some bits for other purposes */ + OPT_qq = (1 << 31), }; struct globals { @@ -212,15 +277,19 @@ struct globals { llist_t *ntp_peers; #if ENABLE_FEATURE_NTPD_SERVER int listen_fd; +# 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 ntp_status; @@ -229,44 +298,61 @@ struct globals { * 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: */ - smallint adjtimex_was_done; smallint initial_poll_complete; +#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 }; @@ -435,23 +521,34 @@ static void filter_datapoints(peer_t *p) { int i, idx; + double sum, wavg; + datapoint_t *fdp; + +#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, wavg, sum, w; + 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; - minoff = maxoff = p->filter_datapoint[0].d_offset; + 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 @@ -473,24 +570,24 @@ filter_datapoints(peer_t *p) VERB4 { 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]), - G.cur_time - 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]) / (2 << i); + sum += dispersion(&fdp[idx]) / (2 << i); - if (minoff == p->filter_datapoint[idx].d_offset) { + 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 { - oldest_off = p->filter_datapoint[idx].d_offset; - oldest_age = G.cur_time - p->filter_datapoint[idx].d_recv_time; + 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; @@ -523,6 +620,32 @@ filter_datapoints(peer_t *p) } 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 | * | --- | @@ -536,27 +659,32 @@ filter_datapoints(peer_t *p) */ 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); p->filter_jitter = sum > G_precision_sec ? sum : G_precision_sec; - VERB3 bb_error_msg("filter offset:%f(corr:%e) disp:%f jitter:%f", - p->filter_offset, x, + VERB3 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 offset) { int i; + bool small_ofs = fabs(offset) < 16 * STEP_THRESHOLD; + 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 = G.cur_time; @@ -564,14 +692,13 @@ reset_peer_stats(peer_t *p, double offset) 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 */ - p->next_action_time -= offset; VERB5 bb_error_msg("%s->lastpkt_recv_time=%f", p->p_dotted, p->lastpkt_recv_time); } @@ -654,6 +781,12 @@ send_query_to_peer(peer_t *p) 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 @@ -681,15 +814,21 @@ send_query_to_peer(peer_t *p) } p->reachable_bits <<= 1; - VERB1 bb_error_msg("sent query to %s", p->p_dotted); set_next(p, RESPONSE_INTERVAL); } -static void run_script(const char *action) +/* Note that there is no provision to prevent several run_scripts + * to be done in quick succession. In fact, it happens rather often + * if initial syncronization results in a step. + * You will see "step" and then "stratum" script runs, sometimes + * as close as only 0.002 seconds apart. + * Script should be ready to deal with this. + */ +static void run_script(const char *action, double offset) { char *argv[3]; - char *env1, *env2; + char *env1, *env2, *env3, *env4; if (!G.script_name) return; @@ -700,25 +839,35 @@ static void run_script(const char *action) VERB1 bb_error_msg("executing '%s %s'", G.script_name, action); - env1 = xasprintf("stratum=%u", G.stratum); + env1 = xasprintf("%s=%u", "stratum", G.stratum); putenv(env1); - env2 = xasprintf("freq_drift_ppm=%ld", G.kernel_freq_drift); + 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, poll_exp, - * last_update_offset, last_update_recv_time, discipline_jitter + * 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): */ - /*wait4pid(spawn(argv));*/ + /*spawn_and_wait(argv);*/ spawn(argv); - G.last_script_run = G.cur_time; unsetenv("stratum"); unsetenv("freq_drift_ppm"); + unsetenv("poll_interval"); + unsetenv("offset"); free(env1); free(env2); + free(env3); + free(env4); + + G.last_script_run = G.cur_time; } static NOINLINE void @@ -726,33 +875,49 @@ 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(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S", localtime(&tval)); + bb_error_msg("current time is %s.%06u", buf, (unsigned)tvc.tv_usec); + } + tval = tvn.tv_sec; + strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S", localtime(&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); + } } - /* Globals: */ - G.cur_time -= offset; - G.last_update_recv_time -= offset; } @@ -763,6 +928,7 @@ 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) @@ -796,7 +962,7 @@ fit(peer_t *p, double rd) VERB3 bb_error_msg("peer %s unfit for selection: unreachable", p->p_dotted); return 0; } -#if 0 /* we filter out such packets earlier */ +#if 0 /* we filter out such packets earlier */ if ((p->lastpkt_status & LI_ALARM) == LI_ALARM || p->lastpkt_stratum >= MAXSTRAT ) { @@ -813,11 +979,12 @@ fit(peer_t *p, double rd) // /* 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(void) { + peer_t *p; llist_t *item; int i, j; int size = 3 * G.peer_cnt; @@ -835,10 +1002,11 @@ select_and_cluster(void) num_points = 0; item = G.ntp_peers; if (G.initial_poll_complete) while (item != NULL) { - peer_t *p = (peer_t *) item->data; - double rd = root_distance(p); - 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; @@ -853,14 +1021,17 @@ select_and_cluster(void) 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; } @@ -941,14 +1112,12 @@ select_and_cluster(void) */ 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); + /* x.opt_rd == root_distance(p); */ + survivor[num_survivors].metric = MAXDIST * p->lastpkt_stratum + point[i].opt_rd; VERB4 bb_error_msg("survivor[%d] metric:%f peer:%s", num_survivors, survivor[num_survivors].metric, p->p_dotted); num_survivors++; @@ -992,8 +1161,8 @@ select_and_cluster(void) */ 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; @@ -1035,18 +1204,54 @@ select_and_cluster(void) } } + 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, - G.cur_time - 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) { + VERB4 bb_error_msg("keeping old synced peer"); + p = G.last_update_peer; + goto keep_old; + } + } + } + G.last_update_peer = p; + keep_old: + VERB3 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; } @@ -1066,19 +1271,13 @@ set_new_values(int disc_state, double offset, double recv_time) 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 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; @@ -1090,10 +1289,14 @@ update_local_clock(peer_t *p) 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 @@ -1113,6 +1316,7 @@ update_local_clock(peer_t *p) #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) { @@ -1120,10 +1324,11 @@ update_local_clock(peer_t *p) WATCH_THRESHOLD - since_last_update); return 0; /* "leave poll interval as is" */ } -#if !USING_KERNEL_PLL_LOOP +# if !USING_KERNEL_PLL_LOOP freq_drift = (offset - G.last_update_offset) / since_last_update; -#endif +# endif } +#endif /* There are two main regimes: when the * offset exceeds the step threshold and when it does not. @@ -1132,7 +1337,7 @@ update_local_clock(peer_t *p) 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("offset:%+f - spike detected", offset); G.discipline_state = STATE_SPIK; return -1; /* "decrease poll interval" */ @@ -1169,7 +1374,7 @@ update_local_clock(peer_t *p) * is always suppressed, even at the longer poll * intervals. */ - VERB3 bb_error_msg("stepping time by %f; poll_exp=MINPOLL", offset); + VERB3 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. */ @@ -1180,18 +1385,21 @@ update_local_clock(peer_t *p) G.poll_exp = MINPOLL; G.stratum = MAXSTRAT; - run_script("step"); + run_script("step", 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 && G.initial_poll_complete) { - VERB3 bb_error_msg("small offset:%f, disabling burst mode", offset); + VERB3 bb_error_msg("small offset:%+f, disabling burst mode", offset); G.polladj_count = 0; G.poll_exp = MINPOLL; } @@ -1200,9 +1408,8 @@ update_local_clock(peer_t *p) * 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); switch (G.discipline_state) { case STATE_NSET: @@ -1212,11 +1419,15 @@ update_local_clock(peer_t *p) */ 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); +#else + set_new_values(STATE_SYNC, offset, recv_time); +#endif VERB3 bb_error_msg("transitioning to FREQ, datapoint ignored"); return 0; /* "leave poll interval as is" */ @@ -1231,6 +1442,7 @@ update_local_clock(peer_t *p) 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. @@ -1238,6 +1450,7 @@ update_local_clock(peer_t *p) */ set_new_values(STATE_SYNC, offset, recv_time); break; +#endif default: #if !USING_KERNEL_PLL_LOOP @@ -1269,22 +1482,26 @@ update_local_clock(peer_t *p) } if (G.stratum != p->lastpkt_stratum + 1) { G.stratum = p->lastpkt_stratum + 1; - run_script("stratum"); + run_script("stratum", offset); } } + 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; G.rootdelay = p->lastpkt_rootdelay + p->lastpkt_delay; - dtemp = p->filter_jitter; // SQRT(SQUARE(p->filter_jitter) + SQUARE(s.jitter)); + 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); /* 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 @@ -1310,21 +1527,10 @@ update_local_clock(peer_t *p) 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: @@ -1334,42 +1540,42 @@ update_local_clock(peer_t *p) 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.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.esterror = (u_int32)(clock_jitter * 1e6); - //tmx.maxerror = (u_int32)((sys_rootdelay / 2 + sys_rootdisp) * 1e6); + /* 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 (tmx.constant > 0 && G.offset_to_jitter_ratio >= TIMECONST_HACK_GATE) + tmx.constant--; + + //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"); /* NB: here kernel returns constant == G.poll_exp, not == G.poll_exp - 4. * Not sure why. Perhaps it is normal. */ - 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 - VERB3 { - /* 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 - 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 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); return 1; /* "ok to increase poll interval" */ } @@ -1428,22 +1634,30 @@ recv_and_process_peer_pkt(peer_t *p) ) { //TODO: always do this? interval = retry_interval(); - goto set_next_and_close_sock; + goto set_next_and_ret; } xfunc_die(); } 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 @@ -1452,8 +1666,8 @@ recv_and_process_peer_pkt(peer_t *p) // "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 set_next_and_close_sock; + bb_error_msg("reply from %s: peer is unsynced, next query in %us", p->p_dotted, interval); + goto set_next_and_ret; } // /* Verify valid root distance */ @@ -1505,22 +1719,22 @@ recv_and_process_peer_pkt(peer_t *p) if (!p->reachable_bits) { /* 1st datapoint ever - replicate offset in every element */ int i; - for (i = 1; i < NUM_DATAPOINTS; i++) { + for (i = 0; i < NUM_DATAPOINTS; i++) { p->filter_datapoint[i].d_offset = datapoint->d_offset; } } p->reachable_bits |= 1; if ((MAX_VERBOSE && G.verbose) || (option_mask32 & OPT_w)) { - bb_error_msg("reply from %s: reach 0x%02x offset %f delay %f status 0x%02x strat %d refid 0x%08x rootdelay %f", + 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->reachable_bits, datapoint->d_offset, p->lastpkt_delay, p->lastpkt_status, p->lastpkt_stratum, p->lastpkt_refid, - p->lastpkt_rootdelay + p->lastpkt_rootdelay, + p->reachable_bits /* not shown: m_ppoll, m_precision_exp, m_rootdisp, * m_reftime, m_orgtime, m_rectime, m_xmttime */ @@ -1533,9 +1747,18 @@ recv_and_process_peer_pkt(peer_t *p) rc = -1; if (q) { rc = 0; - if (!(option_mask32 & OPT_w)) + if (!(option_mask32 & OPT_w)) { rc = update_local_clock(q); + /* If drift is dangerously large, immediately + * drop poll interval one step down. + */ + if (fabs(q->filter_offset) >= POLLDOWN_OFFSET) { + VERB3 bb_error_msg("offset:%+f > POLLDOWN_OFFSET", q->filter_offset); + goto poll_down; + } + } } + /* else: no peer selected, rc = -1: we want to poll more often */ if (rc != 0) { /* Adjust the poll interval by comparing the current offset @@ -1544,14 +1767,7 @@ 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; @@ -1567,7 +1783,8 @@ recv_and_process_peer_pkt(peer_t *p) } } else { G.polladj_count -= G.poll_exp * 2; - if (G.polladj_count < -POLLADJ_LIMIT) { + if (G.polladj_count < -POLLADJ_LIMIT || G.poll_exp >= BIGPOLL) { + poll_down: G.polladj_count = 0; if (G.poll_exp > MINPOLL) { llist_t *item; @@ -1596,16 +1813,8 @@ recv_and_process_peer_pkt(peer_t *p) /* Decide when to send new query for this peer */ interval = poll_interval(0); - set_next_and_close_sock: + set_next_and_ret: set_next(p, interval); - /* 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; } #if ENABLE_FEATURE_NTPD_SERVER @@ -1613,17 +1822,17 @@ static NOINLINE void recv_and_process_client_pkt(void /*int fd*/) { ssize_t size; - uint8_t version; + //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) { @@ -1652,17 +1861,21 @@ recv_and_process_client_pkt(void /*int fd*/) /* 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); @@ -1789,27 +2002,54 @@ static NOINLINE void ntp_init(char **argv) bb_show_usage(); // if (opts & OPT_x) /* disable stepping, only slew is allowed */ // G.time_was_stepped = 1; - while (peers) - add_peers(llist_pop(&peers)); + if (peers) { + while (peers) + add_peers(llist_pop(&peers)); + } else { + /* -l but no peers: "stratum 1 server" mode */ + G.stratum = 1; + } if (!(opts & OPT_n)) { bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO, argv); logmode = LOGMODE_NONE; } #if 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); + socket_want_pktinfo(G_listen_fd); + setsockopt(G_listen_fd, IPPROTO_IP, IP_TOS, &const_IPTOS_LOWDELAY, sizeof(const_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); - /* Removed SIGHUP here: */ - bb_signals((1 << SIGPIPE) | (1 << SIGCHLD), SIG_IGN); + /* 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; @@ -1831,13 +2071,14 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv) idx2peer = xzalloc(sizeof(idx2peer[0]) * cnt); pfd = xzalloc(sizeof(pfd[0]) * cnt); - /* Countdown: we never sync before we sent 5 packets to each peer + /* 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 5-1=4 packets, since last reply - * does not come back instantaneously. + * NB2: sync usually happens using INITIAL_SAMPLES packets, + * since last reply does not come back instantaneously. */ - cnt = G.peer_cnt * 5; + cnt = G.peer_cnt * (INITIAL_SAMPLES + 1); while (!bb_got_signal) { llist_t *item; @@ -1851,8 +2092,8 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv) 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++; } @@ -1897,15 +2138,28 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv) 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); + did_poll: gettime1900d(); /* sets G.cur_time */ if (nfds <= 0) { - if (G.adjtimex_was_done - && G.cur_time - G.last_script_run > 11*60 - ) { + if (G.script_name && G.cur_time - G.last_script_run > 11*60) { /* Useful for updating battery-backed RTC and such */ - run_script("periodic"); + run_script("periodic", G.last_update_offset); gettime1900d(); /* sets G.cur_time */ } continue; @@ -1925,6 +2179,15 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv) #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 */ @@ -1948,7 +2211,6 @@ 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 @@ -1971,7 +2233,7 @@ direct_freq(double fp_offset) } static void -set_freq(double freq) /* frequency update */ +set_freq(double freq) /* frequency update */ { char tbuf[80];