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Diffstat (limited to '')
| -rw-r--r-- | refclock.c | 738 |
1 files changed, 738 insertions, 0 deletions
diff --git a/refclock.c b/refclock.c new file mode 100644 index 0000000..8f234f6 --- /dev/null +++ b/refclock.c @@ -0,0 +1,738 @@ +/* + chronyd/chronyc - Programs for keeping computer clocks accurate. + + ********************************************************************** + * Copyright (C) Miroslav Lichvar 2009-2011, 2013-2014, 2016-2018 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + ********************************************************************** + + ======================================================================= + + Routines implementing reference clocks. + + */ + +#include "config.h" + +#include "array.h" +#include "refclock.h" +#include "reference.h" +#include "conf.h" +#include "local.h" +#include "memory.h" +#include "util.h" +#include "sources.h" +#include "logging.h" +#include "regress.h" +#include "samplefilt.h" +#include "sched.h" + +/* list of refclock drivers */ +extern RefclockDriver RCL_SHM_driver; +extern RefclockDriver RCL_SOCK_driver; +extern RefclockDriver RCL_PPS_driver; +extern RefclockDriver RCL_PHC_driver; + +struct FilterSample { + double offset; + double dispersion; + struct timespec sample_time; +}; + +struct MedianFilter { + int length; + int index; + int used; + int last; + int avg_var_n; + double avg_var; + double max_var; + struct FilterSample *samples; + int *selected; + double *x_data; + double *y_data; + double *w_data; +}; + +struct RCL_Instance_Record { + RefclockDriver *driver; + void *data; + char *driver_parameter; + int driver_parameter_length; + int driver_poll; + int driver_polled; + int poll; + int leap_status; + int pps_forced; + int pps_rate; + int pps_active; + int max_lock_age; + int stratum; + int tai; + uint32_t ref_id; + uint32_t lock_ref; + double offset; + double delay; + double precision; + double pulse_width; + SPF_Instance filter; + SCH_TimeoutID timeout_id; + SRC_Instance source; +}; + +/* Array of pointers to RCL_Instance_Record */ +static ARR_Instance refclocks; + +static LOG_FileID logfileid; + +static int valid_sample_time(RCL_Instance instance, struct timespec *sample_time); +static int pps_stratum(RCL_Instance instance, struct timespec *ts); +static void poll_timeout(void *arg); +static void slew_samples(struct timespec *raw, struct timespec *cooked, double dfreq, + double doffset, LCL_ChangeType change_type, void *anything); +static void add_dispersion(double dispersion, void *anything); +static void log_sample(RCL_Instance instance, struct timespec *sample_time, int filtered, int pulse, double raw_offset, double cooked_offset, double dispersion); + +static RCL_Instance +get_refclock(unsigned int index) +{ + return *(RCL_Instance *)ARR_GetElement(refclocks, index); +} + +void +RCL_Initialise(void) +{ + refclocks = ARR_CreateInstance(sizeof (RCL_Instance)); + + CNF_AddRefclocks(); + + if (ARR_GetSize(refclocks) > 0) { + LCL_AddParameterChangeHandler(slew_samples, NULL); + LCL_AddDispersionNotifyHandler(add_dispersion, NULL); + } + + logfileid = CNF_GetLogRefclocks() ? LOG_FileOpen("refclocks", + " Date (UTC) Time Refid DP L P Raw offset Cooked offset Disp.") + : -1; +} + +void +RCL_Finalise(void) +{ + unsigned int i; + + for (i = 0; i < ARR_GetSize(refclocks); i++) { + RCL_Instance inst = get_refclock(i); + + if (inst->driver->fini) + inst->driver->fini(inst); + + SPF_DestroyInstance(inst->filter); + Free(inst->driver_parameter); + SRC_DestroyInstance(inst->source); + Free(inst); + } + + if (ARR_GetSize(refclocks) > 0) { + LCL_RemoveParameterChangeHandler(slew_samples, NULL); + LCL_RemoveDispersionNotifyHandler(add_dispersion, NULL); + } + + ARR_DestroyInstance(refclocks); +} + +int +RCL_AddRefclock(RefclockParameters *params) +{ + RCL_Instance inst; + + inst = MallocNew(struct RCL_Instance_Record); + *(RCL_Instance *)ARR_GetNewElement(refclocks) = inst; + + if (strcmp(params->driver_name, "SHM") == 0) { + inst->driver = &RCL_SHM_driver; + } else if (strcmp(params->driver_name, "SOCK") == 0) { + inst->driver = &RCL_SOCK_driver; + } else if (strcmp(params->driver_name, "PPS") == 0) { + inst->driver = &RCL_PPS_driver; + } else if (strcmp(params->driver_name, "PHC") == 0) { + inst->driver = &RCL_PHC_driver; + } else { + LOG_FATAL("unknown refclock driver %s", params->driver_name); + } + + if (!inst->driver->init && !inst->driver->poll) + LOG_FATAL("refclock driver %s is not compiled in", params->driver_name); + + if (params->tai && !CNF_GetLeapSecTimezone()) + LOG_FATAL("refclock tai option requires leapsectz"); + + inst->data = NULL; + inst->driver_parameter = params->driver_parameter; + inst->driver_parameter_length = 0; + inst->driver_poll = params->driver_poll; + inst->poll = params->poll; + inst->driver_polled = 0; + inst->leap_status = LEAP_Normal; + inst->pps_forced = params->pps_forced; + inst->pps_rate = params->pps_rate; + inst->pps_active = 0; + inst->max_lock_age = params->max_lock_age; + inst->stratum = params->stratum; + inst->tai = params->tai; + inst->lock_ref = params->lock_ref_id; + inst->offset = params->offset; + inst->delay = params->delay; + inst->precision = LCL_GetSysPrecisionAsQuantum(); + inst->precision = MAX(inst->precision, params->precision); + inst->pulse_width = params->pulse_width; + inst->timeout_id = -1; + inst->source = NULL; + + if (inst->driver_parameter) { + int i; + + inst->driver_parameter_length = strlen(inst->driver_parameter); + for (i = 0; i < inst->driver_parameter_length; i++) + if (inst->driver_parameter[i] == ':') + inst->driver_parameter[i] = '\0'; + } + + if (inst->pps_rate < 1) + inst->pps_rate = 1; + + if (params->ref_id) + inst->ref_id = params->ref_id; + else { + unsigned char ref[5] = { 0, 0, 0, 0, 0 }; + unsigned int index = ARR_GetSize(refclocks) - 1; + + snprintf((char *)ref, sizeof (ref), "%3.3s", params->driver_name); + ref[3] = index % 10 + '0'; + if (index >= 10) + ref[2] = (index / 10) % 10 + '0'; + + inst->ref_id = (uint32_t)ref[0] << 24 | ref[1] << 16 | ref[2] << 8 | ref[3]; + } + + if (inst->driver->poll) { + int max_samples; + + if (inst->driver_poll > inst->poll) + inst->driver_poll = inst->poll; + + max_samples = 1 << (inst->poll - inst->driver_poll); + if (max_samples < params->filter_length) { + if (max_samples < 4) { + LOG(LOGS_WARN, "Setting filter length for %s to %d", + UTI_RefidToString(inst->ref_id), max_samples); + } + params->filter_length = max_samples; + } + } + + if (inst->driver->init && !inst->driver->init(inst)) + LOG_FATAL("refclock %s initialisation failed", params->driver_name); + + /* Require the filter to have at least 4 samples to produce a filtered + sample, or be full for shorter lengths, and combine 60% of samples + closest to the median */ + inst->filter = SPF_CreateInstance(MIN(params->filter_length, 4), params->filter_length, + params->max_dispersion, 0.6); + + inst->source = SRC_CreateNewInstance(inst->ref_id, SRC_REFCLOCK, params->sel_options, NULL, + params->min_samples, params->max_samples, 0.0, 0.0); + + DEBUG_LOG("refclock %s refid=%s poll=%d dpoll=%d filter=%d", + params->driver_name, UTI_RefidToString(inst->ref_id), + inst->poll, inst->driver_poll, params->filter_length); + + Free(params->driver_name); + + return 1; +} + +void +RCL_StartRefclocks(void) +{ + unsigned int i, j, n; + + n = ARR_GetSize(refclocks); + + for (i = 0; i < n; i++) { + RCL_Instance inst = get_refclock(i); + + SRC_SetActive(inst->source); + inst->timeout_id = SCH_AddTimeoutByDelay(0.0, poll_timeout, (void *)inst); + + if (inst->lock_ref) { + /* Replace lock refid with index to refclocks */ + for (j = 0; j < n && get_refclock(j)->ref_id != inst->lock_ref; j++) + ; + inst->lock_ref = j < n ? j : -1; + } else + inst->lock_ref = -1; + } +} + +void +RCL_ReportSource(RPT_SourceReport *report, struct timespec *now) +{ + unsigned int i; + uint32_t ref_id; + + assert(report->ip_addr.family == IPADDR_INET4); + ref_id = report->ip_addr.addr.in4; + + for (i = 0; i < ARR_GetSize(refclocks); i++) { + RCL_Instance inst = get_refclock(i); + if (inst->ref_id == ref_id) { + report->poll = inst->poll; + report->mode = RPT_LOCAL_REFERENCE; + break; + } + } +} + +void +RCL_SetDriverData(RCL_Instance instance, void *data) +{ + instance->data = data; +} + +void * +RCL_GetDriverData(RCL_Instance instance) +{ + return instance->data; +} + +char * +RCL_GetDriverParameter(RCL_Instance instance) +{ + return instance->driver_parameter; +} + +char * +RCL_GetDriverOption(RCL_Instance instance, char *name) +{ + char *s, *e; + int n; + + s = instance->driver_parameter; + e = s + instance->driver_parameter_length; + n = strlen(name); + + while (1) { + s += strlen(s) + 1; + if (s >= e) + break; + if (!strncmp(name, s, n)) { + if (s[n] == '=') + return s + n + 1; + if (s[n] == '\0') + return s + n; + } + } + + return NULL; +} + +static int +convert_tai_offset(struct timespec *sample_time, double *offset) +{ + struct timespec tai_ts, utc_ts; + int tai_offset; + + /* Get approximate TAI-UTC offset for the reference time in TAI */ + UTI_AddDoubleToTimespec(sample_time, *offset, &tai_ts); + tai_offset = REF_GetTaiOffset(&tai_ts); + + /* Get TAI-UTC offset for the reference time in UTC +/- 1 second */ + UTI_AddDoubleToTimespec(&tai_ts, -tai_offset, &utc_ts); + tai_offset = REF_GetTaiOffset(&utc_ts); + + if (!tai_offset) + return 0; + + *offset -= tai_offset; + + return 1; +} + +static int +accumulate_sample(RCL_Instance instance, struct timespec *sample_time, double offset, double dispersion) +{ + NTP_Sample sample; + + sample.time = *sample_time; + sample.offset = offset; + sample.peer_delay = instance->delay; + sample.root_delay = instance->delay; + sample.peer_dispersion = dispersion; + sample.root_dispersion = dispersion; + sample.leap = instance->leap_status; + + /* Handle special case when PPS is used with the local reference */ + if (instance->pps_active && instance->lock_ref == -1) + sample.stratum = pps_stratum(instance, &sample.time); + else + sample.stratum = instance->stratum; + + return SPF_AccumulateSample(instance->filter, &sample); +} + +int +RCL_AddSample(RCL_Instance instance, struct timespec *sample_time, double offset, int leap) +{ + double correction, dispersion; + struct timespec cooked_time; + + if (instance->pps_forced) + return RCL_AddPulse(instance, sample_time, -offset); + + LCL_GetOffsetCorrection(sample_time, &correction, &dispersion); + UTI_AddDoubleToTimespec(sample_time, correction, &cooked_time); + dispersion += instance->precision; + + /* Make sure the timestamp and offset provided by the driver are sane */ + if (!UTI_IsTimeOffsetSane(sample_time, offset) || + !valid_sample_time(instance, &cooked_time)) + return 0; + + switch (leap) { + case LEAP_Normal: + case LEAP_InsertSecond: + case LEAP_DeleteSecond: + instance->leap_status = leap; + break; + default: + DEBUG_LOG("refclock sample ignored bad leap %d", leap); + return 0; + } + + if (instance->tai && !convert_tai_offset(sample_time, &offset)) { + DEBUG_LOG("refclock sample ignored unknown TAI offset"); + return 0; + } + + if (!accumulate_sample(instance, &cooked_time, + offset - correction + instance->offset, dispersion)) + return 0; + + instance->pps_active = 0; + + log_sample(instance, &cooked_time, 0, 0, offset, offset - correction + instance->offset, dispersion); + + /* for logging purposes */ + if (!instance->driver->poll) + instance->driver_polled++; + + return 1; +} + +int +RCL_AddPulse(RCL_Instance instance, struct timespec *pulse_time, double second) +{ + double correction, dispersion; + struct timespec cooked_time; + + LCL_GetOffsetCorrection(pulse_time, &correction, &dispersion); + UTI_AddDoubleToTimespec(pulse_time, correction, &cooked_time); + second += correction; + + if (!UTI_IsTimeOffsetSane(pulse_time, 0.0)) + return 0; + + return RCL_AddCookedPulse(instance, &cooked_time, second, dispersion, correction); +} + +static int +check_pulse_edge(RCL_Instance instance, double offset, double distance) +{ + double max_error; + + if (instance->pulse_width <= 0.0) + return 1; + + max_error = 1.0 / instance->pps_rate - instance->pulse_width; + max_error = MIN(instance->pulse_width, max_error); + max_error *= 0.5; + + if (fabs(offset) > max_error || distance > max_error) { + DEBUG_LOG("refclock pulse ignored offset=%.9f distance=%.9f max_error=%.9f", + offset, distance, max_error); + return 0; + } + + return 1; +} + +int +RCL_AddCookedPulse(RCL_Instance instance, struct timespec *cooked_time, + double second, double dispersion, double raw_correction) +{ + double offset; + int rate; + NTP_Leap leap; + + if (!UTI_IsTimeOffsetSane(cooked_time, second) || + !valid_sample_time(instance, cooked_time)) + return 0; + + leap = LEAP_Normal; + dispersion += instance->precision; + rate = instance->pps_rate; + + offset = -second + instance->offset; + + /* Adjust the offset to [-0.5/rate, 0.5/rate) interval */ + offset -= (long)(offset * rate) / (double)rate; + if (offset < -0.5 / rate) + offset += 1.0 / rate; + else if (offset >= 0.5 / rate) + offset -= 1.0 / rate; + + if (instance->lock_ref != -1) { + RCL_Instance lock_refclock; + NTP_Sample ref_sample; + double sample_diff, shift; + + lock_refclock = get_refclock(instance->lock_ref); + + if (!SPF_GetLastSample(lock_refclock->filter, &ref_sample)) { + DEBUG_LOG("refclock pulse ignored no ref sample"); + return 0; + } + + ref_sample.root_dispersion += SPF_GetAvgSampleDispersion(lock_refclock->filter); + + sample_diff = UTI_DiffTimespecsToDouble(cooked_time, &ref_sample.time); + if (fabs(sample_diff) >= (double)instance->max_lock_age / rate) { + DEBUG_LOG("refclock pulse ignored samplediff=%.9f", + sample_diff); + return 0; + } + + /* Align the offset to the reference sample */ + if ((ref_sample.offset - offset) >= 0.0) + shift = (long)((ref_sample.offset - offset) * rate + 0.5) / (double)rate; + else + shift = (long)((ref_sample.offset - offset) * rate - 0.5) / (double)rate; + + offset += shift; + + if (fabs(ref_sample.offset - offset) + + ref_sample.root_dispersion + dispersion >= 0.2 / rate) { + DEBUG_LOG("refclock pulse ignored offdiff=%.9f refdisp=%.9f disp=%.9f", + ref_sample.offset - offset, ref_sample.root_dispersion, dispersion); + return 0; + } + + if (!check_pulse_edge(instance, ref_sample.offset - offset, 0.0)) + return 0; + + leap = lock_refclock->leap_status; + + DEBUG_LOG("refclock pulse offset=%.9f offdiff=%.9f samplediff=%.9f", + offset, ref_sample.offset - offset, sample_diff); + } else { + struct timespec ref_time; + int is_synchronised, stratum; + double root_delay, root_dispersion, distance; + uint32_t ref_id; + + /* Ignore the pulse if we are not well synchronized and the local + reference is not active */ + + REF_GetReferenceParams(cooked_time, &is_synchronised, &leap, &stratum, + &ref_id, &ref_time, &root_delay, &root_dispersion); + distance = fabs(root_delay) / 2 + root_dispersion; + + if (leap == LEAP_Unsynchronised || distance >= 0.5 / rate) { + DEBUG_LOG("refclock pulse ignored offset=%.9f sync=%d dist=%.9f", + offset, leap != LEAP_Unsynchronised, distance); + /* Drop also all stored samples */ + SPF_DropSamples(instance->filter); + return 0; + } + + if (!check_pulse_edge(instance, offset, distance)) + return 0; + } + + if (!accumulate_sample(instance, cooked_time, offset, dispersion)) + return 0; + + instance->leap_status = leap; + instance->pps_active = 1; + + log_sample(instance, cooked_time, 0, 1, offset + raw_correction - instance->offset, + offset, dispersion); + + /* for logging purposes */ + if (!instance->driver->poll) + instance->driver_polled++; + + return 1; +} + +double +RCL_GetPrecision(RCL_Instance instance) +{ + return instance->precision; +} + +int +RCL_GetDriverPoll(RCL_Instance instance) +{ + return instance->driver_poll; +} + +static int +valid_sample_time(RCL_Instance instance, struct timespec *sample_time) +{ + struct timespec now; + double diff; + + LCL_ReadCookedTime(&now, NULL); + diff = UTI_DiffTimespecsToDouble(&now, sample_time); + + if (diff < 0.0 || diff > UTI_Log2ToDouble(instance->poll + 1)) { + DEBUG_LOG("%s refclock sample time %s not valid age=%.6f", + UTI_RefidToString(instance->ref_id), + UTI_TimespecToString(sample_time), diff); + return 0; + } + + return 1; +} + +static int +pps_stratum(RCL_Instance instance, struct timespec *ts) +{ + struct timespec ref_time; + int is_synchronised, stratum; + unsigned int i; + double root_delay, root_dispersion; + NTP_Leap leap; + uint32_t ref_id; + RCL_Instance refclock; + + REF_GetReferenceParams(ts, &is_synchronised, &leap, &stratum, + &ref_id, &ref_time, &root_delay, &root_dispersion); + + /* Don't change our stratum if the local reference is active + or this is the current source */ + if (ref_id == instance->ref_id || + (!is_synchronised && leap != LEAP_Unsynchronised)) + return stratum - 1; + + /* Or the current source is another PPS refclock */ + for (i = 0; i < ARR_GetSize(refclocks); i++) { + refclock = get_refclock(i); + if (refclock->ref_id == ref_id && + refclock->pps_active && refclock->lock_ref == -1) + return stratum - 1; + } + + return 0; +} + +static void +poll_timeout(void *arg) +{ + NTP_Sample sample; + int poll; + + RCL_Instance inst = (RCL_Instance)arg; + + poll = inst->poll; + + if (inst->driver->poll) { + poll = inst->driver_poll; + inst->driver->poll(inst); + inst->driver_polled++; + } + + if (!(inst->driver->poll && inst->driver_polled < (1 << (inst->poll - inst->driver_poll)))) { + inst->driver_polled = 0; + + if (SPF_GetFilteredSample(inst->filter, &sample)) { + SRC_UpdateReachability(inst->source, 1); + SRC_AccumulateSample(inst->source, &sample); + SRC_SelectSource(inst->source); + + log_sample(inst, &sample.time, 1, 0, 0.0, sample.offset, sample.peer_dispersion); + } else { + SRC_UpdateReachability(inst->source, 0); + } + } + + inst->timeout_id = SCH_AddTimeoutByDelay(UTI_Log2ToDouble(poll), poll_timeout, arg); +} + +static void +slew_samples(struct timespec *raw, struct timespec *cooked, double dfreq, + double doffset, LCL_ChangeType change_type, void *anything) +{ + unsigned int i; + + for (i = 0; i < ARR_GetSize(refclocks); i++) { + if (change_type == LCL_ChangeUnknownStep) + SPF_DropSamples(get_refclock(i)->filter); + else + SPF_SlewSamples(get_refclock(i)->filter, cooked, dfreq, doffset); + } +} + +static void +add_dispersion(double dispersion, void *anything) +{ + unsigned int i; + + for (i = 0; i < ARR_GetSize(refclocks); i++) + SPF_AddDispersion(get_refclock(i)->filter, dispersion); +} + +static void +log_sample(RCL_Instance instance, struct timespec *sample_time, int filtered, int pulse, double raw_offset, double cooked_offset, double dispersion) +{ + char sync_stats[4] = {'N', '+', '-', '?'}; + + if (logfileid == -1) + return; + + if (!filtered) { + LOG_FileWrite(logfileid, "%s.%06d %-5s %3d %1c %1d %13.6e %13.6e %10.3e", + UTI_TimeToLogForm(sample_time->tv_sec), + (int)sample_time->tv_nsec / 1000, + UTI_RefidToString(instance->ref_id), + instance->driver_polled, + sync_stats[instance->leap_status], + pulse, + raw_offset, + cooked_offset, + dispersion); + } else { + LOG_FileWrite(logfileid, "%s.%06d %-5s - %1c - - %13.6e %10.3e", + UTI_TimeToLogForm(sample_time->tv_sec), + (int)sample_time->tv_nsec / 1000, + UTI_RefidToString(instance->ref_id), + sync_stats[instance->leap_status], + cooked_offset, + dispersion); + } +} |