We want to correct the offset quickly, but we also want to keep the frequency error caused by the correction itself low. Define correction rate as the area of the region bounded by the graph of offset corrected in time. Set the rate so that the time needed to correct an offset equal to the current sourcestats stddev will be equal to the update interval (assuming linear adjustment). The offset and the time needed to make the correction are inversely proportional. This is only a suggestion and it's up to the system driver how the adjustment will be executed.
1181 lines
34 KiB
C
1181 lines
34 KiB
C
/*
|
|
chronyd/chronyc - Programs for keeping computer clocks accurate.
|
|
|
|
**********************************************************************
|
|
* Copyright (C) Richard P. Curnow 1997-2003
|
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* Copyright (C) Miroslav Lichvar 2011
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*
|
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* This program is free software; you can redistribute it and/or modify
|
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* it under the terms of version 2 of the GNU General Public License as
|
|
* published by the Free Software Foundation.
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*
|
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* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
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*
|
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* You should have received a copy of the GNU General Public License along
|
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* with this program; if not, write to the Free Software Foundation, Inc.,
|
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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**********************************************************************
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|
|
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=======================================================================
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|
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The routines in this file manage the complete pool of sources that
|
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we might be synchronizing to. This includes NTP sources and others
|
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(e.g. local reference clocks, eyeball + wristwatch etc).
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|
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*/
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#include "config.h"
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|
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#include "sysincl.h"
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#include "sources.h"
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#include "sourcestats.h"
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#include "memory.h"
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#include "ntp.h" /* For NTP_Leap */
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#include "local.h"
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#include "reference.h"
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#include "util.h"
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#include "conf.h"
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#include "logging.h"
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#include "reports.h"
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#include "nameserv.h"
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#include "mkdirpp.h"
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/* ================================================== */
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/* Flag indicating that we are initialised */
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static int initialised = 0;
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/* ================================================== */
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/* Structure used to hold info for selecting between sources */
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struct SelectInfo {
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int stratum;
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int select_ok;
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double variance;
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double root_delay;
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double root_dispersion;
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double root_distance;
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double best_offset;
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double lo_limit;
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double hi_limit;
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};
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/* ================================================== */
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/* This enum contains the flag values that are used to label
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each source */
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typedef enum {
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SRC_OK, /* OK so far */
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SRC_UNREACHABLE, /* Source is not reachable */
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SRC_BAD_STATS, /* Stats driver could not supply valid
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data */
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SRC_FALSETICKER, /* Source is found to be a falseticker */
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SRC_JITTERY, /* Source scatter worse than other's dispersion */
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SRC_SELECTABLE, /* Source is acceptable candidate */
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SRC_SYNC /* Current synchronisation source */
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} SRC_Status;
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|
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/* ================================================== */
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/* Define the instance structure used to hold information about each
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source */
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struct SRC_Instance_Record {
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SST_Stats stats;
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NTP_Leap leap_status; /* Leap status */
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int index; /* Index back into the array of source */
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uint32_t ref_id; /* The reference ID of this source
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(i.e. from its IP address, NOT the
|
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reference _it_ is sync'd to) */
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IPAddr *ip_addr; /* Its IP address if NTP source */
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/* Flag indicating that we can use this source as a reference */
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int selectable;
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/* Reachability register */
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int reachability;
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/* Flag indicating the status of the source */
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SRC_Status status;
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/* Type of the source */
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SRC_Type type;
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/* Options used when selecting sources */
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SRC_SelectOption sel_option;
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/* Score against currently selected source */
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double sel_score;
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struct SelectInfo sel_info;
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};
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|
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/* ================================================== */
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/* Structure used to build the sort list for finding falsetickers */
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struct Sort_Element {
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int index;
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double offset;
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enum {LOW=-1, CENTRE=0, HIGH=1} tag;
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};
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/* ================================================== */
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/* Table of sources */
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static struct SRC_Instance_Record **sources;
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static struct Sort_Element *sort_list;
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static int *sel_sources;
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static int n_sources; /* Number of sources currently in the table */
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static int max_n_sources; /* Capacity of the table */
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#define INVALID_SOURCE (-1)
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static int selected_source_index; /* Which source index is currently
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selected (set to INVALID_SOURCE
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if no current valid reference) */
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/* Keep reachability status for last 8 samples */
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#define REACH_BITS 8
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/* Score needed to replace the currently selected source */
|
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#define SCORE_LIMIT 10.0
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static double reselect_distance;
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static double stratum_weight;
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|
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/* ================================================== */
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/* Forward prototype */
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static void
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slew_sources(struct timeval *raw, struct timeval *cooked, double dfreq,
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double doffset, int is_step_change, void *anything);
|
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static void
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add_dispersion(double dispersion, void *anything);
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static char *
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source_to_string(SRC_Instance inst);
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|
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/* ================================================== */
|
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/* Initialisation function */
|
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void SRC_Initialise(void) {
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sources = NULL;
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sort_list = NULL;
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n_sources = 0;
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max_n_sources = 0;
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selected_source_index = INVALID_SOURCE;
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reselect_distance = CNF_GetReselectDistance();
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stratum_weight = CNF_GetStratumWeight();
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initialised = 1;
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|
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LCL_AddParameterChangeHandler(slew_sources, NULL);
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LCL_AddDispersionNotifyHandler(add_dispersion, NULL);
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return;
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}
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|
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/* ================================================== */
|
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/* Finalisation function */
|
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void SRC_Finalise(void)
|
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{
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LCL_RemoveParameterChangeHandler(slew_sources, NULL);
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LCL_RemoveDispersionNotifyHandler(add_dispersion, NULL);
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initialised = 0;
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return;
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}
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/* ================================================== */
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/* Function to create a new instance. This would be called by one of
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the individual source-type instance creation routines. */
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SRC_Instance SRC_CreateNewInstance(uint32_t ref_id, SRC_Type type, SRC_SelectOption sel_option, IPAddr *addr)
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{
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SRC_Instance result;
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assert(initialised);
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result = MallocNew(struct SRC_Instance_Record);
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result->stats = SST_CreateInstance(ref_id, addr);
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if (n_sources == max_n_sources) {
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/* Reallocate memory */
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max_n_sources += 32;
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if (sources) {
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sources = ReallocArray(struct SRC_Instance_Record *, max_n_sources, sources);
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sort_list = ReallocArray(struct Sort_Element, 3*max_n_sources, sort_list);
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sel_sources = ReallocArray(int, max_n_sources, sel_sources);
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} else {
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sources = MallocArray(struct SRC_Instance_Record *, max_n_sources);
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sort_list = MallocArray(struct Sort_Element, 3*max_n_sources);
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sel_sources = MallocArray(int, max_n_sources);
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}
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}
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sources[n_sources] = result;
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result->index = n_sources;
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result->leap_status = LEAP_Normal;
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result->ref_id = ref_id;
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result->ip_addr = addr;
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result->selectable = 0;
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result->reachability = 0;
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result->status = SRC_BAD_STATS;
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result->type = type;
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result->sel_score = 1.0;
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result->sel_option = sel_option;
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n_sources++;
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return result;
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}
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/* ================================================== */
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/* Function to get rid of a source when it is being unconfigured.
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This may cause the current reference source to be reselected, if this
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was the reference source or contributed significantly to a
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falseticker decision. */
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void SRC_DestroyInstance(SRC_Instance instance)
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{
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int dead_index, i;
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assert(initialised);
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SRC_UnsetSelectable(instance);
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SST_DeleteInstance(instance->stats);
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dead_index = instance->index;
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for (i=dead_index; i<n_sources-1; i++) {
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sources[i] = sources[i+1];
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sources[i]->index = i;
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}
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--n_sources;
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Free(instance);
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if (selected_source_index > dead_index) {
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--selected_source_index;
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}
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}
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/* ================================================== */
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/* Function to get the range of frequencies, relative to the given
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source, that we believe the local clock lies within. The return
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values are in terms of the number of seconds fast (+ve) or slow
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(-ve) relative to the source that the local clock becomes after a
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given amount of local time has elapsed.
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Suppose the initial offset relative to the source is U (fast +ve,
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slow -ve) and a time interval T elapses measured in terms of the
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local clock. Then the error relative to the source at the end of
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the interval should lie in the interval [U+T*lo, U+T*hi]. */
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void SRC_GetFrequencyRange(SRC_Instance instance, double *lo, double *hi)
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{
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assert(initialised);
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SST_GetFrequencyRange(instance->stats, lo, hi);
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return;
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}
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|
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/* ================================================== */
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/* This function is called by one of the source drivers when it has
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a new sample that is to be accumulated.
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This function causes the frequency estimation to be re-run for the
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designated source, and the clock selection procedure to be re-run
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afterwards.
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Parameters are described in sources.h
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*/
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void SRC_AccumulateSample
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(SRC_Instance inst,
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struct timeval *sample_time,
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double offset,
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double peer_delay,
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double peer_dispersion,
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|
double root_delay,
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double root_dispersion,
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int stratum,
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NTP_Leap leap_status)
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|
{
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|
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assert(initialised);
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inst->leap_status = leap_status;
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#ifdef TRACEON
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LOG(LOGS_INFO, LOGF_Sources, "ip=[%s] t=%s ofs=%f del=%f disp=%f str=%d",
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source_to_string(inst), UTI_TimevalToString(sample_time), -offset, root_delay, root_dispersion, stratum);
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#endif
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/* WE HAVE TO NEGATE OFFSET IN THIS CALL, IT IS HERE THAT THE SENSE OF OFFSET
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IS FLIPPED */
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SST_AccumulateSample(inst->stats, sample_time, -offset, peer_delay, peer_dispersion, root_delay, root_dispersion, stratum);
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SST_DoNewRegression(inst->stats);
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/* And redo clock selection */
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SRC_SelectSource(inst->ref_id);
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return;
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}
|
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|
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/* ================================================== */
|
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|
|
void
|
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SRC_SetSelectable(SRC_Instance inst)
|
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{
|
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inst->selectable = 1;
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|
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#ifdef TRACEON
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LOG(LOGS_INFO, LOGF_Sources, "%s", source_to_string(inst));
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#endif
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|
|
/* Don't do selection at this point, though - that will come about
|
|
in due course when we get some useful data from the source */
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
SRC_UnsetSelectable(SRC_Instance inst)
|
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{
|
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inst->selectable = 0;
|
|
|
|
#ifdef TRACEON
|
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LOG(LOGS_INFO, LOGF_Sources, "%s%s", source_to_string(inst),
|
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(inst->index == selected_source_index) ? "(REF)":"");
|
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#endif
|
|
|
|
/* If this was the previous reference source, we have to reselect! */
|
|
|
|
if (inst->index == selected_source_index) {
|
|
SRC_SelectSource(0);
|
|
}
|
|
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
SRC_UpdateReachability(SRC_Instance inst, int reachable)
|
|
{
|
|
inst->reachability <<= 1;
|
|
inst->reachability |= !!reachable;
|
|
inst->reachability &= ~(-1 << REACH_BITS);
|
|
|
|
if (!reachable && inst->index == selected_source_index) {
|
|
/* Try to select a better source */
|
|
SRC_SelectSource(0);
|
|
}
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
SRC_ResetReachability(SRC_Instance inst)
|
|
{
|
|
/* This should be disabled until source selection is modified to keep
|
|
a peer selected even when not reachable */
|
|
#if 0
|
|
inst->reachability = 0;
|
|
SRC_UpdateReachability(inst, 0);
|
|
#endif
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static int
|
|
compare_sort_elements(const void *a, const void *b)
|
|
{
|
|
const struct Sort_Element *u = (const struct Sort_Element *) a;
|
|
const struct Sort_Element *v = (const struct Sort_Element *) b;
|
|
|
|
if (u->offset < v->offset) {
|
|
return -1;
|
|
} else if (u->offset > v->offset) {
|
|
return +1;
|
|
} else if (u->tag < v->tag) {
|
|
return -1;
|
|
} else if (u->tag > v->tag) {
|
|
return +1;
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
static char *
|
|
source_to_string(SRC_Instance inst)
|
|
{
|
|
switch (inst->type) {
|
|
case SRC_NTP:
|
|
return UTI_IPToString(inst->ip_addr);
|
|
case SRC_REFCLOCK:
|
|
return UTI_RefidToString(inst->ref_id);
|
|
default:
|
|
assert(0);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* ================================================== */
|
|
/* This function selects the current reference from amongst the pool
|
|
of sources we are holding.
|
|
|
|
Updates are only made to the local reference if a new source is selected
|
|
or match_refid is equal to the selected reference source refid */
|
|
|
|
void
|
|
SRC_SelectSource(uint32_t match_refid)
|
|
{
|
|
int i, j, index, old_selected_index;
|
|
struct timeval now, ref_time;
|
|
double src_offset, src_offset_sd, src_frequency, src_skew;
|
|
double src_root_delay, src_root_dispersion;
|
|
int n_endpoints, j1, j2;
|
|
double best_lo, best_hi;
|
|
int depth, best_depth;
|
|
int n_sel_sources;
|
|
double distance, sel_src_distance;
|
|
int stratum, min_stratum;
|
|
struct SelectInfo *si;
|
|
int n_badstats_sources;
|
|
int max_sel_reach, max_badstat_reach;
|
|
int max_score_index;
|
|
double max_score;
|
|
|
|
NTP_Leap leap_status = LEAP_Normal;
|
|
old_selected_index = selected_source_index;
|
|
|
|
if (n_sources == 0) {
|
|
/* In this case, we clearly cannot synchronise to anything */
|
|
if (selected_source_index != INVALID_SOURCE) {
|
|
LOG(LOGS_INFO, LOGF_Sources, "Can't synchronise: no sources");
|
|
selected_source_index = INVALID_SOURCE;
|
|
REF_SetUnsynchronised();
|
|
}
|
|
return;
|
|
}
|
|
|
|
LCL_ReadCookedTime(&now, NULL);
|
|
|
|
/* Step 1 - build intervals about each source */
|
|
n_endpoints = 0;
|
|
n_sel_sources = 0;
|
|
n_badstats_sources = 0;
|
|
max_sel_reach = max_badstat_reach = 0;
|
|
for (i=0; i<n_sources; i++) {
|
|
|
|
if (sources[i]->selectable && sources[i]->reachability &&
|
|
sources[i]->sel_option != SRC_SelectNoselect) {
|
|
|
|
si = &(sources[i]->sel_info);
|
|
SST_GetSelectionData(sources[i]->stats, &now,
|
|
&(si->stratum),
|
|
&(si->best_offset),
|
|
&(si->root_delay),
|
|
&(si->root_dispersion),
|
|
&(si->variance),
|
|
&(si->select_ok));
|
|
|
|
si->root_distance = si->root_dispersion + 0.5 * fabs(si->root_delay);
|
|
si->lo_limit = si->best_offset - si->root_distance;
|
|
si->hi_limit = si->best_offset + si->root_distance;
|
|
|
|
#if 0
|
|
LOG(LOGS_INFO, LOGF_Sources, "%s off=%f dist=%f lo=%f hi=%f",
|
|
source_to_string(sources[i]),
|
|
si->best_offset, si->root_distance,
|
|
si->lo_limit, si->hi_limit);
|
|
#endif
|
|
|
|
if (si->select_ok) {
|
|
++n_sel_sources;
|
|
|
|
sources[i]->status = SRC_OK; /* For now */
|
|
|
|
/* Otherwise it will be hard to pick this one later! However,
|
|
this test might be too strict, we might want to dump it */
|
|
j1 = n_endpoints;
|
|
j2 = j1 + 1;
|
|
|
|
sort_list[j1].index = i;
|
|
sort_list[j1].offset = si->lo_limit;
|
|
sort_list[j1].tag = LOW;
|
|
|
|
sort_list[j2].index = i;
|
|
sort_list[j2].offset = si->hi_limit;
|
|
sort_list[j2].tag = HIGH;
|
|
|
|
n_endpoints += 2;
|
|
|
|
if (max_sel_reach < sources[i]->reachability) {
|
|
max_sel_reach = sources[i]->reachability;
|
|
}
|
|
} else {
|
|
++n_badstats_sources;
|
|
sources[i]->status = SRC_BAD_STATS;
|
|
|
|
if (max_badstat_reach < sources[i]->reachability) {
|
|
max_badstat_reach = sources[i]->reachability;
|
|
}
|
|
}
|
|
} else {
|
|
/* If the source is not reachable, there is no way we will pick
|
|
it. */
|
|
sources[i]->status = SRC_UNREACHABLE;
|
|
}
|
|
}
|
|
|
|
#if 0
|
|
LOG(LOGS_INFO, LOGF_Sources, "badstat_sources=%d sel_sources=%d badstat_reach=%x sel_reach=%x",
|
|
n_badstats_sources, n_sel_sources, max_badstat_reach, max_sel_reach);
|
|
#endif
|
|
|
|
/* Wait for the next call if we have no source selected and there is
|
|
a source with bad stats (has less than 3 samples) with reachability
|
|
equal to shifted maximum reachability of sources with valid stats.
|
|
This delays selecting source on start with servers using the same
|
|
polling interval until they all have valid stats. */
|
|
|
|
if (n_badstats_sources && n_sel_sources &&
|
|
selected_source_index == INVALID_SOURCE &&
|
|
max_sel_reach >> 1 == max_badstat_reach) {
|
|
return;
|
|
}
|
|
|
|
#if 0
|
|
LOG(LOGS_INFO, LOGF_Sources, "n_endpoints=%d", n_endpoints);
|
|
#endif
|
|
|
|
/* Now sort the endpoint list */
|
|
if (n_endpoints > 0) {
|
|
|
|
/* Sort the list into order */
|
|
qsort((void *) sort_list, n_endpoints, sizeof(struct Sort_Element), compare_sort_elements);
|
|
|
|
/* Now search for the interval which is contained in the most
|
|
individual source intervals. Any source which overlaps this
|
|
will be a candidate.
|
|
|
|
If we get a case like
|
|
|
|
<----------------------->
|
|
<-->
|
|
<-->
|
|
<===========>
|
|
|
|
we will build the interval as shown with '=', whereas with an extra source we get
|
|
<----------------------->
|
|
<------->
|
|
<-->
|
|
<-->
|
|
<==>
|
|
|
|
The first case is just bad luck - we need extra sources to
|
|
detect the falseticker, so just make an arbitrary choice based
|
|
on stratum & stability etc.
|
|
*/
|
|
|
|
depth = best_depth = 0;
|
|
best_lo = best_hi = 0.0;
|
|
|
|
for (i=0; i<n_endpoints; i++) {
|
|
#if 0
|
|
LOG(LOGS_INFO, LOGF_Sources, "i=%d t=%f tag=%d addr=%s", i, sort_list[i].offset, sort_list[i].tag,
|
|
source_to_string(sources[sort_list[i].index]));
|
|
#endif
|
|
switch(sort_list[i].tag) {
|
|
case LOW:
|
|
depth++;
|
|
if (depth > best_depth) {
|
|
best_depth = depth;
|
|
best_lo = sort_list[i].offset;
|
|
}
|
|
break;
|
|
|
|
case CENTRE:
|
|
assert(0);
|
|
break;
|
|
|
|
case HIGH:
|
|
if (depth == best_depth) {
|
|
best_hi = sort_list[i].offset;
|
|
}
|
|
depth--;
|
|
break;
|
|
|
|
}
|
|
}
|
|
|
|
#if 0
|
|
LOG(LOGS_INFO, LOGF_Sources, "best_depth=%d best_lo=%f best_hi=%f",
|
|
best_depth, best_lo, best_hi);
|
|
#endif
|
|
|
|
if (best_depth <= n_sel_sources/2) {
|
|
/* Could not even get half the reachable sources to agree -
|
|
clearly we can't synchronise.
|
|
|
|
srcs #to agree
|
|
1 1
|
|
2 2
|
|
3 2
|
|
4 3 etc
|
|
|
|
*/
|
|
|
|
if (selected_source_index != INVALID_SOURCE) {
|
|
LOG(LOGS_INFO, LOGF_Sources, "Can't synchronise: no majority");
|
|
}
|
|
selected_source_index = INVALID_SOURCE;
|
|
|
|
/* .. and mark all sources as falsetickers (so they appear thus
|
|
on the outputs from the command client) */
|
|
|
|
for (i=0; i<n_sources; i++) {
|
|
sources[i]->status = SRC_FALSETICKER;
|
|
}
|
|
|
|
} else {
|
|
|
|
/* We have our interval, now work out which source are in it,
|
|
i.e. build list of admissible sources. */
|
|
|
|
n_sel_sources = 0;
|
|
for (i=0; i<n_sources; i++) {
|
|
if (sources[i]->status == SRC_OK) {
|
|
/* This should be the same condition to get into the endpoint
|
|
list */
|
|
/* Check if source's interval contains the best interval, or
|
|
is wholly contained within it */
|
|
if (((sources[i]->sel_info.lo_limit <= best_lo) &&
|
|
(sources[i]->sel_info.hi_limit >= best_hi)) ||
|
|
((sources[i]->sel_info.lo_limit >= best_lo) &&
|
|
(sources[i]->sel_info.hi_limit <= best_hi))) {
|
|
|
|
sel_sources[n_sel_sources++] = i;
|
|
#if 0
|
|
LOG(LOGS_INFO, LOGF_Sources, "i=%d addr=%s is valid", i, source_to_string(sources[i]));
|
|
#endif
|
|
} else {
|
|
sources[i]->status = SRC_FALSETICKER;
|
|
#if 0
|
|
LOG(LOGS_INFO, LOGF_Sources, "i=%d addr=%s is a falseticker", i, source_to_string(sources[i]));
|
|
#endif
|
|
}
|
|
}
|
|
}
|
|
|
|
#if 0
|
|
/* We now have a list of indices for the sources which pass the
|
|
false-ticker test. Now go on to reject those whose variance is
|
|
greater than the minimum distance of any other */
|
|
|
|
/* Find minimum distance */
|
|
index = sel_sources[0];
|
|
min_distance = sources[index]->sel_info.root_distance;
|
|
for (i=1; i<n_sel_sources; i++) {
|
|
index = sel_sources[i];
|
|
distance = sources[index]->sel_info.root_distance;
|
|
if (distance < min_distance) {
|
|
min_distance = distance;
|
|
}
|
|
}
|
|
|
|
#if 0
|
|
LOG(LOGS_INFO, LOGF_Sources, "min_distance=%f", min_distance);
|
|
#endif
|
|
|
|
/* Now go through and prune any NTP sources that have excessive
|
|
variance */
|
|
for (i=0; i<n_sel_sources; i++) {
|
|
index = sel_sources[i];
|
|
if (sources[index]->type == SRC_NTP &&
|
|
sqrt(sources[index]->sel_info.variance) > min_distance) {
|
|
sel_sources[i] = INVALID_SOURCE;
|
|
sources[index]->status = SRC_JITTERY;
|
|
#if 0
|
|
LOG(LOGS_INFO, LOGF_Sources, "i=%d addr=%s has too much variance", i, source_to_string(sources[i]));
|
|
#endif
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* Now crunch the list and mark all sources as selectable */
|
|
for (i=j=0; i<n_sel_sources; i++) {
|
|
index = sel_sources[i];
|
|
if (index != INVALID_SOURCE) {
|
|
sources[index]->status = SRC_SELECTABLE;
|
|
sel_sources[j++] = sel_sources[i];
|
|
index++;
|
|
}
|
|
}
|
|
n_sel_sources = j;
|
|
|
|
if (n_sel_sources > 0) {
|
|
/* Accept leap second status if more than half of selectable sources agree */
|
|
|
|
for (i=j1=j2=0; i<n_sel_sources; i++) {
|
|
index = sel_sources[i];
|
|
if (sources[index]->leap_status == LEAP_InsertSecond) {
|
|
j1++;
|
|
} else if (sources[index]->leap_status == LEAP_DeleteSecond) {
|
|
j2++;
|
|
}
|
|
}
|
|
|
|
if (j1 > n_sel_sources / 2) {
|
|
leap_status = LEAP_InsertSecond;
|
|
} else if (j2 > n_sel_sources / 2) {
|
|
leap_status = LEAP_DeleteSecond;
|
|
}
|
|
|
|
/* If there are any sources with prefer option, reduce the list again
|
|
only to the prefer sources */
|
|
for (i=j=0; i<n_sel_sources; i++) {
|
|
if (sources[sel_sources[i]]->sel_option == SRC_SelectPrefer) {
|
|
sel_sources[j++] = sel_sources[i];
|
|
}
|
|
}
|
|
if (j > 0) {
|
|
n_sel_sources = j;
|
|
}
|
|
|
|
/* Now find minimum stratum. If none are left now,
|
|
tough. RFC1305 is not so harsh on pruning sources due to
|
|
excess variance, which prevents this from happening */
|
|
|
|
index = sel_sources[0];
|
|
min_stratum = sources[index]->sel_info.stratum;
|
|
for (i=1; i<n_sel_sources; i++) {
|
|
index = sel_sources[i];
|
|
stratum = sources[index]->sel_info.stratum;
|
|
if (stratum < min_stratum) min_stratum = stratum;
|
|
}
|
|
|
|
#if 0
|
|
LOG(LOGS_INFO, LOGF_Sources, "min_stratum=%d", min_stratum);
|
|
#endif
|
|
|
|
/* Update scores and find source with maximum score */
|
|
|
|
max_score_index = INVALID_SOURCE;
|
|
max_score = 0.0;
|
|
sel_src_distance = 0.0;
|
|
|
|
if (selected_source_index != INVALID_SOURCE) {
|
|
sel_src_distance = sources[selected_source_index]->sel_info.root_distance +
|
|
(sources[selected_source_index]->sel_info.stratum - min_stratum) * stratum_weight;
|
|
}
|
|
|
|
for (i = 0; i < n_sources; i++) {
|
|
|
|
/* Reset score for non-selectable sources */
|
|
if (sources[i]->status != SRC_SELECTABLE) {
|
|
sources[i]->sel_score = 1.0;
|
|
continue;
|
|
}
|
|
|
|
distance = sources[i]->sel_info.root_distance +
|
|
(sources[i]->sel_info.stratum - min_stratum) * stratum_weight;
|
|
if (sources[i]->type == SRC_NTP)
|
|
distance += reselect_distance;
|
|
|
|
if (selected_source_index != INVALID_SOURCE) {
|
|
|
|
/* Update score, but only for source pairs where one source
|
|
has a new sample */
|
|
if (sources[i]->ref_id == match_refid ||
|
|
sources[selected_source_index]->ref_id == match_refid) {
|
|
|
|
sources[i]->sel_score *= sel_src_distance / distance;
|
|
|
|
if (sources[i]->sel_score < 1.0)
|
|
sources[i]->sel_score = 1.0;
|
|
}
|
|
|
|
} else {
|
|
|
|
/* When there is no selected source yet, assign scores so the
|
|
source with minimum distance will have maximum score. The scores
|
|
will be immediately reset. */
|
|
|
|
sources[i]->sel_score = 1.0 / distance;
|
|
}
|
|
|
|
#if 0
|
|
LOG(LOGS_INFO, LOGF_Sources, "select score=%f refid=%lx match_refid=%lx status=%d dist=%f",
|
|
sources[i]->sel_score, sources[i]->ref_id, match_refid, sources[i]->status, distance);
|
|
#endif
|
|
|
|
if (max_score < sources[i]->sel_score) {
|
|
max_score = sources[i]->sel_score;
|
|
max_score_index = i;
|
|
}
|
|
}
|
|
|
|
assert(max_score_index != INVALID_SOURCE);
|
|
|
|
/* Is the current source still a survivor
|
|
and no other source has reached the score limit? */
|
|
|
|
if ((selected_source_index == INVALID_SOURCE) ||
|
|
(sources[selected_source_index]->status != SRC_SELECTABLE) ||
|
|
(max_score_index != selected_source_index && max_score > SCORE_LIMIT)) {
|
|
|
|
/* We have to elect a new synchronisation source */
|
|
|
|
selected_source_index = max_score_index;
|
|
LOG(LOGS_INFO, LOGF_Sources, "Selected source %s",
|
|
source_to_string(sources[selected_source_index]));
|
|
|
|
#if 0
|
|
LOG(LOGS_INFO, LOGF_Sources, "new_sel_index=%d", selected_source_index);
|
|
#endif
|
|
|
|
/* New source has been selected, reset all scores */
|
|
for (i=0; i < n_sources; i++) {
|
|
sources[i]->sel_score = 1.0;
|
|
}
|
|
}
|
|
|
|
sources[selected_source_index]->status = SRC_SYNC;
|
|
|
|
/* Update local reference only when a new source was selected or a new
|
|
sample was received (i.e. match_refid is equal to selected refid) */
|
|
if (selected_source_index != old_selected_index ||
|
|
match_refid == sources[selected_source_index]->ref_id) {
|
|
|
|
/* Now just use the statistics of the selected source for
|
|
trimming the local clock */
|
|
|
|
SST_GetTrackingData(sources[selected_source_index]->stats, &ref_time,
|
|
&src_offset, &src_offset_sd,
|
|
&src_frequency, &src_skew,
|
|
&src_root_delay, &src_root_dispersion);
|
|
|
|
REF_SetReference(min_stratum, leap_status,
|
|
sources[selected_source_index]->ref_id,
|
|
sources[selected_source_index]->ip_addr,
|
|
&ref_time,
|
|
src_offset,
|
|
src_offset_sd,
|
|
src_frequency,
|
|
src_skew,
|
|
src_root_delay,
|
|
src_root_dispersion);
|
|
}
|
|
|
|
} else {
|
|
if (selected_source_index != INVALID_SOURCE) {
|
|
LOG(LOGS_INFO, LOGF_Sources, "Can't synchronise: no selectable sources");
|
|
}
|
|
selected_source_index = INVALID_SOURCE;
|
|
}
|
|
}
|
|
|
|
} else {
|
|
/* No sources provided valid endpoints */
|
|
if (selected_source_index != INVALID_SOURCE) {
|
|
LOG(LOGS_INFO, LOGF_Sources, "Can't synchronise: no reachable sources");
|
|
}
|
|
selected_source_index = INVALID_SOURCE;
|
|
}
|
|
|
|
if (selected_source_index == INVALID_SOURCE &&
|
|
selected_source_index != old_selected_index) {
|
|
REF_SetUnsynchronised();
|
|
}
|
|
}
|
|
|
|
/* ================================================== */
|
|
/* Force reselecting the best source */
|
|
|
|
void
|
|
SRC_ReselectSource(void)
|
|
{
|
|
selected_source_index = INVALID_SOURCE;
|
|
SRC_SelectSource(0);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
SRC_SetReselectDistance(double distance)
|
|
{
|
|
if (reselect_distance != distance) {
|
|
reselect_distance = distance;
|
|
LOG(LOGS_INFO, LOGF_Sources, "New reselect distance %f", distance);
|
|
}
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
double
|
|
SRC_PredictOffset(SRC_Instance inst, struct timeval *when)
|
|
{
|
|
return SST_PredictOffset(inst->stats, when);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
double
|
|
SRC_MinRoundTripDelay(SRC_Instance inst)
|
|
{
|
|
return SST_MinRoundTripDelay(inst->stats);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
SRC_IsGoodSample(SRC_Instance inst, double offset, double delay,
|
|
double max_delay_dev_ratio, double clock_error, struct timeval *when)
|
|
{
|
|
return SST_IsGoodSample(inst->stats, offset, delay, max_delay_dev_ratio,
|
|
clock_error, when);
|
|
}
|
|
|
|
/* ================================================== */
|
|
/* This routine is registered as a callback with the local clock
|
|
module, to be called whenever the local clock changes frequency or
|
|
is slewed. It runs through all the existing source statistics, and
|
|
adjusts them to make them look as though they were sampled under
|
|
the new regime. */
|
|
|
|
static void
|
|
slew_sources(struct timeval *raw,
|
|
struct timeval *cooked,
|
|
double dfreq,
|
|
double doffset,
|
|
int is_step_change,
|
|
void *anything)
|
|
{
|
|
int i;
|
|
|
|
for (i=0; i<n_sources; i++) {
|
|
SST_SlewSamples(sources[i]->stats, cooked, dfreq, doffset);
|
|
}
|
|
|
|
}
|
|
|
|
/* ================================================== */
|
|
/* This routine is called when an indeterminate offset is introduced
|
|
into the local time. */
|
|
|
|
static void
|
|
add_dispersion(double dispersion, void *anything)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < n_sources; i++) {
|
|
SST_AddDispersion(sources[i]->stats, dispersion);
|
|
}
|
|
}
|
|
|
|
/* ================================================== */
|
|
/* This is called to dump out the source measurement registers */
|
|
|
|
void
|
|
SRC_DumpSources(void)
|
|
{
|
|
FILE *out;
|
|
int direc_len, file_len;
|
|
char *filename;
|
|
unsigned int a, b, c, d;
|
|
int i;
|
|
char *direc;
|
|
|
|
direc = CNF_GetDumpDir();
|
|
direc_len = strlen(direc);
|
|
file_len = direc_len + 24;
|
|
filename = MallocArray(char, file_len); /* a bit of slack */
|
|
if (mkdir_and_parents(direc)) {
|
|
for (i=0; i<n_sources; i++) {
|
|
a = (sources[i]->ref_id) >> 24;
|
|
b = ((sources[i]->ref_id) >> 16) & 0xff;
|
|
c = ((sources[i]->ref_id) >> 8) & 0xff;
|
|
d = ((sources[i]->ref_id)) & 0xff;
|
|
|
|
snprintf(filename, file_len-1, "%s/%d.%d.%d.%d.dat", direc, a, b, c, d);
|
|
out = fopen(filename, "w");
|
|
if (!out) {
|
|
LOG(LOGS_WARN, LOGF_Sources, "Could not open dump file %s", filename);
|
|
} else {
|
|
SST_SaveToFile(sources[i]->stats, out);
|
|
fclose(out);
|
|
}
|
|
}
|
|
} else {
|
|
LOG(LOGS_ERR, LOGF_Sources, "Could not create directory %s", direc);
|
|
}
|
|
Free(filename);
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
void
|
|
SRC_ReloadSources(void)
|
|
{
|
|
FILE *in;
|
|
char *filename;
|
|
unsigned int a, b, c, d;
|
|
int i;
|
|
char *dumpdir;
|
|
int dumpdirlen, filelen;
|
|
|
|
for (i=0; i<n_sources; i++) {
|
|
a = (sources[i]->ref_id) >> 24;
|
|
b = ((sources[i]->ref_id) >> 16) & 0xff;
|
|
c = ((sources[i]->ref_id) >> 8) & 0xff;
|
|
d = ((sources[i]->ref_id)) & 0xff;
|
|
|
|
dumpdir = CNF_GetDumpDir();
|
|
dumpdirlen = strlen(dumpdir);
|
|
filelen = dumpdirlen + 24;
|
|
filename = MallocArray(char, filelen);
|
|
snprintf(filename, filelen-1, "%s/%d.%d.%d.%d.dat", dumpdir, a, b, c, d);
|
|
in = fopen(filename, "r");
|
|
if (!in) {
|
|
LOG(LOGS_WARN, LOGF_Sources, "Could not open dump file %s", filename);
|
|
} else {
|
|
if (SST_LoadFromFile(sources[i]->stats, in)) {
|
|
SST_DoNewRegression(sources[i]->stats);
|
|
} else {
|
|
LOG(LOGS_WARN, LOGF_Sources, "Problem loading from file %s", filename);
|
|
}
|
|
fclose(in);
|
|
}
|
|
Free(filename);
|
|
}
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
SRC_IsSyncPeer(SRC_Instance inst)
|
|
{
|
|
if (inst->index == selected_source_index) {
|
|
return 1;
|
|
} else {
|
|
return 0;
|
|
}
|
|
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
SRC_ReadNumberOfSources(void)
|
|
{
|
|
return n_sources;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
SRC_ReportSource(int index, RPT_SourceReport *report, struct timeval *now)
|
|
{
|
|
SRC_Instance src;
|
|
if ((index >= n_sources) || (index < 0)) {
|
|
return 0;
|
|
} else {
|
|
src = sources[index];
|
|
|
|
memset(&report->ip_addr, 0, sizeof (report->ip_addr));
|
|
if (src->ip_addr)
|
|
report->ip_addr = *src->ip_addr;
|
|
else {
|
|
/* Use refid as an address */
|
|
report->ip_addr.addr.in4 = src->ref_id;
|
|
report->ip_addr.family = IPADDR_INET4;
|
|
}
|
|
|
|
switch (src->status) {
|
|
case SRC_SYNC:
|
|
report->state = RPT_SYNC;
|
|
break;
|
|
case SRC_JITTERY:
|
|
report->state = RPT_JITTERY;
|
|
break;
|
|
case SRC_OK:
|
|
case SRC_BAD_STATS:
|
|
case SRC_UNREACHABLE:
|
|
report->state = RPT_UNREACH;
|
|
break;
|
|
case SRC_FALSETICKER:
|
|
report->state = RPT_FALSETICKER;
|
|
break;
|
|
case SRC_SELECTABLE:
|
|
report->state = RPT_CANDIDATE;
|
|
break;
|
|
default:
|
|
assert(0);
|
|
break;
|
|
}
|
|
/* Call stats module to fill out estimates */
|
|
SST_DoSourceReport(src->stats, report, now);
|
|
|
|
return 1;
|
|
}
|
|
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
SRC_ReportSourcestats(int index, RPT_SourcestatsReport *report, struct timeval *now)
|
|
{
|
|
SRC_Instance src;
|
|
|
|
if ((index >= n_sources) || (index < 0)) {
|
|
return 0;
|
|
} else {
|
|
src = sources[index];
|
|
report->ref_id = src->ref_id;
|
|
if (src->ip_addr)
|
|
report->ip_addr = *src->ip_addr;
|
|
else
|
|
report->ip_addr.family = IPADDR_UNSPEC;
|
|
SST_DoSourcestatsReport(src->stats, report, now);
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
SRC_Type
|
|
SRC_GetType(int index)
|
|
{
|
|
if ((index >= n_sources) || (index < 0))
|
|
return -1;
|
|
return sources[index]->type;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
SRC_Skew_Direction SRC_LastSkewChange(SRC_Instance inst)
|
|
{
|
|
SRC_Skew_Direction result = SRC_Skew_Nochange;
|
|
|
|
switch (SST_LastSkewChange(inst->stats)) {
|
|
case SST_Skew_Decrease:
|
|
result = SRC_Skew_Decrease;
|
|
break;
|
|
case SST_Skew_Nochange:
|
|
result = SRC_Skew_Nochange;
|
|
break;
|
|
case SST_Skew_Increase:
|
|
result = SRC_Skew_Increase;
|
|
break;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
/* ================================================== */
|
|
|
|
int
|
|
SRC_Samples(SRC_Instance inst)
|
|
{
|
|
return SST_Samples(inst->stats);
|
|
}
|
|
|
|
/* ================================================== */
|