ntp_util.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

/*
 * ntp_util.c - stuff I didn't have any other place for
 */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include "ntpd.h"
#include "ntp_io.h"
#include "ntp_unixtime.h"
#include "ntp_filegen.h"
#include "ntp_if.h"
#include "ntp_stdlib.h"

#include <stdio.h>
#include <ctype.h>
#include <sys/types.h>
#ifdef HAVE_SYS_IOCTL_H
# include <sys/ioctl.h>
#endif

#ifdef HAVE_IEEEFP_H
# include <ieeefp.h>
#endif
#ifdef HAVE_MATH_H
# include <math.h>
#endif

#ifdef  DOSYNCTODR
# if !defined(VMS)
#  include <sys/resource.h>
# endif /* VMS */
#endif

#if defined(VMS)
# include <descrip.h>
#endif /* VMS */

/*
 * This contains odds and ends.  Right now the only thing you'll find
 * in here is the hourly stats printer and some code to support
 * rereading the keys file, but I may eventually put other things in
 * here such as code to do something with the leap bits.
 */
/*
 * Name of the keys file
 */
static	char *key_file_name;

/*
 * The name of the drift_comp file and the temporary.
 */
static	char *stats_drift_file;
static	char *stats_temp_file;

/*
 * Statistics file stuff
 */
#ifndef NTP_VAR
# ifndef SYS_WINNT
#  define NTP_VAR "/var/NTP/"		/* NOTE the trailing '/' */
# else
#  define NTP_VAR "c:\\var\\ntp\\"		/* NOTE the trailing '\\' */
# endif /* SYS_WINNT */
#endif

#ifndef MAXPATHLEN
# define MAXPATHLEN 256
#endif

static	char statsdir[MAXPATHLEN] = NTP_VAR;

static FILEGEN peerstats;
static FILEGEN loopstats;
static FILEGEN clockstats;
static FILEGEN rawstats;
static FILEGEN sysstats;
#ifdef OPENSSL
static FILEGEN cryptostats;
#endif /* OPENSSL */

/*
 * This controls whether stats are written to the fileset. Provided
 * so that ntpdc can turn off stats when the file system fills up. 
 */
int stats_control;

/*
 * Initial frequency offset later passed to the loopfilter.
 */
double	old_drift;

/*
 * init_util - initialize the utilities
 */
void
init_util(void)
{
	stats_drift_file = 0;
	stats_temp_file = 0;
	key_file_name = 0;

	filegen_register(&statsdir[0], "peerstats", &peerstats);

	filegen_register(&statsdir[0], "loopstats", &loopstats);

	filegen_register(&statsdir[0], "clockstats", &clockstats);

	filegen_register(&statsdir[0], "rawstats", &rawstats);

	filegen_register(&statsdir[0], "sysstats", &sysstats);

#ifdef OPENSSL
	filegen_register(&statsdir[0], "cryptostats", &cryptostats);
#endif /* OPENSSL */

}


/*
 * hourly_stats - print some interesting stats
 */
void
hourly_stats(void)
{
	FILE *fp;

#ifdef DOSYNCTODR
	struct timeval tv;
#if !defined(VMS)
	int prio_set;
#endif
#ifdef HAVE_GETCLOCK
        struct timespec ts;
#endif
	int o_prio;

	/*
	 * Sometimes having a Sun can be a drag.
	 *
	 * The kernel variable dosynctodr controls whether the system's
	 * soft clock is kept in sync with the battery clock. If it
	 * is zero, then the soft clock is not synced, and the battery
	 * clock is simply left to rot. That means that when the system
	 * reboots, the battery clock (which has probably gone wacky)
	 * sets the soft clock. That means ntpd starts off with a very
	 * confused idea of what time it is. It then takes a large
	 * amount of time to figure out just how wacky the battery clock
	 * has made things drift, etc, etc. The solution is to make the
	 * battery clock sync up to system time. The way to do THAT is
	 * to simply set the time of day to the current time of day, but
	 * as quickly as possible. This may, or may not be a sensible
	 * thing to do.
	 *
	 * CAVEAT: settimeofday() steps the sun clock by about 800 us,
	 *         so setting DOSYNCTODR seems a bad idea in the
	 *         case of us resolution
	 */

#if !defined(VMS)
	/* (prr) getpriority returns -1 on error, but -1 is also a valid
	 * return value (!), so instead we have to zero errno before the
	 * call and check it for non-zero afterwards.
	 */
	errno = 0;
	prio_set = 0;
	o_prio = getpriority(PRIO_PROCESS,0); /* Save setting */

	/*
	 * (prr) if getpriority succeeded, call setpriority to raise
	 * scheduling priority as high as possible.  If that succeeds
	 * as well, set the prio_set flag so we remember to reset
	 * priority to its previous value below.  Note that on Solaris
	 * 2.6 (and beyond?), both getpriority and setpriority will fail
	 * with ESRCH, because sched_setscheduler (called from main) put
	 * us in the real-time scheduling class which setpriority
	 * doesn't know about. Being in the real-time class is better
	 * than anything setpriority can do, anyhow, so this error is
	 * silently ignored.
	 */
	if ((errno == 0) && (setpriority(PRIO_PROCESS,0,-20) == 0))
		prio_set = 1;	/* overdrive */
#endif /* VMS */
#ifdef HAVE_GETCLOCK
        (void) getclock(TIMEOFDAY, &ts);
        tv.tv_sec = ts.tv_sec;
        tv.tv_usec = ts.tv_nsec / 1000;
#else /*  not HAVE_GETCLOCK */
	GETTIMEOFDAY(&tv,(struct timezone *)NULL);
#endif /* not HAVE_GETCLOCK */
	if (ntp_set_tod(&tv,(struct timezone *)NULL) != 0) {
		msyslog(LOG_ERR, "can't sync battery time: %m");
	}
#if !defined(VMS)
	if (prio_set)
		setpriority(PRIO_PROCESS, 0, o_prio); /* downshift */
#endif /* VMS */
#endif /* DOSYNCTODR */

	NLOG(NLOG_SYSSTATIST)
		msyslog(LOG_INFO,
		    "offset %.6f sec freq %.3f ppm error %.6f poll %d",
		    last_offset, drift_comp * 1e6, sys_jitter,
		    sys_poll);

	
	record_sys_stats();
	if (stats_drift_file != 0) {
		if ((fp = fopen(stats_temp_file, "w")) == NULL) {
			msyslog(LOG_ERR, "can't open %s: %m",
			    stats_temp_file);
			return;
		}
		fprintf(fp, "%.3f\n", drift_comp * 1e6);
		(void)fclose(fp);
		/* atomic */
#ifdef SYS_WINNT
		(void) _unlink(stats_drift_file); /* rename semantics differ under NT */
#endif /* SYS_WINNT */

#ifndef NO_RENAME
		(void) rename(stats_temp_file, stats_drift_file);
#else
		/* we have no rename NFS of ftp in use */
		if ((fp = fopen(stats_drift_file, "w")) == NULL) {
			msyslog(LOG_ERR, "can't open %s: %m",
			    stats_drift_file);
			return;
		}

#endif

#if defined(VMS)
		/* PURGE */
		{
			$DESCRIPTOR(oldvers,";-1");
			struct dsc$descriptor driftdsc = {
				strlen(stats_drift_file),0,0,stats_drift_file };

			while(lib$delete_file(&oldvers,&driftdsc) & 1) ;
		}
#endif
	}
}


/*
 * stats_config - configure the stats operation
 */
void
stats_config(
	int item,
	char *invalue	/* only one type so far */
	)
{
	FILE *fp;
	char *value;
	int len;

	/*
	 * Expand environment strings under Windows NT, since the
	 * command interpreter doesn't do this, the program must.
	 */
#ifdef SYS_WINNT
	char newvalue[MAX_PATH], parameter[MAX_PATH];

	if (!ExpandEnvironmentStrings(invalue, newvalue, MAX_PATH)) {
 		switch(item) {
		    case STATS_FREQ_FILE:
			strcpy(parameter,"STATS_FREQ_FILE");
			break;
		    case STATS_STATSDIR:
			strcpy(parameter,"STATS_STATSDIR");
			break;
		    case STATS_PID_FILE:
			strcpy(parameter,"STATS_PID_FILE");
			break;
		    default:
			strcpy(parameter,"UNKNOWN");
			break;
		}
		value = invalue;

		msyslog(LOG_ERR,
		    "ExpandEnvironmentStrings(%s) failed: %m\n", parameter);
	} else {
		value = newvalue;
	}
#else    
	value = invalue;
#endif /* SYS_WINNT */

	switch(item) {
	    case STATS_FREQ_FILE:
		if (stats_drift_file != 0) {
			(void) free(stats_drift_file);
			(void) free(stats_temp_file);
			stats_drift_file = 0;
			stats_temp_file = 0;
		}

		if (value == 0 || (len = strlen(value)) == 0)
		    break;

		stats_drift_file = (char*)emalloc((u_int)(len + 1));
#if !defined(VMS)
		stats_temp_file = (char*)emalloc((u_int)(len +
		    sizeof(".TEMP")));
#else
		stats_temp_file = (char*)emalloc((u_int)(len +
		    sizeof("-TEMP")));
#endif /* VMS */
		memmove(stats_drift_file, value, (unsigned)(len+1));
		memmove(stats_temp_file, value, (unsigned)len);
#if !defined(VMS)
		memmove(stats_temp_file + len, ".TEMP",
		    sizeof(".TEMP"));
#else
		memmove(stats_temp_file + len, "-TEMP",
		    sizeof("-TEMP"));
#endif /* VMS */

		/*
		 * Open drift file and read frequency. If the file is
		 * missing or contains errors, tell the loop to reset.
		 */
		if ((fp = fopen(stats_drift_file, "r")) == NULL) {
			old_drift = 1e9;
			break;
		}
		if (fscanf(fp, "%lf", &old_drift) != 1) {
			msyslog(LOG_ERR, "Frequency format error in %s", 
			    stats_drift_file);
			old_drift = 1e9;
			break;
		}
		fclose(fp);
		msyslog(LOG_INFO,
		    "frequency initialized %.3f PPM from %s",
			old_drift, stats_drift_file);
		break;
	
	    case STATS_STATSDIR:
		if (strlen(value) >= sizeof(statsdir)) {
			msyslog(LOG_ERR,
			    "value for statsdir too long (>%d, sigh)",
			    (int)sizeof(statsdir)-1);
		} else {
			l_fp now;

			get_systime(&now);
			strcpy(statsdir,value);
			if(peerstats.prefix == &statsdir[0] &&
			    peerstats.fp != NULL) {
				fclose(peerstats.fp);
				peerstats.fp = NULL;
				filegen_setup(&peerstats, now.l_ui);
			}
			if(loopstats.prefix == &statsdir[0] &&
			    loopstats.fp != NULL) {
				fclose(loopstats.fp);
				loopstats.fp = NULL;
				filegen_setup(&loopstats, now.l_ui);
			}
			if(clockstats.prefix == &statsdir[0] &&
			    clockstats.fp != NULL) {
				fclose(clockstats.fp);
				clockstats.fp = NULL;
				filegen_setup(&clockstats, now.l_ui);
			}