/*
 * 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 "ntp_assert.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 */

/*
 * Defines used by the leapseconds stuff
 */
#define	MAX_TAI	100			/* max TAI offset (s) */
#define	L_DAY	86400UL			/* seconds per day */
#define	L_YEAR	(L_DAY * 365)		/* days per year */
#define	L_LYEAR	(L_YEAR + L_DAY)	/* days per leap year */
#define	L_4YEAR	(L_LYEAR + 3 * L_YEAR)	/* days per leap cycle */
#define	L_CENT	(L_4YEAR * 25)		/* days per century */

/*
 * This contains odds and ends, including the hourly stats, various
 * configuration items, leapseconds stuff, etc.
 */
/*
 * File names
 */
static	char *key_file_name;		/* keys file name */
char	*leapseconds_file_name;		/* leapseconds file name */
char	*stats_drift_file;		/* frequency file name */
static	char *stats_temp_file;		/* temp frequency file name */
double wander_resid;			/* wander threshold */
double	wander_threshold = 1e-7;	/* initial wander threshold */
int	drift_file_sw;			/* clock update switch */

/*
 * 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

#ifdef DEBUG_TIMING
static FILEGEN timingstats;
#endif
#ifdef OPENSSL
static FILEGEN cryptostats;
#endif /* OPENSSL */

static	char statsdir[MAXPATHLEN] = NTP_VAR;
static FILEGEN peerstats;
static FILEGEN loopstats;
static FILEGEN clockstats;
static FILEGEN rawstats;
static FILEGEN sysstats;
static FILEGEN protostats;

/*
 * 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 = 1e9;		/* current frequency */
static double prev_drift_comp;		/* last frequency update */

/*
 * Static prototypes
 */
static int leap_file(FILE *);
static void record_sys_stats(void);

/* 
 * Prototypes
 */
#ifdef DEBUG
void	uninit_util(void);
#endif


/*
 * uninit_util - free memory allocated by init_util
 */
#ifdef DEBUG
void
uninit_util(void)
{
#if defined(_MSC_VER) && defined (_DEBUG)
	_CrtCheckMemory();
#endif
	if (stats_drift_file) {
		free(stats_drift_file);
		free(stats_temp_file);
		stats_drift_file = NULL;
		stats_temp_file = NULL;
	}
	if (key_file_name) {
		free(key_file_name);
		key_file_name = NULL;
	}
	filegen_unregister("peerstats");
	filegen_unregister("loopstats");
	filegen_unregister("clockstats");
	filegen_unregister("rawstats");
	filegen_unregister("sysstats");
	filegen_unregister("protostats");
#ifdef OPENSSL
	filegen_unregister("cryptostats");
#endif /* OPENSSL */
#ifdef DEBUG_TIMING
	filegen_unregister("timingstats");
#endif /* DEBUG_TIMING */

#if defined(_MSC_VER) && defined (_DEBUG)
	_CrtCheckMemory();
#endif
}
#endif /* DEBUG */


/*
 * init_util - initialize the utilities (ntpd included)
 */
void
init_util(void)
{
	stats_drift_file = NULL;
	stats_temp_file = NULL;
	key_file_name = NULL;
	filegen_register(statsdir, "peerstats",   &peerstats);
	filegen_register(statsdir, "loopstats",   &loopstats);
	filegen_register(statsdir, "clockstats",  &clockstats);
	filegen_register(statsdir, "rawstats",    &rawstats);
	filegen_register(statsdir, "sysstats",    &sysstats);
	filegen_register(statsdir, "protostats",  &protostats);
#ifdef OPENSSL
	filegen_register(statsdir, "cryptostats", &cryptostats);
#endif /* OPENSSL */
#ifdef DEBUG_TIMING
	filegen_register(statsdir, "timingstats", &timingstats);
#endif /* DEBUG_TIMING */
#ifdef DEBUG
	atexit(uninit_util);
#endif /* DEBUG */
}


/*
 * hourly_stats - print some interesting stats
 */
void
write_stats(void)
{
	FILE	*fp;
	double	ftemp;
#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 */
	record_sys_stats();
	ftemp = fabs(prev_drift_comp - drift_comp); 
	prev_drift_comp = drift_comp;
	if (ftemp > clock_phi)
		return;

	if (stats_drift_file != 0 && drift_file_sw) {

		/*
		 * When the frequency file is written, initialize the
		 * wander threshold to a configured initial value.
		 * Thereafter reduce it by a factor of 0.5. When it
		 * drops below the frequency wander, write the frequency
		 * file. This adapts to the prevailing wander yet
		 * minimizes the file writes.
		 */
		drift_file_sw = FALSE;
		wander_resid *= 0.5;
#ifdef DEBUG
		if (debug)
			printf("write_stats: wander %.6lf thresh %.6lf, freq %.6lf\n",
			    clock_stability * 1e6, wander_resid * 1e6,
			    drift_comp * 1e6);
#endif
 		if (sys_leap != LEAP_NOTINSYNC && clock_stability >
		    wander_resid) {
			wander_resid = wander_threshold;
			if ((fp = fopen(stats_temp_file, "w")) == NULL)
			    {
				msyslog(LOG_ERR,
				    "frequency file %s: %m",
				    stats_temp_file);
				return;
			}
			fprintf(fp, "%.3f\n", drift_comp * 1e6);
			(void)fclose(fp);
			/* atomic */
#ifdef SYS_WINNT
			if (_unlink(stats_drift_file)) /* rename semantics differ under NT */
				msyslog(LOG_WARNING, 
					"Unable to remove prior drift file %s, %m", 
					stats_drift_file);
#endif /* SYS_WINNT */

#ifndef NO_RENAME
			if (rename(stats_temp_file, stats_drift_file))
				msyslog(LOG_WARNING, 
					"Unable to rename temp drift file %s to %s, %m", 
					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,
				    "frequency file %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
		} else {
			/* XXX: Log a message at INFO level */
		}
	}
}


/*
 * stats_config - configure the stats operation
 */
void
stats_config(
	int item,
	const char *invalue	/* only one type so far */
	)
{
	FILE	*fp;
	const char *value;
	int	len;
	char	tbuf[80];
	char	str1[20], str2[20];
#ifndef VMS
	const char temp_ext[] = ".TEMP";
#else
	const char temp_ext[] = "-TEMP";
#endif

	/*
	 * 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_LEAP_FILE:
			strcpy(parameter,"STATS_LEAP_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) {

	/*
	 * Open and read frequency file.
	 */
	case STATS_FREQ_FILE:
		if (!value || (len = strlen(value)) == 0)
			break;

		stats_drift_file = erealloc(stats_drift_file, len + 1);
		stats_temp_file = erealloc(stats_temp_file, 
					   len + sizeof(".TEMP"));

		memcpy(stats_drift_file, value, (unsigned)(len+1));
		memcpy(stats_temp_file, value, (unsigned)len);
		memcpy(stats_temp_file + len, temp_ext,
		       sizeof(temp_ext));

		/*
		 * 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)
			break;

		if (fscanf(fp, "%lf", &old_drift) != 1) {
			msyslog(LOG_ERR,
				"format error frequency file %s", 
				stats_drift_file);
			fclose(fp);
			break;

		}
		fclose(fp);
		old_drift /= 1e6;
		prev_drift_comp = old_drift;
		break;

	/*
	 * Specify statistics directory.
	 */
	case STATS_STATSDIR:

		/*
		 * HMS: the following test is insufficient:
		 * - value may be missing the DIR_SEP
		 * - we still need the filename after it
		 */
		if (strlen(value) >= sizeof(statsdir)) {
			msyslog(LOG_ERR,
			    "statsdir too long (>%d, sigh)",
			    (int)sizeof(statsdir) - 1);
		} else {
			l_fp now;
			int add_dir_sep;
			int value_l = strlen(value);

			/* Add a DIR_SEP unless we already have one. */
			if (value_l == 0)
				add_dir_sep = 0;
			else
				add_dir_sep = (DIR_SEP !=
				    value[value_l - 1]);

			if (add_dir_sep)
			    snprintf(statsdir, sizeof(statsdir),
				"%s%c", value, DIR_SEP);
			else
			    snprintf(statsdir, sizeof(statsdir),
				"%s", value);

			get_systime(&now);
			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);
			}
			if(rawstats.prefix == &statsdir[0] &&
			    rawstats.fp != NULL) {
				fclose(rawstats.fp);
				rawstats.fp = NULL;
				filegen_setup(&rawstats, now.l_ui);
			}
			if(sysstats.prefix == &statsdir[0] &&
			    sysstats.fp != NULL) {
				fclose(sysstats.fp);
				sysstats.fp = NULL;
				filegen_setup(&sysstats, now.l_ui);
			}
			if(protostats.prefix == &statsdir[0] &&
			    protostats.fp != NULL) {
				fclose(protostats.fp);
				protostats.fp = NULL;
				filegen_setup(&protostats, now.l_ui);
			}
#ifdef OPENSSL
			if(cryptostats.prefix == &statsdir[0] &&
			    cryptostats.fp != NULL) {
				fclose(cryptostats.fp);
				cryptostats.fp = NULL;
				filegen_setup(&cryptostats, now.l_ui);
			}
#endif /* OPENSSL */
#ifdef DEBUG_TIMING
			if(timingstats.prefix == &statsdir[0] &&
			    timingstats.fp != NULL) {
				fclose(timingstats.fp);
				timingstats.fp = NULL;
				filegen_setup(&timingstats, now.l_ui);
			}
#endif /* DEBUG_TIMING */
		}
		break;

	/*
	 * Open pid file.
	 */
	case STATS_PID_FILE:
		if ((fp = fopen(value, "w")) == NULL) {
			msyslog(LOG_ERR, "pid file %s: %m",
			    value);
			break;
		}
		fprintf(fp, "%d", (int)getpid());
		fclose(fp);;
		break;

	/*
	 * Read leapseconds file.
	 */
	case STATS_LEAP_FILE:
		if ((fp = fopen(value, "r")) == NULL) {
			msyslog(LOG_ERR, "leapseconds file %s: %m",
			    value);
			break;
		}

		if (leap_file(fp) < 0) {
			msyslog(LOG_ERR,
			    "format error leapseconds file %s",
			    value);
		} else {
			strcpy(str1, fstostr(leap_sec));
			strcpy(str2, fstostr(leap_expire));
			snprintf(tbuf, sizeof(tbuf),
			    "%d leap %s expire %s", leap_tai, str1,
			    str2);
			report_event(EVNT_TAI, NULL, tbuf);
		}
		fclose(fp);
		break;

	default:
		/* oh well */
		break;
	}
}


/*
 * record_peer_stats - write peer statistics to file
 *
 * file format:
 * day (MJD)
 * time (s past UTC midnight)
 * IP address
 * status word (hex)
 * offset
 * delay
 * dispersion
 * jitter
*/
void
record_peer_stats(
	sockaddr_u *addr,
	int	status,
	double	offset,		/* offset */
	double	delay,		/* delay */
	double	dispersion,	/* dispersion */
	double	jitter		/* jitter */
	)
{
	l_fp	now;
	u_long	day;

	if (!stats_control)
		return;

	get_systime(&now);
	filegen_setup(&peerstats, now.l_ui);
	day = now.l_ui / 86400 + MJD_1900;
	now.l_ui %= 86400;
	if (peerstats.fp != NULL) {
		fprintf(peerstats.fp,
		    "%lu %s %s %x %.9f %.9f %.9f %.9f\n", day,
		    ulfptoa(&now, 3), stoa(addr), status, offset,
		    delay, dispersion, jitter);
		fflush(peerstats.fp);
	}
}


/*
 * record_loop_stats - write loop filter statistics to file
 *
 * file format:
 * day (MJD)
 * time (s past midnight)
 * offset
 * frequency (PPM)
 * jitter
 * wnder (PPM)
 * time constant (log2)
 */
void
record_loop_stats(
	double	offset,		/* offset */
	double	freq,		/* frequency (PPM) */
	double	jitter,		/* jitter */
	double	wander,		/* wander (PPM) */
	int spoll
	)
{
	l_fp	now;
	u_long	day;

	if (!stats_control)
		return;

	get_systime(&now);
	filegen_setup(&loopstats, now.l_ui);
	day = now.l_ui / 86400 + MJD_1900;
	now.l_ui %= 86400;
	if (loopstats.fp != NULL) {
		fprintf(loopstats.fp, "%lu %s %.9f %.3f %.9f %.6f %d\n",
		    day, ulfptoa(&now, 3), offset, freq * 1e6, jitter,
		    wander * 1e6, spoll);
		fflush(loopstats.fp);
	}
}


/*
 * record_clock_stats - write clock statistics to file
 *
 * file format:
 * day (MJD)
 * time (s past midnight)
 * IP address
 * text message
 */
void
record_clock_stats(
	sockaddr_u *addr,
	const char *text	/* timecode string */
	)
{
	l_fp	now;
	u_long	day;

	if (!stats_control)
		return;

	get_systime(&now);
	filegen_setup(&clockstats, now.l_ui);
	day = now.l_ui / 86400 + MJD_1900;
	now.l_ui %= 86400;
	if (clockstats.fp != NULL) {
		fprintf(clockstats.fp, "%lu %s %s %s\n", day,
		    ulfptoa(&now, 3), stoa(addr), text);
		fflush(clockstats.fp);
	}
}


/*
 * record_raw_stats - write raw timestamps to file
 *
 * file format
 * day (MJD)
 * time (s past midnight)
 * peer ip address
 * IP address
 * t1 t2 t3 t4 timestamps
 */
void
record_raw_stats(
	sockaddr_u *srcadr,
	sockaddr_u *dstadr,
	l_fp	*t1,		/* originate timestamp */
	l_fp	*t2,		/* receive timestamp */
	l_fp	*t3,		/* transmit timestamp */
	l_fp	*t4		/* destination timestamp */
	)
{
	l_fp	now;
	u_long	day;

	if (!stats_control)
		return;

	get_systime(&now);
	filegen_setup(&rawstats, now.l_ui);
	day = now.l_ui / 86400 + MJD_1900;
	now.l_ui %= 86400;
	if (rawstats.fp != NULL) {
		fprintf(rawstats.fp, "%lu %s %s %s %s %s %s %s\n", day,
		    ulfptoa(&now, 3), stoa(srcadr), dstadr ? 
		    stoa(dstadr) : "-",	ulfptoa(t1, 9), ulfptoa(t2, 9),
		    ulfptoa(t3, 9), ulfptoa(t4, 9));
		fflush(rawstats.fp);
	}
}


/*
 * record_sys_stats - write system statistics to file
 *
 * file format
 * day (MJD)
 * time (s past midnight)
 * time since reset
 * packets recieved
 * packets for this host
 * current version
 * old version
 * access denied
 * bad length or format
 * bad authentication
 * declined
 * rate exceeded
 * KoD sent
 */
void
record_sys_stats(void)
{
	l_fp	now;
	u_long	day;

	if (!stats_control)
		return;

	get_systime(&now);
	filegen_setup(&sysstats, now.l_ui);
	day = now.l_ui / 86400 + MJD_1900;
	now.l_ui %= 86400;
	if (sysstats.fp != NULL) {
		fprintf(sysstats.fp,
		    "%lu %s %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu\n",
		    day, ulfptoa(&now, 3), current_time - sys_stattime,
		    sys_received, sys_processed, sys_newversion,
		    sys_oldversion, sys_restricted, sys_badlength,
		    sys_badauth, sys_declined, sys_limitrejected,
		    sys_kodsent);
		fflush(sysstats.fp);
		proto_clr_stats();
	}
}


/*
 * record_proto_stats - write system statistics to file
 *
 * file format
 * day (MJD)
 * time (s past midnight)
 * text message
 */
void
record_proto_stats(
	char	*str		/* text string */
	)
{
	l_fp	now;
	u_long	day;

	if (!stats_control)
		return;

	get_systime(&now);
	filegen_setup(&protostats, now.l_ui);
	day = now.l_ui / 86400 + MJD_1900;
	now.l_ui %= 86400;
	if (protostats.fp != NULL) {
		fprintf(protostats.fp, "%lu %s %s\n", day,
		    ulfptoa(&now, 3), str);
		fflush(protostats.fp);
	}
}


#ifdef OPENSSL
/*
 * record_crypto_stats - write crypto statistics to file
 *
 * file format:
 * day (mjd)
 * time (s past midnight)
 * peer ip address
 * text message
 */
void
record_crypto_stats(
	sockaddr_u *addr,
	const char *text	/* text message */
	)
{
	l_fp	now;
	u_long	day;

	if (!stats_control)
		return;

	get_systime(&now);
	filegen_setup(&cryptostats, now.l_ui);
	day = now.l_ui / 86400 + MJD_1900;
	now.l_ui %= 86400;
	if (cryptostats.fp != NULL) {
		if (addr == NULL)
			fprintf(cryptostats.fp, "%lu %s 0.0.0.0 %s\n",
			    day, ulfptoa(&now, 3), text);
		else
			fprintf(cryptostats.fp, "%lu %s %s %s\n",
			    day, ulfptoa(&now, 3), stoa(addr), text);
		fflush(cryptostats.fp);
	}
}
#endif /* OPENSSL */


#ifdef DEBUG_TIMING
/*
 * record_timing_stats - write timing statistics to file
 *
 * file format:
 * day (mjd)
 * time (s past midnight)
 * text message
 */
void
record_timing_stats(
	const char *text	/* text message */
	)
{
	static unsigned int flshcnt;
	l_fp	now;
	u_long	day;

	if (!stats_control)
		return;

	get_systime(&now);
	filegen_setup(&timingstats, now.l_ui);
	day = now.l_ui / 86400 + MJD_1900;
	now.l_ui %= 86400;
	if (timingstats.fp != NULL) {
		fprintf(timingstats.fp, "%lu %s %s\n", day, lfptoa(&now,
		    3), text);
		if (++flshcnt % 100 == 0)
			fflush(timingstats.fp);
	}
}
#endif


/*
 * leap_file - read leapseconds file
 *
 * Read the ERTS leapsecond file in NIST text format and extract the
 * NTP seconds of the latest leap and TAI offset after the leap.
 */
static int
leap_file(
	FILE	*fp		/* file handle */
	)
{
	char	buf[NTP_MAXSTRLEN]; /* file line buffer */
	u_long	leap;		/* NTP time at leap */
	u_long	expire;		/* NTP time when file expires */
	int	offset;		/* TAI offset at leap (s) */
	int	i;

	/*
	 * Read and parse the leapseconds file. Empty lines and comments
	 * are ignored. A line beginning with #@ contains the file
	 * expiration time in NTP seconds. Other lines begin with two
	 * integers followed by junk or comments. The first integer is
	 * the NTP seconds at the leap, the second is the TAI offset
	 * after the leap.
 	 */
	offset = 0;
	leap = 0;
	expire = 0;
	i = 10;
	while (fgets(buf, NTP_MAXSTRLEN - 1, fp) != NULL) {
		if (strlen(buf) < 1)
			continue;

		if (buf[0] == '#') {
			if (strlen(buf) < 3)
				continue;

			/*
			 * Note the '@' flag was used only in the 2006
			 * table; previious to that the flag was '$'.
			 */
			if (buf[1] == '@' || buf[1] == '$') {
				if (sscanf(&buf[2], "%lu", &expire) !=
				    1)
					return (-1);

				continue;
			}
		}
		if (sscanf(buf, "%lu %d", &leap, &offset) == 2) {

			/*
			 * Valid offsets must increase by one for each
			 * leap.
			 */
			if (i++ != offset)
				return (-1);
		}
	}

	/*
	 * There must be at least one leap.
	 */
	if (i == 10)
		return (-1);

	leap_tai = offset;
	leap_sec = leap;
	leap_expire = expire;
	return (0);
}


/*
 * leap_month - returns seconds until the end of the month.
 */
u_long
leap_month(
	u_long	sec		/* current NTP second */
	)
{
	u_long	ltemp;
	u_long	*ptr;
	u_long	year[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30,
		    31}; 
	u_long	lyear[] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30,
		    31}; 

	/*
	 * Find current leap cycle.
	 */
	ltemp = sec;
	while (ltemp >= L_CENT)
		ltemp -= L_CENT;
	while (ltemp >= L_4YEAR)
		ltemp -= L_4YEAR;

	/*
	 * We are within four years of the target. If in leap year, use
	 * leap year month table; otherwise, use year month table.
	 */
	if (ltemp < L_LYEAR) {
		ptr = lyear;
	} else {
		ptr = year;
		ltemp -= L_LYEAR;
		while (ltemp >= L_YEAR)
			ltemp -= L_YEAR;
	}

	/*
	 * We are within one year of the target. Find the month of the
	 * leap.
	 */
	while (ltemp >= *ptr * L_DAY)
		ltemp -= *ptr++ * L_DAY;

	/*
	 * The result is the number of seconds until the end of the
	 * month when the leap is to occur.
	 */
	return (*ptr * L_DAY - ltemp - L_DAY);
}


/*
 * getauthkeys - read the authentication keys from the specified file
 */
void
getauthkeys(
	const char *keyfile
	)
{
	int len;

	len = strlen(keyfile);
	if (!len)
		return;
	
#ifndef SYS_WINNT
	key_file_name = erealloc(key_file_name, len + 1);
	memmove(key_file_name, keyfile, len + 1);
#else
	key_file_name = erealloc(key_file_name, _MAX_PATH);
	if (len + 1 > _MAX_PATH)
		return;
	if (!ExpandEnvironmentStrings(keyfile, key_file_name,
				      _MAX_PATH)) {
		msyslog(LOG_ERR,
			"ExpandEnvironmentStrings(KEY_FILE) failed: %m");
		strncpy(key_file_name, keyfile, _MAX_PATH);
	}
#endif /* SYS_WINNT */

	authreadkeys(key_file_name);
}


/*
 * rereadkeys - read the authentication key file over again.
 */
void
rereadkeys(void)
{
	if (NULL != key_file_name)
		authreadkeys(key_file_name);
}


/*
 * sock_hash - hash a sockaddr_u structure
 */
u_short
sock_hash(
	sockaddr_u *addr
	)
{
	u_int hashVal;
	u_int j;
	size_t len;
	u_char *pch;
	hashVal = 0;
	len = 0;

	/*
	 * We can't just hash the whole thing because there are hidden
	 * fields in sockaddr_in6 that might be filled in by recvfrom(),
	 * so just use the family, port and address.
	 */
	pch = (u_char *)&AF(addr);
	hashVal = 37 * hashVal + *pch;
	if (sizeof(AF(addr)) > 1) {
		pch++;
		hashVal = 37 * hashVal + *pch;
	}
	switch(AF(addr)) {
	case AF_INET:
		pch = (u_char *)&SOCK_ADDR4(addr);
		len = sizeof(SOCK_ADDR4(addr));
		break;

	case AF_INET6:
		pch = (u_char *)&SOCK_ADDR6(addr);
		len = sizeof(SOCK_ADDR6(addr));
		break;
	}

	for (j = 0; j < len ; j++)
		hashVal = 37 * hashVal + pch[j];

	hashVal = hashVal & NTP_HASH_MASK;

	return (u_short)hashVal;
}


#if notyet
/*
 * ntp_exit - document explicitly that ntpd has exited
 */
void
ntp_exit(int retval)
{
	msyslog(LOG_ERR, "EXITING with return code %d", retval);
	exit(retval);
}
#endif

/*
 * fstostr - prettyprint NTP seconds
 */
char * fstostr(
	time_t	ntp_stamp
	)
{
	static char	str[20];
	struct tm *	tm;
	time_t		unix_stamp;

	unix_stamp = ntp_stamp - JAN_1970;
	tm = gmtime(&unix_stamp);
	if (NULL != tm)
		snprintf(str, sizeof(str),
			 "%04d%02d%02d%02d%02d",
			 tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
			 tm->tm_hour, tm->tm_min);
	else
		strcpy(str, "gmtime() error");

	return str;
}