1.\" 2.\" Copyright (c) 2003 Tom Rhodes 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD: src/lib/libc/sys/ntp_adjtime.2,v 1.1.2.1 2003/04/22 17:31:18 trhodes Exp $ 27.\" $DragonFly: src/lib/libc/sys/ntp_adjtime.2,v 1.3 2004/03/11 12:28:51 hmp Exp $ 28.\" 29.Dd April 1, 2003 30.Dt NTP_ADJTIME 2 31.Os 32.Sh NAME 33.Nm ntp_adjtime 34.Nd NTP daemon application interface 35.Sh SYNOPSIS 36.In sys/types.h 37.In sys/timex.h 38.Ft int 39.Fn ntp_adjtime "struct timex *tp" 40.Sh DESCRIPTION 41The 42.Fn ntp_adjtime 43system call is used as a kernel interface 44for the Network Time Protocol daemon, 45.Xr ntpd 8 . 46Certain fields of the 47.Vt timex 48structure are interpreted in either 49microseconds or nanoseconds, according to the state of the 50.Dv STA_NANO 51bit in the 52.Va status 53word. 54.Pp 55In the 56.Dx 57kernel, the 58.Fn ntp_adjtime 59and 60.Xr ntp_gettime 2 61system calls can be used to determine which 62resolution is in use, and to select either one at any time. 63The resolution selected affects the scaling of certain fields in the 64.Fn ntp_gettime 65and 66.Fn ntp_adjtime 67system calls. 68.Pp 69Take note that this 70.Tn API 71is extremely complex and stateful. 72Users should not attempt modification without first 73reviewing the 74.Xr ntpd 8 75sources in depth. 76.Bd -literal 77/* 78 * NTP daemon interface (ntp_adjtime()) - used to discipline CPU clock 79 * oscillator and determine status. 80 * 81 * Note: The offset, precision and jitter members are in microseconds if 82 * STA_NANO is zero and nanoseconds if not. 83 */ 84struct timex { 85 unsigned int modes; /* clock mode bits (wo) */ 86 long offset; /* time offset (ns/us) (rw) */ 87 long freq; /* frequency offset (scaled PPM) (rw) */ 88 long maxerror; /* maximum error (us) (rw) */ 89 long esterror; /* estimated error (us) (rw) */ 90 int status; /* clock status bits (rw) */ 91 long constant; /* poll interval (log2 s) (rw) */ 92 long precision; /* clock precision (ns/us) (ro) */ 93 long tolerance; /* clock frequency tolerance (scaled 94 * PPM) (ro) */ 95 /* 96 * The following read-only structure members are implemented 97 * only if the PPS signal discipline is configured in the 98 * kernel. They are included in all configurations to insure 99 * portability. 100 */ 101 long ppsfreq; /* PPS frequency (scaled PPM) (ro) */ 102 long jitter; /* PPS jitter (ns/us) (ro) */ 103 int shift; /* interval duration (s) (shift) (ro) */ 104 long stabil; /* PPS stability (scaled PPM) (ro) */ 105 long jitcnt; /* jitter limit exceeded (ro) */ 106 long calcnt; /* calibration intervals (ro) */ 107 long errcnt; /* calibration errors (ro) */ 108 long stbcnt; /* stability limit exceeded (ro) */ 109}; 110.Ed 111.Pp 112Upon successful completion, 113.Fn ntp_adjtime 114will fill the 115.Fa tp 116argument with the current clock state. 117.Sh RETURN VALUES 118.Rv -std ntp_adjtime 119.Pp 120Possible states of the clock are: 121.Pp 122.Bl -tag -compact -width ".Dv TIME_ERROR" 123.It Dv TIME_OK 124Everything okay, no leap second warning. 125.It Dv TIME_INS 126insert leap second warning. 127.It Dv TIME_DEL 128delete leap second warning. 129.It Dv TIME_OOP 130Leap second in progress. 131.It Dv TIME_WAIT 132Leap second has occurred. 133.It Dv TIME_ERROR 134Clock not synchronized. 135.El 136.Sh ERRORS 137The 138.Fn ntp_gettime 139system call may return 140.Er EPERM 141if the caller 142does not have sufficient permissions. 143.Sh SEE ALSO 144.Xr ntp_gettime 2 , 145.Xr ntpd 8 146.Sh AUTHORS 147This manual page was written by 148.An Tom Rhodes Aq trhodes@FreeBSD.org . 149