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sntp 根据简单网络时间同步协议实现的客户端和服务器程序.

-*- outline -*-

* What's this?

This is an easy-to-use SNTP (RFC 2030) server/client which is suitable
for a small LAN to synchronize the system clocks of each host.

* Requirements

- Basic Socket Interface Extensions for IPv6 (RFC 3493)
- get/settimeofday(2), adjtime(2)

* Quickstart

** Client

At first, obtain an estimated current time from your favorite NTP/SNTP
server.  For example:

	$ psntpdate time.nist.gov
	Fri Apr 11 11:09:22 JST 2003

If the time shown seems reasonable enough, set it to the system clock.

	$ psntpdate -r time.nist.gov

You may get an error if the system clock hasn't been calibrated yet.
It could be forced by the -f option.

	$ psntpdate -r -f time.nist.gov

Then you need to adjust the system clock periodically by running
"psntpdate -a" from cron.  Here's a sample crontab entry.

	13	*	*	*	*	root	/usr/local/sbin/psntpdate -a time.nist.gov >/dev/null

Note that "psntpdate -a" doesn't change the clock immediately; it's
just an interface to the adjtime system call.  See adjtime(2) for
details.

** Server

Add the following line to your /etc/inetd.conf.

	ntp	dgram	udp	wait	root	/usr/local/libexec/psntpd	psntpd

Or, if you want an IPv6 server:

	ntp	dgram	udp6	wait	root	/usr/local/libexec/psntpd	psntpd

And restart the inetd.

	$ killall -HUP inetd

* TODO

No major functional changes, mostly bug fixes and portability
improvements only.