add a new -s option, that tells ntpd to set the time using settimeofday()

once at startup. ntpd delays daemonizing until it has done the intial
time setting (or ran into the timeout) in this mode to make sure stuff started
later in rc is not subject to time jumps.
this eleminates the need to run rdate -n beforehands.
with some input from & ok ryan and bob, march music from mickey

src/usr.sbin/ntpd/client.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: client.c,v 1.33 2004/09/14 22:01:28 henning Exp $ */
+/*	$OpenBSD: client.c,v 1.34 2004/09/18 20:01:38 henning Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -154,7 +154,7 @@ client_query(struct ntp_peer *p)
 }
 
 int
-client_dispatch(struct ntp_peer *p)
+client_dispatch(struct ntp_peer *p, u_int8_t settime)
 {
 	struct sockaddr_storage	 fsa;
 	socklen_t		 fsa_len;
@@ -251,6 +251,8 @@ client_dispatch(struct ntp_peer *p)
 	}
 
 	client_update(p);
+	if (settime)
+		ntp_settime(p->reply[p->shift].offset);
 
 	log_debug("reply from %s: offset %f delay %f, "
 	    "next query %ds", log_sockaddr((struct sockaddr *)&fsa),

src/usr.sbin/ntpd/ntp.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntp.c,v 1.32 2004/09/18 07:33:14 henning Exp $ */
+/*	$OpenBSD: ntp.c,v 1.33 2004/09/18 20:01:38 henning Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -19,6 +19,8 @@
 
 #include <sys/param.h>
 #include <errno.h>
+#include <fcntl.h>
+#include <paths.h>
 #include <poll.h>
 #include <pwd.h>
 #include <signal.h>
@@ -56,7 +58,7 @@ ntp_sighdlr(int sig)
 pid_t
 ntp_main(int pipe_prnt[2], struct ntpd_conf *nconf)
 {
-	int			 nfds, i, j, idx_peers, timeout;
+	int			 nfds, i, j, idx_peers, timeout, nullfd;
 	u_int			 pfd_elms = 0, idx2peer_elms = 0;
 	u_int			 listener_cnt, new_cnt;
 	pid_t			 pid;
@@ -84,11 +86,21 @@ ntp_main(int pipe_prnt[2], struct ntpd_conf *nconf)
 	if ((pw = getpwnam(NTPD_USER)) == NULL)
 		fatal(NULL);
 
+	if ((nullfd = open(_PATH_DEVNULL, O_RDWR, 0)) == -1)
+		fatal(NULL);
+
 	if (chroot(pw->pw_dir) == -1)
 		fatal("chroot");
 	if (chdir("/") == -1)
 		fatal("chdir(\"/\")");
 
+	if (!nconf->debug) {
+		dup2(nullfd, STDIN_FILENO);
+		dup2(nullfd, STDOUT_FILENO);
+		dup2(nullfd, STDERR_FILENO);
+	}
+	close(nullfd);
+
 	setproctitle("ntp engine");
 
 	conf = nconf;
@@ -228,8 +240,8 @@ ntp_main(int pipe_prnt[2], struct ntpd_conf *nconf)
 		for (; nfds > 0 && j < i; j++)
 			if (pfd[j].revents & POLLIN) {
 				nfds--;
-				if (client_dispatch(idx2peer[j - idx_peers]) ==
-				     -1)
+				if (client_dispatch(idx2peer[j - idx_peers],
+				    conf->settime) == -1)
 					ntp_quit = 1;
 			}
 	}
@@ -361,6 +373,13 @@ ntp_adjtime(void)
 		p->update.good = 0;
 }
 
+void
+ntp_settime(double offset)
+{
+	imsg_compose(ibuf_main, IMSG_SETTIME, 0, 0, &offset, sizeof(offset));
+	conf->settime = 0;
+}
+
 void
 ntp_host_dns(char *name, u_int32_t peerid)
 {

src/usr.sbin/ntpd/ntpd.8

@@ -1,4 +1,4 @@
-.\" $OpenBSD: ntpd.8,v 1.5 2004/07/13 19:51:38 jmc Exp $
+.\" $OpenBSD: ntpd.8,v 1.6 2004/09/18 20:01:38 henning Exp $
 .\"
 .\" Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
 .\"
@@ -23,7 +23,7 @@
 .Sh SYNOPSIS
 .Nm ntpd
 .Bk -words
-.Op Fl d
+.Op Fl ds
 .Op Fl f Ar file
 .Ek
 .Sh DESCRIPTION
@@ -38,6 +38,10 @@ and the Network Time Protocol version 3,
 as described in RFC 1305.
 .Pp
 .Nm
+uses the
+.Xr adjtime 2 ,
+system call to correct the local system time without causing time jumps.
+.Nm
 is usually started at boot time, and can be enabled by
 setting the following in
 .Pa /etc/rc.conf.local :
@@ -71,6 +75,10 @@ Use
 as the configuration file,
 instead of the default
 .Pa /etc/ntpd.conf .
+.It Fl s
+Set the time immediately once at startup to allow for a large time correction,
+eleminating the need to run rdate before starting
+.Nm .
 .El
 .Sh FILES
 .Bl -tag -width "/etc/ntpd.confXXX" -compact

src/usr.sbin/ntpd/ntpd.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.c,v 1.17 2004/09/15 19:21:25 henning Exp $ */
+/*	$OpenBSD: ntpd.c,v 1.18 2004/09/18 20:01:38 henning Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -37,8 +37,9 @@ void	sighdlr(int);
 void	usage(void);
 int	main(int, char *[]);
 int	check_child(pid_t, const char *);
-int	dispatch_imsg(void);
+int	dispatch_imsg(struct ntpd_conf *);
 void	ntpd_adjtime(double);
+void	ntpd_settime(double);
 
 volatile sig_atomic_t	 quit = 0;
 volatile sig_atomic_t	 reconfig = 0;
@@ -67,7 +68,7 @@ usage(void)
 {
 	extern char *__progname;
 
-	fprintf(stderr, "usage: %s [-d] [-f file]\n", __progname);
+	fprintf(stderr, "usage: %s [-d] [-f file] [-s]\n", __progname);
 	exit(1);
 }
 
@@ -81,8 +82,7 @@ main(int argc, char *argv[])
 	struct pollfd		 pfd[POLL_MAX];
 	pid_t			 chld_pid = 0, pid;
 	char			*conffile;
-	int			 debug = 0;
-	int			 ch, nfds;
+	int			 ch, nfds, timeout = INFTIM;
 	int			 pipe_chld[2];
 
 	conffile = CONFFILE;
@@ -91,14 +91,17 @@ main(int argc, char *argv[])
 
 	log_init(1);		/* log to stderr until daemonized */
 
-	while ((ch = getopt(argc, argv, "df:")) != -1) {
+	while ((ch = getopt(argc, argv, "df:s")) != -1) {
 		switch (ch) {
 		case 'd':
-			debug = 1;
+			conf.debug = 1;
 			break;
 		case 'f':
 			conffile = optarg;
 			break;
+		case 's':
+			conf.settime = 1;
+			break;
 		default:
 			usage();
 			/* NOTREACHED */
@@ -119,10 +122,12 @@ main(int argc, char *argv[])
 	}
 	endpwent();
 
-	log_init(debug);
-
-	if (!debug)
-		daemon(1, 0);
+	if (!conf.settime) {
+		log_init(conf.debug);
+		if (!conf.debug)
+			daemon(1, 0);
+	} else
+		timeout = 15 * 1000;
 
 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_chld) == -1)
 		fatal("socketpair");
@@ -149,12 +154,22 @@ main(int argc, char *argv[])
 		if (ibuf->w.queued)
 			pfd[PFD_PIPE].events |= POLLOUT;
 
-		if ((nfds = poll(pfd, 1, INFTIM)) == -1)
+		if ((nfds = poll(pfd, 1, timeout)) == -1)
 			if (errno != EINTR) {
 				log_warn("poll error");
 				quit = 1;
 			}
 
+		if (nfds == 0 && conf.settime) {
+			log_debug("no reply received, skipping initial time"
+			    "setting");
+			conf.settime = 0;
+			timeout = INFTIM;
+			log_init(conf.debug);
+			if (!conf.debug)
+				daemon(1, 0);
+		}
+
 		if (nfds > 0 && (pfd[PFD_PIPE].revents & POLLOUT))
 			if (msgbuf_write(&ibuf->w) < 0) {
 				log_warn("pipe write error (to child");
@@ -163,7 +178,7 @@ main(int argc, char *argv[])
 
 		if (nfds > 0 && pfd[PFD_PIPE].revents & POLLIN) {
 			nfds--;
-			if (dispatch_imsg() == -1)
+			if (dispatch_imsg(&conf) == -1)
 				quit = 1;
 		}
 
@@ -213,7 +228,7 @@ check_child(pid_t pid, const char *pname)
 }
 
 int
-dispatch_imsg(void)
+dispatch_imsg(struct ntpd_conf *conf)
 {
 	struct imsg		 imsg;
 	int			 n, cnt;
@@ -244,6 +259,19 @@ dispatch_imsg(void)
 			memcpy(&d, imsg.data, sizeof(d));
 			ntpd_adjtime(d);
 			break;
+		case IMSG_SETTIME:
+			if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(d))
+				fatal("invalid IMSG_SETTIME received");
+			if (!conf->settime)
+				break;
+			memcpy(&d, imsg.data, sizeof(d));
+			ntpd_settime(d);
+			/* daemonize now */
+			log_init(conf->debug);
+			if (!conf->debug)
+				daemon(1, 0);
+			conf->settime = 0;
+			break;
 		case IMSG_HOST_DNS:
 			name = imsg.data;
 			if (imsg.hdr.len != strlen(name) + 1 + IMSG_HEADER_SIZE)
@@ -278,3 +306,27 @@ ntpd_adjtime(double d)
 	if (adjtime(&tv, NULL) == -1)
 		log_warn("adjtime failed");
 }
+
+void
+ntpd_settime(double d)
+{
+	struct timeval	tv, curtime;
+	char		buf[80];
+	time_t		tval;
+
+	d_to_tv(d, &tv);
+	if (gettimeofday(&curtime, NULL) == -1)
+		log_warn("gettimeofday");
+	curtime.tv_sec += tv.tv_sec;
+	curtime.tv_usec += tv.tv_usec;
+	if (curtime.tv_usec > 1000000) {
+		curtime.tv_sec++;
+		curtime.tv_usec -= 1000000;
+	}
+	if (settimeofday(&curtime, NULL) == -1)
+		log_warn("settimeofday");
+	tval = curtime.tv_sec;
+	strftime(buf, sizeof(buf), "%a %b %e %H:%M:%S %Z %Y",
+	    localtime(&tval));
+	log_info("set local clock to %s (offset %fs)", buf, d);
+}

src/usr.sbin/ntpd/ntpd.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.h,v 1.37 2004/09/18 07:33:14 henning Exp $ */
+/*	$OpenBSD: ntpd.h,v 1.38 2004/09/18 20:01:38 henning Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -109,8 +109,9 @@ struct ntp_peer {
 struct ntpd_conf {
 	TAILQ_HEAD(listen_addrs, listen_addr)	listen_addrs;
 	TAILQ_HEAD(ntp_peers, ntp_peer)		ntp_peers;
-	u_int8_t				opts;
 	u_int8_t				listen_all;
+	u_int8_t				settime;
+	u_int8_t				debug;
 	struct ntp_status			status;
 };
 
@@ -149,6 +150,7 @@ struct imsgbuf {
 enum imsg_type {
 	IMSG_NONE,
 	IMSG_ADJTIME,
+	IMSG_SETTIME,
 	IMSG_HOST_DNS
 };
 
@@ -200,6 +202,7 @@ void	 imsg_free(struct imsg *);
 /* ntp.c */
 pid_t	 ntp_main(int[2], struct ntpd_conf *);
 void	 ntp_adjtime(void);
+void	 ntp_settime(double);
 void	 ntp_host_dns(char *, u_int32_t);
 
 /* parse.y */
@@ -224,7 +227,7 @@ int	client_peer_init(struct ntp_peer *);
 int	client_addr_init(struct ntp_peer *);
 int	client_nextaddr(struct ntp_peer *);
 int	client_query(struct ntp_peer *);
-int	client_dispatch(struct ntp_peer *);
+int	client_dispatch(struct ntp_peer *, u_int8_t);
 
 /* util.c */
 double			gettime(void);