provide most of the client functionality.

hook the descriptors into the main poll and such.
we're not doing anything with the reply we recive yet, tho.
mostly hacked on the Frankfurt->Montreal flight, as batteries and those
horrible air canada seats permitted...

src/usr.sbin/ntpd/Makefile

@@ -1,10 +1,10 @@
-#	$OpenBSD: Makefile,v 1.4 2004/06/02 10:08:59 henning Exp $
+#	$OpenBSD: Makefile,v 1.5 2004/06/17 19:17:48 henning Exp $
 
 .PATH:		${.CURDIR}/..
 
 PROG=	ntpd
 SRCS=	ntpd.c buffer.c log.c imsg.c ntp.c ntp_msg.c parse.y config.c \
-	server.c
+	server.c client.c
 CFLAGS+= -Wall -I${.CURDIR}
 CFLAGS+= -Wstrict-prototypes -Wmissing-prototypes
 CFLAGS+= -Wmissing-declarations

src/usr.sbin/ntpd/client.c

@@ -0,0 +1,129 @@
+/*	$OpenBSD: client.c,v 1.1 2004/06/17 19:17:48 henning Exp $ */
+
+/*
+ * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
+ * Copyright (c) 2004 Alexander Guy <alexander.guy@andern.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "ntpd.h"
+
+int
+client_peer_init(struct ntp_peer *p)
+{
+	struct sockaddr_in	*sa_in;
+	struct sockaddr_in6	*sa_in6;
+
+	if ((p->query = calloc(1, sizeof(struct ntp_msg))) == NULL)
+		fatal("client_query calloc");
+
+	switch (p->ss.ss_family) {
+	case AF_INET:
+		sa_in = (struct sockaddr_in *)&p->ss;
+		if (ntohs(sa_in->sin_port) == 0)
+			sa_in->sin_port = htons(123);
+		break;
+	case AF_INET6:
+		sa_in6 = (struct sockaddr_in6 *)&p->ss;
+		if (ntohs(sa_in6->sin6_port) == 0)
+			sa_in6->sin6_port = htons(123);
+		break;
+	default:
+		fatal("king bula sez: wrong AF in client_peer_init");
+		/* not reached */
+	}
+
+	if ((p->query->fd = socket(p->ss.ss_family, SOCK_DGRAM, 0)) == -1)
+		fatal("client_query socket");
+
+	p->query->msg.status = MODE_CLIENT | (NTP_VERSION << 3);
+	p->state = STATE_NONE;
+	p->next = time(NULL);
+
+	return (0);
+}
+
+int
+client_query(struct ntp_peer *p)
+{
+	/*
+	 * Send out a random 64-bit number as our transmit time.  The NTP
+	 * server will copy said number into the originate field on the
+	 * response that it sends us.  This is totally legal per the SNTP spec.
+	 *
+	 * The impact of this is two fold: we no longer send out the current
+	 * system time for the world to see (which may aid an attacker), and
+	 * it gives us a (not very secure) way of knowing that we're not
+	 * getting spoofed by an attacker that can't capture our traffic
+	 * but can spoof packets from the NTP server we're communicating with.
+	 *
+	 * Save the real transmit timestamp locally.
+	 */
+
+	p->query->msg.xmttime.int_part = arc4random();
+	p->query->msg.xmttime.fraction = arc4random();
+	get_ts(&p->query->xmttime);
+
+	ntp_sendmsg(p->query->fd, (struct sockaddr *)&p->ss, &p->query->msg,
+	    NTP_MSGSIZE_NOAUTH, 0);
+	p->state = STATE_QUERY_SENT;
+	p->next = 0;
+	p->deadline = time(NULL) + MAX_QUERYTIME;
+
+	return (0);
+}
+
+int
+client_dispatch(struct ntp_peer *p)
+{
+	struct sockaddr_storage	 fsa;
+	socklen_t		 fsa_len;
+	char			 buf[NTP_MSGSIZE];
+	ssize_t			 size;
+	struct ntp_msg		 msg;
+	struct l_fixedpt	 rtt, t;
+
+	fsa_len = sizeof(fsa);
+	if ((size = recvfrom(p->query->fd, &buf, sizeof(buf), 0,
+	    (struct sockaddr *)&fsa, &fsa_len)) == -1)
+		fatal("recvfrom");
+
+	ntp_getmsg(buf, size, &msg);
+
+	if (msg.orgtime.int_part != p->query->msg.xmttime.int_part ||
+	    msg.orgtime.fraction != p->query->msg.xmttime.fraction) {
+		log_warn("received packet without correct cookie, discarding");
+		return (0);
+	}
+
+log_debug("reply received");
+
+	/* XXX parse */
+	get_ts(&t);
+	rtt.int_part = (t.int_part - p->query->xmttime.int_part) -
+	    (msg.rectime.int_part - msg.xmttime.int_part);
+
+	p->state = STATE_REPLY_RECEIVED;
+	p->next = time(NULL) + QUERY_INTERVAL;
+	p->deadline = 0;
+
+	return (0);
+}

src/usr.sbin/ntpd/ntp.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntp.c,v 1.6 2004/06/02 10:08:59 henning Exp $ */
+/*	$OpenBSD: ntp.c,v 1.7 2004/06/17 19:17:48 henning Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -52,12 +52,15 @@ ntp_sighdlr(int sig)
 pid_t
 ntp_main(int pipe_prnt[2], struct ntpd_conf *conf)
 {
-	int			 nfds, i, j;
+	int			 nfds, i, j, idx_peers, timeout;
 	pid_t			 pid;
 	struct pollfd		 pfd[OPEN_MAX];
 	struct passwd		*pw;
 	struct servent		*se;
 	struct listen_addr	*la;
+	struct ntp_peer		*p;
+	struct ntp_peer		*idx2peer[OPEN_MAX];
+	time_t			 nextaction;
 
 	switch (pid = fork()) {
 	case -1:
@@ -98,10 +101,15 @@ ntp_main(int pipe_prnt[2], struct ntpd_conf *conf)
 	close(pipe_prnt[0]);
 	imsg_init(&ibuf_main, pipe_prnt[1]);
 
+	TAILQ_FOREACH(p, &conf->ntp_peers, entry)
+		client_peer_init(p);
+
 	log_info("ntp engine ready");
 
 	while (ntp_quit == 0) {
 		bzero(&pfd, sizeof(pfd));
+		bzero(idx2peer, sizeof(idx2peer));
+		nextaction = time(NULL) + 240;
 		pfd[PFD_PIPE_MAIN].fd = ibuf_main.fd;
 		pfd[PFD_PIPE_MAIN].events = POLLIN;
 		if (ibuf_main.w.queued > 0)
@@ -112,14 +120,38 @@ ntp_main(int pipe_prnt[2], struct ntpd_conf *conf)
 			pfd[i].fd = la->fd;
 			pfd[i].events = POLLIN;
 			i++;
+			if (i > OPEN_MAX)
+				fatal("i > OPEN_MAX");
+		}
+
+
+		idx_peers = i;
+		TAILQ_FOREACH(p, &conf->ntp_peers, entry) {
+			if (p->next > 0 && p->next < nextaction)
+				nextaction = p->next;
+			if ((p->next > 0 && p->next <= time(NULL)) ||
+			    (p->deadline > 0 && p->deadline <= time(NULL)))
+				client_query(p);
+
+			if (p->state == STATE_QUERY_SENT) {
+				pfd[i].fd = p->query->fd;
+				pfd[i].events = POLLIN;
+				idx2peer[i - idx_peers] = p;
+				i++;
+				if (i > OPEN_MAX)
+					fatal("i > OPEN_MAX");
+			}
 		}
 
-		if ((nfds = poll(pfd, i, INFTIM)) == -1)
+		timeout = nextaction - time(NULL);
+		if (timeout < 0)
+			timeout = 0;
+
+		if ((nfds = poll(pfd, i, timeout * 1000)) == -1)
 			if (errno != EINTR) {
 				log_warn("poll error");
 				ntp_quit = 1;
 			}
-
 		if (nfds > 0 && (pfd[PFD_PIPE_MAIN].revents & POLLOUT))
 			if (msgbuf_write(&ibuf_main.w) < 0) {
 				log_warn("pipe write error (to parent)");
@@ -132,12 +164,20 @@ ntp_main(int pipe_prnt[2], struct ntpd_conf *conf)
 				ntp_quit = 1;
 		}
 
-		for (j = 1; nfds > 0 && j < i; j++)
+		for (j = 1; nfds > 0 && j < idx_peers; j++)
 			if (pfd[j].revents & POLLIN) {
 				nfds--;
 				if (ntp_dispatch(pfd[j].fd) == -1)
 					ntp_quit = 1;
 			}
+
+		for (; nfds > 0 && j < i; j++)
+			if (pfd[j].revents & POLLIN) {
+				nfds--;
+				if (client_dispatch(idx2peer[j - idx_peers]) ==
+				     -1)
+					ntp_quit = 1;
+			}
 	}
 
 	msgbuf_write(&ibuf_main.w);

src/usr.sbin/ntpd/ntp.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntp.h,v 1.4 2004/06/05 12:29:15 alexander Exp $ */
+/*	$OpenBSD: ntp.h,v 1.5 2004/06/17 19:17:48 henning Exp $ */
 
 /*
  * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
@@ -109,6 +109,12 @@ struct ntp_msg {
 	u_int8_t digest[NTP_DIGESTSIZE];
 };
 
+struct ntp_query {
+	int			fd;
+	struct ntp_msg		msg;
+	struct l_fixedpt	xmttime;
+};
+
 /*
  *	Leap Second Codes (high order two bits)
  */
@@ -138,4 +144,8 @@ struct ntp_msg {
 
 #define	JAN_1970	2208988800UL	/* 1970 - 1900 in seconds */
 
-#endif /* _NTP_H_ */
+#define	NTP_VERSION	4
+#define	MAX_QUERYTIME	30	/* max seconds a single query might take */
+#define	QUERY_INTERVAL	60	/* sync with peers every n seconds */
+
+#endif	/* _NTP_H_ */

src/usr.sbin/ntpd/ntpd.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.c,v 1.4 2004/06/01 21:58:08 henning Exp $ */
+/*	$OpenBSD: ntpd.c,v 1.5 2004/06/17 19:17:48 henning Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -91,6 +91,7 @@ main(int argc, char *argv[])
 
 	bzero(&conf, sizeof(conf));
 	TAILQ_INIT(&conf.listen_addrs);
+	TAILQ_INIT(&conf.ntp_peers);
 
 	log_init(1);		/* log to stderr until daemonized */
 

src/usr.sbin/ntpd/ntpd.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.h,v 1.5 2004/06/05 12:29:15 alexander Exp $ */
+/*	$OpenBSD: ntpd.h,v 1.6 2004/06/17 19:17:48 henning Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -34,14 +34,30 @@
 #define	NTPD_OPT_VERBOSE		0x0001
 #define	NTPD_OPT_VERBOSE2		0x0002
 
+enum client_state {
+	STATE_NONE,
+	STATE_QUERY_SENT,
+	STATE_REPLY_RECEIVED
+};
+
 struct listen_addr {
 	TAILQ_ENTRY(listen_addr)	 entry;
 	struct sockaddr_storage		 sa;
 	int				 fd;
 };
 
+struct ntp_peer {
+	TAILQ_ENTRY(ntp_peer)		 entry;
+	struct sockaddr_storage		 ss;
+	struct ntp_query		*query;
+	enum client_state		 state;
+	time_t				 next;
+	time_t				 deadline;
+};
+
 struct ntpd_conf {
 	TAILQ_HEAD(listen_addrs, listen_addr)	listen_addrs;
+	TAILQ_HEAD(ntp_peers, ntp_peer)		ntp_peers;
 	u_int8_t				opts;
 };
 
@@ -103,6 +119,7 @@ void		 log_info(const char *, ...);
 void		 log_debug(const char *, ...);
 void		 fatal(const char *);
 void		 fatalx(const char *);
+const char *	 log_sockaddr(struct sockaddr *);
 
 /* buffer.c */
 struct buf	*buf_open(ssize_t);
@@ -144,3 +161,8 @@ int	ntp_sendmsg(int, struct sockaddr *, struct ntp_msg *, ssize_t, int);
 /* server.c */
 int	setup_listeners(struct servent *, struct ntpd_conf *);
 int	ntp_reply(int, struct sockaddr *, struct ntp_msg *, int);
+
+/* client.c */
+int	client_peer_init(struct ntp_peer *);
+int	client_query(struct ntp_peer *);
+int	client_dispatch(struct ntp_peer *);

src/usr.sbin/ntpd/parse.y

@@ -1,4 +1,4 @@
-/*	$OpenBSD: parse.y,v 1.1 2004/06/01 21:58:09 henning Exp $ */
+/*	$OpenBSD: parse.y,v 1.2 2004/06/17 19:17:48 henning Exp $ */
 
 /*
  * Copyright (c) 2002, 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -77,6 +77,7 @@ typedef struct {
 %}
 
 %token	LISTEN ON
+%token	SERVER
 %token	ERROR
 %token	<v.string>		STRING
 %type	<v.number>		number
@@ -130,9 +131,23 @@ conf_main	:  LISTEN ON address	{
 			    NULL)
 				fatal("parse conf_main listen on calloc");
 
+			la->fd = -1;
 			memcpy(&la->sa, &$3, sizeof(struct sockaddr_storage));
 			TAILQ_INSERT_TAIL(&conf->listen_addrs, la, entry);
 		}
+		| SERVER address	{
+			struct ntp_peer		*p;
+
+			if (!TAILQ_EMPTY(&conf->ntp_peers)) {
+				yyerror("king bula sez: only on remote server "
+				    "supported for now");
+				YYERROR;
+			}
+			if ((p = calloc(1, sizeof(struct listen_addr))) == NULL)
+				fatal("parse conf_mail server on calloc");
+			memcpy(&p->ss, &$2, sizeof(struct sockaddr_storage));
+			TAILQ_INSERT_TAIL(&conf->ntp_peers, p, entry);
+		}
 		;
 
 address		: STRING		{
@@ -192,7 +207,8 @@ lookup(char *s)
 	/* this has to be sorted always */
 	static const struct keywords keywords[] = {
 		{ "listen",		LISTEN},
-		{ "on",			ON}
+		{ "on",			ON},
+		{ "server",		SERVER}
 	};
 	const struct keywords	*p;
 
@@ -402,12 +418,14 @@ parse_config(char *filename, struct ntpd_conf *xconf)
 {
 	struct sym		*sym, *next;
 	struct listen_addr	*la;
+	struct ntp_peer		*p;
 
 	if ((conf = calloc(1, sizeof(struct ntpd_conf))) == NULL)
 		fatal(NULL);
 	lineno = 1;
 	errors = 0;
 	TAILQ_INIT(&conf->listen_addrs);
+	TAILQ_INIT(&conf->ntp_peers);
 
 	if ((fin = fopen(filename, "r")) == NULL) {
 		log_warn("%s", filename);
@@ -444,6 +462,16 @@ parse_config(char *filename, struct ntpd_conf *xconf)
 		TAILQ_INSERT_TAIL(&xconf->listen_addrs, la, entry);
 	}
 
+	while ((p = TAILQ_FIRST(&xconf->ntp_peers)) != NULL) {
+		TAILQ_REMOVE(&xconf->ntp_peers, p, entry);
+		free(p);
+	}
+
+	while ((p = TAILQ_FIRST(&conf->ntp_peers)) != NULL) {
+		TAILQ_REMOVE(&conf->ntp_peers, p, entry);
+		TAILQ_INSERT_TAIL(&xconf->ntp_peers, p, entry);
+	}
+
 	free(conf);
 
 	return (errors ? -1 : 0);