Use ntpd's deferred DNS resolving for constraints as well. This

allows to get constraint addresses even if network/DNS is not
available at startup (or system boot).
thumbs up & OK henning@

src/usr.sbin/ntpd/client.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: client.c,v 1.99 2015/02/10 06:40:08 reyk Exp $ */
+/*	$OpenBSD: client.c,v 1.100 2015/02/12 01:54:57 reyk Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -107,7 +107,7 @@ client_nextaddr(struct ntp_peer *p)
 		return (-1);
 
 	if (p->addr_head.a == NULL) {
-		priv_host_dns(p->addr_head.name, p->id);
+		priv_dns(IMSG_HOST_DNS, p->addr_head.name, p->id);
 		p->state = STATE_DNS_INPROGRESS;
 		return (-1);
 	}

src/usr.sbin/ntpd/constraint.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: constraint.c,v 1.3 2015/02/10 23:52:41 reyk Exp $	*/
+/*	$OpenBSD: constraint.c,v 1.4 2015/02/12 01:54:57 reyk Exp $	*/
 
 /*
  * Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
@@ -43,6 +43,8 @@
 #include "ntpd.h"
 
 int	 constraint_addr_init(struct constraint *);
+struct constraint *
+	 constraint_byid(u_int32_t);
 struct constraint *
 	 constraint_byfd(int);
 struct constraint *
@@ -51,6 +53,8 @@ int	 constraint_close(int);
 void	 constraint_update(void);
 void	 constraint_reset(void);
 int	 constraint_cmp(const void *, const void *);
+void	 constraint_add(struct constraint *);
+void	 constraint_remove(struct constraint *);
 
 struct httpsdate *
 	 httpsdate_init(const char *, const char *, const char *,
@@ -63,6 +67,8 @@ void	*httpsdate_query(const char *, const char *, const char *,
 
 char	*tls_readline(struct tls *, size_t *, size_t *, struct timeval *);
 
+extern u_int constraint_cnt;
+
 struct httpsdate {
 	char			*tls_host;
 	char			*tls_port;
@@ -91,31 +97,37 @@ constraint_addr_init(struct constraint *cstr)
 	struct sockaddr_in	*sa_in;
 	struct sockaddr_in6	*sa_in6;
 	struct ntp_addr		*h;
-	int			 cnt = 0;
-
-	for (h = cstr->addr; h != NULL; h = h->next) {
-		switch (h->ss.ss_family) {
-		case AF_INET:
-			sa_in = (struct sockaddr_in *)&h->ss;
-			if (ntohs(sa_in->sin_port) == 0)
-				sa_in->sin_port = htons(443);
-			cstr->state = STATE_DNS_DONE;
-			break;
-		case AF_INET6:
-			sa_in6 = (struct sockaddr_in6 *)&h->ss;
-			if (ntohs(sa_in6->sin6_port) == 0)
-				sa_in6->sin6_port = htons(443);
-			cstr->state = STATE_DNS_DONE;
-			break;
-		default:
-			/* XXX king bula sez it? */
-			fatalx("wrong AF in constraint_addr_init");
-			/* NOTREACHED */
-		}
-		cnt++;
+
+	if (cstr->state == STATE_DNS_INPROGRESS)
+		return (0);
+
+	if (cstr->addr_head.a == NULL) {
+		priv_dns(IMSG_CONSTRAINT_DNS, cstr->addr_head.name, cstr->id);
+		cstr->state = STATE_DNS_INPROGRESS;
+		return (0);
+	}
+
+	h = cstr->addr;
+	switch (h->ss.ss_family) {
+	case AF_INET:
+		sa_in = (struct sockaddr_in *)&h->ss;
+		if (ntohs(sa_in->sin_port) == 0)
+			sa_in->sin_port = htons(443);
+		cstr->state = STATE_DNS_DONE;
+		break;
+	case AF_INET6:
+		sa_in6 = (struct sockaddr_in6 *)&h->ss;
+		if (ntohs(sa_in6->sin6_port) == 0)
+			sa_in6->sin6_port = htons(443);
+		cstr->state = STATE_DNS_DONE;
+		break;
+	default:
+		/* XXX king bula sez it? */
+		fatalx("wrong AF in constraint_addr_init");
+		/* NOTREACHED */
 	}
 
-	return (cnt);
+	return (1);
 }
 
 int
@@ -134,6 +146,10 @@ constraint_query(struct constraint *cstr)
 	case STATE_DNS_DONE:
 		/* Proceed and query the time */
 		break;
+	case STATE_DNS_TEMPFAIL:
+		/* Retry resolving the address */
+		constraint_init(cstr);		
+		return (-1);
 	case STATE_QUERY_SENT:
 		if (cstr->last + CONSTRAINT_SCAN_TIMEOUT > now) {
 			/* The caller should expect a reply */
@@ -277,6 +293,19 @@ constraint_check_child(void)
 	} while (pid > 0 || (pid == -1 && errno == EINTR));
 }
 
+struct constraint *
+constraint_byid(u_int32_t id)
+{
+	struct constraint	*cstr;
+
+	TAILQ_FOREACH(cstr, &conf->constraints, entry) {
+		if (cstr->id == id)
+			return (cstr);
+	}
+
+	return (NULL);
+}
+
 struct constraint *
 constraint_byfd(int fd)
 {
@@ -326,6 +355,23 @@ constraint_close(int fd)
 	return (1);
 }
 
+void
+constraint_add(struct constraint *cstr)
+{
+	TAILQ_INSERT_TAIL(&conf->constraints, cstr, entry);
+	constraint_cnt += constraint_init(cstr);
+}
+
+void
+constraint_remove(struct constraint *cstr)
+{
+	TAILQ_REMOVE(&conf->constraints, cstr, entry);
+	free(cstr->addr_head.name);
+	free(cstr->addr_head.path);
+	free(cstr);
+	constraint_cnt--;
+}
+
 int
 constraint_dispatch_msg(struct pollfd *pfd)
 {
@@ -383,6 +429,54 @@ constraint_dispatch_msg(struct pollfd *pfd)
 	return (0);
 }
 
+void
+constraint_dns(u_int32_t id, u_int8_t *data, size_t len)
+{
+	struct constraint	*cstr, *ncstr;
+	u_int8_t		*p;
+	struct ntp_addr		*h;
+
+	if ((cstr = constraint_byid(id)) == NULL) {
+		log_warnx("IMSG_CONSTRAINT_DNS with invalid constraint id");
+		return;
+	}
+	if (cstr->addr != NULL) {
+		log_warnx("IMSG_CONSTRAINT_DNS but addr != NULL!");
+		return;
+	}
+	if (len == 0) {
+		log_debug("%s FAILED", __func__);
+		cstr->state = STATE_DNS_TEMPFAIL;
+		return;
+	}
+
+	if ((len % sizeof(struct sockaddr_storage)) != 0)
+		fatalx("IMSG_CONSTRAINT_DNS len");
+
+	p = data;
+	do {
+		if ((h = calloc(1, sizeof(*h))) == NULL)
+			fatal("calloc ntp_addr");
+		memcpy(&h->ss, p, sizeof(h->ss));
+		p += sizeof(h->ss);
+		len -= sizeof(h->ss);
+
+		ncstr = new_constraint();
+		ncstr->addr = h;
+		ncstr->addr_head.a = h;
+		ncstr->addr_head.name = strdup(cstr->addr_head.name);
+		ncstr->addr_head.path = strdup(cstr->addr_head.path);
+		if (ncstr->addr_head.name == NULL ||
+		    ncstr->addr_head.path == NULL)
+			fatal("calloc name");
+		ncstr->addr_head.pool = cstr->addr_head.pool;
+
+		constraint_add(ncstr);
+	} while (len && cstr->addr_head.pool);
+
+	constraint_remove(cstr);
+}
+
 int
 constraint_cmp(const void *a, const void *b)
 {

src/usr.sbin/ntpd/ntp.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntp.c,v 1.128 2015/02/10 06:40:08 reyk Exp $ */
+/*	$OpenBSD: ntp.c,v 1.129 2015/02/12 01:54:57 reyk Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -49,6 +49,7 @@ struct ntpd_conf	*conf;
 struct ctl_conns	 ctl_conns;
 u_int			 peer_cnt;
 u_int			 sensors_cnt;
+u_int			 constraint_cnt;
 time_t			 lastreport;
 
 void	ntp_sighdlr(int);
@@ -84,7 +85,7 @@ ntp_main(int pipe_prnt[2], int fd_ctl, struct ntpd_conf *nconf,
 	int			 ctls, boundaries;
 	u_int			 pfd_elms = 0, idx2peer_elms = 0;
 	u_int			 listener_cnt, new_cnt, sent_cnt, trial_cnt;
-	u_int			 ctl_cnt, constraint_cnt;
+	u_int			 ctl_cnt;
 	pid_t			 pid;
 	struct pollfd		*pfd = NULL;
 	struct servent		*se;
@@ -582,6 +583,10 @@ ntp_dispatch_imsg_dns(void)
 			else
 				client_addr_init(peer);
 			break;
+		case IMSG_CONSTRAINT_DNS:
+			constraint_dns(imsg.hdr.peerid,
+			    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
+			break;
 		default:
 			break;
 		}
@@ -762,12 +767,12 @@ priv_settime(double offset)
 }
 
 void
-priv_host_dns(char *name, u_int32_t peerid)
+priv_dns(int cmd, char *name, u_int32_t peerid)
 {
 	u_int16_t	dlen;
 
 	dlen = strlen(name) + 1;
-	imsg_compose(ibuf_dns, IMSG_HOST_DNS, peerid, 0, -1, name, dlen);
+	imsg_compose(ibuf_dns, cmd, peerid, 0, -1, name, dlen);
 }
 
 void

src/usr.sbin/ntpd/ntp_dns.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntp_dns.c,v 1.8 2015/01/21 03:14:10 bcook Exp $ */
+/*	$OpenBSD: ntp_dns.c,v 1.9 2015/02/12 01:54:57 reyk Exp $ */
 
 /*
  * Copyright (c) 2003-2008 Henning Brauer <henning@openbsd.org>
@@ -129,6 +129,7 @@ dns_dispatch_imsg(void)
 	char			*name;
 	struct ntp_addr		*h, *hn;
 	struct ibuf		*buf;
+	const char		*str;
 
 	if ((n = imsg_read(ibuf_dns)) == -1)
 		return (-1);
@@ -147,16 +148,21 @@ dns_dispatch_imsg(void)
 
 		switch (imsg.hdr.type) {
 		case IMSG_HOST_DNS:
+		case IMSG_CONSTRAINT_DNS:
+			if (imsg.hdr.type == IMSG_HOST_DNS)
+				str = "IMSG_HOST_DNS";
+			else
+				str = "IMSG_CONSTRAINT_DNS";
 			name = imsg.data;
 			if (imsg.hdr.len < 1 + IMSG_HEADER_SIZE)
-				fatalx("invalid IMSG_HOST_DNS received");
+				fatalx("invalid %s received", str);
 			imsg.hdr.len -= 1 + IMSG_HEADER_SIZE;
 			if (name[imsg.hdr.len] != '\0' ||
 			    strlen(name) != imsg.hdr.len)
-				fatalx("invalid IMSG_HOST_DNS received");
+				fatalx("invalid %s received", str);
 			if ((cnt = host_dns(name, &hn)) == -1)
 				break;
-			buf = imsg_create(ibuf_dns, IMSG_HOST_DNS,
+			buf = imsg_create(ibuf_dns, imsg.hdr.type,
 			    imsg.hdr.peerid, 0,
 			    cnt * sizeof(struct sockaddr_storage));
 			if (cnt > 0) {

src/usr.sbin/ntpd/ntpd.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.h,v 1.118 2015/02/10 06:40:08 reyk Exp $ */
+/*	$OpenBSD: ntpd.h,v 1.119 2015/02/12 01:54:57 reyk Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -280,6 +280,7 @@ enum imsg_type {
 	IMSG_SETTIME,
 	IMSG_HOST_DNS,
 	IMSG_CONSTRAINT,
+	IMSG_CONSTRAINT_DNS,
 	IMSG_CTL_SHOW_STATUS,
 	IMSG_CTL_SHOW_PEERS,
 	IMSG_CTL_SHOW_PEERS_END,
@@ -302,7 +303,7 @@ enum ctl_actions {
 pid_t	 ntp_main(int[2], int, struct ntpd_conf *, struct passwd *);
 int	 priv_adjtime(void);
 void	 priv_settime(double);
-void	 priv_host_dns(char *, u_int32_t);
+void	 priv_dns(int, char *, u_int32_t);
 int	 offset_compare(const void *, const void *);
 void	 update_scale(double);
 time_t	 scale_interval(time_t);
@@ -345,6 +346,7 @@ int	 constraint_query(struct constraint *);
 int	 constraint_dispatch_msg(struct pollfd *);
 void	 constraint_check_child(void);
 int	 constraint_check(double);
+void	 constraint_dns(u_int32_t, u_int8_t *, size_t);
 
 /* util.c */
 double			 gettime_corrected(void);

src/usr.sbin/ntpd/parse.y

@@ -1,4 +1,4 @@
-/*	$OpenBSD: parse.y,v 1.59 2015/02/10 11:46:39 reyk Exp $ */
+/*	$OpenBSD: parse.y,v 1.60 2015/02/12 01:54:57 reyk Exp $ */
 
 /*
  * Copyright (c) 2002, 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -251,11 +251,10 @@ main		: LISTEN ON address listen_opts	{
 		}
 		| CONSTRAINT FROM url		{
 			struct constraint	*p;
-			struct ntp_addr		*h, *next;
+			struct ntp_addr		*h;
 
 			p = new_constraint();
-			for (h = $3->a; h != NULL; h = next) {
-				next = h->next;
+			if ((h = $3->a) != NULL) {
 				if (h->ss.ss_family != AF_INET &&
 				    h->ss.ss_family != AF_INET6) {
 					yyerror("IPv4 or IPv6 address "
@@ -267,8 +266,8 @@ main		: LISTEN ON address listen_opts	{
 					free($3);
 					YYERROR;
 				}
-				h->next = p->addr;
 				p->addr = h;
+				host_dns_free(h->next);
 			}
 
 			p->addr_head.a = p->addr;
@@ -332,16 +331,6 @@ url		: STRING		{
 				if (($$->name = strdup(hname)) == NULL)
 					fatal("strdup");
 			}
-
-			if ($$->a == NULL &&
-			    (host_dns($$->name, &$$->a) == -1 ||
-			    $$->a == NULL)) {
-				yyerror("could not resolve \"%s\"", $$->name);
-				free($$->name);
-				free($$->path);
-				free($$);
-				YYERROR;
-			}
 		}
 		;