A step in solving the bootstrap problem in a dnssec environement.

If the time is wrong, we cannot validate dnssec, leading to failed
DNS lookups, so we cannot adjust or set the time.  Work around this
by repeating a failed DNS lookup with a lookup with the DC (check
disabled) bit set. ok florian@

src/usr.sbin/ntpd/config.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: config.c,v 1.29 2018/09/07 20:31:39 kn Exp $ */
+/*	$OpenBSD: config.c,v 1.30 2019/05/28 06:49:46 otto Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -25,11 +25,13 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
+#include <resolv.h>
 #include <unistd.h>
 
 #include "ntpd.h"
 
 struct ntp_addr	*host_ip(const char *);
+int		 host_dns1(const char *, struct ntp_addr **, int);
 
 static u_int32_t		 maxid = 0;
 static u_int32_t		 constraint_maxid = 0;
@@ -85,7 +87,7 @@ host_dns_free(struct ntp_addr *hn)
 }
 
 int
-host_dns(const char *s, struct ntp_addr **hn)
+host_dns1(const char *s, struct ntp_addr **hn, int notauth)
 {
 	struct addrinfo		 hints, *res0, *res;
 	int			 error, cnt = 0;
@@ -111,6 +113,7 @@ host_dns(const char *s, struct ntp_addr **hn)
 		if ((h = calloc(1, sizeof(*h))) == NULL)
 			fatal(NULL);
 		memcpy(&h->ss, res->ai_addr, res->ai_addrlen);
+		h->notauth = notauth;
 
 		h->next = hh;
 		hh = h;
@@ -122,6 +125,24 @@ host_dns(const char *s, struct ntp_addr **hn)
 	return (cnt);
 }
 
+int
+host_dns(const char *s, struct ntp_addr **hn)
+{
+	int error, save_opts;
+	
+	log_debug("trying to resolve %s", s);
+	error = host_dns1(s, hn, 0);
+	if (error <= 0) {
+		log_debug("no luck, trying to resolve %s without checking", s);
+		save_opts = _res.options;
+		_res.options |= RES_USE_CD;
+		error = host_dns1(s, hn, 1);
+		_res.options = save_opts;
+	}
+	log_debug("resolve %s done: %d", s, error);
+	return error;
+}
+
 struct ntp_peer *
 new_peer(void)
 {

src/usr.sbin/ntpd/constraint.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: constraint.c,v 1.42 2019/01/21 11:08:37 jsing Exp $	*/
+/*	$OpenBSD: constraint.c,v 1.43 2019/05/28 06:49:46 otto Exp $	*/
 
 /*
  * Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
@@ -723,7 +723,7 @@ constraint_msg_dns(u_int32_t id, u_int8_t *data, size_t len)
 		return;
 	}
 
-	if ((len % sizeof(struct sockaddr_storage)) != 0)
+	if (len % (sizeof(struct sockaddr_storage) + sizeof(int)) != 0)
 		fatalx("IMSG_CONSTRAINT_DNS len");
 
 	p = data;
@@ -733,6 +733,9 @@ constraint_msg_dns(u_int32_t id, u_int8_t *data, size_t len)
 		memcpy(&h->ss, p, sizeof(h->ss));
 		p += sizeof(h->ss);
 		len -= sizeof(h->ss);
+		memcpy(&h->notauth, p, sizeof(int));
+		p += sizeof(int);
+		len -= sizeof(int);
 
 		if (ncstr == NULL || cstr->addr_head.pool) {
 			ncstr = new_constraint();

src/usr.sbin/ntpd/control.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: control.c,v 1.14 2019/01/14 16:30:21 florian Exp $ */
+/*	$OpenBSD: control.c,v 1.15 2019/05/28 06:49:46 otto Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -339,13 +339,17 @@ build_show_peer(struct ctl_show_peer *cp, struct ntp_peer *p)
 {
 	const char	*a = "not resolved";
 	const char	*pool = "", *addr_head_name = "";
+	const char	*auth = "";
 	u_int8_t	 shift, best, validdelaycnt, jittercnt;
 	time_t		 now;
 
 	now = getmonotime();
 
-	if (p->addr)
+	if (p->addr) {
 		a = log_sockaddr((struct sockaddr *)&p->addr->ss);
+		if (p->addr->notauth)
+			auth = " (non-dnssec lookup)";
+	}
 	if (p->addr_head.pool)
 		pool = "from pool ";
 
@@ -353,7 +357,7 @@ build_show_peer(struct ctl_show_peer *cp, struct ntp_peer *p)
 		addr_head_name = p->addr_head.name;
 
 	snprintf(cp->peer_desc, sizeof(cp->peer_desc),
-	    "%s %s%s", a, pool, addr_head_name);
+	    "%s %s%s%s", a, pool, addr_head_name, auth);
 
 	validdelaycnt = best = 0;
 	cp->offset = cp->delay = 0.0;

src/usr.sbin/ntpd/ntp.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntp.c,v 1.149 2019/01/07 20:33:40 tedu Exp $ */
+/*	$OpenBSD: ntp.c,v 1.150 2019/05/28 06:49:46 otto Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -512,13 +512,17 @@ ntp_dispatch_imsg_dns(void)
 			}
 
 			p = (u_char *)imsg.data;
-			while (dlen >= sizeof(struct sockaddr_storage)) {
+			while (dlen >= sizeof(struct sockaddr_storage) +
+			    sizeof(int)) {
 				if ((h = calloc(1, sizeof(struct ntp_addr))) ==
 				    NULL)
 					fatal(NULL);
 				memcpy(&h->ss, p, sizeof(h->ss));
 				p += sizeof(h->ss);
 				dlen -= sizeof(h->ss);
+				memcpy(&h->notauth, p, sizeof(int));
+				p += sizeof(int);
+				dlen -= sizeof(int);
 				if (peer->addr_head.pool) {
 					npeer = new_peer();
 					npeer->weight = peer->weight;

src/usr.sbin/ntpd/ntp_dns.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntp_dns.c,v 1.20 2017/04/17 16:03:15 otto Exp $ */
+/*	$OpenBSD: ntp_dns.c,v 1.21 2019/05/28 06:49:46 otto Exp $ */
 
 /*
  * Copyright (c) 2003-2008 Henning Brauer <henning@openbsd.org>
@@ -20,6 +20,8 @@
 #include <sys/resource.h>
 #include <sys/time.h>
 
+#include <netinet/in.h>
+
 #include <err.h>
 #include <errno.h>
 #include <poll.h>
@@ -28,6 +30,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <syslog.h>
+#include <resolv.h>
 #include <unistd.h>
 
 #include "ntpd.h"
@@ -55,6 +58,7 @@ ntp_dns(struct ntpd_conf *nconf, struct passwd *pw)
 	struct pollfd		 pfd[1];
 	int			 nfds, nullfd;
 
+	res_init();
 	if (setpriority(PRIO_PROCESS, 0, 0) == -1)
 		log_warn("could not set priority");
 
@@ -164,15 +168,21 @@ dns_dispatch_imsg(void)
 				break;
 			buf = imsg_create(ibuf_dns, imsg.hdr.type,
 			    imsg.hdr.peerid, 0,
-			    cnt * sizeof(struct sockaddr_storage));
+			    cnt * (sizeof(struct sockaddr_storage) + sizeof(int)));
 			if (cnt > 0) {
 				if (buf) {
-					for (h = hn; h != NULL; h = h->next)
+					for (h = hn; h != NULL; h = h->next) {
 						if (imsg_add(buf, &h->ss,
 						    sizeof(h->ss)) == -1) {
 							buf = NULL;
 							break;
 						}
+						if (imsg_add(buf, &h->notauth,
+						    sizeof(int)) == -1) {
+							buf = NULL;
+							break;
+						}
+					}
 				}
 				host_dns_free(hn);
 				hn = NULL;

src/usr.sbin/ntpd/ntpd.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.h,v 1.138 2019/01/14 16:30:21 florian Exp $ */
+/*	$OpenBSD: ntpd.h,v 1.139 2019/05/28 06:49:46 otto Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -108,6 +108,7 @@ struct listen_addr {
 struct ntp_addr {
 	struct ntp_addr		*next;
 	struct sockaddr_storage	 ss;
+	int			 notauth;
 };
 
 struct ntp_addr_wrap {