Use effective_proposal data to build resolv.conf contents.

Fix a missing != NULL, and add a comment on why no search
path and no dns servers means resolv.conf.tail is ignored.

3 files changed, 42 insertions, 48 deletions

diff --git a/sbin/dhclient/dhclient.c b/sbin/dhclient/dhclient.c
index 1f67531e9cf..eb394d5b590 100644
--- a/sbin/dhclient/dhclient.c
+++ b/sbin/dhclient/dhclient.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dhclient.c,v 1.488 2017/07/30 14:05:41 krw Exp $	*/
+/*	$OpenBSD: dhclient.c,v 1.489 2017/07/30 15:26:46 krw Exp $	*/
 
 /*
  * Copyright 2004 Henning Brauer <henning@openbsd.org>
@@ -982,7 +982,6 @@ dhcpnak(struct interface_info *ifi, struct option_data *options, char *info)
 void
 bind_lease(struct interface_info *ifi)
 {
-	struct option_data	*options;
 	struct client_lease	*lease, *pl;
 	struct proposal		*active_proposal = NULL;
 	struct proposal		*offered_proposal = NULL;
@@ -998,7 +997,6 @@ bind_lease(struct interface_info *ifi)
 	ifi->offer->resolv_conf = NULL;
 
 	lease = apply_defaults(ifi->offer);
-	options = lease->options;
 
 	set_lease_times(lease);
 
@@ -1023,15 +1021,17 @@ bind_lease(struct interface_info *ifi)
 		}
 	}
 
-	ifi->offer->resolv_conf = resolv_conf_contents(ifi->name,
-	    &options[DHO_DOMAIN_NAME], &options[DHO_DOMAIN_NAME_SERVERS],
-	    &options[DHO_DOMAIN_SEARCH]);
-
 	/* Replace the old active lease with the accepted offer. */
 	ifi->active = ifi->offer;
 	ifi->offer = NULL;
 	effective_proposal = lease_as_proposal(lease);
 
+	ifi->active->resolv_conf = resolv_conf_contents(ifi->name,
+	    effective_proposal->rtsearch,
+	    effective_proposal->rtsearch_len,
+	    effective_proposal->rtdns,
+	    effective_proposal->rtdns_len);
+
 	set_mtu(effective_proposal->inits, effective_proposal->mtu);
 
 	set_address(ifi->name, effective_proposal->ifa,
@@ -1887,8 +1887,8 @@ lease_as_proposal(struct client_lease *lease)
 			servers = MAXNS;
 		if (servers > 0) {
 			proposal->addrs |= RTA_DNS;
-			proposal->rtdns_len = opt->len;
-			memcpy(proposal->rtdns, opt->data, opt->len);
+			proposal->rtdns_len = servers * sizeof(struct in_addr);
+			memcpy(proposal->rtdns, opt->data, proposal->rtdns_len);
 		}
 	}
 
diff --git a/sbin/dhclient/kroute.c b/sbin/dhclient/kroute.c
index a042b9661cf..704af6f88f8 100644
--- a/sbin/dhclient/kroute.c
+++ b/sbin/dhclient/kroute.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kroute.c,v 1.123 2017/07/30 14:05:41 krw Exp $	*/
+/*	$OpenBSD: kroute.c,v 1.124 2017/07/30 15:26:46 krw Exp $	*/
 
 /*
  * Copyright 2012 Kenneth R Westerback <krw@openbsd.org>
@@ -820,56 +820,50 @@ done:
  */
 char *
 resolv_conf_contents(char *name,
-    struct option_data *domainname, struct option_data *nameservers,
-    struct option_data *domainsearch)
+    uint8_t *rtsearch, unsigned int rtsearch_len,
+    uint8_t *rtdns, unsigned int rtdns_len)
 {
-	char		*dn, *ns, *nss[MAXNS], *contents, *courtesy, *p, *buf;
+	char		*dn, *nss[MAXNS], *contents, *courtesy;
+	struct in_addr	*addr;
 	size_t		 len;
-	int		 i, rslt;
+	unsigned int	 i, servers;
+	int		 rslt;
 
 	memset(nss, 0, sizeof(nss));
+	len = 0;
 
-	if (domainsearch->len != 0) {
-		buf = pretty_print_domain_search(domainsearch->data,
-		    domainsearch->len);
-		if (buf == NULL)
-			dn = strdup("");
-		else {
-			rslt = asprintf(&dn, "search %s\n", buf);
-			if (rslt == -1)
-				dn = NULL;
-		}
-	} else if (domainname->len != 0) {
-		rslt = asprintf(&dn, "search %s\n",
-		    pretty_print_option(DHO_DOMAIN_NAME, domainname, 0));
+	if (rtsearch_len != 0) {
+		rslt = asprintf(&dn, "search %.*s\n", rtsearch_len,
+		    rtsearch);
 		if (rslt == -1)
 			dn = NULL;
 	} else
 		dn = strdup("");
 	if (dn == NULL)
 		fatalx("no memory for domainname");
-
-	if (nameservers->len != 0) {
-		ns = pretty_print_option(DHO_DOMAIN_NAME_SERVERS, nameservers,
-		    0);
-		for (i = 0; i < MAXNS; i++) {
-			p = strsep(&ns, " ");
-			if (p == NULL)
-				break;
-			if (*p == '\0')
-				continue;
-			rslt = asprintf(&nss[i], "nameserver %s\n", p);
+	len += strlen(dn);
+
+	if (rtdns_len != 0) {
+		addr = (struct in_addr *)rtdns;
+		servers = rtdns_len / sizeof(struct in_addr);
+		if (servers > MAXNS)
+			servers = MAXNS;
+		for (i = 0; i < servers; i++) {
+			rslt = asprintf(&nss[i], "nameserver %s\n",
+			    inet_ntoa(*addr));
 			if (rslt == -1)
 				fatalx("no memory for nameserver");
+			len += strlen(nss[i]);
+			addr++;
 		}
 	}
 
-	len = strlen(dn);
-	for (i = 0; i < MAXNS; i++)
-		if (nss[i] != NULL)
-			len += strlen(nss[i]);
-
-	if (len > 0 && config->resolv_tail)
+	/*
+	 * XXX historically dhclient-script did not overwrite
+	 *     resolv.conf when neither search nor dns info
+	 *     was provided. Is that really what we want?
+	 */
+	if (len > 0 && config->resolv_tail != NULL)
 		len += strlen(config->resolv_tail);
 
 	if (len == 0) {
@@ -900,7 +894,7 @@ resolv_conf_contents(char *name,
 		}
 	}
 
-	if (config->resolv_tail)
+	if (config->resolv_tail != NULL)
 		strlcat(contents, config->resolv_tail, len);
 
 	return contents;
diff --git a/sbin/dhclient/privsep.h b/sbin/dhclient/privsep.h
index 07ada0d8262..63d88148dd2 100644
--- a/sbin/dhclient/privsep.h
+++ b/sbin/dhclient/privsep.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: privsep.h,v 1.49 2017/07/27 12:45:06 krw Exp $ */
+/*	$OpenBSD: privsep.h,v 1.50 2017/07/30 15:26:46 krw Exp $ */
 
 /*
  * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
@@ -54,8 +54,8 @@ int	dispatch_imsg(char *, int, int, int, struct imsgbuf *);
 void	priv_add_route(int, int, struct imsg_add_route *);
 void	priv_flush_routes(char *, int, int);
 
-char	*resolv_conf_contents(char *, struct option_data *,
-    struct option_data *, struct option_data *);
+char	*resolv_conf_contents(char *, uint8_t *, unsigned int, uint8_t *,
+    unsigned int);
 int	resolv_conf_priority(int, int);
 void	priv_write_resolv_conf(uint8_t *, size_t);