Take reyk's imsg resolv.conf improvements of a while ago to their

logical conclusion.

Nuke _PATH_RESOLV_CONF since the value is only meant to be
known inside priv_write_resolv_conf(). Just use a local const char *.

Bring priv_write_resolv_conf() into line with other priv_ functions
invoked from the dispatch loop. i.e. don't pass it the imsg, just pass
a pointer to the data and a size after ensuring there is data to pass.

4 files changed, 17 insertions, 23 deletions

diff --git a/sbin/dhclient/dhcpd.h b/sbin/dhclient/dhcpd.h
index 2e4d70f2a99..a3d279fe751 100644
--- a/sbin/dhclient/dhcpd.h
+++ b/sbin/dhclient/dhcpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dhcpd.h,v 1.191 2017/06/22 15:08:53 krw Exp $	*/
+/*	$OpenBSD: dhcpd.h,v 1.192 2017/06/23 15:40:56 krw Exp $	*/
 
 /*
  * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
@@ -157,7 +157,6 @@ struct interface_info {
 	TAILQ_HEAD(_leases, client_lease) leases;
 };
 
-#define	_PATH_RESOLV_CONF	"/etc/resolv.conf"
 #define	_PATH_DHCLIENT_CONF	"/etc/dhclient.conf"
 #define	_PATH_DHCLIENT_DB	"/var/db/dhclient.leases"
 
diff --git a/sbin/dhclient/kroute.c b/sbin/dhclient/kroute.c
index 5ac34c37880..878496f8293 100644
--- a/sbin/dhclient/kroute.c
+++ b/sbin/dhclient/kroute.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kroute.c,v 1.91 2017/04/12 12:22:25 krw Exp $	*/
+/*	$OpenBSD: kroute.c,v 1.92 2017/06/23 15:40:56 krw Exp $	*/
 
 /*
  * Copyright 2012 Kenneth R Westerback <krw@openbsd.org>
@@ -782,39 +782,29 @@ write_resolv_conf(u_int8_t *contents, size_t sz)
 }
 
 void
-priv_write_resolv_conf(struct interface_info *ifi, struct imsg *imsg)
+priv_write_resolv_conf(struct interface_info *ifi, u_int8_t *contents, size_t sz)
 {
-	u_int8_t *contents;
+	const char *path = "/etc/resolv.conf";
 	ssize_t n;
-	size_t sz;
 	int fd;
 
-
-	if (imsg->hdr.len < IMSG_HEADER_SIZE) {
-		log_warnx("short IMSG_WRITE_RESOLV_CONF");
-		return;
-	}
-
 	if (!resolv_conf_priority(ifi))
 		return;
 
-	contents = imsg->data;
-	sz = imsg->hdr.len - IMSG_HEADER_SIZE;
-
-	fd = open(_PATH_RESOLV_CONF, O_WRONLY | O_CREAT | O_TRUNC,
+	fd = open(path, O_WRONLY | O_CREAT | O_TRUNC,
 	    S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 
 	if (fd == -1) {
-		log_warn("Couldn't open '%s'", _PATH_RESOLV_CONF);
+		log_warn("Couldn't open '%s'", path);
 		return;
 	}
 
 	n = write(fd, contents, sz);
 	if (n == -1)
-		log_warn("Couldn't write contents to '%s'", _PATH_RESOLV_CONF);
+		log_warn("Couldn't write contents to '%s'", path);
 	else if ((size_t)n < sz)
 		log_warnx("Short contents write to '%s' (%zd vs %zu)",
-		    _PATH_RESOLV_CONF, n, sz);
+		    path, n, sz);
 
 	close(fd);
 }
diff --git a/sbin/dhclient/privsep.c b/sbin/dhclient/privsep.c
index 64898a8e9e4..23e4ae96f4b 100644
--- a/sbin/dhclient/privsep.c
+++ b/sbin/dhclient/privsep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: privsep.c,v 1.46 2017/04/10 21:47:44 krw Exp $ */
+/*	$OpenBSD: privsep.c,v 1.47 2017/06/23 15:40:56 krw Exp $ */
 
 /*
  * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
@@ -90,7 +90,12 @@ dispatch_imsg(struct interface_info *ifi, struct imsgbuf *ibuf)
 			break;
 
 		case IMSG_WRITE_RESOLV_CONF:
-			priv_write_resolv_conf(ifi, &imsg);
+			if (imsg.hdr.len <= IMSG_HEADER_SIZE) {
+				log_warnx("short IMSG_WRITE_RESOLV_CONF");
+				return;
+			} else
+				priv_write_resolv_conf(ifi, imsg.data,
+				    imsg.hdr.len - IMSG_HEADER_SIZE);
 			break;
 
 		case IMSG_HUP:
diff --git a/sbin/dhclient/privsep.h b/sbin/dhclient/privsep.h
index ab94db67c31..3d367634bac 100644
--- a/sbin/dhclient/privsep.h
+++ b/sbin/dhclient/privsep.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: privsep.h,v 1.35 2017/04/11 13:59:27 krw Exp $ */
+/*	$OpenBSD: privsep.h,v 1.36 2017/06/23 15:40:56 krw Exp $ */
 
 /*
  * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
@@ -69,7 +69,7 @@ void	priv_flush_routes(struct interface_info *, struct imsg_flush_routes *);
 char	*resolv_conf_contents(struct interface_info *ifi, struct option_data *,
 	    struct option_data *, struct option_data *);
 void	write_resolv_conf(u_int8_t *, size_t);
-void	priv_write_resolv_conf(struct interface_info *, struct imsg *);
+void	priv_write_resolv_conf(struct interface_info *, u_int8_t *, size_t);
 
 void	priv_delete_address(struct interface_info *,
 	    struct imsg_delete_address *);