Add '-n' option to just parse dhclient.conf for errors.

ok jmc@ tb@

3 files changed, 38 insertions, 21 deletions

diff --git a/sbin/dhclient/dhclient.8 b/sbin/dhclient/dhclient.8
index e95b9bb33d0..539ca5005b2 100644
--- a/sbin/dhclient/dhclient.8
+++ b/sbin/dhclient/dhclient.8
@@ -1,4 +1,4 @@
-.\" $OpenBSD: dhclient.8,v 1.34 2017/10/20 13:04:50 krw Exp $
+.\" $OpenBSD: dhclient.8,v 1.35 2017/10/27 15:10:16 krw Exp $
 .\"
 .\" Copyright (c) 1997 The Internet Software Consortium.
 .\" All rights reserved.
@@ -35,7 +35,7 @@
 .\" Enterprises.  To learn more about the Internet Software Consortium,
 .\" see ``http://www.isc.org/isc''.  To learn more about Vixie
 .\" Enterprises, see ``http://www.vix.com''.
-.Dd $Mdocdate: October 20 2017 $
+.Dd $Mdocdate: October 27 2017 $
 .Dt DHCLIENT 8
 .Os
 .Sh NAME
@@ -43,7 +43,7 @@
 .Nd Dynamic Host Configuration Protocol (DHCP) client
 .Sh SYNOPSIS
 .Nm
-.Op Fl d | q
+.Op Fl dnq
 .Op Fl c Ar file
 .Op Fl i Ar options
 .Op Fl L Ar file
@@ -120,10 +120,19 @@ will be the modified lease bound to the interface.
 Specify an alternate location to
 .Pa /var/db/dhclient.leases . Ns Aq Ar IFNAME
 for the leases file.
+.It Fl n
+Configtest mode.
+Only check the configuration file for validity.
 .It Fl q
 Forces
 .Nm
 to be less verbose on startup.
+.Fl q
+has no effect if either
+.Fl d
+or
+.Fl n
+is also present.
 .El
 .Pp
 The DHCP protocol allows a host to contact a central server which
diff --git a/sbin/dhclient/dhclient.c b/sbin/dhclient/dhclient.c
index 883a136be19..714fb733e67 100644
--- a/sbin/dhclient/dhclient.c
+++ b/sbin/dhclient/dhclient.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dhclient.c,v 1.515 2017/10/23 13:01:20 krw Exp $	*/
+/*	$OpenBSD: dhclient.c,v 1.516 2017/10/27 15:10:16 krw Exp $	*/
 
 /*
  * Copyright 2004 Henning Brauer <henning@openbsd.org>
@@ -103,7 +103,7 @@ char path_option_db[PATH_MAX];
 
 int log_perror = 1;
 int nullfd = -1;
-int daemonize = 1;
+int cmd_opts;
 
 volatile sig_atomic_t quit;
 
@@ -432,7 +432,7 @@ main(int argc, char *argv[])
 	ssize_t			 tailn;
 	int			 fd, socket_fd[2];
 	int			 rtfilter, ioctlfd, routefd, tailfd;
-	int			 ch, q_flag, d_flag;
+	int			 ch;
 
 	saved_argv = argv;
 
@@ -444,14 +444,13 @@ main(int argc, char *argv[])
 	log_init(log_perror, LOG_DAEMON);
 	log_setverbose(1);
 
-	q_flag = d_flag = 0;
-	while ((ch = getopt(argc, argv, "c:di:l:L:q")) != -1)
+	while ((ch = getopt(argc, argv, "c:di:l:L:nq")) != -1)
 		switch (ch) {
 		case 'c':
 			path_dhclient_conf = optarg;
 			break;
 		case 'd':
-			d_flag = 1;
+			cmd_opts |= OPT_FOREGROUND;
 			break;
 		case 'i':
 			ignore_list = optarg;
@@ -472,8 +471,11 @@ main(int argc, char *argv[])
 					    path_option_db);
 			}
 			break;
+		case 'n':
+			cmd_opts |= OPT_NOACTION;
+			break;
 		case 'q':
-			q_flag = 1;
+			cmd_opts |= OPT_QUIET;
 			break;
 		default:
 			usage();
@@ -482,13 +484,13 @@ main(int argc, char *argv[])
 	argc -= optind;
 	argv += optind;
 
-	if (argc != 1 || (q_flag != 0 && d_flag != 0))
+	if (argc != 1)
 		usage();
 
-	if (d_flag != 0)
-		daemonize = 0;
+	if ((cmd_opts & (OPT_FOREGROUND | OPT_NOACTION)) != 0)
+		cmd_opts &= ~OPT_QUIET;
 
-	if (q_flag != 0)
+	if ((cmd_opts & OPT_QUIET) != 0)
 		log_perror = 0;
 
 	log_init(log_perror, LOG_DAEMON);
@@ -543,9 +545,11 @@ main(int argc, char *argv[])
 	config = calloc(1, sizeof(*config));
 	if (config == NULL)
 		fatal("config");
-
 	read_client_conf(ifi->name);
 
+	if ((cmd_opts & OPT_NOACTION) != 0)
+		return 0;
+
 	/*
 	 * Set default client identifier, if needed, *before* reading
 	 * the leases file! Changes to the lladdr will trigger a restart
@@ -660,7 +664,7 @@ main(int argc, char *argv[])
 
 	endpwent();
 
-	if (daemonize != 0) {
+	if ((cmd_opts & OPT_FOREGROUND) == 0) {
 		if (pledge("stdio inet dns route proc", NULL) == -1)
 			fatal("pledge");
 	} else {
@@ -690,7 +694,7 @@ usage(void)
 	extern char	*__progname;
 
 	fprintf(stderr,
-	    "usage: %s [-d | -q] [-c file] [-i options] [-L file] "
+	    "usage: %s [-dnq ] [-c file] [-i options] [-L file] "
 	    "[-l file] interface\n", __progname);
 	exit(1);
 }
@@ -1973,12 +1977,12 @@ lease_as_string(char *ifname, char *type, struct client_lease *lease)
 void
 go_daemon(const char *name)
 {
-	static int	 state = 0;
+	static int	 daemonized = 0;
 
-	if (daemonize == 0 || state != 0)
+	if ((cmd_opts & OPT_FOREGROUND) != 0 || daemonized != 0)
 		return;
 
-	state = 1;
+	daemonized = 1;
 
 	if (rdaemon(nullfd) == -1)
 		fatal("daemonize");
diff --git a/sbin/dhclient/dhcpd.h b/sbin/dhclient/dhcpd.h
index e15371f2e11..2142e95a2ea 100644
--- a/sbin/dhclient/dhcpd.h
+++ b/sbin/dhclient/dhcpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dhcpd.h,v 1.233 2017/10/23 13:01:20 krw Exp $	*/
+/*	$OpenBSD: dhcpd.h,v 1.234 2017/10/27 15:10:16 krw Exp $	*/
 
 /*
  * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
@@ -212,6 +212,10 @@ extern char			*log_procname;
 extern struct client_config	*config;
 extern struct imsgbuf		*unpriv_ibuf;
 extern volatile sig_atomic_t	 quit;
+extern int			 cmd_opts;
+#define		OPT_NOACTION	1
+#define		OPT_QUIET	2
+#define		OPT_FOREGROUND	4
 
 void		 dhcpoffer(struct interface_info *, struct option_data *,
     char *);