Index: dhcpleased.c
===================================================================
RCS file: /cvs/src/sbin/dhcpleased/dhcpleased.c,v
retrieving revision 1.23
diff -u -p -r1.23 dhcpleased.c
--- dhcpleased.c	4 Jan 2022 06:20:37 -0000	1.23
+++ dhcpleased.c	20 Mar 2022 04:14:26 -0000
@@ -97,7 +97,8 @@ static struct imsgev	*iev_engine;
 #ifndef SMALL
 struct dhcpleased_conf	*main_conf;
 #endif
-char			*conffile;
+const char		 default_conffile[] = _PATH_CONF_FILE;
+const char		*conffile = default_conffile;
 pid_t			 frontend_pid;
 pid_t			 engine_pid;
 
@@ -308,13 +309,8 @@ main(int argc, char *argv[])
 		warnx("control socket setup failed");
 #endif /* SMALL */
 
-	if (conffile != NULL) {
-		if (unveil(conffile, "r") == -1)
-			fatal("unveil %s", conffile);
-	} else {
-		if (unveil(_PATH_CONF_FILE, "r") == -1)
-			fatal("unveil %s", _PATH_CONF_FILE);
-	}
+	if (unveil(conffile, "r") == -1)
+		fatal("unveil %s", conffile);
 	if (unveil("/dev/bpf", "rw") == -1)
 		fatal("unveil /dev/bpf");
 
Index: dhcpleased.h
===================================================================
RCS file: /cvs/src/sbin/dhcpleased/dhcpleased.h,v
retrieving revision 1.13
diff -u -p -r1.13 dhcpleased.h
--- dhcpleased.h	4 Jan 2022 06:20:37 -0000	1.13
+++ dhcpleased.h	20 Mar 2022 04:14:26 -0000
@@ -318,7 +318,7 @@ int			*changed_ifaces(struct dhcpleased_
 void	print_config(struct dhcpleased_conf *);
 
 /* parse.y */
-struct dhcpleased_conf	*parse_config(char *);
+struct dhcpleased_conf	*parse_config(const char *);
 int			 cmdline_symset(char *);
 #else
 #define	sin_to_str(x...)	""
Index: parse.y
===================================================================
RCS file: /cvs/src/sbin/dhcpleased/parse.y,v
retrieving revision 1.6
diff -u -p -r1.6 parse.y
--- parse.y	4 Jan 2022 06:20:37 -0000	1.6
+++ parse.y	20 Mar 2022 04:14:26 -0000
@@ -720,16 +720,17 @@ popfile(void)
 }
 
 struct dhcpleased_conf *
-parse_config(char *filename)
+parse_config(const char *filename)
 {
+	extern const char default_conffile[];
 	struct sym		*sym, *next;
 
 	conf = config_new_empty();
 
-	file = pushfile(filename != NULL ? filename : _PATH_CONF_FILE, 0);
+	file = pushfile(filename, 0);
 	if (file == NULL) {
 		/* no default config file is fine */
-		if (errno == ENOENT && filename == NULL)
+		if (errno == ENOENT && filename == default_conffile)
 			return (conf);
 		log_warn("%s", filename);
 		free(conf);