[PATCH 2/9] main: Support main.conf.d/ files for overriding configs

Use the util conf.d support to read additional configs. The values in
these additional configs will override any existing configuration set in
the main.conf or any previous conf.d files.
---
 src/main.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/main.c b/src/main.c
index ddb28276..b1b4fd5a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -3,6 +3,7 @@
  *  Connection Manager
  *
  *  Copyright (C) 2007-2013  Intel Corporation. All rights reserved.
+ *  Copyright (C) 2025  Jolla Mobile Ltd. All right reserved.
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2 as
@@ -38,6 +39,7 @@
 #include <gdbus.h>
 
 #include "connman.h"
+#include "src/shared/util.h"
 
 #define CONF_ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]) - 1)
 
@@ -68,6 +70,8 @@
 
 #define MAINFILE "main.conf"
 #define CONFIGMAINFILE CONFIGDIR "/" MAINFILE
+#define CONFIGMAINDIR CONFIGMAINFILE ".d"
+#define CONFIGSUFFIX ".conf"
 
 #define GENERAL_GROUP "General"
 
@@ -1229,6 +1233,7 @@ int main(int argc, char *argv[])
 	DBusConnection *conn;
 	DBusError err;
 	guint signal;
+	int fs_err;
 
 	context = g_option_context_new(NULL);
 	g_option_context_add_main_entries(context, options, NULL);
@@ -1292,6 +1297,12 @@ int main(int argc, char *argv[])
 	else
 		config_init(option_config);
 
+	fs_err = util_read_config_files_from(CONFIGMAINDIR, CONFIGSUFFIX,
+				NULL, config_init);
+	if (fs_err && fs_err != -ENOTDIR)
+		connman_error("failed to read configs from %s: %s",
+				CONFIGMAINDIR, strerror(fs_err));
+
 	__connman_util_init();
 	__connman_inotify_init();
 	__connman_technology_init();
-- 
2.47.3