net: config: init: sntp: use connection manager

Add option to use the connection manager to
schedule a (re-) sync on connection and diabeling the
work, when there is no connection.

Signed-off-by: Fin Maaß <f.maass@vogl-electronic.com>

Author: maass-hamburg

subsys/net/lib/config/Kconfig

@@ -257,5 +257,14 @@ config NET_CONFIG_SNTP_INIT_RESYNC_ON_FAILURE_INTERVAL
 	  If the SNTP request fails, then this is the interval to wait
 	  before trying again.
 
+config NET_CONFIG_SNTP_INIT_USE_CONNECTION_MANAGER
+	bool "Use connection manager to start and stop SNTP client"
+	default y
+	depends on NET_CONNECTION_MANAGER
+	help
+	  If this option is set, then the connection manager is used to
+	  start and stop the SNTP server. This way an SNTP request is
+	  also sent everytime when the network connection is established.
+
 endif # NET_CONFIG_SNTP_INIT_RESYNC
 endif # NET_CONFIG_CLOCK_SNTP_INIT

subsys/net/lib/config/init.c

@@ -546,7 +546,8 @@ int net_config_init_app(const struct device *dev, const char *app_info)
 		NET_ERR("Network initialization failed (%d)", ret);
 	}
 
-	if (IS_ENABLED(CONFIG_NET_CONFIG_CLOCK_SNTP_INIT)) {
+	if (IS_ENABLED(CONFIG_NET_CONFIG_CLOCK_SNTP_INIT) &&
+	    !IS_ENABLED(CONFIG_NET_CONFIG_SNTP_INIT_USE_CONNECTION_MANAGER)) {
 		net_init_clock_via_sntp();
 	}
 

subsys/net/lib/config/init_clock_sntp.c

@@ -10,6 +10,7 @@ LOG_MODULE_DECLARE(net_config, CONFIG_NET_CONFIG_LOG_LEVEL);
 
 #include <errno.h>
 #include <zephyr/net/net_if.h>
+#include <zephyr/net/net_mgmt.h>
 #include <zephyr/net/sntp.h>
 #include <zephyr/posix/time.h>
 
@@ -86,3 +87,24 @@ static void sntp_resync_handler(struct k_work *work)
 	LOG_DBG("Time resynced using SNTP");
 }
 #endif /* CONFIG_NET_CONFIG_SNTP_INIT_RESYNC */
+
+#ifdef CONFIG_NET_CONFIG_SNTP_INIT_USE_CONNECTION_MANAGER
+static void l4_event_handler(uint32_t mgmt_event, struct net_if *iface, void *info,
+			     size_t info_length, void *user_data)
+{
+	ARG_UNUSED(iface);
+	ARG_UNUSED(info);
+	ARG_UNUSED(info_length);
+	ARG_UNUSED(user_data);
+
+	if (mgmt_event == NET_EVENT_L4_CONNECTED) {
+		k_work_reschedule(&sntp_resync_work_handle, K_NO_WAIT);
+	} else if (mgmt_event == NET_EVENT_L4_DISCONNECTED) {
+		k_work_cancel_delayable(&sntp_resync_work_handle);
+	}
+}
+
+NET_MGMT_REGISTER_EVENT_HANDLER(sntp_init_event_handler,
+				NET_EVENT_L4_CONNECTED | NET_EVENT_L4_DISCONNECTED,
+				&l4_event_handler, NULL);
+#endif /* CONFIG_LOG_BACKEND_NET_USE_CONNECTION_MANAGER */